Study of multi-dimensional radiative energy transfer in molecular gases

NASA Technical Reports Server (NTRS)

Liu, Jiwen; Tiwari, S. N.

1993-01-01

The Monte Carlo method (MCM) is applied to analyze radiative heat transfer in nongray gases. The nongray model employed is based on the statistical arrow band model with an exponential-tailed inverse intensity distribution. Consideration of spectral correlation results in some distinguishing features of the Monte Carlo formulations. Validation of the Monte Carlo formulations has been conducted by comparing results of this method with other solutions. Extension of a one-dimensional problem to a multi-dimensional problem requires some special treatments in the Monte Carlo analysis. Use of different assumptions results in different sets of Monte Carlo formulations. The nongray narrow band formulations provide the most accurate results.

Mathematical modeling of radiative-conductive heat transfer in semitransparent medium with phase change

NASA Astrophysics Data System (ADS)

Savvinova, Nadezhda A.; Sleptsov, Semen D.; Rubtsov, Nikolai A.

2017-11-01

A mathematical phase change model is a formulation of the Stefan problem. Various formulations of the Stefan problem modeling of radiative-conductive heat transfer during melting or solidification of a semitransparent material are presented. Analysis of numerical results show that the radiative heat transfer has a significant effect on temperature distributions during melting (solidification) of the semitransparent material. In this paper conditions for application of various statements of the Stefan problem are analyzed.

Overview of physiological principles to support thermal balance and comfort of astronauts in open space and on planetary surfaces

NASA Astrophysics Data System (ADS)

Koscheyev, Victor S.; Coca, Aitor; Leon, Gloria R.

2007-02-01

Although specialists have attempted to improve the space suit to provide better protection in open space or on planetary surfaces, there has been a relative lack of attention to features of human thermoregulatory processes that influence comfort and therefore have an impact on the effectiveness of protective equipment. Our findings showed that different body tissues transfer heat in/out of the body in a different manner. There are also individual differences in thermal transfer through body areas with different proportions of tissues; therefore, data on the thermal profile of each astronaut needs to be used to estimate the optimal body areas for heat/cold transfer in and out of the body in an individually tailored cooling/warming garment. Principles for supporting thermal comfort in space were formulated based on a series of studies to evaluate the human body's response to uniform/nonuniform thermal conditions on the body surface. We conclude that future space suit design and comfort support of astronauts can be easier and more effective if these principles are incorporated.

Polyimides formulated from a partially fluorinated diamine for aerospace tribological applications

NASA Technical Reports Server (NTRS)

Fusaro, R. L.

1983-01-01

Preliminary tribological studies on polyimides formulated from the diamine 2,2-bis 4-(4-aminophenoxy)phenyl hexafluorapane (4-BDAF) indicate that polyimides formulated from this diamine have excellent potential for high temperature tribological applications. The dianhydrides used to make the polyimides were pyromellitic (PMDA) and benzophenonetetracarboxylic acid (BTDA). Friction and wear studies at 25 and 200 C indicate that polyimides formulated using 50 mole percent of the PMDA dianhydride and 50 mole percent of the BTDA dianhydride perform better than polyimides formulated solely with the BTDA dianhydride. Graphite fiber reinforced polyimide composites were formulated with the polyimide made from the BTDA dianhydride, both graphitic and non-graphitic fibers were evaluated. Graphitic fibers produced better tribological results, since thin, flowing, "layer-like' transfer films were produced which did not build-up with long sliding durations. Non-graphitic fibers did not produce this type of transfer.

Investigating potential transferability of place-based research in land system science

NASA Astrophysics Data System (ADS)

Václavík, Tomáš; Langerwisch, Fanny; Cotter, Marc; Fick, Johanna; Häuser, Inga; Hotes, Stefan; Kamp, Johannes; Settele, Josef; Spangenberg, Joachim H.; Seppelt, Ralf

2016-09-01

Much of our knowledge about land use and ecosystem services in interrelated social-ecological systems is derived from place-based research. While local and regional case studies provide valuable insights, it is often unclear how relevant this research is beyond the study areas. Drawing generalized conclusions about practical solutions to land management from local observations and formulating hypotheses applicable to other places in the world requires that we identify patterns of land systems that are similar to those represented by the case study. Here, we utilize the previously developed concept of land system archetypes to investigate potential transferability of research from twelve regional projects implemented in a large joint research framework that focus on issues of sustainable land management across four continents. For each project, we characterize its project archetype, i.e. the unique land system based on a synthesis of more than 30 datasets of land-use intensity, environmental conditions and socioeconomic indicators. We estimate the transferability potential of project research by calculating the statistical similarity of locations across the world to the project archetype, assuming higher transferability potentials in locations with similar land system characteristics. Results show that areas with high transferability potentials are typically clustered around project sites but for some case studies can be found in regions that are geographically distant, especially when values of considered variables are close to the global mean or where the project archetype is driven by large-scale environmental or socioeconomic conditions. Using specific examples from the local case studies, we highlight the merit of our approach and discuss the differences between local realities and information captured in global datasets. The proposed method provides a blueprint for large research programs to assess potential transferability of place-based studies to other geographical areas and to indicate possible gaps in research efforts.

Energy Harvesting Based Body Area Networks for Smart Health.

PubMed

Hao, Yixue; Peng, Limei; Lu, Huimin; Hassan, Mohammad Mehedi; Alamri, Atif

2017-07-10

Body area networks (BANs) are configured with a great number of ultra-low power consumption wearable devices, which constantly monitor physiological signals of the human body and thus realize intelligent monitoring. However, the collection and transfer of human body signals consume energy, and considering the comfort demand of wearable devices, both the size and the capacity of a wearable device's battery are limited. Thus, minimizing the energy consumption of wearable devices and optimizing the BAN energy efficiency is still a challenging problem. Therefore, in this paper, we propose an energy harvesting-based BAN for smart health and discuss an optimal resource allocation scheme to improve BAN energy efficiency. Specifically, firstly, considering energy harvesting in a BAN and the time limits of human body signal transfer, we formulate the energy efficiency optimization problem of time division for wireless energy transfer and wireless information transfer. Secondly, we convert the optimization problem into a convex optimization problem under a linear constraint and propose a closed-form solution to the problem. Finally, simulation results proved that when the size of data acquired by the wearable devices is small, the proportion of energy consumed by the circuit and signal acquisition of the wearable devices is big, and when the size of data acquired by the wearable devices is big, the energy consumed by the signal transfer of the wearable device is decisive.

Energy Harvesting Based Body Area Networks for Smart Health

PubMed Central

Hao, Yixue; Peng, Limei; Alamri, Atif

2017-01-01

Body area networks (BANs) are configured with a great number of ultra-low power consumption wearable devices, which constantly monitor physiological signals of the human body and thus realize intelligent monitoring. However, the collection and transfer of human body signals consume energy, and considering the comfort demand of wearable devices, both the size and the capacity of a wearable device’s battery are limited. Thus, minimizing the energy consumption of wearable devices and optimizing the BAN energy efficiency is still a challenging problem. Therefore, in this paper, we propose an energy harvesting-based BAN for smart health and discuss an optimal resource allocation scheme to improve BAN energy efficiency. Specifically, firstly, considering energy harvesting in a BAN and the time limits of human body signal transfer, we formulate the energy efficiency optimization problem of time division for wireless energy transfer and wireless information transfer. Secondly, we convert the optimization problem into a convex optimization problem under a linear constraint and propose a closed-form solution to the problem. Finally, simulation results proved that when the size of data acquired by the wearable devices is small, the proportion of energy consumed by the circuit and signal acquisition of the wearable devices is big, and when the size of data acquired by the wearable devices is big, the energy consumed by the signal transfer of the wearable device is decisive. PMID:28698501

Dissipation, intermittency, and singularities in incompressible turbulent flows

NASA Astrophysics Data System (ADS)

Debue, P.; Shukla, V.; Kuzzay, D.; Faranda, D.; Saw, E.-W.; Daviaud, F.; Dubrulle, B.

2018-05-01

We examine the connection between the singularities or quasisingularities in the solutions of the incompressible Navier-Stokes equation (INSE) and the local energy transfer and dissipation, in order to explore in detail how the former contributes to the phenomenon of intermittency. We do so by analyzing the velocity fields (a) measured in the experiments on the turbulent von Kármán swirling flow at high Reynolds numbers and (b) obtained from the direct numerical simulations of the INSE at a moderate resolution. To compute the local interscale energy transfer and viscous dissipation in experimental and supporting numerical data, we use the weak solution formulation generalization of the Kármán-Howarth-Monin equation. In the presence of a singularity in the velocity field, this formulation yields a nonzero dissipation (inertial dissipation) in the limit of an infinite resolution. Moreover, at finite resolutions, it provides an expression for local interscale energy transfers down to the scale where the energy is dissipated by viscosity. In the presence of a quasisingularity that is regularized by viscosity, the formulation provides the contribution to the viscous dissipation due to the presence of the quasisingularity. Therefore, our formulation provides a concrete support to the general multifractal description of the intermittency. We present the maps and statistics of the interscale energy transfer and show that the extreme events of this transfer govern the intermittency corrections and are compatible with a refined similarity hypothesis based on this transfer. We characterize the probability distribution functions of these extreme events via generalized Pareto distribution analysis and find that the widths of the tails are compatible with a similarity of the second kind. Finally, we make a connection between the topological and the statistical properties of the extreme events of the interscale energy transfer field and its multifractal properties.

Infrared radiative energy transfer in gaseous systems

NASA Technical Reports Server (NTRS)

Tiwari, Surendra N.

1991-01-01

Analyses and numerical procedures are presented to investigate the radiative interactions in various energy transfer processes in gaseous systems. Both gray and non-gray radiative formulations for absorption and emission by molecular gases are presented. The gray gas formulations are based on the Planck mean absorption coefficient and the non-gray formulations are based on the wide band model correlations for molecular absorption. Various relations for the radiative flux and divergence of radiative flux are developed. These are useful for different flow conditions and physical problems. Specific plans for obtaining extensive results for different cases are presented. The procedure developed was applied to several realistic problems. Results of selected studies are presented.

Fem Formulation of Heat Transfer in Cylindrical Porous Medium

NASA Astrophysics Data System (ADS)

Azeem; Khaleed, H. M. T.; Soudagar, Manzoor Elahi M.

2017-08-01

Heat transfer in porous medium can be derived from the fundamental laws of flow in porous region ass given by Henry Darcy. The fluid flow and energy transport inside the porous medium can be described with the help of momentum and energy equations. The heat transfer in cylindrical porous medium differs from its counterpart in radial and axial coordinates. The present work is focused to discuss the finite element formulation of heat transfer in cylindrical porous medium. The basic partial differential equations are derived using Darcy law which is the converted into a set of algebraic equations with the help of finite element method. The resulting equations are solved by matrix method for two solution variables involved in the coupled equations.

Heat transfer characteristics within an array of impinging jets. Effects of crossflow temperature relative to jet temperature

NASA Technical Reports Server (NTRS)

Florschuetz, L. W.; Su, C. C.

1985-01-01

Spanwise average heat fluxes, resolved in the streamwise direction to one stream-wise hole spacing were measured for two-dimensional arrays of circular air jets impinging on a heat transfer surface parallel to the jet orifice plate. The jet flow, after impingement, was constrained to exit in a single direction along the channel formed by the jet orifice plate and heat transfer surface. The crossflow originated from the jets following impingement and an initial crossflow was present that approached the array through an upstream extension of the channel. The regional average heat fluxes are considered as a function of parameters associated with corresponding individual spanwise rows within the array. A linear superposition model was employed to formulate appropriate governing parameters for the individual row domain. The effects of flow history upstream of an individual row domain are also considered. The results are formulated in terms of individual spanwise row parameters. A corresponding set of streamwise resolved heat transfer characteristics formulated in terms of flow and geometric parameters characterizing the overall arrays is described.

Simulation of global oceanic upper layers forced at the surface by an optimal bulk formulation derived from multi-campaign measurements.

NASA Astrophysics Data System (ADS)

Garric, G.; Pirani, A.; Belamari, S.; Caniaux, G.

2006-12-01

order to improve the air/sea interface for the future MERCATOR global ocean operational system, we have implemented the new bulk formulation developed by METEO-FRANCE (French Meteo office) in the MERCATOR 2 degree global ocean-ice coupled model (ORCA2/LIM). A single bulk formulation for the drag, temperature and moisture exchange coefficients is derived from an extended consistent database gathering 10 years of measurements issued from five experiments dedicated to air-sea fluxes estimates (SEMAPHORE, CATCH, FETCH, EQUALANT99 and POMME) in various oceanic basins (from Northern to equatorial Atlantic). The available database (ALBATROS) cover the widest range of atmospheric and oceanic conditions, from very light (0.3 m/s) to very strong (up to 29 m/s) wind speeds, and from unstable to extremely stable atmospheric boundary layer stratification. We have defined a work strategy to test this new formulation in a global oceanic context, by using this multi- campaign bulk formulation to derive air-sea fluxes from base meteorological variables produces by the ECMWF (European Centre for Medium Range and Weather Forecast) atmospheric forecast model, in order to get surface boundary conditions for ORCA2/LIM. The simulated oceanic upper layers forced at the surface by the previous air/sea interface are compared to those forced by the optimal bulk formulation. Consecutively with generally weaker transfer coefficient, the latter formulation reduces the cold bias in the equatorial Pacific and increases the too weak summer sea ice extent in Antarctica. Compared to a recent mixed layer depth (MLD) climatology, the optimal bulk formulation reduces also the too deep simulated MLDs. Comparison with in situ temperature and salinity profiles in different areas allowed us to evaluate the impact of changing the air/sea interface in the vertical structure.

Radiative interactions in multi-dimensional chemically reacting flows using Monte Carlo simulations

NASA Technical Reports Server (NTRS)

Liu, Jiwen; Tiwari, Surendra N.

1994-01-01

The Monte Carlo method (MCM) is applied to analyze radiative heat transfer in nongray gases. The nongray model employed is based on the statistical narrow band model with an exponential-tailed inverse intensity distribution. The amount and transfer of the emitted radiative energy in a finite volume element within a medium are considered in an exact manner. The spectral correlation between transmittances of two different segments of the same path in a medium makes the statistical relationship different from the conventional relationship, which only provides the non-correlated results for nongray methods is discussed. Validation of the Monte Carlo formulations is conducted by comparing results of this method of other solutions. In order to further establish the validity of the MCM, a relatively simple problem of radiative interactions in laminar parallel plate flows is considered. One-dimensional correlated Monte Carlo formulations are applied to investigate radiative heat transfer. The nongray Monte Carlo solutions are also obtained for the same problem and they also essentially match the available analytical solutions. the exact correlated and non-correlated Monte Carlo formulations are very complicated for multi-dimensional systems. However, by introducing the assumption of an infinitesimal volume element, the approximate correlated and non-correlated formulations are obtained which are much simpler than the exact formulations. Consideration of different problems and comparison of different solutions reveal that the approximate and exact correlated solutions agree very well, and so do the approximate and exact non-correlated solutions. However, the two non-correlated solutions have no physical meaning because they significantly differ from the correlated solutions. An accurate prediction of radiative heat transfer in any nongray and multi-dimensional system is possible by using the approximate correlated formulations. Radiative interactions are investigated in chemically reacting compressible flows of premixed hydrogen and air in an expanding nozzle. The governing equations are based on the fully elliptic Navier-Stokes equations. Chemical reaction mechanisms were described by a finite rate chemistry model. The correlated Monte Carlo method developed earlier was employed to simulate multi-dimensional radiative heat transfer. Results obtained demonstrate that radiative effects on the flowfield are minimal but radiative effects on the wall heat transfer are significant. Extensive parametric studies are conducted to investigate the effects of equivalence ratio, wall temperature, inlet flow temperature, and nozzle size on the radiative and conductive wall fluxes.

The influence of direct compression powder blend transfer method from the container to the tablet press on product critical quality attributes: a case study.

PubMed

Teżyk, Michał; Jakubowska, Emilia; Milczewska, Kasylda; Milanowski, Bartłomiej; Voelkel, Adam; Lulek, Janina

2017-06-01

The aim of this article is to compare the gravitational powder blend loading method to the tablet press and manual loading in terms of their influence on tablets' critical quality attributes (CQA). The results of the study can be of practical relevance to the pharmaceutical industry in the area of direct compression of low-dose formulations, which could be prone to content uniformity (CU) issues. In the preliminary study, particle size distribution (PSD) and surface energy of raw materials were determined using laser diffraction method and inverse gas chromatography, respectively. For trials purpose, a formulation containing two pharmaceutical ingredients (APIs) was used. Tablet samples were collected during the compression progress to analyze their CQAs, namely assay and CU. Results obtained during trials indicate that tested direct compression powder blend is sensitive to applied powder handling method. Mild increase in both APIs content was observed during manual scooping. Gravitational approach (based on discharge into the drum) resulted in a decrease in CU, which is connected to a more pronounced assay increase at the end of tableting than in the case of manual loading. The correct design of blend transfer over single unit processes is an important issue and should be investigated during the development phase since it may influence the final product CQAs. The manual scooping method, although simplistic, can be a temporary solution to improve the results of API's content and uniformity when compared to industrial gravitational transfer.

Green's function solution to heat transfer of a transparent gas through a tube

NASA Technical Reports Server (NTRS)

Frankel, J. I.

1989-01-01

A heat transfer analysis of a transparent gas flowing through a circular tube of finite thickness is presented. This study includes the effects of wall conduction, internal radiative exchange, and convective heat transfer. The natural mathematical formulation produces a nonlinear, integrodifferential equation governing the wall temperature and an ordinary differential equation describing the gas temperature. This investigation proposes to convert the original system of equations into an equivalent system of integral equations. The Green's function method permits the conversion of an integrodifferential equation into a pure integral equation. The proposed integral formulation and subsequent computational procedure are shown to be stable and accurate.

An investigation of the accuracy of the Merkel equation for evaporative cooling tower calculations. Waste heat management

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

Yadigaroglu, G.; Pastor, E.J.

1974-01-01

The exact differential equations governing heat and mass transfer and air flow in an evaporative, natural-draft cooling tower are presented. The Merkel equation is then derived starting from this exact formulation and showing all the approximations involved. The Merkel formulation lumps the sensible and the latent heat transfer together and considers a single enthalpy-difference driving force for the total heat transfer. The effect of the approximations inherent in the Merkel equation is investigated and analyzed by a series of parametric numerical calculations of cooling tower performance under various ambient conditions and load conditions.

Estimating Dermal Transfer of Copper Particles from the ...

EPA Pesticide Factsheets

Lumber pressure-treated with micronized copper was examined for the release of copper and copper micro/nanoparticles using a surface wipe method to simulate dermal transfer. In 2003, the wood industry began replacing CCA treated lumber products for residential use with copper based formulations. Micronized copper (nano to micron sized particles) has become the preferred treatment formulation. There is a lack of information on the release of copper, the fate of the particles during dermal contact, and the copper exposure level to children from hand-to-mouth transfer. For the current study, three treated lumber products, two micronized copper and one ionic copper, were purchased from commercial retailers. The boards were left to weather outdoors for approximately 1 year. Over the year time period, hand wipe samples were collected periodically to determine copper transfer from the wood surfaces. The two micronized formulations and the ionic formulation released similar levels of total copper. The amount of copper released was high initially, but decreased to a constant level (~1.5 mg m-2) after the first month of outdoor exposure. Copper particles were identified on the sampling cloths during the first two months of the experiment, after which the levels of copper were insufficient to collect interpretable data. After 1 month, the particles exhibited minimal changes in shape and size. At the end of 2-months, significant deterioration of the particles was

40 CFR 152.30 - Pesticides that may be transferred, sold, or distributed without registration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... transfer is solely for the purpose of further formulation, packaging, or labeling into a product that is registered; (2) Each active ingredient in the pesticide, at the time of transfer, is present as a result of...

40 CFR 152.30 - Pesticides that may be transferred, sold, or distributed without registration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... transfer is solely for the purpose of further formulation, packaging, or labeling into a product that is registered; (2) Each active ingredient in the pesticide, at the time of transfer, is present as a result of...

A tensor formulation of the equation of transfer for spherically symmetric flows. [radiative transfer in seven dimensional Riemannian space

NASA Technical Reports Server (NTRS)

Haisch, B. M.

1976-01-01

A tensor formulation of the equation of radiative transfer is derived in a seven-dimensional Riemannian space such that the resulting equation constitutes a divergence in any coordinate system. After being transformed to a spherically symmetric comoving coordinate system, the transfer equation contains partial derivatives in angle and frequency, as well as optical depth due to the effects of aberration and the Doppler shift. However, by virtue of the divergence form of this equation, the divergence theorem may be applied to yield a numerical differencing scheme which is expected to be stable and to conserve luminosity. It is shown that the equation of transfer derived by this method in a Lagrangian coordinate system may be reduced to that given by Castor (1972), although it is, of course, desirable to leave the equation in divergence form.

Electrode redox reactions with polarizable molecules.

PubMed

Matyushov, Dmitry V

2018-04-21

A theory of redox reactions involving electron transfer between a metal electrode and a polarizable molecule in solution is formulated. Both the existence of molecular polarizability and its ability to change due to electron transfer distinguish this problem from classical theories of interfacial electrochemistry. When the polarizability is different between the oxidized and reduced states, the statistics of thermal fluctuations driving the reactant over the activation barrier becomes non-Gaussian. The problem of electron transfer is formulated as crossing of two non-parabolic free energy surfaces. An analytical solution for these free energy surfaces is provided and the activation barrier of electrode electron transfer is given in terms of two reorganization energies corresponding to the oxidized and reduced states of the molecule in solution. The new non-Gaussian theory is, therefore, based on two theory parameters in contrast to one-parameter Marcus formulation for electrode reactions. The theory, which is consistent with the Nernst equation, predicts asymmetry between the cathodic and anodic branches of the electrode current. They show different slopes at small electrode overpotentials and become curved at larger overpotentials. However, the curvature of the Tafel plot is reduced compared to the Marcus-Hush model and approaches the empirical Butler-Volmer form with different transfer coefficients for the anodic and cathodic currents.

Electrode redox reactions with polarizable molecules

NASA Astrophysics Data System (ADS)

Matyushov, Dmitry V.

2018-04-01

A theory of redox reactions involving electron transfer between a metal electrode and a polarizable molecule in solution is formulated. Both the existence of molecular polarizability and its ability to change due to electron transfer distinguish this problem from classical theories of interfacial electrochemistry. When the polarizability is different between the oxidized and reduced states, the statistics of thermal fluctuations driving the reactant over the activation barrier becomes non-Gaussian. The problem of electron transfer is formulated as crossing of two non-parabolic free energy surfaces. An analytical solution for these free energy surfaces is provided and the activation barrier of electrode electron transfer is given in terms of two reorganization energies corresponding to the oxidized and reduced states of the molecule in solution. The new non-Gaussian theory is, therefore, based on two theory parameters in contrast to one-parameter Marcus formulation for electrode reactions. The theory, which is consistent with the Nernst equation, predicts asymmetry between the cathodic and anodic branches of the electrode current. They show different slopes at small electrode overpotentials and become curved at larger overpotentials. However, the curvature of the Tafel plot is reduced compared to the Marcus-Hush model and approaches the empirical Butler-Volmer form with different transfer coefficients for the anodic and cathodic currents.

Uptake of indocyanine green by hamster sebaceous glands

NASA Astrophysics Data System (ADS)

McMillan, Kathleen; Lo, Kai-Ming; Wang, Zhi

2001-05-01

Photothermal injury to the sebaceous glands is a potential curative treatment for the common skin disease acne vulgaris. Accumulation of the exogenous chromophore indocyanine green in the sebaceous glands may be accomplished using an emulsion or liposomal formulation applied to the skin surface. An emulsion containing 0.09% by weight indocyanine green (ICG) was applied to the epidermis of hamster ears ex vivo and the flank organ in vivo. Fluorescence microscopy demonstrated selective accumulation of ICG in the underlying sebaceous glands. The concentration of ICG that may be expected to accumulate in sebaceous glands of humans was then estimated on the basis of the gland size and orifice area, for the case of topical application of a more concentrated 1% ICG liposomal formulation. Monte Carlo modeling and heat transfer calculations showed that the sebaceous glands containing the exogenous chromophore may be selectively damaged by pulsed 810 nm laser radiation in conjunction with cryogen spray cooling.

A p-version finite element method for steady incompressible fluid flow and convective heat transfer

NASA Technical Reports Server (NTRS)

Winterscheidt, Daniel L.

1993-01-01

A new p-version finite element formulation for steady, incompressible fluid flow and convective heat transfer problems is presented. The steady-state residual equations are obtained by considering a limiting case of the least-squares formulation for the transient problem. The method circumvents the Babuska-Brezzi condition, permitting the use of equal-order interpolation for velocity and pressure, without requiring the use of arbitrary parameters. Numerical results are presented to demonstrate the accuracy and generality of the method.

Thermoplasticity of coupled bodies in the case of stress-dependent heat transfer

NASA Technical Reports Server (NTRS)

Kilikovskaya, O. A.

1987-01-01

The problem of the thermal stresses in coupled deformable bodies is formulated for the case where the heat-transfer coefficient at the common boundary depends on the stress-strain state of the bodies (e.g., is a function of the normal pressure at the common boundary). Several one-dimensional problems are solved in this formulation. Among these problems is the determination of the thermal stresses in an n-layer plate and in a two-layer cylinder.

Two-Fluid Models and Interfacial Area Transport in Microgravity Condition

NASA Technical Reports Server (NTRS)

Ishii, Mamoru; Sun, Xiao-Dong; Vasavada, Shilp

2004-01-01

The objective of the present study is to develop a two-fluid model formulation with interfacial area transport equation applicable for microgravity conditions. The new model is expected to make a leapfrog improvement by furnishing the constitutive relations for the interfacial interaction terms with the interfacial area transport equation, which can dynamically model the changes of the interfacial structures. In the first year of this three-year project supported by the U.S. NASA, Office of Biological and Physics Research, the primary focus is to design and construct a ground-based, microgravity two-phase flow simulation facility, in which two immiscible fluids with close density will be used. In predicting the two-phase flow behaviors in any two-phase flow system, the interfacial transfer terms are among the most essential factors in the modeling. These interfacial transfer terms in a two-fluid model specify the rate of phase change, momentum exchange, and energy transfer at the interface between the two phases. For the two-phase flow under the microgravity condition, the stability of the fluid particle interface and the interfacial structures are quite different from those under normal gravity condition. The flow structure may not reach an equilibrium condition and the two fluids may be loosely coupled such that the inertia terms of each fluid should be considered separately by use of the two-fluid model. Previous studies indicated that, unless phase-interaction terms are accurately modeled in the two-fluid model, the complex modeling does not necessarily warrant an accurate solution.

Radiative heat transfer and nonequilibrium Casimir-Lifshitz force in many-body systems with planar geometry

NASA Astrophysics Data System (ADS)

Latella, Ivan; Ben-Abdallah, Philippe; Biehs, Svend-Age; Antezza, Mauro; Messina, Riccardo

2017-05-01

A general theory of photon-mediated energy and momentum transfer in N -body planar systems out of thermal equilibrium is introduced. It is based on the combination of the scattering theory and the fluctuational-electrodynamics approach in many-body systems. By making a Landauer-like formulation of the heat transfer problem, explicit formulas for the energy transmission coefficients between two distinct slabs as well as the self-coupling coefficients are derived and expressed in terms of the reflection and transmission coefficients of the single bodies. We also show how to calculate local equilibrium temperatures in such systems. An analogous formulation is introduced to quantify momentum transfer coefficients describing Casimir-Lifshitz forces out of thermal equilibrium. Forces at thermal equilibrium are readily obtained as a particular case. As an illustration of this general theoretical framework, we show on three-body systems how the presence of a fourth slab can impact equilibrium temperatures in heat-transfer problems and equilibrium positions resulting from the forces acting on the system.

An experimental investigation of convective heat transfer at evaporation of kerosene and water in the closed volume

NASA Astrophysics Data System (ADS)

Trushlyakov, V. I.; Lesnyak, I. Y.; Galfetti, L.

2017-09-01

An evaporation of kerosene and water was investigated based on convective heat transfer in the experimental setup simulating a typical volume of the fuel tank of the launch vehicle. Basic criteria of similarity used in choosing the design parameters of the setup, parameters of the coolant and model liquids, were numbers of Reynolds, Prandtl, Biot, and Nusselt. The used coolants were gases, including air and nitrogen; in addition, at the stage of preliminary experiments, products of combustion of hydroxyl-terminated polybutadiene (HTPB) were considered. Boundary conditions were taken for the liquid located on the plate in the form of "drop" and at its uniform film spread in the experimental model setup. On the basis of experimental investigations, the temperature values were obtained for the system "gas-liquid-wall", and areas of mass transfer surface and heat transfer coefficients of "gas-liquid" and "gas-plate" were determined for coolants (air and nitrogen) and for liquids (water and kerosene). The comparative analysis of the obtained results and the known data was carried out. Proposals for experiments using coolants based on HTPB combustion products have been formulated.

A probabilistic model of a porous heat exchanger

NASA Technical Reports Server (NTRS)

Agrawal, O. P.; Lin, X. A.

1995-01-01

This paper presents a probabilistic one-dimensional finite element model for heat transfer processes in porous heat exchangers. The Galerkin approach is used to develop the finite element matrices. Some of the submatrices are asymmetric due to the presence of the flow term. The Neumann expansion is used to write the temperature distribution as a series of random variables, and the expectation operator is applied to obtain the mean and deviation statistics. To demonstrate the feasibility of the formulation, a one-dimensional model of heat transfer phenomenon in superfluid flow through a porous media is considered. Results of this formulation agree well with the Monte-Carlo simulations and the analytical solutions. Although the numerical experiments are confined to parametric random variables, a formulation is presented to account for the random spatial variations.

The Vaccine Formulation Laboratory: a platform for access to adjuvants.

PubMed

Collin, Nicolas; Dubois, Patrice M

2011-07-01

Adjuvants are increasingly used by the vaccine research and development community, particularly for their ability to enhance immune responses and for their dose-sparing properties. However, they are not readily available to the majority of public sector vaccine research groups, and even those with access to suitable adjuvants may still fail in the development of their vaccines because of lack of knowledge on how to correctly formulate the adjuvants. This shortcoming led the World Health Organization to advocate for the establishment of the Vaccine Formulation Laboratory at the University of Lausanne, Switzerland. The primary mission of the laboratory is to transfer adjuvants and formulation technology free of intellectual property rights to academic institutions, small biotechnology companies and developing countries vaccine manufacturers. In this context, the transfer of an oil-in-water emulsion to Bio Farma, an Indonesian vaccine manufacturer, was initiated to increase domestic pandemic influenza vaccine production capacity as part of the national pandemic influenza preparedness plan. Copyright © 2011 Elsevier Ltd. All rights reserved.

Energy optimization for upstream data transfer in 802.15.4 beacon-enabled star formulation

NASA Astrophysics Data System (ADS)

Liu, Hua; Krishnamachari, Bhaskar

2008-08-01

Energy saving is one of the major concerns for low rate personal area networks. This paper models energy consumption for beacon-enabled time-slotted media accessing control cooperated with sleeping scheduling in a star network formulation for IEEE 802.15.4 standard. We investigate two different upstream (data transfer from devices to a network coordinator) strategies: a) tracking strategy: the devices wake up and check status (track the beacon) in each time slot; b) non-tracking strategy: nodes only wake-up upon data arriving and stay awake till data transmitted to the coordinator. We consider the tradeoff between energy cost and average data transmission delay for both strategies. Both scenarios are formulated as optimization problems and the optimal solutions are discussed. Our results show that different data arrival rate and system parameters (such as contention access period interval, upstream speed etc.) result in different strategies in terms of energy optimization with maximum delay constraints. Hence, according to different applications and system settings, different strategies might be chosen by each node to achieve energy optimization for both self-interested view and system view. We give the relation among the tunable parameters by formulas and plots to illustrate which strategy is better under corresponding parameters. There are two main points emphasized in our results with delay constraints: on one hand, when the system setting is fixed by coordinator, nodes in the network can intelligently change their strategies according to corresponding application data arrival rate; on the other hand, when the nodes' applications are known by the coordinator, the coordinator can tune the system parameters to achieve optimal system energy consumption.

Quantitative In Vitro Assessment of Liposome Stability and Drug Transfer Employing Asymmetrical Flow Field-Flow Fractionation (AF4).

PubMed

Holzschuh, Stephan; Kaeß, Kathrin; Fahr, Alfred; Decker, Christiane

2016-04-01

In the present study we introduce an efficient approach for a size-based separation of liposomes from plasma proteins employing AF4. We investigated vesicle stability and release behavior of the strongly lipophilic drug temoporfin from liposomes in human plasma for various incubation times at 37°C. We used the radioactive tracer cholesteryl oleyl ether (COE) or dipalmitoyl-phosphocholine (DPPC) as lipid markers and (14)C-labeled temoporfin. First, both lipid labels were examined for their suitability as liposome markers. Furthermore, the influence of plasma origin on liposome stability and drug transfer was investigated. The effect of membrane fluidity and PEGylation on vesicle stability and drug release characteristics was also analyzed. Surprisingly, we observed an enzymatic transfer of (3)H-COE to lipoproteins due to the cholesterol ester transfer protein (CETP) in human plasma in dependence on membrane rigidity and were able to inhibit this transfer by plasma preincubation with the CETP inhibitor torcetrapib. This effect was not seen when liposomes were incubated in rat plasma. DPPC labels suffered from hydrolysis effects during preparation and/or storage. Fluid liposomes were less stable in human plasma than their PEGylated analogues or a rigid formulation. In contrast, the transfer of the incorporated drug to lipoproteins was higher for the rigid formulations. The observed effects render COE-labels questionable for in vivo studies using CEPT-rich species. Here, choline labelled (14)C-DPPC was found to be the most promising alternative. Bilayer composition has a high influence on stability and drug release of a liposomal formulation in human plasma.

Modeling of heat and mass transfer processes for the gap-lyophilization system using the mannitol-trehalose-NaCl formulation.

PubMed

Kuu, Wei Y; Doty, Mark J; Nisipeanu, Eugen; Rebbeck, Christine L; Cho, Yong K; Smit, Mark H

2014-09-01

Gap freezing (GF) is a new concept that was developed to reduce the primary drying time using an alternative freezing process. The purpose of this investigation was to determine the gap-tray heat transfer coefficient, Kgtr , and to investigate the effect of gap lyophilization on cycle reduction of a mannitol-trehalose-NaCl (MTN) formulation. The values of Kgtr were measured using the product temperature profiles in three different configurations: (1) shelf freezing followed by shelf drying (denoted as SF-SD), (2) GF followed by SD (denoted as GF-SD), and (3) GF followed by gap drying (denoted as GF-GD). For the lyophilization cycle using shelf drying (SF-SD), 80% of the heat transferred during primary drying was from the bottom shelf to the vial, versus 20% via radiation from the top shelf. For the lyophilization cycle using gap drying (GF-GD), only 37% of the heat transferred during primary drying was from the bottom shelf to the vial versus 63% via radiation from the top shelf. Furthermore, GF in conjunction with annealing significantly reduces the dry layer resistance of the MTN formulation, which is the opposite of what was observed with a conventional freezing cycle. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Numerical analysis of the accuracy of bivariate quantile distributions utilizing copulas compared to the GUM supplement 2 for oil pressure balance uncertainties

NASA Astrophysics Data System (ADS)

Ramnath, Vishal

2017-11-01

In the field of pressure metrology the effective area is Ae = A0 (1 + λP) where A0 is the zero-pressure area and λ is the distortion coefficient and the conventional practise is to construct univariate probability density functions (PDFs) for A0 and λ. As a result analytical generalized non-Gaussian bivariate joint PDFs has not featured prominently in pressure metrology. Recently extended lambda distribution based quantile functions have been successfully utilized for summarizing univariate arbitrary PDF distributions of gas pressure balances. Motivated by this development we investigate the feasibility and utility of extending and applying quantile functions to systems which naturally exhibit bivariate PDFs. Our approach is to utilize the GUM Supplement 1 methodology to solve and generate Monte Carlo based multivariate uncertainty data for an oil based pressure balance laboratory standard that is used to generate known high pressures, and which are in turn cross-floated against another pressure balance transfer standard in order to deduce the transfer standard's respective area. We then numerically analyse the uncertainty data by formulating and constructing an approximate bivariate quantile distribution that directly couples A0 and λ in order to compare and contrast its accuracy to an exact GUM Supplement 2 based uncertainty quantification analysis.

Adaptive Same Frequency Repeater (SFR) Study

DTIC Science & Technology

1976-03-01

Formulation 13 (2) Evaluation of the Steady State Weights!.’.’.’!.*!!."!! 21 (3) Evaluation of the Composite Transfer Function.... 2^ (4) Simplified...well as possible the amplitude and phase of the composite coupling path. Because the coupling paths have frequency-dependent transfer functions...34), (35) and the notch filter and channel transfer .’unctions (3fi) and (39). The composite transfer function Hc(f ’ ^’.f) is then found and

An examination of three methods of psychodynamic formulation based on the same videotaped interview.

PubMed

Perry, J C; Luborsky, L; Silberschatz, G; Popp, C

1989-08-01

While psychodynamic theory and therapy are approaching their centennial, the science of psychodynamics is still in an earlier developmental stage. Any scientific field generates the most controversy and excitement when it is still developing. For psychodynamic psychology this means that its basic units of observation as well as its rules for justifying clinical inference in formulating and testing dynamic hypotheses require more development. In short, we are still evaluating different methods for both discovering and validating psychodynamic propositions. This is especially true for central features of dynamic psychology, including intrapsychic conflict, relationships, and transference patterns. This report compares three different methods for making a dynamic case formulation: 1) the Core Conflictual Relationship Theme (CCRT) of Luborsky (Crits-Christoph and Luborsky 1985a,b; Luborsky 1976, 1977, 1984, and companion paper in this issue; Levine and Luborsky 1981), 2) the Plan Diagnosis (PD) method of Silberschatz, Curtis and colleagues of the Mount Zion group (Caston 1986; Curtis and Silberschatz 1986; Rosenberg et al. 1986; Curtis et al. 1988) and, 3) the Idiographic Conflict Formulation (ICF) of Perry and Cooper (1985, 1986, and companion paper in this issue). Each has a slightly different focus. The CCRT focuses on relationship patterns as the central feature of individual dynamics and transference in or out of the treatment situation. The Plan Diagnosis focuses on dynamic features related to transference, resistance and insight in therapy. The Idiographic Conflict Formulation focuses on stress and internal conflict, and the individual's adaptation to them in or out of treatment.

Numerical marching techniques for fluid flows with heat transfer

NASA Technical Reports Server (NTRS)

Hornbeck, R. W.

1973-01-01

The finite difference formulation and method of solution is presented for a wide variety of fluid flow problems with associated heat transfer. Only a few direct results from these formulations are given as examples, since the book is intended primarily to serve a discussion of the techniques and as a starting point for further investigations; however, the formulations are sufficiently complete that a workable computer program may be written from them. In the appendixes a number of topics are discussed which are of interest with respect to the finite difference equations presented. These include a very rapid method for solving certain sets of linear algebraic equations, a discussion of numerical stability, the inherent error in flow rate for confined flow problems, and a method for obtaining high accuracy with a relatively small number of mesh points.

ESTIMATION OF THE RATE OF VOC EMISSIONS FROM SOLVENT-BASED INDOOR COATING MATERIALS BASED ON PRODUCT FORMULATION

EPA Science Inventory

Two computational methods are proposed for estimation of the emission rate of volatile organic compounds (VOCs) from solvent-based indoor coating materials based on the knowledge of product formulation. The first method utilizes two previously developed mass transfer models with ...

Combined Heat Transfer in High-Porosity High-Temperature Fibrous Insulations: Theory and Experimental Validation

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran; Cunnington, George R.; Miller, Steve D.; Knutson, Jeffry R.

2010-01-01

Combined radiation and conduction heat transfer through various high-temperature, high-porosity, unbonded (loose) fibrous insulations was modeled based on first principles. The diffusion approximation was used for modeling the radiation component of heat transfer in the optically thick insulations. The relevant parameters needed for the heat transfer model were derived from experimental data. Semi-empirical formulations were used to model the solid conduction contribution of heat transfer in fibrous insulations with the relevant parameters inferred from thermal conductivity measurements at cryogenic temperatures in a vacuum. The specific extinction coefficient for radiation heat transfer was obtained from high-temperature steady-state thermal measurements with large temperature gradients maintained across the sample thickness in a vacuum. Standard gas conduction modeling was used in the heat transfer formulation. This heat transfer modeling methodology was applied to silica, two types of alumina, and a zirconia-based fibrous insulation, and to a variation of opacified fibrous insulation (OFI). OFI is a class of insulations manufactured by embedding efficient ceramic opacifiers in various unbonded fibrous insulations to significantly attenuate the radiation component of heat transfer. The heat transfer modeling methodology was validated by comparison with more rigorous analytical solutions and with standard thermal conductivity measurements. The validated heat transfer model is applicable to various densities of these high-porosity insulations as long as the fiber properties are the same (index of refraction, size distribution, orientation, and length). Furthermore, the heat transfer data for these insulations can be obtained at any static pressure in any working gas environment without the need to perform tests in various gases at various pressures.

Topology synthesis and size optimization of morphing wing structures

NASA Astrophysics Data System (ADS)

Inoyama, Daisaku

This research demonstrates a novel topology and size optimization methodology for synthesis of distributed actuation systems with specific applications to morphing air vehicle structures. The main emphasis is placed on the topology and size optimization problem formulations and the development of computational modeling concepts. The analysis model is developed to meet several important criteria: It must allow a rigid-body displacement, as well as a variation in planform area, with minimum strain on structural members while retaining acceptable numerical stability for finite element analysis. Topology optimization is performed on a semi-ground structure with design variables that control the system configuration. In effect, the optimization process assigns morphing members as "soft" elements, non-morphing load-bearing members as "stiff' elements, and non-existent members as "voids." The optimization process also determines the optimum actuator placement, where each actuator is represented computationally by equal and opposite nodal forces with soft axial stiffness. In addition, the configuration of attachments that connect the morphing structure to a non-morphing structure is determined simultaneously. Several different optimization problem formulations are investigated to understand their potential benefits in solution quality, as well as meaningfulness of the formulations. Extensions and enhancements to the initial concept and problem formulations are made to accommodate multiple-configuration definitions. In addition, the principal issues on the external-load dependency and the reversibility of a design, as well as the appropriate selection of a reference configuration, are addressed in the research. The methodology to control actuator distributions and concentrations is also discussed. Finally, the strategy to transfer the topology solution to the sizing optimization is developed and cross-sectional areas of existent structural members are optimized under applied aerodynamic loads. That is, the optimization process is implemented in sequential order: The actuation system layout is first determined through multi-disciplinary topology optimization process, and then the thickness or cross-sectional area of each existent member is optimized under given constraints and boundary conditions. Sample problems are solved to demonstrate the potential capabilities of the presented methodology. The research demonstrates an innovative structural design procedure from a computational perspective and opens new insights into the potential design requirements and characteristics of morphing structures.

The Law of Entropy Increase--A Lab Experiment

ERIC Educational Resources Information Center

Dittrich, William; Drosd, Robert; Minkin, Leonid; Shapovalov, Alexander S.

2016-01-01

The second law of thermodynamics has various formulations. There is the "Clausius formulation," which can be stated in a very intuitive way: "No process is possible whose sole result is the transfer of heat from a cooler to a hotter body." There is also the "Kelvin-Plank principle," which states that "no cyclic…

Heat transfer evaluation in a plasma core reactor

NASA Technical Reports Server (NTRS)

Smith, D. E.; Smith, T. M.; Stoenescu, M. L.

1976-01-01

Numerical evaluations of heat transfer in a fissioning uranium plasma core reactor cavity, operating with seeded hydrogen propellant, was performed. A two-dimensional analysis is based on an assumed flow pattern and cavity wall heat exchange rate. Various iterative schemes were required by the nature of the radiative field and by the solid seed vaporization. Approximate formulations of the radiative heat flux are generally used, due to the complexity of the solution of a rigorously formulated problem. The present work analyzes the sensitivity of the results with respect to approximations of the radiative field, geometry, seed vaporization coefficients and flow pattern. The results present temperature, heat flux, density and optical depth distributions in the reactor cavity, acceptable simplifying assumptions, and iterative schemes. The present calculations, performed in cartesian and spherical coordinates, are applicable to any most general heat transfer problem.

Numerical simulation of tubes-in-tube heat exchanger in a mixed refrigerant Joule-Thomson cryocooler

NASA Astrophysics Data System (ADS)

Damle, R. M.; Ardhapurkar, P. M.; Atrey, M. D.

2017-02-01

Mixed refrigerant Joule-Thomson (MRJT) cryocoolers can produce cryogenic temperatures with high efficiency and low operating pressures. As compared to the high system pressures of around 150-200 bar with nitrogen, the operational pressures with non-azeotropic mixtures (e.g., nitrogen-hydrocarbons) come down to 10-25 bar. With mixtures, the heat transfer in the recuperative heat exchanger takes place in the two-phase region. The simultaneous boiling and condensation of the cold and hot gas streams lead to higher heat transfer coefficients as compared to single phase heat exchange. The two-phase heat transfer in the recuperative heat exchanger drastically affects the performance of a MRJT cryocooler. In this work, a previously reported numerical model for a simple tube-in-tube heat exchanger is extended to a multi tubes-in-tube heat exchanger with a transient formulation. Additionally, the J-T expansion process is also considered to simulate the cooling process of the heat exchanger from ambient temperature conditions. A tubes-in-tube heat exchanger offers more heat transfer area per unit volume resulting in a compact design. Also, the division of flow in multiple tubes reduces the pressure drop in the heat exchanger. Simulations with different mixtures of nitrogen-hydrocarbons are carried out and the numerical results are compared with the experimental data.

Optimization and physicochemical characterization of a cationic lipid-phosphatidylcholine mixed emulsion formulated as a highly efficient vehicle that facilitates adenoviral gene transfer.

PubMed

Kim, Soo-Yeon; Lee, Sang-Jin; Kim, Jin-Ki; Choi, Han-Gon; Lim, Soo-Jeong

2017-01-01

Cationic lipid-based nanoparticles enhance viral gene transfer by forming electrostatic complexes with adenoviral vectors. We recently demonstrated the superior complexation capabilities of 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) emulsion compared with a liposomal counterpart but the cytotoxicity of DOTAP emulsions remained a challenge. The present study is aimed at formulating an emulsion capable of acting as a highly effective viral gene transfer vehicle with reduced cytotoxicity and to physicochemically characterize the structures of virus-emulsion complexes in comparison with virus-liposome complexes when the only difference between emulsions and liposomes was the presence or absence of inner oil core. The emulsion formulation was performed by 1) reducing the content of DOTAP while increasing the content of zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 2) optimizing the oil content. The complexation capability of formulated DOTAP:DMPC mixed emulsions was similar to those of emulsions containing DOTAP alone while displaying significantly lower cytotoxicity. The complexation capabilities of the DOTAP:DMPC mixed emulsion were serum-compatible and were monitored in a variety of cell types, whereas its liposomal counterpart was totally ineffective. Characterization by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and dynamic light scattering studies indicated that the optimized emulsions spontaneously surrounded the virus particles to generate emulsions that encapsulated the viral particles, whereas viral particles merely attached to the surfaces of the counterpart liposomes to form multiviral aggregates. Overall, these studies demonstrated that optimized DOTAP:DMPC mixed emulsions are potentially useful for adenoviral gene delivery due to less cytotoxicity and the unique ability to encapsulate the viral particle, highlighting the importance of nanoparticle formulation.

Optimization and physicochemical characterization of a cationic lipid-phosphatidylcholine mixed emulsion formulated as a highly efficient vehicle that facilitates adenoviral gene transfer

PubMed Central

Kim, Soo-Yeon; Lee, Sang-Jin; Kim, Jin-Ki; Choi, Han-Gon; Lim, Soo-Jeong

2017-01-01

Cationic lipid-based nanoparticles enhance viral gene transfer by forming electrostatic complexes with adenoviral vectors. We recently demonstrated the superior complexation capabilities of 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) emulsion compared with a liposomal counterpart but the cytotoxicity of DOTAP emulsions remained a challenge. The present study is aimed at formulating an emulsion capable of acting as a highly effective viral gene transfer vehicle with reduced cytotoxicity and to physicochemically characterize the structures of virus-emulsion complexes in comparison with virus–liposome complexes when the only difference between emulsions and liposomes was the presence or absence of inner oil core. The emulsion formulation was performed by 1) reducing the content of DOTAP while increasing the content of zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 2) optimizing the oil content. The complexation capability of formulated DOTAP:DMPC mixed emulsions was similar to those of emulsions containing DOTAP alone while displaying significantly lower cytotoxicity. The complexation capabilities of the DOTAP:DMPC mixed emulsion were serum-compatible and were monitored in a variety of cell types, whereas its liposomal counterpart was totally ineffective. Characterization by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and dynamic light scattering studies indicated that the optimized emulsions spontaneously surrounded the virus particles to generate emulsions that encapsulated the viral particles, whereas viral particles merely attached to the surfaces of the counterpart liposomes to form multiviral aggregates. Overall, these studies demonstrated that optimized DOTAP:DMPC mixed emulsions are potentially useful for adenoviral gene delivery due to less cytotoxicity and the unique ability to encapsulate the viral particle, highlighting the importance of nanoparticle formulation. PMID:29070949

Large-Deformation Displacement Transfer Functions for Shape Predictions of Highly Flexible Slender Aerospace Structures

NASA Technical Reports Server (NTRS)

Ko, William L.; Fleischer, Van Tran

2013-01-01

Large deformation displacement transfer functions were formulated for deformed shape predictions of highly flexible slender structures like aircraft wings. In the formulation, the embedded beam (depth wise cross section of structure along the surface strain sensing line) was first evenly discretized into multiple small domains, with surface strain sensing stations located at the domain junctures. Thus, the surface strain (bending strains) variation within each domain could be expressed with linear of nonlinear function. Such piecewise approach enabled piecewise integrations of the embedded beam curvature equations [classical (Eulerian), physical (Lagrangian), and shifted curvature equations] to yield closed form slope and deflection equations in recursive forms.

DERMAL TRANSFER EFFICIENCY OF PESTICIDES FROM TURF GRASS TO DRY AND WETTED PALMS

EPA Science Inventory

This report presents results of a study to determine the transfer of three pesticides commonly used in residential lawn care from turf grass to human skin. Formulation of the insecticides chlorpyrifos and cyfluthrin and the fungicide chlorothalonil were applied to St. Augustin...

Numerical solutions for heat flow in adhesive lap joints

NASA Technical Reports Server (NTRS)

Howell, P. A.; Winfree, William P.

1992-01-01

The present formulation for the modeling of heat transfer in thin, adhesively bonded lap joints precludes difficulties associated with large aspect ratio grids required by standard FEM formulations. This quasi-static formulation also reduces the problem dimensionality (by one), thereby minimizing computational requirements. The solutions obtained are found to be in good agreement with both analytical solutions and solutions from standard FEM programs. The approach is noted to yield a more accurate representation of heat-flux changes between layers due to a disbond.

Protection of the liver against CCl4-induced injury by intramuscular electrotransfer of a kallistatin-encoding plasmid.

PubMed

Diao, Yong; Zhao, Xiao-Feng; Lin, Jun-Sheng; Wang, Qi-Zhao; Xu, Rui-An

2011-01-07

To investigate the effect of transgenic expression of kallistatin (Kal) on carbon tetrachloride (CCl(4))-induced liver injury by intramuscular (im) electrotransfer of a Kal-encoding plasmid formulated with poly-L-glutamate (PLG). The pKal plasmid encoding Kal gene was formulated with PLG and electrotransferred into mice skeletal muscle before the administration of CCl4. The expression level of Kal was measured. The serum biomarker levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), malonyldialdehyde (MDA), and tumor necrosis factor (TNF)-α were monitored. The extent of CCl4-induced liver injury was analyzed histopathologically. The transgene of Kal was sufficiently expressed after an im injection of plasmid formulated with PLG followed by electroporation. In the Kal gene-transferred mice, protection against CCl4-induced liver injury was reflected by significantly decreased serum ALT, AST, MDA and TNF-α levels compared to those in control mice (P<0.01 to 0.05 in a dose-dependent manner). Histological observations also revealed that hepatocyte necrosis, hemorrhage, vacuolar change and hydropic degeneration were apparent in mice after CCl4 administration. In contrast, the damage was markedly attenuated in the Kal gene-transferred mice. The expression of hepatic fibrogenesis marker transforming growth factor-β1 was also reduced in the pKal transferred mice. Intramuscular electrotransfer of plasmid pKal which was formulated with PLG significantly alleviated the CCl4-induced oxidative stress and inflammatory response, and reduced the liver damage in a mouse model.

Status and trends monitoring of the mainstem Columbia River: sample frame development and review of programs relevant to the development of an integrated approach to monitoring

USGS Publications Warehouse

Counihan, Timothy D.; Hardiman, Jill M.; Waste, Stephen

2013-01-01

Implementing an Integrated Status and Trends Monitoring program (ISTM) for the mainstem Columbia River will help identify trends in important natural resources and help us understand the long-term collective effects of management actions. In this report, we present progress towards the completion of a stepwise process that will facilitate the development of an ISTM for the mainstem Columbia River. We discuss planning and regulatory documents that can be used to identify monitoring goals and objectives and present existing monitoring and research activities that should be considered as the development of a Columbia River ISTM proceeds. We also report progress towards the development of sample frames for the Columbia and Snake Rivers and their floodplains. The sample frames were formulated using Digital Elevation Models (DEM’s) of the river channel and upland areas and a Generalized Random-Tessellation Stratified (GRTS) algorithm for an area based resource to generate “master sample(s).” Working with the Pacific Northwest Aquatic Monitoring Partnership (PNAMP) we facilitated the transfer of the sample frames to the PNAMP “Monitoring Sample Designer” tool. We then discuss aspects of response and survey designs as they pertain to the formulation of a mainstem Columbia River ISTM. As efforts to formulate an ISTM for the mainstem Columbia River proceed, practitioners should utilize the extensive literature describing the planning and implementation of fish and wildlife mitigation and recovery efforts in the Columbia River Basin. While we make progress towards establishing an ISTM framework, considerable work needs to be done to formulate an ISTM program for the mainstem Columbia River. Long-term monitoring programs have been established for other large rivers systems; scientists that have experience planning, implementing, and maintaining large river monitoring efforts such as those in the Colorado, Illinois, and Mississippi Rivers should be consulted and involved as efforts proceed.

DERMAL TRANSFER EFFICIENCY OF PESTICIDES FROM NEW AND USED CUT-PILE CARPET TO DRY AND WETTED PALMS

EPA Science Inventory

This report presents results of a study to determine the transfer efficiencies from carpet to human skin of four pesticides commonly used for residential indoor insect control. Formulations of the insecticides chlorpyrifos, pyrethrin I and piperonyl butoxide were applied to new...

Improved Displacement Transfer Functions for Structure Deformed Shape Predictions Using Discretely Distributed Surface Strains

NASA Technical Reports Server (NTRS)

Ko, William L.; Fleischer, Van Tran

2012-01-01

In the formulations of earlier Displacement Transfer Functions for structure shape predictions, the surface strain distributions, along a strain-sensing line, were represented with piecewise linear functions. To improve the shape-prediction accuracies, Improved Displacement Transfer Functions were formulated using piecewise nonlinear strain representations. Through discretization of an embedded beam (depth-wise cross section of a structure along a strain-sensing line) into multiple small domains, piecewise nonlinear functions were used to describe the surface strain distributions along the discretized embedded beam. Such piecewise approach enabled the piecewise integrations of the embedded beam curvature equations to yield slope and deflection equations in recursive forms. The resulting Improved Displacement Transfer Functions, written in summation forms, were expressed in terms of beam geometrical parameters and surface strains along the strain-sensing line. By feeding the surface strains into the Improved Displacement Transfer Functions, structural deflections could be calculated at multiple points for mapping out the overall structural deformed shapes for visual display. The shape-prediction accuracies of the Improved Displacement Transfer Functions were then examined in view of finite-element-calculated deflections using different tapered cantilever tubular beams. It was found that by using the piecewise nonlinear strain representations, the shape-prediction accuracies could be greatly improved, especially for highly-tapered cantilever tubular beams.

Solid-perforated panel layout optimization by topology optimization based on unified transfer matrix.

PubMed

Kim, Yoon Jae; Kim, Yoon Young

2010-10-01

This paper presents a numerical method for the optimization of the sequencing of solid panels, perforated panels and air gaps and their respective thickness for maximizing sound transmission loss and/or absorption. For the optimization, a method based on the topology optimization formulation is proposed. It is difficult to employ only the commonly-used material interpolation technique because the involved layers exhibit fundamentally different acoustic behavior. Thus, an optimization method formulation using a so-called unified transfer matrix is newly proposed. The key idea is to form elements of the transfer matrix such that interpolated elements by the layer design variables can be those of air, perforated and solid panel layers. The problem related to the interpolation is addressed and bench mark-type problems such as sound transmission or absorption maximization problems are solved to check the efficiency of the developed method.

Polycation nanostructured lipid carrier, a novel nonviral vector constructed with triolein for efficient gene delivery.

PubMed

Zhang, Zhiwen; Sha, Xianyi; Shen, Anle; Wang, Yongzhong; Sun, Zhaogui; Gu, Zheng; Fang, Xiaoling

2008-06-06

A novel nonviral gene transfer vector was developed by modifying nanostructured lipid carrier (NLC) with cetylated polyethylenimine (PEI). Polycation nanostructured lipid carrier (PNLC) was prepared using the emulsion-solvent evaporation method. Its in vitro gene transfer properties were evaluated in the human lung adenocarcinoma cell line SPC-A1 and Chinese Hamster Ovary (CHO) cells. Enhanced transfection efficiency of PNLC was observed after the addition of triolein to the PNLC formulation and the transfection efficiency of the optimized PNLC was comparable to that of Lipofectamine 2000. In the presence of 10% serum the transfection efficiency of the optimal PNLC was not significantly changed in either cell line, whereas that of Lipofectamine 2000 was greatly decreased in both. Thus, PNLC is an effective nonviral gene transfer vector and the gene delivery activity of PNLC was enhanced after triolein was included into the PNLC formulation.

Equivalent isotropic scattering formulation for transient short-pulse radiative transfer in anisotropic scattering planar media.

PubMed

Guo, Z; Kumar, S

2000-08-20

An isotropic scaling formulation is evaluated for transient radiative transfer in a one-dimensional planar slab subject to collimated and/or diffuse irradiation. The Monte Carlo method is used to implement the equivalent scattering and exact simulations of the transient short-pulse radiation transport through forward and backward anisotropic scattering planar media. The scaled equivalent isotropic scattering results are compared with predictions of anisotropic scattering in various problems. It is found that the equivalent isotropic scaling law is not appropriate for backward-scattering media in transient radiative transfer. Even for an optically diffuse medium, the differences in temporal transmittance and reflectance profiles between predictions of backward anisotropic scattering and equivalent isotropic scattering are large. Additionally, for both forward and backward anisotropic scattering media, the transient equivalent isotropic results are strongly affected by the change of photon flight time, owing to the change of flight direction associated with the isotropic scaling technique.

Design principles of water sensitive in settlement area on the river banks

NASA Astrophysics Data System (ADS)

Ryanti, E.; Hasriyanti, N.; Utami, W. D.

2018-03-01

This research will formulate the principle of designing settlement area of Kapuas River Pontianak with the approach of water sensitive concept of urban design (WSUD) the densely populated settlement area. By using a case study the approach that is a dense settlement area located on the banks of the river with literature study techniques to formulate the aspects considered and components that are set in the design, descriptive analysis with the rationalistic paradigm for identification characteristics of the settlement in the river banks areas with consideration of WSUD elements and formulate the principles of designing water-sensitive settlement areas. This research is important to do because the problems related to the water management system in the existing riverside settlement in Pontianak has not been maximal to do. So the primary of this research contains several objectives that will be achieved that is identifying the characteristics of riverside settlement area based on consideration of design aspects of the area that are sensitive to water and the principle of designing the area so that the existing problem structure will be formulated in relation to the community’s need for infrastructure in settlement environment and formulate and develop appropriate technology guidelines for integrated water management systems in riverside settlement areas and design techniques for water-sensitive settlements (WSUD).

Linear and nonlinear dynamic analysis of redundant load path bearingless rotor systems

NASA Technical Reports Server (NTRS)

Murthy, V. R.; Shultz, Louis A.

1994-01-01

The goal of this research is to develop the transfer matrix method to treat nonlinear autonomous boundary value problems with multiple branches. The application is the complete nonlinear aeroelastic analysis of multiple-branched rotor blades. Once the development is complete, it can be incorporated into the existing transfer matrix analyses. There are several difficulties to be overcome in reaching this objective. The conventional transfer matrix method is limited in that it is applicable only to linear branch chain-like structures, but consideration of multiple branch modeling is important for bearingless rotors. Also, hingeless and bearingless rotor blade dynamic characteristics (particularly their aeroelasticity problems) are inherently nonlinear. The nonlinear equations of motion and the multiple-branched boundary value problem are treated together using a direct transfer matrix method. First, the formulation is applied to a nonlinear single-branch blade to validate the nonlinear portion of the formulation. The nonlinear system of equations is iteratively solved using a form of Newton-Raphson iteration scheme developed for differential equations of continuous systems. The formulation is then applied to determine the nonlinear steady state trim and aeroelastic stability of a rotor blade in hover with two branches at the root. A comprehensive computer program is developed and is used to obtain numerical results for the (1) free vibration, (2) nonlinearly deformed steady state, (3) free vibration about the nonlinearly deformed steady state, and (4) aeroelastic stability tasks. The numerical results obtained by the present method agree with results from other methods.

Multiphysics Analysis of a Solid-Core Nuclear Thermal Engine Thrust Chamber

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Canabal, Francisco; Cheng, Gary; Chen, Yen-Sen

2006-01-01

The objective of this effort is to develop an efficient and accurate thermo-fluid computational methodology to predict environments for a hypothetical solid-core, nuclear thermal engine thrust chamber. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics methodology. Formulations for heat transfer in solids and porous media were implemented and anchored. A two-pronged approach was employed in this effort: A detailed thermo-fluid analysis on a multi-channel flow element for mid-section corrosion investigation; and a global modeling of the thrust chamber to understand the effect of hydrogen dissociation and recombination on heat transfer and thrust performance. The formulations and preliminary results on both aspects are presented.

Electron distribution function in a plasma generated by fission fragments

NASA Technical Reports Server (NTRS)

Hassan, H. A.; Deese, J. E.

1976-01-01

A Boltzmann equation formulation is presented for the determination of the electron distribution function in a plasma generated by fission fragments. The formulation takes into consideration ambipolar diffusion, elastic and inelastic collisions, recombination and ionization, and allows for the fact that the primary electrons are not monoenergetic. Calculations for He in a tube coated with fissionable material shows that, over a wide pressure and neutron flux range, the distribution function is non-Maxwellian, but the electrons are essentially thermal. Moreover, about a third of the energy of the primary electrons is transferred into the inelastic levels of He. This fraction of energy transfer is almost independent of pressure and neutron flux.

Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids

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

Raade, Justin; Roark, Thomas; Vaughn, John

2013-07-22

Concentrating solar power (CSP) facilities are comprised of many miles of fluid-filled pipes arranged in large grids with reflective mirrors used to capture radiation from the sun. Solar radiation heats the fluid which is used to produce steam necessary to power large electricity generation turbines. Currently, organic, oil-based fluid in the pipes has a maximum temperature threshold of 400 °C, allowing for the production of electricity at approximately 15 cents per kilowatt hour. The DOE hopes to foster the development of an advanced heat transfer fluid that can operate within higher temperature ranges. The new heat transfer fluid, when usedmore » with other advanced technologies, could significantly decrease solar electricity cost. Lower costs would make solar thermal electricity competitive with gas and coal and would offer a clean, renewable source of energy. Molten salts exhibit many desirable heat transfer qualities within the range of the project objectives. Halotechnics developed advanced heat transfer fluids (HTFs) for application in solar thermal power generation. This project focused on complex mixtures of inorganic salts that exhibited a high thermal stability, a low melting point, and other favorable characteristics. A high-throughput combinatorial research and development program was conducted in order to achieve the project objective. Over 19,000 candidate formulations were screened. The workflow developed to screen various chemical systems to discover salt formulations led to mixtures suitable for use as HTFs in both parabolic trough and heliostat CSP plants. Furthermore, salt mixtures which will not interfere with fertilizer based nitrates were discovered. In addition for use in CSP, the discovered salt mixtures can be applied to electricity storage, heat treatment of alloys and other industrial processes.« less

Formulation of a dynamic analysis method for a generic family of hoop-mast antenna systems

NASA Technical Reports Server (NTRS)

Gabriele, A.; Loewy, R.

1981-01-01

Analytical studies of mast-cable-hoop-membrane type antennas were conducted using a transfer matrix numerical analysis approach. This method, by virtue of its specialization and the inherently easy compartmentalization of the formulation and numerical procedures, can be significantly more efficient in computer time required and in the time needed to review and interpret the results.

Fundamental Studies Connected with Electrochemical Energy Storage

NASA Technical Reports Server (NTRS)

Buck, E.; Sen, R.

1974-01-01

Papers are presented which deal with electrochemical research activities. Emphasis is placed on electrochemical energy storage devices. Topics discussed include: adsorption of dendrite inhibitors on zinc; proton discharge process; electron and protron transfer; quantum mechanical formulation of electron transfer rates; and theory of electrochemical kinetics in terms of two models of activation; thermal and electrostatic.

“Transference Ratios” to Predict Total Oxidized Sulfur and Nitrogen Deposition – Part I, Monitoring Results

EPA Science Inventory

Use of model-predicted “transference ratios” is currently under consideration by the US EPA in the formulation of a Secondary National Ambient Air Quality Standard for oxidized nitrogen and oxidized sulfur. This term is an empirical parameter defined for oxidized sulfur (TS)as th...

Predicting plant protein subcellular multi-localization by Chou's PseAAC formulation based multi-label homolog knowledge transfer learning.

PubMed

Mei, Suyu

2012-10-07

Recent years have witnessed much progress in computational modeling for protein subcellular localization. However, there are far few computational models for predicting plant protein subcellular multi-localization. In this paper, we propose a multi-label multi-kernel transfer learning model for predicting multiple subcellular locations of plant proteins (MLMK-TLM). The method proposes a multi-label confusion matrix and adapts one-against-all multi-class probabilistic outputs to multi-label learning scenario, based on which we further extend our published work MK-TLM (multi-kernel transfer learning based on Chou's PseAAC formulation for protein submitochondria localization) for plant protein subcellular multi-localization. By proper homolog knowledge transfer, MLMK-TLM is applicable to novel plant protein subcellular localization in multi-label learning scenario. The experiments on plant protein benchmark dataset show that MLMK-TLM outperforms the baseline model. Unlike the existing models, MLMK-TLM also reports its misleading tendency, which is important for comprehensive survey of model's multi-labeling performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Numerical Modeling of Saturated Boiling in a Heated Tube

NASA Technical Reports Server (NTRS)

Majumdar, Alok; LeClair, Andre; Hartwig, Jason

2017-01-01

This paper describes a mathematical formulation and numerical solution of boiling in a heated tube. The mathematical formulation involves a discretization of the tube into a flow network consisting of fluid nodes and branches and a thermal network consisting of solid nodes and conductors. In the fluid network, the mass, momentum and energy conservation equations are solved and in the thermal network, the energy conservation equation of solids is solved. A pressure-based, finite-volume formulation has been used to solve the equations in the fluid network. The system of equations is solved by a hybrid numerical scheme which solves the mass and momentum conservation equations by a simultaneous Newton-Raphson method and the energy conservation equation by a successive substitution method. The fluid network and thermal network are coupled through heat transfer between the solid and fluid nodes which is computed by Chen's correlation of saturated boiling heat transfer. The computer model is developed using the Generalized Fluid System Simulation Program and the numerical predictions are compared with test data.

Continuum mechanics and thermodynamics in the Hamilton and the Godunov-type formulations

NASA Astrophysics Data System (ADS)

Peshkov, Ilya; Pavelka, Michal; Romenski, Evgeniy; Grmela, Miroslav

2018-01-01

Continuum mechanics with dislocations, with the Cattaneo-type heat conduction, with mass transfer, and with electromagnetic fields is put into the Hamiltonian form and into the form of the Godunov-type system of the first-order, symmetric hyperbolic partial differential equations (SHTC equations). The compatibility with thermodynamics of the time reversible part of the governing equations is mathematically expressed in the former formulation as degeneracy of the Hamiltonian structure and in the latter formulation as the existence of a companion conservation law. In both formulations the time irreversible part represents gradient dynamics. The Godunov-type formulation brings the mathematical rigor (the local well posedness of the Cauchy initial value problem) and the possibility to discretize while keeping the physical content of the governing equations (the Godunov finite volume discretization).

Effects of unsteady free stream velocity and free stream turbulence on stagnation point heat transfer

NASA Technical Reports Server (NTRS)

Gorla, R. S. R.

1984-01-01

The combined effects of transient free stream velocity and free stream turbulence on heat transfer at a stagnation point over a cylinder situated in a crossflow are studied. An eddy diffusivity model was formulated and the governing momentum and energy equations are integrated by means of the steepest descent method. The numerical results for the wall shear stress and heat transfer rate are correlated by a turbulence parameter. The wall friction and heat transfer rate increase with increasing free stream turbulence intensity.

Microclimatic modeling of the desert in the United Arab Emirates

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

Khalil, A.K.; Abdrabboh, M.A.; Kamel, K.A.

1996-10-01

The present study is concerned with the prediction of the weather parameters in the microclimate layer (less than 2 m above the ground surface) in the desert and sparsely vegetated areas in the United Arab Emirates. A survey was made of the weather data in these regions including solar radiation, wind speed, screen temperatures and relative humidity. Additionally, wind speed data were obtained at heights below two meters and surface albedo was recorded for various soil and vegetation conditions. A survey was also carried out for the different plant species in various areas of the U.A.E. Data on soil andmore » surface temperature were then analyzed. An energy balance model was formulated including incident short- and long-wave length radiation between earth and sky, convective heat transfer to/from earth surface, surface reflection of solar radiation and soil/plant evapotranspiration. An explicit one dimensional finite difference scheme was adapted to solve the resulting algebraic finite difference equations. The equation for surface nodes included thermal radiation as well as convection effects. The heat transfer coefficient was evaluated on the basis of wind speed and surface roughness at the site where the energy balance was set. Theoretical predictions of air and soil temperatures were accordingly compared to experimental measurements in selected sites, where reasonable agreements were observed.« less

Resin transfer molding speeds composite making

NASA Astrophysics Data System (ADS)

Valenti, Michael

1992-11-01

Fabrication resin transfer molding (RTM) composite parts for different industrial applications is discussed. These applications include composite aerospace parts, sports car components, and high performance sporting equipment. It is pointed out that RTM parts are lighter than metals and can be formulated to have superior durability. But like all composite parts, they are expensive and are made in limited runs.

The Potential Transfer of Industrial Skills from Defense to Nondefense Industries. Volume II, Technical Appendix.

ERIC Educational Resources Information Center

California State Dept. of Employment, Sacramento.

This study of skill transferability between missile production and nondefense industries provides the necessary data to help formulate retraining and other programs designed to help workers adjust to cutbacks in defense spending. This technical appendix to the project report contains the data upon which the report's conclusions are based. The…

Modeling donor/acceptor interactions: Combined roles of theory and computation

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

Newton, M.D.

2000-03-05

An extended superexchange model for electron transfer (ET) matrix elements (H{sub DA}) has been formulated as a superposition of McConnell-type pathways and implemented by combined use of configuration interaction wave functions (obtained using the INDO/s model of Zerner and co-workers) and the generalized Muliken-Hush formulation of charge-localized diabatic states. Applications are made for et (and hold transfer) in several donor/bridge/acceptor radical anion (and cation) systems, (DBA){sup {+-}}, allowing detailed comparison with experimental H{sub DA} estimates. For the case of oligo phenylene ethynylene (OPE) bridges, the role of {pi} and {sigma} electronic manifolds for different distributions of phenylene torsion angles ismore » analyzed in detail.« less

Structural characterization of a new lipid/DNA complex showing a selective transfection efficiency in ovarian cancer cells

NASA Astrophysics Data System (ADS)

Caracciolo, G.; Pozzi, D.; Caminiti, R.; Congiu Castellano, A.

2003-04-01

We investigated, for the first time, by using Energy Dispersive X-ray Diffraction, the structure of a new ternary cationic liposome formulated with dioleoyl trimethylammonium propane (DOTAP), 1,2-dioleoyl-3-phosphatidylethanolamine (DOPE) and cholesterol (Chol) (DDC) which has been recently found to have a selective high gene transfer ability in ovarian cancer cells. Our structural results provide a further experimental support to the widely accepted statement that there is not a simple and direct correlation between structure and transfection efficiency and that the factors controlling cationic lipid/DNA (CL-DNA) complexes-mediated gene transfer depend not only on the formulations of the cationic liposomes and their thermodynamic phase, but also significantly on the cell properties.

The electron Boltzmann equation in a plasma generated by fission fragments

NASA Technical Reports Server (NTRS)

Hassan, H. A.; Deese, J. E.

1976-01-01

A Boltzmann equation formulation is presented for the determination of the electron distribution function in a plasma generated by fission fragments. The formulation takes into consideration ambipolar diffusion, elastic and inelastic collisions, recombination and ionization, and allows for the fact that the primary electrons are not monoenergetic. Calculations for He in a tube coated with fissionable material show that, over a wide pressure and neutron flux range, the distribution function is non-Maxwellian, but the electrons are essentially thermal. Moreover, about a third of the energy of the primary electrons is transferred into the inelastic levels of He. This fraction of energy transfer is almost independent of pressure and neutron flux but increases sharply in the presence of a sustainer electric field.

Solution of the 2-D steady-state radiative transfer equation in participating media with specular reflections using SUPG and DG finite elements

NASA Astrophysics Data System (ADS)

Le Hardy, D.; Favennec, Y.; Rousseau, B.

2016-08-01

The 2D radiative transfer equation coupled with specular reflection boundary conditions is solved using finite element schemes. Both Discontinuous Galerkin and Streamline-Upwind Petrov-Galerkin variational formulations are fully developed. These two schemes are validated step-by-step for all involved operators (transport, scattering, reflection) using analytical formulations. Numerical comparisons of the two schemes, in terms of convergence rate, reveal that the quadratic SUPG scheme proves efficient for solving such problems. This comparison constitutes the main issue of the paper. Moreover, the solution process is accelerated using block SOR-type iterative methods, for which the determination of the optimal parameter is found in a very cheap way.

Nonlinear Transient Problems Using Structure Compatible Heat Transfer Code

NASA Technical Reports Server (NTRS)

Hou, Gene

2000-01-01

The report documents the recent effort to enhance a transient linear heat transfer code so as to solve nonlinear problems. The linear heat transfer code was originally developed by Dr. Kim Bey of NASA Largely and called the Structure-Compatible Heat Transfer (SCHT) code. The report includes four parts. The first part outlines the formulation of the heat transfer problem of concern. The second and the third parts give detailed procedures to construct the nonlinear finite element equations and the required Jacobian matrices for the nonlinear iterative method, Newton-Raphson method. The final part summarizes the results of the numerical experiments on the newly enhanced SCHT code.

Distribution of Particles, Small Molecules and Polymeric Formulation Excipients in the Suprachoroidal Space after Microneedle Injection

PubMed Central

Chiang, Bryce; Venugopal, Nitin; Edelhauser, Henry F.; Prausnitz, Mark R.

2016-01-01

The purpose of this work was to determine the effect of injection volume, formulation composition, and time on circumferential spread of particles, small molecules and polymeric formulation excipients in the suprachoroidal space (SCS) after microneedle injection into New Zealand White rabbit eyes ex vivo and in vivo. Microneedle injections of 25–150 μL Hank’s Balanced Salt Solution (HBSS) containing 0.2 μm red-fluorescent particles and a model small molecule (fluorescein) were performed in rabbit eyes ex vivo, and visualized via flat mount. Particles with diameters of 0.02 – 2 μm were co-injected into SCS in vivo with fluorescein or a polymeric formulation excipient: fluorescein isothiocyanate (FITC)-labeled Discovisc or FITC-labeled carboxymethyl cellulose (CMC). Fluorescent fundus images were acquired over time to determine area of particle, fluorescein and polymeric formulation excipient spread, as well as their co-localization. We found that fluorescein covered a significantly larger area than co-injected particles when suspended in HBSS, and that this difference was present from 3 min post-injection onwards. We further showed that there was no difference in initial area covered by FITC-Discovisc and particles; the transport time (i.e., the time until the FITC-Discovisc and particle area began dissociating) was 2 d. There was also no difference in initial area covered by FITC-CMC and particles; the transport time in FITC-CMC was 4 d. We also found that particle size (20 nm – 2 μm) had no effect on spreading area when delivered in HBSS or Discovisc. We conclude that (i) the area of particle spread in SCS during injection generally increased with increasing injection volume, was unaffected by particle size and was significantly less than the area of fluorescein spread, (ii) particles suspended in low-viscosity HBSS formulation were entrapped in the SCS after injection, whereas fluorescein was not and (iii) particles co-injected with viscous polymeric formulation excipients co-localized near the site of injection in the SCS, continued to co-localize while spreading over larger areas for 2 – 4 days, and then no longer co-localized as the polymeric formulation excipients were cleared within 1 – 3 weeks and the particles remained largely in place. These data suggest that particles encounter greater barriers to flow in SCS compared to molecules and that co-localization of particles and polymeric formulation excipients allow spreading over larger areas of the SCS until the particles and excipients dissociate. PMID:27742547

Distribution of particles, small molecules and polymeric formulation excipients in the suprachoroidal space after microneedle injection.

PubMed

Chiang, Bryce; Venugopal, Nitin; Edelhauser, Henry F; Prausnitz, Mark R

2016-12-01

The purpose of this work was to determine the effect of injection volume, formulation composition, and time on circumferential spread of particles, small molecules, and polymeric formulation excipients in the suprachoroidal space (SCS) after microneedle injection into New Zealand White rabbit eyes ex vivo and in vivo. Microneedle injections of 25-150 μL Hank's Balanced Salt Solution (HBSS) containing 0.2 μm red-fluorescent particles and a model small molecule (fluorescein) were performed in rabbit eyes ex vivo, and visualized via flat mount. Particles with diameters of 0.02-2 μm were co-injected into SCS in vivo with fluorescein or a polymeric formulation excipient: fluorescein isothiocyanate (FITC)-labeled Discovisc or FITC-labeled carboxymethyl cellulose (CMC). Fluorescent fundus images were acquired over time to determine area of particle, fluorescein, and polymeric formulation excipient spread, as well as their co-localization. We found that fluorescein covered a significantly larger area than co-injected particles when suspended in HBSS, and that this difference was present from 3 min post-injection onwards. We further showed that there was no difference in initial area covered by FITC-Discovisc and particles; the transport time (i.e., the time until the FITC-Discovisc and particle area began dissociating) was 2 d. There was also no difference in initial area covered by FITC-CMC and particles; the transport time in FITC-CMC was 4 d. We also found that particle size (20 nm-2 μm) had no effect on spreading area when delivered in HBSS or Discovisc. We conclude that (i) the area of particle spread in SCS during injection generally increased with increasing injection volume, was unaffected by particle size, and was significantly less than the area of fluorescein spread, (ii) particles suspended in low-viscosity HBSS formulation were entrapped in the SCS after injection, whereas fluorescein was not and (iii) particles co-injected with viscous polymeric formulation excipients co-localized near the site of injection in the SCS, continued to co-localize while spreading over larger areas for 2-4 days, and then no longer co-localized as the polymeric formulation excipients were cleared within 1-3 weeks and the particles remained largely in place. These data suggest that particles encounter greater barriers to flow in SCS compared to molecules and that co-localization of particles and polymeric formulation excipients allows spreading over larger areas of the SCS until the particles and excipients dissociate. Copyright © 2016 Elsevier Ltd. All rights reserved.

New electron-energy transfer rates for vibrational excitation of O2

NASA Astrophysics Data System (ADS)

Jones, D. B.; Campbell, L.; Bottema, M. J.; Brunger, M. J.

2003-09-01

We report on our computation of electron-energy transfer rates for vibrational excitation of O2. This work was necessitated by inadequacies in the electron-impact cross section databases employed in previous studies and, in one case, an inaccurate approximate formulation to the rate equation. Both these inadequacies led to incorrect energy transfer rates being published in the literature. We also demonstrate the importance of using cross sections that encompass an energy range that is extended enough to appropriately describe the environment under investigation.

Effect of energy transfer from atomic electron shell to an α particle emitted by decaying nucleus

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

Igashov, S. Yu., E-mail: igashov@theor.mephi.ru; Tchuvil’sky, Yu. M.

2016-12-15

The process of energy transfer from the electron shell of an atom to an α particle propagating through the shell is formulated mathematically. Using the decay of the {sup 226}Ra nucleus as an example, it is demonstrated that this phenomenon increases the α-decay intensity in contrast with other known effects of similar type. Moreover, the α decay of the nucleus is more strongly affected by the energy transfer than by all other effects taken together.

Energy transfer dynamics and kinetics of elementary processes (promoted) by gas-phase CO2 -N2 collisions: Selectivity control by the anisotropy of the interaction.

PubMed

Lombardi, Andrea; Pirani, Fernando; Laganà, Antonio; Bartolomei, Massimiliano

2016-06-15

In this work, we exploit a new formulation of the potential energy and of the related computational procedures, which embodies the coupling between the intra and intermolecular components, to characterize possible propensities of the collision dynamics in energy transfer processes of interest for simulation and control of phenomena occurring in a variety of equilibrium and nonequilibrium environments. The investigation reported in the paper focuses on the prototype CO2 -N2 system, whose intramolecular component of the interaction is modeled in terms of a many body expansion while the intermolecular component is modeled in terms of a recently developed bonds-as-interacting-molecular-centers' approach. The main advantage of this formulation of the potential energy surface is that of being (a) truly full dimensional (i.e., all the variations of the coordinates associated with the molecular vibrations and rotations on the geometrical and electronic structure of the monomers, are explicitly taken into account without freezing any bonds or angles), (b) more flexible than other usual formulations of the interaction and (c) well suited for fitting procedures better adhering to accurate ab initio data and sensitive to experimental arrangement dependent information. Specific attention has been given to the fact that a variation of vibrational and rotational energy has a higher (both qualitative and quantitative) impact on the energy transfer when a more accurate formulation of the intermolecular interaction (with respect to that obtained when using rigid monomers) is adopted. This makes the potential energy surface better suited for the kinetic modeling of gaseous mixtures in plasma, combustion and atmospheric chemistry computational applications. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Fluctuating volume-current formulation of electromagnetic fluctuations in inhomogeneous media: Incandescence and luminescence in arbitrary geometries

NASA Astrophysics Data System (ADS)

Polimeridis, Athanasios G.; Reid, M. T. H.; Jin, Weiliang; Johnson, Steven G.; White, Jacob K.; Rodriguez, Alejandro W.

2015-10-01

We describe a fluctuating volume-current formulation of electromagnetic fluctuations that extends our recent work on heat exchange and Casimir interactions between arbitrarily shaped homogeneous bodies [A. W. Rodriguez, M. T. H. Reid, and S. G. Johnson, Phys. Rev. B 88, 054305 (2013), 10.1103/PhysRevB.88.054305] to situations involving incandescence and luminescence problems, including thermal radiation, heat transfer, Casimir forces, spontaneous emission, fluorescence, and Raman scattering, in inhomogeneous media. Unlike previous scattering formulations based on field and/or surface unknowns, our work exploits powerful techniques from the volume-integral equation (VIE) method, in which electromagnetic scattering is described in terms of volumetric, current unknowns throughout the bodies. The resulting trace formulas (boxed equations) involve products of well-studied VIE matrices and describe power and momentum transfer between objects with spatially varying material properties and fluctuation characteristics. We demonstrate that thanks to the low-rank properties of the associated matrices, these formulas are susceptible to fast-trace computations based on iterative methods, making practical calculations tractable. We apply our techniques to study thermal radiation, heat transfer, and fluorescence in complicated geometries, checking our method against established techniques best suited for homogeneous bodies as well as applying it to obtain predictions of radiation from complex bodies with spatially varying permittivities and/or temperature profiles.

Propagation of eigenmodes and transfer functions in waveguide WDM structures

NASA Astrophysics Data System (ADS)

Mashkov, Vladimir A.; Francoeur, S.; Geuss, U.; Neiser, K.; Temkin, Henryk

1998-02-01

A method of propagation functions and transfer amplitudes suitable for the design of integrated optical circuits is presented. The method is based on vectorial formulation of electrodynamics: the distributions and propagation of electromagnetic fields in optical circuits is described by equivalent surface sources. This approach permits a division of complex optical waveguide structures into sets of primitive blocks and to separately calculate the transfer function and the transfer amplitude for each block. The transfer amplitude of the entire optical system is represented by a convolution of transfer amplitudes of its primitive blocks. The eigenvalues and eigenfunctions of arbitrary waveguide structure are obtained in the WKB approximation and compared with other methods. The general approach is illustrated with the transfer amplitude calculations for Dragone's star coupler and router.

Turbine Vane External Heat Transfer. Volume 1: Analytical and Experimental Evaluation of Surface Heat Transfer Distributions with Leading Edge Showerhead Film Cooling

NASA Technical Reports Server (NTRS)

Turner, E. R.; Wilson, M. D.; Hylton, L. D.; Kaufman, R. M.

1985-01-01

Progress in predictive design capabilities for external heat transfer to turbine vanes was summarized. A two dimensional linear cascade (previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils) was used to examine the effect of leading edge shower head film cooling on downstream heat transfer. The data were used to develop and evaluate analytical models. Modifications to the two dimensional boundary layer model are described. The results were used to formulate and test an effective viscosity model capable of predicting heat transfer phenomena downstream of the leading edge film cooling array on both the suction and pressure surfaces, with and without mass injection.

Optimal transfers between libration-point orbits in the elliptic restricted three-body problem

NASA Astrophysics Data System (ADS)

Hiday, Lisa Ann

1992-09-01

A strategy is formulated to design optimal impulsive transfers between three-dimensional libration-point orbits in the vicinity of the interior L(1) libration point of the Sun-Earth/Moon barycenter system. Two methods of constructing nominal transfers, for which the fuel cost is to be minimized, are developed; both inferior and superior transfers between two halo orbits are considered. The necessary conditions for an optimal transfer trajectory are stated in terms of the primer vector. The adjoint equation relating reference and perturbed trajectories in this formulation of the elliptic restricted three-body problem is shown to be distinctly different from that obtained in the analysis of trajectories in the two-body problem. Criteria are established whereby the cost on a nominal transfer can be improved by the addition of an interior impulse or by the implementation of coastal arcs in the initial and final orbits. The necessary conditions for the local optimality of a time-fixed transfer trajectory possessing additional impulses are satisfied by requiring continuity of the Hamiltonian and the derivative of the primer vector at all interior impulses. The optimality of a time-free transfer containing coastal arcs is surmised by examination of the slopes at the endpoints of a plot of the magnitude of the primer vector over the duration of the transfer path. If the initial and final slopes of the primer magnitude are zero, the transfer trajectory is optimal; otherwise, the execution of coasts is warranted. The position and timing of each interior impulse applied to a time-fixed transfer as well as the direction and length of coastal periods implemented on a time-free transfer are specified by the unconstrained minimization of the appropriate variation in cost utilizing a multivariable search technique. Although optimal solutions in some instances are elusive, the time-fixed and time-free optimization algorithms prove to be very successful in diminishing costs on nominal transfer trajectories. The inclusion of coastal arcs on time-free superior and inferior transfers results in significant modification of the transfer time of flight caused by shifts in departure and arrival locations on the halo orbits.

A reduced-order integral formulation to account for the finite size effect of isotropic square panels using the transfer matrix method.

PubMed

Bonfiglio, Paolo; Pompoli, Francesco; Lionti, Riccardo

2016-04-01

The transfer matrix method is a well-established prediction tool for the simulation of sound transmission loss and the sound absorption coefficient of flat multilayer systems. Much research has been dedicated to enhancing the accuracy of the method by introducing a finite size effect of the structure to be simulated. The aim of this paper is to present a reduced-order integral formulation to predict radiation efficiency and radiation impedance for a panel with equal lateral dimensions. The results are presented and discussed for different materials in terms of radiation efficiency, sound transmission loss, and the sound absorption coefficient. Finally, the application of the proposed methodology for rectangular multilayer systems is also investigated and validated against experimental data.

Multidisciplinary analysis of actively controlled large flexible spacecraft

NASA Technical Reports Server (NTRS)

Cooper, Paul A.; Young, John W.; Sutter, Thomas R.

1986-01-01

The control of Flexible Structures (COFS) program has supported the development of an analysis capability at the Langley Research Center called the Integrated Multidisciplinary Analysis Tool (IMAT) which provides an efficient data storage and transfer capability among commercial computer codes to aid in the dynamic analysis of actively controlled structures. IMAT is a system of computer programs which transfers Computer-Aided-Design (CAD) configurations, structural finite element models, material property and stress information, structural and rigid-body dynamic model information, and linear system matrices for control law formulation among various commercial applications programs through a common database. Although general in its formulation, IMAT was developed specifically to aid in the evaluation of the structures. A description of the IMAT system and results of an application of the system are given.

Effect of freeze-dryer design on drying rate of an amorphous protein-formulation determined with a gravimetric technique.

PubMed

Gieseler, Henning; Lee, Geoffrey

2008-01-01

A freeze-drying balance was used to determine momentary drying-rate, m(t), of a sucrose/BSA formulation contained in a vial with varying shelf packing density, Ø2. A comparison between two different laboratory-scale freeze-dryers was made. The effects of Ø2 on m(t) differed between the two units, attributed to drying chamber design and its effects on heat transfer. At high Ø2 the differences are annulled because of the shielding effects of surrounding vials. Parallel effects of Ø2 were also found on product temperature, Tb, measured in the balance vial. Tb was used to calculate vial heat transfer coefficient, Kv. Kv was strongly reduced with increasing Ø2, but reached a plateau value at high Ø2.

A new hybrid transfinite element computational methodology for applicability to conduction/convection/radiation heat transfer

NASA Technical Reports Server (NTRS)

Tamma, Kumar K.; Railkar, Sudhir B.

1988-01-01

This paper describes new and recent advances in the development of a hybrid transfinite element computational methodology for applicability to conduction/convection/radiation heat transfer problems. The transfinite element methodology, while retaining the modeling versatility of contemporary finite element formulations, is based on application of transform techniques in conjunction with classical Galerkin schemes and is a hybrid approach. The purpose of this paper is to provide a viable hybrid computational methodology for applicability to general transient thermal analysis. Highlights and features of the methodology are described and developed via generalized formulations and applications to several test problems. The proposed transfinite element methodology successfully provides a viable computational approach and numerical test problems validate the proposed developments for conduction/convection/radiation thermal analysis.

Radiative interactions in laminar duct flows

NASA Technical Reports Server (NTRS)

Trivedi, P. A.; Tiwari, S. N.

1990-01-01

Analyses and numerical procedures are presented for infrared radiative energy transfer in gases when other modes of energy transfer occur simultaneously. Two types of geometries are considered, a parallel plate duct and a circular duct. Fully developed laminar incompressible flows of absorbing-emitting species in black surfaced ducts are considered under the conditions of uniform wall heat flux. The participating species considered are OH, CO, CO2, and H2O. Nongray as well as gray formulations are developed for both geometries. Appropriate limiting solutions of the governing equations are obtained and conduction-radiation interaction parameters are evaluated. Tien and Lowder's wide band model correlation was used in nongray formulation. Numerical procedures are presented to solve the integro-differential equations for both geometries. The range of physical variables considered are 300 to 2000 K for temperature, 0.1 to 100.0 atm for pressure, and 0.1 to 100 cm spacings between plates/radius of the tube. An extensive parametric study based on nongray formulation is presented. Results obtained for different flow conditions indicate that the radiative interactions can be quite significant in fully developed incompressible flows.

Robust fixed order dynamic compensation for large space structure control

NASA Technical Reports Server (NTRS)

Calise, Anthony J.; Byrns, Edward V., Jr.

1989-01-01

A simple formulation for designing fixed order dynamic compensators which are robust to both uncertainty at the plant input and structured uncertainty in the plant dynamics is presented. The emphasis is on designing low order compensators for systems of high order. The formulation is done in an output feedback setting which exploits an observer canonical form to represent the compensator dynamics. The formulation also precludes the use of direct feedback of the plant output. The main contribution lies in defining a method for penalizing the states of the plant and of the compensator, and for choosing the distribution on initial conditions so that the loop transfer matrix approximates that of a full state design. To improve robustness to parameter uncertainty, the formulation avoids the introduction of sensitivity states, which has led to complex formulations in earlier studies where only structured uncertainty has been considered.

Optimal orbit transfer suitable for large flexible structures

NASA Technical Reports Server (NTRS)

Chatterjee, Alok K.

1989-01-01

The problem of continuous low-thrust planar orbit transfer of large flexible structures is formulated as an optimal control problem with terminal state constraints. The dynamics of the spacecraft motion are treated as a point-mass central force field problem; the thrust-acceleration magnitude is treated as an additional state variable; and the rate of change of thrust-acceleration is treated as a control variable. To ensure smooth transfer, essential for flexible structures, an additional quadratic term is appended to the time cost functional. This term penalizes any abrupt change in acceleration. Numerical results are presented for the special case of a planar transfer.

Derivation and application of the reciprocity relations for radiative transfer with internal illumination

NASA Technical Reports Server (NTRS)

Cogley, A. C.

1975-01-01

A Green's function formulation is used to derive basic reciprocity relations for planar radiative transfer in a general medium with internal illumination. Reciprocity (or functional symmetry) allows an explicit and generalized development of the equivalence between source and probability functions. Assuming similar symmetry in three-dimensional space, a general relationship is derived between planar-source intensity and point-source total directional energy. These quantities are expressed in terms of standard (universal) functions associated with the planar medium, while all results are derived from the differential equation of radiative transfer.

What is the Nondominated Formulation? A Demonstration of de Novo Water Supply Portfolio Planning Under Deep Uncertainty

NASA Astrophysics Data System (ADS)

Kasprzyk, J. R.; Reed, P. M.; Characklis, G. W.; Kirsch, B. R.

2010-12-01

This paper proposes and demonstrates a new interactive framework for sensitivity-informed de Novo programming, in which a learning approach to formulating decision problems can confront the deep uncertainty within water management problems. The framework couples global sensitivity analysis using Sobol’ variance decomposition with multiobjective evolutionary algorithms (MOEAs) to generate planning alternatives and test their robustness to new modeling assumptions and scenarios. We explore these issues within the context of a risk-based water supply management problem, where a city seeks the most efficient use of a water market. The case study examines a single city’s water supply in the Lower Rio Grande Valley (LRGV) in Texas, using both a 10-year planning horizon and an extreme single-year drought scenario. The city’s water supply portfolio comprises a volume of permanent rights to reservoir inflows and use of a water market through anticipatory thresholds for acquiring transfers of water through optioning and spot leases. Diagnostic information from the Sobol’ variance decomposition is used to create a sensitivity-informed problem formulation testing different decision variable configurations, with tradeoffs for the formulation solved using a MOEA. Subsequent analysis uses the drought scenario to expose tradeoffs between long-term and short-term planning and illustrate the impact of deeply uncertain assumptions on water availability in droughts. The results demonstrate water supply portfolios’ efficiency, reliability, and utilization of transfers in the water supply market and show how to adaptively improve the value and robustness of our problem formulations by evolving our definition of optimality to discover key tradeoffs.

A proposed method for enhanced eigen-pair extraction using finite element methods: Theory and application

NASA Technical Reports Server (NTRS)

Jara-Almonte, J.; Mitchell, L. D.

1988-01-01

The paper covers two distinct parts: theory and application. The goal of this work was the reduction of model size with an increase in eigenvalue/vector accuracy. This method is ideal for the condensation of large truss- or beam-type structures. The theoretical approach involves the conversion of a continuum transfer matrix beam element into an 'Exact' dynamic stiffness element. This formulation is implemented in a finite element environment. This results in the need to solve a transcendental eigenvalue problem. Once the eigenvalue is determined the eigenvectors can be reconstructed with any desired spatial precision. No discretization limitations are imposed on the reconstruction. The results of such a combined finite element and transfer matrix formulation is a much smaller FEM eigenvalue problem. This formulation has the ability to extract higher eigenvalues as easily and as accurately as lower eigenvalues. Moreover, one can extract many more eigenvalues/vectors from the model than the number of degrees of freedom in the FEM formulation. Typically, the number of eigenvalues accurately extractable via the 'Exact' element method are at least 8 times the number of degrees of freedom. In contrast, the FEM usually extracts one accurate (within 5 percent) eigenvalue for each 3-4 degrees of freedom. The 'Exact' element results in a 20-30 improvement in the number of accurately extractable eigenvalues and eigenvectors.

Development and experimental design of a novel controlled-release matrix tablet formulation for indapamide hemihydrate.

PubMed

Antovska, Packa; Ugarkovic, Sonja; Petruševski, Gjorgji; Stefanova, Bosilka; Manchevska, Blagica; Petkovska, Rumenka; Makreski, Petre

2017-11-01

Development, experimental design and in vitro in vivo correlation (IVIVC) of controlled-release matrix formulation. Development of novel oral controlled delivery system for indapamide hemihydrate, optimization of the formulation by experimental design and evaluation regarding IVIVC on a pilot scale batch as a confirmation of a well-established formulation. In vitro dissolution profiles of controlled-release tablets of indapamide hemihydrate from four different matrices had been evaluated in comparison to the originator's product Natrilix (Servier) as a direction for further development and optimization of a hydroxyethylcellulose-based matrix controlled-release formulation. A central composite factorial design had been applied for the optimization of a chosen controlled-release tablet formulation. The controlled-release tablets with appropriate physical and technological properties had been obtained with a matrix: binder concentration variations in the range: 20-40w/w% for the matrix and 1-3w/w% for the binder. The experimental design had defined the design space for the formulation and was prerequisite for extraction of a particular formulation that would be a subject for transfer on pilot scale and IVIV correlation. The release model of the optimized formulation has shown best fit to the zero order kinetics depicted with the Hixson-Crowell erosion-dependent mechanism of release. Level A correlation was obtained.

Bus network redesign for inner southeast suburbs of Melbourne, Australia

NASA Astrophysics Data System (ADS)

Pandangwati, S. T.; Milyanab, N. A.

2017-06-01

Public transport is the most effective mode of transport in the era of climate change and oil depletion. It can address climate change issues by reducing urban greenhouse gas emission and oil consumption while at the same time improving mobility. However, many public transport networks are not effective and instead create high operating costs with low frequencies and occupancy. Melbourne is one example of a metropolitan area that faces this problem. Even though the city has well-integrated train and tram networks, Melbourne’s bus network still needs to be improved. This study used network planning approach to redesign the bus network in the City of Glen Eira, a Local Government Area (LGA) in the southeastern part of Metropolitan Melbourne. The study area is the area between Gardenvale North and Oakleigh Station, as well as between Caulfield and Patterson Stations. This area needs network improvement mainly because of the meandering bus routes that run within it. This study aims to provide recommendations for improving the performance of bus services by reducing meandering routes, improving transfer point design and implementing coordinated timetables. The recommendations were formulated based on a ‘ready-made’ concept to increase bus occupancy. This approach can be implemented in other cities with similar problems and characteristics including those in Indonesia.

Improved in vivo gene transfer into tumor tissue by stabilization of pseudodendritic oligoethylenimine-based polyplexes.

PubMed

Russ, Verena; Fröhlich, Thomas; Li, Yunqiu; Halama, Anna; Ogris, Manfred; Wagner, Ernst

2010-02-01

HD O is a low molecular weight pseudodendrimer containing oligoethylenimine and degradable hexanediol diacrylate diesters. DNA polyplexes display encouraging gene transfer efficiency in vitro and in vivo but also a limited stability under physiological conditions. This limitation must be overcome for further development into more sophisticated formulations. HD O polyplexes were laterally stabilized by crosslinking surface amines via bifunctional crosslinkers, bioreducible dithiobis(succimidyl propionate) (DSP) or the nonreducible analog disuccinimidyl suberate (DSS). Optionally, in a subsequent step, the targeting ligand transferrin (Tf) was attached to DSP-linked HD O polyplexes via Schiff base formation between HD O amino groups and Tf aldehyde groups, which were introduced into Tf by periodate oxidation of the glycosylation sites. Crosslinked DNA polyplexes showed an increased stability against exchange reaction by salt or heparin. Disulfide bond containing DSP-linked polyplexes were susceptible to reducing conditions. These polyplexes displayed the highest gene expression levels in vitro and in vivo (upon intratumoral application in mice), and these were significantly elevated and prolonged over standard or DSS-stabilized HD O formulations. DSP-stabilized HD O polyplexes with or without Tf coating were well-tolerated after intravenous application. High gene expression levels were found in tumor tissue, with negligible gene expression in any other organ. Lateral stabilization of HD O polyplexes with DSP crosslinker enhanced gene transfer efficacy and was essential for the incorporation of a ligand (Tf) into a stable particle formulation.

Evaluation of intratympanic formulations for inner ear delivery: methodology and sustained release formulation testing

PubMed Central

Liu, Hongzhuo; Feng, Liang; Tolia, Gaurav; Liddell, Mark R.; Hao, Jinsong; Li, S. Kevin

2013-01-01

A convenient and efficient in vitro diffusion cell method to evaluate formulations for inner ear delivery via the intratympanic route is currently not available. The existing in vitro diffusion cell systems commonly used to evaluate drug formulations do not resemble the physical dimensions of the middle ear and round window membrane. The objectives of this study were to examine a modified in vitro diffusion cell system of a small diffusion area for studying sustained release formulations in inner ear drug delivery and to identify a formulation for sustained drug delivery to the inner ear. Four formulations and a control were examined in this study using cidofovir as the model drug. Drug release from the formulations in the modified diffusion cell system was slower than that in the conventional diffusion cell system due to the decrease in the diffusion surface area of the modified diffusion cell system. The modified diffusion cell system was able to show different drug release behaviors among the formulations and allowed formulation evaluation better than the conventional diffusion cell system. Among the formulations investigated, poly(lactic-co-glycolic acid)–poly(ethylene glycol)–poly(lactic-co-glycolic acid) triblock copolymer systems provided the longest sustained drug delivery, probably due to their rigid gel structures and/or polymer-to-cidofovir interactions. PMID:23631539

Prediction and rational correlation of thermophoretically reduced particle mass transfer to hot surfaces across laminar or turbulent forced-convection gas boundary layers

NASA Technical Reports Server (NTRS)

Gokoglu, Suleyman A.; Rosner, Daniel E.

1986-01-01

A formulation previously developed to predict and correlate the thermophoretically-augmented submicron particle mass transfer rate to cold surfaces is found to account for the thermophoretically reduced particle mass transfer rate to overheated surfaces such that thermophoresis brings about a 10-decade reduction below the convective mass transfer rate expected by pure Brownian diffusion and convection alone. Thermophoretic blowing is shown to produce effects on particle concentration boundary-layer (BL) structure and wall mass transfer rates similar to those produced by real blowing through a porous wall. The applicability of the correlations to developing BL-situations is demonstrated by a numerical example relevant to wet-steam technology.

Commercial non-aerospace technology transfer program for the 2000s: Strategic analysis and implementation

NASA Technical Reports Server (NTRS)

Horsham, Gary A. P.

1992-01-01

This report presents a strategic analysis and implementation plan for NASA's Office of Commercial Programs (OCP), Technology Transfer Division's (TTD), Technology Transfer Program. The main objectives of this study are to: (1) characterize the NASA TTD's environment and past organizational structure; (2) clearly identify current and prospective programmatic efforts; (3) determine an evolutionary view of an organizational structure which could lead to the accomplishment of NASA's future technology transfer aims; and (4) formulate a strategy and plan to improve NASA's (and other federal agencies) ability to transfer technology to the non-aerospace sectors of the U.S. economy. The planning horizon for this study extends through the remainder of the 1990s to the year 2000.

Finite element procedures for coupled linear analysis of heat transfer, fluid and solid mechanics

NASA Technical Reports Server (NTRS)

Sutjahjo, Edhi; Chamis, Christos C.

1993-01-01

Coupled finite element formulations for fluid mechanics, heat transfer, and solid mechanics are derived from the conservation laws for energy, mass, and momentum. To model the physics of interactions among the participating disciplines, the linearized equations are coupled by combining domain and boundary coupling procedures. Iterative numerical solution strategy is presented to solve the equations, with the partitioning of temporal discretization implemented.

The Cryogenic Propellant Storage and Transfer Technology Demonstration Mission:. [Progress and Transition

NASA Technical Reports Server (NTRS)

Meyer, Michael L.; Taylor, William J.; Ginty, Carol A.; Melis, Matthew E.

2014-01-01

This presentation provides an overview of the Cryogenic Propellant Storage and Transfer (CPST) Mission from formulation through Systems Requirements Review and into preparation for Preliminary Design Review. Accomplishments of the technology maturation phase of the project are included. The presentation then summarizes the transition, due to Agency budget constraints, of CPST from a flight project into a ground project titled evolvable Cryogenics (eCryo).

JPRS Report, Science & Technology, USSR: Engineering & Equipment

DTIC Science & Technology

1988-10-05

Transfer of the results of scientific and technical or design work to the client enterprise is formulated by a bilateral acceptance-turnover report... designer , bookkeeper, account and so on). The "screen" language of documents may now emerge as this means. The concept of transfer of paper forms to...belt conveyors manufactured by enterprises of various machine building subindustries. In existing designs of pulleys with outside bearing assemblies

Transmit coil design for Wireless Power Transfer for medical implants.

PubMed

Lemdiasov, Rosti; Venkatasubramanian, Arun

2017-07-01

A new design approach for the design of transmit coils for Wireless Power Transfer (WPT) is presented. The theoretical formulation involves a figure of merit that has to be maximized to solve for the surface current. Numerical predictions and comparisons with practical measurements for the coil parameters (inductance. resistance) underscore the success of this approach in terms of achieving strong coupling with a receive coil while maintaining low resistance.

Heat transfer in damaged material

NASA Astrophysics Data System (ADS)

Kruis, J.

2013-10-01

Fully coupled thermo-mechanical analysis of civil engineering problems is studied. The mechanical analysis is based on damage mechanics which is useful for modeling of behaviour of quasi-brittle materials, especially in tension. The damage is assumed to be isotropic. The heat transfer is assumed in the form of heat conduction governed by the Fourier law and heat radiation governed by the Stefan-Boltzmann law. Fully coupled thermo-mechanical problem is formulated.

Dissipation kinetics of beta-cyfluthrin and imidacloprid in tea and their transfer from processed tea to infusion.

PubMed

Paramasivam, M; Deepa, M; Selvi, C; Chandrasekaran, S

2017-10-01

Dissipation kinetics of mixed formulation consisting beta-cyfluthrin and imidacloprid in tea crop under an open field ecosystem was investigated. The mixed formulation was applied on tea plant at recommended (27 + 63) and double the recommended (54 + 126g a.i./ha) dose and residues were determined using gas chromatography-electron capture detector and high performance liquid chromatography-photodiode array detector for beta-cyfluthrin and imidacloprid, respectively. The limit of quantification of analytical method was 0.05µg/g and the average recoveries were ranged from 88.36% to 103.49% with relative standard deviations of less than 6% at three spiked levels. The experimental results showed that in the green tea leaves imidacloprid dissipated faster than beta-cyfluthrin with the half-life ranging between 1.20-1.39 and 2.89-3.15days, respectively. The beta-cyfluthrin residues present in the processed tea not transferred into the tea infusion during the infusion process and imidacloprid transferred in the range 43.12-49.7%. On the basis of the transfer of residues from processed tea to infusion, a waiting period of 17 days for tea plucking after pesticide application at recommended dose may be suggested. Copyright © 2017 Elsevier Inc. All rights reserved.

The introduction of buprenorphine-naloxone film in opioid substitution therapy in Australia: Uptake and issues arising from changing buprenorphine formulations.

PubMed

Larance, Briony; Dietze, Paul; Ali, Robert; Lintzeris, Nicholas; White, Nancy; Jenkinson, Rebecca; Degenhardt, Louisa

2015-11-01

Buprenorphine-naloxone (BNX) film for opioid dependence treatment was introduced in Australia in 2011. A key difference in State policy approaches saw transfer from BNX tablets to BNX film mandated in South Australia (SA) with New South Wales (NSW) and Victoria (VIC) having less stringent policies. This study examined (i) how initiations and transfers were implemented, (ii) the profile and predictors of adverse effects as self-reported by BNX film clients, and (iii) dosing issues. Survey of 334 buprenorphine (BPN), BNX tablet and BNX film clients and semi-structured interviews with 39 key experts (KEs) in 2012. Comparisons are made between clients interviewed in SA versus NSW and VIC combined. Among the 180 current BNX film clients, 23% started treatment on BNX film, 18% requested a transfer to BNX film and 59% (n = 106) reported their clinic/prescriber recommended transfer to BNX film. Among clients who were offered but refused a transfer to BNX film (n = 66), the most common reason was 'I am happy with my current treatment and do not see a reason to change' (53%). Some opioid substitution therapy clients and KE viewed transfers as 'forced' (i.e. no choice of buprenorphine formulation). Multivariable regression showed residing in SA (vs. NSW/VIC) and a shorter length of current treatment episode were associated with more BNX film-attributed adverse effects but clinic/prescriber-recommended transfer was not. The introduction of BNX film in Australia varied across States. A perception of restricted choice in medication may have undermined initial acceptance in SA. © 2015 Australasian Professional Society on Alcohol and other Drugs.

Galvanostatic Intermittent Titration and Performance Based Analysis of LiNi 0.5 Co 0.2 Mn 0.3 O 2 Cathode

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

Verma, Ankit; Smith, Kandler; Santhanagopalan, Shriram

Galvanostatic intermittent titration technique (GITT) - a popular method for characterizing kinetic and transport properties of battery electrodes - is predicated on the proper evaluation of electrode active area. LiNi 0.5044Co 0.1986Mn 0.2970O 2 (NCM523) material exhibits a complex morphology in which sub-micron primary particles aggregate to form secondary particle agglomerates. Our work proposes a new active area formulation for primary/secondary particle agglomerate materials to better mimic the morphology of NCM532 electrodes. Furthermore, this formulation is then coupled with macro-homogeneous models to simulate GITT and half-cell performance of NCM523 electrodes. Subsequently, the model results are compared against the experimental resultsmore » to refine the area formulation. A single parameter, the surface roughness factor, is proposed to mimic the change in interfacial area, diffusivity and exchange current density simultaneously and detailed modeling results are presented to provide valuable insights into the efficacy of the formulation.« less

Galvanostatic Intermittent Titration and Performance Based Analysis of LiNi 0.5Co 0.2 Mn 0.3O 2Cathode

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

Verma, Ankit; Smith, Kandler; Santhanagopalan, Shriram

Galvanostatic intermittent titration technique (GITT) – a popular method for characterizing kinetic and transport properties of battery electrodes – is predicated on the proper evaluation of electrode active area. LiNi0.5044Co0.1986Mn0.2970O2 (NCM523) material exhibits a complex morphology in which sub-micron primary particles aggregate to form secondary particle agglomerates. This work proposes a new active area formulation for primary/secondary particle agglomerate materials to better mimic the morphology of NCM532 electrodes. This formulation is then coupled with macro-homogeneous models to simulate GITT and half-cell performance of NCM523 electrodes. Subsequently, the model results are compared against the experimental results to refine the area formulation.more » A single parameter, the surface roughness factor, is proposed to mimic the change in interfacial area, diffusivity and exchange current density simultaneously and detailed modeling results are presented to provide valuable insights into the efficacy of the formulation.« less

Galvanostatic Intermittent Titration and Performance Based Analysis of LiNi 0.5 Co 0.2 Mn 0.3 O 2 Cathode

DOE PAGES

Verma, Ankit; Smith, Kandler; Santhanagopalan, Shriram; ...

2017-11-03

Galvanostatic intermittent titration technique (GITT) - a popular method for characterizing kinetic and transport properties of battery electrodes - is predicated on the proper evaluation of electrode active area. LiNi 0.5044Co 0.1986Mn 0.2970O 2 (NCM523) material exhibits a complex morphology in which sub-micron primary particles aggregate to form secondary particle agglomerates. Our work proposes a new active area formulation for primary/secondary particle agglomerate materials to better mimic the morphology of NCM532 electrodes. Furthermore, this formulation is then coupled with macro-homogeneous models to simulate GITT and half-cell performance of NCM523 electrodes. Subsequently, the model results are compared against the experimental resultsmore » to refine the area formulation. A single parameter, the surface roughness factor, is proposed to mimic the change in interfacial area, diffusivity and exchange current density simultaneously and detailed modeling results are presented to provide valuable insights into the efficacy of the formulation.« less

Next generation macrocyclic and acyclic cationic lipids for gene transfer: Synthesis and in vitro evaluation.

PubMed

Jubeli, Emile; Maginty, Amanda B; Abdul Khalique, Nada; Raju, Liji; Abdulhai, Mohamad; Nicholson, David G; Larsen, Helge; Pungente, Michael D; Goldring, William P D

2015-10-01

Previously we reported the synthesis and in vitro evaluation of four novel, short-chain cationic lipid gene delivery vectors, characterized by acyclic or macrocyclic hydrophobic regions composed of, or derived from, two 7-carbon chains. Herein we describe a revised synthesis of an expanded library of related cationic lipids to include extended chain analogues, their formulation with plasmid DNA (pDNA) and in vitro delivery into Chinese hamster ovarian (CHO-K1) cells. The formulations were evaluated against each other based on structural differences in the hydrophobic domain and headgroup. Structurally the library is divided into four sets based on lipids derived from two 7- or two 11-carbon hydrophobic chains, C7 and C11 respectively, which possess either a dimethylamine or a trimethylamine derived headgroup. Each set includes four cationic lipids based on an acyclic or macrocyclic, saturated or unsaturated hydrophobic domain. All lipids were co-formulated with the commercial cationic lipid 1,2-dimyristoyl-sn-glycero-3-ethylphosphocholine (EPC) in a 1:1 molar ratio, along with one of two distinct neutral co-lipids, cholesterol or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) in an overall cationic-to-neutral lipid molar ratio of 3:2. Binding of lipid formulations with DNA, and packing morphology associated with the individual lipid-DNA complexes were characterized by gel electrophoresis and small angle X-ray diffraction (SAXD), respectively. As a general trend, lipoplex formulations based on mismatched binary cationic lipids, composed of a shorter C7 lipid and the longer lipid EPC (C14), were generally associated with higher transfection efficiency and lower cytotoxicity than their more closely matched C11/EPC binary lipid formulation counterparts. Furthermore, the cyclic lipids gave transfection levels as high as or greater than their acyclic counterparts, and formulations with cholesterol exhibited higher transfection and lower cytotoxicity than those formulated with DOPE. A number of the lipid formulations with cholesterol as co-lipid performed as well as, or better than Lipofectamine 2000™ and EPC, the two positive controls employed in these studies. These results suggest that our novel cyclic and acyclic cationic lipid vectors are effective nonviral gene transfer agents that warrant further investigation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Readily prepared biodegradable nanoparticles to formulate poorly water soluble drugs improving their pharmacological properties: The example of trabectedin.

PubMed

Capasso Palmiero, Umberto; Morosi, Lavinia; Bello, Ezia; Ponzo, Marianna; Frapolli, Roberta; Matteo, Cristina; Ferrari, Mariella; Zucchetti, Massimo; Minoli, Lucia; De Maglie, Marcella; Romanelli, Pierpaolo; Morbidelli, Massimo; D'Incalci, Maurizio; Moscatelli, Davide

2018-04-28

The improvement of the pharmacological profile of lipophilic drug formulations is one of the main successes achieved using nanoparticles (NPs) in medicine. However, the complex synthesis procedure and numerous post-processing steps hamper the cost-effective use of these formulations. In this work, an approach which requires only a syringe to produce self-assembling biodegradable and biocompatible poly(caprolactone)-based NPs is developed. The effective synthesis of monodisperse NPs has been made possible by the optimization of the block-copolymer synthesized via a combination of ring opening polymerization and reversible addition-fragmentation chain transfer polymerization. These NPs can be used to formulate lipophilic drugs that are barely soluble in water, such as trabectedin, a potent anticancer therapeutic. Its biodistribution and antitumor activity have been compared with the commercially available formulation Yondelis®. The results indicate that this trabectedin NP formulation performs with the same antitumor activity as Yondelis®, but does not have the drawback of severe local vascular toxicity in the injection site. Copyright © 2018 Elsevier B.V. All rights reserved.

Towards ambient temperature-stable vaccines: the identification of thermally stabilizing liquid formulations for measles virus using an innovative high-throughput infectivity assay.

PubMed

Schlehuber, Lisa D; McFadyen, Iain J; Shu, Yu; Carignan, James; Duprex, W Paul; Forsyth, William R; Ho, Jason H; Kitsos, Christine M; Lee, George Y; Levinson, Douglas A; Lucier, Sarah C; Moore, Christopher B; Nguyen, Niem T; Ramos, Josephine; Weinstock, B André; Zhang, Junhong; Monagle, Julie A; Gardner, Colin R; Alvarez, Juan C

2011-07-12

As a result of thermal instability, some live attenuated viral (LAV) vaccines lose substantial potency from the time of manufacture to the point of administration. Developing regions lacking extensive, reliable refrigeration ("cold-chain") infrastructure are particularly vulnerable to vaccine failure, which in turn increases the burden of disease. Development of a robust, infectivity-based high throughput screening process for identifying thermostable vaccine formulations offers significant promise for vaccine development across a wide variety of LAV products. Here we describe a system that incorporates thermal stability screening into formulation design using heat labile measles virus as a prototype. The screening of >11,000 unique formulations resulted in the identification of liquid formulations with marked improvement over those used in commercial monovalent measles vaccines, with <1.0 log loss of activity after incubation for 8h at 40°C. The approach was shown to be transferable to a second unrelated virus, and therefore offers significant promise towards the optimization of formulation for LAV vaccine products. Copyright © 2011 Elsevier Ltd. All rights reserved.

A constrained multinomial Probit route choice model in the metro network: Formulation, estimation and application

PubMed Central

Zhang, Yongsheng; Wei, Heng; Zheng, Kangning

2017-01-01

Considering that metro network expansion brings us with more alternative routes, it is attractive to integrate the impacts of routes set and the interdependency among alternative routes on route choice probability into route choice modeling. Therefore, the formulation, estimation and application of a constrained multinomial probit (CMNP) route choice model in the metro network are carried out in this paper. The utility function is formulated as three components: the compensatory component is a function of influencing factors; the non-compensatory component measures the impacts of routes set on utility; following a multivariate normal distribution, the covariance of error component is structured into three parts, representing the correlation among routes, the transfer variance of route, and the unobserved variance respectively. Considering multidimensional integrals of the multivariate normal probability density function, the CMNP model is rewritten as Hierarchical Bayes formula and M-H sampling algorithm based Monte Carlo Markov Chain approach is constructed to estimate all parameters. Based on Guangzhou Metro data, reliable estimation results are gained. Furthermore, the proposed CMNP model also shows a good forecasting performance for the route choice probabilities calculation and a good application performance for transfer flow volume prediction. PMID:28591188

Theory and computation of optimal low- and medium-thrust transfers

NASA Technical Reports Server (NTRS)

Chuang, C.-H.

1993-01-01

This report presents the formulation of the optimal low- and medium-thrust orbit transfer control problem and methods for numerical solution of the problem. The problem formulation is for final mass maximization and allows for second-harmonic oblateness, atmospheric drag, and three-dimensional, non-coplanar, non-aligned elliptic terminal orbits. We setup some examples to demonstrate the ability of two indirect methods to solve the resulting TPBVP's. The methods demonstrated are the multiple-point shooting method as formulated in H. J. Oberle's subroutine BOUNDSCO, and the minimizing boundary-condition method (MBCM). We find that although both methods can converge solutions, there are trade-offs to using either method. BOUNDSCO has very poor convergence for guesses that do not exhibit the correct switching structure. MBCM, however, converges for a wider range of guesses. However, BOUNDSCO's multi-point structure allows more freedom in quesses by increasing the node points as opposed to only quessing the initial state in MBCM. Finally, we note an additional drawback for BOUNDSCO: the routine does not supply information to the users routines for switching function polarity but only the location of a preset number of switching points.

Effects of acuity-adaptable rooms on flow of patients and delivery of care.

PubMed

Hendrich, Ann L; Fay, Joy; Sorrells, Amy K

2004-01-01

Delayed transfers of patients between nursing units and lack of available beds are significant problems that increase costs and decrease quality of care and satisfaction among patients and staff. To test whether use of acuity-adaptable rooms helps solve problems with transfers of patients, satisfaction levels, and medical errors. A pre-post method was used to compare the effects of environmental design on various clinical and financial measures. Twelve outcome-based questions were formulated as the basis for inquiry. Two years of baseline data were collected before the unit moved and were compared with 3 years of data collected after the move. Significant improvements in quality and operational cost occurred after the move, including a large reduction in clinician handoffs and transfers; reductions in medication error and patient fall indexes; improvements in predictive indicators of patients' satisfaction; decrease in budgeted nursing hours per patient day and increased available nursing time for direct care without added cost; increase in patient days per bed, with a smaller bed base (number of beds per patient days). Some staff turnover occurred during the first year; turnover stabilized thereafter. Data in 5 key areas (flow of patients and hospital capacity, patients' dissatisfaction, sentinel events, mean length of stay, and allocation of nursing productivity) appear to be sufficient to test the business case for future investment in partial or complete replication of this model with appropriate populations of patients.

Air-cooling characteristics of simulated grape packages

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

Frederick, R.L.; Comunian, F.

Experimental simulation of the external forced convection on the outside of grape packages was performed. Average heat transfer coefficients for air flow around such containers were found to range from 8 to 13.4 W/(m[sup 2]K). A physical description of the convective process was formulated on the basis of data obtained in three types of experiment. Expressions for the average heat transfer coefficient from single packages in air flow were proposed.

Substrate mass transfer: analytical approach for immobilized enzyme reactions

NASA Astrophysics Data System (ADS)

Senthamarai, R.; Saibavani, T. N.

2018-04-01

In this paper, the boundary value problem in immobilized enzyme reactions is formulated and approximate expression for substrate concentration without external mass transfer resistance is presented. He’s variational iteration method is used to give approximate and analytical solutions of non-linear differential equation containing a non linear term related to enzymatic reaction. The relevant analytical solution for the dimensionless substrate concentration profile is discussed in terms of dimensionless reaction parameters α and β.

Fluctuation theorem for entropy production during effusion of an ideal gas with momentum transfer.

PubMed

Wood, Kevin; Van den Broeck, C; Kawai, R; Lindenberg, Katja

2007-06-01

We derive an exact expression for entropy production during effusion of an ideal gas driven by momentum transfer in addition to energy and particle flux. Following the treatment in Cleuren [Phys. Rev. E 74, 021117 (2006)], we construct a master equation formulation of the process and explicitly verify the thermodynamic fluctuation theorem, thereby directly exhibiting its extended applicability to particle flows and hence to hydrodynamic systems.

Direct numerical simulations of fluid flow, heat transfer and phase changes

NASA Technical Reports Server (NTRS)

Juric, D.; Tryggvason, G.; Han, J.

1997-01-01

Direct numerical simulations of fluid flow, heat transfer, and phase changes are presented. The simulations are made possible by a recently developed finite difference/front tracking method based on the one-field formulation of the governing equations where a single set of conservation equations is written for all the phases involved. The conservation equations are solved on a fixed rectangular grid, but the phase boundaries are kept sharp by tracking them explicitly by a moving grid of lower dimension. The method is discussed and applications to boiling heat transfer and the solidification of drops colliding with a wall are shown.

Matrix Transfer Function Design for Flexible Structures: An Application

NASA Technical Reports Server (NTRS)

Brennan, T. J.; Compito, A. V.; Doran, A. L.; Gustafson, C. L.; Wong, C. L.

1985-01-01

The application of matrix transfer function design techniques to the problem of disturbance rejection on a flexible space structure is demonstrated. The design approach is based on parameterizing a class of stabilizing compensators for the plant and formulating the design specifications as a constrained minimization problem in terms of these parameters. The solution yields a matrix transfer function representation of the compensator. A state space realization of the compensator is constructed to investigate performance and stability on the nominal and perturbed models. The application is made to the ACOSSA (Active Control of Space Structures) optical structure.

Technology transfer in the NASA Ames Advanced Life Support Division

NASA Technical Reports Server (NTRS)

Connell, Kathleen; Schlater, Nelson; Bilardo, Vincent; Masson, Paul

1992-01-01

This paper summarizes a representative set of technology transfer activities which are currently underway in the Advanced Life Support Division of the Ames Research Center. Five specific NASA-funded research or technology development projects are synopsized that are resulting in transfer of technology in one or more of four main 'arenas:' (1) intra-NASA, (2) intra-Federal, (3) NASA - aerospace industry, and (4) aerospace industry - broader economy. Each project is summarized as a case history, specific issues are identified, and recommendations are formulated based on the lessons learned as a result of each project.

Antioxidant-based topical formulations influence on the inflammatory response of Japanese skin: A clinical study using non-invasive techniques.

PubMed

Wagemaker, Tais A L; Maia Campos, Patrícia M B G; Shimizu, Kenji; Kyotani, Daiki; Yoshida, Daisuke

2017-08-01

Cutaneous irritants exposure induces an excess of ROS in the skin and can ensue an inflammatory response. Topical antioxidant-based formulations can help to counteract ROS generation. This study evaluated the influence of antioxidant-based topical formulations on the inflammatory response of skin, using a combination of in vivo real-time non-invasive techniques. Nine test areas were defined on each volar forearm of the 25 Japanese volunteers. Measurements were performed before and after treatment with 15μL of a 5% sodium dodecyl sulfate solution and 15μL of the same based formulation or the vehicle with 1% of the antioxidants. Volunteers without antioxidant treatment showed more pronounced erythematous areas. Transepidermal water loss of areas treated with green tea polyphenol (GTP)-based formulation showed fully recovered skin. Skin barrier damage caused by repeated applications of SDS showed characteristic alterations, detectable by in vivo confocal microscopy such as desquamation, spongiosis and inflammatory infiltrates. The majority of confocal microscopy inflammation signs were found in skin without treatment followed by the vehicle. Ascorbyl tetraisopalmitate, Coenzyme Q 10 , GTP- and Resveratrol-based formulations reduced the anti-inflammatory cytokines release and attenuated inflammatory signs. The combination of techniques provides results that highlight the importance of antioxidant-based formulations for rapid skin recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

Computer-Based Training: Will it Replace You?

ERIC Educational Resources Information Center

Hudson, William J.

1982-01-01

Examines myths and fears about computer-based training (displaces trainers, dehumanizes learners), lists what computers cannot do (analyze needs, formulate objectives, act as subject experts), and what they can do effectively (handle knowledge transfer, provide simulation). (SK)

A piezoelectric transformer

NASA Technical Reports Server (NTRS)

Won, C. C.

1993-01-01

This work describes a modeling and design method whereby a piezoelectric system is formulated by two sets of second-order equations, one for the mechanical system, and the other for the electrical system, coupled through the piezoelectric effect. The solution to this electromechanical coupled system gives a physical interpretation of the piezoelectric effect as a piezoelectric transformer that is a part of the piezoelectric system, which transfers the applied mechanical force into a force-controlled current source, and short circuit mechanical compliance into capacitance. It also transfers the voltage source into a voltage-controlled relative velocity input, and free motional capacitance into mechanical compliance. The formulation and interpretation simplify the modeling of smart structures and lead to physical insight that aids the designer. Due to its physical realization, the smart structural system can be unconditional stable and effectively control responses. This new concept has been demonstrated in three numerical examples for a simple piezoelectric system.

Research on output feedback control

NASA Technical Reports Server (NTRS)

Calise, A. J.; Kramer, F. S.

1985-01-01

In designing fixed order compensators, an output feedback formulation has been adopted by suitably augmenting the system description to include the compensator states. However, the minimization of the performance index over the range of possible compensator descriptions was impeded due to the nonuniqueness of the compensator transfer function. A controller canonical form of the compensator was chosen to reduce the number of free parameters to its minimal number in the optimization. In the MIMO case, the controller form requires a prespecified set of ascending controllability indices. This constraint on the compensator structure is rather innocuous in relation to the increase in convergence rate of the optimization. Moreover, the controller form is easily relatable to a unique controller transfer function description. This structure of the compensator does not require penalizing the compensator states for a nonzero or coupled solution, a problem that occurs when following a standard output feedback synthesis formulation.

Study on forced convective heat transfer of non-newtonian nanofluids

NASA Astrophysics Data System (ADS)

He, Yurong; Men, Yubin; Liu, Xing; Lu, Huilin; Chen, Haisheng; Ding, Yulong

2009-03-01

This paper is concerned with the forced convective heat transfer of dilute liquid suspensions of nanoparticles (nanofluids) flowing through a straight pipe under laminar conditions. Stable nanofluids are formulated by using the high shear mixing and ultrasonication methods. They are then characterised for their size, surface charge, thermal and rheological properties and tested for their convective heat transfer behaviour. Mathematical modelling is performed to simulate the convective heat transfer of nanofluids using a single phase flow model and considering nanofluids as both Newtonian and non-Newtonian fluid. Both experiments and mathematical modelling show that nanofluids can substantially enhance the convective heat transfer. Analyses of the results suggest that the non-Newtonian character of nanofluids influences the overall enhancement, especially for nanofluids with an obvious non-Newtonian character.

Urban Principle of Water Sensitive Design in Kampung Kamboja at Pontianak City

NASA Astrophysics Data System (ADS)

Hasriyanti, N.; Ryanti, E.

2017-07-01

This study will define the design principles of settlement area banks of the Kapuas Pontianak to approach the concept of water sensitive urban design (WSUD) in densely populated residential areas. Using a case study of a region densely located on the banks of the river with engineering literature to formulate the aspects taken into consideration and the components are arranged in the design, analysis descriptive paradigm rationalistic to identify the characteristics of residential areas riverbank with consideration of elements WSUD and formulate design principles residential area that is sensitive to water. This research is important to do because of problems related to the water management system in the settlement bank of the river in the city of Pontianak do not maximize. So that the primacy of this study contains several objectives to be achieved is to identify the characteristics of the settlement area riverbanks under consideration aspects areas design that is sensitive to water and principle areas design that will formulate the structure of the existing problems related to the needs of the community infrastructure facilities infrastructure neighborhoods and formulate and create guidelines for appropriate technology for integrated water management systems in the residential area of the riverbank and engineering design for the settlements are sensitive to water (WSUD). The final aim of the study is expected to achieve water management systems in residential areas by utilizing the abundant rainwater availability by using LID (Low Impact Development) through the concept of urban design that sensitive water

A novel, volumizing cosmetic formulation significantly improves the appearance of target Glabellar lines, nasolabial folds, and crow's feet in a double-blind, vehicle-controlled clinical trial.

PubMed

Farris, Patricia K; Edison, Brenda L; Weinkauf, Ronni L; Green, Barbara A

2014-01-01

Facial lines and wrinkles are caused by many factors including constant exposure to external elements, such as UV rays, as well as the dynamic nature of facial expression. Many cosmetic products and procedures provide global improvement to aging skin, whereas injectable therapies are frequently utilized to diminish specific, target wrinkles. Despite their broad availability, some patients are unwilling to undergo injectables and would benefit from an effective topical option. A noninvasive option to volumize target wrinkle areas could also extend benefits of commonly used cosmetic anti-aging products. To this end, a two-step formulation containing the novel, cosmetic anti-aging ingredient, N-acetyl tyrosinamide, was developed for use on targeted wrinkle areas. The tolerability and efficacy of the serum plus cream were tested for 16 weeks in women with moderate facial photodamage on predetermined wrinkle areas (glabellar lines, nasolabial folds, under eye lines, and lateral canthal (crow's feet) wrinkles) in a single-center, randomized, double-blind, vehicle-controlled, clinical trial. Seventy women (47 Active group, 23 Vehicle group) completed the study. Digital photography, clinical grading, ultrasound and self-assessment scores confirmed improvement to wrinkle areas. The topical cosmetic formulation was statistically superior (P<0.05) to its vehicle in visually improving nasolabial folds, glabellar lines, crow's feet, and under eye wrinkles and in reducing pinch recoil time. Both the test formulation and its vehicle were tolerated well. The novel, two-step cosmetic formulation reduced the appearance of wrinkles and increased skin elasticity thus providing an effective anti-aging option for target wrinkle areas. This study suggests that in addition to its use as monotherapy for reducing targeted lines and wrinkles this cosmetic formulation may be also serve as an adjuvant to injectable therapies.

33 CFR 127.1325 - Access to marine transfer area for LHG.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Access to marine transfer area... to marine transfer area for LHG. Each operator of a waterfront facility handling LHG shall ensure that— (a) Access to the marine transfer area for LHG from shoreside and waterside is limited to— (1...

33 CFR 127.1325 - Access to marine transfer area for LHG.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Access to marine transfer area... to marine transfer area for LHG. Each operator of a waterfront facility handling LHG shall ensure that— (a) Access to the marine transfer area for LHG from shoreside and waterside is limited to— (1...

33 CFR 127.1325 - Access to marine transfer area for LHG.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Access to marine transfer area... to marine transfer area for LHG. Each operator of a waterfront facility handling LHG shall ensure that— (a) Access to the marine transfer area for LHG from shoreside and waterside is limited to— (1...

Cross mode modulation in multimode fibers.

PubMed

Kroushkov, Dimitar I; Rademacher, Georg; Petermann, Klaus

2013-05-15

We show that Kerr nonlinearity induced intermodal power transfer in a particular mode group of a multimode fiber can be formulated by the same type of equation used to describe the effect of cross polarization modulation in single-mode fibers.

Rapid and high throughput fabrication of high temperature stable structures through PDMS transfer printing

NASA Astrophysics Data System (ADS)

Hohenberger, Erik; Freitag, Nathan; Korampally, Venumadhav

2017-07-01

We report on a facile and low cost fabrication approach for structures—gratings and enclosed nanochannels, through simple solution processed chemistries in conjunction with nanotransfer printing techniques. The ink formulation primarily consisting of an organosilicate polymeric network with a small percentage of added 3-aminopropyl triethoxysilane crosslinker allows one to obtain robust structures that are not only stable towards high temperature processing steps as high as 550 °C but also exhibit exceptional stability against a host of organic solvent washes. No discernable structure distortion was observed compared to the as-printed structures (room temperature processed) when printed structures were subjected to temperatures as high as 550 °C. We further demonstrate the applicability of this technique towards the fabrication of more complex nanostructures such as enclosed channels through a double transfer method, leveraging the exceptional room temperature cross-linking ability of the printed structures and their subsequent resistance to dissolution in organic solvent washes. The exceptional temperature and physico-chemical stability of the nanotransfer printed structures makes this a useful fabrication tool that may be applied as is, or integrated with conventional lithographic techniques for the large area fabrication of functional nanostructures and devices.

An indirect latent informational conformity social influence choice model: Formulation and case study

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

Maness, Michael; Cirillo, Cinzia

The current state-of-the-art in social influence models of travel behavior is conformity models with direct benefit social influence effects. Indirect effects have seen limited development, but this paper presents a latent class discrete choice model of an indirect informational conformity hypothesis. Moreover, class membership depends on the proportion of group members who adopt a behavior. Membership into the more informed class causes changes in the preferences of those individuals thus making adoption more attractive. Equilibrium properties are derived for this model showing the possibility of multiple equilibria but under different conditions than the direct-benefit formulations. Social influence elasticity is derivedmore » for both models types. The informational conformity model can represent non-linear elasticity behavior unlike the direct-benefit formulation. Additionally, a two-stage control function is developed to obtain consistent parameter estimates in the presence of an endogenous class membership model covariate that is correlated with choice model unobservables. A case study to study social influence in bicycle ownership in the United States is presented. Our results showed that more informed households had a greater chance of owning a bike due to preference changes with less sensitivity to smaller home footprints and limited incomes. The behavioral hypothesis of positive preference change due to information transfer was confirmed. Observed ownership share closely matched predicted local-level equilibrium in some metropolitan areas but was unable to achieve expected prediction rate within confidence intervals. Finally, the elasticity of social influence was found to range locally from about 0.5% to 1.0%.« less

An indirect latent informational conformity social influence choice model: Formulation and case study

DOE PAGES

Maness, Michael; Cirillo, Cinzia

2016-11-01

The current state-of-the-art in social influence models of travel behavior is conformity models with direct benefit social influence effects. Indirect effects have seen limited development, but this paper presents a latent class discrete choice model of an indirect informational conformity hypothesis. Moreover, class membership depends on the proportion of group members who adopt a behavior. Membership into the more informed class causes changes in the preferences of those individuals thus making adoption more attractive. Equilibrium properties are derived for this model showing the possibility of multiple equilibria but under different conditions than the direct-benefit formulations. Social influence elasticity is derivedmore » for both models types. The informational conformity model can represent non-linear elasticity behavior unlike the direct-benefit formulation. Additionally, a two-stage control function is developed to obtain consistent parameter estimates in the presence of an endogenous class membership model covariate that is correlated with choice model unobservables. A case study to study social influence in bicycle ownership in the United States is presented. Our results showed that more informed households had a greater chance of owning a bike due to preference changes with less sensitivity to smaller home footprints and limited incomes. The behavioral hypothesis of positive preference change due to information transfer was confirmed. Observed ownership share closely matched predicted local-level equilibrium in some metropolitan areas but was unable to achieve expected prediction rate within confidence intervals. Finally, the elasticity of social influence was found to range locally from about 0.5% to 1.0%.« less

A vertically integrated snow/ice model over land/sea for climate models. I - Development. II - Impact on orbital change experiments

NASA Technical Reports Server (NTRS)

Neeman, Binyamin U.; Ohring, George; Joseph, Joachim H.

1988-01-01

A vertically integrated formulation (VIF) model for sea ice/snow and land snow is discussed which can simulate the nonlinear effects of heat storage and transfer through the layers of snow and ice. The VIF demonstates the accuracy of the multilayer formulation, while benefitting from the computational flexibility of linear formulations. In the second part, the model is implemented in a seasonal dynamic zonally averaged climate model. It is found that, in response to a change between extreme high and low summer insolation orbits, the winter orbital change dominates over the opposite summer change for sea ice. For snow over land the shorter but more pronounced summer orbital change is shown to dominate.

Multiconfigurational and DFT analyses of the electromeric formulation and UV-vis absorption spectra of the superoxide adduct of ferrous superoxide reductase.

PubMed

Attia, Amr A A; Cioloboc, Daniela; Lupan, Alexandru; Silaghi-Dumitrescu, Radu

2016-12-01

The putative initial adduct of ferrous superoxide reductase (SOR) with superoxide has been alternatively formulated as ferric-peroxo or ferrous-superoxo. The ~600-nm UV-vis absorption band proposed to be assigned to this adduct (either as sole intermediate in the SOR catalytic cycle, or as one of the two intermediates) has recently been interpreted as due to a ligand-to-metal charge transfer, involving thiolate and superoxide in a ferrous complex, contrary to an alternative assignment as a predominantly cysteine thiolate-to-ferric charge transfer in a ferric-peroxo electromer. In an attempt to clarify the electromeric formulation of this adduct, we report a computational study using a multiconfigurational complete active space self-consistent field (MC-CASSCF) wave function approach as well as modelling the UV-vis absorption spectra with time-dependent density functional theory (TD-DFT). The MC-CASSCF calculations disclose a weak interaction between iron and the dioxygenic ligand and a dominant configuration with an essentially ferrous-superoxo character. The computed UV-vis absorption spectra reveal a marked dependence on the choice of density functional - both in terms of location of bands and in terms of orbital contributors. For the main band in the visible region, besides the recently reported thiolate-to-superoxide charge transfer, a more salient, and less functional-dependent, feature is a thiolate-to-ferric iron charge transfer, consistent with a ferric-peroxo electromer. By contrast, the computed UV-vis spectra of a ferric-hydroperoxo SOR model match distinctly better (and with no qualitative dependence on the DFT methodology) the 600-nm band as due to a mainly thiolate-to-ferric character - supporting the assignment of the SOR "600-nm intermediate" as a S=5/2 ferric-hydroperoxo species. Copyright © 2016 Elsevier Inc. All rights reserved.

Lattice Boltzmann formulation for conjugate heat transfer in heterogeneous media.

PubMed

Karani, Hamid; Huber, Christian

2015-02-01

In this paper, we propose an approach for studying conjugate heat transfer using the lattice Boltzmann method (LBM). The approach is based on reformulating the lattice Boltzmann equation for solving the conservative form of the energy equation. This leads to the appearance of a source term, which introduces the jump conditions at the interface between two phases or components with different thermal properties. The proposed source term formulation conserves conductive and advective heat flux simultaneously, which makes it suitable for modeling conjugate heat transfer in general multiphase or multicomponent systems. The simple implementation of the source term approach avoids any correction of distribution functions neighboring the interface and provides an algorithm that is independent from the topology of the interface. Moreover, our approach is independent of the choice of lattice discretization and can be easily applied to different advection-diffusion LBM solvers. The model is tested against several benchmark problems including steady-state convection-diffusion within two fluid layers with parallel and normal interfaces with respect to the flow direction, unsteady conduction in a three-layer stratified domain, and steady conduction in a two-layer annulus. The LBM results are in excellent agreement with analytical solution. Error analysis shows that our model is first-order accurate in space, but an extension to a second-order scheme is straightforward. We apply our LBM model to heat transfer in a two-component heterogeneous medium with a random microstructure. This example highlights that the method we propose is independent of the topology of interfaces between the different phases and, as such, is ideally suited for complex natural heterogeneous media. We further validate the present LBM formulation with a study of natural convection in a porous enclosure. The results confirm the reliability of the model in simulating complex coupled fluid and thermal dynamics in complex geometries.

Geochemical mole-balance modeling with uncertain data

USGS Publications Warehouse

Parkhurst, David L.

1997-01-01

Geochemical mole-balance models are sets of chemical reactions that quantitatively account for changes in the chemical and isotopic composition of water along a flow path. A revised mole-balance formulation that includes an uncertainty term for each chemical and isotopic datum is derived. The revised formulation is comprised of mole-balance equations for each element or element redox state, alkalinity, electrons, solvent water, and each isotope; a charge-balance equation and an equation that relates the uncertainty terms for pH, alkalinity, and total dissolved inorganic carbon for each aqueous solution; inequality constraints on the size of the uncertainty terms; and inequality constraints on the sign of the mole transfer of reactants. The equations and inequality constraints are solved by a modification of the simplex algorithm combined with an exhaustive search for unique combinations of aqueous solutions and reactants for which the equations and inequality constraints can be solved and the uncertainty terms minimized. Additional algorithms find only the simplest mole-balance models and determine the ranges of mixing fractions for each solution and mole transfers for each reactant that are consistent with specified limits on the uncertainty terms. The revised formulation produces simpler and more robust mole-balance models and allows the significance of mixing fractions and mole transfers to be evaluated. In an example from the central Oklahoma aquifer, inclusion of up to 5% uncertainty in the chemical data can reduce the number of reactants in mole-balance models from seven or more to as few as three, these being cation exchange, dolomite dissolution, and silica precipitation. In another example from the Madison aquifer, inclusion of the charge-balance constraint requires significant increases in the mole transfers of calcite, dolomite, and organic matter, which reduce the estimated maximum carbon 14 age of the sample by about 10,000 years, from 22,700 years to 12,600 years.

High drug loading self-microemulsifying/micelle formulation: design by high-throughput formulation screening system and in vivo evaluation.

PubMed

Sakai, Kenichi; Obata, Kouki; Yoshikawa, Mayumi; Takano, Ryusuke; Shibata, Masaki; Maeda, Hiroyuki; Mizutani, Akihiko; Terada, Katsuhide

2012-10-01

To design a high drug loading formulation of self-microemulsifying/micelle system. A poorly-soluble model drug (CH5137291), 8 hydrophilic surfactants (HS), 10 lipophilic surfactants (LS), 5 oils, and PEG400 were used. A high loading formulation was designed by a following stepwise approach using a high-throughput formulation screening (HTFS) system: (1) an oil/solvent was selected by solubility of the drug; (2) a suitable HS for highly loading was selected by the screenings of emulsion/micelle size and phase stability in binary systems (HS, oil/solvent) with increasing loading levels; (3) a LS that formed a broad SMEDDS/micelle area on a phase diagram containing the HS and oil/solvent was selected by the same screenings; (4) an optimized formulation was selected by evaluating the loading capacity of the crystalline drug. Aqueous solubility behavior and oral absorption (Beagle dog) of the optimized formulation were compared with conventional formulations (jet-milled, PEG400). As an optimized formulation, d-α-tocopheryl polyoxyethylene 1000 succinic ester: PEG400 = 8:2 was selected, and achieved the target loading level (200 mg/mL). The formulation formed fine emulsion/micelle (49.1 nm), and generated and maintained a supersaturated state at a higher level compared with the conventional formulations. In the oral absorption test, the area under the plasma concentration-time curve of the optimized formulation was 16.5-fold higher than that of the jet-milled formulation. The high loading formulation designed by the stepwise approach using the HTFS system improved the oral absorption of the poorly-soluble model drug.

[Investigation on schistosomiasis cognitive levels of people from Chaohu area].

PubMed

Liu, Huan; Sha, Jian-jun; Huang, Hao; Cao, Zhi-guo; Zhao, Jin-hong; Li, Chao-pin

2015-12-01

To investigate the cognitive levels of people from Chaohu area, Anhui Province about the prevention and control knowledge of schistosomiasis before the water transfer project operation, so as to provide the reference for formulating the health education intervention. A schistosomiasis questionnaire survey was conducted among the students, fishermen, boat people and villagers from Chaohu selected by the random cluster sampling from May to October, 2014. A total of 1 140 questionnaires were issued with the actual recovery of 1 096 copies and 1 032 valid questionnaires. The awareness rate of prevention and control knowledge of schistosomiasis was from 11.72% to 71.71%. The highest awareness rate was in the "know schistosomiasis", however the lowest awareness rate was in the "know the intermediate host of schistosomiasis". Catching fish or shrimp in river or lake was the main way of contacting water in production activities (39.05%), and swimming or playing in river or lake was the main way of contacting water in life activities (63.18%). The prevention and control knowledge of schistosomiasis by teaching was at a rate of 41.47% on average, and the main way was anti-schistosomiasis professionals going to countryside to do health education (49.53%). That the feces directly discharged into water accounted for 91.14% in fishman and boatman. It is necessary for people from Chaohu to carry out various forms of health education of schistosomiasis prevention and control before the water transfer project operation.

Product mass transfer resistance directly determined during freeze-drying cycle runs using tunable diode laser absorption spectroscopy (TDLAS) and pore diffusion model.

PubMed

Kuu, Wei Y; O'Bryan, Kevin R; Hardwick, Lisa M; Paul, Timothy W

2011-08-01

The pore diffusion model is used to express the dry layer mass transfer resistance, [Formula: see text], as a function of the ratio r(e)/?, where r(e) is the effective pore radius and ? is the tortuosity factor of the dry layer. Using this model, the effective pore radius of the dry layer can be estimated from the sublimation rate and product temperature profiles measured during primary drying. Freeze-drying cycle runs were performed using the LyoStar II dryer (FTS Systems), with real-time sublimation rate profiles during freeze drying continuously measured by tunable diode laser absorption spectroscopy (TDLAS). The formulations chosen for demonstration of the proposed approach include 5% mannitol, 5% sucrose, 5% lactose, 3% mannitol plus 2% sucrose, and a parenteral nutrition formulation denoted VitaM12. The three different methods used for determination of the product resistance are: (1) Using both the sublimation rate and product temperature profiles, (2) using the sublimation rate profile alone, and (3) using the product temperate profile alone. Unlike the second and third methods, the computation procedure of first method does not need solution of the complex heat and mass transfer equations.

Material Properties Governing Co-Current Flame Spread: The Effect of Air Entrainment

NASA Technical Reports Server (NTRS)

Coutin, Mickael; Rangwala, Ali S.; Torero, Jose L.; Buckley, Steven G.

2003-01-01

A study on the effects of lateral air entrainment on an upward spreading flame has been conducted. The fuel is a flat PMMA plate of constant length and thickness but variable width. Video images and surface temperatures have allowed establishing the progression of the pyrolyis front and on the flame stand-off distance. These measurements have been incorporated into a theoretical formulation to establish characteristic mass transfer numbers ("B" numbers). The mass transfer number is deemed as a material related parameter that could be used to assess the potential of a material to sustain co-current flame spread. The experimental results show that the theoretical formulation fails to describe heat exchange between the flame and the surface. The discrepancies seem to be associated to lateral air entrainment that lifts the flame off the surface and leads to an over estimation of the local mass transfer number. Particle Image Velocimetry (PIV) measurements are in the process of being acquired. These measurements are intended to provide insight on the effect of air entrainment on the flame stand-off distance. A brief description of the methodology to be followed is presented here.

Modeling of Atmospheric Turbulence as Disturbances for Control Design and Evaluation of High Speed Propulsion Systems

NASA Technical Reports Server (NTRS)

Kopasakis, George

2010-01-01

Atmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying integrated couplings between the propulsion and the vehicle structural dynamics for supersonic vehicles. Models based on the Kolmogorov spectrum have been previously utilized to model atmospheric turbulence. In this paper, a more accurate model is developed in its representative fractional order form, typical of atmospheric disturbances. This is accomplished by first scaling the Kolmogorov spectral to convert them into finite energy von Karman forms. Then a generalized formulation is developed in frequency domain for these scale models that approximates the fractional order with the products of first order transfer functions. Given the parameters describing the conditions of atmospheric disturbances and utilizing the derived formulations, the objective is to directly compute the transfer functions that describe these disturbances for acoustic velocity, temperature, pressure and density. Utilizing these computed transfer functions and choosing the disturbance frequencies of interest, time domain simulations of these representative atmospheric turbulences can be developed. These disturbance representations are then used to first develop considerations for disturbance rejection specifications for the design of the propulsion control system, and then to evaluate the closed-loop performance.

Atmospheric Turbulence Modeling for Aero Vehicles: Fractional Order Fits

NASA Technical Reports Server (NTRS)

Kopasakis, George

2015-01-01

Atmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying coupling between the propulsion and the vehicle structural dynamics for supersonic vehicles. Models based on the Kolmogorov spectrum have been previously utilized to model atmospheric turbulence. In this paper, a more accurate model is developed in its representative fractional order form, typical of atmospheric disturbances. This is accomplished by first scaling the Kolmogorov spectral to convert them into finite energy von Karman forms and then by deriving an explicit fractional circuit-filter type analog for this model. This circuit model is utilized to develop a generalized formulation in frequency domain to approximate the fractional order with the products of first order transfer functions, which enables accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.

Atmospheric Turbulence Modeling for Aero Vehicles: Fractional Order Fits

NASA Technical Reports Server (NTRS)

Kopasakis, George

2010-01-01

Atmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying coupling between the propulsion and the vehicle structural dynamics for supersonic vehicles. Models based on the Kolmogorov spectrum have been previously utilized to model atmospheric turbulence. In this paper, a more accurate model is developed in its representative fractional order form, typical of atmospheric disturbances. This is accomplished by first scaling the Kolmogorov spectral to convert them into finite energy von Karman forms and then by deriving an explicit fractional circuit-filter type analog for this model. This circuit model is utilized to develop a generalized formulation in frequency domain to approximate the fractional order with the products of first order transfer functions, which enables accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.

Tribological properties of graphite-fiber-reinforced, partially fluorinated polyimide composites

NASA Technical Reports Server (NTRS)

Fusaro, R. L.; Hady, W. F.

1985-01-01

Graphite-fiber-reinforced polyimide (GFRPI) composites were formulated from three new partially fluorinated polyimides and three types of graphite fiber. Nine composites were molded into pins and evaluated in a pin-on-disk tribometer. Friction coefficients, wear rates, pin wear surface morphology, and transfer film formation were assessed at 25 and 300 C. Also assessed was the effect of sliding speed on friction. Wear was up to two orders of magnitude lower at 25 C and up to one order of magnitude lower at 300 C than with previously formulated NASA GFRPI composites.

Semiautomated Sample Preparation for Protein Stability and Formulation Screening via Buffer Exchange.

PubMed

Ying, William; Levons, Jaquan K; Carney, Andrea; Gandhi, Rajesh; Vydra, Vicky; Rubin, A Erik

2016-06-01

A novel semiautomated buffer exchange process workflow was developed to enable efficient early protein formulation screening. An antibody fragment protein, BMSdab, was used to demonstrate the workflow. The process afforded 60% to 80% cycle time and scientist time savings and significant material efficiencies. These efficiencies ultimately facilitated execution of this stability work earlier in the drug development process, allowing this tool to inform the developability of potential candidates for development from a formulation perspective. To overcome the key technical challenges, the protein solution was buffer-exchanged by centrifuge filtration into formulations for stability screening in a 96-well plate with an ultrafiltration membrane, leveraging automated liquid handling and acoustic volume measurements to allow several cycles of exchanges. The formulations were transferred into a vacuum manifold and sterile filtered into a rack holding 96 glass vials. The vials were sealed with a capmat of individual caps and placed in stability stations. Stability of the samples prepared by this process and by the standard process was demonstrated to be comparable. This process enabled screening a number of formulations of a protein at an early pharmaceutical development stage with a short sample preparation time. © 2015 Society for Laboratory Automation and Screening.

Dynamically Reconfigurable Approach to Multidisciplinary Problems

NASA Technical Reports Server (NTRS)

Alexandrov, Natalie M.; Lewis, Robert Michael

2003-01-01

The complexity and autonomy of the constituent disciplines and the diversity of the disciplinary data formats make the task of integrating simulations into a multidisciplinary design optimization problem extremely time-consuming and difficult. We propose a dynamically reconfigurable approach to MDO problem formulation wherein an appropriate implementation of the disciplinary information results in basic computational components that can be combined into different MDO problem formulations and solution algorithms, including hybrid strategies, with relative ease. The ability to re-use the computational components is due to the special structure of the MDO problem. We believe that this structure can and should be used to formulate and solve optimization problems in the multidisciplinary context. The present work identifies the basic computational components in several MDO problem formulations and examines the dynamically reconfigurable approach in the context of a popular class of optimization methods. We show that if the disciplinary sensitivity information is implemented in a modular fashion, the transfer of sensitivity information among the formulations under study is straightforward. This enables not only experimentation with a variety of problem formations in a research environment, but also the flexible use of formulations in a production design environment.

Numerical simulation of heat transfer in power law fluid flow through a stenosed artery

NASA Astrophysics Data System (ADS)

Talib, Amira Husni; Abdullah, Ilyani

2017-11-01

A numerical study of heat transfer in a power law fluid is investigated in this paper. The blood flow is treated as power law fluid with a presence of cosine shaped stenosis. This study reveals the effect of stenosis on the heat transfer and velocity of blood flowing in the constricted artery. The governing and energy equations are formulated in a cylindrical coordinate system. Hence, the set of equations and boundary conditions are solved numerically by Marker and Cell (MAC) method. The graphical result shows the profile of blood temperature is increased while the blood velocity is decreased at the critical height of stenosis.

A Corrected Formulation of the Multilayer Model (MLM) for Inferring Gaseous Dry Deposition to Vegetated Surfaces

NASA Technical Reports Server (NTRS)

Saylor, Rick D.; Wolfe, Glenn M.; Meyers, Tilden P.; Hicks, Bruce B.

2014-01-01

The Multilayer Model (MLM) has been used for many years to infer dry deposition fluxes from measured trace species concentrations and standard meteorological measurements for national networks in the U.S., including the U.S. Environmental Protection Agency's Clean Air Status and Trends Network (CASTNet). MLM utilizes a resistance analogy to calculate deposition velocities appropriate for whole vegetative canopies, while employing a multilayer integration to account for vertically varying meteorology, canopy morphology and radiative transfer within the canopy. However, the MLM formulation, as it was originally presented and as it has been subsequently employed, contains a non-physical representation related to the leaf-level quasi-laminar boundary layer resistance that affects the calculation of the total canopy resistance. In this note, the non-physical representation of the canopy resistance as originally formulated in MLM is discussed and a revised, physically consistent, formulation is suggested as a replacement. The revised canopy resistance formulation reduces estimates of HNO3 deposition velocities by as much as 38% during mid-day as compared to values generated by the original formulation. Inferred deposition velocities for SO2 and O3 are not significantly altered by the change in formulation (less than 3%). Inferred deposition loadings of oxidized and total nitrogen from CASTNet data may be reduced by 10-20% and 5-10%, respectively, for the Eastern U. S. when employing the revised formulation of MLM as compared to the original formulation.

A finite element formulation preserving symmetric and banded diffusion stiffness matrix characteristics for fractional differential equations

NASA Astrophysics Data System (ADS)

Lin, Zeng; Wang, Dongdong

2017-10-01

Due to the nonlocal property of the fractional derivative, the finite element analysis of fractional diffusion equation often leads to a dense and non-symmetric stiffness matrix, in contrast to the conventional finite element formulation with a particularly desirable symmetric and banded stiffness matrix structure for the typical diffusion equation. This work first proposes a finite element formulation that preserves the symmetry and banded stiffness matrix characteristics for the fractional diffusion equation. The key point of the proposed formulation is the symmetric weak form construction through introducing a fractional weight function. It turns out that the stiffness part of the present formulation is identical to its counterpart of the finite element method for the conventional diffusion equation and thus the stiffness matrix formulation becomes trivial. Meanwhile, the fractional derivative effect in the discrete formulation is completely transferred to the force vector, which is obviously much easier and efficient to compute than the dense fractional derivative stiffness matrix. Subsequently, it is further shown that for the general fractional advection-diffusion-reaction equation, the symmetric and banded structure can also be maintained for the diffusion stiffness matrix, although the total stiffness matrix is not symmetric in this case. More importantly, it is demonstrated that under certain conditions this symmetric diffusion stiffness matrix formulation is capable of producing very favorable numerical solutions in comparison with the conventional non-symmetric diffusion stiffness matrix finite element formulation. The effectiveness of the proposed methodology is illustrated through a series of numerical examples.

Lithium ion batteries (NMC/graphite) cycling at 80 °C: Different electrolytes and related degradation mechanism

NASA Astrophysics Data System (ADS)

Genieser, R.; Ferrari, S.; Loveridge, M.; Beattie, S. D.; Beanland, R.; Amari, H.; West, G.; Bhagat, R.

2018-01-01

A comprehensive study on high temperature cycling (80 °C) of industrial manufactured Li-ion pouch cells (NMC-111/Graphite) filled with different electrolytes is introduced. Ageing processes such as capacity fade, resistance increase and gas generation are reduced by the choice of appropriate electrolyte formulations. However, even by using additive formulations designed for elevated temperatures a large resistance increase is observed after 200 cycles and more (which does not happen at 55 °C). Symmetrical EIS (Electrochemical Impedance Spectroscopy) shows that the cathodic charge transfer resistance is the main reason for this behaviour. Nonetheless most of the active Li is still available when cycling with suitable additives. No change of the cathode crystalline structure or a growth of the cathodic surface reconstruction layer is observed post cycling at 80 °C. Therefore a disintegration of NMC secondary particles is believed to be the main reason of the cell failure. A separation of single grains is leading to new decomposition and reconstruction layers between primary particles and an increased charge transfer resistance. Further approaches to improve the high temperature cycle stability of NMC based materials should therefore be aimed at the cathode particles morphology in combination with similar electrolyte formulations as used in this study.

Noncontact Infrared-Mediated Heat Transfer During Continuous Freeze-Drying of Unit Doses.

PubMed

Van Bockstal, Pieter-Jan; De Meyer, Laurens; Corver, Jos; Vervaet, Chris; De Beer, Thomas

2017-01-01

Recently, an innovative continuous freeze-drying concept for unit doses was proposed, based on spinning the vials during freezing. An efficient heat transfer during drying is essential to continuously process these spin frozen vials. Therefore, the applicability of noncontact infrared (IR) radiation was examined. The impact of several process and formulation variables on the mass of sublimed ice after 15 min of primary drying (i.e., sublimation rate) and the total drying time was examined. Two experimental designs were performed in which electrical power to the IR heaters, distance between the IR heaters and the spin frozen vial, chamber pressure, product layer thickness, and 5 model formulations were included as factors. A near-infrared spectroscopy method was developed to determine the end point of primary and secondary drying. The sublimation rate was mainly influenced by the electrical power to the IR heaters and the distance between the IR heaters and the vial. The layer thickness had the largest effect on total drying time. The chamber pressure and the 5 model formulations had no significant impact on sublimation rate and total drying time, respectively. This study shows that IR radiation is suitable to provide the energy during the continuous processing of spin frozen vials. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Spin transfer torque in non-collinear magnetic tunnel junctions exhibiting quasiparticle bands: a non-equilibrium Green's function study

NASA Astrophysics Data System (ADS)

Jaya, Selvaraj Mathi

2017-06-01

A non-equilibrium Green's function formulation to study the spin transfer torque (STT) in non-collinear magnetic tunnel junctions (MTJs) exhibiting quasiparticle bands is developed. The formulation can be used to study the magnetoresistance and spin current too. The formulation is used to study the STT in model tunnel junctions exhibiting multiple layers and quasiparticle bands. The many body interaction that gives rise to quasiparticle bands is assumed to be a s - f exchange interaction at the electrode regions of the MTJ. The quasiparticle bands are obtained using a many body procedure and the single particle band structure is obtained using the tight binding model. The bias dependence of the STT as well as the influence of band occupancy and s - f exchange coupling strength on the STT are studied. We find from our studies that the band occupancy plays a significant role in deciding the STT and the s - f interaction strength too influences the STT significantly. Anomalous behavior in both the parallel and perpendicular components of the STT is obtained from our studies. Our results obtained for certain values of the band occupation are found to show the trend observed from the experimental measurements of STT.

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

Shen, Bingyu; Zheng, Liancun, E-mail: liancunzheng@ustb.edu.cn; Chen, Shengting

This paper presents an investigation for magnetohydrodynamic (MHD) viscoelastic fluid boundary layer flow and radiation heat transfer over an unsteady stretching sheet in presence of heat source. Time dependent fractional derivative is first introduced in formulating the boundary layer equations. Numerical solutions are obtained by using the finite difference scheme and L1-algorithm approximation. Results indicate that the proposed model describes a basic delaying times framework for viscoelastic flow and radiation heat transfer. The effects of involved parameters on velocity and temperature fields are shown graphically and analyzed in detail.

Profile shape optimization in multi-jet impingement cooling of dimpled topologies for local heat transfer enhancement

NASA Astrophysics Data System (ADS)

Negi, Deepchand Singh; Pattamatta, Arvind

2015-04-01

The present study deals with shape optimization of dimples on the target surface in multi-jet impingement heat transfer. Bezier polynomial formulation is incorporated to generate profile shapes for the dimple profile generation and a multi-objective optimization is performed. The optimized dimple shape exhibits higher local Nusselt number values compared to the reference hemispherical dimpled plate optimized shape which can be used to alleviate local temperature hot spots on target surface.

Transfer function modeling of damping mechanisms in viscoelastic plates

NASA Technical Reports Server (NTRS)

Slater, J. C.; Inman, D. J.

1991-01-01

This work formulates a method for the modeling of material damping characteristics in plates. The Sophie German equation of classical plate theory is modified to incorporate hysteresis effects represented by complex stiffness using the transfer function approach proposed by Golla and Hughes, (1985). However, this procedure is not limited to this representation. The governing characteristic equation is decoupled through separation of variables, yielding a solution similar to that of undamped classical plate theory, allowing solution of the steady state as well as the transient response problem.

Field Trial of Attenuated Salmonella Typhi Live Oral Vaccine TY21A in Liquid and Enteric-Coated Formulations and Epidemiological Survey for Incidence of Diarrhea due to Shigella Species

DTIC Science & Technology

1989-03-01

and absolute efficacy of three doses of Ty2la vaccine given in enteric-coated capsule or liquid formulation. Intensive clinical and bacteriologic...TABLES Table 1. Evaluation of the efficacy of three doses of the enteric-coated capsule formulation of Ty2la live oral vaccine given within one week in...November, 1986 thzough February, 1989 of a field trial in Area Sur Oriente and Area Norte assessing the efficacy of Ty21a vaccine in liquid or enteric

Fundamentals of freeze-drying.

PubMed

Nail, Steven L; Jiang, Shan; Chongprasert, Suchart; Knopp, Shawn A

2002-01-01

Given the increasing importance of reducing development time for new pharmaceutical products, formulation and process development scientists must continually look for ways to "work smarter, not harder." Within the product development arena, this means reducing the amount of trial and error empiricism in arriving at a formulation and identification of processing conditions which will result in a quality final dosage form. Characterization of the freezing behavior of the intended formulation is necessary for developing processing conditions which will result in the shortest drying time while maintaining all critical quality attributes of the freeze-dried product. Analysis of frozen systems was discussed in detail, particularly with respect to the glass transition as the physical event underlying collapse during freeze-drying, eutectic mixture formation, and crystallization events upon warming of frozen systems. Experiments to determine how freezing and freeze-drying behavior is affected by changes in the composition of the formulation are often useful in establishing the "robustness" of a formulation. It is not uncommon for seemingly subtle changes in composition of the formulation, such as a change in formulation pH, buffer salt, drug concentration, or an additional excipient, to result in striking differences in freezing and freeze-drying behavior. With regard to selecting a formulation, it is wise to keep the formulation as simple as possible. If a buffer is needed, a minimum concentration should be used. The same principle applies to added salts: If used at all, the concentration should be kept to a minimum. For many proteins a combination of an amorphous excipient, such as a disaccharide, and a crystallizing excipient, such as glycine, will result in a suitable combination of chemical stability and physical stability of the freeze-dried solid. Concepts of heat and mass transfer are valuable in rational design of processing conditions. Heat transfer by conduction--the dominant mechanism of heat transfer in freeze-drying--is inefficient at the pressures used in freeze-drying. Steps should be taken to improve the thermal contact between the product and the shelf of the freeze dryer, such as eliminating metal trays from the drying process. Quantitation of the heat transfer coefficient for the geometry used is a useful way of assessing the impact of changes in the system such as elimination of product trays and changes in the vial. Because heat transfer by conduction through the vapor increases with increasing pressure, the commonly held point of view that "the lower the pressure, the better" is not true with respect to process efficiency. The optimum pressure for a given product is a function of the temperature at which freeze-drying is carried out, and lower pressures are needed at low product temperatures. The controlling resistance to mass transfer is almost always the resistance of the partially dried solids above the submination interface. This resistance can be minimized by avoiding fill volumes of more than about half the volume of the container. The development scientist should also recognize that very high concentrations of solute may not be appropriate for optimum freeze-drying, particularly if the resistance of the dried product layer increases sharply with concentration. Although the last 10 years has seen the publication of a significant body of literature of great value in allowing development scientists and engineers to "work smarter," there is still much work needed in both the science and the technology of freeze-drying. Scientific development is needed for improving analytical methodology for characterization of frozen systems and freeze-dried solids. A better understanding of the relationship between molecular mobility and reactivity is needed to allow accurate prediction of product stability at the intended storage temperature based on accelerated stability at higher temperatures. This requires that the temperature dependence of glass transition-associated mobility, particularly at temperatures below the glass transition, be studied in greater depth. The relevance of the concept of strong and fragile glasses to frozen systems and freeze-dried solids has only begun to be explored. The list of pharmaceutically acceptable protective solutes is very short, and more imagination--and work--is needed in order to develop pharmaceutically acceptable alternative stabilizers. There is a need for technology development in process monitoring, particularly in developing a way to measure the status of the product during freezing and freeze-drying without placing temperature measurement probes in individual vials of product. The current practice of placing thermocouples in vials is uncertain with respect to reliability of the data, inconsistent with elimination of personnel in close proximity to open vials of product in an aseptic environment, and incompatible with technology for automatic material handling in freeze-drying. In addition, a method for controlling the degree of supercooling during freezing would allow better control of freezing rate and would, in many cases, result in more consistent product quality.

Heat transfer in rocket engine combustion chambers and regeneratively cooled nozzles

NASA Technical Reports Server (NTRS)

1993-01-01

A conjugate heat transfer computational fluid dynamics (CFD) model to describe regenerative cooling in the main combustion chamber and nozzle and in the injector faceplate region for a launch vehicle class liquid rocket engine was developed. An injector model for sprays which treats the fluid as a variable density, single-phase media was formulated, incorporated into a version of the FDNS code, and used to simulate the injector flow typical of that in the Space Shuttle Main Engine (SSME). Various chamber related heat transfer analyses were made to verify the predictive capability of the conjugate heat transfer analysis provided by the FDNS code. The density based version of the FDNS code with the real fluid property models developed was successful in predicting the streamtube combustion of individual injector elements.

Nonlinear feedback guidance law for aero-assisted orbit transfer maneuvers

NASA Technical Reports Server (NTRS)

Menon, P. K. A.

1992-01-01

Aero-assisted orbit transfer vehicles have the potential for significantly reducing the fuel requirements in certain classes of orbit transfer operations. Development of a nonlinear feedback guidance law for performing aero-assisted maneuvers that accomplish simultaneous change of all the orbital elements with least vehicle acceleration magnitude is discussed. The analysis is based on a sixth order nonlinear point-mass vehicle model with lift, bank angle, thrust and drag modulation as the control variables. The guidance law uses detailed vehicle aerodynamic and the atmosphere models in the feedback loop. Higher-order gravitational harmonics, planetary atmosphere rotation and ambient winds are included in the formulation. Due to modest computational requirements, the guidance law is implementable on-board an orbit transfer vehicle. The guidance performance is illustrated for three sets of boundary conditions.

A facile alternative technique for large-area graphene transfer via sacrificial polymer

DOE PAGES

Auchter, Eric; Marquez, Justin; Yarbro, Stephen L.; ...

2017-12-07

A novel method of transferring large-area graphene sheets onto a variety of substrates using Formvar (polyvinyl formal) is presented. Due to the ease at which formvar can be dissolved in chloroform this method allows for a consistent, a clean, and a more rapid transfer than other techniques including the PMMA assisted one. This novel transfer method is demonstrated by transferring large-area graphene onto a range of substrates including commercial TEM grids, silicon dioxide and glass. Raman spectroscopy was used to confirm the presence of graphene and characterize the morphological properties of the large-area sheets. SEM and AFM analyses demonstrated themore » effectiveness of our rapid transfer technique for clean crystalline large-area graphene sheets. The removal of the sacrificial polymer was found to be one to two orders of magnitude faster than PMMA methods. Ultimately this facile transfer technique offers new opportunities for a wide range of applications for large-area graphene through the utilization of a new sacrificial polymer.« less

A facile alternative technique for large-area graphene transfer via sacrificial polymer

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

Auchter, Eric; Marquez, Justin; Yarbro, Stephen L.

A novel method of transferring large-area graphene sheets onto a variety of substrates using Formvar (polyvinyl formal) is presented. Due to the ease at which formvar can be dissolved in chloroform this method allows for a consistent, a clean, and a more rapid transfer than other techniques including the PMMA assisted one. This novel transfer method is demonstrated by transferring large-area graphene onto a range of substrates including commercial TEM grids, silicon dioxide and glass. Raman spectroscopy was used to confirm the presence of graphene and characterize the morphological properties of the large-area sheets. SEM and AFM analyses demonstrated themore » effectiveness of our rapid transfer technique for clean crystalline large-area graphene sheets. The removal of the sacrificial polymer was found to be one to two orders of magnitude faster than PMMA methods. Ultimately this facile transfer technique offers new opportunities for a wide range of applications for large-area graphene through the utilization of a new sacrificial polymer.« less

Analysis of the interface and data transfer from ICU to normal wards in a German University Hospital.

PubMed

Vollmer, Anne-Maria; Skonetzki-Cheng, Stefan; Prokosch, Hans-Ulrich

2013-01-01

Typically general wards and intensive care units (ICU) have very different labor organizations, structures and IT-systems in Germany. There is a need for coordination, because of the different working arrangements. Our team investigated the interface between ICU and general ward and especially the respective information transfer in the University hospital in Erlangen (Bavaria, Germany). The research team used a combination of interviews, observations and the analysis of transfer records and forms as part of a methodical triangulation. We identified 41 topics, which are discussed or presented in writing during the handover. In a second step, we investigate the requirements of data transmission in expert interviews. A data transfer concept from the perspective of the nurses and physicians was developed and we formulated recommendations for improvements of process and communication for this interface. Finally the data transfer concept was evaluated by the respondents.

Interference of interchromophoric energy-transfer pathways in π-conjugated macrocycles

DOE PAGES

Alfonso Hernandez, Laura; Nelson, Tammie Renee; Gelin, Maxim F.; ...

2016-11-10

The interchromophoric energy-transfer pathways between weakly coupled units in a π-conjugated phenylene–ethynylene macrocycle and its half-ring analogue have been investigated using the nonadiabatic excited-state molecular dynamics approach. To track the flow of electronic transition density between macrocycle units, we formulate a transition density flux analysis adapted from the statistical minimum flow method previously developed to investigate vibrational energy flow. Following photoexcitation, transition density is primarily delocalized on two chromophore units and the system undergoes ultrafast energy transfer, creating a localized excited state on a single unit. In the macrocycle, distinct chromophore units donate transition density to a single acceptor unitmore » but do not interchange transition density among each other. We find that energy transfer in the macrocycle is slower than in the corresponding half ring because of the presence of multiple interfering energy-transfer pathways. Finally, simulation results are validated by modeling the fluorescence anisotropy decay.« less

Momentum transfer conduits -- A new microscopic look at porous media

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

Moaveni, S.

In this paper, the flow of fluid through porous media is investigated on a microscopic scale by representing a porous medium by an assemblage of hypothetical conduits through which the fluid momentum is transferred across the medium. It is shown that the rate of transfer of fluid momentum depends on the geometrical structure of the conduits such as the number density of momentum transfer conduits (MTCs), the length distribution and the directional distribution of these hypothetical conduits. In addition an expression for the total number of momentum transfer conduits reaching an arbitrary areal element is developed. Finally, an average heightmore » normal to an arbitrary areal element at which the MTCs were last discharged is formulated. This idea leads to definition of momentum thickness, which in turn may be used to define an effective (pseudo) viscosity for a given porous medium.« less

Dexter energy transfer pathways

PubMed Central

Skourtis, Spiros S.; Liu, Chaoren; Antoniou, Panayiotis; Virshup, Aaron M.; Beratan, David N.

2016-01-01

Energy transfer with an associated spin change of the donor and acceptor, Dexter energy transfer, is critically important in solar energy harvesting assemblies, damage protection schemes of photobiology, and organometallic opto-electronic materials. Dexter transfer between chemically linked donors and acceptors is bridge mediated, presenting an enticing analogy with bridge-mediated electron and hole transfer. However, Dexter coupling pathways must convey both an electron and a hole from donor to acceptor, and this adds considerable richness to the mediation process. We dissect the bridge-mediated Dexter coupling mechanisms and formulate a theory for triplet energy transfer coupling pathways. Virtual donor–acceptor charge-transfer exciton intermediates dominate at shorter distances or higher tunneling energy gaps, whereas virtual intermediates with an electron and a hole both on the bridge (virtual bridge excitons) dominate for longer distances or lower energy gaps. The effects of virtual bridge excitons were neglected in earlier treatments. The two-particle pathway framework developed here shows how Dexter energy-transfer rates depend on donor, bridge, and acceptor energetics, as well as on orbital symmetry and quantum interference among pathways. PMID:27382185

Dexter energy transfer pathways.

PubMed

Skourtis, Spiros S; Liu, Chaoren; Antoniou, Panayiotis; Virshup, Aaron M; Beratan, David N

2016-07-19

Energy transfer with an associated spin change of the donor and acceptor, Dexter energy transfer, is critically important in solar energy harvesting assemblies, damage protection schemes of photobiology, and organometallic opto-electronic materials. Dexter transfer between chemically linked donors and acceptors is bridge mediated, presenting an enticing analogy with bridge-mediated electron and hole transfer. However, Dexter coupling pathways must convey both an electron and a hole from donor to acceptor, and this adds considerable richness to the mediation process. We dissect the bridge-mediated Dexter coupling mechanisms and formulate a theory for triplet energy transfer coupling pathways. Virtual donor-acceptor charge-transfer exciton intermediates dominate at shorter distances or higher tunneling energy gaps, whereas virtual intermediates with an electron and a hole both on the bridge (virtual bridge excitons) dominate for longer distances or lower energy gaps. The effects of virtual bridge excitons were neglected in earlier treatments. The two-particle pathway framework developed here shows how Dexter energy-transfer rates depend on donor, bridge, and acceptor energetics, as well as on orbital symmetry and quantum interference among pathways.

75 FR 21634 - Government-Owned Inventions; Availability for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-26

... such as cutaneous T-cell lymphoma (CTCL) and skin disorders such as lupus, contact dermatitis, and drug... result in contact dermatitis, exanthematous reactions, and photoallergic reactions. A topical formulation... the indicated licensing contact at the Office of Technology Transfer, National Institutes of Health...

Asymmetric Base-Bleed Effect on Aerospike Plume-Induced Base-Heating Environment

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Droege, Alan; DAgostino, Mark; Lee, Young-Ching; Williams, Robert

2004-01-01

A computational heat transfer design methodology was developed to study the dual-engine linear aerospike plume-induced base-heating environment during one power-pack out, in ascent flight. It includes a three-dimensional, finite volume, viscous, chemically reacting, and pressure-based computational fluid dynamics formulation, a special base-bleed boundary condition, and a three-dimensional, finite volume, and spectral-line-based weighted-sum-of-gray-gases absorption computational radiation heat transfer formulation. A separate radiation model was used for diagnostic purposes. The computational methodology was systematically benchmarked. In this study, near-base radiative heat fluxes were computed, and they compared well with those measured during static linear aerospike engine tests. The base-heating environment of 18 trajectory points selected from three power-pack out scenarios was computed. The computed asymmetric base-heating physics were analyzed. The power-pack out condition has the most impact on convective base heating when it happens early in flight. The source of its impact comes from the asymmetric and reduced base bleed.

Numerical simulation of mushrooms during freezing using the FEM and an enthalpy: Kirchhoff formulation

NASA Astrophysics Data System (ADS)

Santos, M. V.; Lespinard, A. R.

2011-12-01

The shelf life of mushrooms is very limited since they are susceptible to physical and microbial attack; therefore they are usually blanched and immediately frozen for commercial purposes. The aim of this work was to develop a numerical model using the finite element technique to predict freezing times of mushrooms considering the actual shape of the product. The original heat transfer equation was reformulated using a combined enthalpy-Kirchhoff formulation, therefore an own computational program using Matlab 6.5 (MathWorks, Natick, Massachusetts) was developed, considering the difficulties encountered when simulating this non-linear problem in commercial softwares. Digital images were used to generate the irregular contour and the domain discretization. The numerical predictions agreed with the experimental time-temperature curves during freezing of mushrooms (maximum absolute error <3.2°C) obtaining accurate results and minimum computer processing times. The codes were then applied to determine required processing times for different operating conditions (external fluid temperatures and surface heat transfer coefficients).

Multi-scale modeling of urban air pollution: development of a Street-in-Grid model

NASA Astrophysics Data System (ADS)

Kim, Youngseob; Wu, You; Seigneur, Christian; Roustan, Yelva

2016-04-01

A new multi-scale model of urban air pollution is presented. This model combines a chemical-transport model (CTM) that includes a comprehensive treatment of atmospheric chemistry and transport at spatial scales greater than 1 km and a street-network model that describes the atmospheric concentrations of pollutants in an urban street network. The street-network model is based on the general formulation of the SIRANE model and consists of two main components: a street-canyon component and a street-intersection component. The street-canyon component calculates the mass transfer velocity at the top of the street canyon (roof top) and the mean wind velocity within the street canyon. The estimation of the mass transfer velocity depends on the intensity of the standard deviation of the vertical velocity at roof top. The effect of various formulations of this mass transfer velocity on the pollutant transport at roof-top level is examined. The street-intersection component calculates the mass transfer from a given street to other streets across the intersection. These mass transfer rates among the streets are calculated using the mean wind velocity calculated for each street and are balanced so that the total incoming flow rate is equal to the total outgoing flow rate from the intersection including the flow between the intersection and the overlying atmosphere at roof top. In the default option, the Leighton photostationary cycle among ozone (O3) and nitrogen oxides (NO and NO2) is used to represent the chemical reactions within the street network. However, the influence of volatile organic compounds (VOC) on the pollutant concentrations increases when the nitrogen oxides (NOx) concentrations are low. To account for the possible VOC influence on street-canyon chemistry, the CB05 chemical kinetic mechanism, which includes 35 VOC model species, is implemented in this street-network model. A sensitivity study is conducted to assess the uncertainties associated with the use of the Leighton cycle chemistry. The street-network model is coupled to the CTM Polair3D of the Polyphemus air quality modeling platform to constitute a Street-in-Grid (SinG) model. The street-network model is used to simulate the concentrations of the chemical species in the lowest layer in the urban area and the simulation for the upper layers is then performed by Polair3D. Interactions between the street-network model and the host CTM occur at roof-top and depend on the vertical mass transfer described above. The SinG model is used to simulate the concentrations of gas-phase pollutants (O3 and NOx) in a Paris suburb. The emission data for each street that are needed for the street-network model were obtained from a dynamic traffic model. Topographic data, such as street length/width and building height, were obtained from a geographic database (BD TOPO). Simulated concentrations are compared to concentrations measured at two monitoring stations that were located on each side of a large avenue.

Aerospace technology and commercial nuclear power; Proceedings of the Workshop Conference, Williamsburg, VA, November 18-20, 1981

NASA Technical Reports Server (NTRS)

Grey, J. (Editor)

1982-01-01

An attempt has been made to compare the technologies, institutions and procedures of the aerospace and commercial nuclear power industries, in order to characterize similarities and contrasts as well as to identify the most fruitful means by which to transfer information, technology, and procedures between the two industries. The seven working groups involved in this study took as their topics powerplant design formulation and effectiveness, plant safety and operations, powerplant control technology and integration, economic and financial analyses, public relations, and the management of nuclear waste and spent fuel. Consequential differences are noted between the two industries in matters of certification and licencing procedures, assignment of responsibility for both safety and financial performance, and public viewpoint. Areas for beneficial interaction include systems management and control and safety system technology. No individual items are abstracted in this volume

Assisted reproduction with gametes and embryos: what research is needed and fundable?

PubMed

Seidel, George E

2016-01-01

Principles for selecting future research projects include interests of investigators, fundability, potential applications, ethical considerations, being able to formulate testable hypotheses and choosing the best models, including selection of the most appropriate species. The following 10 areas of assisted reproduction seem especially appropriate for further research: efficacious capacitation of bovine spermatozoa in vitro; improved in vitro bovine oocyte maturation; decreasing variability and increasing efficacy of bovine superovulation; improved fertility of sexed semen; improving equine IVF; improving cryopreservation of rooster spermatozoa; understanding differences between males in success of sperm cryopreservation and reasons for success in competitive fertilisation; mechanisms of reprogramming somatic cell nuclei after nuclear transfer; regulation of differentiation of ovarian primordial follicles; and means by which spermatozoa maintain fertility during storage in the epididymis. Issues are species specific for several of these topics, in most cases because the biology is species specific.

Clinical Case Studies in Psychoanalytic and Psychodynamic Treatment

PubMed Central

Willemsen, Jochem; Della Rosa, Elena; Kegerreis, Sue

2017-01-01

This manuscript provides a review of the clinical case study within the field of psychoanalytic and psychodynamic treatment. The method has been contested for methodological reasons and because it would contribute to theoretical pluralism in the field. We summarize how the case study method is being applied in different schools of psychoanalysis, and we clarify the unique strengths of this method and areas for improvement. Finally, based on the literature and on our own experience with case study research, we come to formulate nine guidelines for future case study authors: (1) basic information to include, (2) clarification of the motivation to select a particular patient, (3) information about informed consent and disguise, (4) patient background and context of referral or self-referral, (5) patient's narrative, therapist's observations and interpretations, (6) interpretative heuristics, (7) reflexivity and counter-transference, (8) leaving room for interpretation, and (9) answering the research question, and comparison with other cases. PMID:28210235

Critical length scale controls adhesive wear mechanisms

PubMed Central

Aghababaei, Ramin; Warner, Derek H.; Molinari, Jean-Francois

2016-01-01

The adhesive wear process remains one of the least understood areas of mechanics. While it has long been established that adhesive wear is a direct result of contacting surface asperities, an agreed upon understanding of how contacting asperities lead to wear debris particle has remained elusive. This has restricted adhesive wear prediction to empirical models with limited transferability. Here we show that discrepant observations and predictions of two distinct adhesive wear mechanisms can be reconciled into a unified framework. Using atomistic simulations with model interatomic potentials, we reveal a transition in the asperity wear mechanism when contact junctions fall below a critical length scale. A simple analytic model is formulated to predict the transition in both the simulation results and experiments. This new understanding may help expand use of computer modelling to explore adhesive wear processes and to advance physics-based wear laws without empirical coefficients. PMID:27264270

A report from the pediatric formulations task force: perspectives on the state of child-friendly oral dosage forms.

PubMed

Zajicek, Anne; Fossler, Michael J; Barrett, Jeffrey S; Worthington, Jeffrey H; Ternik, Robert; Charkoftaki, Georgia; Lum, Susan; Breitkreutz, Jörg; Baltezor, Mike; Macheras, Panos; Khan, Mansoor; Agharkar, Shreeram; MacLaren, David Douglas

2013-10-01

Despite the fact that a significant percentage of the population is unable to swallow tablets and capsules, these dosage forms continue to be the default standard. These oral formulations fail many patients, especially children, because of large tablet or capsule size, poor palatability, and lack of correct dosage strength. The clinical result is often lack of adherence and therapeutic failure. The American Association of Pharmaceutical Scientists formed a Pediatric Formulations Task Force, consisting of members with various areas of expertise including pediatrics, formulation development, clinical pharmacology, and regulatory science, in order to identify pediatric, manufacturing, and regulatory issues and areas of needed research and regulatory guidance. Dosage form and palatability standards for all pediatric ages, relative bioavailability requirements, and small batch manufacturing capabilities and creation of a viable economic model were identified as particular needs. This assessment is considered an important first step for a task force seeking creative approaches to providing more appropriate oral formulations for children.

Modeling human target acquisition in ground-to-air weapon systems

NASA Technical Reports Server (NTRS)

Phatak, A. V.; Mohr, R. L.; Vikmanis, M.; Wei, K. C.

1982-01-01

The problems associated with formulating and validating mathematical models for describing and predicting human target acquisition response are considered. In particular, the extension of the human observer model to include the acquisition phase as well as the tracking segment is presented. Relationship of the Observer model structure to the more complex Standard Optimal Control model formulation and to the simpler Transfer Function/Noise representation is discussed. Problems pertinent to structural identifiability and the form of the parameterization are elucidated. A systematic approach toward the identification of the observer acquisition model parameters from ensemble tracking error data is presented.

A methodology for optimal MSW management, with an application in the waste transportation of Attica Region, Greece.

PubMed

Economopoulou, M A; Economopoulou, A A; Economopoulos, A P

2013-11-01

The paper describes a software system capable of formulating alternative optimal Municipal Solid Wastes (MSWs) management plans, each of which meets a set of constraints that may reflect selected objections and/or wishes of local communities. The objective function to be minimized in each plan is the sum of the annualized capital investment and annual operating cost of all transportation, treatment and final disposal operations involved, taking into consideration the possible income from the sale of products and any other financial incentives or disincentives that may exist. For each plan formulated, the system generates several reports that define the plan, analyze its cost elements and yield an indicative profile of selected types of installations, as well as data files that facilitate the geographic representation of the optimal solution in maps through the use of GIS. A number of these reports compare the technical and economic data from all scenarios considered at the study area, municipality and installation level constituting in effect sensitivity analysis. The generation of alternative plans offers local authorities the opportunity of choice and the results of the sensitivity analysis allow them to choose wisely and with consensus. The paper presents also an application of this software system in the capital Region of Attica in Greece, for the purpose of developing an optimal waste transportation system in line with its approved waste management plan. The formulated plan was able to: (a) serve 113 Municipalities and Communities that generate nearly 2 milliont/y of comingled MSW with distinctly different waste collection patterns, (b) take into consideration several existing waste transfer stations (WTS) and optimize their use within the overall plan, (c) select the most appropriate sites among the potentially suitable (new and in use) ones, (d) generate the optimal profile of each WTS proposed, and (e) perform sensitivity analysis so as to define the impact of selected sets of constraints (limitations in the availability of sites and in the capacity of their installations) on the design and cost of the ensuing optimal waste transfer system. The results show that optimal planning offers significant economic savings to municipalities, while reducing at the same time the present levels of traffic, fuel consumptions and air emissions in the congested Athens basin. Copyright © 2013 Elsevier Ltd. All rights reserved.

Decontamination formulations for disinfection and sterilization

DOEpatents

Tucker, Mark D.; Engler, Daniel E.

2007-09-18

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

Physics of Canopy Boundary Layer Resistance for Better Quantification of Sensitivity of Deforestation Scenarios

NASA Astrophysics Data System (ADS)

Ragi, K. B.; Patel, R.

2015-12-01

A great deal of studies focused on deforestation scenarios in the tropical rainforests. Though all these efforts are useful in the understanding of its response to climate, the systematic understanding of uncertainties in representation of physical processes related to vegetation through sensitivity studies is imperative antecedently to understand the real role of vegetation in changing the climate. It is understood that the dense vegetation fluxes energy and moisture to the atmosphere. But, how much a specific process/a group of processes in the surface conditions of a specific area helps flux energy, moisture and tracers is unknown due to lack of process sensitivity studies and uncertain due to malfunctioning of processes. In this presentation, we have found a faulty parameterization, through process sensitivity studies, that would abet in energy and moisture fluxes to the atmosphere. The model we have employed is the Common Land Model2014. The area we have chosen is the Congolese rainforest. We have discovered the flaw in the leaf boundary layer resistance (LBLR), through sensitivity studies in the LSMs, especially in the dense forest regions. This LBLR is over-parameterized with constant heat transfer coefficient and characteristic dimension of leaves; and friction velocity. However, it is too scant because of overlooking of significant complex physics of turbulence and canopy roughness boundary layer to function it realistically. Our sensitivity results show the deficiency of this process and we have formulated canopy boundary layer resistance, instead of LBLR, with depending variables such as LAI, roughness length, vegetation temperature using appropriate thermo-fluid dynamical principles. We are running the sensitivity experiments with new formulations for setting the parameter values for the data not available so far. This effort would lead to better physics for the land-use change studies and demand for the retrieval of new parameters from satellite/field experiments such as leaf mass per area and specific heat capacity of vegetation.

Soret and Dufour effects on MHD peristaltic flow of Prandtl fluid in a rotating channel

NASA Astrophysics Data System (ADS)

Hayat, Tasawar; Zahir, Hina; Tanveer, Anum; Alsaedi, Ahmed

2018-03-01

An analysis has been arranged to study the magnetohydrodynamics (MHD) peristaltic flow of Prandtl fluid in a channel with flexible walls. Both fluid and channel are in a state of solid body rotation. Simultaneous effects of heat and mass transfer with thermal-diffusion (Soret) and diffusion-thermo (Dufour) effects are considered. Convective conditions for heat and mass transfer in the formulation are adopted. Ordinary differential systems using low Reynolds number and long wavelength approximation are obtained. Resulting equations have been solved numerically. The discussion of axial and secondary velocities, temperature, concentration and heat transfer coefficient with respect to emerging parameters embedded in the flow model is presented after sketching plots.

Modelling charge transfer reactions with the frozen density embedding formalism.

PubMed

Pavanello, Michele; Neugebauer, Johannes

2011-12-21

The frozen density embedding (FDE) subsystem formulation of density-functional theory is a useful tool for studying charge transfer reactions. In this work charge-localized, diabatic states are generated directly with FDE and used to calculate electronic couplings of hole transfer reactions in two π-stacked nucleobase dimers of B-DNA: 5'-GG-3' and 5'-GT-3'. The calculations rely on two assumptions: the two-state model, and a small differential overlap between donor and acceptor subsystem densities. The resulting electronic couplings agree well with benchmark values for those exchange-correlation functionals that contain a high percentage of exact exchange. Instead, when semilocal GGA functionals are used the electronic couplings are grossly overestimated.

Mathematical simulation of convective-radiative heat transfer in a ventilated rectangular cavity with consideration of internal mass transfer

NASA Astrophysics Data System (ADS)

Sheremet, M. A.; Shishkin, N. I.

2012-07-01

Mathematical simulation of the nonstationary regimes of heat-and-mass transfer in a ventilated rectangular cavity with heat-conducting walls of finite thickness in the presence of a heat-generating element of constant temperature has been carried out with account for the radiative heat transfer in the Rosseland approximation. As mechanisms of energy transfer in this cavity, the combined convection and the thermal radiation in the gas space of the cavity and the heat conduction in the elements of its fencing solid shell were considered. The mathematical model formulated in the dimensionless stream function-vorticity vector-temperature-concentration variables was realized numerically with the use of the finite-difference method. The streamline, temperature-field, and concentration distributions reflecting the influence of the Rayleigh number (Ra = 104, 105, 106), the nonstationarity (0 < τ ≤ 1000), and the optical thickness of the medium (τλ = 50, 100, 200) on the regimes of the gas flow and the heat-and-mass transfer in the cavity have been obtained.

Quality by design: optimization of a freeze-drying cycle via design space in case of heterogeneous drying behavior and influence of the freezing protocol.

PubMed

Pisano, Roberto; Fissore, Davide; Barresi, Antonello A; Brayard, Philippe; Chouvenc, Pierre; Woinet, Bertrand

2013-02-01

This paper shows how to optimize the primary drying phase, for both product quality and drying time, of a parenteral formulation via design space. A non-steady state model, parameterized with experimentally determined heat and mass transfer coefficients, is used to define the design space when the heat transfer coefficient varies with the position of the vial in the array. The calculations recognize both equipment and product constraints, and also take into account model parameter uncertainty. Examples are given of cycles designed for the same formulation, but varying the freezing conditions and the freeze-dryer scale. These are then compared in terms of drying time. Furthermore, the impact of inter-vial variability on design space, and therefore on the optimized cycle, is addressed. With this regard, a simplified method is presented for the cycle design, which reduces the experimental effort required for the system qualification. The use of mathematical modeling is demonstrated to be very effective not only for cycle development, but also for solving problem of process transfer. This study showed that inter-vial variability remains significant when vials are loaded on plastic trays, and how inter-vial variability can be taken into account during process design.

Impediments to predicting site response: Seismic property estimation and modeling simplifications

USGS Publications Warehouse

Thompson, E.M.; Baise, L.G.; Kayen, R.E.; Guzina, B.B.

2009-01-01

We compare estimates of the empirical transfer function (ETF) to the plane SH-wave theoretical transfer function (TTF) within a laterally constant medium for invasive and noninvasive estimates of the seismic shear-wave slownesses at 13 Kiban-Kyoshin network stations throughout Japan. The difference between the ETF and either of the TTFs is substantially larger than the difference between the two TTFs computed from different estimates of the seismic properties. We show that the plane SH-wave TTF through a laterally homogeneous medium at vertical incidence inadequately models observed amplifications at most sites for both slowness estimates, obtained via downhole measurements and the spectral analysis of surface waves. Strategies to improve the predictions can be separated into two broad categories: improving the measurement of soil properties and improving the theory that maps the 1D soil profile onto spectral amplification. Using an example site where the 1D plane SH-wave formulation poorly predicts the ETF, we find a more satisfactory fit to the ETF by modeling the full wavefield and incorporating spatially correlated variability of the seismic properties. We conclude that our ability to model the observed site response transfer function is limited largely by the assumptions of the theoretical formulation rather than the uncertainty of the soil property estimates.

Large eddy simulation of rotating turbulent flows and heat transfer by the lattice Boltzmann method

NASA Astrophysics Data System (ADS)

Liou, Tong-Miin; Wang, Chun-Sheng

2018-01-01

Due to its advantage in parallel efficiency and wall treatment over conventional Navier-Stokes equation-based methods, the lattice Boltzmann method (LBM) has emerged as an efficient tool in simulating turbulent heat and fluid flows. To properly simulate the rotating turbulent flow and heat transfer, which plays a pivotal role in tremendous engineering devices such as gas turbines, wind turbines, centrifugal compressors, and rotary machines, the lattice Boltzmann equations must be reformulated in a rotating coordinate. In this study, a single-rotating reference frame (SRF) formulation of the Boltzmann equations is newly proposed combined with a subgrid scale model for the large eddy simulation of rotating turbulent flows and heat transfer. The subgrid scale closure is modeled by a shear-improved Smagorinsky model. Since the strain rates are also locally determined by the non-equilibrium part of the distribution function, the calculation process is entirely local. The pressure-driven turbulent channel flow with spanwise rotation and heat transfer is used for validating the approach. The Reynolds number characterized by the friction velocity and channel half height is fixed at 194, whereas the rotation number in terms of the friction velocity and channel height ranges from 0 to 3.0. A working fluid of air is chosen, which corresponds to a Prandtl number of 0.71. Calculated results are demonstrated in terms of mean velocity, Reynolds stress, root mean square (RMS) velocity fluctuations, mean temperature, RMS temperature fluctuations, and turbulent heat flux. Good agreement is found between the present LBM predictions and previous direct numerical simulation data obtained by solving the conventional Navier-Stokes equations, which confirms the capability of the proposed SRF LBM and subgrid scale relaxation time formulation for the computation of rotating turbulent flows and heat transfer.

An integrated process analytical technology (PAT) approach to monitoring the effect of supercooling on lyophilization product and process parameters of model monoclonal antibody formulations.

PubMed

Awotwe Otoo, David; Agarabi, Cyrus; Khan, Mansoor A

2014-07-01

The aim of the present study was to apply an integrated process analytical technology (PAT) approach to control and monitor the effect of the degree of supercooling on critical process and product parameters of a lyophilization cycle. Two concentrations of a mAb formulation were used as models for lyophilization. ControLyo™ technology was applied to control the onset of ice nucleation, whereas tunable diode laser absorption spectroscopy (TDLAS) was utilized as a noninvasive tool for the inline monitoring of the water vapor concentration and vapor flow velocity in the spool during primary drying. The instantaneous measurements were then used to determine the effect of the degree of supercooling on critical process and product parameters. Controlled nucleation resulted in uniform nucleation at lower degrees of supercooling for both formulations, higher sublimation rates, lower mass transfer resistance, lower product temperatures at the sublimation interface, and shorter primary drying times compared with the conventional shelf-ramped freezing. Controlled nucleation also resulted in lyophilized cakes with more elegant and porous structure with no visible collapse or shrinkage, lower specific surface area, and shorter reconstitution times compared with the uncontrolled nucleation. Uncontrolled nucleation however resulted in lyophilized cakes with relatively lower residual moisture contents compared with controlled nucleation. TDLAS proved to be an efficient tool to determine the endpoint of primary drying. There was good agreement between data obtained from TDLAS-based measurements and SMART™ technology. ControLyo™ technology and TDLAS showed great potential as PAT tools to achieve enhanced process monitoring and control during lyophilization cycles. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Spatial transferability of habitat suitability models of Nephrops norvegicus among fished areas in the Northeast Atlantic: sufficiently stable for marine resource conservation?

PubMed

Lauria, Valentina; Power, Anne Marie; Lordan, Colm; Weetman, Adrian; Johnson, Mark P

2015-01-01

Knowledge of the spatial distribution and habitat associations of species in relation to the environment is essential for their management and conservation. Habitat suitability models are useful in quantifying species-environment relationships and predicting species distribution patterns. Little is known, however, about the stability and performance of habitat suitability models when projected into new areas (spatial transferability) and how this can inform resource management. The aims of this study were to model habitat suitability of Norway lobster (Nephrops norvegicus) in five fished areas of the Northeast Atlantic (Aran ground, Irish Sea, Celtic Sea, Scotland Inshore and Fladen ground), and to test for spatial transferability of habitat models among multiple regions. Nephrops burrow density was modelled using generalised additive models (GAMs) with predictors selected from four environmental variables (depth, slope, sediment and rugosity). Models were evaluated and tested for spatial transferability among areas. The optimum models (lowest AICc) for different areas always included depth and sediment as predictors. Burrow densities were generally greater at depth and in finer sediments, but relationships for individual areas were sometimes more complex. Aside from an inclusion of depth and sediment, the optimum models differed between fished areas. When it came to tests of spatial transferability, however, most of the models were able to predict Nephrops density in other areas. Furthermore, transferability was not dependent on use of the optimum models since competing models were also able to achieve a similar level of transferability to new areas. A degree of decoupling between model 'fitting' performance and spatial transferability supports the use of simpler models when extrapolating habitat suitability maps to different areas. Differences in the form and performance of models from different areas may supply further information on the processes shaping species' distributions. Spatial transferability of habitat models can be used to support fishery management when the information is scarce but caution needs to be applied when making inference and a multi-area transferability analysis is preferable to bilateral comparisons between areas.

Quantum Engineering of Dynamical Gauge Fields on Optical Lattices

DTIC Science & Technology

2016-07-08

exact blocking formulas from the TRG formulation of the transfer matrix. The second is a worm algorithm. The particle number distributions obtained...a fact that can be explained by an approximate particle- hole symmetry. We have also developed a computer code suite for simulating the Abelian

In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood

EPA Science Inventory

Micronized copper azole (MCA) and micronized copper quaternary are the latest wood preservatives to replace the liquid lkaline copper and chromated copper arsenate preservatives due to concerns over the toxicity or lack of effectiveness of the earlier formulations. Today, the use...

[How to carry out work on family planning after adopting production responsibility systems in rural areas].

PubMed

Xiao, S H

1982-05-29

After the Third Meeting of the Eleventh People's Congress, the entire responsibility for agricultural production was transferred to a lower level. Peasants in various areas have adopted the so called production responsibility system, and the phenomenon of an increased population rate has also appeared in some areas. In this article, the author discusses how to solve these problems created by the new situation. The 1st step is try to control population growth through socialist propaganda education, administrative measures, economic incentives and punishments, and family planning work. The 2nd step is to popularize the practice of having only 1 child per household in the rural areas. The 2nd and 3rd child in each family should be controlled and prohibited. This policy formulated by the Central Government should be carried out thoroughly. Families which follow the policy and have only 1 child should be encouraged with economic rewards, and those families which have 2 or more children should be punished economically. The 3rd step is to establish a national work team to be in charge of family planning and birth control. There should be an ideological unity among the nation's leadership. Party members and cadres should establish themselves as good examples for the people so that the population control work may become successful.

33 CFR 127.319 - LNG transfer.

Code of Federal Regulations, 2010 CFR

2010-07-01

... that— (1) The marine transfer area for LNG is under the supervision of a person in charge, who has no other assigned duties during the transfer operation; (2) Personnel transferring fuel or oily waste are... discontinued— (i) Before electrical storms or uncontrolled fires are adjacent to the marine transfer area for...

33 CFR 127.319 - LNG transfer.

Code of Federal Regulations, 2011 CFR

2011-07-01

... that— (1) The marine transfer area for LNG is under the supervision of a person in charge, who has no other assigned duties during the transfer operation; (2) Personnel transferring fuel or oily waste are... discontinued— (i) Before electrical storms or uncontrolled fires are adjacent to the marine transfer area for...

A scattering model for forested area

NASA Technical Reports Server (NTRS)

Karam, M. A.; Fung, A. K.

1988-01-01

A forested area is modeled as a volume of randomly oriented and distributed disc-shaped, or needle-shaped leaves shading a distribution of branches modeled as randomly oriented finite-length, dielectric cylinders above an irregular soil surface. Since the radii of branches have a wide range of sizes, the model only requires the length of a branch to be large compared with its radius which may be any size relative to the incident wavelength. In addition, the model also assumes the thickness of a disc-shaped leaf or the radius of a needle-shaped leaf is much smaller than the electromagnetic wavelength. The scattering phase matrices for disc, needle, and cylinder are developed in terms of the scattering amplitudes of the corresponding fields which are computed by the forward scattering theorem. These quantities along with the Kirchoff scattering model for a randomly rough surface are used in the standard radiative transfer formulation to compute the backscattering coefficient. Numerical illustrations for the backscattering coefficient are given as a function of the shading factor, incidence angle, leaf orientation distribution, branch orientation distribution, and the number density of leaves. Also illustrated are the properties of the extinction coefficient as a function of leaf and branch orientation distributions. Comparisons are made with measured backscattering coefficients from forested areas reported in the literature.

Applied Routh approximation

NASA Technical Reports Server (NTRS)

Merrill, W. C.

1978-01-01

The Routh approximation technique for reducing the complexity of system models was applied in the frequency domain to a 16th order, state variable model of the F100 engine and to a 43d order, transfer function model of a launch vehicle boost pump pressure regulator. The results motivate extending the frequency domain formulation of the Routh method to the time domain in order to handle the state variable formulation directly. The time domain formulation was derived and a characterization that specifies all possible Routh similarity transformations was given. The characterization was computed by solving two eigenvalue-eigenvector problems. The application of the time domain Routh technique to the state variable engine model is described, and some results are given. Additional computational problems are discussed, including an optimization procedure that can improve the approximation accuracy by taking advantage of the transformation characterization.

An implicit-iterative solution of the heat conduction equation with a radiation boundary condition

NASA Technical Reports Server (NTRS)

Williams, S. D.; Curry, D. M.

1977-01-01

For the problem of predicting one-dimensional heat transfer between conducting and radiating mediums by an implicit finite difference method, four different formulations were used to approximate the surface radiation boundary condition while retaining an implicit formulation for the interior temperature nodes. These formulations are an explicit boundary condition, a linearized boundary condition, an iterative boundary condition, and a semi-iterative boundary method. The results of these methods in predicting surface temperature on the space shuttle orbiter thermal protection system model under a variety of heating rates were compared. The iterative technique caused the surface temperature to be bounded at each step. While the linearized and explicit methods were generally more efficient, the iterative and semi-iterative techniques provided a realistic surface temperature response without requiring step size control techniques.

The use of asymmetrical flow field-flow fractionation with on-line detection in the study of drug retention within liposomal nanocarriers and drug transfer kinetics.

PubMed

Hinna, Askell Hvid; Hupfeld, Stefan; Kuntsche, Judith; Brandl, Martin

2016-05-30

Due to their solubilizing capabilities, liposomes (phospholipid vesicles) are suited for designing formulations for intravenous administration of drug compounds which are poorly water-soluble. Despite the good in-vitro stability of such formulations with minimal drug leakage, upon i.v. injection there is a risk of premature drug loss due to drug transfer to plasma proteins and cell membranes. Here we report on the refinement of a recently introduced simple in vitro predictive tool by Hinna and colleagues in 2014, which brings small drug loaded (donor) liposomes in contact with large acceptor liposomes, the latter serving as a model mimicking biological sinks in the body. The donor- and acceptor-liposomes were subsequently separated using asymmetrical flow field-flow fractionation (AF4), during which the sample is exposed to a large volume of eluent which corresponds to a dilution factor of approximately 600. The model drug content in the donor- and acceptor fraction was quantified by on-line UV/VIS extinction measurements with correction for turbidity and by off-line HPLC measurements of collected fractions. The refined method allowed for (near) baseline separation of donor and acceptor vesicles as well as reliable quantification of the drug content not only of the donor- but now also of the acceptor-liposomes due to their improved size-homogeneity, colloidal stability and reduced turbidity. This improvement over the previously reported approach allowed for simultaneous quantification of both drug transfer and drug release to the aqueous phase. By sampling at specific incubation times, the release and transfer kinetics of the model compound p-THPP (5,10,15,20-tetrakis(4-hydroxyphenyl)21H,23H-porphine) was determined. p-THPP is structurally closely related to the photosensitizer temoporfin, which is in clinical use and under evaluation in liposomal formulations. The transfer of p-THPP to the acceptor vesicles followed 1st order kinetics with a half-life of approximately 300 min. As expected, equilibrium distribution between donor- and acceptor vesicles was proportional to the lipid mass ratio. An initial rapid transfer of p-THPP was found (∼ 5%) and investigated further by determining the extent of transfer between donor and acceptor during separation. The donor- and acceptor phase were found to be separated within few minutes and only minor (≤ 2%) transfer could be detected within the AF4 channel under the conditions applied for fractionation. These results demonstrates the potential of our AF4 based method as an in vitro tool to determine retention properties of lipophilic compounds within liposomal carriers in particular, but also within a variety of nano-particulate carriers provided that they exhibit a sufficient size difference compared to the applied colloidal acceptor phase. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluating the transport layer of the ALFA framework for the Intel® Xeon Phi™ Coprocessor

NASA Astrophysics Data System (ADS)

Santogidis, Aram; Hirstius, Andreas; Lalis, Spyros

2015-12-01

The ALFA framework supports the software development of major High Energy Physics experiments. As part of our research effort to optimize the transport layer of ALFA, we focus on profiling its data transfer performance for inter-node communication on the Intel Xeon Phi Coprocessor. In this article we present the collected performance measurements with the related analysis of the results. The optimization opportunities that are discovered, help us to formulate the future plans of enabling high performance data transfer for ALFA on the Intel Xeon Phi architecture.

Radiative interactions in transient energy transfer in gaseous systems

NASA Technical Reports Server (NTRS)

Tiwari, S. N.

1985-01-01

Analyses and numerical procedures are presented to investigate the radiative interactions in transient energy transfer processes in gaseous systems. The nongray radiative formulations are based on the wide-band model correlations for molecular absorption. Various relations for the radiative flux are developed; these are useful for different flow conditions and physical problems. Specific plans for obtaining extensive results for different cases are presented. The methods presented in this study can be extended easily to investigate the radiative interactions in realistic flows of hydrogen-air species in the scramjet engine.

Modeling of high pressure arc-discharge with a fully-implicit Navier-Stokes stabilized finite element flow solver

NASA Astrophysics Data System (ADS)

Sahai, A.; Mansour, N. N.; Lopez, B.; Panesi, M.

2017-05-01

This work addresses the modeling of high pressure electric discharge in an arc-heated wind tunnel. The combined numerical solution of Poisson’s equation, radiative transfer equations, and the set of Favre-averaged thermochemical nonequilibrium Navier-Stokes equations allows for the determination of the electric, radiation, and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles with the Chapman-Enskog method. A multi-temperature formulation is used to account for thermal non-equilibrium. Finally, the turbulence closure of the flow equations is obtained by means of the Spalart-Allmaras model, which requires the solution of an additional scalar transport equation. A Streamline upwind Petrov-Galerkin stabilized finite element formulation is employed to solve the Navier-Stokes equation. The electric field equation is solved using the standard Galerkin formulation. A stable formulation for the radiative transfer equations is obtained using the least-squares finite element method. The developed simulation framework has been applied to investigate turbulent plasma flows in the 20 MW Aerodynamic Heating Facility at NASA Ames Research Center. The current model is able to predict the process of energy addition and re-distribution due to Joule heating and thermal radiation, resulting in a hot central core surrounded by colder flow. The use of an unsteady three-dimensional treatment also allows the asymmetry due to a dynamic electric arc attachment point in the cathode chamber to be captured accurately. The current work paves the way for detailed estimation of operating characteristics for arc-heated wind tunnels which are critical in testing thermal protection systems.

Protease Inhibition by Oleic Acid Transfer From Chronic Wound Dressings to Albumin

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

Edwards, J. V.; Howley, Phyllis; Davis, Rachel M.

High elastase and cathepsin G activities have been observed in chronic wounds. These levels can inhibit healing through degradation of growth factors, cytokines, and extracellular matrix proteins. Oleic acid (18:1) is a non-toxic elastase inhibitor with some potential for redressing the imbalance of elastase activity found in chronic wounds. Cotton wound dressing material was characterized as a transfer carrier for affinity uptake of 18:1 by albumin under conditions mimicking chronic wounds. 18:1-treated cotton was examined for its ability to bind and release the fatty acid in the presence of albumin. The mechanism of 18:1 uptake from cotton and binding bymore » albumin was examined with both intact dressings and cotton fiber-designed chromatography. Raman spectra of the albumin-18:1 complexes under liquid-liquid equilibrium conditions revealed fully saturated albumin-18:1 complexes with a 1:1 weight ratio of albumin:18:1. Cotton chromatography under liquid-solid equilibrium conditions revealed oleic acid transfer from cotton to albumin at 27 mole equivalents of 18:1 per mole albumin. Cotton was contrasted with hydrogel, and hydrocolloid wound dressing for its comparative ability to lower elastase activity. Each dressing material evaluated was found to release 18:1 in the presence of albumin with significant inhibition of elastase activity. The 18:1-formulated wound dressings lowered elastase activity in a dose dependent manner in the order cotton gauze > hydrogel > hydrocolloid. In contrast the cationic serine protease Cathepsin G was inihibited by 18:1 within a narrow range of 18:1-cotton formulations. Four per cent Albumin solutions were most effective in binding cotton bound-18:1. However, 2% albumin was sufficient to transfer quantities of 18:1 necessary to achieve a significant elastase-lowering effect. Formulations with 128 mg 18:1/g cotton gauze had equivalent elastase lowering with 1 - 4% albumin. 18:1 bound to cotton wound dressings may have promise in the selective lowering of cationic serine protease activity useful in topical application for chronic inflammatory pathogenesis.« less

21 CFR 109.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

Code of Federal Regulations, 2011 CFR

2011-04-01

... (Japan). PCB's are highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's include, or did include in the past, their use as electrical transformer and capacitor fluids, heat transfer fluids, hydraulic fluids, and plasticizers, and in formulations of lubricants, coatings, and inks...

21 CFR 509.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

Code of Federal Regulations, 2011 CFR

2011-04-01

... (Japan). PCB's are highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's include, or did include in the past, their use as electrical transformer and capacitor fluids, heat transfer fluids, hydraulic fluids, and plasticizers, and in formulations of lubricants, coatings, and inks...

2013 MOLECULAR ENERGY TRANSFER GORDON RESEARCH CONFERENCE (JANUARY 13-18, 2013 - VENTURA BEACH MARRIOTT, VENTURA CA

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

Reid, Scott A.

2012-10-18

Sessions covered all areas of molecular energy transfer, with 10 sessions of talks and poster sessions covering the areas of :  Energy Transfer in Inelastic and Reactive Scattering  Energy Transfer in Photoinitiated and Unimolecular Reactions  Non-adiabatic Effects in Energy Transfer  Energy Transfer at Surfaces and Interfaces  Energy Transfer in Clusters, Droplets, and Aerosols  Energy Transfer in Solution and Solid  Energy Transfer in Complex Systems  Energy Transfer: New vistas and horizons  Molecular Energy Transfer: Where Have We Been and Where are We Going?

Calculation of the angular radiance distribution for a coupled atmosphere and canopy

NASA Technical Reports Server (NTRS)

Liang, Shunlin; Strahler, Alan H.

1993-01-01

The radiative transfer equations for a coupled atmosphere and canopy are solved numerically by an improved Gauss-Seidel iteration algorithm. The radiation field is decomposed into three components: unscattered sunlight, single scattering, and multiple scattering radiance for which the corresponding equations and boundary conditions are set up and their analytical or iterational solutions are explicitly derived. The classic Gauss-Seidel algorithm has been widely applied in atmospheric research. This is its first application for calculating the multiple scattering radiance of a coupled atmosphere and canopy. This algorithm enables us to obtain the internal radiation field as well as radiances at boundaries. Any form of bidirectional reflectance distribution function (BRDF) as a boundary condition can be easily incorporated into the iteration procedure. The hotspot effect of the canopy is accommodated by means of the modification of the extinction coefficients of upward single scattering radiation and unscattered sunlight using the formulation of Nilson and Kuusk. To reduce the computation for the case of large optical thickness, an improved iteration formula is derived to speed convergence. The upwelling radiances have been evaluated for different atmospheric conditions, leaf area index (LAI), leaf angle distribution (LAD), leaf size and so on. The formulation presented in this paper is also well suited to analyze the relative magnitude of multiple scattering radiance and single scattering radiance in both the visible and near infrared regions.

Application of solution calorimetry in pharmaceutical and biopharmaceutical research.

PubMed

Royall, P G; Gaisford, S

2005-06-01

In solution calorimetry the heat of solution (Delta(sol)H) is recorded as a solute (usually a solid) dissolves in an excess of solvent. Such measurements are valuable during all the phases of pharmaceutical formulation and the number of applications of the technique is growing. For instance, solution calorimetry is extremely useful during preformulation for the detection and quantification of polymorphs, degrees of crystallinity and percent amorphous content; knowledge of all of these parameters is essential in order to exert control over the manufacture and subsequent performance of a solid pharmaceutical. Careful experimental design and data interpretation also allows the measurement of the enthalpy of transfer (Delta(trans)H) of a solute between two phases. Because solution calorimetry does not require optically transparent solutions, and can be used to study cloudy or turbid solutions or suspensions directly, measurement of Delta(trans)H affords the opportunity to study the partitioning of drugs into, and across, biological membranes. It also allows the in-situ study of cellular systems. Furthermore, novel experimental methodologies have led to the increasing use of solution calorimetry to study a wider range of phenomena, such as the precipitation of drugs from supersaturated solutions or the formation of liposomes from phospholipid films. It is the purpose of this review to discuss some of these applications, in the context of pharmaceutical formulation and preformulation, and highlight some of the potential future areas where solution calorimetry might find applications.

Highly Enhanced Electromechanical Stability of Large-Area Graphene with Increased Interfacial Adhesion Energy by Electrothermal-Direct Transfer for Transparent Electrodes.

PubMed

Kim, Jangheon; Kim, Gi Gyu; Kim, Soohyun; Jung, Wonsuk

2016-09-07

Graphene, a two-dimensional sheet of carbon atoms in a hexagonal lattice structure, has been extensively investigated for research and industrial applications as a promising material with outstanding electrical, mechanical, and chemical properties. To fabricate graphene-based devices, graphene transfer to the target substrate with a clean and minimally defective surface is the first step. However, graphene transfer technologies require improvement in terms of uniform transfer with a clean, nonfolded and nontorn area, amount of defects, and electromechanical reliability of the transferred graphene. More specifically, uniform transfer of a large area is a key challenge when graphene is repetitively transferred onto pretransferred layers because the adhesion energy between graphene layers is too low to ensure uniform transfer, although uniform multilayers of graphene have exhibited enhanced electrical and optical properties. In this work, we developed a newly suggested electrothermal-direct (ETD) transfer method for large-area high quality monolayer graphene with less defects and an absence of folding or tearing of the area at the surface. This method delivers uniform multilayer transfer of graphene by repetitive monolayer transfer steps based on high adhesion energy between graphene layers and the target substrate. To investigate the highly enhanced electromechanical stability, we conducted mechanical elastic bending experiments and reliability tests in a highly humid environment. This ETD-transferred graphene is expected to replace commercial transparent electrodes with ETD graphene-based transparent electrodes and devices such as a touch panels with outstanding electromechanical stability.

Preparation and evaluation of a multimodal minoxidil microemulsion versus minoxidil alone in the treatment of androgenic alopecia of mixed etiology: a pilot study.

PubMed

Sakr, Farouk M; Gado, Ali Mi; Mohammed, Haseebur R; Adam, Abdel Nasser Ismail

2013-01-01

The variable success of topical minoxidil in the treatment of androgenic alopecia has led to the hypothesis that other pathways could mediate this form of hair loss, including infection and/or microinflammation of the hair follicles. In this study, we prepared a multimodal microemulsion comprising minoxidil (a dihydrotestosterone antagonist), diclofenac (a nonsteroidal anti-inflammatory agent), and tea tree oil (an anti-infective agent). We investigated the stability and physicochemical properties of this formulation, and its therapeutic efficacy compared with a formulation containing minoxidil alone in the treatment of androgenic alopecia. We developed a multimodal oil/water (o/w) microemulsion, a formulation containing minoxidil alone, and another containing vehicle. A three-phase diagram was constructed to obtain the optimal concentrations of the selected oil, surfactant, and cosurfactant. Thirty-two men aged 18-30 years were randomized to apply 1 mL of microemulsion containing the multimodal formulation (formulation A, n = 11), minoxidil alone (formulation B, n = 11) or placebo (formulation C, n = 10) twice daily to the affected area for 32 weeks. Efficacy was evaluated by mean hair count, thickness, and weight on the targeted area of the scalp. Global photographs were taken, changes in the area of scalp coverage were assessed by patients and external investigators, and the benefits and safety of the study medications were evaluated. The physical stability of formula A was examined after a shelf storage period of 24 months. Formulation A achieved a significantly superior response than formulations B and C in terms of mean hair count (P < 0.001), mean hair weight (P < 0.001), and mean hair thickness (P < 0.05). A patient self-assessment questionnaire demonstrated that the multimodal minoxidil formulation significantly (P < 0.001) slowed hair loss, increased hair growth, and improved appearance, and showed no appreciable side effects, such as itching and/or inflammation of the scalp compared with the minoxidil alone and placebo formulations. These improvements were in agreement with the photographic assessments made by the investigators. Formula A was shown to be an o/w formulation with consistent pH, viscosity, specific gravity, and homogeneity, and was physically stable after 24 months of normal storage. A multimodal microemulsion comprising minoxidil, diclofenac, and tea tree oil was significantly superior to minoxidil alone and placebo in terms of stability, safety, and efficacy, and achieved an earlier response in the treatment of androgenic alopecia compared with minoxidil alone in this 32-week pilot study.

Preparation and evaluation of a multimodal minoxidil microemulsion versus minoxidil alone in the treatment of androgenic alopecia of mixed etiology: a pilot study

PubMed Central

Sakr, Farouk M; Gado, Ali MI; Mohammed, Haseebur R; Adam, Abdel Nasser Ismail

2013-01-01

Background: The variable success of topical minoxidil in the treatment of androgenic alopecia has led to the hypothesis that other pathways could mediate this form of hair loss, including infection and/or microinflammation of the hair follicles. In this study, we prepared a multimodal microemulsion comprising minoxidil (a dihydrotestosterone antagonist), diclofenac (a nonsteroidal anti-inflammatory agent), and tea tree oil (an anti-infective agent). We investigated the stability and physicochemical properties of this formulation, and its therapeutic efficacy compared with a formulation containing minoxidil alone in the treatment of androgenic alopecia. Methods: We developed a multimodal oil/water (o/w) microemulsion, a formulation containing minoxidil alone, and another containing vehicle. A three-phase diagram was constructed to obtain the optimal concentrations of the selected oil, surfactant, and cosurfactant. Thirty-two men aged 18–30 years were randomized to apply 1 mL of microemulsion containing the multimodal formulation (formulation A, n = 11), minoxidil alone (formulation B, n = 11) or placebo (formulation C, n = 10) twice daily to the affected area for 32 weeks. Efficacy was evaluated by mean hair count, thickness, and weight on the targeted area of the scalp. Global photographs were taken, changes in the area of scalp coverage were assessed by patients and external investigators, and the benefits and safety of the study medications were evaluated. The physical stability of formula A was examined after a shelf storage period of 24 months. Results: Formulation A achieved a significantly superior response than formulations B and C in terms of mean hair count (P < 0.001), mean hair weight (P < 0.001), and mean hair thickness (P < 0.05). A patient self-assessment questionnaire demonstrated that the multimodal minoxidil formulation significantly (P < 0.001) slowed hair loss, increased hair growth, and improved appearance, and showed no appreciable side effects, such as itching and/or inflammation of the scalp compared with the minoxidil alone and placebo formulations. These improvements were in agreement with the photographic assessments made by the investigators. Formula A was shown to be an o/w formulation with consistent pH, viscosity, specific gravity, and homogeneity, and was physically stable after 24 months of normal storage. Conclusion: A multimodal microemulsion comprising minoxidil, diclofenac, and tea tree oil was significantly superior to minoxidil alone and placebo in terms of stability, safety, and efficacy, and achieved an earlier response in the treatment of androgenic alopecia compared with minoxidil alone in this 32-week pilot study. PMID:23807837

Modelling charge transfer reactions with the frozen density embedding formalism

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

Pavanello, Michele; Neugebauer, Johannes

2011-12-21

The frozen density embedding (FDE) subsystem formulation of density-functional theory is a useful tool for studying charge transfer reactions. In this work charge-localized, diabatic states are generated directly with FDE and used to calculate electronic couplings of hole transfer reactions in two {pi}-stacked nucleobase dimers of B-DNA: 5{sup '}-GG-3{sup '} and 5{sup '}-GT-3{sup '}. The calculations rely on two assumptions: the two-state model, and a small differential overlap between donor and acceptor subsystem densities. The resulting electronic couplings agree well with benchmark values for those exchange-correlation functionals that contain a high percentage of exact exchange. Instead, when semilocal GGA functionalsmore » are used the electronic couplings are grossly overestimated.« less

Discrete Data Transfer Technique for Fluid-Structure Interaction

NASA Technical Reports Server (NTRS)

Samareh, Jamshid A.

2007-01-01

This paper presents a general three-dimensional algorithm for data transfer between dissimilar meshes. The algorithm is suitable for applications of fluid-structure interaction and other high-fidelity multidisciplinary analysis and optimization. Because the algorithm is independent of the mesh topology, we can treat structured and unstructured meshes in the same manner. The algorithm is fast and accurate for transfer of scalar or vector fields between dissimilar surface meshes. The algorithm is also applicable for the integration of a scalar field (e.g., coefficients of pressure) on one mesh and injection of the resulting vectors (e.g., force vectors) onto another mesh. The author has implemented the algorithm in a C++ computer code. This paper contains a complete formulation of the algorithm with a few selected results.

Analysis of Aerospike Plume Induced Base-Heating Environment

NASA Technical Reports Server (NTRS)

Wang, Ten-See

1998-01-01

Computational analysis is conducted to study the effect of an aerospike engine plume on X-33 base-heating environment during ascent flight. To properly account for the effect of forebody and aftbody flowfield such as shocks and to allow for potential plume-induced flow-separation, thermo-flowfield of trajectory points is computed. The computational methodology is based on a three-dimensional finite-difference, viscous flow, chemically reacting, pressure-base computational fluid dynamics formulation, and a three-dimensional, finite-volume, spectral-line based weighted-sum-of-gray-gases radiation absorption model computational heat transfer formulation. The predicted convective and radiative base-heat fluxes are presented.

A mortar formulation including viscoelastic layers for vibration analysis

NASA Astrophysics Data System (ADS)

Paolini, Alexander; Kollmannsberger, Stefan; Rank, Ernst; Horger, Thomas; Wohlmuth, Barbara

2018-05-01

In order to reduce the transfer of sound and vibrations in structures such as timber buildings, thin elastomer layers can be embedded between their components. The influence of these elastomers on the response of the structures in the low frequency range can be determined accurately by using conforming hexahedral finite elements. Three-dimensional mesh generation, however, is yet a non-trivial task and mesh refinements which may be necessary at the junctions can cause a high computational effort. One remedy is to mesh the components independently from each other and to couple them using the mortar method. Further, the hexahedral mesh for the thin elastomer layer itself can be avoided by integrating its elastic behavior into the mortar formulation. The present paper extends this mortar formulation to take damping into account such that frequency response analyses can be performed more accurately. Finally, the proposed method is verified by numerical examples.

Fully unsteady subsonic and supersonic potential aerodynamics for complex aircraft configurations with applications to flutter

NASA Technical Reports Server (NTRS)

Tseng, K.; Morino, L.

1975-01-01

A general formulation is presented for the analysis of steady and unsteady, subsonic and supersonic aerodynamics for complex aircraft configurations. The theoretical formulation, the numerical procedure, the description of the program SOUSSA (steady, oscillatory and unsteady, subsonic and supersonic aerodynamics) and numerical results are included. In particular, generalized forces for fully unsteady (complex frequency) aerodynamics for a wing-body configuration, AGARD wing-tail interference in both subsonic and supersonic flows as well as flutter analysis results are included. The theoretical formulation is based upon an integral equation, which includes completely arbitrary motion. Steady and oscillatory aerodynamic flows are considered. Here small-amplitude, fully transient response in the time domain is considered. This yields the aerodynamic transfer function (Laplace transform of the fully unsteady operator) for frequency domain analysis. This is particularly convenient for the linear systems analysis of the whole aircraft.

Heat transfer model and finite element formulation for simulation of selective laser melting

NASA Astrophysics Data System (ADS)

Roy, Souvik; Juha, Mario; Shephard, Mark S.; Maniatty, Antoinette M.

2017-10-01

A novel approach and finite element formulation for modeling the melting, consolidation, and re-solidification process that occurs in selective laser melting additive manufacturing is presented. Two state variables are introduced to track the phase (melt/solid) and the degree of consolidation (powder/fully dense). The effect of the consolidation on the absorption of the laser energy into the material as it transforms from a porous powder to a dense melt is considered. A Lagrangian finite element formulation, which solves the governing equations on the unconsolidated reference configuration is derived, which naturally considers the effect of the changing geometry as the powder melts without needing to update the simulation domain. The finite element model is implemented into a general-purpose parallel finite element solver. Results are presented comparing to experimental results in the literature for a single laser track with good agreement. Predictions for a spiral laser pattern are also shown.

Localized treatments using commercial dust and liquid formulations of fipronil against Coptotermes formosanus (Isoptera: Rhinotermitidae) in the laboratory.

PubMed

Gautam, Bal K; Henderson, Gregg; Wang, Cai

2014-04-01

Use of proper application methods and formulations of termiticides are important to reduce their negative impact to the environment. In this study, we conducted laboratory experiments to determine the effect of localized treatments with commercial dust and liquid formulations of fipronil against Formosan subterranean termites, Coptotermes formosanus Shiraki. The test arena consisted of a specially designed 16-chambered structure with a center chamber connected to 5 foraging chambers that themselves were connected to 10 additional foraging chambers. One peripheral chamber received a liquid or dust treatment and termites were released in the center chamber. Results showed that >91% of the termites were dead within the 9-d test period despite the localized treatment of only 1 foraging chamber. Termites that were still alive after 9 d were transferred to an untreated dish and held for 10 more days. The majority of those termites were dead and the rest were moribund on day 19. Regardless of the specific dish treated, both formulations of fipronil were found to be highly efficacious. Termites did not exhibit repellency to either formulation. Our results suggest that localized (or spot) treatment with either commercially available dust or liquid formulations of fipronil can be a viable option for control of a termite infestation where complete soil drenching is not desirable. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Exciton-exciton annihilation in a disordered molecular system by direct and multistep Förster transfer

NASA Astrophysics Data System (ADS)

Fennel, Franziska; Lochbrunner, Stefan

2015-10-01

Exciton annihilation dynamics in a disordered organic model system is investigated by ultrafast absorption spectroscopy. We show that the temporal evolution of the exciton density can be quantitatively understood by applying Förster energy transfer theory to describe the diffusion of the excitons as well as the annihilation step itself. To this end, previous formulations of Förster theory are extended to account for the inhomogeneous distribution of the S0-S1 transition energies resulting in an effective exciton diffusion constant. Two annihilation pathways are considered, the direct transfer of an exciton between two excited molecules and diffusive motion by multiple transfer steps towards a second exciton preceding the annihilation event. One pathway can be emphasized with respect to the other by tuning the exciton diffusion constant via the chromophore concentration. The investigated system allows one to extract all relevant parameters for the description and provides in this way a proof that the annihilation dynamics can be entirely understood and modeled by Förster energy transfer.

Time-free transfers between libration-point orbits in the elliptic restricted problem

NASA Astrophysics Data System (ADS)

Howell, K. C.; Hiday-Johnston, L. A.

This work is part of a larger research effort directed toward the formulation of a strategy to design optimal time-free impulsive transfers between three-dimensional libration-point orbits in the vicinity of the interior LI libration point of the Sun-Earth/Moon barycenter system. Inferior transfers that move a spacecraft from a large halo orbit to a smaller halo orbit are considered here. Primer vector theory is applied to non-optimal impulsive trajectories in the elliptic restricted three-body problem in order to establish whether the implementation of a coast in the initial orbit, a coast in the final orbit, or dual coasts accomplishes a reduction in fuel expenditure. The addition of interior impulses is also considered. Results indicate that a substantial savings in fuel can be achieved by the allowance for coastal periods on the specified libration-point orbits. The resulting time-free inferior transfers are compared to time-free superior transfers between halo orbits of equal z-amplitude separation.

Time-free transfers between libration-point orbits in the elliptic restricted problem

NASA Astrophysics Data System (ADS)

Howell, K. C.; Hiday, L. A.

1992-08-01

This work is directed toward the formulation of a strategy to design optimal time-free impulsive transfers between 3D libration-point orbits in the vicinity of the interior L1 libration point of the sun-earth/moon barycenter system. Inferior transfers that move a spacecraft from a large halo orbit to a smaller halo orbit are considered here. Primer vector theory is applied to nonoptimal impulsive trajectories in the elliptic restricted three-body problem in order to establish whether the implementation of a coast in the initial orbit, a coast in the final orbit, or dual coasts accomplishes a reduction in fuel expenditure. The addition of interior impulses is also considered. Results indicate that a substantial savings in fuel can be achieved by the allowance for coastal periods on the specified libration-point orbits. The resulting time-free inferior transfers are compared to time-free superior transfers between halo orbits of equal z-amplitude separation.

Tuning the driving force for exciton dissociation in single-walled carbon nanotube heterojunctions

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

Ihly, Rachelle; Mistry, Kevin S.; Ferguson, Andrew J.

2016-04-25

Understanding the kinetics and energetics of interfacial electron transfer in molecular systems is crucial for the development of a broad array of technologies, including photovoltaics, solar fuel systems and energy storage. The Marcus formulation for electron transfer relates the thermodynamic driving force and reorganization energy for charge transfer between a given donor/acceptor pair to the kinetics and yield of electron transfer. Here we investigated the influence of the thermodynamic driving force for photoinduced electron transfer (PET) between single-walled carbon nanotubes (SWCNTs) and fullerene derivatives by employing time-resolved microwave conductivity as a sensitive probe of interfacial exciton dissociation. For the firstmore » time, we observed the Marcus inverted region (in which driving force exceeds reorganization energy) and quantified the reorganization energy for PET for a model SWCNT/acceptor system. The small reorganization energies (about 130 meV, most of which probably arises from the fullerene acceptors) are beneficial in minimizing energy loss in photoconversion schemes.« less

A Variational Formalism for the Radiative Transfer Equation and a Geostrophic, Hydrostatic Atmosphere: Prelude to Model 3

NASA Technical Reports Server (NTRS)

Achtemeier, Gary L.

1991-01-01

The second step in development of MODEL III is summarized. It combines the four radiative transfer equations of the first step with the equations for a geostrophic and hydrostatic atmosphere. This step is intended to bring radiance into a three dimensional balance with wind, height, and temperature. The use of the geostrophic approximation in place of the full set of primitive equations allows for an easier evaluation of how the inclusion of the radiative transfer equation increases the complexity of the variational equations. Seven different variational formulations were developed for geostrophic, hydrostatic, and radiative transfer equations. The first derivation was too complex to yield solutions that were physically meaningful. For the remaining six derivations, the variational method gave the same physical interpretation (the observed brightness temperatures could provide no meaningful input to a geostrophic, hydrostatic balance) at least through the problem solving methodology used in these studies. The variational method is presented and the Euler-Lagrange equations rederived for the geostrophic, hydrostatic, and radiative transfer equations.

Heat Transfer and Geometrical Analysis of Thermoelectric Converters Driven by Concentrated Solar Radiation

PubMed Central

Suter, Clemens; Tomeš, Petr; Weidenkaff, Anke; Steinfeld, Aldo

2010-01-01

A heat transfer model that couples radiation/conduction/convection heat transfer with electrical potential distribution is developed for a thermoelectric converter (TEC) subjected to concentrated solar radiation. The 4-leg TEC module consists of two pairs of p-type La1.98Sr0.02CuO4 and n-type CaMn0.98Nb0.02O3 legs that are sandwiched between two ceramic Al2O3 hot/cold plates and connected electrically in series and thermally in parallel. The governing equations for heat transfer and electrical potential are formulated, discretized and solved numerically by applying the finite volume (FV) method. The model is validated in terms of experimentally measured temperatures and voltages/power using a set of TEC demonstrator modules, subjected to a peak radiative flux intensity of 300 suns. The heat transfer model is then applied to examine the effect of the geometrical parameters (e.g. length/width of legs) on the solar-to-electricity energy conversion efficiency.

Multiple burn fuel-optimal orbit transfers: Numerical trajectory computation and neighboring optimal feedback guidance

NASA Technical Reports Server (NTRS)

Chuang, C.-H.; Goodson, Troy D.; Ledsinger, Laura A.

1995-01-01

This report describes current work in the numerical computation of multiple burn, fuel-optimal orbit transfers and presents an analysis of the second variation for extremal multiple burn orbital transfers as well as a discussion of a guidance scheme which may be implemented for such transfers. The discussion of numerical computation focuses on the use of multivariate interpolation to aid the computation in the numerical optimization. The second variation analysis includes the development of the conditions for the examination of both fixed and free final time transfers. Evaluations for fixed final time are presented for extremal one, two, and three burn solutions of the first variation. The free final time problem is considered for an extremal two burn solution. In addition, corresponding changes of the second variation formulation over thrust arcs and coast arcs are included. The guidance scheme discussed is an implicit scheme which implements a neighboring optimal feedback guidance strategy to calculate both thrust direction and thrust on-off times.

33 CFR 156.120 - Requirements for transfer.

Code of Federal Regulations, 2010 CFR

2010-07-01

... prevent kinking or other damage to the hose and strain on its coupling. (d) Each part of the transfer.... (cc) Smoking is not permitted in the facilities marine transfer area except in designated smoking areas. (dd) Welding, hot work operations and smoking are prohibited on vessels during the transfer of...

Application of linear multifrequency-grey acceleration to preconditioned Krylov iterations for thermal radiation transport

DOE PAGES

Till, Andrew T.; Warsa, James S.; Morel, Jim E.

2018-06-15

The thermal radiative transfer (TRT) equations comprise a radiation equation coupled to the material internal energy equation. Linearization of these equations produces effective, thermally-redistributed scattering through absorption-reemission. In this paper, we investigate the effectiveness and efficiency of Linear-Multi-Frequency-Grey (LMFG) acceleration that has been reformulated for use as a preconditioner to Krylov iterative solution methods. We introduce two general frameworks, the scalar flux formulation (SFF) and the absorption rate formulation (ARF), and investigate their iterative properties in the absence and presence of true scattering. SFF has a group-dependent state size but may be formulated without inner iterations in the presence ofmore » scattering, while ARF has a group-independent state size but requires inner iterations when scattering is present. We compare and evaluate the computational cost and efficiency of LMFG applied to these two formulations using a direct solver for the preconditioners. Finally, this work is novel because the use of LMFG for the radiation transport equation, in conjunction with Krylov methods, involves special considerations not required for radiation diffusion.« less

Heat Transfer to Longitudinal Laminar Flow Between Cylinders

NASA Technical Reports Server (NTRS)

Sparrow, Ephraim M.; Loeffler, Albert L. Jr.; Hubbard, H. A.

1960-01-01

Consideration is given to the fully developed heat transfer characteristics for longitudinal laminar flow between cylinders arranged in an equilateral triangular array. The analysis is carried out for the condition of uniform heat transfer per unit length. Solutions are obtained for the temperature distribution, and from these, Nusselt numbers are derived for a wide range of spacing-to-diameter ratios. It is found that as the spacing ratio increases, so also does the wall-to-bulk temperature difference for a fixed heat transfer per unit length. Corresponding to a uniform surface temperature around the circumference of a cylinder, the circumferential variation of the local heat flux is computed. For spacing ratios of 1.5 - 2.0 and greater, uniform peripheral wall temperature and uniform peripheral heat flux are simultaneously achieved. A simplified analysis which neglects circumferential variations is also carried out, and the results are compared with those from the more exact formulation.

Physical principle of airway design in human lungs

NASA Astrophysics Data System (ADS)

Park, Keunhwan; Son, Taeho; Kim, Wonjung; Kim, Ho-Young

2014-11-01

From an engineering perspective, lungs are natural microfluidic devices that extract oxygen from air. In the bronchial tree, airways branch by dichotomy with a systematic reduction of their diameters. It is generally accepted that in conducting airways, which air passes on the way to the acinar airways from the atmosphere, the reduction ratio of diameter is closely related to the minimization of viscous dissipation. Such a principle is formulated as the Hess-Murray law. However, in acinar airways, where oxygen transfer to alveolae occurs, the diameter reduction with progressive generations is more moderate than in conducting airways. Noting that the dominant transfer mechanism in acinar airways is diffusion rather than advection, unlike conducting airways, we construct a mathematical model for oxygen transfer through a series of acinar airways. Our model allows us to predict the optimal airway reduction ratio that maximizes the oxygen transfer in a finite airway volume, thereby rationalizing the observed airway reduction ratio in acinar airways.

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

Alfonso Hernandez, Laura; Nelson, Tammie Renee; Gelin, Maxim F.

The interchromophoric energy-transfer pathways between weakly coupled units in a π-conjugated phenylene–ethynylene macrocycle and its half-ring analogue have been investigated using the nonadiabatic excited-state molecular dynamics approach. To track the flow of electronic transition density between macrocycle units, we formulate a transition density flux analysis adapted from the statistical minimum flow method previously developed to investigate vibrational energy flow. Following photoexcitation, transition density is primarily delocalized on two chromophore units and the system undergoes ultrafast energy transfer, creating a localized excited state on a single unit. In the macrocycle, distinct chromophore units donate transition density to a single acceptor unitmore » but do not interchange transition density among each other. We find that energy transfer in the macrocycle is slower than in the corresponding half ring because of the presence of multiple interfering energy-transfer pathways. Finally, simulation results are validated by modeling the fluorescence anisotropy decay.« less

Number-theoretic nature of communication in quantum spin systems.

PubMed

Godsil, Chris; Kirkland, Stephen; Severini, Simone; Smith, Jamie

2012-08-03

The last decade has witnessed substantial interest in protocols for transferring information on networks of quantum mechanical objects. A variety of control methods and network topologies have been proposed, on the basis that transfer with perfect fidelity-i.e., deterministic and without information loss-is impossible through unmodulated spin chains with more than a few particles. Solving the original problem formulated by Bose [Phys. Rev. Lett. 91, 207901 (2003)], we determine the exact number of qubits in unmodulated chains (with an XY Hamiltonian) that permit transfer with a fidelity arbitrarily close to 1, a phenomenon called pretty good state transfer. We prove that this happens if and only if the number of nodes is n = p - 1, 2p - 1, where p is a prime, or n = 2(m) - 1. The result highlights the potential of quantum spin system dynamics for reinterpreting questions about the arithmetic structure of integers and, in this case, primality.

Modeling and Simulation of Bus Dispatching Policy for Timed Transfers on Signalized Networks

NASA Astrophysics Data System (ADS)

Cho, Hsun-Jung; Lin, Guey-Shii

2007-12-01

The major work of this study is to formulate the system cost functions and to integrate the bus dispatching policy with signal control. The integrated model mainly includes the flow dispersion model for links, signal control model for nodes, and dispatching control model for transfer terminals. All such models are inter-related for transfer operations in one-center transit network. The integrated model that combines dispatching policies with flexible signal control modes can be applied to assess the effectiveness of transfer operations. It is found that, if bus arrival information is reliable, an early dispatching decision made at the mean bus arrival times is preferable. The costs for coordinated operations with slack times are relatively low at the optimal common headway when applying adaptive route control. Based on such findings, a threshold function of bus headway for justifying an adaptive signal route control under various time values of auto drivers is developed.

Towards a theory of stochastic vorticity-augmentation. [tornado model

NASA Technical Reports Server (NTRS)

Liu, V. C.

1977-01-01

A new hypothesis to account for the formation of tornadoes is presented. An elementary one-dimensional theory is formulated for vorticity transfer between an ambient sheared wind and a transverse penetrating jet. The theory points out the relevant quantities to be determined in describing the present stochastic mode of vorticity augmentation.

Multimedia Learning: Cognitive Individual Differences and Display Design Techniques Predict Transfer Learning with Multimedia Learning Modules

ERIC Educational Resources Information Center

Austin, Katherine A.

2009-01-01

In the wake of the information explosion and rapidly progressing technology [Mayer, R. E. (2001). "Multimedia learning". Cambridge: University Press] formulated a theory that focused on human cognition, rather than technology capacity and features. By measuring the effect of cognitive individual differences and display design manipulations on…

Multivariable control of a twin lift helicopter system using the LQG/LTR design methodology

NASA Technical Reports Server (NTRS)

Rodriguez, A. A.; Athans, M.

1986-01-01

Guidelines for developing a multivariable centralized automatic flight control system (AFCS) for a twin lift helicopter system (TLHS) are presented. Singular value ideas are used to formulate performance and stability robustness specifications. A linear Quadratic Gaussian with Loop Transfer Recovery (LQG/LTR) design is obtained and evaluated.

The role of silver in self-lubricating coatings for use at extreme temperatures

NASA Technical Reports Server (NTRS)

Sliney, H. E.

1985-01-01

The advantages and disadvantages of elemental silver as a tribological material are discussed. It is demonstrated that the relatively high melting point of 961 deg C, softness, marked plasticity, and thermochemical stability of silver combine to make this metal useful in thin film solid lubricant coatings over a wide temperature range. Disadvantages of silver during sliding, except when used as a thin film, are shown to be gross ploughing due to plastic deformation under load with associated high friction and excessive transfer to counterface surfaces. This transfer generates an irregular surface topography with consequent undesirable changes in bearing clearance distribution. Research to overcome these disadvantages of element silver is described. A comparison is made of the tribological behavior of pure silver with that of silver formulated with other metals and high-temperature solid lubricants. The composite materials are prepared by co-depositing the powdered components with an airbrush followed by furnace heat treatment or by plasma-spraying. Composite coatings were formulated which are shown to be self-lubricating over repeated, temperature cycles from low temperature to about 900 deg C.

The use of silver in self-lubricating coatings for extreme temperatures

NASA Technical Reports Server (NTRS)

Sliney, H. E.

1986-01-01

The advantages and disadvantages of elemental silver as a tribological material are discussed. It is demonstrated that the relatively high melting point of 961 deg C, softness, marked plasticity, and thermochemical stability of silver combine to make this metal useful in thin film solid lubricant coatings over a wide temperature range. Disadvantages of silver during sliding, except when used as a thin film, are shown to be gross ploughing due to plastic deformation under load with associated high friction and excessive transfer to counterface surfaces. This transfer generates an irregular surface topography with consequent undesirable changes in bearing clearance distribution. Research to overcome these disadvantages of element silver is described. A comparison is made of the tribological behavior of pure silver with that of silver formulated with other metals and high-temperature solid lubricants. The composite materials are prepared by co-depositing the powdered components with an airbrush followed by furnace heat treatment or by plasma-spraying. Composite coatings were formulated which are shown to be self-lubricating over repeated, temperature cycles from low temperature to about 900 deg C.

Nonlinear resistivity for magnetohydrodynamical models

DOE PAGES

Lingam, M.; Hirvijoki, E.; Pfefferlé, D.; ...

2017-04-20

A new formulation of the plasma resistivity that stems from the collisional momentum-transfer rate between electrons and ions is presented. The resistivity computed herein is shown to depend not only on the temperature and density but also on all other polynomial velocity-space moments of the distribution function, such as the pressure tensor and heat flux vector. The full expression for the collisional momentum-transfer rate is determined and is used to formulate the nonlinear anisotropic resistivity. The new formalism recovers the Spitzer resistivity, as well as the concept of thermal force if the heat flux is assumed to be proportional tomore » a temperature gradient. Furthermore, if the pressure tensor is related to viscous stress, the latter enters the expression for the resistivity. The relative importance of the nonlinear term(s) with respect to the well-established electron inertia and Hall terms is also examined. Lastly, the subtle implications of the nonlinear resistivity, and its dependence on the fluid variables, are discussed in the context of magnetized plasma environments and phenomena such as magnetic reconnection.« less

Pilot-scale biopesticide production by Bacillus thuringiensis subsp. kurstaki using starch industry wastewater as raw material.

PubMed

Ndao, Adama; Sellamuthu, Balasubramanian; Gnepe, Jean R; Tyagi, Rajeshwar D; Valero, Jose R

2017-09-02

Pilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (K L a) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material.

A ’Multiple Pivoting’ Algorithm for Goal-Interval Programming Formulations.

DTIC Science & Technology

1980-03-01

jotso _P- ,- Research Report CCS 355 A "MULTIPLE PIVOTING" ALGORITHM FOR GOAL-INTERVAL PROGRAMMING FORMULATIONS by R. Armstrong* A. Charnes*W. Cook...J. Godfrey*** March 1980 *The University of Texas at Austin **York University, Downsview, Ontario, Canada ***Washington, DC This research was partly...areas. However, the main direction of goal programing research has been in formulating models instead of seeking procedures that would provide

Mathematical Modeling of Diverse Phenomena

NASA Technical Reports Server (NTRS)

Howard, J. C.

1979-01-01

Tensor calculus is applied to the formulation of mathematical models of diverse phenomena. Aeronautics, fluid dynamics, and cosmology are among the areas of application. The feasibility of combining tensor methods and computer capability to formulate problems is demonstrated. The techniques described are an attempt to simplify the formulation of mathematical models by reducing the modeling process to a series of routine operations, which can be performed either manually or by computer.

Computations of soot and and NO sub x emissions from gas turbine combustors

NASA Technical Reports Server (NTRS)

Srivatsa, S. K.

1982-01-01

An analytical program was conducted to compute the soot and NOx emissions from a combustor and the radiation heat transfer to the combustor walls. The program involved the formulation of an emission and radiation model and the incorporation of this model into the Garrett 3-D Combustor Perfomance Computer Program. Computations were performed for the idle, cruise, and take-off conditions of a JT8D can combustor. The predicted soot and NOx emissions and the radiation heat transfer to the combustor walls agree reasonably well with the limited experimental data available.

The initial pharmaceutical development of an artesunate/amodiaquine oral formulation for the treatment of malaria: a public-private partnership.

PubMed

Lacaze, Catherine; Kauss, Tina; Kiechel, Jean-René; Caminiti, Antonella; Fawaz, Fawaz; Terrassin, Laurent; Cuart, Sylvie; Grislain, Luc; Navaratnam, Visweswaran; Ghezzoul, Bellabes; Gaudin, Karen; White, Nick J; Olliaro, Piero L; Millet, Pascal

2011-05-23

Artemisinin-based combination therapy is currently recommended worldwide for the treatment of uncomplicated malaria. Fixed-dose combinations are preferred as they favour compliance. This paper reports on the initial phases of the pharmaceutical development of an artesunate-amodiaquine (ASAQ) bilayer co-formulation tablet, undertaken following pre-formulation studies by a network of scientists and industrials from institutions of both industrialized and low income countries. Pharmaceutical development was performed by a research laboratory at the University Bordeaux Segalen, School of Pharmacy, for feasibility and early stability studies of various drug formulations, further transferred to a company specialized in pharmaceutical development, and then provided to another company for clinical batch manufacturing. The work was conducted by a regional public-private not-for-profit network (TropiVal) within a larger Public Private partnership (the FACT project), set up by WHO/TDR, Médecins Sans Frontières and the Drugs for Neglected Disease initiative (DNDi). The main pharmaceutical goal was to combine in a solid oral form two incompatible active principles while preventing artesunate degradation under tropical conditions. Several options were attempted and failed to provide satisfactory stability results: incorporating artesunate in the external phase of the tablets, adding a pH regulator, alcoholic wet granulation, dry granulation, addition of an hydrophobic agent, tablet manufacturing in controlled conditions. However, long-term stability could be achieved, in experimental batches under GMP conditions, by physical separation of artesunate and amodiaquine in a bilayer co-formulation tablet in alu-alu blisters. Conduction of the workplan was monitored by DNDi. Collaborations between research and industrial groups greatly accelerated the process of development of the bi-layered ASAQ tablet. Lack of public funding was the main obstacle hampering the development process, and no intellectual property right was claimed. This approach resulted in a rapid technology transfer to the drug company Sanofi-Aventis, finalizing the process of development, registration and WHO pre-qualification of the fixed-dose co-formulation together with DNDi. The bi-layered tablet is made available under the names of Coarsucam® and Artesunate amodiaquine Winthrop®, Sanofi-Aventis. The issue related to the difficulty of public institutions to valorise their participation in such initiative by lack of priority and funding of applied research is discussed.

The initial pharmaceutical development of an artesunate/amodiaquine oral formulation for the treatment of malaria: a public-private partnership

PubMed Central

2011-01-01

Background Artemisinin-based combination therapy is currently recommended worldwide for the treatment of uncomplicated malaria. Fixed-dose combinations are preferred as they favour compliance. This paper reports on the initial phases of the pharmaceutical development of an artesunate-amodiaquine (ASAQ) bilayer co-formulation tablet, undertaken following pre-formulation studies by a network of scientists and industrials from institutions of both industrialized and low income countries. Methods Pharmaceutical development was performed by a research laboratory at the University Bordeaux Segalen, School of Pharmacy, for feasibility and early stability studies of various drug formulations, further transferred to a company specialized in pharmaceutical development, and then provided to another company for clinical batch manufacturing. The work was conducted by a regional public-private not-for-profit network (TropiVal) within a larger Public Private partnership (the FACT project), set up by WHO/TDR, Médecins Sans Frontières and the Drugs for Neglected Disease initiative (DNDi). Results The main pharmaceutical goal was to combine in a solid oral form two incompatible active principles while preventing artesunate degradation under tropical conditions. Several options were attempted and failed to provide satisfactory stability results: incorporating artesunate in the external phase of the tablets, adding a pH regulator, alcoholic wet granulation, dry granulation, addition of an hydrophobic agent, tablet manufacturing in controlled conditions. However, long-term stability could be achieved, in experimental batches under GMP conditions, by physical separation of artesunate and amodiaquine in a bilayer co-formulation tablet in alu-alu blisters. Conduction of the workplan was monitored by DNDi. Conclusions Collaborations between research and industrial groups greatly accelerated the process of development of the bi-layered ASAQ tablet. Lack of public funding was the main obstacle hampering the development process, and no intellectual property right was claimed. This approach resulted in a rapid technology transfer to the drug company Sanofi-Aventis, finalizing the process of development, registration and WHO pre-qualification of the fixed-dose co-formulation together with DNDi. The bi-layered tablet is made available under the names of Coarsucam® and Artesunate amodiaquine Winthrop®, Sanofi-Aventis. The issue related to the difficulty of public institutions to valorise their participation in such initiative by lack of priority and funding of applied research is discussed. PMID:21605361

A simple exposure-time theory for all time-nonlocal transport formulations and beyond.

NASA Astrophysics Data System (ADS)

Ginn, T. R.; Schreyer, L. G.

2016-12-01

Anomalous transport or better put, anomalous non-transport, of solutes or flowing water or suspended colloids or bacteria etc. has been the subject of intense analyses with multiple formulations appearing in scientific literature from hydrology to geomorphology to chemical engineering, to environmental microbiology to mathematical physics. Primary focus has recently been on time-nonlocal mass conservation formulations such as multirate mass transfer, fractional-time advection-dispersion, continuous-time random walks, and dual porosity modeling approaches, that employ a convolution with a memory function to reflect respective conceptual models of delays in transport. These approaches are effective or "proxy" ones that do not always distinguish transport from immobilzation delays, are generally without connection to measurable physicochemical properties, and involve variously fractional calculus, inverse Laplace or Fourier transformations, and/or complex stochastic notions including assumptions of stationarity or ergodicity at the observation scale. Here we show a much simpler approach to time-nonlocal (non-)transport that is free of all these things, and is based on expressing the memory function in terms of a rate of mobilization of immobilized mass that is a function of the continguous time immobilized. Our approach treats mass transfer completely independently from the transport process, and it allows specification of actual immobilization mechanisms or delays. To our surprize we found that for all practical purposes any memory function can be expressed this way, including all of those associated with the multi-rate mass transfer approaches, original powerlaw, different truncated powerlaws, fractional-derivative, etc. More intriguing is the fact that the exposure-time approach can be used to construct heretofore unseen memory functions, e.g., forms that generate oscillating tails of breakthrough curves such as may occur in sediment transport, forms for delay-differential equations, and so on. Because the exposure-time approach is both simple and localized, it provides a promising platform for launching forays into non-Markovian and/or nonlinear processes and into upscaling age-dependent multicomponent reaction systems.

A comprehensive evaluation of different radiation models in a gas turbine combustor under conditions of oxy-fuel combustion with dry recycle

NASA Astrophysics Data System (ADS)

Kez, V.; Liu, F.; Consalvi, J. L.; Ströhle, J.; Epple, B.

2016-03-01

The oxy-fuel combustion is a promising CO2 capture technology from combustion systems. This process is characterized by much higher CO2 concentrations in the combustion system compared to that of the conventional air-fuel combustion. To accurately predict the enhanced thermal radiation in oxy-fuel combustion, it is essential to take into account the non-gray nature of gas radiation. In this study, radiation heat transfer in a 3D model gas turbine combustor under two test cases at 20 atm total pressure was calculated by various non-gray gas radiation models, including the statistical narrow-band (SNB) model, the statistical narrow-band correlated-k (SNBCK) model, the wide-band correlated-k (WBCK) model, the full spectrum correlated-k (FSCK) model, and several weighted sum of gray gases (WSGG) models. Calculations of SNB, SNBCK, and FSCK were conducted using the updated EM2C SNB model parameters. Results of the SNB model are considered as the benchmark solution to evaluate the accuracy of the other models considered. Results of SNBCK and FSCK are in good agreement with the benchmark solution. The WBCK model is less accurate than SNBCK or FSCK. Considering the three formulations of the WBCK model, the multiple gases formulation is the best choice regarding the accuracy and computational cost. The WSGG model with the parameters of Bordbar et al. (2014) [20] is the most accurate of the three investigated WSGG models. Use of the gray WSSG formulation leads to significant deviations from the benchmark data and should not be applied to predict radiation heat transfer in oxy-fuel combustion systems. A best practice to incorporate the state-of-the-art gas radiation models for high accuracy of radiation heat transfer calculations at minimal increase in computational cost in CFD simulation of oxy-fuel combustion systems for pressure path lengths up to about 10 bar m is suggested.

Pickering emulsions for skin decontamination.

PubMed

Salerno, Alicia; Bolzinger, Marie-Alexandrine; Rolland, Pauline; Chevalier, Yves; Josse, Denis; Briançon, Stéphanie

2016-08-01

This study aimed at developing innovative systems for skin decontamination. Pickering emulsions, i.e. solid-stabilized emulsions, containing silica (S-PE) or Fuller's earth (FE-PE) were formulated. Their efficiency for skin decontamination was evaluated, in vitro, 45min after an exposure to VX, one of the most highly toxic chemical warfare agents. Pickering emulsions were compared to FE (FE-W) and silica (S-W) aqueous suspensions. PE containing an oil with a similar hydrophobicity to VX should promote its extraction. All the formulations reduced significantly the amount of VX quantified on and into the skin compared to the control. Wiping the skin surface with a pad already allowed removing more than half of VX. FE-W was the less efficient (85% of VX removed). The other formulations (FE-PE, S-PE and S-W) resulted in more than 90% of the quantity of VX removed. The charge of particles was the most influential factor. The low pH of formulations containing silica favored electrostatic interactions of VX with particles explaining the better elimination from the skin surface. Formulations containing FE had basic pH, and weak interactions with VX did not improve the skin decontamination. However, these low interactions between VX and FE promote the transfer of VX into the oil droplets in the FE-PE. Copyright © 2016 Elsevier B.V. All rights reserved.

Dispersibility of lactose fines as compared to API in dry powders for inhalation.

PubMed

Thalberg, Kyrre; Åslund, Simon; Skogevall, Marcus; Andersson, Patrik

2016-05-17

This work investigates the dispersion performance of fine lactose particles as function of processing time, and compares it to the API, using Beclomethasone Dipropionate (BDP) as model API. The total load of fine particles is kept constant in the formulations while the proportions of API and lactose fines are varied. Fine particle assessment demonstrates that the lactose fines have higher dispersibility than the API. For standard formulations, processing time has a limited effect on the Fine Particle Fraction (FPF). For formulations containing magnesium stearate (MgSt), FPF of BDP is heavily influenced by processing time, with an initial increase, followed by a decrease at longer mixing times. An equation modeling the observed behavior is presented. Surprisingly, the dispersibility of the lactose fines present in the same formulation remains unaffected by mixing time. Magnesium analysis demonstrates that MgSt is transferred to the fine particles during the mixing process, thus lubrication both BDP and lactose fines, which leads to an increased FPF. Dry particle sizing of the formulations reveals a loss of fine particles at longer mixing times. Incorporation of fine particles into the carrier surfaces is believed to be behind this, and is hence a mechanism of importance as regards the dispersion performance of dry powders for inhalation. Copyright © 2016 Elsevier B.V. All rights reserved.

Context transfer in reinforcement learning using action-value functions.

PubMed

Mousavi, Amin; Nadjar Araabi, Babak; Nili Ahmadabadi, Majid

2014-01-01

This paper discusses the notion of context transfer in reinforcement learning tasks. Context transfer, as defined in this paper, implies knowledge transfer between source and target tasks that share the same environment dynamics and reward function but have different states or action spaces. In other words, the agents learn the same task while using different sensors and actuators. This requires the existence of an underlying common Markov decision process (MDP) to which all the agents' MDPs can be mapped. This is formulated in terms of the notion of MDP homomorphism. The learning framework is Q-learning. To transfer the knowledge between these tasks, the feature space is used as a translator and is expressed as a partial mapping between the state-action spaces of different tasks. The Q-values learned during the learning process of the source tasks are mapped to the sets of Q-values for the target task. These transferred Q-values are merged together and used to initialize the learning process of the target task. An interval-based approach is used to represent and merge the knowledge of the source tasks. Empirical results show that the transferred initialization can be beneficial to the learning process of the target task.

Context Transfer in Reinforcement Learning Using Action-Value Functions

PubMed Central

Mousavi, Amin; Nadjar Araabi, Babak; Nili Ahmadabadi, Majid

2014-01-01

This paper discusses the notion of context transfer in reinforcement learning tasks. Context transfer, as defined in this paper, implies knowledge transfer between source and target tasks that share the same environment dynamics and reward function but have different states or action spaces. In other words, the agents learn the same task while using different sensors and actuators. This requires the existence of an underlying common Markov decision process (MDP) to which all the agents' MDPs can be mapped. This is formulated in terms of the notion of MDP homomorphism. The learning framework is Q-learning. To transfer the knowledge between these tasks, the feature space is used as a translator and is expressed as a partial mapping between the state-action spaces of different tasks. The Q-values learned during the learning process of the source tasks are mapped to the sets of Q-values for the target task. These transferred Q-values are merged together and used to initialize the learning process of the target task. An interval-based approach is used to represent and merge the knowledge of the source tasks. Empirical results show that the transferred initialization can be beneficial to the learning process of the target task. PMID:25610457

Transient hot-film sensor response in a shock tube

NASA Technical Reports Server (NTRS)

Roberts, A. S., Jr.; Ortgies, K. R.; Gartenberg, E.

1989-01-01

Shock tube experiments were performed to determine the response of a hot-film sensor, mounted flush on the side wall of a shock tube, to unsteady flow behind a normal shock wave. The present experiments attempt to isolate the response of the anemometer due only to the change in convective heat transfer at the hot-film surface. The experiments, performed at low supersonic shock speeds in air, are described along with the data acquisition procedure. The change in convective heat transfer is deduced from the data and the results are compared with those from transient boundary layer theory and another set of experimental results. Finally, a transient local heat transfer coefficient is formulated for use as the forcing function in a hot-film sensor instrument model simulation.

A Many-Objective Approach to Developing Adaptive Water Supply Portfolios in the 'Research Triangle' Region of North Carolina

NASA Astrophysics Data System (ADS)

Zeff, H. B.; Kasprzyk, J. R.; Reed, P. M.; Characklis, G. W.

2012-12-01

This study uses many-objective evolutionary optimization to quantify the tradeoffs water utilities face when developing flexible water shortage response plans. Alternatives to infrastructure development, such as temporary demand management programs and inter-utility water transfer agreements, allow local water providers to develop portfolios of water supply options capable of adapting to changing hydrologic conditions and growing water demand. The extent to which these options are implemented will be determined by a number of conflicting operational and financial considerations. An integrated reservoir simulation model including four large water utilities in the 'Research Triangle' region of North Carolina is used to evaluate the potential tradeoffs resulting from regional demands on shared infrastructure, customer concerns, and the financial uncertainty caused by the intermittent and irregular nature of drought. Instead of providing one optimal solution, multi-objective evolutionary algorithms (MOEAs) use the concept of non-dominations to discover a set of portfolio options in which no solution is inferior to any other solution in all objectives. Interactive visual analytics enable water providers to explore these tradeoffs and develop water shortage response plans tailored to their individual circumstances. The simulation model is evaluated under a number of different formulations to help identify and visualize the impacts of water efficiency, revenue/cost variability, consumer effects, and inter-utility cooperation. The different problems are formulated by adding portfolio options and objectives in such a way that the lower dimensional problem formulations are sub-sets of the full formulation. The full formulation considers reservoir reliability, water use restriction frequency, total water transfer allotment, total costs, revenue/cost variability, and additional consumer losses during restrictions. The simulation results highlight the inadequacy of lower order, cost-benefit type analyses to evaluate water management techniques as they move beyond the construction of large storage infrastructure. This work can help water providers develop the analytical tools to evaluate complex, adaptive techniques that are becoming more attractive in an era of growing municipal demand, risking infrastructure costs, and uncertain hydrology.

Establishing a theory for deuteron-induced surrogate reactions

NASA Astrophysics Data System (ADS)

Potel, G.; Nunes, F. M.; Thompson, I. J.

2015-09-01

Background: Deuteron-induced reactions serve as surrogates for neutron capture into compound states. Although these reactions are of great applicability, no theoretical efforts have been invested in this direction over the last decade. Purpose: The goal of this work is to establish on firm grounds a theory for deuteron-induced neutron-capture reactions. This includes formulating elastic and inelastic breakup in a consistent manner. Method: We describe this process both in post- and prior-form distorted wave Born approximation following previous works and discuss the differences in the formulation. While the convergence issues arising in the post formulation can be overcome in the prior formulation, in this case one still needs to take into account additional terms due to nonorthogonality. Results: We apply our method to the 93Nb(d ,p )X at Ed=15 and 25 MeV and are able to obtain a good description of the data. We look at the various partial wave contributions, as well as elastic versus inelastic contributions. We also connect our formulation with transfer to neutron bound states. Conclusions: Our calculations demonstrate that the nonorthogonality term arising in the prior formulation is significant and is at the heart of the long-standing controversy between the post and the prior formulations of the theory. We also show that the cross sections for these reactions are angular-momentum dependent and therefore the commonly used Weisskopf limit is inadequate. Finally, we make important predictions for the relative contributions of elastic breakup and nonelastic breakup and call for elastic-breakup measurements to further constrain our model.

Establishing a theory for deuteron induced surrogate reactions

DOE PAGES

Potel, G.; Nunes, F. M.; Thompson, I. J.

2015-09-18

Background: Deuteron-induced reactions serve as surrogates for neutron capture into compound states. Although these reactions are of great applicability, no theoretical efforts have been invested in this direction over the last decade. Purpose: The goal of this work is to establish on firm grounds a theory for deuteron-induced neutron-capture reactions. This includes formulating elastic and inelastic breakup in a consistent manner. Method: We describe this process both in post- and prior-form distorted wave Born approximation following previous works and discuss the differences in the formulation. While the convergence issues arising in the post formulation can be overcome in the priormore » formulation, in this case one still needs to take into account additional terms due to nonorthogonality. Results: We apply our method to the Nb93(d,p)X at Ed=15 and 25 MeV and are able to obtain a good description of the data. We then look at the various partial wave contributions, as well as elastic versus inelastic contributions. We also connect our formulation with transfer to neutron bound states.Conclusions: Our calculations demonstrate that the nonorthogonality term arising in the prior formulation is significant and is at the heart of the long-standing controversy between the post and the prior formulations of the theory. We also show that the cross sections for these reactions are angular-momentum dependent and therefore the commonly used Weisskopf limit is inadequate. We finally make important predictions for the relative contributions of elastic breakup and nonelastic breakup and call for elastic-breakup measurements to further constrain our model.« less

Recent advances in developing ophthalmic formulations: a patent review.

PubMed

Lu, Guang Wei

2010-01-01

In an effort to improve the drug solubility, stability and/or ocular bioavailability of ophthalmic formulations,various approaches have been explored in the recent past. Additionally, different formulations have been investigated in order to seek those preservative systems that are more tolerable to the ocular tissue. Over the past ten years, inventions in ophthalmic formulations directed toward front-of-eye instillations have concentrated in the areas of new excipients' applications, novel and combined use of conventional excipients, and developments of novel dosage forms. Among these areas, applications of polymeric excipients, cyclodextrins and stabilized chloride dioxide (SCD) have been the most actively studied fields. In addition, oil-in-water (O/W) emulsions have been becoming more popular as an ophthalmic dosage form due to the potentials in increasing drug solubility, stabilizing active pharmaceutical ingredients (APIs), improving ocular tolerance, and providing palliative effects. Some of these innovations from the past decade have the capability of leading to new commercial products. This patent review has a useful knowledge in the advancement for treating various ophthalmic diseases.

Improving Students' Transfer of Learning among Subject Areas through the Use of an Integrated Curriculum and Alternative Assessment.

ERIC Educational Resources Information Center

Boidy, Tish; Moran, Michelle

An intervention program sought to improve third- and fifth- grade students' ability to transfer learning among subject areas and to apply their learning to everyday occurrences. Surveys and interviews revealed the lack of student transference of knowledge among subject areas; teacher surveys and an interview with the curriculum director provided…

Transfer of knowledge and skills: some implications for nursing and nurse education.

PubMed

Lauder, W; Reynolds, W; Angus, N

1999-08-01

The construct of transfer has enormous importance to nursing as it begins to highlight potential problems in the transfer of knowledge and skills from the campus to the clinical area, from one part of the clinical area to another (e.g. surgical to medical), and from community to the clinical area. Thus, any adequate conceptualization of transfer must account for problems of practice-practice transfer as well as theory-practice transfer. These potential problems are the concern of educators, students and managers who have a responsibility for agency nurses and bank nurses who may find themselves in different specialities on a regular basis. Transfer has relevance to a whole raft of other issues ranging from the application of theories to nursing practice, through to the validity of claims that courses which develop intellectual skills prepare nurses for lifelong learning.

Spreading of a Lidocaine Formulation on Microneedle-Treated Skin.

PubMed

Nayak, Atul; Das, Diganta B; Chao, Tzu C; Starov, Victor M

2015-12-01

The spreadability of a liquid drug formulation on skin is an indication of it either remaining stationary or distributing (spreading) as a droplet. Factors determining droplet spreadability of the formulation are spreading area, diameter of the droplet base, viscosity of the liquid, contact angle, volume of droplet on skin and any others. The creation of microcavities from the application of microneedle (MN) has the potential to control droplet spreading, and hence, target specific areas of skin for drug delivery. However, there is little work that demonstrates spreading of liquid drug formulation on MN-treated skin. Below, spreading of a lidocaine hydrogel formulation and lidocaine solution (reference liquid) on porcine skin is investigated over MN-treated skin. Controlled spreadability was achieved with the lidocaine hydrogel on MN-treated skin as compared with lidocaine solution. It was observed that the droplet spreading parameters such as spreading radius, droplet height and dynamic contact angle were slightly lower for the lidocaine hydrogel than the lidocaine solution on skin. Also, the lidocaine hydrogel on MN-treated skin resulted in slower dynamic reduction of droplet height, contact angle and reduced time taken in attaining static advancing droplets because of the MN microcavities. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

(Quasi-) 2D aggregation of polystyrene-b-dextran at the air-water interface.

PubMed

Bosker, Wouter T E; Cohen Stuart, Martien A; Norde, Willem

2013-02-26

Polystyrene-b-dextran (PS-b-Dextran) copolymers can be used to prepare dextran brushes at solid surfaces, applying Langmuir-Blodgett deposition. When recording the interfacial pressure versus area isotherms of a PS-b-Dextran monolayer, time-dependent hysteresis was observed upon compression and expansion. We argue that this is due to (quasi-) 2D aggregation of the copolymer at the air-water surface, with three contributions. First, at large area per molecule, a zero surface pressure is measured; we ascribe this to self-assembly of block copolymers into surface micelles. At intermediate area we identify a second regime ("desorption regime") where aggregation into large patches occurs due to van der Waals attraction between PS blocks. At high surface pressure ("brush regime") we observe hysteretic behavior attributed to H-bonding between dextran chains. When compared to hysteresis of other amphiphilic diblock copolymers (also containing PS, e.g., polystyrene-b-poly(ethylene oxide)) a general criterion can be formulated concerning the extent of hysteresis: when the hydrophobic (PS) block is of equal size as (or bigger than) the hydrophilic block, the hysteresis is maximal. The (quasi-) 2D aggregation of PS-b-Dextran has significant implications for the preparation of dextran brushes at solid surfaces using Langmuir-Blodgett deposition. For each grafting density the monolayer needs to relax, up to several hours, prior to transfer.

Coastal Planning for Sustainable Maritime Management

NASA Astrophysics Data System (ADS)

Hakim, F.; Santoso, E. B.; Supriharjo, R.

2017-08-01

The Kendari Bay has a unique asset as a tourist attraction for the residents of the city of Kendari. The coastal area with all its potential like as a green open space, mangrove forests, the play area, is still a main destination to attract visitors. The function of Kendari Bay area as a tourist attraction makes this area as a place that has potential as a center of the economic vibrant and social interaction. Unfortunately, the arrangement of the area has not been done so that the integrated development of the region is not optimal. Therefore, it is important to promote a concept of area development as a tourist destination of coastal areas in order to improve function of the area. The concept of the coastal development area of Kendari Bay as tourist areas is formulated by the development criteria that influence to capable of attracting tourists. The criteria is formulated by the factors that play a role in the development of tourist areas, further exploration by qualitative descriptive analysis based on the information respondents. Fixation of the results of the criteria development was done with descriptive analysis assessed based on theoretically references through literature and regulations regarding the criteria for the development of tourism. To formulating the concept of tourism development used qualitative descriptive analysis technique with validation using triangulation techniques. The concept of tourism development based on the potential of the region is divided into three zones, namely area development of the core zone, direct supporting zone and indirect supporting zone. The macro spatial concept is necessary for the development of the area through the improvement of accessibility to tourist attraction, while the micro spatial concept includes improvements and additions to the activity in each zone to provide the convenience facilities for the tourists.

Preparation and evaluation of a novel star-shaped polyacid-constructed dental glass-ionomer system.

PubMed

Howard, Leah; Weng, Yiming; Xie, Dong

2014-06-01

The objective of this study was to synthesize and characterize novel star-shaped poly(acrylic acid-co-itaconic acid)s via chain-transfer radical polymerization technique, use these polyacids to formulate the resin-modified glass-ionomer cements, and evaluate the mechanical strengths of the formed cements The star-shaped poly(acrylic acid-co-itaconic acid)s were synthesized via a chain-transfer radical polymerization reaction using a newly synthesized star-shaped chain-transfer agent. The effects of MW, GM-tethering ratio, P/L ratio and aging on the compressive properties of the formed experimental cements were studied. Compressive, diametral tensile as well as flexural strengths were evaluated and compared to those of Fuji II and Fuji II LC cements. The star-shaped polyacids showed significantly lower viscosities in water as compared to their linear counterparts. The cements formulated with these novel polyacids showed significantly improved mechanical strengths i.e., 49% in yield strength, 41% in modulus, 25% in CS, 20% in DTS and 36% in FS, higher than commercial Fuji II LC. After aging in water for 30 days, the compressive strengths of the experimental cements were significantly changed with an increase of 29% in YS, 19% in modulus as well as 23% in CS and a decrease of 5% in toughness, indicating that aging in water enhances the salt-bridge formation and increases brittleness. A novel light-cured glass-ionomer cement system composed of the star-shaped poly(carboxylic acid)s has been developed via a cost-effective and time-efficient chain-transfer radical polymerization. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

A globally nonsingular quaternion-based formulation for all-electric satellite trajectory optimization

NASA Astrophysics Data System (ADS)

Libraro, Paola

The general electric propulsion orbit-raising maneuver of a spacecraft must contend with four main limiting factors: the longer time of flight, multiple eclipses prohibiting continuous thrusting, long exposure to radiation from the Van Allen belt and high power requirement of the electric engines. In order to optimize a low-thrust transfer with respect to these challenges, the choice of coordinates and corresponding equations of motion used to describe the kinematical and dynamical behavior of the satellite is of critical importance. This choice can potentially affect the numerical optimization process as well as limit the set of mission scenarios that can be investigated. To increase the ability to determine the feasible set of mission scenarios able to address the challenges of an all-electric orbit-raising, a set of equations free of any singularities is required to consider a completely arbitrary injection orbit. For this purpose a new quaternion-based formulation of a spacecraft translational dynamics that is globally nonsingular has been developed. The minimum-time low-thrust problem has been solved using the new set of equations of motion inside a direct optimization scheme in order to investigate optimal low-thrust trajectories over the full range of injection orbit inclinations between 0 and 90 degrees with particular focus on high-inclinations. The numerical results consider a specific mission scenario in order to analyze three key aspects of the problem: the effect of the initial guess on the shape and duration of the transfer, the effect of Earth oblateness on transfer time and the role played by, radiation damage and power degradation in all-electric minimum-time transfers. Finally trade-offs between mass and cost savings are introduced through a test case.

Exploring network operations for data and information networks

NASA Astrophysics Data System (ADS)

Yao, Bing; Su, Jing; Ma, Fei; Wang, Xiaomin; Zhao, Xiyang; Yao, Ming

2017-01-01

Barabási and Albert, in 1999, formulated scale-free models based on some real networks: World-Wide Web, Internet, metabolic and protein networks, language or sexual networks. Scale-free networks not only appear around us, but also have high qualities in the world. As known, high quality information networks can transfer feasibly and efficiently data, clearly, their topological structures are very important for data safety. We build up network operations for constructing large scale of dynamic networks from smaller scale of network models having good property and high quality. We focus on the simplest operators to formulate complex operations, and are interesting on the closeness of operations to desired network properties.

Biological assessment for the transfer of the DP land tract

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

Keller, D.C.

1996-10-01

The Department of Energy (DOE) is proposing to transfer to the County of Los Alamos up to 10-ha (25-ac) of federal land located in Technical Area-21 to be developed for commercial uses. Previous studies for the proposed land transfer area indicate that potential habitat for four threatened, endangered, and sensitive species occurs in or adjacent to the proposed land transfer area. These include the northern goshawk (federal species of concern), Mexican spotted owl (federal threatened), the spotted bat (federal species of concern, state threatened), die peregrine falcon (federal endangered, state endangered), and the. In order to determine the possible influencesmore » of the land transfer on these organisms, information from species-specific surveys was collected. These surveys were used to confirm the presence of these species or to infer their absence in or near the project area. It was concluded that none of die above mentioned species occur in the project area. Stretches of the stream channel within Los Alamos Canyon have been identified as palustrine and riverine, temporarily flooded wetlands. The proposed land transfer should not affect these wetlands.« less

Aeroplastic, New Composite Materials with Reduced Heat Transfer and Increased Flame Retardancy

NASA Technical Reports Server (NTRS)

Williams, Martha K.; Smith, Trent M.; Nichols, James D.; Roberson, Luke B.; Tate, Lanetra C.

2015-01-01

A new composite system formulated using commodity grade and engineered grade polymers. The composites can be fabricated into fibers, molded, or otherwise processed into useable articles. Use of this technology reduces the thermal conductivity and peak heat releases rates of the base polymer between 20%-50% while maintaining or enhancing the mechanical properties..

Analytic Formulation and Numerical Implementation of an Acoustic Pressure Gradient Prediction

NASA Technical Reports Server (NTRS)

Lee, Seongkyu; Brentner, Kenneth S.; Farassat, Fereidoun

2007-01-01

The scattering of rotor noise is an area that has received little attention over the years, yet the limited work that has been done has shown that both the directivity and intensity of the acoustic field may be significantly modified by the presence of scattering bodies. One of the inputs needed to compute the scattered acoustic field is the acoustic pressure gradient on a scattering surface. Two new analytical formulations of the acoustic pressure gradient have been developed and implemented in the PSU-WOPWOP rotor noise prediction code. These formulations are presented in this paper. The first formulation is derived by taking the gradient of Farassat's retarded-time Formulation 1A. Although this formulation is relatively simple, it requires numerical time differentiation of the acoustic integrals. In the second formulation, the time differentiation is taken inside the integrals analytically. The acoustic pressure gradient predicted by these new formulations is validated through comparison with the acoustic pressure gradient determined by a purely numerical approach for two model rotors. The agreement between analytic formulations and numerical method is excellent for both stationary and moving observers case.

Formulating entompathogens for control of boring beetles in avocado orchards

USDA-ARS?s Scientific Manuscript database

A foam formulation of Beauveria bassiana was adapted to control boring beetles in avocado orchards. The two geographically independent avocado growing areas in the United States are threatened by emerging diseases vectored by boring beetles. In the California growing region, Fusarium dieback is vect...

Small Systems and Limitations on the Use of Chemical Thermodynamics

NASA Astrophysics Data System (ADS)

Tovbin, Yu. K.

2018-01-01

Limitations on using chemical thermodynamics to describe small systems are formulated. These limitations follow from statistical mechanics for equilibrium and nonequilibrium processes and reflect (1) differences between characteristic relaxation times in momentum, energy, and mass transfer in different aggregate states of investigated systems; (2) achievements of statistical mechanics that allow us to determine criteria for the size of smallest region in which thermodynamics can be applied and the scale of the emergence of a new phase, along with criteria for the conditions of violating a local equilibrium. Based on this analysis, the main thermodynamic results are clarified: the phase rule for distorted interfaces, the sense and area of applicability of Gibbs's concept of passive forces, and the artificiality of Kelvin's equation as a result of limitations on the thermodynamic approach to considering small bodies. The wrongness of introducing molecular parameters into thermodynamic derivations, and the activity coefficient for an activated complex into the expression for a reaction rate constant, is demonstrated.

Pharmacy-based distribution system for enteral nutrition products.

PubMed

Craig, S A; Paulson, M F

1985-12-01

A hospital pharmacy department's implementation of enteral nutrition product distribution and its proposal for an enteral nutrition product admixture service are described. Responsibility for the distribution of enteral nutrition formulations was transferred from the central distribution department to the pharmacy after problems with inventory control, billing procedures, and inappropriate administration of enteral nutrition products were recognized by personnel from the central-distribution area and nutrition services. After additional problems were identified using a multi-disciplinary approach, the pharmacy department implemented an enteral nutrition product distribution system and developed an enteral nutrition product formulary. A proposal was developed for a pharmacy-based enteral nutrition admixture service, but implementation of this service was deferred because data from a cost-effectiveness evaluation and random bacteriologic monitoring did not justify adding the service. Pharmacy-based distribution and formulary control of enteral nutrition products alleviated problems with inaccurate patient charges and accumulation of stock on the nursing units. Pharmacists at this hospital hope to develop an enteral nutrition product admixture program that will result in cost savings for the institution.

Photocatalysis versus photosynthesis: A sensitivity analysis of devices for solar energy conversion and chemical transformations

DOE PAGES

Osterloh, Frank E.

2017-01-18

Here, the chemical literature often does not differentiate between photocatalytic (PC) and photosynthetic (PS) processes (including artificial photosynthesis) even though these reactions differ in their thermodynamics. Photocatalytic processes are thermodynamically downhill (ΔG < 0) and are merely accelerated by the catalyst, whereas photosynthetic processes are thermodynamically unfavorable (ΔG > 0) and require photochemical energy input to occur. Here we apply this differentiation to analyze the basic functions of PC and PS devices and to formulate design criteria for improved performance. As will be shown, the corresponding devices exhibit distinctly different sensitivities to their functional parameters. For example, under conditions ofmore » optimal light absorption, carrier lifetimes, and electrochemical rates, the performance of PCs is limited only by their surface area, while type 1 PS devices are limited by their carrier mobility and mass transport, and type 2 PS devices are limited by electrochemical charge-transfer selectivity. Strategies for the optimization of type 1 and 2 photosynthetic devices and photocatalysts are also discussed.« less

[Plastic reconstructive microsurgery in the elderly patient - Consensus statement of the German Speaking Working Group for Microsurgery of the Peripheral Nerves and Vessels].

PubMed

Ludolph, Ingo; Lehnhardt, Marcus; Arkudas, Andreas; Kneser, Ulrich; Pierer, Gerhard; Harder, Yves; Horch, Raymund E

2018-04-01

During the last two decades, understanding and experience of microsurgical reconstruction have increased. This is linked to improved instruments and technical devices, as well as to the increased number of available donor sites for microvascular flap transfer. If the indication is appropriate, it is now possible to perform personalised, safe and successful microsurgical reconstructions, almost independently of the patients' age. Despite these constant developments, there is little specific literature on microsurgery related to the specific problems of the elderly patient. During two consensus workshops organised by the DAM (German Speaking Working Group for Microsurgery of the Peripheral Nerves and Vessels), the latest findings and experience with microsurgical reconstruction in the elderly patient were presented by a group of experts and current recommendations were formulated. On the basis of these consensus workshops and the current literature, this article discusses important issues in this area. Georg Thieme Verlag KG Stuttgart · New York.

Photocatalysis versus photosynthesis: A sensitivity analysis of devices for solar energy conversion and chemical transformations

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

Osterloh, Frank E.

Here, the chemical literature often does not differentiate between photocatalytic (PC) and photosynthetic (PS) processes (including artificial photosynthesis) even though these reactions differ in their thermodynamics. Photocatalytic processes are thermodynamically downhill (ΔG < 0) and are merely accelerated by the catalyst, whereas photosynthetic processes are thermodynamically unfavorable (ΔG > 0) and require photochemical energy input to occur. Here we apply this differentiation to analyze the basic functions of PC and PS devices and to formulate design criteria for improved performance. As will be shown, the corresponding devices exhibit distinctly different sensitivities to their functional parameters. For example, under conditions ofmore » optimal light absorption, carrier lifetimes, and electrochemical rates, the performance of PCs is limited only by their surface area, while type 1 PS devices are limited by their carrier mobility and mass transport, and type 2 PS devices are limited by electrochemical charge-transfer selectivity. Strategies for the optimization of type 1 and 2 photosynthetic devices and photocatalysts are also discussed.« less

A Method for Optimal Load Dispatch of a Multi-zone Power System with Zonal Exchange Constraints

NASA Astrophysics Data System (ADS)

Hazarika, Durlav; Das, Ranjay

2018-04-01

This paper presented a method for economic generation scheduling of a multi-zone power system having inter zonal operational constraints. For this purpose, the generator rescheduling for a multi area power system having inter zonal operational constraints has been represented as a two step optimal generation scheduling problem. At first, the optimal generation scheduling has been carried out for the zone having surplus or deficient generation with proper spinning reserve using co-ordination equation. The power exchange required for the deficit zones and zones having no generation are estimated based on load demand and generation for the zone. The incremental transmission loss formulas for the transmission lines participating in the power transfer process among the zones are formulated. Using these, incremental transmission loss expression in co-ordination equation, the optimal generation scheduling for the zonal exchange has been determined. Simulation is carried out on IEEE 118 bus test system to examine the applicability and validity of the method.

Some Consequences of an Analysis of the Kelvin-Clausius Entropy Formulation Based on Traditional Axiomatics

NASA Astrophysics Data System (ADS)

Jesudason, Christopher G.

2003-09-01

Recently, there have appeared interesting correctives or challenges [Entropy 1999, 1, 111-147] to the Second law formulations, especially in the interpretation of the Clausius equivalent transformations, closely related in area to extensions of the Clausius principle to irreversible processes [Chem. Phys. Lett. 1988, 143(1), 65-70]. Since the traditional formulations are central to science, a brief analysis of some of these newer theories along traditional lines is attempted, based on well-attested axioms which have formed the basis of equilibrium thermodynamics. It is deduced that the Clausius analysis leading to the law of increasing entropy does not follow from the given axioms but it can be proved that for irreversible transitions, the total entropy change of the system and thermal reservoirs (the "Universe") is not negative, even for the case when the reservoirs are not at the same temperature as the system during heat transfer. On the basis of two new simple theorems and three corollaries derived for the correlation between irreversible and reversible pathways and the traditional axiomatics, it is shown that a sequence of reversible states can never be used to describe a corresponding sequence of irreversible states for at least closed systems, thereby restricting the principle of local equilibrium. It is further shown that some of the newer irreversible entropy forms given exhibit some paradoxical properties relative to the standard axiomatics. It is deduced that any reconciliation between the traditional approach and novel theories lie in creating a well defined set of axioms to which all theoretical developments should attempt to be based on unless proven not be useful, in which case there should be consensus in removing such axioms from theory. Clausius' theory of equivalent transformations do not contradict the traditional understanding of heat- work efficiency. It is concluded that the intuitively derived assumptions over the last two centuries seem to be reasonably well grounded, requiring perhaps some minor elaboration to the concepts of (i) system, (ii) the mechanism of heat transfer, and (iii) the environment, which would be expected to evolve with time in any case. If new generalizations at variance with Clausius' concepts are presented, then these ideas could be expected to require a different axiomatic basis than the one for equilibrium theory, and this difference must be stated at the outset of any new development. So far such empirically self-consistent axiomatic developments are not very much in evidence.

Application of a central composite design to evaluate the influence of colouring agents in lipstick formulation.

PubMed

Zibetti, F M; Cardoso, A C A; Desmarais, G C; de Almeida, K B; do Nascimento, L M; Rolim, L F; Rocha, M S; Duarte, N G D; Azevedo, P H R A; Araújo, J L; Mourão, S C; Falcão, D Q

2016-10-01

The aim of this study was to evaluate by central composite design the influence of colouring agents in lipstick colour, expressed by L*, a*, b* parameters (CIELab system) where L* indicates lightness, and a* and b* are the chromaticity coordinates. The a* indicates colour direction from red to green and b* from yellow to blue. Lipsticks were formulated as described by (Recent Adv. Prosp. Potent Med. Plants, 2009 and 39). The combined effect of three variables (dye, pigment and opacifier) was evaluated by different formulations in a central composite design. Colour parameters (L*, a*, b*) were analysed by reflectance spectrophotometry. Lipsticks were characterized by visual analyses and melting point. All formulations were integrate and homogeneous. The pigments and dye do not influence in colour transfer neither in melting point of lipsticks. On the other hand, results indicated that variables studied show influence only in parameter b*, whereas for L* and a* values there was no significant difference (P < 0.05). It was possible to verify that only the colour parameter b* was influenced by the variation in colouring agent's concentrations in lipstick formulation, leading to the production of the colour ranging between violet and light red. Such results are useful for developing new lipstick formulations to obtain the desired colour in the final product. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

A toy Penrose inequality and its proof

NASA Astrophysics Data System (ADS)

Bengtsson, Ingemar; Jakobsson, Emma

2016-12-01

We formulate and prove a toy version of the Penrose inequality. The formulation mimics the original Penrose inequality in which the scenario is the following: a shell of null dust collapses in Minkowski space and a marginally trapped surface forms on it. Through a series of arguments relying on established assumptions, an inequality relating the area of this surface to the total energy of the shell is formulated. Then a further reformulation turns the inequality into a statement relating the area and the outer null expansion of a class of surfaces in Minkowski space itself. The inequality has been proven to hold true in many special cases, but there is no proof in general. In the toy version here presented, an analogous inequality in (2 + 1)-dimensional anti-de Sitter space turns out to hold true.

Development of a Soluplus budesonide freeze-dried powder for nasal drug delivery.

PubMed

Pozzoli, Michele; Traini, Daniela; Young, Paul M; Sukkar, Maria B; Sonvico, Fabio

2017-09-01

The aim of this work was to develop an amorphous solid dispersions/solutions (ASD) of a poorly soluble drug, budesonide (BUD) with a novel polymer Soluplus ® (BASF, Germany) using a freeze-drying technique, in order to improve dissolution and absorption through the nasal route. The small volume of fluid present in the nasal cavity limits the absorption of a poorly soluble drug. Budesonide is a corticosteroid, practically insoluble and normally administered as a suspension-based nasal spray. The formulation was prepared through freeze-drying of polymer-drug solution. The formulation was assessed for its physicochemical (specific surface area, calorimetric analysis and X-ray powder diffraction), release properties and aerodynamic properties as well as transport in vitro using RPMI 2650 nasal cells, in order to elucidate the efficacy of the Soluplus-BUD formulation. The freeze-dried Soluplus-BUD formulation (LYO) showed a porous structure with a specific surface area of 1.4334 ± 0.0178 m 2 /g. The calorimetric analysis confirmed an interaction between BUD and Soluplus and X-ray powder diffraction the amorphous status of the drug. The freeze-dried formulation (LYO) showed faster release compared to both water-based suspension and dry powder commercial products. Furthermore, a LYO formulation, bulked with calcium carbonate (LYO-Ca), showed suitable aerodynamic characteristics for nasal drug delivery. The permeation across RPMI 2650 nasal cell model was higher compared to a commercial water-based BUD suspension. Soluplus has been shown to be a promising polymer for the formulation of BUD amorphous solid suspension/solution. This opens up opportunities to develop new formulations of poorly soluble drug for nasal delivery.

Preimplantation genetic diagnosis for gender selection in the United States

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

Colls, P.; Silver, L.; Olivera, G.

Preimplantation genetic diagnosis (PGD) of gender selection for non medical reasons has been considered an unethical procedure by several authors and agencies in the Western society on the basis of disrupting the sex ratio, being discriminatory againsts women and disposal of normal embryos of the non desired gender. In this study, the analysis of a large series of PGD procedures for gender selection from a wide geographical area in the United States, shows that in general there is no deviation in preference towards any specific gender except for a preference of males in some ethnic populations of Chinese, Indian andmore » Middle Eastern origin that represent a small percentage of the US population. In cases where only normal embryos of the non-desired gender are available, 45.5% of the couples elect to cancel the transfer, while 54.5% of them are open to have transferred embryos of the non-desired gender, this fact being strongly linked to cultural and ethnical background of the parents. In addition this study adds some evidence to the proposition that in couples with previous children of a given gender there is no biological predisposition towards producing embryos of that same gender. Based on these facts, it seems that objections to gender selection formulated by ethics committees and scientific societies are not well-founded.« less

Game theory based models to analyze water conflicts in the Middle Route of the South-to-North Water Transfer Project in China.

PubMed

Wei, Shouke; Yang, Hong; Abbaspour, Karim; Mousavi, Jamshid; Gnauck, Albrecht

2010-04-01

This study applied game theory based models to analyze and solve water conflicts concerning water allocation and nitrogen reduction in the Middle Route of the South-to-North Water Transfer Project in China. The game simulation comprised two levels, including one main game with five players and four sub-games with each containing three sub-players. We used statistical and econometric regression methods to formulate payoff functions of the players, economic valuation methods (EVMs) to transform non-monetary value into economic one, cost-benefit Analysis (CBA) to compare the game outcomes, and scenario analysis to investigate the future uncertainties. The validity of game simulation was evaluated by comparing predictions with observations. The main results proved that cooperation would make the players collectively better off, though some player would face losses. However, players were not willing to cooperate, which would result in a prisoners' dilemma. Scenarios simulation results displayed that players in water scare area could not solve its severe water deficit problem without cooperation with other players even under an optimistic scenario, while the uncertainty of cooperation would come from the main polluters. The results suggest a need to design a mechanism to reduce the risk of losses of those players by a side payment, which provides them with economic incentives to cooperate. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Modeling single event induced crosstalk in nanometer technologies

NASA Astrophysics Data System (ADS)

Boorla, Vijay K.

Radiation effects become more important in combinational logic circuits with newer technologies. When a high energetic particle strikes at the sensitive region within the combinational logic circuit a voltage pulse called Single Event Transient is created. Recently, researchers reported Single Event Crosstalk because of increasing coupling effects. In this work, the closed form expression for SE crosstalk noise is formulated for the first time. For all calculations, 4-pi model is used in this work. The crosstalk model uses a reduced transfer function between aggressor coupling node and victim node to reduce information loss. Aggressor coupling node waveform is obtained and then applied to transfer function between the coupling node and the victim output to obtain victim noise voltage. This work includes both effect of passive aggressor loading on victim and victim loading on aggressor by considering resistive shielding effect. Noise peak expressions derived in this work show very good results in comparison to HSPICE results. Results show that average error for noise peak is 3.794% while allowing for very fast analysis. Once the SE crosstalk noise is calculated, one can hire mitigation techniques such as driver sizing. A standard DTMOS technique along with sizing is proposed in this work to mitigate SE crosstalk. This combined approach can saves in some areas compared to driver sizing alone. Key Words: Crosstalk Noise, Closed Form Modeling, Standard DTMOS

Dissolution process analysis using model-free Noyes-Whitney integral equation.

PubMed

Hattori, Yusuke; Haruna, Yoshimasa; Otsuka, Makoto

2013-02-01

Drug dissolution process of solid dosages is theoretically described by Noyes-Whitney-Nernst equation. However, the analysis of the process is demonstrated assuming some models. Normally, the model-dependent methods are idealized and require some limitations. In this study, Noyes-Whitney integral equation was proposed and applied to represent the drug dissolution profiles of a solid formulation via the non-linear least squares (NLLS) method. The integral equation is a model-free formula involving the dissolution rate constant as a parameter. In the present study, several solid formulations were prepared via changing the blending time of magnesium stearate (MgSt) with theophylline monohydrate, α-lactose monohydrate, and crystalline cellulose. The formula could excellently represent the dissolution profile, and thereby the rate constant and specific surface area could be obtained by NLLS method. Since the long time blending coated the particle surface with MgSt, it was found that the water permeation was disturbed by its layer dissociating into disintegrant particles. In the end, the solid formulations were not disintegrated; however, the specific surface area gradually increased during the process of dissolution. The X-ray CT observation supported this result and demonstrated that the rough surface was dominant as compared to dissolution, and thus, specific surface area of the solid formulation gradually increased. Copyright © 2012 Elsevier B.V. All rights reserved.

Transfer of graphene onto Pt/Glass substrate for transparent and large area graphene film using low temperature water bath

NASA Astrophysics Data System (ADS)

Aziz, Tengku Norazman Tengku Abd; Rosli, Aimi Bazilah; Yusoff, Marmeezee Mohd; Herman, Sukreen Hana; Zulkifli, Zurita

2018-05-01

This paper demonstrates the transfer of graphene at low temperature using water bath. Graphene in water solution (highly opaque) was transferred onto Platinum/Glass (Pt/Glass) substrate and the technique involves no additional chemicals. We obtained high transparency and large area of graphene film that is free of contaminants. The transferred graphene is characterized using FESEM, Raman spectroscopy and I-V measurements. This transfer method enables us to transfer graphene onto ZnO thin film for memristive devices.

Development of shampoo, soap and ointment formulated by green synthesised silver nanoparticles functionalised with antimicrobial plants oils in veterinary dermatology: treatment and prevention strategies.

PubMed

Bansod, Sunita Dashrath; Bawaskar, Manisha Subrashrao; Gade, Aniket Krishnarao; Rai, Mahendra Kumar

2015-08-01

Many scientists have focused their research on the role of nanotechnology for the control of human pathogens, but there are also many topical pathogens present in animals, which infect animals and transfer to humans. Topical therapy is extremely important for the management of dermatological condition in animals. Therefore, the present study aims to evaluate the efficacy of biogenic silver nanoparticles (AgNPs) in combination with herbal oils against animal skin infections which may be responsible for causing infections in human beings. Here, the authors synthesised and characterised the AgNPs from Azadirachta indica. The oils were extracted from medicinal plants including Cymbopogon citratus, Cymbopogon martini, Eucalyptus globules, A. indica and Ocimum sanctum and the antifungal and antibacterial activity of plant oils along with AgNPs were evaluated. An excision wound model was used for the study of wound healing activity in rabbits. AgNPs functionalised oil has demonstrated remarkable antimicrobial activity against pathogens present on the skin of animals. The nano-functionalised antimicrobial oils were used in the formulation of shampoo, soap and ointment for veterinary dermatology. Antimicrobial products of plant origin with AgNPs are valuable, safe and have a specific role in controlling diseases. The authors believe that this approach will be a good alternative therapy to solve the continuous antibiotic resistance developed by many bacterial pathogens and will be utilised in various animal contacting areas in medicine.

Bhopal: lessons learned

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

Greenly, G.D. Jr.

1986-03-01

The risk assessment lesson learned from the Bhopal tragedy is both simple and complex. Practical planning for toxic material releases must start with an understanding of what the risks and possible consequences are. Additionally, plans must be formulated to ensure immediate decisive actions tailored to site specific scenarios, and the possible impacts projected on both the plant and surrounding communities. Most importantly, the planning process must include the communities that could be affected. Such planning will ultimately provide significant financial savings and provide for good public relations, and this makes good business sense in both developed and developing countries. Paraphrasingmore » the adage ''a penny saved is a penny earned,'' a penny spent on emergency preparedness is dollars earned through public awareness. The complex aspect of these simple concepts is overcoming human inertia, i.e., overcoming the ''it can't happen here'' syndrome in both government and private industry. A world center of excellence (ITRAC), acting as a center for education, research, and development in the area of emergency planning and response, will be the conduit for needed technology transfer to national centers of excellence in emergency planning and response. These national emergency planning and response centers (NARACS), managed by private industry for governments, will be catalysts to action in formulating effective plans involving potentially affected communities and plant management. The ITRAC/NARAC proposal is a simple concept involving complex ideas to solve the simple problem of being prepared for the Bhopal-like emergency which, as experience has demonstrated, will have complex consequences for the unprepared.« less

Movement of Diazinon Residues into Homes Following Applications of a Granular Formulation to Residential Lawns

EPA Science Inventory

A pilot study was conducted to examine the movement of diazinon following applications of a granular formulation to residential lawns. The objectives included examining the transport and fate of diazinon from an outdoor source to the indoor living areas of six homes, and estimati...

Effect of new auxin herbicide formulations on control of herbicide resistant weeds and on microbial activities in the rhizosphere

USDA-ARS?s Scientific Manuscript database

Widespread distribution of glyphosate-resistant weeds in soybean-growing areas across Mississippi has economically affected soybean planting and follow-up crop management operations. New multiple herbicide-resistant crop (including soybean) technologies with associated formulations will soon be comm...

A foam formulation of an entomopathogenic fungus for control of boring beetles in avocado orchards

USDA-ARS?s Scientific Manuscript database

A foam formulation of Beauveria bassiana was adapted to control boring beetles in avocado orchards. The two geographically independent avocado growing areas in the United States are threatened by emerging diseases vectored by boring beetles. In the California growing region, Fusarium dieback is vect...

Maternal immunization with respiratory syncytial virus fusion protein formulated with a novel combination adjuvant provides protection from RSV in newborn lambs.

PubMed

Garg, R; Latimer, L; Wang, Y; Simko, E; Gerdts, V; Potter, A; van Drunen Littel-van den Hurk, S

2016-01-04

Respiratory syncytial virus (RSV) is the causative agent of serious upper and lower respiratory tract infections in newborns and infants. Protection from RSV is crucial for neonates, and maternal immunization is one approach that holds promise for providing immediate protection to young infants against severe RSV infection. We previously reported efficacy of a subunit vaccine consisting of the fusion (F) protein formulated with a novel adjuvant (ΔF/TriAdj) in neonates. The goal of the current study was to evaluate the ΔF/TriAdj as a maternal vaccine. Pregnant ewes were vaccinated intramuscularly with ΔF/TriAdj or PBS six weeks prior to lambing, and re-vaccinated four weeks later, which resulted in transfer of maternal antibodies (MatAbs) to the newborn lambs through the colostrum. Significantly higher levels of RSV ΔF-specific serum IgG were detected in vaccinated pregnant ewes and their lambs when compared to control animals, which revealed that MatAbs were passively transferred to the offspring. All newborn lambs were challenged with RSV at three days of age. After RSV challenge, virus production and lung pathology were significantly lower in lambs that had received passively transferred antibodies than in control animals. These results indicate that maternal immunization with ΔF/TriAdj might be an alternative, safe and effective approach to provide protection against RSV in newborn and young infants. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Numerical Method for Incompressible Flow with Heat Transfer

NASA Technical Reports Server (NTRS)

Sa, Jong-Youb; Kwak, Dochan

1997-01-01

A numerical method for the convective heat transfer problem is developed for low speed flow at mild temperatures. A simplified energy equation is added to the incompressible Navier-Stokes formulation by using Boussinesq approximation to account for the buoyancy force. A pseudocompressibility method is used to solve the resulting set of equations for steady-state solutions in conjunction with an approximate factorization scheme. A Neumann-type pressure boundary condition is devised to account for the interaction between pressure and temperature terms, especially near a heated or cooled solid boundary. It is shown that the present method is capable of predicting the temperature field in an incompressible flow.

Correlation of heat transfer for the zero pressure gradient hypersonic laminar boundary layer for several gases

NASA Technical Reports Server (NTRS)

Cook, W. J.

1973-01-01

A theoretical study of heat transfer for zero pressure gradient hypersonic laminar boundary layers for various gases with particular application to the flows produced in an expansion tube facility was conducted. A correlation based on results obtained from solutions to the governing equations for five gases was formulated. Particular attention was directed toward the laminar boundary layer shock tube splitter plates in carbon dioxide flows generated by high speed shock waves. Computer analysis of the splitter plate boundary layer flow provided information that is useful in interpreting experimental data obtained in shock tube gas radiation studies.

Exosome-Mediated Genetic Information Transfer, a Missing Piece of Osteoblast-Osteoclast Communication Puzzle.

PubMed

Yin, Pengbin; Lv, Houchen; Li, Yi; Deng, Yuan; Zhang, Licheng; Tang, Peifu

2017-01-01

The skeletal system functions and maintains itself based on communication between cells of diverse origins, especially between osteoblasts (OBs) and osteoclasts (OCs), accounting for bone formation and resorption, respectively. Previously, protein-level information exchange has been the research focus, and this has been discussed in detail. The regulative effects of microRNAs (miRNAs) on OB and OC ignite the question as to whether genetic information could be transferred between bone cells. Exosomes, extracellular membrane vesicles 30-100 nm in diameter, have recently been demonstrated to transfer functional proteins, mRNAs, and miRNAs, and serve as mediators of intercellular communication. By reviewing the distinguishing features of exosomes, a hypothesis was formulated and evaluated in this article that exosome-mediated genetic information transfer may represent a novel strategy for OB-OC communication. The exosomes may coordinately regulate these two cells under certain physiological conditions by transferring genetic information. Further research in exosome-shuttered miRNAs in OB-OC communication may add a missing piece to the bone cells communication "puzzle."

Application of different variants of the BEM in numerical modeling of bioheat transfer problems.

PubMed

Majchrzak, Ewa

2013-09-01

Heat transfer processes proceeding in the living organisms are described by the different mathematical models. In particular, the typical continuous model of bioheat transfer bases on the most popular Pennes equation, but the Cattaneo-Vernotte equation and the dual phase lag equation are also used. It should be pointed out that in parallel are also examined the vascular models, and then for the large blood vessels and tissue domain the energy equations are formulated separately. In the paper the different variants of the boundary element method as a tool of numerical solution of bioheat transfer problems are discussed. For the steady state problems and the vascular models the classical BEM algorithm and also the multiple reciprocity BEM are presented. For the transient problems connected with the heating of tissue, the various tissue models are considered for which the 1st scheme of the BEM, the BEM using discretization in time and the general BEM are applied. Examples of computations illustrate the possibilities of practical applications of boundary element method in the scope of bioheat transfer problems.

A generalized volumetric dispersion model for a class of two-phase separation/reaction: finite difference solutions

NASA Astrophysics Data System (ADS)

Siripatana, Chairat; Thongpan, Hathaikarn; Promraksa, Arwut

2017-03-01

This article explores a volumetric approach in formulating differential equations for a class of engineering flow problems involving component transfer within or between two phases. In contrast to conventional formulation which is based on linear velocities, this work proposed a slightly different approach based on volumetric flow-rate which is essentially constant in many industrial processes. In effect, many multi-dimensional flow problems found industrially can be simplified into multi-component or multi-phase but one-dimensional flow problems. The formulation is largely generic, covering counter-current, concurrent or batch, fixed and fluidized bed arrangement. It was also intended to use for start-up, shut-down, control and steady state simulation. Since many realistic and industrial operation are dynamic with variable velocity and porosity in relation to position, analytical solutions are rare and limited to only very simple cases. Thus we also provide a numerical solution using Crank-Nicolson finite difference scheme. This solution is inherently stable as tested against a few cases published in the literature. However, it is anticipated that, for unconfined flow or non-constant flow-rate, traditional formulation should be applied.

40 CFR 35.6120 - Notification of the out-of-State or out-of-an-Indian-Tribal-area-of-Indian-country transfer of...

Code of Federal Regulations, 2012 CFR

2012-07-01

...-of-an-Indian-Tribal-area-of-Indian-country transfer of CERCLA waste. 35.6120 Section 35.6120...-of-Indian-country transfer of CERCLA waste. (a) The recipient must provide written notification of off-site shipments of CERCLA waste from a site to an out-of-State or out-of-an-Indian-Tribal-area-of...

40 CFR 35.6120 - Notification of the out-of-State or out-of-an-Indian-Tribal-area-of-Indian-country transfer of...

Code of Federal Regulations, 2014 CFR

2014-07-01

...-of-an-Indian-Tribal-area-of-Indian-country transfer of CERCLA waste. 35.6120 Section 35.6120...-of-Indian-country transfer of CERCLA waste. (a) The recipient must provide written notification of off-site shipments of CERCLA waste from a site to an out-of-State or out-of-an-Indian-Tribal-area-of...

Beyond the standard two-film theory: Computational fluid dynamics simulations for carbon dioxide capture in a wetted wall column

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

Wang, Chao; Xu, Zhijie; Lai, Canhai

The standard two-film theory (STFT) is a diffusion-based mechanism that can be used to describe gas mass transfer across liquid film. Fundamental assumptions of the STFT impose serious limitations on its ability to predict mass transfer coefficients. To better understand gas absorption across liquid film in practical situations, a multiphase computational fluid dynamics (CFD) model fully equipped with mass transport and chemistry capabilities has been developed for solvent-based carbon dioxide (CO 2) capture to predict the CO 2 mass transfer coefficient in a wetted wall column. The hydrodynamics is modeled using a volume of fluid method, and the diffusive andmore » reactive mass transfer between the two phases is modeled by adopting a one-fluid formulation. We demonstrate that the proposed CFD model can naturally account for the influence of many important factors on the overall mass transfer that cannot be quantitatively explained by the STFT, such as the local variation in fluid velocities and properties, flow instabilities, and complex geometries. The CFD model also can predict the local mass transfer coefficient variation along the column height, which the STFT typically does not consider.« less

Beyond the standard two-film theory: Computational fluid dynamics simulations for carbon dioxide capture in a wetted wall column

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

Wang, Chao; Xu, Zhijie; Lai, Canhai

The standard two-film theory (STFT) is a diffusion-based mechanism that can be used to describe gas mass transfer across liquid film. Fundamental assumptions of the STFT impose serious limitations on its ability to predict mass transfer coefficients. To better understand gas absorption across liquid film in practical situations, a multiphase computational fluid dynamics (CFD) model fully equipped with mass transport and chemistry capabilities has been developed for solvent-based carbon dioxide (CO2) capture to predict the CO2 mass transfer coefficient in a wetted wall column. The hydrodynamics is modeled using a volume of fluid method, and the diffusive and reactive massmore » transfer between the two phases is modeled by adopting a one-fluid formulation. We demonstrate that the proposed CFD model can naturally account for the influence of many important factors on the overall mass transfer that cannot be quantitatively explained by the STFT, such as the local variation in fluid velocities and properties, flow instabilities, and complex geometries. The CFD model also can predict the local mass transfer coefficient variation along the column height, which the STFT typically does not consider.« less

The design of transfer trajectory for Ivar asteroid exploration mission

NASA Astrophysics Data System (ADS)

Qiao, Dong; Cui, Hutao; Cui, Pingyuan

2009-12-01

An impending demand for exploring the small bodies, such as the comets and the asteroids, envisioned the Chinese Deep Space exploration mission to the Near Earth asteroid Ivar. A design and optimal method of transfer trajectory for asteroid Ivar is discussed in this paper. The transfer trajectory for rendezvous with asteroid Ivar is designed by means of Earth gravity assist with deep space maneuver (Delta-VEGA) technology. A Delta-VEGA transfer trajectory is realized by several trajectory segments, which connect the deep space maneuver and swingby point. Each trajectory segment is found by solving Lambert problem. Through adjusting deep maneuver and arrival time, the match condition of swingby is satisfied. To reduce the total mission velocity increments further, a procedure is developed which minimizes total velocity increments for this scheme of transfer trajectory for asteroid Ivar. The trajectory optimization problem is solved with a quasi-Newton algorithm utilizing analytic first derivatives, which are derived from the transversality conditions associated with the optimization formulation and primer vector theory. The simulation results show the scheme for transfer trajectory causes C3 and total velocity increments decrease of 48.80% and 13.20%, respectively.

Numerical analysis of fractional MHD Maxwell fluid with the effects of convection heat transfer condition and viscous dissipation

NASA Astrophysics Data System (ADS)

Bai, Yu; Jiang, Yuehua; Liu, Fawang; Zhang, Yan

2017-12-01

This paper investigates the incompressible fractional MHD Maxwell fluid due to a power function accelerating plate with the first order slip, and the numerical analysis on the flow and heat transfer of fractional Maxwell fluid has been done. Moreover the deformation motion of fluid micelle is simply analyzed. Nonlinear velocity equation are formulated with multi-term time fractional derivatives in the boundary layer governing equations, and convective heat transfer boundary condition and viscous dissipation are both taken into consideration. A newly finite difference scheme with L1-algorithm of governing equations are constructed, whose convergence is confirmed by the comparison with analytical solution. Numerical solutions for velocity and temperature show the effects of pertinent parameters on flow and heat transfer of fractional Maxwell fluid. It reveals that the fractional derivative weakens the effects of motion and heat conduction. The larger the Nusselt number is, the greater the heat transfer capacity of fluid becomes, and the temperature gradient at the wall becomes more significantly. The lower Reynolds number enhances the viscosity of the fluid because it is the ratio of the viscous force and the inertia force, which resists the flow and heat transfer.

Beyond the standard two-film theory: Computational fluid dynamics simulations for carbon dioxide capture in a wetted wall column

DOE PAGES

Wang, Chao; Xu, Zhijie; Lai, Canhai; ...

2018-03-27

The standard two-film theory (STFT) is a diffusion-based mechanism that can be used to describe gas mass transfer across liquid film. Fundamental assumptions of the STFT impose serious limitations on its ability to predict mass transfer coefficients. To better understand gas absorption across liquid film in practical situations, a multiphase computational fluid dynamics (CFD) model fully equipped with mass transport and chemistry capabilities has been developed for solvent-based carbon dioxide (CO 2) capture to predict the CO 2 mass transfer coefficient in a wetted wall column. The hydrodynamics is modeled using a volume of fluid method, and the diffusive andmore » reactive mass transfer between the two phases is modeled by adopting a one-fluid formulation. We demonstrate that the proposed CFD model can naturally account for the influence of many important factors on the overall mass transfer that cannot be quantitatively explained by the STFT, such as the local variation in fluid velocities and properties, flow instabilities, and complex geometries. The CFD model also can predict the local mass transfer coefficient variation along the column height, which the STFT typically does not consider.« less

Baseline levels and trophic transfer of persistent organic pollutants in sediments and biota from the Congo River Basin (DR Congo).

PubMed

Verhaert, Vera; Covaci, Adrian; Bouillon, Steven; Abrantes, Katya; Musibono, Dieudonné; Bervoets, Lieven; Verheyen, Erik; Blust, Ronny

2013-09-01

The present study aimed to evaluate the occurrence of persistent organic pollutants (POPs: (PCBs, PBDEs, DDTs, HCHs, CHLs and HCB) in sediments and biota from the middle Congo River Basin (CRB) and to investigate their trophic transfer through the aquatic food web using nitrogen stable isotope ratios. To our knowledge, no data on levels of POPs in sediment and biota from the CRB are present in the literature, and studies on trophic transfer and biomagnification profiles of POPs using δ(15)N are scarce in tropical regions. POP levels in the sediment and biota were low, with exception of total PCB levels found in fish from the Itimbiri River (1.4 to 44ng/g ww). Compared to concentrations found in fish from pristine to relatively industrial developed areas, the ∑PCB levels in fish from the Itimbiri were high, indicating the presence of a local PCB contamination source in this catchment. Based on minimum risk level criteria formulated by ATSDR, the consumption of PCB contaminated fish from the Itimbiri river poses a potential risk for humans. The POP levels in biota were not significantly related to the POP levels in sediments, and the BSAF concept (Biota-Sediment Accumulation Factor) was found to be a poor predictor of the bioavailability and bioaccumulation of environmental pollutants in the present study. With increasing trophic levels, a significant increase in PCB 95, 101, 110, 138, 146, 149, 153, 174, 180 & 187 and p,p'-DDT in Itimbiri and BDE 47 & 99 in Itimbiri, Aruwimi & Lomami river basins was observed. Trophic magnification factors were higher than 1, indicating that biomagnification occurs through the tropical food web. Copyright © 2013 Elsevier Ltd. All rights reserved.

Information transfer across the scales of climate data variability

NASA Astrophysics Data System (ADS)

Palus, Milan; Jajcay, Nikola; Hartman, David; Hlinka, Jaroslav

2015-04-01

Multitude of scales characteristic of the climate system variability requires innovative approaches in analysis of instrumental time series. We present a methodology which starts with a wavelet decomposition of a multi-scale signal into quasi-oscillatory modes of a limited band-with, described using their instantaneous phases and amplitudes. Then their statistical associations are tested in order to search for interactions across time scales. In particular, an information-theoretic formulation of the generalized, nonlinear Granger causality is applied together with surrogate data testing methods [1]. The method [2] uncovers causal influence (in the Granger sense) and information transfer from large-scale modes of climate variability with characteristic time scales from years to almost a decade to regional temperature variability on short time scales. In analyses of daily mean surface air temperature from various European locations an information transfer from larger to smaller scales has been observed as the influence of the phase of slow oscillatory phenomena with periods around 7-8 years on amplitudes of the variability characterized by smaller temporal scales from a few months to annual and quasi-biennial scales [3]. In sea surface temperature data from the tropical Pacific area an influence of quasi-oscillatory phenomena with periods around 4-6 years on the variability on and near the annual scale has been observed. This study is supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Program KONTAKT II, Project No. LH14001. [1] M. Palus, M. Vejmelka, Phys. Rev. E 75, 056211 (2007) [2] M. Palus, Entropy 16(10), 5263-5289 (2014) [3] M. Palus, Phys. Rev. Lett. 112, 078702 (2014)

FAST TRACK COMMUNICATION Heat transfer between graphene and amorphous SiO2

NASA Astrophysics Data System (ADS)

Persson, B. N. J.; Ueba, H.

2010-11-01

We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer results from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.

Application of FTIR microscopy in the study of pharmaceutical packaging materials and formulations

NASA Astrophysics Data System (ADS)

Hu, John J.; Johnson, James B.

1992-08-01

Fourier transform infrared microscopy offers many unique advantages in studying pharmaceutical packaging materials and formulations because of its sensitivity and variety of measurement modes with precise control of the area to the analyzed. This report discusses the application of FTIR microscopy in studying commonly encountered pharmaceutical packaging components such as multi-layer laminate films, disposable syringes and rubber stoppers. The use of the instrument to study pharmaceutical formulation parameters such as polymorphism and component identification is also presented.

Cable Connected Spinning Spacecraft, 1. the Canonical Equations, 2. Urban Mass Transportation, 3

NASA Technical Reports Server (NTRS)

Sitchin, A.

1972-01-01

Work on the dynamics of cable-connected spinning spacecraft was completed by formulating the equations of motion by both the canonical equations and Lagrange's equations and programming them for numerical solution on a digital computer. These energy-based formulations will permit future addition of the effect of cable mass. Comparative runs indicate that the canonical formulation requires less computer time. Available literature on urban mass transportation was surveyed. Areas of the private rapid transit concept of urban transportation are also studied.

Randomized clinical efficacy of superficial peeling with 85% lactic acid versus 70% glycolic acid.

PubMed

Prestes, Paula Souza; Oliveira, Márcia Motta Maia de; Leonardi, Gislaine Ricci

2013-01-01

Peeling is a procedure which aims to accelerate the process of skin exfoliation. Development of formulations containing lactic acid at 85% or glycolic acid at 70% and the evaluation of these formulations on clinical efficacy in reduction of fine wrinkles. Preliminary stability tests were carried out and an in vivo study was performed with three groups with 9 representatives each. One was the control group, which used only sunscreen; another one used lactic acid+sunscreen, and the last group used acid glycolic+sunscreen. Clinical efficacy was assessed with a CCD color microscope, through the digitization of images before and after treatment. The applications were carried out by a dermatologist, once a mont h every 30 days, during 3 months. The area with wrinkles was calculated by planimetry point counting, in accordance with Mandarin-de-Lacerda. The formulations were stable in the visual and Ph evaluation. There was no improvement in the control group; for lactic acid, there was significant improvement after the second peeling application on the outer lateral area of the right eye and after the third application on the outer lateral area of the left eye. For the glycolic acid group, there was significant improvement in the outer lateral area of the left eye after the first application, and of the right eye region, after three applications. The formulations used must be kept under refrigeration and should be manipulated every 30 days. Both peelings were effective in reducing fine wrinkles of the outer lateral eye area after three applications (p ≤ 0.05%). It was observed that peeling efficacy in the external-lateral region of one eye might be different compared with that in skin of the external-lateral region of the other eye, relative to the speed of skin improvement.

140. VIEW OF CHECKOUT AREA (117), LSB (BLDG. 770), FROM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

140. VIEW OF CHECKOUT AREA (117), LSB (BLDG. 770), FROM AGENA TRANSFER AREA SHELTER (117A). NITROGEN TEST PANEL ON EAST WALL OF AGENA TRANSFER AREA SHELTER (117A). - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Instrumentation development for study of Reynolds Analogy in reacting flows

NASA Technical Reports Server (NTRS)

Deturris, Dianne J.

1995-01-01

Boundary layers in supersonic reacting flows are not well understood. Recently a technique has been developed which makes more extensive surface measurements practical, increasing the capability to understand the turbulent boundary layer. A significant advance in this understanding would be the formulation of an analytic relation between the transfer of momentum and the transfer of heat for this flow, similar to the Reynolds Analogy that exists for laminar flow. A gauge has been designed and built which allows a thorough experimental investigation of the relative effects of heat transfer and skin friction in the presence of combustion. Direct concurrent measurements made at the same location, combined with local flow conditions, enable a quantitative analysis to obtain a relation between the surface drag and wall heating, as well as identifying possible ways of reducing both.

A Numerical-Analytical Approach Based on Canonical Transformations for Computing Optimal Low-Thrust Transfers

NASA Astrophysics Data System (ADS)

da Silva Fernandes, S.; das Chagas Carvalho, F.; Bateli Romão, J. V.

2018-04-01

A numerical-analytical procedure based on infinitesimal canonical transformations is developed for computing optimal time-fixed low-thrust limited power transfers (no rendezvous) between coplanar orbits with small eccentricities in an inverse-square force field. The optimization problem is formulated as a Mayer problem with a set of non-singular orbital elements as state variables. Second order terms in eccentricity are considered in the development of the maximum Hamiltonian describing the optimal trajectories. The two-point boundary value problem of going from an initial orbit to a final orbit is solved by means of a two-stage Newton-Raphson algorithm which uses an infinitesimal canonical transformation. Numerical results are presented for some transfers between circular orbits with moderate radius ratio, including a preliminary analysis of Earth-Mars and Earth-Venus missions.

LSI arrays for space stations

NASA Technical Reports Server (NTRS)

Gassaway, J. D.

1976-01-01

Two approaches have been taken to study CCD's and some of their fundamental limitations. First a numerical analysis approach has been developed to solve the coupled transport and Poisson's equation for a thorough analysis of charge transfer in a CCD structure. The approach is formulated by treating the minority carriers as a surface distribution at the Si-SiO2 interface and setting up coupled difference equations for the charge and the potential. The SOR method is proposed for solving the two dimensional Poisson's equation for the potential. Methods are suggested for handling the discontinuities to improve convergence. Second, CCD shift registers were fabricated with parameters which should allow complete charge transfer independent of the transfer electrode gap width. A test instrument was designed and constructed which can be used to test this, or any similar, three phase CCD shift register.

AC losses in horizontally parallel HTS tapes for possible wireless power transfer applications

NASA Astrophysics Data System (ADS)

Shen, Boyang; Geng, Jianzhao; Zhang, Xiuchang; Fu, Lin; Li, Chao; Zhang, Heng; Dong, Qihuan; Ma, Jun; Gawith, James; Coombs, T. A.

2017-12-01

This paper presents the concept of using horizontally parallel HTS tapes with AC loss study, and the investigation on possible wireless power transfer (WPT) applications. An example of three parallel HTS tapes was proposed, whose AC loss study was carried out both from experiment using electrical method; and simulation using 2D H-formulation on the FEM platform of COMSOL Multiphysics. The electromagnetic induction around the three parallel tapes was monitored using COMSOL simulation. The electromagnetic induction and AC losses generated by a conventional three turn coil was simulated as well, and then compared to the case of three parallel tapes with the same AC transport current. The analysis demonstrates that HTS parallel tapes could be potentially used into wireless power transfer systems, which could have lower total AC losses than conventional HTS coils.

Aerodynamic heating rate distributions induced by trailing edge controls on hypersonic aircraft configurations at Mach 8

NASA Technical Reports Server (NTRS)

Kaufman, L. G., II; Johnson, C. B.

1984-01-01

Aerodynamic surface heating rate distributions in three dimensional shock wave boundary layer interaction flow regions are presented for a generic set of model configurations representative of the aft portion of hypersonic aircraft. Heat transfer data were obtained using the phase change coating technique (paint) and, at particular spanwise and streamwise stations for sample cases, by the thin wall transient temperature technique (thermocouples). Surface oil flow patterns are also shown. The good accuracy of the detailed heat transfer data, as attested in part by their repeatability, is attributable partially to the comparatively high temperature potential of the NASA-Langley Mach 8 Variable Density Tunnel. The data are well suited to help guide heating analyses of Mach 8 aircraft, and should be considered in formulating improvements to empiric analytic methods for calculating heat transfer rate coefficient distributions.

Quantum kinetic expansion in the spin-boson model: Matrix formulation and system-bath factorized initial state.

PubMed

Gong, Zhihao; Tang, Zhoufei; Wang, Haobin; Wu, Jianlan

2017-12-28

Within the framework of the hierarchy equation of motion (HEOM), the quantum kinetic expansion (QKE) method of the spin-boson model is reformulated in the matrix representation. The equivalence between the two formulations (HEOM matrices and quantum operators) is numerically verified from the calculation of the time-integrated QKE rates. The matrix formulation of the QKE is extended to the system-bath factorized initial state. Following a one-to-one mapping between HEOM matrices and quantum operators, a quantum kinetic equation is rederived. The rate kernel is modified by an extra term following a systematic expansion over the site-site coupling. This modified QKE is numerically tested for its reliability by calculating the time-integrated rate and non-Markovian population kinetics. For an intermediate-to-strong dissipation strength and a large site-site coupling, the population transfer is found to be significantly different when the initial condition is changed from the local equilibrium to system-bath factorized state.

Support Vector Data Descriptions and k-Means Clustering: One Class?

PubMed

Gornitz, Nico; Lima, Luiz Alberto; Muller, Klaus-Robert; Kloft, Marius; Nakajima, Shinichi

2017-09-27

We present ClusterSVDD, a methodology that unifies support vector data descriptions (SVDDs) and k-means clustering into a single formulation. This allows both methods to benefit from one another, i.e., by adding flexibility using multiple spheres for SVDDs and increasing anomaly resistance and flexibility through kernels to k-means. In particular, our approach leads to a new interpretation of k-means as a regularized mode seeking algorithm. The unifying formulation further allows for deriving new algorithms by transferring knowledge from one-class learning settings to clustering settings and vice versa. As a showcase, we derive a clustering method for structured data based on a one-class learning scenario. Additionally, our formulation can be solved via a particularly simple optimization scheme. We evaluate our approach empirically to highlight some of the proposed benefits on artificially generated data, as well as on real-world problems, and provide a Python software package comprising various implementations of primal and dual SVDD as well as our proposed ClusterSVDD.

Cationic lipids bearing succinic-based, acyclic and macrocyclic hydrophobic domains: Synthetic studies and in vitro gene transfer.

PubMed

Jubeli, Emile; Maginty, Amanda B; Khalique, Nada Abdul; Raju, Liji; Nicholson, David G; Larsen, Helge; Pungente, Michael D; Goldring, William P D

2017-01-05

In this communication we describe the construction of four succinic-based cationic lipids, their formulation with plasmid DNA (pDNA), and an evaluation of their in vitro gene delivery into Chinese hamster ovarian (CHO-K1) cells. The cationic lipids employed in this work possess either a dimethylamine or trimethylamine headgroup, and a macrocyclic or an acyclic hydrophobic domain composed of, or derived from two 16-atom, succinic-based acyl chains. The synthesized lipids and a co-lipid of neutral charge, either cholesterol or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), were formulated in an overall 3:2 cationic-to-neutral lipid molar ratio, then complexed with plasmid DNA (pDNA). The relative transfection performance was evaluated via a comparison between matched versus mismatched formulations defined by the rigidity relationship between the lipids employed. Gel electrophoresis was used to characterize the binding of the lipid formulations with plasmid DNA and the relative degree of plasmid degradation using a DNase I degradation assay. Small angle X-ray diffraction (SAXD) was employed to characterize the packing morphology of the lipid-DNA complexes. In general, the succinic unit embedded within the hydrophobic domain of the cationic lipids was found to improve lipid hydration. The transfection assays revealed a general trend in which mismatched formulations that employed a rigid lipid combined with a non-rigid (or flexible) lipid, outperformed the matched formulations. The results from this work suggest that the design of the cationic lipid structure and the composition of the lipoplex formulation play key roles in governing the transfection performance of nonviral gene delivery agents. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Approximate Solution Methods for Spectral Radiative Transfer in High Refractive Index Layers

NASA Technical Reports Server (NTRS)

Siegel, R.; Spuckler, C. M.

1994-01-01

Some ceramic materials for high temperature applications are partially transparent for radiative transfer. The refractive indices of these materials can be substantially greater than one which influences internal radiative emission and reflections. Heat transfer behavior of single and laminated layers has been obtained in the literature by numerical solutions of the radiative transfer equations coupled with heat conduction and heating at the boundaries by convection and radiation. Two-flux and diffusion methods are investigated here to obtain approximate solutions using a simpler formulation than required for exact numerical solutions. Isotropic scattering is included. The two-flux method for a single layer yields excellent results for gray and two band spectral calculations. The diffusion method yields a good approximation for spectral behavior in laminated multiple layers if the overall optical thickness is larger than about ten. A hybrid spectral model is developed using the two-flux method in the optically thin bands, and radiative diffusion in bands that are optically thick.

A direct approach to the design of linear multivariable systems

NASA Technical Reports Server (NTRS)

Agrawal, B. L.

1974-01-01

Design of multivariable systems is considered and design procedures are formulated in the light of the most recent work on model matching. The word model matching is used exclusively to mean matching the input-output behavior of two systems. The term is used in the frequency domain to indicate the comparison of two transfer matrices containing transfer functions as elements. Design methods where non-interaction is not used as a criteria were studied. Two design methods are considered. The first method of design is based solely upon the specification of generalized error coefficients for each individual transfer function of the overall system transfer matrix. The second design method is called the pole fixing method because all the system poles are fixed at preassigned positions. The zeros of terms either above or below the diagonal are partially fixed via steady state error coefficients. The advantages and disadvantages of each method are discussed and an example is worked to demonstrate their uses. The special cases of triangular decoupling and minimum constraints are discussed.

Heterogeneous nanofluids: natural convection heat transfer enhancement

NASA Astrophysics Data System (ADS)

Oueslati, Fakhreddine Segni; Bennacer, Rachid

2011-12-01

Convective heat transfer using different nanofluid types is investigated. The domain is differentially heated and nanofluids are treated as heterogeneous mixtures with weak solutal diffusivity and possible Soret separation. Owing to the pronounced Soret effect of these materials in combination with a considerable solutal expansion, the resulting solutal buoyancy forces could be significant and interact with the initial thermal convection. A modified formulation taking into account the thermal conductivity, viscosity versus nanofluids type and concentration and the spatial heterogeneous concentration induced by the Soret effect is presented. The obtained results, by solving numerically the full governing equations, are found to be in good agreement with the developed solution based on the scale analysis approach. The resulting convective flows are found to be dependent on the local particle concentration φ and the corresponding solutal to thermal buoyancy ratio N. The induced nanofluid heterogeneity showed a significant heat transfer modification. The heat transfer in natural convection increases with nanoparticle concentration but remains less than the enhancement previously underlined in forced convection case.

Infrared and visible image fusion based on total variation and augmented Lagrangian.

PubMed

Guo, Hanqi; Ma, Yong; Mei, Xiaoguang; Ma, Jiayi

2017-11-01

This paper proposes a new algorithm for infrared and visible image fusion based on gradient transfer that achieves fusion by preserving the intensity of the infrared image and then transferring gradients in the corresponding visible one to the result. The gradient transfer suffers from the problems of low dynamic range and detail loss because it ignores the intensity from the visible image. The new algorithm solves these problems by providing additive intensity from the visible image to balance the intensity between the infrared image and the visible one. It formulates the fusion task as an l 1 -l 1 -TV minimization problem and then employs variable splitting and augmented Lagrangian to convert the unconstrained problem to a constrained one that can be solved in the framework of alternating the multiplier direction method. Experiments demonstrate that the new algorithm achieves better fusion results with a high computation efficiency in both qualitative and quantitative tests than gradient transfer and most state-of-the-art methods.

Physiology and culture of the human blastocyst.

PubMed

Gardner, David K; Lane, Michelle; Schoolcraft, William B

2002-01-01

The human embryo undergoes many changes in physiology during the first 4 days of life as it develops and differentiates from a fertilized oocyte to the blastocyst stage. Concomitantly, the embryo is exposed to gradients of nutrients within the female reproductive tract and exhibits changes in its own nutrient requirements and utilization. Determining the nature of such nutrient gradients in the female tract and the changing requirements of the embryo has facilitated the formulation of stage-specific culture media designed to support embryo development throughout the preimplantation period. Resultant implantation rates attained with the culture and transfer of human blastocysts are higher than those associated with the transfer of cleavage stage embryos to the uterus. Such increases in implantation rates have facilitated the establishment of high pregnancy rates while reducing the number of embryos transferred. With the introduction of new scoring systems for the blastocyst and the non-invasive assessment of metabolic activity of individual embryos, it should be possible to move to single blastocyst transfer for the majority of patients.

Heterogeneous nanofluids: natural convection heat transfer enhancement

PubMed Central

2011-01-01

Convective heat transfer using different nanofluid types is investigated. The domain is differentially heated and nanofluids are treated as heterogeneous mixtures with weak solutal diffusivity and possible Soret separation. Owing to the pronounced Soret effect of these materials in combination with a considerable solutal expansion, the resulting solutal buoyancy forces could be significant and interact with the initial thermal convection. A modified formulation taking into account the thermal conductivity, viscosity versus nanofluids type and concentration and the spatial heterogeneous concentration induced by the Soret effect is presented. The obtained results, by solving numerically the full governing equations, are found to be in good agreement with the developed solution based on the scale analysis approach. The resulting convective flows are found to be dependent on the local particle concentration φ and the corresponding solutal to thermal buoyancy ratio N. The induced nanofluid heterogeneity showed a significant heat transfer modification. The heat transfer in natural convection increases with nanoparticle concentration but remains less than the enhancement previously underlined in forced convection case. PMID:21711755

Ultrafast energy transfer with competing channels: Non-equilibrium Förster and Modified Redfield theories

NASA Astrophysics Data System (ADS)

Seibt, Joachim; Mančal, Tomáš

2017-05-01

We derive equations of motion for the reduced density matrix of a molecular system which undergoes energy transfer dynamics competing with fast internal conversion channels. Environmental degrees of freedom of such a system have no time to relax to quasi-equilibrium in the electronic excited state of the donor molecule, and thus the conditions of validity of Förster and Modified Redfield theories in their standard formulations do not apply. We derive non-equilibrium versions of the two well-known rate theories and apply them to the case of carotenoid-chlorophyll energy transfer. Although our reduced density matrix approach does not account for the formation of vibronic excitons, it still confirms the important role of the donor ground-state vibrational states in establishing the resonance energy transfer conditions. We show that it is essential to work with a theory valid in a strong system-bath interaction regime to obtain correct dependence of the rates on donor-acceptor energy gap.

Numerical study of MHD nanofluid flow and heat transfer past a bidirectional exponentially stretching sheet

NASA Astrophysics Data System (ADS)

Ahmad, Rida; Mustafa, M.; Hayat, T.; Alsaedi, A.

2016-06-01

Recent advancements in nanotechnology have led to the discovery of new generation coolants known as nanofluids. Nanofluids possess novel and unique characteristics which are fruitful in numerous cooling applications. Current work is undertaken to address the heat transfer in MHD three-dimensional flow of magnetic nanofluid (ferrofluid) over a bidirectional exponentially stretching sheet. The base fluid is considered as water which consists of magnetite-Fe3O4 nanoparticles. Exponentially varying surface temperature distribution is accounted. Problem formulation is presented through the Maxwell models for effective electrical conductivity and effective thermal conductivity of nanofluid. Similarity transformations give rise to a coupled non-linear differential system which is solved numerically. Appreciable growth in the convective heat transfer coefficient is observed when nanoparticle volume fraction is augmented. Temperature exponent parameter serves to enhance the heat transfer from the surface. Moreover the skin friction coefficient is directly proportional to both magnetic field strength and nanoparticle volume fraction.

Time-fixed rendezvous by impulse factoring with an intermediate timing constraint. [for transfer orbits

NASA Technical Reports Server (NTRS)

Green, R. N.; Kibler, J. F.; Young, G. R.

1974-01-01

A method is presented for factoring a two-impulse orbital transfer into a three- or four-impulse transfer which solves the rendezvous problem and satisfies an intermediate timing constraint. Both the time of rendezvous and the intermediate time of a alinement are formulated as any element of a finite sequence of times. These times are integer multiples of a constant plus an additive constant. The rendezvous condition is an equality constraint, whereas the intermediate alinement is an inequality constraint. The two timing constraints are satisfied by factoring the impulses into collinear parts that vectorially sum to the original impulse and by varying the resultant period differences and the number of revolutions in each orbit. Five different types of solutions arise by considering factoring either or both of the two impulses into two or three parts with a limit for four total impulses. The impulse-factoring technique may be applied to any two-impulse transfer which has distinct orbital periods.

Advanced k-epsilon modeling of heat transfer

NASA Technical Reports Server (NTRS)

Kwon, Okey; Ames, Forrest E.

1995-01-01

This report describes two approaches to low Reynolds-number k-epsilon turbulence modeling which formulate the eddy viscosity on the wall-normal component of turbulence and a length scale. The wall-normal component of turbulence is computed via integration of the energy spectrum based on the local dissipation rate and is bounded by the isotropic condition. The models account for the anisotropy of the dissipation and the reduced mixing length due to the high strain rates present in the near-wall region. The turbulent kinetic energy and its dissipation rate were computed from the k and epsilon transport equations of Durbin. The models were tested for a wide range of turbulent flows and proved to be superior to other k-epsilon models, especially for nonequilibrium anisotropic flows. For the prediction of airfoil heat transfer, the models included a set of empirical correlations for predicting laminar-turbulent transition and laminar heat transfer augmentation due to the presence of freestream turbulence. The predictions of surface heat transfer were generally satisfactory.

Ion-specific weak adsorption of salts and water/octanol transfer free energy of a model amphiphilic hexapeptide.

PubMed

Déjugnat, Christophe; Dufrêche, Jean-François; Zemb, Thomas

2011-04-21

An amphiphilic hexapeptide has been used as a model to quantify how specific ion effects induced by addition of four salts tune the hydrophilic/hydrophobic balance and induce temperature-dependant coacervate formation from aqueous solution. The hexapeptide chosen is present as a dimer with low transfer energy from water to octanol. Taking sodium chloride as the reference state in the Hofmeister scale, we identify water activity effects and therefore measure the free energy of transfer from water to octanol and separately the free energy associated to the adsorption of chaotropic ions or the desorption of kosmotropic ions for the same amphiphilic peptide. These effects have the same order of magnitude: therefore, both energies of solvation as well as transfer into octanol strongly depend on the nature of the electrolytes used to formulate any buffer. Model peptides could be used on separation processes based on criteria linked to "Hofmeister" but different from volume and valency.

Mass-transfer limitations for immobilized enzyme-catalyzed kinetic resolution of racemate in a fixed-bed reactor.

PubMed

Xiu, G H; Jiang, L; Li, P

2001-07-05

A mathematical model has been developed for immobilized enzyme-catalyzed kinetic resolution of racemate in a fixed-bed reactor in which the enzyme-catalyzed reaction (the irreversible uni-uni competitive Michaelis-Menten kinetics is chosen as an example) was coupled with intraparticle diffusion, external mass transfer, and axial dispersion. The effects of mass-transfer limitations, competitive inhibition of substrates, deactivation on the enzyme effective enantioselectivity, and the optical purity and yield of the desired product are examined quantitatively over a wide range of parameters using the orthogonal collocation method. For a first-order reaction, an analytical solution is derived from the mathematical model for slab-, cylindrical-, and spherical-enzyme supports. Based on the analytical solution for the steady-state resolution process, a new concise formulation is presented to predict quantitatively the mass-transfer limitations on enzyme effective enantioselectivity and optical purity and yield of the desired product for a continuous steady-state kinetic resolution process in a fixed-bed reactor. Copyright 2001 John Wiley & Sons, Inc.

A receptor-targeted nanocomplex vector system optimized for respiratory gene transfer.

PubMed

Tagalakis, Aristides D; McAnulty, Robin J; Devaney, James; Bottoms, Stephen E; Wong, John B; Elbs, Martin; Writer, Michele J; Hailes, Helen C; Tabor, Alethea B; O'Callaghan, Christopher; Jaffe, Adam; Hart, Stephen L

2008-05-01

Synthetic vectors for cystic fibrosis (CF) gene therapy are required that efficiently and safely transfect airway epithelial cells, rather than alveolar epithelial cells or macrophages, and that are nonimmunogenic, thus allowing for repeated delivery. We have compared several vector systems against these criteria including GL67, polyethylenimine (PEI) 22 and 25 kd and two new, synthetic vector formulations, comprising a cationic, receptor-targeting peptide K(16)GACSERSMNFCG (E), and the cationic liposomes (L) DHDTMA/DOPE or DOSEP3/DOPE. The lipid and peptide formulations self assemble into receptor-targeted nanocomplexes (RTNs) LED-1 and LED-2, respectively, on mixing with plasmid (D). LED-1 transfected airway epithelium efficiently, while LED-2 and GL67 preferentially transfected alveolar cells. PEI transfected airway epithelial cells with high efficiency, but was more toxic to the mice than the other formulations. On repeat dosing, LED-1 was equally as effective as the single dose, while GL67 was 30% less effective and PEI 22 kd displayed a 90% reduction of efficiency on repeated delivery. LED-1 thus was the only formulation that fulfilled the criteria for a CF gene therapy vector while GL67 and LED-2 may be appropriate for other respiratory diseases. Opportunities for PEI depend on a solution to its toxicity problems. LED-1 formulations were stable to nebulization, the most appropriate delivery method for CF.

Transdermal delivery of flurbiprofen from surfactant-based vesicles: particle characterization and the effect of water on in vitro transport.

PubMed

Uchino, Tomonobu; Matsumoto, Yuiko; Murata, Akiko; Oka, Toshihiko; Miyazaki, Yasunori; Kagawa, Yoshiyuki

2014-04-10

Flurbiprofen loaded rigid and elastic vesicles comprising the bilayer-forming surfactant sucrose-ester laurate were prepared by the film rehydration and extrusion method. The charge-inducing agent sodium dodecyl sulfate, and the micelle-forming surfactants, sorbitan monolaurate, polyethylene glycol monolaurate, and polysorbate 20, were used to enhance elasticity. Vesicle formulations were evaluated for size, zeta potential, (1)H and (19)F nuclear magnetic resonance (NMR) spectra, and in vitro skin permeation across Yucatan micropig (YMP) skin. Vesicle formulations were stable for 2 weeks and their mean sizes were 95-135 nm. NMR spectroscopy showed that flurbiprofen molecular mobility was restricted by interaction with vesicle components because of entrapment in vesicle bilayers. Moreover, sorbitan monolaurate-containing vesicles strongly retained flurbiprofen molecules. After non-occlusive application to YMP skin, flurbiprofen transport from all vesicle formulations was superior to that of flurbiprofen alone and remarkably decreased after water vaporization. Polarization microscopy and small-angle X-ray diffraction analysis showed that the vesicle formulation was transferred to liquid crystalline state. Suppression of vesicle transition to the liquid crystalline state was observed with applications of both large quantities and diluted samples. The presence of water in the formulations was associated with maintenance of the vesicle structure and greater flurbiprofen transport across YMP skin. Copyright © 2014 Elsevier B.V. All rights reserved.

Managing a monotown as a priority social and economic development area

NASA Astrophysics Data System (ADS)

Trifonov, Vladimir; Loyko, Olga; Nesteruk, Dmitriy; Zhironkin, Sergey; Strekovtsova, Ekaterina

2017-01-01

The goal of the study is studying the specific features of organizing a priority social and economic development area (PSEDA) on the example of PSEDA "Yurga" in Kemerovo region (Russia). The problem is formulated as the question: which institutes, ideas, resources and management technologies may fuel transition to the new stage of the monotown development. The practical task is to determine the promising trends of development of single-industry municipalities on the example of the town of Yurga in Kemerovo region. In the paper we formulate the trends of developing sustainable urban environment of the monotown as of priority social and economic development area for further synergetic integration into higher order structures.

Quantitative Estimation of the Climatic Effects of Carbon Transferred by International Trade.

PubMed

Wei, Ting; Dong, Wenjie; Moore, John; Yan, Qing; Song, Yi; Yang, Zhiyong; Yuan, Wenping; Chou, Jieming; Cui, Xuefeng; Yan, Xiaodong; Wei, Zhigang; Guo, Yan; Yang, Shili; Tian, Di; Lin, Pengfei; Yang, Song; Wen, Zhiping; Lin, Hui; Chen, Min; Feng, Guolin; Jiang, Yundi; Zhu, Xian; Chen, Juan; Wei, Xin; Shi, Wen; Zhang, Zhiguo; Dong, Juan; Li, Yexin; Chen, Deliang

2016-06-22

Carbon transfer via international trade affects the spatial pattern of global carbon emissions by redistributing emissions related to production of goods and services. It has potential impacts on attribution of the responsibility of various countries for climate change and formulation of carbon-reduction policies. However, the effect of carbon transfer on climate change has not been quantified. Here, we present a quantitative estimate of climatic impacts of carbon transfer based on a simple CO2 Impulse Response Function and three Earth System Models. The results suggest that carbon transfer leads to a migration of CO2 by 0.1-3.9 ppm or 3-9% of the rise in the global atmospheric concentrations from developed countries to developing countries during 1990-2005 and potentially reduces the effectiveness of the Kyoto Protocol by up to 5.3%. However, the induced atmospheric CO2 concentration and climate changes (e.g., in temperature, ocean heat content, and sea-ice) are very small and lie within observed interannual variability. Given continuous growth of transferred carbon emissions and their proportion in global total carbon emissions, the climatic effect of traded carbon is likely to become more significant in the future, highlighting the need to consider carbon transfer in future climate negotiations.

Automated Dissolution for Enteric-Coated Aspirin Tablets: A Case Study for Method Transfer to a RoboDis II.

PubMed

Ibrahim, Sarah A; Martini, Luigi

2014-08-01

Dissolution method transfer is a complicated yet common process in the pharmaceutical industry. With increased pharmaceutical product manufacturing and dissolution acceptance requirements, dissolution testing has become one of the most labor-intensive quality control testing methods. There is an increased trend for automation in dissolution testing, particularly for large pharmaceutical companies to reduce variability and increase personnel efficiency. There is no official guideline for dissolution testing method transfer from a manual, semi-automated, to automated dissolution tester. In this study, a manual multipoint dissolution testing procedure for an enteric-coated aspirin tablet was transferred effectively and reproducibly to a fully automated dissolution testing device, RoboDis II. Enteric-coated aspirin samples were used as a model formulation to assess the feasibility and accuracy of media pH change during continuous automated dissolution testing. Several RoboDis II parameters were evaluated to ensure the integrity and equivalency of dissolution method transfer from a manual dissolution tester. This current study provides a systematic outline for the transfer of the manual dissolution testing protocol to an automated dissolution tester. This study further supports that automated dissolution testers compliant with regulatory requirements and similar to manual dissolution testers facilitate method transfer. © 2014 Society for Laboratory Automation and Screening.

Multiphysics Computational Analysis of a Solid-Core Nuclear Thermal Engine Thrust Chamber

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Canabal, Francisco; Cheng, Gary; Chen, Yen-Sen

2007-01-01

The objective of this effort is to develop an efficient and accurate computational heat transfer methodology to predict thermal, fluid, and hydrogen environments for a hypothetical solid-core, nuclear thermal engine - the Small Engine. In addition, the effects of power profile and hydrogen conversion on heat transfer efficiency and thrust performance were also investigated. The computational methodology is based on an unstructured-grid, pressure-based, all speeds, chemically reacting, computational fluid dynamics platform, while formulations of conjugate heat transfer were implemented to describe the heat transfer from solid to hydrogen inside the solid-core reactor. The computational domain covers the entire thrust chamber so that the afore-mentioned heat transfer effects impact the thrust performance directly. The result shows that the computed core-exit gas temperature, specific impulse, and core pressure drop agree well with those of design data for the Small Engine. Finite-rate chemistry is very important in predicting the proper energy balance as naturally occurring hydrogen decomposition is endothermic. Locally strong hydrogen conversion associated with centralized power profile gives poor heat transfer efficiency and lower thrust performance. On the other hand, uniform hydrogen conversion associated with a more uniform radial power profile achieves higher heat transfer efficiency, and higher thrust performance.

The application of remote sensing to the development and formulation of hydrologic planning models: Executive summary

NASA Technical Reports Server (NTRS)

Castruccio, P. A.; Loats, H. L., Jr.; Fowler, T. R.

1977-01-01

Methods for the reduction of remotely sensed data and its application in hydrologic land use assessment, surface water inventory, and soil property studies are presented. LANDSAT data is used to provide quantitative parameters and coefficients to construct watershed transfer functions for a hydrologic planning model aimed at estimating peak outflow from rainfall inputs.

Deformed transition-state theory: Deviation from Arrhenius behavior and application to bimolecular hydrogen transfer reaction rates in the tunneling regime.

PubMed

Carvalho-Silva, Valter H; Aquilanti, Vincenzo; de Oliveira, Heibbe C B; Mundim, Kleber C

2017-01-30

A formulation is presented for the application of tools from quantum chemistry and transition-state theory to phenomenologically cover cases where reaction rates deviate from Arrhenius law at low temperatures. A parameter d is introduced to describe the deviation for the systems from reaching the thermodynamic limit and is identified as the linearizing coefficient in the dependence of the inverse activation energy with inverse temperature. Its physical meaning is given and when deviation can be ascribed to quantum mechanical tunneling its value is calculated explicitly. Here, a new derivation is given of the previously established relationship of the parameter d with features of the barrier in the potential energy surface. The proposed variant of transition state theory permits comparison with experiments and tests against alternative formulations. Prescriptions are provided and implemented to three hydrogen transfer reactions: CH 4  + OH → CH 3  + H 2 O, CH 3 Cl + OH → CH 2 Cl + H 2 O and H 2  + CN → H + HCN, widely investigated both experimentally and theoretically. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Crystalline structure of the marketed form of Rifampicin: a case of conformational and charge transfer polymorphism

NASA Astrophysics Data System (ADS)

de Pinho Pessoa Nogueira, Luciana; de Oliveira, Yara S.; de C. Fonseca, Jéssica; Costa, Wendell S.; Raffin, Fernanda N.; Ellena, Javier; Ayala, Alejandro Pedro

2018-03-01

Rifampicin is a semi-synthetic drug derived from rifamycin B, and currently integrates the fixed dose combination tablet formulations used in the treatment of tuberculosis. It is also used in the leprosy polychemotherapy and prophylaxis, which are diseases classified as neglected according to the World Health Organization. Rifampicin is a polymorphic drug and its desirable polymorphic form is labeled as II, being the main goal of this study the elucidation of its crystalline structure. Polymorph II is characterized by two molecules with different conformations in the asymmetric unit and the following lattice parameters: a = 14.0760 (10) Å, b = 17.5450 (10) Å, c = 17.5270 (10) Å, β = 92.15°. Differently to the previously reported structures, a charge transference from the hydroxyl group of the naphthoquinone of one conformer to the nitrogen of the piperazine group of the second conformer was observed. The relevance of the knowledge of this crystalline structure, which is the preferred polymorph for pharmaceutical formulations, was evidenced by analyzing raw materials with polymorphic mixtures. Thus, the results presented in this contribution close an old information gap allowing the complete solid-state characterization of rifampicin.

Laser short-pulse heating of an aluminum thin film: Energy transfer in electron and lattice sub-systems

NASA Astrophysics Data System (ADS)

Bin Mansoor, Saad; Sami Yilbas, Bekir

2015-08-01

Laser short-pulse heating of an aluminum thin film is considered and energy transfer in the film is formulated using the Boltzmann equation. Since the heating duration is short and the film thickness is considerably small, thermal separation of electron and lattice sub-systems is incorporated in the analysis. The electron-phonon coupling is used to formulate thermal communication of both sub-systems during the heating period. Equivalent equilibrium temperature is introduced to account for the average energy of all phonons around a local point when they redistribute adiabatically to an equilibrium state. Temperature predictions of the Boltzmann equation are compared with those obtained from the two-equation model. It is found that temperature predictions from the Boltzmann equation differ slightly from the two-equation model results. Temporal variation of equivalent equilibrium temperature does not follow the laser pulse intensity in the electron sub-system. The time occurrence of the peak equivalent equilibrium temperature differs for electron and lattice sub-systems, which is attributed to phonon scattering in the irradiated field in the lattice sub-system. In this case, time shift is observed for occurrence of the peak temperature in the lattice sub-system.

Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine, NASA Advanced Air Vehicles Program - Commercial Supersonic Technology Project - AeroServoElasticity

NASA Technical Reports Server (NTRS)

Kopasakis, George; Connolly, Joseph W.; Cheng, Larry

2015-01-01

This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.

Microwave model prediction and verifications for vegetated terrain

NASA Technical Reports Server (NTRS)

Fung, A. K.

1985-01-01

To understand the scattering properties of a deciduous and a coniferous type vegetation scattering models were developed assuming either a disc type leaf or a needle type leaf. The major effort is to calculate the corresponding scattering phase functions and then each of the functions is used in a radiative transfer formulation to compute the scattering intensity and consequently the scattering coefficient. The radiative transfer formulation takes into account the irregular ground surface by including the rough soil surface in the boundary condition. Thus, the scattering model accounts for volume scattering inside the vegetation layer, the surface scattering from the ground and the interaction between scattering from the soil surface and the vegetation volume. The contribution to backscattering by each of the three scattering mechanisms is illustrated along with the effects of each layer or surface parameter. The major difference between the two types of vegetation is that when the incident wavelength is comparable to the size of the leaf there is a peak appearing in the mid angular region of the backscattering curve for the disc type leaf whereas it is a dip in the same region for a needle type leaf.

Formulation to target delivery to the ciliary body and choroid via the suprachoroidal space of the eye using microneedles.

PubMed

Kim, Yoo Chun; Oh, Kyung Hee; Edelhauser, Henry F; Prausnitz, Mark R

2015-09-01

In this work, we tested the hypothesis that particles injected into the suprachoroidal space can be localized at the site of injection or broadly distributed throughout the suprachoroidal space by controlling polymeric formulation properties. Single hollow microneedles were inserted into the sclera of New Zealand White rabbits and injected non-biodegradable fluorescently tagged nanoparticles and microparticles suspended in polymeric formulations into the suprachoroidal space of the eye. When formulated in saline, the particles were distributed over 29-42% of the suprachoroidal space immediately after injection. To spread particles over larger areas of the choroidal surface, addition of hyaluronic acid to make moderately non-Newtonian solutions increased particle spread to up to 100% of the suprachoroidal space. To localize particles at the site of injection adjacent to the ciliary body, strongly non-Newtonian polymer solutions localized particles to 8.3-20% of the suprachoroidal space, which exhibited a small increase in area over the course of two months. This study demonstrates targeted particle delivery within the suprachoroidal space using polymer formulations that spread particles over the whole choroidal surface or localized them adjacent to the ciliary body after injection. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 63.10886 - What are my management practices for binder formulations?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Area Sources Pollution Prevention Management Practices for New and Existing Affected Sources § 63.10886 What are my management practices for binder formulations? For each furfuryl alcohol warm box mold or... does not apply to the resin portion of the binder system. Requirements for New and Existing Affected...

40 CFR 63.10886 - What are my management practices for binder formulations?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Area Sources Pollution Prevention Management Practices for New and Existing Affected Sources § 63.10886 What are my management practices for binder formulations? For each furfuryl alcohol warm box mold or... does not apply to the resin portion of the binder system. Requirements for New and Existing Affected...

40 CFR 63.10886 - What are my management practices for binder formulations?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Area Sources Pollution Prevention Management Practices for New and Existing Affected Sources § 63.10886 What are my management practices for binder formulations? For each furfuryl alcohol warm box mold or... does not apply to the resin portion of the binder system. Requirements for New and Existing Affected...

40 CFR 63.10886 - What are my management practices for binder formulations?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Area Sources Pollution Prevention Management Practices for New and Existing Affected Sources § 63.10886 What are my management practices for binder formulations? For each furfuryl alcohol warm box mold or... does not apply to the resin portion of the binder system. Requirements for New and Existing Affected...

Improved ant colony optimization for optimal crop and irrigation water allocation by incorporating domain knowledge

USDA-ARS?s Scientific Manuscript database

An improved ant colony optimization (ACO) formulation for the allocation of crops and water to different irrigation areas is developed. The formulation enables dynamic adjustment of decision variable options and makes use of visibility factors (VFs, the domain knowledge that can be used to identify ...

An Advanced One-Dimensional Finite Element Model for Incompressible Thermally Expandable Flow

DOE PAGES

Hu, Rui

2017-03-27

Here, this paper provides an overview of a new one-dimensional finite element flow model for incompressible but thermally expandable flow. The flow model was developed for use in system analysis tools for whole-plant safety analysis of sodium fast reactors. Although the pressure-based formulation was implemented, the use of integral equations in the conservative form ensured the conservation laws of the fluid. A stabilization scheme based on streamline-upwind/Petrov-Galerkin and pressure-stabilizing/Petrov-Galerkin formulations is also introduced. The flow model and its implementation have been verified by many test problems, including density wave propagation, steep gradient problems, discharging between tanks, and the conjugate heatmore » transfer in a heat exchanger.« less

An Advanced One-Dimensional Finite Element Model for Incompressible Thermally Expandable Flow

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

Hu, Rui

Here, this paper provides an overview of a new one-dimensional finite element flow model for incompressible but thermally expandable flow. The flow model was developed for use in system analysis tools for whole-plant safety analysis of sodium fast reactors. Although the pressure-based formulation was implemented, the use of integral equations in the conservative form ensured the conservation laws of the fluid. A stabilization scheme based on streamline-upwind/Petrov-Galerkin and pressure-stabilizing/Petrov-Galerkin formulations is also introduced. The flow model and its implementation have been verified by many test problems, including density wave propagation, steep gradient problems, discharging between tanks, and the conjugate heatmore » transfer in a heat exchanger.« less

Relative role of transfer zones in controlling sequence stacking patterns and facies distribution: insights from the Fushan Depression, South China Sea

NASA Astrophysics Data System (ADS)

Liu, Entao; Wang, Hua; Li, Yuan; Huang, Chuanyan

2015-04-01

In sedimentary basins, a transfer zone can be defined as a coordinated system of deformational features which has good prospects for hydrocarbon exploration. Although the term 'transfer zone' has been widely applied to the study of extensional basins, little attention has been paid to its controlling effect on sequence tracking pattern and depositional facies distribution. Fushan Depression is a half-graben rift sub-basin, located in the southeast of the Beibuwan Basin, South China Sea. In this study, comparative analysis of seismic reflection, palaeogeomorphology, fault activity and depositional facies distribution in the southern slope indicates that three different types of sequence stacking patterns (i.e. multi-level step-fault belt in the western area, flexure slope belt in the central area, gentle slope belt in the eastern area) were developed along the southern slope, together with a large-scale transfer zone in the central area, at the intersection of the western and eastern fault systems. Further analysis shows that the transfer zone played an important role in the diversity of sequence stacking patterns in the southern slope by dividing the Fushan Depression into two non-interfering tectonic systems forming different sequence patterns, and leading to the formation of the flexure slope belt in the central area. The transfer zone had an important controlling effect on not only the diversity of sequence tracking patterns, but also the facies distribution on the relay ramp. During the high-stand stage, under the controlling effect of the transfer zone, the sediments contain a significant proportion of coarser material accumulated and distributed along the ramp axis. By contrast, during the low-stand stage, the transfer zone did not seem to contribute significantly to the low-stand fan distribution which was mainly controlled by the slope gradient (palaeogeomorphology). Therefore, analysis of the transfer zone can provide a new perspective for basin analysis. In addition, the transfer zone area demonstrated unique hydrocarbon accumulation models different from the western and eastern areas. It was not only a structural high combined with sufficient coarse-grained reservoir quality sands, but was also associated with large-scale sublacustrine fan deposits with high quality reservoirs, indicating that the recognition of transfer zones can improve the prediction of hydrocarbon occurrences in similar settings.

Airborne concentrations of benzene associated with the historical use of some formulations of liquid wrench.

PubMed

Williams, Pamela R D; Knutsen, Jeffrey S; Atkinson, Chris; Madl, Amy K; Paustenbach, Dennis J

2007-08-01

The current study characterizes potential inhalation exposures to benzene associated with the historical use of some formulations of Liquid Wrench under specific test conditions. This product is a multiuse penetrant and lubricant commonly used in a variety of consumer and industrial settings. The study entailed the remanufacturing of several product formulations to have similar physical and chemical properties to most nonaerosol Liquid Wrench formulations between 1960 and 1978. The airborne concentrations of benzene and other constituents during the simulated application of these products were measured under a range of conditions. Nearly 200 breathing zone and area bystander air samples were collected during 11 different product use scenarios. Depending on the tests performed, average airborne concentrations of benzene ranged from approximately 0.2-9.9 mg/m(3) (0.08-3.8 ppm) for the 15-min personal samples; 0.1-8 mg/m(3) (0.04-3 ppm) for the 1-hr personal samples; and 0.1-5.1 mg/m(3) (0.04-2 ppm) for the 1-hr area samples. The 1-hr personal samples encompassed two 15-min product applications and two 15-min periods of standing within 5 to 10 feet of the work area. The measured airborne concentrations of benzene varied significantly based on the benzene content of the formulation tested (1%, 3%, 14%, or 30% v/v benzene) and the indoor air exchange rate but did not vary much with the base formulation of the product or the two quantities of Liquid Wrench used. The airborne concentrations of five other volatile chemicals (ethylbenzene, toluene, total xylenes, cyclohexane, and hexane) were also measured, and the results were consistent with the volatility and concentrations of these chemicals in the product tested. A linear regression analysis of air concentration compared with the chemical mole fraction in the solution and air exchange rate provided a relatively good fit to the data. The results of this study should be useful for evaluating potential inhalation exposures to benzene and other volatile chemicals that occurred during the past use of some formulations of Liquid Wrench and perhaps for some similar products containing these chemicals.

Technology transfer within the government

NASA Technical Reports Server (NTRS)

Russell, John

1992-01-01

The report of a workshop panel concerned with technology transfer within the government is presented. The presentation is made in vugraph form. The assigned subtopic for this panel are as follows: (1) transfer from non-NASA US government technology developers to NASA space missions/programs; and (2) transfer from NASA to other US government space mission programs. A specific area of inquiry was Technology Maturation Milestones. Three areas were investigated: technology development; advanced development; and flight hardware development.

Using Six Sigma methodology to reduce patient transfer times from floor to critical-care beds.

PubMed

Silich, Stephan J; Wetz, Robert V; Riebling, Nancy; Coleman, Christine; Khoueiry, Georges; Abi Rafeh, Nidal; Bagon, Emma; Szerszen, Anita

2012-01-01

In response to concerns regarding delays in transferring critically ill patients to intensive care units (ICU), a quality improvement project, using the Six Sigma process, was undertaken to correct issues leading to transfer delay. To test the efficacy of a Six Sigma intervention to reduce transfer time and establish a patient transfer process that would effectively enhance communication between hospital caregivers and improve the continuum of care for patients. The project was conducted at a 714-bed tertiary care hospital in Staten Island, New York. A Six Sigma multidisciplinary team was assembled to assess areas that needed improvement, manage the intervention, and analyze the results. The Six Sigma process identified eight key steps in the transfer of patients from general medical floors to critical care areas. Preintervention data and a root-cause analysis helped to establish the goal transfer-time limits of 3 h for any individual transfer and 90 min for the average of all transfers. The Six Sigma approach is a problem-solving methodology that resulted in almost a 60% reduction in patient transfer time from a general medical floor to a critical care area. The Six Sigma process is a feasible method for implementing healthcare related quality of care projects, especially those that are complex. © 2011 National Association for Healthcare Quality.

Plasmodium Genus Assay Transition to the Joint Biological Agent Identification and Diagnostic System (JBAIDS)

DTIC Science & Technology

2012-07-12

readily transferable to diverse real-time PCR instrumentation. These assays are used regularly for vector surveillance and are the primary...instrumentation ( FilmArray ) is under assessment. Assay oligonucleotide sequences and formulations are available for use in future joint projects...Plasmodium real-time PCR detection capability has been challenging. During 2006, the Division of Entomology, WRAIR designed and developed a

Incorporating Learning Outcomes in Transfer Credit: The Way Forward for Campus Alberta?

ERIC Educational Resources Information Center

Kennepohl, Dietmar K.

2016-01-01

Learning outcomes have become an integral part of the global trend in higher education reform and are employed in three interconnected areas: (1) quality assurance, (2) teaching and learning, and (3) transfer credit. The article touches briefly on the first two areas, but focuses discussion on employing learning outcomes in transfer credit. Using…

A novel methodology for radiative transfer in a planetary atmosphere. I - The functions a exponent m and b exponent m of anisotropic scattering

NASA Technical Reports Server (NTRS)

Fymat, A. L.; Kalaba, R. E.

1977-01-01

The original problem of anisotropic scattering in an atmosphere illuminated by a unidirectional source is replaced by an analogous formulation where the incident light is omnidirectional. A radiative-transfer equation for the omnidirectional case is obtained in which the direction of illumination plays no role and the source-function analog, Sobolev's (1972) source function Phi exponent m, contains only a single integral term. For radiation incident on the top or the bottom of the atmosphere, this equation involves the functions b exponent m and h exponent m, respectively, with m corresponding to the order of the harmonic component of the scattered radiation field; these two functions are shown to be only one through some simple reciprocity relations. The transfer problem is then reformulated for the function a exponent m, in which case the source-function analog (Sobolev's function D exponent m) involves incident direction.

Ligand reorganization and activation energies in nonadiabatic electron transfer reactions

NASA Astrophysics Data System (ADS)

Zhu, Jianjun; Wang, Jianji; Stell, George

2006-10-01

The activation energy and ligand reorganization energy for nonadiabatic electron transfer reactions in chemical and biological systems are investigated in this paper. The free energy surfaces and the activation energy are derived exactly in the general case in which the ligand vibration frequencies are not equal. The activation energy is derived by free energy minimization at the transition state. Our formulation leads to the Marcus-Hush [J. Chem. Phys. 24, 979 (1956); 98, 7170 (1994); 28, 962 (1958)] results in the equal-frequency limit and also generalizes the Marcus-Sumi [J. Chem. Phys. 84, 4894 (1986)] model in the context of studying the solvent dynamic effect on electron transfer reactions. It is found that when the ligand vibration frequencies are different, the activation energy derived from the Marcus-Hush formula deviates by 5%-10% from the exact value. If the reduced reorganization energy approximation is introduced in the Marcus-Hush formula, the result is almost exact.

Analysis of Material Sample Heated by Impinging Hot Hydrogen Jet in a Non-Nuclear Tester

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Foote, John; Litchford, Ron

2006-01-01

A computational conjugate heat transfer methodology was developed and anchored with data obtained from a hot-hydrogen jet heated, non-nuclear materials tester, as a first step towards developing an efficient and accurate multiphysics, thermo-fluid computational methodology to predict environments for hypothetical solid-core, nuclear thermal engine thrust chamber. The computational methodology is based on a multidimensional, finite-volume, turbulent, chemically reacting, thermally radiating, unstructured-grid, and pressure-based formulation. The multiphysics invoked in this study include hydrogen dissociation kinetics and thermodynamics, turbulent flow, convective and thermal radiative, and conjugate heat transfers. Predicted hot hydrogen jet and material surface temperatures were compared with those of measurement. Predicted solid temperatures were compared with those obtained with a standard heat transfer code. The interrogation of physics revealed that reactions of hydrogen dissociation and recombination are highly correlated with local temperature and are necessary for accurate prediction of the hot-hydrogen jet temperature.

Determination of optimum fin profile for a zero-G capillary drained condenser

NASA Technical Reports Server (NTRS)

Mccormick, John A.; Valenzuela, Javier A.; Choudhury, Dipanker

1990-01-01

This paper presents the analytical formulation and numerical results for heat transfer in a high heat flux condenser that relies on capillary flow along shaped fins (Gregorig surfaces) and a drainage network embedded in the condenser walls. Results are shown for a variety of fin profile shapes in order to show the geometric trade-offs involved in seeking a maximum effective heat transfer coefficient for the fin. Predictions of the model show excellent agreement with previously reported measurements for steam. Based on this work, a profile has been selected for a 2 kW ammonia condenser currently under development for use in space. In that design the fin half width is 0.5 mm and the model predicts a heat transfer coefficient referred to the base of the fin of 9 W/sq cm deg C for a heat flux of 10/W sq cm at the base.

Fuel-optimal trajectories of aeroassisted orbital transfer with plane change

NASA Technical Reports Server (NTRS)

Naidu, Desineni Subbaramaiah; Hibey, Joseph L.

1989-01-01

The problem of minimization of fuel consumption during the atmospheric portion of an aeroassisted, orbital transfer with plane change is addressed. The complete mission has required three characteristic velocities, a deorbit impulse at high earth orbit (HEO), a boost impulse at the atmospheric exit, and a reorbit impulse at low earth orbit (LEO). A performance index has been formulated as the sum of these three impulses. Application of optimal control principles has led to a nonlinear, two-point, boundary value problem which was solved by using a multiple shooting algorithm. The strategy for the atmospheric portion of the minimum-fuel transfer is to start initially with the maximum positive lift in order to recover from the downward plunge, and then to fly with a gradually decreasing lift such that the vehicle skips out of the atmosphere with a flight path angle near zero degrees.

Polarimetric signatures of a coniferous forest canopy based on vector radiative transfer theory

NASA Technical Reports Server (NTRS)

Karam, M. A.; Fung, A. K.; Amar, F.; Mougin, E.; Lopes, A.; Beaudoin, A.

1992-01-01

Complete polarization signatures of a coniferous forest canopy are studied by the iterative solution of the vector radiative transfer equations up to the second order. The forest canopy constituents (leaves, branches, stems, and trunk) are embedded in a multi-layered medium over a rough interface. The branches, stems and trunk scatterers are modeled as finite randomly oriented cylinders. The leaves are modeled as randomly oriented needles. For a plane wave exciting the canopy, the average Mueller matrix is formulated in terms of the iterative solution of the radiative transfer solution and used to determine the linearly polarized backscattering coefficients, the co-polarized and cross-polarized power returns, and the phase difference statistics. Numerical results are presented to investigate the effect of transmitting and receiving antenna configurations on the polarimetric signature of a pine forest. Comparison is made with measurements.

Modulation transfer function cascade model for a sampled IR imaging system.

PubMed

de Luca, L; Cardone, G

1991-05-01

The performance of the infrared scanning radiometer (IRSR) is strongly stressed in convective heat transfer applications where high spatial frequencies in the signal that describes the thermal image are present. The need to characterize more deeply the system spatial resolution has led to the formulation of a cascade model for the evaluation of the actual modulation transfer function of a sampled IR imaging system. The model can yield both the aliasing band and the averaged modulation response for a general sampling subsystem. For a line scan imaging system, which is the case of a typical IRSR, a rule of thumb that states whether the combined sampling-imaging system is either imaging-dependent or sampling-dependent is proposed. The model is tested by comparing it with other noncascade models as well as by ad hoc measurements performed on a commercial digitized IRSR.

Low lift-to-drag aero-assisted orbit transfer vehicles

NASA Technical Reports Server (NTRS)

Andrews, D. G.; Savage, R. T.

1984-01-01

The results of systems analysis conducted on low life drag ratio (L/D) aero-assisted orbit transfer vehicle (AOTV's) are presented. The objectives for this class of vehicle and formulate technology development plans and funding levels to bring the required technologies to readiness levels, as well as develop a credible decision data base encompassing the entire range of low L/D concepts for use in future NASA Aeroassist Orbit Transfer Vehicles studies. Each candidate low L/D concept, the aerobrake, the lifting brake, and the aeromaneuvering concept could be made to work with technologies achievable by the early 1990's. All concepts require flexible structure with flexible thermal protection system (TPS) to be successfully integrated into the shuttle orbiter for launch, all required improvements in guidance and control to fly the dispersed atmospheres at high altitude, and all concepts had potential to evolve from ground-based to space-based operations.

Viral Vectors for In Vivo Gene Transfer in Parkinson’s disease: Properties and Clinical Grade Production

PubMed Central

Burger, Corinna; Snyder, Richard O.

2009-01-01

Because Parkinson’s disease is a progressive degenerative disorder that is mainly confined to the basal ganglia, gene transfer to deliver therapeutic molecules is an attractive treatment avenue. The present review focuses on direct in vivo gene transfer vectors that have been developed to a degree that they have been successfully used in animal model of Parkinson’s disease. Accordingly, the properties of recombinant adenovirus, recombinant adeno-associated virus, herpes simplex virus, and lentivirus are described and contrasted. In order for viral vectors to be developed into clinical grade reagents, they must be manufactured and tested to precise regulatory standards. Indeed, clinical lots of viral vectors can be produced in compliance with current Good Manufacturing Practices (cGMPs) regulations using industry accepted manufacturing methodologies, manufacturing controls, and quality systems. The viral vector properties themselves combined with physiological product formulations facilitate long-term storage and direct in vivo administration. PMID:17916354

The 300 Area Integrated Field Research Challenge Quality Assurance Project Plan

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

Fix, N. J.

Pacific Northwest National Laboratory and a group of expert collaborators are using the U.S. Department of Energy Hanford Site 300 Area uranium plume within the footprint of the 300-FF-5 groundwater operable unit as a site for an Integrated Field-Scale Subsurface Research Challenge (IFRC). The IFRC is entitled Multi-Scale Mass Transfer Processes Controlling Natural Attenuation and Engineered Remediation: An IFRC Focused on the Hanford Site 300 Area Uranium Plume Project. The theme is investigation of multi-scale mass transfer processes. A series of forefront science questions on mass transfer are posed for research that relate to the effect of spatial heterogeneities; themore » importance of scale; coupled interactions between biogeochemical, hydrologic, and mass transfer processes; and measurements/approaches needed to characterize and model a mass transfer-dominated system. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by the 300 Area IFRC Project. This plan is designed to be used exclusively by project staff.« less

Systems identification technology development for large space systems

NASA Technical Reports Server (NTRS)

Armstrong, E. S.

1982-01-01

A methodology for synthesizinng systems identification, both parameter and state, estimation and related control schemes for flexible aerospace structures is developed with emphasis on the Maypole hoop column antenna as a real world application. Modeling studies of the Maypole cable hoop membrane type antenna are conducted using a transfer matrix numerical analysis approach. This methodology was chosen as particularly well suited for handling a large number of antenna configurations of a generic type. A dedicated transfer matrix analysis, both by virtue of its specialization and the inherently easy compartmentalization of the formulation and numerical procedures, is significantly more efficient not only in computer time required but, more importantly, in the time needed to review and interpret the results.

Graphene-epoxy flexible transparent capacitor obtained by graphene-polymer transfer and UV-induced bonding.

PubMed

Sangermano, Marco; Chiolerio, Alessandro; Veronese, Giulio Paolo; Ortolani, Luca; Rizzoli, Rita; Mancarella, Fulvio; Morandi, Vittorio

2014-02-01

A new approach is reported for the preparation of a graphene-epoxy flexible transparent capacitor obtained by graphene-polymer transfer and UV-induced bonding. SU8 resin is employed for realizing a well-adherent, transparent, and flexible supporting layer. The achieved transparent graphene/SU8 membrane presents two distinct surfaces: one homogeneous conductive surface containing a graphene layer and one dielectric surface typical of the epoxy polymer. Two graphene/SU8 layers are bonded together by using an epoxy photocurable formulation based on epoxy resin. The obtained material showed a stable and clear capacitive behavior. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Charge transfer excitations from exact and approximate ensemble Kohn-Sham theory

NASA Astrophysics Data System (ADS)

Gould, Tim; Kronik, Leeor; Pittalis, Stefano

2018-05-01

By studying the lowest excitations of an exactly solvable one-dimensional soft-Coulomb molecular model, we show that components of Kohn-Sham ensembles can be used to describe charge transfer processes. Furthermore, we compute the approximate excitation energies obtained by using the exact ensemble densities in the recently formulated ensemble Hartree-exchange theory [T. Gould and S. Pittalis, Phys. Rev. Lett. 119, 243001 (2017)]. Remarkably, our results show that triplet excitations are accurately reproduced across a dissociation curve in all cases tested, even in systems where ground state energies are poor due to strong static correlations. Singlet excitations exhibit larger deviations from exact results but are still reproduced semi-quantitatively.

Temperature distribution of thick thermoset composites

NASA Astrophysics Data System (ADS)

Guo, Zhan-Sheng; Du, Shanyi; Zhang, Boming

2004-05-01

The development of temperature distribution of thick polymeric matrix laminates during an autoclave vacuum bag process was measured and compared with numerically calculated results. The finite element formulation of the transient heat transfer problem was carried out for polymeric matrix composite materials from the heat transfer differential equations including internal heat generation produced by exothermic chemical reactions. Software based on the general finite element software package was developed for numerical simulation of the entire composite process. From the experimental and numerical results, it was found that the measured temperature profiles were in good agreement with the numerical ones, and conventional cure cycles recommended by prepreg manufacturers for thin laminates should be modified to prevent temperature overshoot.

An explicit canopy BRDF model and inversion. [Bidirectional Reflectance Distribution Function

NASA Technical Reports Server (NTRS)

Liang, Shunlin; Strahler, Alan H.

1992-01-01

Based on a rigorous canopy radiative transfer equation, the multiple scattering radiance is approximated by the asymptotic theory, and the single scattering radiance calculation, which requires an numerical intergration due to considering the hotspot effect, is simplified. A new formulation is presented to obtain more exact angular dependence of the sky radiance distribution. The unscattered solar radiance and single scattering radiance are calculated exactly, and the multiple scattering is approximated by the delta two-stream atmospheric radiative transfer model. The numerical algorithms prove that the parametric canopy model is very accurate, especially when the viewing angles are smaller than 55 deg. The Powell algorithm is used to retrieve biospheric parameters from the ground measured multiangle observations.

7 CFR 932.54 - Transfers.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., the transferring handler shall comply with all applicable regulations up to the time of such transfer... 7 Agriculture 8 2014-01-01 2014-01-01 false Transfers. 932.54 Section 932.54 Agriculture... Regulating Handling Regulations § 932.54 Transfers. Transfers within the area of olives from one handler to...

7 CFR 932.54 - Transfers.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., the transferring handler shall comply with all applicable regulations up to the time of such transfer... 7 Agriculture 8 2010-01-01 2010-01-01 false Transfers. 932.54 Section 932.54 Agriculture... Regulating Handling Regulations § 932.54 Transfers. Transfers within the area of olives from one handler to...

7 CFR 932.54 - Transfers.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., the transferring handler shall comply with all applicable regulations up to the time of such transfer... 7 Agriculture 8 2012-01-01 2012-01-01 false Transfers. 932.54 Section 932.54 Agriculture... Regulating Handling Regulations § 932.54 Transfers. Transfers within the area of olives from one handler to...

7 CFR 932.54 - Transfers.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., the transferring handler shall comply with all applicable regulations up to the time of such transfer... 7 Agriculture 8 2013-01-01 2013-01-01 false Transfers. 932.54 Section 932.54 Agriculture... Regulating Handling Regulations § 932.54 Transfers. Transfers within the area of olives from one handler to...

7 CFR 932.54 - Transfers.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., the transferring handler shall comply with all applicable regulations up to the time of such transfer... 7 Agriculture 8 2011-01-01 2011-01-01 false Transfers. 932.54 Section 932.54 Agriculture... Regulating Handling Regulations § 932.54 Transfers. Transfers within the area of olives from one handler to...

A one-layer satellite surface energy balance for estimating evapotranspiration rates and crop water stress indexes.

PubMed

Barbagallo, Salvatore; Consoli, Simona; Russo, Alfonso

2009-01-01

Daily evapotranspiration fluxes over the semi-arid Catania Plain area (Eastern Sicily, Italy) were evaluated using remotely sensed data from Landsat Thematic Mapper TM5 images. A one-source parameterization of the surface sensible heat flux exchange using satellite surface temperature has been used. The transfer of sensible and latent heat is described by aerodynamic resistance and surface resistance. Required model inputs are brightness, temperature, fractional vegetation cover or leaf area index, albedo, crop height, roughness lengths, net radiation, air temperature, air humidity and wind speed. The aerodynamic resistance (r(ah)) is formulated on the basis of the Monin-Obukhov surface layer similarity theory and the surface resistance (r(s)) is evaluated from the energy balance equation. The instantaneous surface flux values were converted into evaporative fraction (EF) over the heterogeneous land surface to derive daily evapotranspiration values. Remote sensing-based assessments of crop water stress (CWSI) were also made in order to identify local irrigation requirements. Evapotranspiration data and crop coefficient values obtained from the approach were compared with: (i) data from the semi-empirical approach "K(c) reflectance-based", which integrates satellite data in the visible and NIR regions of the electromagnetic spectrum with ground-based measurements and (ii) surface energy flux measurements collected from a micrometeorological tower located in the experiment area. The expected variability associated with ET flux measurements suggests that the approach-derived surface fluxes were in acceptable agreement with the observations.

Design and physicochemical stability studies of paediatric oral formulations of sildenafil.

PubMed

Provenza, N; Calpena, A C; Mallandrich, M; Halbaut, L; Clares, B

2014-01-02

Personalized medicine is a challenging research area in paediatric treatments. Elaborating new paediatric formulations when no commercial forms are available is a common practice in pharmacy laboratories; among these, oral liquid formulations are the most common. But due to the lack of specialized equipment, frequently studies to assure the efficiency and safety of the final medicine cannot be carried out. Thus the purpose of this work was the development, characterization and stability evaluation of two oral formulations of sildenafil for the treatment of neonatal persistent pulmonary hypertension. After the establishment of a standard operating procedure (SOP) and elaboration, the physicochemical stability parameters appearance, pH, particle size, rheological behaviour and drug content of formulations were evaluated at three different temperatures for 90 days. Equally, prediction of long term stability, as well as, microbiological stability was performed. Formulations resulted in a suspension and a solution slightly coloured exhibiting fruity odour. Formulation I (suspension) exhibited the best physicochemical properties including Newtonian behaviour and uniformity of API content above 90% to assure an exact dosification process. Copyright © 2013 Elsevier B.V. All rights reserved.

In vivo skin effects of a dimethylaminoethanol (DMAE) based formulation.

PubMed

Tadini, K A; Campos, P M B G Maia

2009-12-01

Dimethylaminoethanol (DMAE) has been used in anti-aging formulations but few scientifically based data address its efficacy. The aim of this study was to evaluate the effects of DMAE-based formulations on hairless mice and human skin. Formulations containing with or without DMAE were applied to the dorsum of hairless mice. Histopathological and histometric evaluations were carried out after seven days. Formulations were also applied to the ventral forearm and the lateral periocular area of human volunteers. Stratum corneum water content and skin mechanical properties were analyzed using Corneometer and Cutometer, before and after a single and repeated application. Histometric evaluations showed that formulations with or without DMAE increased the viable epidermis thickness, but only the DMAE-supplemented formulation led to increased dermal thickness. DMAE also induced increase in collagen fiber thickness, which was observed in the histopathological study. After the single and the 8-week period application on human skin, formulations with and without DMAE enhanced the stratum corneum water content in the forearm skin. Mechanical properties were not significantly modified. So, we can suggest that DMAE action is related to its effects on the dermis as observed in the histopathological and histometric studies and showed hydration effects on skin.

Pharmacokinetics of gabapentin in a novel gastric-retentive extended-release formulation: comparison with an immediate-release formulation and effect of dose escalation and food.

PubMed

Chen, Cuiping; Cowles, Verne E; Hou, Eddie

2011-03-01

The objectives of the 3 phase I studies described herein were (1) to compare the pharmacokinetics of gabapentin delivered from a novel gastric-retentive dosage form vs an immediate-release formulation, (2) to assess the dose proportionality of the gastric-retentive extended-release formulation, and (3) to determine the effect of food on the pharmacokinetics of gabapentin delivered from this formulation. The time to reach maximum plasma concentration (t(max)) was extended for gabapentin delivered from the gastric-retentive extended-release formulation compared with the immediate-release formulation. A dose-related increase in both the maximum plasma concentration (C(max)) and the area under the plasma concentration-time curve (AUC) was observed as the gabapentin dose increased from 600 to 2400 mg. Fed status and increased fat content delayed t(max) and enhanced C(max) and AUC in proportion to the fat content. The pharmacokinetics of gabapentin delivered from this extended-release formulation allows a reduced dosing frequency while maintaining bioavailability and possibly diminishing the occurrence of adverse events attributable to a slower increase to the peak concentration compared with the immediate-release dosage form.

The role of service areas in the optimization of FSS orbital and frequency assignments

NASA Technical Reports Server (NTRS)

Levis, C. A.; Wang, C. W.; Yamamura, Y.; Reilly, C. H.; Gonsalvez, D. J.

1985-01-01

A relationship is derived, on a single-entry interference basis, for the minimum allowable spacing between two satellites as a function of electrical parameters and service-area geometries. For circular beams, universal curves relate the topocentric satellite spacing angle to the service-area separation angle measured at the satellite. The corresponding geocentric spacing depends only weakly on the mean longitude of the two satellites, and this is true also for alliptical antenna beams. As a consequence, if frequency channels are preassigned, the orbital assignment synthesis of a satellite system can be formulated as a mixed-integer programming (MIP) problem or approximated by a linear programming (LP) problem, with the interference protection requirements enforced by constraints while some linear function is optimized. Possible objective-function choices are discussed and explicit formulations are presented for the choice of the sum of the absolute deviations of the orbital locations from some prescribed ideal location set. A test problem is posed consisting of six service areas, each served by one satellite, all using elliptical antenna beams and the same frequency channels. Numerical results are given for the three ideal location prescriptions for both the MIP and LP formulations. The resulting scenarios also satisfy reasonable aggregate interference protection requirements.

139. VIEW OF AGENA TRANSFER AREA SHELTER (117A), LSB (BLDG. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

139. VIEW OF AGENA TRANSFER AREA SHELTER (117A), LSB (BLDG. 770), FROM VEHICLE CHECKOUT AREA (117). STAINLESS STEEL FLOOR SQUARE BY LOCKER WAS LEVEL PEDESTAL. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

[Relative bioavailability study of two oral formulations of mycophenolate mofetil in healthy volunteers].

PubMed

Saavedra S, Iván; Sasso A, Jaime; Quiñones S, Luis; Saavedra B, Mónica; Gaete G, Leonardo; Boza T, Ignacio; Carvajal H, Cristóbal; Soto L, Jorge

2011-07-01

The bioequivalence of different formulations of a same pharmaceutical product must be tested empirically. To evaluate the relative bioavailability for an oralformulation of mycophenolate mofetil (MMF) (Linfonex™) compared to the reference formulation (Cellcept™) to determine the bioequivalence between both formulations. A randomized, crossover, double-blind trial in 22 healthy male volunteers, who received a single oral dose of 1000 mg of Linfonex and Cellcept with a washout period of 10 days. Plasma levels of the drug were determined by high performance liquid chr ornatography. Plasma concentrations were plotted and maximum concentration, area under the plasma concentration versus time between 0 and 12 hours after administration and área under plasma concentration curve versus time after administration between 0 and infinity, were calculated for both products. The active compound, mycophenolic acid, was similarly absorbed in both formulations. No statistically significant differences were found in calculated pharmacokinetic parameters between both formulations. Linfonex™ 500 mg is bioequivalent to Cellcept™ 500 mg.

Visible-Light Organic Photocatalysis for Latent Radical-Initiated Polymerization via 2e–/1H+ Transfers: Initiation with Parallels to Photosynthesis

PubMed Central

2015-01-01

We report the latent production of free radicals from energy stored in a redox potential through a 2e–/1H+ transfer process, analogous to energy harvesting in photosynthesis, using visible-light organic photoredox catalysis (photocatalysis) of methylene blue chromophore with a sacrificial sterically hindered amine reductant and an onium salt oxidant. This enables light-initiated free-radical polymerization to continue over extended time intervals (hours) in the dark after brief (seconds) low-intensity illumination and beyond the spatial reach of light by diffusion of the metastable leuco-methylene blue photoproduct. The present organic photoredox catalysis system functions via a 2e–/1H+ shuttle mechanism, as opposed to the 1e– transfer process typical of organometallic-based and conventional organic multicomponent photoinitiator formulations. This prevents immediate formation of open-shell (radical) intermediates from the amine upon light absorption and enables the “storage” of light-energy without spontaneous initiation of the polymerization. Latent energy release and radical production are then controlled by the subsequent light-independent reaction (analogous to the Calvin cycle) between leuco-methylene blue and the onium salt oxidant that is responsible for regeneration of the organic methylene blue photocatalyst. This robust approach for photocatalysis-based energy harvesting and extended release in the dark enables temporally controlled redox initiation of polymer syntheses under low-intensity short exposure conditions and permits visible-light-mediated synthesis of polymers at least 1 order of magnitude thicker than achievable with conventional photoinitiated formulations and irradiation regimes. PMID:24786755

Visible-light organic photocatalysis for latent radical-initiated polymerization via 2e⁻/1H⁺ transfers: initiation with parallels to photosynthesis.

PubMed

Aguirre-Soto, Alan; Lim, Chern-Hooi; Hwang, Albert T; Musgrave, Charles B; Stansbury, Jeffrey W

2014-05-21

We report the latent production of free radicals from energy stored in a redox potential through a 2e(-)/1H(+) transfer process, analogous to energy harvesting in photosynthesis, using visible-light organic photoredox catalysis (photocatalysis) of methylene blue chromophore with a sacrificial sterically hindered amine reductant and an onium salt oxidant. This enables light-initiated free-radical polymerization to continue over extended time intervals (hours) in the dark after brief (seconds) low-intensity illumination and beyond the spatial reach of light by diffusion of the metastable leuco-methylene blue photoproduct. The present organic photoredox catalysis system functions via a 2e(-)/1H(+) shuttle mechanism, as opposed to the 1e(-) transfer process typical of organometallic-based and conventional organic multicomponent photoinitiator formulations. This prevents immediate formation of open-shell (radical) intermediates from the amine upon light absorption and enables the "storage" of light-energy without spontaneous initiation of the polymerization. Latent energy release and radical production are then controlled by the subsequent light-independent reaction (analogous to the Calvin cycle) between leuco-methylene blue and the onium salt oxidant that is responsible for regeneration of the organic methylene blue photocatalyst. This robust approach for photocatalysis-based energy harvesting and extended release in the dark enables temporally controlled redox initiation of polymer syntheses under low-intensity short exposure conditions and permits visible-light-mediated synthesis of polymers at least 1 order of magnitude thicker than achievable with conventional photoinitiated formulations and irradiation regimes.

Evolution of the transfer function characterization of surface scatter phenomena

NASA Astrophysics Data System (ADS)

Harvey, James E.; Pfisterer, Richard N.

2016-09-01

Based upon the empirical observation that BRDF measurements of smooth optical surfaces exhibited shift-invariant behavior when plotted versus    o , the original Harvey-Shack (OHS) surface scatter theory was developed as a scalar linear systems formulation in which scattered light behavior was characterized by a surface transfer function (STF) reminiscent of the optical transfer function (OTF) of modern image formation theory (1976). This shift-invariant behavior combined with the inverse power law behavior when plotting log BRDF versus log   o was quickly incorporated into several optical analysis software packages. Although there was no explicit smooth-surface approximation in the OHS theory, there was a limitation on both the incident and scattering angles. In 1988 the modified Harvey-Shack (MHS) theory removed the limitation on the angle of incidence; however, a moderate-angle scattering limitation remained. Clearly for large incident angles the BRDF was no longer shift-invariant as a different STF was now required for each incident angle. In 2011 the generalized Harvey-Shack (GHS) surface scatter theory, characterized by a two-parameter family of STFs, evolved into a practical modeling tool to calculate BRDFs from optical surface metrology data for situations that violate the smooth surface approximation inherent in the Rayleigh-Rice theory and/or the moderate-angle limitation of the Beckmann-Kirchhoff theory. And finally, the STF can be multiplied by the classical OTF to provide a complete linear systems formulation of image quality as degraded by diffraction, geometrical aberrations and surface scatter effects from residual optical fabrication errors.

Water pollutant fingerprinting tracks recent industrial transfer from coastal to inland China: A case study

PubMed Central

Zheng, Weiwei; Wang, Xia; Tian, Dajun; Jiang, Songhui; Andersen, Melvin E.; He, Genhsjeng; Crabbe, M. James C.; Zheng, Yuxin; Zhong, Yang; Qu, Weidong

2013-01-01

In recent years, China’s developed regions have transferred industries to undeveloped regions. Large numbers of unlicensed or unregistered enterprises are widespread in these undeveloped regions and they are subject to minimal regulation. Current methods for tracing industrial transfers in these areas, based on enterprise registration information or economic surveys, do not work. We have developed an analytical framework combining water fingerprinting and evolutionary analysis to trace the pollution transfer features between water sources. We collected samples in Eastern China (industrial export) and Central China (industrial acceptance) separately from two water systems. Based on the water pollutant fingerprints and evolutionary trees, we traced the pollution transfer associated with industrial transfer between the two areas. The results are consistent with four episodes of industrial transfers over the past decade. Our results also show likely types of the transferred industries - electronics, plastics, and biomedicines - that contribute to the water pollution transfer. PMID:23301152

Water pollutant fingerprinting tracks recent industrial transfer from coastal to inland China: A case study

NASA Astrophysics Data System (ADS)

Zheng, Weiwei; Wang, Xia; Tian, Dajun; Jiang, Songhui; Andersen, Melvin E.; He, Genhsjeng; Crabbe, M. James C.; Zheng, Yuxin; Zhong, Yang; Qu, Weidong

2013-01-01

In recent years, China's developed regions have transferred industries to undeveloped regions. Large numbers of unlicensed or unregistered enterprises are widespread in these undeveloped regions and they are subject to minimal regulation. Current methods for tracing industrial transfers in these areas, based on enterprise registration information or economic surveys, do not work. We have developed an analytical framework combining water fingerprinting and evolutionary analysis to trace the pollution transfer features between water sources. We collected samples in Eastern China (industrial export) and Central China (industrial acceptance) separately from two water systems. Based on the water pollutant fingerprints and evolutionary trees, we traced the pollution transfer associated with industrial transfer between the two areas. The results are consistent with four episodes of industrial transfers over the past decade. Our results also show likely types of the transferred industries - electronics, plastics, and biomedicines - that contribute to the water pollution transfer.

Improving Data Transfer Throughput with Direct Search Optimization

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

Balaprakash, Prasanna; Morozov, Vitali; Kettimuthu, Rajkumar

2016-01-01

Improving data transfer throughput over high-speed long-distance networks has become increasingly difficult. Numerous factors such as nondeterministic congestion, dynamics of the transfer protocol, and multiuser and multitask source and destination endpoints, as well as interactions among these factors, contribute to this difficulty. A promising approach to improving throughput consists in using parallel streams at the application layer.We formulate and solve the problem of choosing the number of such streams from a mathematical optimization perspective. We propose the use of direct search methods, a class of easy-to-implement and light-weight mathematical optimization algorithms, to improve the performance of data transfers by dynamicallymore » adapting the number of parallel streams in a manner that does not require domain expertise, instrumentation, analytical models, or historic data. We apply our method to transfers performed with the GridFTP protocol, and illustrate the effectiveness of the proposed algorithm when used within Globus, a state-of-the-art data transfer tool, on productionWAN links and servers. We show that when compared to user default settings our direct search methods can achieve up to 10x performance improvement under certain conditions. We also show that our method can overcome performance degradation due to external compute and network load on source end points, a common scenario at high performance computing facilities.« less

Variable-Domain Displacement Transfer Functions for Converting Surface Strains into Deflections for Structural Deformed Shape Predictions

NASA Technical Reports Server (NTRS)

Ko, William L.; Fleischer, Van Tran

2015-01-01

Variable-Domain Displacement Transfer Functions were formulated for shape predictions of complex wing structures, for which surface strain-sensing stations must be properly distributed to avoid jointed junctures, and must be increased in the high strain gradient region. Each embedded beam (depth-wise cross section of structure along a surface strain-sensing line) was discretized into small variable domains. Thus, the surface strain distribution can be described with a piecewise linear or a piecewise nonlinear function. Through discretization, the embedded beam curvature equation can be piece-wisely integrated to obtain the Variable-Domain Displacement Transfer Functions (for each embedded beam), which are expressed in terms of geometrical parameters of the embedded beam and the surface strains along the strain-sensing line. By inputting the surface strain data into the Displacement Transfer Functions, slopes and deflections along each embedded beam can be calculated for mapping out overall structural deformed shapes. A long tapered cantilever tubular beam was chosen for shape prediction analysis. The input surface strains were analytically generated from finite-element analysis. The shape prediction accuracies of the Variable- Domain Displacement Transfer Functions were then determined in light of the finite-element generated slopes and deflections, and were fofound to be comparable to the accuracies of the constant-domain Displacement Transfer Functions

Modified Displacement Transfer Functions for Deformed Shape Predictions of Slender Curved Structures with Varying Curvatives

NASA Technical Reports Server (NTRS)

Ko, William L.; Fleischer, Van Tran

2014-01-01

To eliminate the need to use finite-element modeling for structure shape predictions, a new method was invented. This method is to use the Displacement Transfer Functions to transform the measured surface strains into deflections for mapping out overall structural deformed shapes. The Displacement Transfer Functions are expressed in terms of rectilinearly distributed surface strains, and contain no material properties. This report is to apply the patented method to the shape predictions of non-symmetrically loaded slender curved structures with different curvatures up to a full circle. Because the measured surface strains are not available, finite-element analysis had to be used to analytically generate the surface strains. Previously formulated straight-beam Displacement Transfer Functions were modified by introducing the curvature-effect correction terms. Through single-point or dual-point collocations with finite-elementgenerated deflection curves, functional forms of the curvature-effect correction terms were empirically established. The resulting modified Displacement Transfer Functions can then provide quite accurate shape predictions. Also, the uniform straight-beam Displacement Transfer Function was applied to the shape predictions of a section-cut of a generic capsule (GC) outer curved sandwich wall. The resulting GC shape predictions are quite accurate in partial regions where the radius of curvature does not change sharply.

A Non-parametric Approach to Constrain the Transfer Function in Reverberation Mapping

NASA Astrophysics Data System (ADS)

Li, Yan-Rong; Wang, Jian-Min; Bai, Jin-Ming

2016-11-01

Broad emission lines of active galactic nuclei stem from a spatially extended region (broad-line region, BLR) that is composed of discrete clouds and photoionized by the central ionizing continuum. The temporal behaviors of these emission lines are blurred echoes of continuum variations (I.e., reverberation mapping, RM) and directly reflect the structures and kinematic information of BLRs through the so-called transfer function (also known as the velocity-delay map). Based on the previous works of Rybicki and Press and Zu et al., we develop an extended, non-parametric approach to determine the transfer function for RM data, in which the transfer function is expressed as a sum of a family of relatively displaced Gaussian response functions. Therefore, arbitrary shapes of transfer functions associated with complicated BLR geometry can be seamlessly included, enabling us to relax the presumption of a specified transfer function frequently adopted in previous studies and to let it be determined by observation data. We formulate our approach in a previously well-established framework that incorporates the statistical modeling of continuum variations as a damped random walk process and takes into account long-term secular variations which are irrelevant to RM signals. The application to RM data shows the fidelity of our approach.

Development of a self-emulsifying formulation that reduces the food effect for torcetrapib.

PubMed

Perlman, M E; Murdande, S B; Gumkowski, M J; Shah, T S; Rodricks, C M; Thornton-Manning, J; Freel, D; Erhart, L C

2008-03-03

Torcetrapib is a highly lipophilic (Clog P=7.45) and water insoluble cholesteryl ester transfer protein (CETP) inhibitor developed for the treatment of atherosclerosis. Self-emulsifying drug delivery system (SEDDS) formulations have been developed to reduce the food effect observed in early clinical trials using medium chain triglyceride (MCT) softgels and to increase the dose per capsule. MCT/Triacetin/Polysorbate 80/Capmul MCM (20/30/20/30) (MTPC) increased fasted exposure and thus reduced the food effect from 5- to 3-fold in dogs at a dose of 90 mg. Self-emulsifying formulations also accelerated absorption and generally decreased variability. Use of the lipophilic, GRAS cosolvent triacetin allowed a 2-fold increase in the dose per capsule. For the three formulations evaluated in dogs that showed significant differences in absorption, emulsion droplet size did not appear to play a significant role. Absorption did increase with Cremophor RH40 content, and at 50% Cremophor RH40 there was no food effect (at 30 mg). High polar surfactant content also resulted in poor dose proportionality, while there was good dose proportionality for MTPC. Studies of in vitro lipolysis are being conducted to aid in understanding the in vitro/in vivo relationships for torcetrapib SEDDS absorption.

Combining Interactive Infrastructure Modeling and Evolutionary Algorithm Optimization for Sustainable Water Resources Design

NASA Astrophysics Data System (ADS)

Smith, R.; Kasprzyk, J. R.; Zagona, E. A.

2013-12-01

Population growth and climate change, combined with difficulties in building new infrastructure, motivate portfolio-based solutions to ensuring sufficient water supply. Powerful simulation models with graphical user interfaces (GUI) are often used to evaluate infrastructure portfolios; these GUI based models require manual modification of the system parameters, such as reservoir operation rules, water transfer schemes, or system capacities. Multiobjective evolutionary algorithm (MOEA) based optimization can be employed to balance multiple objectives and automatically suggest designs for infrastructure systems, but MOEA based decision support typically uses a fixed problem formulation (i.e., a single set of objectives, decisions, and constraints). This presentation suggests a dynamic framework for linking GUI-based infrastructure models with MOEA search. The framework begins with an initial formulation which is solved using a MOEA. Then, stakeholders can interact with candidate solutions, viewing their properties in the GUI model. This is followed by changes in the formulation which represent users' evolving understanding of exigent system properties. Our case study is built using RiverWare, an object-oriented, data-centered model that facilitates the representation of a diverse array of water resources systems. Results suggest that assumptions within the initial MOEA search are violated after investigating tradeoffs and reveal how formulations should be modified to better capture stakeholders' preferences.

The missing piece in the puzzle: Prediction of aggregation via the protein-protein interaction parameter A∗2.

PubMed

Koepf, Ellen; Schroeder, Rudolf; Brezesinski, Gerald; Friess, Wolfgang

2018-07-01

The tendency of protein pharmaceuticals to form aggregates is a major challenge during formulation development, as aggregation affects quality and safety of the product. In particular, the formation of large native-like particles in the context of liquid-air interfacial stress is a well-known but not fully understood problem. Focusing on the two most fundamental criteria of protein formulation affecting protein-protein interaction, the impact of pH and ionic strength on the interaction parameter A ∗ 2 and its link to aggregation upon mechanical stress was investigated. A ∗ 2 of two monoclonal antibodies (mABs) and a polyclonal IgG was determined using dynamic light scattering and was correlated to the number of particles formed upon shaking in vials analyzed by visual inspection, turbidity analysis, light obscuration and micro-flow imaging. A good correlation between aggregation induced by interfacial stress and formulation pH was given. It could be shown that A ∗ 2 was highest for mAB 1 and lowest for IgG, what was in good accordance with the number of particles formed. Shaking of IgG resulted in overall higher numbers of particles compared to the two mABs. A ∗ 2 decreased and particle numbers increased with increasing pH. Different to pH, ionic strength only slightly affected A ∗ 2 . Nevertheless, at high ionic (100 mM) strength the samples exhibited more pronounced particle formation, particularly of large particles >25 µm, which was most pronounced at high pH. Protein solutions were identified to form continuous films with an inhomogeneous protein distribution at the liquid-air interface. These areas of agglomerated, native-like protein material can be transferred into the bulk solution by compression-decompression of the interface. Whether or not those clusters lead to the appearance of large protein aggregates or fall apart depends on the attractive or repulsive forces between protein molecules. Thus, protein aggregation due to interfacial stress is correlated with the protein-protein interactions as determined by A ∗ 2 . This enables to differentiate different antibodies according to their propensity to form particles upon mechanical stress and to identify optimum formulation conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Specialized CCDs for high-frame-rate visible imaging and UV imaging applications

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Taylor, Gordon C.; Shallcross, Frank V.; Tower, John R.; Lawler, William B.; Harrison, Lorna J.; Socker, Dennis G.; Marchywka, Mike

1993-11-01

This paper reports recent progress by the authors in two distinct charge coupled device (CCD) technology areas. The first technology area is high frame rate, multi-port, frame transfer imagers. A 16-port, 512 X 512, split frame transfer imager and a 32-port, 1024 X 1024, split frame transfer imager are described. The thinned, backside illuminated devices feature on-chip correlated double sampling, buried blooming drains, and a room temperature dark current of less than 50 pA/cm2, without surface accumulation. The second technology area is vacuum ultraviolet (UV) frame transfer imagers. A developmental 1024 X 640 frame transfer imager with 20% quantum efficiency at 140 nm is described. The device is fabricated in a p-channel CCD process, thinned for backside illumination, and utilizes special packaging to achieve stable UV response.

[Design of a risk matrix to assess sterile formulations at health care facilities].

PubMed

Martín de Rosales Cabrera, A M; López Cabezas, C; García Salom, P

2014-05-01

To design a matrix allowing classifying sterile formulations prepared at the hospital with different risk levels. i) Literature search and critical appraisal of the model proposed by the European Resolution CM/Res Ap(2011)1, ii) Identification of the risk associated to the elaboration process by means of the AMFE methodology (Modal Analysis of Failures and Effects), iii) estimation of the severity associated to the risks detected. After initially trying a model of numeric scoring, the classification matrix was changed to an alphabetical classification, grading each criterion from A to D.Each preparation assessed is given a 6-letter combination with three possible risk levels: low, intermediate, and high. This model was easier for risk assignment, and more reproducible. The final model designed analyzes 6 criteria: formulation process, administration route, the drug's safety profile, amount prepared, distribution, and susceptibility for microbiological contamination.The risk level obtained will condition the requirements of the formulation area, validity time, and storing conditions. The matrix model proposed may help health care institutions to better assess the risk of sterile formulations prepared,and provides information about the acceptable validity time according to the storing conditions and the manufacturing area. Its use will increase the safety level of this procedure as well as help in resources planning and distribution. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Triatomicidal effect of new spot-on formulations applied to poultry in semi-field conditions.

PubMed

Juan, Laura W; Seccacini, Emilia A; Zerba, Eduardo N; Canale, Delmi; Alzogaray, Raúl A

2013-01-01

Chagas disease is an endemic disease affecting ten million people in the American continent. Produced by a parasite transmitted by triatomine insects, the main actions for reducing the incidence of this disease are focused on the control of insect vectors. This type of control has produced highly effective results within rural homes, but not in peridomestic areas (kitchens, warehouses, hen houses and other buildings not attached to the houses). The object of the present study was to assess the triatomicidal effect of new spot-on formulations developed by our laboratory in a semi-rural environment. The active ingredients of the formulations were β-cypermethrin, pyriproxyfen, or β-cypermethrin + pyriproxyfen. All formulations were applied to hens and tested in miniature replicas of rural households where experimental populations of Triatoma infestans, the main vector of Chagas disease in Argentina, had been previously released. The experimental populations exposed to formulations containing β-cypermethrin or β-cypermethrin + pyriproxyfen were noticeably reduced compared to non-treated control groups. However, no differences were observed between the effects produced by β-cypermethrin alone and β-cypermethrin + pyriproxyfen. Pyriproxyfen alone produced no significant reduction in the experimental populations of T. infestans. These results suggest that spot-on application of β-cypermethrin could be a useful complementary tool for controlling triatomine insects in the peridomestic areas of rural homes.

Transfers between libration-point orbits in the elliptic restricted problem

NASA Astrophysics Data System (ADS)

Hiday-Johnston, L. A.; Howell, K. C.

1994-04-01

A strategy is formulated to design optimal time-fixed impulsive transfers between three-dimensional libration-point orbits in the vicinity of the interior L1 libration point of the Sun-Earth/Moon barycenter system. The adjoint equation in terms of rotating coordinates in the elliptic restricted three-body problem is shown to be of a distinctly different form from that obtained in the analysis of trajectories in the two-body problem. Also, the necessary conditions for a time-fixed two-impulse transfer to be optimal are stated in terms of the primer vector. Primer vector theory is then extended to nonoptimal impulsive trajectories in order to establish a criterion whereby the addition of an interior impulse reduces total fuel expenditure. The necessary conditions for the local optimality of a transfer containing additional impulses are satisfied by requiring continuity of the Hamiltonian and the derivative of the primer vector at all interior impulses. Determination of location, orientation, and magnitude of each additional impulse is accomplished by the unconstrained minimization of the cost function using a multivariable search method. Results indicate that substantial savings in fuel can be achieved by the addition of interior impulsive maneuvers on transfers between libration-point orbits.

A molecular study of microbe transfer between distant environments.

PubMed

Hooper, Sean D; Raes, Jeroen; Foerstner, Konrad U; Harrington, Eoghan D; Dalevi, Daniel; Bork, Peer

2008-07-09

Environments and their organic content are generally not static and isolated, but in a constant state of exchange and interaction with each other. Through physical or biological processes, organisms, especially microbes, may be transferred between environments whose characteristics may be quite different. The transferred microbes may not survive in their new environment, but their DNA will be deposited. In this study, we compare two environmental sequencing projects to find molecular evidence of transfer of microbes over vast geographical distances. By studying synonymous nucleotide composition, oligomer frequency and orthology between predicted genes in metagenomics data from two environments, terrestrial and aquatic, and by correlating with phylogenetic mappings, we find that both environments are likely to contain trace amounts of microbes which have been far removed from their original habitat. We also suggest a bias in direction from soil to sea, which is consistent with the cycles of planetary wind and water. Our findings support the Baas-Becking hypothesis formulated in 1934, which states that due to dispersion and population sizes, microbes are likely to be found in widely disparate environments. Furthermore, the availability of genetic material from distant environments is a possible font of novel gene functions for lateral gene transfer.

A Molecular Study of Microbe Transfer between Distant Environments

PubMed Central

Hooper, Sean D.; Raes, Jeroen; Foerstner, Konrad U.; Harrington, Eoghan D.; Dalevi, Daniel; Bork, Peer

2008-01-01

Background Environments and their organic content are generally not static and isolated, but in a constant state of exchange and interaction with each other. Through physical or biological processes, organisms, especially microbes, may be transferred between environments whose characteristics may be quite different. The transferred microbes may not survive in their new environment, but their DNA will be deposited. In this study, we compare two environmental sequencing projects to find molecular evidence of transfer of microbes over vast geographical distances. Methodology By studying synonymous nucleotide composition, oligomer frequency and orthology between predicted genes in metagenomics data from two environments, terrestrial and aquatic, and by correlating with phylogenetic mappings, we find that both environments are likely to contain trace amounts of microbes which have been far removed from their original habitat. We also suggest a bias in direction from soil to sea, which is consistent with the cycles of planetary wind and water. Conclusions Our findings support the Baas-Becking hypothesis formulated in 1934, which states that due to dispersion and population sizes, microbes are likely to be found in widely disparate environments. Furthermore, the availability of genetic material from distant environments is a possible font of novel gene functions for lateral gene transfer. PMID:18612393

Estimation of Handling Qualities Parameters of the Tu-144 Supersonic Transport Aircraft from Flight Test Data

NASA Technical Reports Server (NTRS)

Curry, Timothy J.; Batterson, James G. (Technical Monitor)

2000-01-01

Low order equivalent system (LOES) models for the Tu-144 supersonic transport aircraft were identified from flight test data. The mathematical models were given in terms of transfer functions with a time delay by the military standard MIL-STD-1797A, "Flying Qualities of Piloted Aircraft," and the handling qualities were predicted from the estimated transfer function coefficients. The coefficients and the time delay in the transfer functions were estimated using a nonlinear equation error formulation in the frequency domain. Flight test data from pitch, roll, and yaw frequency sweeps at various flight conditions were used for parameter estimation. Flight test results are presented in terms of the estimated parameter values, their standard errors, and output fits in the time domain. Data from doublet maneuvers at the same flight conditions were used to assess the predictive capabilities of the identified models. The identified transfer function models fit the measured data well and demonstrated good prediction capabilities. The Tu-144 was predicted to be between level 2 and 3 for all longitudinal maneuvers and level I for all lateral maneuvers. High estimates of the equivalent time delay in the transfer function model caused the poor longitudinal rating.

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

Li, Yan-Rong; Wang, Jian-Min; Bai, Jin-Ming, E-mail: liyanrong@mail.ihep.ac.cn

Broad emission lines of active galactic nuclei stem from a spatially extended region (broad-line region, BLR) that is composed of discrete clouds and photoionized by the central ionizing continuum. The temporal behaviors of these emission lines are blurred echoes of continuum variations (i.e., reverberation mapping, RM) and directly reflect the structures and kinematic information of BLRs through the so-called transfer function (also known as the velocity-delay map). Based on the previous works of Rybicki and Press and Zu et al., we develop an extended, non-parametric approach to determine the transfer function for RM data, in which the transfer function ismore » expressed as a sum of a family of relatively displaced Gaussian response functions. Therefore, arbitrary shapes of transfer functions associated with complicated BLR geometry can be seamlessly included, enabling us to relax the presumption of a specified transfer function frequently adopted in previous studies and to let it be determined by observation data. We formulate our approach in a previously well-established framework that incorporates the statistical modeling of continuum variations as a damped random walk process and takes into account long-term secular variations which are irrelevant to RM signals. The application to RM data shows the fidelity of our approach.« less

Application of Artificial Neural Networks in the Design and Optimization of a Nanoparticulate Fingolimod Delivery System Based on Biodegradable Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate).

PubMed

Shahsavari, Shadab; Rezaie Shirmard, Leila; Amini, Mohsen; Abedin Dokoosh, Farid

2017-01-01

Formulation of a nanoparticulate Fingolimod delivery system based on biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) was optimized according to artificial neural networks (ANNs). Concentration of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PVA and amount of Fingolimod is considered as the input value, and the particle size, polydispersity index, loading capacity, and entrapment efficacy as output data in experimental design study. In vitro release study was carried out for best formulation according to statistical analysis. ANNs are employed to generate the best model to determine the relationships between various values. In order to specify the model with the best accuracy and proficiency for the in vitro release, a multilayer percepteron with different training algorithm has been examined. Three training model formulations including Levenberg-Marquardt (LM), gradient descent, and Bayesian regularization were employed for training the ANN models. It is demonstrated that the predictive ability of each training algorithm is in the order of LM > gradient descent > Bayesian regularization. Also, optimum formulation was achieved by LM training function with 15 hidden layers and 20 neurons. The transfer function of the hidden layer for this formulation and the output layer were tansig and purlin, respectively. Also, the optimization process was developed by minimizing the error among the predicted and observed values of training algorithm (about 0.0341). Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Influenza vaccine production for Brazil: a classic example of successful North-South bilateral technology transfer.

PubMed

Miyaki, Cosue; Meros, Mauricio; Precioso, Alexander R; Raw, Isaias

2011-07-01

Technology transfer is a promising approach to increase vaccine production at an affordable price in developing countries. In the case of influenza, it is imperative that developing countries acquire the technology to produce pandemic vaccines through the transfer of know-how, as this will be the only way for the majority of these countries to face the huge demand for vaccine created by influenza pandemics. Access to domestically produced influenza vaccine in such health crises is thus an important national defence strategy. However, technology transfer is not a simple undertaking. It requires a committed provider who is willing to transfer a complete production process, and not just the formulation and fill-finish parts of the process. It requires a recipient with established experience in vaccine production for human use and the ability to conduct research into new developments. In addition, the country of the recipient should preferably have sufficient financial resources to support the undertaking, and an internal market for the new vaccine. Technology transfer should create a solid partnership that results in the joint development of new competency, improvements to the product, and to further innovation. The Instituto Butantan-sanofi pasteur partnership can be seen as a model for successful technology transfer and has led to the technological independence of the Instituto Butantan in the use a strategic public health tool. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cloud-generated radiative heating and its generation of available potential energy

NASA Technical Reports Server (NTRS)

Stuhlmann, R.; Smith, G. L.

1989-01-01

The generation of zonal available potential energy (APE) by cloud radiative heating is discussed. The APE concept was mathematically formulated by Lorenz (1955) as a measure of the maximum amount of total potential energy that is available for conversion by adiabatic processes to kinetic energy. The rate of change of APE is the rate of the generation of APE minus the rate of conversion between potential and kinetic energy. By radiative transfer calculations, a mean cloud-generated radiative heating for a well defined set of cloud classes is derived as a function of cloud optical thickness. The formulation is suitable for using a general cloud parameter data set and has the advantage of taking into account nonlinearities between the microphysical and macrophysical cloud properties and the related radiation field.

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

Stubos, A.K.; Caseiras, C.P.; Buchlin, J.M.

The transient two-phase flow and phase change heat transfer processes in porous media are investigated. Based on an enthalpic approach, a one-domain formulation of the problem is developed, avoiding explicit internal boundary tracking between single- and two-phase regions. An efficient numerical scheme is applied to obtain the solution on a fixed two-dimensional grid. The transient response of a liquid-saturated, self-heated porous bed is examined in detail. A physical interpretation of a liquid-saturated, self-heated porous bed is examined in detail. A physical interpretation of the computed response to fast power transients is attempted. Comparisons with experimental data are made regarding themore » average void fraction and the limiting dryout heat flux. The numerical approach is extended, keeping the one-domain formulation, to include the surrounding wall structure in the calculation.« less

Natural and synthetic polymers in fabric and home care applications

NASA Astrophysics Data System (ADS)

Paderes, Monissa; Ahirwal, Deepak; Fernández Prieto, Susana

2017-07-01

Polymers can be tailored to provide different benefits in Fabric & Home Care formulations depending on the monomers and modifications used, such as avoiding dye transfer inhibition in the wash, modifying the surface of tiles or increasing the viscosity and providing suspension properties to consumer products. Specifically, the rheology modification properties of synthetic and natural polymers are discussed in this chapter. The choice of a polymeric rheology modifier will depend on the formulation ingredients (charges, functional groups), the type and the amount of surfactants, the pH and the desired rheology modification. Natural polymeric rheology modifiers have been traditionally used in the food industry, being xanthan gum one of the most well-known ones. On the contrary, synthetic rheology modifiers are preferably used in paints & coats, textile printing and cleaning products.

Suppression of the sonic heat transfer limit in high-temperature heat pipes

NASA Astrophysics Data System (ADS)

Dobran, Flavio

1989-08-01

The design of high-performance heat pipes requires optimization of heat transfer surfaces and liquid and vapor flow channels to suppress the heat transfer operating limits. In the paper an analytical model of the vapor flow in high-temperature heat pipes is presented, showing that the axial heat transport capacity limited by the sonic heat transfer limit depends on the working fluid, vapor flow area, manner of liquid evaporation into the vapor core of the evaporator, and lengths of the evaporator and adiabatic regions. Limited comparisons of the model predictions with data of the sonic heat transfer limits are shown to be very reasonable, giving credibility to the proposed analytical approach to determine the effect of various parameters on the axial heat transport capacity. Large axial heat transfer rates can be achieved with large vapor flow cross-sectional areas, small lengths of evaporator and adiabatic regions or a vapor flow area increase in these regions, and liquid evaporation in the evaporator normal to the main flow.

Breakdown of local information processing may underlie isoflurane anesthesia effects.

PubMed

Wollstadt, Patricia; Sellers, Kristin K; Rudelt, Lucas; Priesemann, Viola; Hutt, Axel; Fröhlich, Flavio; Wibral, Michael

2017-06-01

The disruption of coupling between brain areas has been suggested as the mechanism underlying loss of consciousness in anesthesia. This hypothesis has been tested previously by measuring the information transfer between brain areas, and by taking reduced information transfer as a proxy for decoupling. Yet, information transfer is a function of the amount of information available in the information source-such that transfer decreases even for unchanged coupling when less source information is available. Therefore, we reconsidered past interpretations of reduced information transfer as a sign of decoupling, and asked whether impaired local information processing leads to a loss of information transfer. An important prediction of this alternative hypothesis is that changes in locally available information (signal entropy) should be at least as pronounced as changes in information transfer. We tested this prediction by recording local field potentials in two ferrets after administration of isoflurane in concentrations of 0.0%, 0.5%, and 1.0%. We found strong decreases in the source entropy under isoflurane in area V1 and the prefrontal cortex (PFC)-as predicted by our alternative hypothesis. The decrease in source entropy was stronger in PFC compared to V1. Information transfer between V1 and PFC was reduced bidirectionally, but with a stronger decrease from PFC to V1. This links the stronger decrease in information transfer to the stronger decrease in source entropy-suggesting reduced source entropy reduces information transfer. This conclusion fits the observation that the synaptic targets of isoflurane are located in local cortical circuits rather than on the synapses formed by interareal axonal projections. Thus, changes in information transfer under isoflurane seem to be a consequence of changes in local processing more than of decoupling between brain areas. We suggest that source entropy changes must be considered whenever interpreting changes in information transfer as decoupling.

Breakdown of local information processing may underlie isoflurane anesthesia effects

PubMed Central

Sellers, Kristin K.; Priesemann, Viola; Hutt, Axel

2017-01-01

The disruption of coupling between brain areas has been suggested as the mechanism underlying loss of consciousness in anesthesia. This hypothesis has been tested previously by measuring the information transfer between brain areas, and by taking reduced information transfer as a proxy for decoupling. Yet, information transfer is a function of the amount of information available in the information source—such that transfer decreases even for unchanged coupling when less source information is available. Therefore, we reconsidered past interpretations of reduced information transfer as a sign of decoupling, and asked whether impaired local information processing leads to a loss of information transfer. An important prediction of this alternative hypothesis is that changes in locally available information (signal entropy) should be at least as pronounced as changes in information transfer. We tested this prediction by recording local field potentials in two ferrets after administration of isoflurane in concentrations of 0.0%, 0.5%, and 1.0%. We found strong decreases in the source entropy under isoflurane in area V1 and the prefrontal cortex (PFC)—as predicted by our alternative hypothesis. The decrease in source entropy was stronger in PFC compared to V1. Information transfer between V1 and PFC was reduced bidirectionally, but with a stronger decrease from PFC to V1. This links the stronger decrease in information transfer to the stronger decrease in source entropy—suggesting reduced source entropy reduces information transfer. This conclusion fits the observation that the synaptic targets of isoflurane are located in local cortical circuits rather than on the synapses formed by interareal axonal projections. Thus, changes in information transfer under isoflurane seem to be a consequence of changes in local processing more than of decoupling between brain areas. We suggest that source entropy changes must be considered whenever interpreting changes in information transfer as decoupling. PMID:28570661

Hatch assembly

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

Marshall, J.R.; Hardin, R.T. Jr.

1987-07-07

This patent describes a nuclear reactor installation including means defining a fuel handling area and means defining a containment area separated from the fuel handling area and including a refuelling cavity; the improvement comprising: (a) a fuel transfer tube connecting the refuelling cavity with the fuel handling area; the fuel transfer tube having a first end in the fuel handling area and a second end in the refueling cavity; (b) valve means for opening and closing the first end; and (c) a hatch assembly mounted on the second end; the hatch assembly including (1) a hatch ring affixed to themore » fuel transfer tube at the second end the hatch ring has an integral annular seat surrounded by the hatch ring and defines a hatch opening in the second end of the fuel transfer tube; (2) a hatch cover adapts to be positioned on the annular seat for covering the hatch opening; (3) latching units are supported on the hatch ring about the hatch opening, each latching unit.« less

Entropy Transfer between Residue Pairs and Allostery in Proteins: Quantifying Allosteric Communication in Ubiquitin.

PubMed

Hacisuleyman, Aysima; Erman, Burak

2017-01-01

It has recently been proposed by Gunasakaran et al. that allostery may be an intrinsic property of all proteins. Here, we develop a computational method that can determine and quantify allosteric activity in any given protein. Based on Schreiber's transfer entropy formulation, our approach leads to an information transfer landscape for the protein that shows the presence of entropy sinks and sources and explains how pairs of residues communicate with each other using entropy transfer. The model can identify the residues that drive the fluctuations of others. We apply the model to Ubiquitin, whose allosteric activity has not been emphasized until recently, and show that there are indeed systematic pathways of entropy and information transfer between residues that correlate well with the activities of the protein. We use 600 nanosecond molecular dynamics trajectories for Ubiquitin and its complex with human polymerase iota and evaluate entropy transfer between all pairs of residues of Ubiquitin and quantify the binding susceptibility changes upon complex formation. We explain the complex formation propensities of Ubiquitin in terms of entropy transfer. Important residues taking part in allosteric communication in Ubiquitin predicted by our approach are in agreement with results of NMR relaxation dispersion experiments. Finally, we show that time delayed correlation of fluctuations of two interacting residues possesses an intrinsic causality that tells which residue controls the interaction and which one is controlled. Our work shows that time delayed correlations, entropy transfer and causality are the required new concepts for explaining allosteric communication in proteins.

Physical Education Teachers in Motion: An Account of Attrition and Area Transfer

ERIC Educational Resources Information Center

Mäkelä, Kasper; Hirvensalo, Mirja; Laakso, Lauri; Whipp, Peter R.

2014-01-01

Background: Teacher turnover has been identified as a major problem that represents instability in teaching. Teacher turnover can be divided into three components: attrition means that the teacher is leaving the profession; "area transfer" means that the teacher is changing his/her subject area and "migration" means that the…

Robotic technology evolution and transfer

NASA Technical Reports Server (NTRS)

Marzwell, Neville I.

1992-01-01

A report concerning technology transfer in the area of robotics is presented in vugraph form. The following topics are discussed: definition of technology innovation and tech-transfer; concepts relevant for understanding tech-transfer; models advanced to portray tech-transfer process; factors identified as promoting tech-transfer; factors identified as impeding tech-transfer; what important roles do individuals fulfill in tech-transfer; federal infrastructure for promoting tech-transfer; federal infrastructure for promoting tech-transfer; robotic technology evolution; robotic technology transferred; and recommendations for successful robotics tech-transfer.

Randomized clinical efficacy of superficial peeling with 85% lactic acid versus 70% glycolic acid*

PubMed Central

Prestes, Paula Souza; de Oliveira, Márcia Motta Maia; Leonardi, Gislaine Ricci

2013-01-01

BACKGROUND: Peeling is a procedure which aims to accelerate the process of skin exfoliation. OBJECTIVES Development of formulations containing lactic acid at 85% or glycolic acid at 70% and the evaluation of these formulations on clinical efficacy in reduction of fine wrinkles. METHODS Preliminary stability tests were carried out and an in vivo study was performed with three groups with 9 representatives each. One was the control group, which used only sunscreen; another one used lactic acid+sunscreen, and the last group used acid glycolic+sunscreen. Clinical efficacy was assessed with a CCD color microscope, through the digitization of images before and after treatment. The applications were carried out by a dermatologist, once a mont h every 30 days, during 3 months. The area with wrinkles was calculated by planimetry point counting, in accordance with Mandarin-de-Lacerda. RESULTS The formulations were stable in the visual and Ph evaluation. There was no improvement in the control group; for lactic acid, there was significant improvement after the second peeling application on the outer lateral area of the right eye and after the third application on the outer lateral area of the left eye. For the glycolic acid group, there was significant improvement in the outer lateral area of the left eye after the first application, and of the right eye region, after three applications. The formulations used must be kept under refrigeration and should be manipulated every 30 days. CONCLUSIONS Both peelings were effective in reducing fine wrinkles of the outer lateral eye area after three applications (p≤0.05%). It was observed that peeling efficacy in the external-lateral region of one eye might be different compared with that in skin of the external-lateral region of the other eye, relative to the speed of skin improvement. PMID:24474097

Arms Transfers to Venezuela: A Comparative and Critical Analysis of the Acquisition Process (1980-1996).

DTIC Science & Technology

1999-03-01

Budget (Oficina Central de Presupuesto [OCEPRE]), which is the presidential agency with overall responsibility to formulate the national budget...Budget (Oficina Central de Presupuesto OCEPRE), and they receive a special treatment in the Venezuelan Budgetary process. The OCEPRE is the...the Central Office of Budget (Oficina Central de Presupuesto , OCEPRE). This occurs when funds for weapons acquisitions come from the ordinary budget

Quantum Engineering of Dynamical Gauge Fields on Optical Lattices

DTIC Science & Technology

2016-07-08

opens the door for exciting new research directions, such as quantum simulation of the Schwinger model and of non-Abelian models. (a) Papers...exact blocking formulas from the TRG formulation of the transfer matrix. The second is a worm algorithm. The particle number distributions obtained...a fact that can be explained by an approximate particle- hole symmetry. We have also developed a computer code suite for simulating the Abelian

Immune-based therapies.

PubMed

Lein, B

1995-12-01

Several immune-based HIV therapy studies presented at the Interscience Conference on Antimicrobial Agents Chemotherapy (ICAAC) are summarized. These studies involve the following therapies: HIV-IT, a gene therapy approach to augmenting the body's anti-HIV responses; interferon-alpha n3, a new formulation of alpha interferon with fewer toxicities; transfer of immune responses from one individual to another, also called passive immune therapy; and interleukin-2 (IL-2) in combination with protease inhibitors.

The application of remote sensing to the development and formulation of hydrologic planning models

NASA Technical Reports Server (NTRS)

Fowler, T. R.; Castruccio, P. A.; Loats, H. L., Jr.

1977-01-01

The development of a remote sensing model and its efficiency in determining parameters of hydrologic models are reviewed. Procedures for extracting hydrologic data from LANDSAT imagery, and the visual analysis of composite imagery are presented. A hydrologic planning model is developed and applied to determine seasonal variations in watershed conditions. The transfer of this technology to a user community and contract arrangements are discussed.

Diffusion relaxation times of nonequilibrium isolated small bodies and their solid phase ensembles to equilibrium states

NASA Astrophysics Data System (ADS)

Tovbin, Yu. K.

2017-08-01

The possibility of obtaining analytical estimates in a diffusion approximation of the times needed by nonequilibrium small bodies to relax to their equilibrium states based on knowledge of the mass transfer coefficient is considered. This coefficient is expressed as the product of the self-diffusion coefficient and the thermodynamic factor. A set of equations for the diffusion transport of mixture components is formulated, characteristic scales of the size of microheterogeneous phases are identified, and effective mass transfer coefficients are constructed for them. Allowing for the developed interface of coexisting and immiscible phases along with the porosity of solid phases is discussed. This approach can be applied to the diffusion equalization of concentrations of solid mixture components in many physicochemical systems: the mutual diffusion of components in multicomponent systems (alloys, semiconductors, solid mixtures of inert gases) and the mass transfer of an absorbed mobile component in the voids of a matrix consisting of slow components or a mixed composition of mobile and slow components (e.g., hydrogen in metals, oxygen in oxides, and the transfer of molecules through membranes of different natures, including polymeric).

Research utilization in the building industry: decision model and preliminary assessment

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

Watts, R.L.; Johnson, D.R.; Smith, S.A.

1985-10-01

The Research Utilization Program was conceived as a far-reaching means for managing the interactions of the private sector and the federal research sector as they deal with energy conservation in buildings. The program emphasizes a private-public partnership in planning a research agenda and in applying the results of ongoing and completed research. The results of this task support the hypothesis that the transfer of R and D results to the buildings industry can be accomplished more efficiently and quickly by a systematic approach to technology transfer. This systematic approach involves targeting decision makers, assessing research and information needs, properly formatingmore » information, and then transmitting the information through trusted channels. The purpose of this report is to introduce elements of a market-oriented knowledge base, which would be useful to the Building Systems Division, the Office of Buildings and Community Systems and their associated laboratories in managing a private-public research partnership on a rational systematic basis. This report presents conceptual models and data bases that can be used in formulating a technology transfer strategy and in planning technology transfer programs.« less

Quantum Jarzynski equality of measurement-based work extraction

NASA Astrophysics Data System (ADS)

Morikuni, Yohei; Tajima, Hiroyasu; Hatano, Naomichi

2017-03-01

Many studies of quantum-size heat engines assume that the dynamics of an internal system is unitary and that the extracted work is equal to the energy loss of the internal system. Both assumptions, however, should be under scrutiny. In the present paper, we analyze quantum-scale heat engines, employing the measurement-based formulation of the work extraction recently introduced by Hayashi and Tajima [M. Hayashi and H. Tajima, arXiv:1504.06150]. We first demonstrate the inappropriateness of the unitary time evolution of the internal system (namely, the first assumption above) using a simple two-level system; we show that the variance of the energy transferred to an external system diverges when the dynamics of the internal system is approximated to a unitary time evolution. Second, we derive the quantum Jarzynski equality based on the formulation of Hayashi and Tajima as a relation for the work measured by an external macroscopic apparatus. The right-hand side of the equality reduces to unity for "natural" cyclic processes but fluctuates wildly for noncyclic ones, exceeding unity often. This fluctuation should be detectable in experiments and provide evidence for the present formulation.

Multifunctional Nanoplatforms for Fluorescence Imaging and Photodynamic Therapy Developed by Post-loading Photosensitizer and Fluorophore to Polyacrylamide Nanoparticles

PubMed Central

Gupta, Anurag; Wang, Shouyan; Pera, Paula; Rao, K.V.R.; Patel, Nayan; Ohulchanskyy, Tymish Y.; Missert, Joseph; Morgan, Janet; Koo-Lee, Yong-Eun; Kopelman, Raoul; Pandey, Ravindra K.

2011-01-01

We report a novel post-loading approach for constructing a multifunctional biodegradable polyacrylamide (PAA) nanoplatform for tumor-imaging (fluorescence) and photodynamic therapy (PDT). This approach provides an opportunity to post-load the imaging and therapeutic agents at desired concentrations. Among the PAA nanoparticles, a formulation containing the photosensitizer, HPPH [3-(1’-hexyloxyethyl)pyropheophorbide-a], and the cyanine dye in a ratio of 2:1 minimized the undesirable quenching of the HPPH electronic excitation energy due to energy migration within the nanoparticles and/or Förster (fluorescence) resonance energy transfer (FRET) between HPPH and cyanine dye. An excellent tumor-imaging (NIR fluorescence) and phototherapeutic efficacy of the nanoconstruct formulation is demonstrated. Under similar treatment parameters the HPPH in 1% Tween 80/5% aqueous dextrose formulation was less effective than the nanoconstruct containing HPPH and cyanine dye in a ratio of 2 to 1. This is the first example showing the utility of the post-loading approach in developing a nanoconstructs for tumor-imaging and therapy. PMID:22115602

Quantum Jarzynski equality of measurement-based work extraction.

PubMed

Morikuni, Yohei; Tajima, Hiroyasu; Hatano, Naomichi

2017-03-01

Many studies of quantum-size heat engines assume that the dynamics of an internal system is unitary and that the extracted work is equal to the energy loss of the internal system. Both assumptions, however, should be under scrutiny. In the present paper, we analyze quantum-scale heat engines, employing the measurement-based formulation of the work extraction recently introduced by Hayashi and Tajima [M. Hayashi and H. Tajima, arXiv:1504.06150]. We first demonstrate the inappropriateness of the unitary time evolution of the internal system (namely, the first assumption above) using a simple two-level system; we show that the variance of the energy transferred to an external system diverges when the dynamics of the internal system is approximated to a unitary time evolution. Second, we derive the quantum Jarzynski equality based on the formulation of Hayashi and Tajima as a relation for the work measured by an external macroscopic apparatus. The right-hand side of the equality reduces to unity for "natural" cyclic processes but fluctuates wildly for noncyclic ones, exceeding unity often. This fluctuation should be detectable in experiments and provide evidence for the present formulation.

A methodology for formulating a minimal uncertainty model for robust control system design and analysis

NASA Technical Reports Server (NTRS)

Belcastro, Christine M.; Chang, B.-C.; Fischl, Robert

1989-01-01

In the design and analysis of robust control systems for uncertain plants, the technique of formulating what is termed an M-delta model has become widely accepted and applied in the robust control literature. The M represents the transfer function matrix M(s) of the nominal system, and delta represents an uncertainty matrix acting on M(s). The uncertainty can arise from various sources, such as structured uncertainty from parameter variations or multiple unstructured uncertainties from unmodeled dynamics and other neglected phenomena. In general, delta is a block diagonal matrix, and for real parameter variations the diagonal elements are real. As stated in the literature, this structure can always be formed for any linear interconnection of inputs, outputs, transfer functions, parameter variations, and perturbations. However, very little of the literature addresses methods for obtaining this structure, and none of this literature addresses a general methodology for obtaining a minimal M-delta model for a wide class of uncertainty. Since have a delta matrix of minimum order would improve the efficiency of structured singular value (or multivariable stability margin) computations, a method of obtaining a minimal M-delta model would be useful. A generalized method of obtaining a minimal M-delta structure for systems with real parameter variations is given.

Retrieval of haze properties and HCN concentrations from the three-micron spectrum of Titan

NASA Astrophysics Data System (ADS)

Kim, Sang J.; Lee, D. W.; Sim, C. K.; Seon, K. I.; Courtin, R.; Geballe, T. R.

2018-05-01

The 3 μm spectrum of Titan contains line emission and absorption as well as a significant haze continuum. The line emission has been previously analyzed in the literature, but that analysis has not properly included the influence of haze on the line emission. We report a new analysis of the 3 μm HCN emission spectrum using radiative transfer equations that include scattering and absorption by molecules and haze particles at altitudes lower than 500 km, where the influence of haze on the emergent spectrum becomes significant. Taking advantage of the dominance of resonant single scattering in the HCN ν3 fundamental and of the moderate haze optical thickness of the atmosphere around 3 μm, we adopt single dust and molecular scattering and present a formulation for the radiative transfer process. We evaluate the quantitative influence of haze scattering on the emission line intensities, and derive vertically-resolved single scattering albedos of the haze from model fits. We also present the resulting concentrations of HCN for altitudes below 500 km, where we find that the haze scattering significantly influences the retrieval of the concentrations of HCN. We conclude that the formulation we present is useful for the analysis of the HCN line emission from Titan and other similar hazy planetary or celestial objects.

Orodispersible films: Product transfer from lab-scale to continuous manufacturing.

PubMed

Thabet, Yasmin; Breitkreutz, Joerg

2018-01-15

Orodispersible films have been described as new beneficial dosage forms for special patient populations. Due to various production settings, different requirements on film formulations are required for non- continuous and continuous manufacturing. In this study, a continuous coating machine was qualified in regards of the process conditions for film compositions and their effects on the formed films. To investigate differences between both manufacturing processes, various film formulations of hydrochlorothiazide and hydroxypropylcellulose (HPC) or hydroxypropylmethycellulose (HPMC) as film formers were produced and the resulting films were characterized. The qualification of the continuously operating coating machine reveals no uniform heat distribution during drying. Coating solutions for continuous manufacturing should provide at least a dynamic viscosity of 1 Pa*s (wet film thickness of 500 μm, velocity of 15.9 cm/min). HPC films contain higher residuals of ethanol or acetone in bench-scale than in continuous production mode. Continuous production lead to lower drug content of the films. All continuously produced films disintegrate within less than 30 s. There are observed significant effects of the production process on the film characteristics. When transferring film manufacturing from lab-scale to continuous mode, film compositions, processing conditions and suitable characterization methods have to be carefully selected and adopted. Copyright © 2017 Elsevier B.V. All rights reserved.

Acetic Acid Can Catalyze Succinimide Formation from Aspartic Acid Residues by a Concerted Bond Reorganization Mechanism: A Computational Study

PubMed Central

Takahashi, Ohgi; Kirikoshi, Ryota; Manabe, Noriyoshi

2015-01-01

Succinimide formation from aspartic acid (Asp) residues is a concern in the formulation of protein drugs. Based on density functional theory calculations using Ace-Asp-Nme (Ace = acetyl, Nme = NHMe) as a model compound, we propose the possibility that acetic acid (AA), which is often used in protein drug formulation for mildly acidic buffer solutions, catalyzes the succinimide formation from Asp residues by acting as a proton-transfer mediator. The proposed mechanism comprises two steps: cyclization (intramolecular addition) to form a gem-diol tetrahedral intermediate and dehydration of the intermediate. Both steps are catalyzed by an AA molecule, and the first step was predicted to be rate-determining. The cyclization results from a bond formation between the amide nitrogen on the C-terminal side and the side-chain carboxyl carbon, which is part of an extensive bond reorganization (formation and breaking of single bonds and the interchange of single and double bonds) occurring concertedly in a cyclic structure formed by the amide NH bond, the AA molecule and the side-chain C=O group and involving a double proton transfer. The second step also involves an AA-mediated bond reorganization. Carboxylic acids other than AA are also expected to catalyze the succinimide formation by a similar mechanism. PMID:25588215

Acetic acid can catalyze succinimide formation from aspartic acid residues by a concerted bond reorganization mechanism: a computational study.

PubMed

Takahashi, Ohgi; Kirikoshi, Ryota; Manabe, Noriyoshi

2015-01-12

Succinimide formation from aspartic acid (Asp) residues is a concern in the formulation of protein drugs. Based on density functional theory calculations using Ace-Asp-Nme (Ace = acetyl, Nme = NHMe) as a model compound, we propose the possibility that acetic acid (AA), which is often used in protein drug formulation for mildly acidic buffer solutions, catalyzes the succinimide formation from Asp residues by acting as a proton-transfer mediator. The proposed mechanism comprises two steps: cyclization (intramolecular addition) to form a gem-diol tetrahedral intermediate and dehydration of the intermediate. Both steps are catalyzed by an AA molecule, and the first step was predicted to be rate-determining. The cyclization results from a bond formation between the amide nitrogen on the C-terminal side and the side-chain carboxyl carbon, which is part of an extensive bond reorganization (formation and breaking of single bonds and the interchange of single and double bonds) occurring concertedly in a cyclic structure formed by the amide NH bond, the AA molecule and the side-chain C=O group and involving a double proton transfer. The second step also involves an AA-mediated bond reorganization. Carboxylic acids other than AA are also expected to catalyze the succinimide formation by a similar mechanism.

A methodology for optimal MSW management, with an application in the waste transportation of Attica Region, Greece

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

Economopoulou, M.A.; Economopoulou, A.A.; Economopoulos, A.P., E-mail: eco@otenet.gr

2013-11-15

Highlights: • A two-step (strategic and detailed optimal planning) methodology is used for solving complex MSW management problems. • A software package is outlined, which can be used for generating detailed optimal plans. • Sensitivity analysis compares alternative scenarios that address objections and/or wishes of local communities. • A case study shows the application of the above procedure in practice and demonstrates the results and benefits obtained. - Abstract: The paper describes a software system capable of formulating alternative optimal Municipal Solid Wastes (MSWs) management plans, each of which meets a set of constraints that may reflect selected objections and/ormore » wishes of local communities. The objective function to be minimized in each plan is the sum of the annualized capital investment and annual operating cost of all transportation, treatment and final disposal operations involved, taking into consideration the possible income from the sale of products and any other financial incentives or disincentives that may exist. For each plan formulated, the system generates several reports that define the plan, analyze its cost elements and yield an indicative profile of selected types of installations, as well as data files that facilitate the geographic representation of the optimal solution in maps through the use of GIS. A number of these reports compare the technical and economic data from all scenarios considered at the study area, municipality and installation level constituting in effect sensitivity analysis. The generation of alternative plans offers local authorities the opportunity of choice and the results of the sensitivity analysis allow them to choose wisely and with consensus. The paper presents also an application of this software system in the capital Region of Attica in Greece, for the purpose of developing an optimal waste transportation system in line with its approved waste management plan. The formulated plan was able to: (a) serve 113 Municipalities and Communities that generate nearly 2 million t/y of comingled MSW with distinctly different waste collection patterns, (b) take into consideration several existing waste transfer stations (WTS) and optimize their use within the overall plan, (c) select the most appropriate sites among the potentially suitable (new and in use) ones, (d) generate the optimal profile of each WTS proposed, and (e) perform sensitivity analysis so as to define the impact of selected sets of constraints (limitations in the availability of sites and in the capacity of their installations) on the design and cost of the ensuing optimal waste transfer system. The results show that optimal planning offers significant economic savings to municipalities, while reducing at the same time the present levels of traffic, fuel consumptions and air emissions in the congested Athens basin.« less

35. FUEL HANDLING BUILDING, INTERIOR LOOKING SOUTHEAST SHOWING TRANSFER CANAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. FUEL HANDLING BUILDING, INTERIOR LOOKING SOUTHEAST SHOWING TRANSFER CANAL AREA, DEEP STORAGE AREA, FUEL STORAGE PIT (LOCATION BB) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

Multi-criteria GIS-based siting of transfer station for municipal solid waste: The case of Kumasi Metropolitan Area, Ghana.

PubMed

Bosompem, Christian; Stemn, Eric; Fei-Baffoe, Bernard

2016-10-01

The increase in the quantity of municipal solid waste generated as a result of population growth in most urban areas has resulted in the difficulty of locating suitable land areas to be used as landfills. To curb this, waste transfer stations are used. The Kumasi Metropolitan Area, even though it has an engineered landfill, is faced with the problem of waste collection from the generation centres to the final disposal site. Thus in this study, multi-criteria decision analysis incorporated into a geographic information system was used to determine potential waste transfer station sites. The key result established 11 sites located within six different sub-metros. This result can be used by decision makers for site selection of the waste transfer stations after taking into account other relevant ecological and economic factors. © The Author(s) 2016.

Space benefits: The secondary application of aerospace technology in other sectors of the economy

NASA Technical Reports Server (NTRS)

1976-01-01

A 'Benefit Briefing Notebook' was prepared for the NASA Technology Utilization Office to provide accurate, convenient, and integrated resource information on the transfer of aerospace technology to other sectors of the U.S. economy. The contents are divided into three sections: (1) transfer overview, (2) benefit cases, and (3) indexes. The transfer overview section provides a general perspective for technology transfer from NASA to other organizations. In addition to a description of the basic transfer modes, the selection criteria for notebook examples and the kinds of benefit data they contain are also presented. The benefits section is subdivided into nineteen subject areas. Each subsection presents one or more key issues of current interest, with discrete transfer cases related to each key issue. Additional transfer examples relevant to each subject area are then presented. Pertinent transfer data are given at the end of each example.

Use of Fixed Dose Combination (FDC) Drugs in India: Central Regulatory Approval and Sales of FDCs Containing Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), Metformin, or Psychotropic Drugs

PubMed Central

McGettigan, Patricia; Roderick, Peter; Mahajan, Rushikesh; Kadam, Abhay; Pollock, Allyson M.

2015-01-01

Background In 2012, an Indian parliamentary committee reported that manufacturing licenses for large numbers of fixed dose combination (FDC) drugs had been issued by state authorities without prior approval of the Central Drugs Standard Control Organization (CDSCO) in violation of rules, and considered that some ambiguity until 1 May 2002 about states’ powers might have contributed. To our knowledge, no systematic enquiry has been undertaken to determine if evidence existed to support these findings. We investigated CDSCO approvals for and availability of oral FDC drugs in four therapeutic areas: analgesia (non-steroidal anti-inflammatory drugs [NSAIDs]), diabetes (metformin), depression/anxiety (anti-depressants/benzodiazepines), and psychosis (anti-psychotics). Methods and Findings This was an ecologic study with a time-trend analysis of FDC sales volumes (2007–2012) and a cross-sectional examination of 2011–2012 data to establish the numbers of formulations on the market with and without a record of CDSCO approval (“approved” and “unapproved”), their branded products, and sales volumes. Data from the CDSCO on approved FDC formulations were compared with sales data from PharmaTrac, a database of national drug sales. We determined the proportions of FDC sales volumes (2011–2012) arising from centrally approved and unapproved formulations and from formulations including drugs banned/restricted internationally. We also determined the proportions of centrally approved and unapproved formulations marketed before and after 1 May 2002, when amendments were made to the drug rules. FDC approvals in India, the United Kingdom (UK), and United States of America (US) were compared. For NSAID FDCs, 124 formulations were marketed, of which 34 (27%) were centrally approved and 90 (73%) were unapproved; metformin: 25 formulations, 20 (80%) approved, five (20%) unapproved; anti-depressants/benzodiazepines: 16 formulations, three (19%) approved, 13 (81%) unapproved; anti-psychotics: ten formulations, three (30%) approved, seven (70%) unapproved. After 1 May 2002, the proportions of approved FDC formulations increased for NSAIDs (26%/28%) and anti-psychotics (0%/38%) and decreased for metformin (100%/75%) and anti-depressants/benzodiazepines (20%/18%), and the overall proportion approved remained similar before and after that date. FDC formulations gave rise to multiple branded products, ranging from 211 anti-psychotic FDC products from ten formulations to 2,739 NSAID FDC products from 124 formulations. The proportions of FDC sales volumes arising from unapproved formulations were as follows: anti-depressants/benzodiazepines, 69%; anti-psychotics, 43%; NSAIDs, 28%; and metformin, 0.4%. Formulations including drugs banned/restricted internationally comprised over 12% of NSAID FDC sales and 53% of anti-psychotic FDC sales. Across the four therapeutic areas, 14 FDC formulations were approved in the UK and 22 in the US. Conclusions There was evidence supporting concerns about FDCs. Metformin excepted, substantial numbers of centrally unapproved formulations for NSAID, anti-depressant/benzodiazepine, and anti-psychotic FDCs were marketed; sales volumes were high. The legal need for central approval of new drugs before manufacture has been in place continuously since 1961, including for FDCs meeting the applicable legal test. Proportions of centrally unapproved formulations after 1 May 2002 did not decrease overall, and no ambiguity was found about states’ licensing powers. Unapproved formulations should be banned immediately, prioritising those withdrawn/banned internationally and undertaking a review of benefits and risks for patients in ceasing or switching to other medicines. Drug laws need to be amended to ensure the safety and effectiveness of medicines marketed in India. PMID:25965416

Higher mortality in areas of lower socioeconomic position measured by a single index of deprivation in Japan.

PubMed

Fukuda, Yoshiharu; Nakamura, Keiko; Takano, Takehito

2007-03-01

To formulate an index representing area deprivation and elucidate the relation between the index and mortality in Japan. Ecological study for prefectures (N=47) and municipalities (N=3366) across Japan. Based on socioeconomic indicators of seven domains of deprivation (i.e. unemployment, overcrowding, low social class and poverty, low education, no home ownership, low income and vulnerable group), an index was formulated using the z-scoring method. The relation between the index and mortality was examined by correlation analysis, hierarchical Poisson regression and comparison of standardized mortality ratio according to the index. The deprivation index ranged from -7.48 to 10.98 for prefectures and from -16.97 to 13.82 for municipalities. The index was significantly positively correlated with prefectural mortality, especially in the population aged under 74 years: r=0.65 for men and r=0.41 for women. At the municipal level, hierarchical Poisson regression showed a significant positive coefficient of the index to mortality for both men and women, and excess mortality in the most deprived fifth compared to the least deprived fifth was 26.4% in men and 11.8% in women. We formulated a deprivation index, which was substantially related to mortality at the prefectural and municipal levels. This study highlights the higher risk of dying among populations in socially disadvantaged areas and encourages the use of indices representing area socioeconomic conditions for further studies of area effects on health.

A Comparison of Performance Characteristics of Multistage Thermoelectric Coolers Based on Different Ceramic Substrates

NASA Astrophysics Data System (ADS)

Semenyuk, V.

2014-06-01

The influence of the thermal properties of the substrate on the performance of cascade thermoelectric coolers (TECs) is studied with an emphasis on a justified choice of substrate material. An analytical model is developed for predicting the thermal resistance of the substrate associated with three-dimensional heat transfer from a smaller cascade area into a larger cooling cascade. The model is used to define the maximum temperature difference for a line of standard multistage TECs based on various substrate materials with different thermal conductivities, including white 96% Al2O3 "Rubalit" ceramic, grey 99.8% Al2O3 "Policor" ceramic, and AlN and BeO ceramics. Two types of multistage TECs are considered, namely with series and series-parallel connection of TE pellets, having from two to five cascades with TE pellet length in the range from 0.3 mm to 2 mm. A comparative analysis of the obtained results is made, and recommendations are formulated concerning the selection of an appropriate substrate material providing the highest performance-to-cost ratio.

Immunotherapeutic strategies for the treatment of renal cell carcinoma: Where will we go?

PubMed

Anselmo Da Costa, Inês; Rausch, Steffen; Kruck, Stephan; Todenhöfer, Tilman; Stenzl, Arnulf; Bedke, Jens

2017-04-01

Historically, renal cell carcinoma (RCC) is considered a chemotherapy-resistant tumor. The cornerstone of systemic therapy included mammalian target of rapamycin (mTOR) inhibitors, endothelial growth factor receptor (VEGFR) and tyrosine kinase inhibitors (TKIs). Currently, a new era is enteres with promising immunotherapeutic treatments, which are becoming commercially available. Areas covered: We provide a comprehensive review using PubMed and ClinicalTrials.gov about the following immunotherapies in RCC: i) vaccine therapy, ii) adoptive T Cell Transfer and CAR T cells, iii) nonspecific immunotherapy - IL-2 (new formulations), iv) Checkpoint inhibitors, v) other checkpoint-molecules. We will also discuss their mechanism of action and toxicity, the importance of developing new patient selection algorithms (immunoprofiling, guidelines updates) and new biomarkers such as PD-1 expression. Expert commentary: Immunotherapy shows promise, and the current tools used in clinical practice, including guidelines, staging-classification and algorithms should be revised and adapted to the new immunotherapeutic drugs. Although immunotherapy in RCC show promising results, more research is needed in parallel to discover biomarkers that enable the prediction of a treatment response and therefore lead to better patient selection.

A single field of view method for retrieving tropospheric temperature profiles from cloud-contaminated radiance data

NASA Technical Reports Server (NTRS)

Hodges, D. B.

1976-01-01

An iterative method is presented to retrieve single field of view (FOV) tropospheric temperature profiles directly from cloud-contaminated radiance data. A well-defined temperature profile may be calculated from the radiative transfer equation (RTE) for a partly cloudy atmosphere when the average fractional cloud amount and cloud-top height for the FOV are known. A cloud model is formulated to calculate the fractional cloud amount from an estimated cloud-top height. The method is then examined through use of simulated radiance data calculated through vertical integration of the RTE for a partly cloudy atmosphere using known values of cloud-top height(s) and fractional cloud amount(s). Temperature profiles are retrieved from the simulated data assuming various errors in the cloud parameters. Temperature profiles are retrieved from NOAA-4 satellite-measured radiance data obtained over an area dominated by an active cold front and with considerable cloud cover and compared with radiosonde data. The effects of using various guessed profiles and the number of iterations are considered.

Groundwater-level change and evaluation of simulated water levels for irrigated areas in Lahontan Valley, Churchill County, west-central Nevada, 1992 to 2012

USGS Publications Warehouse

Smith, David W.; Buto, Susan G.; Welborn, Toby L.

2016-09-14

The acquisition and transfer of water rights to wetland areas of Lahontan Valley, Nevada, has caused concern over the potential effects on shallow aquifer water levels. In 1992, water levels in Lahontan Valley were measured to construct a water-table map of the shallow aquifer prior to the effects of water-right transfers mandated by the Fallon Paiute-Shoshone Tribal Settlement Act of 1990 (Public Law 101-618, 104 Stat. 3289). From 1992 to 2012, approximately 11,810 water-righted acres, or 34,356 acre-feet of water, were acquired and transferred to wetland areas of Lahontan Valley. This report documents changes in water levels measured during the period of water-right transfers and presents an evaluation of five groundwater-flow model scenarios that simulated water-level changes in Lahontan Valley in response to water-right transfers and a reduction in irrigation season length by 50 percent.Water levels measured in 98 wells from 2012 to 2013 were used to construct a water-table map. Water levels in 73 of the 98 wells were compared with water levels measured in 1992 and used to construct a water-level change map. Water-level changes in the 73 wells ranged from -16.2 to 4.1 feet over the 20-year period. Rises in water levels in Lahontan Valley may correspond to annual changes in available irrigation water, increased canal flows after the exceptionally dry and shortened irrigation season of 1992, and the increased conveyance of water rights transferred to Stillwater National Wildlife Refuge. Water-level declines generally occurred near the boundary of irrigated areas and may be associated with groundwater pumping, water-right transfers, and inactive surface-water storage reservoirs. The largest water-level declines were in the area near Carson Lake.Groundwater-level response to water-right transfers was evaluated by comparing simulated and observed water-level changes for periods representing water-right transfers and a shortened irrigation season in areas near Fallon and Stillwater, Nevada. In the Stillwater modeled area, water rights associated with nearly 50 percent of the irrigated land were transferred from 1992 to 1998, represented by the model scenario reduction in groundwater recharge by 50 percent. The scenario resulted in a simulated average decline of 0.6 foot; average observed water-level change for the modeled area was estimated to be 0.0 foot, or no change. In the Fallon modeled area, transfers of water rights associated with 180 acres of land occurred from 1994 to 2008. The transfer is most similar to the scenario for removal of 320 acres of irrigated land. The model scenario resulted in simulated water-level declines of 0.1; water levels measured from 1994 to 2012 indicate no significant trends in water levels, or approximately zero change in water levels, for the Fallon modeled area.The model scenarios included the simulation of a irrigation season shortened by 50 percent, which was determined to have occurred in the 1992 irrigation season in both modeled areas. The shortening of the irrigation season in the Fallon modeled area resulted in simulated water-level declines of 1.1 feet; observed declines were estimated to be 1.3 feet. The Stillwater model simulations resulted in a simulated decline of 1.4 feet, and observed water levels declined an estimated 2.3 feet for the area. The estimated difference between simulated and observed water levels are 0.2 and 0.9 foot for the Fallon and Stillwater modeled areas, respectively. Observed water-level changes were generally within one standard deviation of changes from model simulations, based on the selected periods of comparison. Simulated and observed water-level changes agree well, generally within 1 foot; however, the model scenarios were only approximately similar to the observed conditions, and periods of comparison were generally shorter for the observed periods and included additional cumulative effects of water-right transfers. Climate variability was not considered in the model scenarios.

Rosin-enabled ultraclean and damage-free transfer of graphene for large-area flexible organic light-emitting diodes

PubMed Central

Zhang, Zhikun; Du, Jinhong; Zhang, Dingdong; Sun, Hengda; Yin, Lichang; Ma, Laipeng; Chen, Jiangshan; Ma, Dongge; Cheng, Hui-Ming; Ren, Wencai

2017-01-01

The large polymer particle residue generated during the transfer process of graphene grown by chemical vapour deposition is a critical issue that limits its use in large-area thin-film devices such as organic light-emitting diodes. The available lighting areas of the graphene-based organic light-emitting diodes reported so far are usually <1 cm2. Here we report a transfer method using rosin as a support layer, whose weak interaction with graphene, good solubility and sufficient strength enable ultraclean and damage-free transfer. The transferred graphene has a low surface roughness with an occasional maximum residue height of about 15 nm and a uniform sheet resistance of 560 Ω per square with about 1% deviation over a large area. Such clean, damage-free graphene has produced the four-inch monolithic flexible graphene-based organic light-emitting diode with a high brightness of about 10,000 cd m−2 that can already satisfy the requirements for lighting sources and displays. PMID:28233778

High-surface-area architectures for improved charge transfer kinetics at the dark electrode in dye-sensitized solar cells.

PubMed

Hoffeditz, William L; Katz, Michael J; Deria, Pravas; Martinson, Alex B F; Pellin, Michael J; Farha, Omar K; Hupp, Joseph T

2014-06-11

Dye-sensitized solar cell (DSC) redox shuttles other than triiodide/iodide have exhibited significantly higher charge transfer resistances at the dark electrode. This often results in poor fill factor, a severe detriment to device performance. Rather than moving to dark electrodes of untested materials that may have higher catalytic activity for specific shuttles, the surface area of platinum dark electrodes could be increased, improving the catalytic activity by simply presenting more catalyst to the shuttle solution. A new copper-based redox shuttle that experiences extremely high charge-transfer resistance at conventional Pt dark electrodes yields cells having fill-factors of less than 0.3. By replacing the standard Pt dark electrode with an inverse opal Pt electrode fabricated via atomic layer deposition, the dark electrode surface area is boosted by ca. 50-fold. The resulting increase in interfacial electron transfer rate (decrease in charge-transfer resistance) nearly doubles the fill factor and therefore the overall energy conversion efficiency, illustrating the utility of this high-area electrode for DSCs.

Water law as an adaptation strategy for global water scarcity in the future

NASA Astrophysics Data System (ADS)

Kakinuma, K.; Yoshikawa, S.; Endo, T.; Kanae, S.

2014-12-01

Water scarcity due to climate changes and growing human population is a major concern for the world. Adaptation and mitigation strategies should be developed for water scarcity in the future. Previous studies assessed the future water availability by hard technology (e.g., reservoirs, reclaimed and desalinated water plants) as adaptation strategies. On the other hand, soft path such as water law and policy would also be important for adaptation strategies. Water transfers is reallocation of water among water users. For example, distribution of the amount of available water is often heterogeneous especially during drought periods. If water transfers are permitted in these areas, water can be moved from surplus areas/sections to critical need areas/sections. There are several studies which describe the water transfer at the local scales (i.e., water bank in California), however the factors that determined the establishment of water transfer are not clear. If we can detect the factors, it could be used to estimate in which areas the water transfer would come into existence. This in turn would reduce the water stress. Here, we focus on historical interaction between human activity and water environments. Generally, rules of water use are developed by repeated discussion among water users. The frequency of these discussions would be related with their land use, frequency of drought and water resource sizes. For example, people in rice crop area need to discuss about water allocation compared to wheat crop area. Therefore, we examine the relationship between the permission of water transfer and factors such as water environment and human activity in the world.

A Phase 2 randomized, observer-blind, placebo-controlled, dose-ranging trial of aluminum-adjuvanted respiratory syncytial virus F particle vaccine formulations in healthy women of childbearing age.

PubMed

August, Allison; Glenn, Gregory M; Kpamegan, Eloi; Hickman, Somia P; Jani, Dewal; Lu, Hanxin; Thomas, D Nigel; Wen, Judy; Piedra, Pedro A; Fries, Louis F

2017-06-27

Respiratory syncytial virus (RSV) causes significant morbidity and mortality in infants. We are developing an RSV fusion (F) protein nanoparticle vaccine for immunization of third trimester pregnant women to passively protect infants through transfer of RSV-specific maternal antibodies. The present trial was performed to assess the immunogenicity and safety of several formulations of RSV F vaccine in 1-dose or 2-dose schedules. Placebo, or vaccine with 60μg or 120μg RSV F protein and 0.2, 0.4, or 0.8mg aluminum, were administered intramuscularly on Days 0 and 28 to healthy women 18-35years old. Immunogenicity was assessed from Days 0 through 91 based on anti-F IgG and palivizumab-competitive antibody (PCA) by ELISA, and RSV A and B neutralizing antibodies by microneutralization (MN) assay. Solicited adverse events were collected through Day 7 and unsolicited adverse events through Day 91. All formulations were well-tolerated, with no treatment-related serious adverse events. Anti-F IgG and PCA responses were correlated and increased after both doses, while MN increased significantly only after the first dose, then plateaued. The timeliest and most robust antibody responses followed one dose of 120μg RSV F protein and 0.4mg aluminum, but persistence through 91days was modestly (∼25%) superior following two doses of 60μg RSV F protein and 0.8mg aluminum. Western blot analysis showed RSV infections in active vaccinees were reduced by 52% overall (p=0.009 overall) over the Day 0 through 90 period. RSV F nanoparticle vaccine formulations were well tolerated and immunogenic. The optimal combination of convenience and rapid response for immunization in the third trimester occurred with 120μg RSV F and 0.4mg aluminum, which achieved peak immune responses in 14days and sufficient persistence through 91days to allow for passive transfer of IgG antibodies to the fetus. NCT01960686. Copyright © 2017 Novavax. Published by Elsevier Ltd.. All rights reserved.

Synthesis of a novel superdisintegrant by starch derivatization with polysuccinimide and its application for the development of Ondansetron fast dissolving tablet.

PubMed

Sadeghi, Mozhgan; Hemmati, Salar; Hamishehkar, Hamed

2016-01-01

Disintegrants are the key excipients administered in tablet formulations to boost the decomposition of the tablet into smaller pieces in the gastrointestinal environment, thereby increasing the available surface area and enhancing a more rapid release of the active ingredient. Polysuccinimide (PSI), a biodegradable polymer synthesized from aspartic acid, was reacted with starch and fully assessed by CHN, (1)H-NMR, and FTIR. PSI-grafted starch (PSI-St) was synthesized and applied as a disintegrant in the formulation of a rapidly disintegrating tablet of Ondansetron, a nausea and vomiting medicine. The tablet formulated with the newly developed superdisintegrant was evaluated for hardness, friability, disintegration time, and dissolution rate, and the results were compared with tablets formulated with an identical composition of test formulation differing only in type of disintegrant. Tablets prepared with starch and tablets prepared with sodium starch glycolate (SSG) were used as negative and positive controls, respectively. Dissolution study results indicated that although the onset of disintegration action was faster for SSG than PSI-St, higher amounts of drug were released from tablets formulated from PSI-St than from those formulated from SSG during 10 min. It was concluded that the novel synthesized superdisintegrant has an appropriate potential for the application in the formulation of fast dissolving tablets.

Synthesis of a novel superdisintegrant by starch derivatization with polysuccinimide and its application for the development of Ondansetron fast dissolving tablet.

PubMed

Sadeghi, Mozhgan; Hemmati, Salar; Hamishehkar, Hamed

2016-05-01

Disintegrants are the key excipients administered in tablet formulations to boost the decomposition of the tablet into smaller pieces in the gastrointestinal environment, thereby increasing the available surface area and enhancing a more rapid release of the active ingredient. Polysuccinimide (PSI), a biodegradable polymer synthesized from aspartic acid, was reacted with starch and fully assessed by CHN, 1 H-NMR, and FTIR. PSI-grafted starch (PSI-St) was synthesized and applied as a disintegrant in the formulation of a rapidly disintegrating tablet of Ondansetron, a nausea and vomiting medicine. The tablet formulated with the newly developed superdisintegrant was evaluated for hardness, friability, disintegration time, and dissolution rate, and the results were compared with tablets formulated with an identical composition of test formulation differing only in type of disintegrant. Tablets prepared with starch and tablets prepared with sodium starch glycolate (SSG) were used as negative and positive controls, respectively. Dissolution study results indicated that although the onset of disintegration action was faster for SSG than PSI-St, higher amounts of drug were released from tablets formulated from PSI-St than from those formulated from SSG during 10 min. It was concluded that the novel synthesized superdisintegrant has an appropriate potential for the application in the formulation of fast dissolving tablets.

Influence of niacinamide containing formulations on the molecular and biophysical properties of the stratum corneum.

PubMed

Mohammed, D; Crowther, J M; Matts, P J; Hadgraft, J; Lane, M E

2013-01-30

Niacinamide-containing moisturisers are known be efficacious in alleviating dry skin conditions and improving stratum corneum (SC) barrier function. However, the mechanisms of action of niacinamide at the molecular level in the SC are still not well understood. Previously, we have reported the development of novel methods to probe SC barrier properties in vivo. The aim of the present study was to characterise changes in Trans Epidermal Water Loss (TEWL), corneocyte surface area and maturity, selected protease activities and SC thickness after repeated application of a simple vehicle containing niacinamide. A commercial formulation was also included as a reference. The left and right mid-volar forearms of 20 healthy volunteers were used as study sites, to which topical formulations were applied twice daily for 28 days. After successive tape-stripping, corneocyte maturity and surface area were assessed. In addition, activity of the desquamatory kallikrein (KLK) protease enzymes KLK5 and KLK7, and tryptase and plasmin (implicated in inflammatory process) were measured using a fluorogenic probe assay. The amount of protein removed and TEWL were also recorded. SC thickness before and after treatment was determined using Confocal Raman Spectroscopy (CRS). Overall (i) corneocyte maturity and surface area decreased with increasing number of tape strips, (ii) activity of both the desquamatory and inflammatory enzymes was highest in the outer layers of the SC and decreased with depth (iii) TEWL increased as more SC layers were removed. Furthermore, areas treated with formulations containing niacinamide were significantly different to pre-treatment baseline and untreated/vehicle-control treated sites, with larger and more mature corneocytes, decreased inflammatory activity, decreased TEWL and increased SC thickness. These data (a) confirm the utility of measures and metrics developed previously for the non-invasive assay of SC barrier function, (b) present an holistic picture of a SC compartment managing barrier function through dynamic optimisation of pathlength and quality of building materials used, and (c) shed new light on niacinamide as a topical formulation adjunct with unique SC barrier-augmentation properties. Copyright © 2012 Elsevier B.V. All rights reserved.

DNA/RNA-based formulations for treatment of breast cancer.

PubMed

Xie, Zhaolu; Zeng, Xianghui

2017-12-01

To develop a successful formulation for the gene therapy of breast cancer, an effective therapeutic nucleic acid and a proper delivery system are essential. Increased understanding of breast cancer, and developments in biotechnology, material science and nanotechnology have provided a major impetus in the development of effective formulations for the gene therapy of breast cancer. Areas covered: We discuss DNA/RNA-based formulations that can inhibit the growth of breast cancer cells and control the progress of breast cancer. Targets for the gene therapy of breast cancer, DNA/RNA-based therapeutics and delivery systems are summarized. And examples of successful DNA/RNA-based formulations for breast cancer gene therapy are reviewed. Expert opinion: Several challenges remain in developing effective DNA/RNA-based formulations for treatment of breast cancer. Firstly, most of the currently utilized targets are not effective enough as monotherapy for breast cancer. Secondly, the requirements for co-delivery system make the preparation of formulation more complicated. Thirdly, nanoparticles with the modification of tumor-targeting ligands could be more unstable in circulation and normal tissues. Lastly, immune responses against the viral vectors are unfavorable for the gene therapy of breast cancer because of the damage to the host and the impaired therapeutic ability.

General Relativistic Radiative Transfer and GeneralRelativistic MHD Simulations of Accretion and Outflows of Black Holes

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

Fuerst, Steven V.; /KIPAC, Menlo Park; Mizuno, Yosuke

2007-01-05

We calculate the emission from relativistic flows in black hole systems using a fully general relativistic radiative transfer formulation, with flow structures obtained by general relativistic magneto-hydrodynamic simulations. We consider thermal free-free emission and thermal synchrotron emission. Bright filament-like features protrude (visually) from the accretion disk surface, which are enhancements of synchrotron emission where the magnetic field roughly aligns with the line-of-sight in the co-moving frame. The features move back and forth as the accretion flow evolves, but their visibility and morphology are robust. We propose that variations and drifts of the features produce certain X-ray quasi-periodic oscillations (QPOs) observedmore » in black-hole X-ray binaries.« less

PURDU-WINCOF: A computer code for establishing the performance of a fan-compressor unit with water ingestion

NASA Technical Reports Server (NTRS)

Leonardo, M.; Tsuchiya, T.; Murthy, S. N. B.

1982-01-01

A model for predicting the performance of a multi-spool axial-flow compressor with a fan during operation with water ingestion was developed incorporating several two-phase fluid flow effects as follows: (1) ingestion of water, (2) droplet interaction with blades and resulting changes in blade characteristics, (3) redistribution of water and water vapor due to centrifugal action, (4) heat and mass transfer processes, and (5) droplet size adjustment due to mass transfer and mechanical stability considerations. A computer program, called the PURDU-WINCOF code, was generated based on the model utilizing a one-dimensional formulation. An illustrative case serves to show the manner in which the code can be utilized and the nature of the results obtained.

Investigation of Aggregates as a Model for Titan's Aerosols Using Microwave Analog Experiments and Radiative Transfer Theory

NASA Astrophysics Data System (ADS)

Thomas-Osip, J. E.; Gustafson, B. Å. S.

1996-09-01

It has been suggested that the aerosols in the atmosphere of Titan have an aggregate morphology (Bar-Nun et al., 1988: West and Smith, 1991). Previous studies were based on formulations of the Discrete Dipole Approximation to calculate the single scattering properties of such aggregates. These studies were limited in the size of the individual spheres and total size of the aggregate. We present microwave to light analog scattering measurements and radiative transfer calculations for aggregates of 250-500 individual spheres near the Raleigh size limit in a plane parallel atmosphere. The advantages of using microwave analog experiments include the possibility of investigating a broad range of particle sizes and morphologies.

Analysis of longwave radiation for the Earth-atmosphere system

NASA Technical Reports Server (NTRS)

Tiwari, S. N.; Venuru, C. S.; Subramanian, S. V.

1983-01-01

Accurate radiative transfer models are used to determine the upwelling atmospheric radiance and net radiative flux in the entire longwave spectral range. The validity of the quasi-random band model is established by comparing the results of this model with those of line-by-line formulations and with available theoretical and experimental results. Existing radiative transfer models and computer codes are modified to include various surface and atmospheric effects (surface reflection, nonequilibrium radiation, and cloud effects). The program is used to evaluate the radiative flux in clear atmosphere, provide sensitivity analysis of upwelling radiance in the presence of clouds, and determine the effects of various climatological parameters on the upwelling radiation and anisotropic function. Homogeneous and nonhomogeneous gas emissivities can also be evaluated under different conditions.

Homogeneous-heterogeneous reactions in curved channel with porous medium

NASA Astrophysics Data System (ADS)

Hayat, T.; Ayub, Sadia; Alsaedi, A.

2018-06-01

Purpose of the present investigation is to examine the peristaltic flow through porous medium in a curved conduit. Problem is modeled for incompressible electrically conducting Ellis fluid. Influence of porous medium is tackled via modified Darcy's law. The considered model utilizes homogeneous-heterogeneous reactions with equal diffusivities for reactant and autocatalysis. Constitutive equations are formulated in the presence of viscous dissipation. Channel walls are compliant in nature. Governing equations are modeled and simplified under the assumptions of small Reynolds number and large wavelength. Graphical results for velocity, temperature, heat transfer coefficient and homogeneous-heterogeneous reaction parameters are examined for the emerging parameters entering into the problem. Results reveal an activation in both homogenous-heterogenous reaction effect and heat transfer rate with increasing curvature of the channel.

Enhanced Flexibility of the O2 + N2 Interaction and Its Effect on Collisional Vibrational Energy Exchange.

PubMed

Garcia, E; Laganà, A; Pirani, F; Bartolomei, M; Cacciatore, M; Kurnosov, A

2016-07-14

Prompted by a comparison of measured and computed rate coefficients of Vibration-to-Vibration and Vibration-to-Translation energy transfer in O2 + N2 non-reactive collisions, extended semiclassical calculations of the related cross sections were performed to rationalize the role played by attractive and repulsive components of the interaction on two different potential energy surfaces. By exploiting the distributed concurrent scheme of the Grid Empowered Molecular Simulator we extended the computational work to quasiclassical techniques, investigated in this way more in detail the underlying microscopic mechanisms, singled out the interaction components facilitating the energy transfer, improved the formulation of the potential, and performed additional calculations that confirmed the effectiveness of the improvement introduced.

Vaginal distribution and retention of a multiparticulate drug delivery system, assessed by gamma scintigraphy and magnetic resonance imaging.

PubMed

Mehta, Samata; Verstraelen, Hans; Peremans, Kathelijne; Villeirs, Geert; Vermeire, Simon; De Vos, Filip; Mehuys, Els; Remon, Jean Paul; Vervaet, Chris

2012-04-15

For any new vaginal dosage form, the distribution and retention in the vagina has to be assessed by in vivo evaluation. We evaluated the vaginal distribution and retention of starch-based pellets in sheep as live animal model by gamma scintigraphy (using Indium-111 DTPA as radiolabel) and in women via magnetic resonance imaging (MRI, using a gadolinium chelate as contrast agent). A conventional cream formulation was used as reference in both studies. Cream and pellets were administered to sheep (n=6) in a two period-two treatment study and to healthy female volunteers (n=6) via a randomized crossover trial. Pellets (filled into hard gelatin capsule) and cetomacrogol cream, both labeled with Indium-111 DTPA (for gamma scintigraphy) or with gadolinium chelate (for MRI) were evaluated for their intravaginal distribution and retention over a 24h period. Spreading in the vagina was assessed based on the part of the vagina covered with formulation (expressed in relation to the total vaginal length). Vaginal retention of the formulation was quantified based on the radioactivity remaining in the vaginal area (sheep study), or qualitatively evaluated (women study). Both trials indicated a rapid distribution of the cream within the vagina as complete coverage of the vaginal mucosa was seen 1h after dose administration. Clearance of the cream was rapid: about 10% activity remained in the vaginal area of the sheep 12h post-administration, while after 8h only a thin layer of cream was detected on the vaginal mucosa of women. After disintegration of the hard gelatin capsule, the pellet formulation gradually distributed over the entire vaginal mucosa. Residence time of the pellets in the vagina was longer compared to the semi-solid formulation: after 24h 23 ± 7% radioactivity was detected in the vaginal area of the sheep, while in women the pellet formulation was still detected throughout the vagina. A multi-particulate system containing starch-based pellets was identified as a promising novel vaginal drug delivery system, resulting in complete coverage of the vaginal mucosa and long retention time. Copyright © 2012 Elsevier B.V. All rights reserved.

The areal reduction factor: A new analytical expression for the Lazio Region in central Italy

NASA Astrophysics Data System (ADS)

Mineo, C.; Ridolfi, E.; Napolitano, F.; Russo, F.

2018-05-01

For the study and modeling of hydrological phenomena, both in urban and rural areas, a proper estimation of the areal reduction factor (ARF) is crucial. In this paper, we estimated the ARF from observed rainfall data as the ratio between the average rainfall occurring in a specific area and the point rainfall. Then, we compared the obtained ARF values with some of the most widespread empirical approaches in literature which are used when rainfall observations are not available. Results highlight that the literature formulations can lead to a substantial over- or underestimation of the ARF estimated from observed data. These findings can have severe consequences, especially in the design of hydraulic structures where empirical formulations are extensively applied. The aim of this paper is to present a new analytical relationship with an explicit dependence on the rainfall duration and area that can better represent the ARF-area trend over the area case of study. The analytical curve presented here can find an important application to estimate the ARF values for design purposes. The test study area is the Lazio Region (central Italy).

Determination of the efficacy of preservation of non-eye area water-miscible cosmetic and toiletry formulations: collaborative study.

PubMed

Machtiger, N A; Fischler, G E; Adams, M C; Spielmaker, R; Graf, J F

2001-01-01

A collaborative study was conducted to test a method developed to distinguish between adequately and inadequately preserved cosmetic formulations. Nineteen laboratories participated in the study. Samples tested included shampoos, hair conditioners, oil-in-water emulsions, and water-in-oil-emulsions. Triplicate samples of 4 adequately preserved and 4 inadequately preserved cosmetic products were tested by each collaborative laboratory. Results showed that all inadequately preserved shampoo and conditioner samples failed to meet the acceptance criteria for adequately preserved formulations. Of the 51 preserved samples, 49 shampoos and 48 conditioners met the criteria for adequate preservation. All samples of inadequately preserved water-in-oil emulsions and oil-in-water emulsions failed to meet the acceptance criteria, whereas all adequately preserved emulsion formulations met the acceptance criteria.

Electron transfer processes occurring on platinum neural stimulating electrodes: pulsing experiments for cathodic-first, charge-balanced, biphasic pulses for 0.566  ⩽  k  ⩽  2.3 in rat subcutaneous tissues

NASA Astrophysics Data System (ADS)

Kumsa, Doe W.; Bhadra, Narendra; Hudak, Eric M.; Mortimer, J. Thomas

2017-10-01

Objective. Our mission is twofold: (1) find a way to safely inject more charge through platinum electrodes than the Shannon limit (k  =  1.75) permits and (2) nurture an interest in the neural stimulation community to understand the electron transfer process occurring on neural stimulating electrodes. Approach. We report here on measurements of the electrode potential, performed on platinum neural stimulating electrodes in the subcutaneous space of an anesthetized rat under neural stimulation conditions. Main results. The results for six platinum electrodes with areas ranging from 0.2 mm2 to 12.7 mm2 were similar to prior results in sulfuric acid, except that the measured potentials were shifted negative 0.36 V because of the pH difference between the two media. The anodic ‘end’ potential, measured at t  =  20 ms after the onset of the biphasic current pulse, was the primary focus of the data collected because previous results had shown that as charge injection crosses the Shannon limit (k  =  1.75), this potential moves into a range where platinum surface oxidation and dissolution is likely to occur. The behavior of V e(t  =  20 ms) over a range of electrode surface areas studied was consistent with our sulfuric acid study. Implicit, but little noticed, in Shannon’s formulation is that small and large platinum electrodes behave the same in terms of k value; our data supports this idea. Significance. We hypothesize that the k  =  1.75 Shannon limit for safe stimulation designates a charge-injection boundary above which platinum toxicity becomes a relevant consideration for living cells around an electrode, a possibility that can be directly tested, and is a vital step forward in mission (1).

Electron transfer processes occurring on platinum neural stimulating electrodes: pulsing experiments for cathodic-first, charge-balanced, biphasic pulses for 0.566  ⩽  k  ⩽  2.3 in rat subcutaneous tissues.

PubMed

Kumsa, Doe W; Bhadra, Narendra; Hudak, Eric M; Mortimer, J Thomas

2017-10-01

Our mission is twofold: (1) find a way to safely inject more charge through platinum electrodes than the Shannon limit (k  =  1.75) permits and (2) nurture an interest in the neural stimulation community to understand the electron transfer process occurring on neural stimulating electrodes. We report here on measurements of the electrode potential, performed on platinum neural stimulating electrodes in the subcutaneous space of an anesthetized rat under neural stimulation conditions. The results for six platinum electrodes with areas ranging from 0.2 mm 2 to 12.7 mm 2 were similar to prior results in sulfuric acid, except that the measured potentials were shifted negative 0.36 V because of the pH difference between the two media. The anodic 'end' potential, measured at t  =  20 ms after the onset of the biphasic current pulse, was the primary focus of the data collected because previous results had shown that as charge injection crosses the Shannon limit (k  =  1.75), this potential moves into a range where platinum surface oxidation and dissolution is likely to occur. The behavior of V e (t  =  20 ms) over a range of electrode surface areas studied was consistent with our sulfuric acid study. Implicit, but little noticed, in Shannon's formulation is that small and large platinum electrodes behave the same in terms of k value; our data supports this idea. We hypothesize that the k  =  1.75 Shannon limit for safe stimulation designates a charge-injection boundary above which platinum toxicity becomes a relevant consideration for living cells around an electrode, a possibility that can be directly tested, and is a vital step forward in mission (1).

Efficacy, tolerability and consumer acceptability of terbinafine topical spray versus terbinafine topical solution: a phase IIa, randomised, observer-blind, comparative study.

PubMed

Brown, Marc; Evans, Charles; Muddle, Andrew; Turner, Rob; Lim, Sian; Reed, Jessica; Traynor, Matt

2013-10-01

Tinea pedis is one of the world's most prevalent dermatophyte infections. MedSpray™ tinea pedis 1 % w/w (topical spray) is a novel, easy-to-use propellant-based spray formulation containing 1 % w/w terbinafine, requiring no manipulation at the site of infection. This is in contrast to the only formulation currently approved in Europe for single application (none are approved in the USA for single use), which is Lamisil(®) Once 1 % w/w (topical solution), containing 1 % w/w terbinafine hydrochloride, which requires manipulation on the affected area. The aim of this study was to evaluate the efficacy, tolerability and consumer acceptability of a topical spray versus a topical solution in the treatment of tinea pedis. This study is a phase IIa, randomised, observer-blind, non-inferiority comparative study of the topical spray compared with the topical solution over a 12-week study period. The study was conducted at Bioskin GmbH, Hamburg and Berlin. Patients (n = 120) who presented with the presence of interdigital tinea pedis caused by dermatophytes on one or both feet were enrolled in the study. Patients were randomly assigned between the two treatment groups. Either the topical spray or the topical solution was administered by the study nurse and consisted of a single application (equivalent to 20 mg of terbinafine per foot) on day 1 of the study. No further applications were made for the duration of the study. The hypothesis formulated before commencement of the study was that the topical spray would prove to be non-inferior to the topical solution. Efficacy assessments, including clinical signs and symptoms, mycology and microscopy were performed at baseline and 1, 6 and 12 weeks after treatment. The rate of mycological cure at week 1 was statistically equivalent for both treatments. There was a significant reduction in the overall clinical score as assessed by the Physician's Global Assessment of signs and symptoms for both treatment groups. The topical spray and the topical solution showed comparable anti-fungal activity. Furthermore, the non-inferiority of topical spray to the topical solution was confirmed as determined by the proportion of patients categorised as successfully treated at week 1. This confirms that a topical spray product, which can be applied once without touching the affected skin, is equally as effective in the treatment of tinea pedis and removes the risk of organism transfer associated with touching infected areas. EudraCT-No. 2008-002399-92.

Absorbing film assisted laser induced forward transfer of fungi (Trichoderma conidia)

NASA Astrophysics Data System (ADS)

Hopp, B.; Smausz, T.; Antal, Zs.; Kresz, N.; Bor, Zs.; Chrisey, D.

2004-09-01

We present an investigation on absorbing film assisted laser induced forward transfer (AFA-LIFT) of fungus (Trichoderma) conidia. A KrF excimer laser beam [λ =248nm,FWHM=30ns (FWHM, full width at half maximum)] was directed through a quartz plate and focused onto its silver coated surface where conidia of the Trichoderma strain were uniformly spread. The laser fluence was varied in the range of 0-2600mJ/cm2 and each laser pulse transferred a pixel of target material. The average irradiated area was 8×10-2mm2. After the transfer procedure, the yeast extract medium covered glass slide and the transferred conidia patterns were incubated for 20 h and then observed using an optical microscope. The transferred conidia pixels were germinated and the areas of the culture medium surfaces covered by the pixels were evaluated as a function of laser fluence. As the laser fluence was increased from 0 to 355mJ/cm2 the transferred and germinated pixel area increased from 0 to 0.25mm2. Further increase in fluence resulted in a drastic decrease down to an approximately constant value of 0.06mm2. The yield of successful transfer by AFA-LIFT and germination was as much as 75% at 355mJ/cm2. The results prove that AFA-LIFT can successfully be applied for the controlled transfer of biological objects.

Pharmacokinetics and bioequivalence study of a fixed dose combination of rabeprazole and itopride in healthy Indian volunteers.

PubMed

Sahoo, Bijay Kumar; Das, Ayan; Agarwal, Sangita; Bhaumik, Uttam; Bose, Anirbandeep; Ghosh, Debotri; Roy, Bikash; Pal, Tapan Kumar

2009-01-01

The aim of the present study was to compare the pharmacokinetics of rabeprazole (CAS 117976-89-3) and itopride (CAS 122898-67-3) after oral administration of a rabeprazole (20 mg)-itopride (150 mg) fixed dose combination (FDC) in healthy human volunteers. The bioequivalence of two formulations (test and reference) was determined in 12 healthy Indian male volunteers (age: 25.25 +/- 4.69 years; weight: 60.50 +/- 5.04 kg) in a randomized, single-dose, two-period, two-treatment crossover study. Both formulations were administered orally as a single dose, with the treatments separated by a washout period of 1 week. Rabeprazole and itopride plasma levels were determined by a validated HPLC method using UV detection. The formulations were compared using the pharmacokinetic parameters area under the plasma concentration-time curve (AUC(0-t)), area under the plasma concentration-time curve from zero to infinity (AUC(0-infinity)) and peak plasma concentration (Cmax). General linear model (GLM) procedures were used in which sources of variation were subject, treatment and period. The results indicated that there were no statistically significant differences (P > 0.05) between the logarithmically transformed AUC(0-infinity) and Cmax values between test and reference formulation. The 90% confidence interval for the ratio of the logarithmically transformed AUC(0-t), AUC(0-infinity) and Cmax were within the bioequivalence limits of 0.8-1.25 and the relative bioavailability of rabeprazole and itopride test and reference formulations was 98.24 and 93.65%, respectively.

A Comparative Pharmacokinetics Study of the Anti-Parkinsonian Drug Pramipexole.

PubMed

Putri, Ratih S I; Setiawati, Effi; Aziswan, Syifa A; Ong, Fenny; Tjandrawinata, Raymond R; Susanto, Liana W

2016-11-18

The present study aimed to compare pharmacokinetic parameters of two pramipexole 0.25 mg formulations in order to show bioequivalence. The study was conducted in a randomized, open-label, two-period, two-sequence, and crossover design, involving 23 healthy volunteers. One of the 0.25 mg formulations of pramipexole evaluated in the study was manufactured by PT Dexa Medica, Palembang, Indonesia, the other, used as the reference, by Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim am Rhein, Germany. All eligible subjects were required to fast before each drug administration period, which was separated by a one-week washout period. Pramipexole concentrations in plasma were assayed using a validated ultra performance liquid chromatography with mass spectrometry (UPLC-MS/MS) detector. The evaluated pharmacokinetic parameters included the area under the plasma concentration curve from time zero to the last observed measurable concentration (AUC 0-t ), the area under the plasma concentration curve extrapolated to infinite time (AUC 0-∞ ), the maximum plasma concentration (C max ), the time to reach C max (t max ), and the plasma concentration half-life (t 1/2 ). To evaluate the bioequivalence of those two pramipexole formulations, 90% confidence intervals (CIs) for geometric mean ratios of both formulations were calculated for AUC and C max parameters, while t max and t 1/2 differences were analyzed on the non-transformed data using Wilcoxon matched-pairs and a Student's paired t -test, respectively. The 90% CIs for the geometric mean ratios of the two pramipexole formulations were 95.89% (90.73%-101.34%), 95.53% (89.75%-101.68%), and 92.11% (84.35%-100.58%) for AUC 0-t , AUC 0-∞ , and C max , respectively. There were no statistically significant differences for t max and t 1/2 between the two pramipexole formulations. It is concluded that two pramipexole formulations in this study were bioequivalent.

A Comparative Pharmacokinetics Study of the Anti-Parkinsonian Drug Pramipexole

PubMed Central

Putri, Ratih S. I.; Setiawati, Effi; Aziswan, Syifa A.; Ong, Fenny; Tjandrawinata, Raymond R.; Susanto, Liana W.

2016-01-01

The present study aimed to compare pharmacokinetic parameters of two pramipexole 0.25 mg formulations in order to show bioequivalence. The study was conducted in a randomized, open-label, two-period, two-sequence, and crossover design, involving 23 healthy volunteers. One of the 0.25 mg formulations of pramipexole evaluated in the study was manufactured by PT Dexa Medica, Palembang, Indonesia, the other, used as the reference, by Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim am Rhein, Germany. All eligible subjects were required to fast before each drug administration period, which was separated by a one-week washout period. Pramipexole concentrations in plasma were assayed using a validated ultra performance liquid chromatography with mass spectrometry (UPLC-MS/MS) detector. The evaluated pharmacokinetic parameters included the area under the plasma concentration curve from time zero to the last observed measurable concentration (AUC0-t), the area under the plasma concentration curve extrapolated to infinite time (AUC0-∞), the maximum plasma concentration (Cmax), the time to reach Cmax (tmax), and the plasma concentration half-life (t1/2). To evaluate the bioequivalence of those two pramipexole formulations, 90% confidence intervals (CIs) for geometric mean ratios of both formulations were calculated for AUC and Cmax parameters, while tmax and t1/2 differences were analyzed on the non-transformed data using Wilcoxon matched-pairs and a Student’s paired t-test, respectively. The 90% CIs for the geometric mean ratios of the two pramipexole formulations were 95.89% (90.73%–101.34%), 95.53% (89.75%–101.68%), and 92.11% (84.35%–100.58%) for AUC0-t, AUC0-∞, and Cmax, respectively. There were no statistically significant differences for tmax and t1/2 between the two pramipexole formulations. It is concluded that two pramipexole formulations in this study were bioequivalent. PMID:27869754

Transfer cell wall ingrowths and vein loading characteristics in pea leaf discs. [Pisum sativum

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

Wimmers, L.E.; Turgeon, R.

1987-04-01

Transfer cell wall ingrowths are thought to increase transport capacity by increasing plasmalemma surface area. Leaf minor vein phloem transfer cells presumably enhance phloem loading. In Pisum sativum cv. Little marvel grown under different light regimes (150 to 1000 ..mu..mol photons m/sup -2/ sec/sup -1/) there is a positive correlation between light intensity and wall ingrowth area in phloem transfer cells. The extent of ingrowth and correlation to light intensity is greatest in minor veins, decreasing as vein size increases. Vein loading was assayed by floating abraded leaf discs on /sup 14/C-sucrose (10 mM). There is a positive correlation betweenmore » uptake and transfer cell wall area, although the latter increased more than the former. The difference in uptake is stable throughout the photoperiod, and is also stable in mature leaves for at least four days after plants are transfered to a different light intensity. Sucrose uptake is biphasic. The saturable component of uptake is sensitive to light intensity, the Km for sucrose is negatively correlated to light intensity, while V/sub max/remains unchanged.« less

Channelling information flows from observation to decision; or how to increase certainty

NASA Astrophysics Data System (ADS)

Weijs, S. V.

2015-12-01

To make adequate decisions in an uncertain world, information needs to reach the decision problem, to enable overseeing the full consequences of each possible decision.On its way from the physical world to a decision problem, information is transferred through the physical processes that influence the sensor, then through processes that happen in the sensor, through wires or electromagnetic waves. For the last decade, most information becomes digitized at some point. From moment of digitization, information can in principle be transferred losslessly. Information about the physical world is often also stored, sometimes in compressed form, such as physical laws, concepts, or models of specific hydrological systems. It is important to note, however, that all information about a physical system eventually has to originate from observation (although inevitably coloured by some prior assumptions). This colouring makes the compression lossy, but is effectively the only way to make use of similarities in time and space that enable predictions while measuring only a a few macro-states of a complex hydrological system.Adding physical process knowledge to a hydrological model can thus be seen as a convenient way to transfer information from observations from a different time or place, to make predictions about another situation, assuming the same dynamics are at work.The key challenge to achieve more certainty in hydrological prediction can therefore be formulated as a challenge to tap and channel information flows from the environment. For tapping more information flows, new measurement techniques, large scale campaigns, historical data sets, and large sample hydrology and regionalization efforts can bring progress. For channelling the information flows with minimum loss, model calibration, and model formulation techniques should be critically investigated. Some experience from research in a Swiss high alpine catchment are used as an illustration.

Students' Misconceptions about Heat Transfer Mechanisms and Elementary Kinetic Theory

ERIC Educational Resources Information Center

Pathare, S. R.; Pradhan, H. C.

2010-01-01

Heat and thermodynamics is a conceptually rich area of undergraduate physics. In the Indian context in particular there has been little work done in this area from the point of view of misconceptions. This prompted us to undertake a study in this area. We present a study of students' misconceptions about heat transfer mechanisms, i.e. conduction,…

Numerical simulation of steady three-dimensional flows in axial turbomachinery bladerows

NASA Astrophysics Data System (ADS)

Basson, Anton Herman

The formulation for and application of a numerical model for low Mach number steady three-dimensional flows in axial turbomachinery blade rows is presented. The formulation considered here includes an efficient grid generation scheme (particularly suited to computational grids for the analysis of turbulent turbomachinery flows) and a semi-implicit, pressure-based computational fluid dynamics scheme that directly includes artificial dissipation, applicable to viscous and inviscid flows. The grid generation technique uses a combination of algebraic and elliptic methods, in conjunction with the Minimal Residual Method, to economically generate smooth structured grids. For typical H-grids in turbomachinery bladerows, when compared to a purely elliptic grid generation scheme, the presented grid generation scheme produces grids with much improved smoothness near the leading and trailing edges, allows the use of small near wall grid spacing required by low Reynolds number turbulence models, and maintains orthogonality of the grid near the solid boundaries even for high flow angle cascades. A specialized embedded H-grid for application particularly to tip clearance flows is presented. This topology smoothly discretizes the domain without modifying the tip shape, while requiring only minor modifications to H-grid flow solvers. Better quantitative modeling of the tip clearance vortex structure than that obtained with a pinched tip approximation is demonstrated. The formulation of artificial dissipation terms for a semi-implicit, pressure-based (SIMPLE type) flow solver, is presented. It is applied to both the Euler and the Navier-Stokes equations, expressed in generalized coordinates using a non-staggered grid. This formulation is compared to some SIMPLE and time marching formulations, revealing the artificial dissipation inherent in some commonly used semi-implicit formulations. The effect of the amount of dissipation on the accuracy of the solution and the convergence rate is quantitatively demonstrated for a number of flow cases. The ability of the formulation to model complex steady turbomachinery flows is demonstrated, e.g. for pressure driven secondary flows, turbine nozzle wakes, turbulent boundary layers. The formulation's modeling of blade surface heat transfer is assessed. The numerical model is used to investigate the structure of phenomena associated with tip clearance flows in a turbine nozzle.

Incorporation of 2,4,6-trinitrotoluene (TNT) transforming bacteria into explosive formulations.

PubMed

Nyanhongo, G S; Aichernig, N; Ortner, M; Steiner, Walter; Guebitz, G M

2009-06-15

Pseudomonas putida GG04 and Bacillus SF have been successfully incorporated into an explosive formulation to enhance biotransformation of TNT residues and/or explosives which fail to detonate due to technical faults. The incorporation of the microorganisms into the explosive did not affect the quality of the explosive (5 years storage) in terms of detonation velocity while complete biotransformation of TNT moieties upon transfer in liquid media was observed after 5 days. The incorporated microorganisms reduced TNT sequentially leading to the formation of hydroxylaminodinitrotoluenes (HADNT), 4-amino-2,6-dinitrotoluenes; 2-amino-4,6-dinitrotoluenes, different azoxy compounds; 2,6-diaminonitrotoluenes (2,4-DAMNT) and 2,4-diaminonitrotoluenes (2,6-DAMNT). However, the accumulation of AMDNT and DAMNT (major dead-end metabolites) was effectively prevented by incorporating guaiacol and catechol during the biotransformation process.

Analysis of Flame Deflector Spray Nozzles in Rocket Engine Test Stands

NASA Technical Reports Server (NTRS)

Sachdev, Jai S.; Ahuja, Vineet; Hosangadi, Ashvin; Allgood, Daniel C.

2010-01-01

The development of a unified tightly coupled multi-phase computational framework is described for the analysis and design of cooling spray nozzle configurations on the flame deflector in rocket engine test stands. An Eulerian formulation is used to model the disperse phase and is coupled to the gas-phase equations through momentum and heat transfer as well as phase change. The phase change formulation is modeled according to a modified form of the Hertz-Knudsen equation. Various simple test cases are presented to verify the validity of the numerical framework. The ability of the methodology to accurately predict the temperature load on the flame deflector is demonstrated though application to an actual sub-scale test facility. The CFD simulation was able to reproduce the result of the test-firing, showing that the spray nozzle configuration provided insufficient amount of cooling.

Transient analysis of a thermal storage unit involving a phase change material

NASA Technical Reports Server (NTRS)

Griggs, E. I.; Pitts, D. R.; Humphries, W. R.

1974-01-01

The transient response of a single cell of a typical phase change material type thermal capacitor has been modeled using numerical conductive heat transfer techniques. The cell consists of a base plate, an insulated top, and two vertical walls (fins) forming a two-dimensional cavity filled with a phase change material. Both explicit and implicit numerical formulations are outlined. A mixed explicit-implicit scheme which treats the fin implicity while treating the phase change material explicitly is discussed. A band algorithmic scheme is used to reduce computer storage requirements for the implicit approach while retaining a relatively fine grid. All formulations are presented in dimensionless form thereby enabling application to geometrically similar problems. Typical parametric results are graphically presented for the case of melting with constant heat input to the base of the cell.

A Workshop on the Gathering of Information for Problem Formulation

DTIC Science & Technology

1991-06-01

the Al specialists is to design "artificially intelligent" computer environments that tutor students in much the same way that a human teacher might...tuning the interface betweeen student and machine, and are using a technique of in situ development to tune the system towaid realistic user needs. 141...of transferability to new domains, while the latter suffers from extreme fragility: the inability to cope with any input not strictly conforming with

Managing to Payroll: An Evaluation of Local Activity Data Management

DTIC Science & Technology

1989-06-01

of the long, complex formulation process from line manager input to receipt of payroll authority - serves only as a starting...information from T/ A and labor cards may be input into a locally managed data base before these cards are returned to the FIPC at the end of a pay period...support future labor mix and utilization decisions. Data from the detailed reports is manually transferred to the fourth PC. Another operator using

EC-92: Catalyst for Change

DTIC Science & Technology

1991-04-02

rules of membership and meet the prevailing democratic and judicial standards of the other member states. 16 While only two years ago this possibility...EES/EEA rules affect everyone, not just the EC, then all participants require a role in formulating and accepting the rules . The EC counters that...18 stabilized; members must accept binding rules for the transfer of monetary pol icy to the new bank .34 The most probable shape of the Eurofed, as

Themes on circulation in the third world.

PubMed

Chapman, M; Prothero, R M

1983-01-01

"This article focuses upon circulation, or reciprocal flows of people, with specific reference to Third World societies." Aspects considered include attempts to standardize terminology and to formulate typologies of population movement; the development of explanatory models of circulation and modernization, social networks, family welfare, and capitalism; and "the transfer of methods and concepts to societies and populations different from those from which they initially evolved and in which they were first tested." excerpt

On chirality transfer in electron donor-acceptor complexes. A prediction for the sulfinimine···BF3 system.

PubMed

Rode, Joanna E; Dobrowolski, Jan Cz

2012-01-01

Stabilization energies of the electron donor-acceptor sulfinimine···BF(3) complexes calculated at either the B3LYP/aug-cc-pVTZ or the MP2/aug-cc-pVTZ level do not allow to judge, whether the N- or O-atom in sulfinimine is stronger electron-donor to BF(3) . The problem seems to be solvable because chirality transfer phenomenon between chiral sulfinimine and achiral BF(3) is expected to be vibrational circular dichroism (VCD) active. Moreover, the bands associated with the achiral BF(3) molecule are predicted to be the most intense in the entire spectrum. However, the VCD band robustness analyses show that most of the chirality transfer modes of BF(3) are unreliable. Conversely, variation of VCD intensity with change of intermolecular distance, angle, and selected dihedrals between the complex partners shows that to establish the robustness of chirality transfer mode. It is also necessary to determine the influence of the potential energy surface (PES) shape on the VCD intensity. At the moment, there is still no universal criterion for the chirality transfer mode robustness and the conclusions formulated based on one system cannot be directly transferred even to a quite similar one. However, it is certain that more attention should be focused on relation of PES shape and the VCD mode robustness problem. Copyright © 2011 Wiley Periodicals, Inc.

Gaze transfer in remote cooperation: is it always helpful to see what your partner is attending to?

PubMed

Müller, Romy; Helmert, Jens R; Pannasch, Sebastian; Velichkovsky, Boris M

2013-01-01

Establishing common ground in remote cooperation is challenging because nonverbal means of ambiguity resolution are limited. In such settings, information about a partner's gaze can support cooperative performance, but it is not yet clear whether and to what extent the abundance of information reflected in gaze comes at a cost. Specifically, in tasks that mainly rely on spatial referencing, gaze transfer might be distracting and leave the partner uncertain about the meaning of the gaze cursor. To examine this question, we let pairs of participants perform a joint puzzle task. One partner knew the solution and instructed the other partner's actions by (1) gaze, (2) speech, (3) gaze and speech, or (4) mouse and speech. Based on these instructions, the acting partner moved the pieces under conditions of high or low autonomy. Performance was better when using either gaze or mouse transfer compared to speech alone. However, in contrast to the mouse, gaze transfer induced uncertainty, evidenced in delayed responses to the cursor. Also, participants tried to resolve ambiguities by engaging in more verbal effort, formulating more explicit object descriptions and fewer deictic references. Thus, gaze transfer seems to increase uncertainty and ambiguity, thereby complicating grounding in this spatial referencing task. The results highlight the importance of closely examining task characteristics when considering gaze transfer as a means of support.

Influence of the wetting state of a heated surface on heat transfer and pressure loss in an evaporator tube

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

Koehler, W; Hein, D

1986-09-01

The influence of the wetting state of a heated surface on heat transfer and pressure loss in an evaporator tube was investigated for a parameter range occurring in fossil-fired steam generators. Included in the analysis are quantities which determine the wetting state in steady and transient flow. The experimental work consists of the following: Occurrence of critical heat flux (CHF) and post-CHF heat transfer in a vertical upflow evaporator tube; influence of pressure and enthalpy transients on heat transfer in the unwetted region; influence of pipe orientation on heat transfer; and two phase flow pressure loss in wetted and unwettedmore » region. Based on these experiments a method of predicting CHF for a vertical upflow evaporator tube was developed. The heat transfer in the unwetted region was newly formulated taking into account thermal nonequilibrium between the water and steam phases. Wall temperature excursions during pressure and enthalpy transients are interpreted with the help of the boiling curve and the Leidenfrost phenomenon. A method is developed by means of which it is possible to determine the influence of the pipe orientation on the location of the boiling crisis as well as on the heat transfer in the unwetted region. The influence of the wetting state of the heated surface on the two phase flow pressure loss is interpreted as ''Wall effect'' and is calculated using a simplified computer model. 68 refs., 83 figs.« less

A New Method for 3D Radiative Transfer with Adaptive Grids

NASA Astrophysics Data System (ADS)

Folini, D.; Walder, R.; Psarros, M.; Desboeufs, A.

2003-01-01

We present a new method for 3D NLTE radiative transfer in moving media, including an adaptive grid, along with some test examples and first applications. The central features of our approach we briefly outline in the following. For the solution of the radiative transfer equation, we make use of a generalized mean intensity approach. In this approach, the transfer eqation is solved directly, instead of using the moments of the transfer equation, thus avoiding the associated closure problem. In a first step, a system of equations for the transfer of each directed intensity is set up, using short characteristics. Next, the entity of systems of equations for each directed intensity is re-formulated in the form of one system of equations for the angle-integrated mean intensity. This system then is solved by a modern, fast BiCGStab iterative solver. An additional advantage of this procedure is that convergence rates barely depend on the spatial discretization. For the solution of the rate equations we use Housholder transformations. Lines are treated by a 3D generalization of the well-known Sobolev-approximation. The two parts, solution of the transfer equation and solution of the rate equations, are iteratively coupled. We recently have implemented an adaptive grid, which allows for recursive refinement on a cell-by-cell basis. The spatial resolution, which is always a problematic issue in 3D simulations, we can thus locally reduce or augment, depending on the problem to be solved.

Cooperative Drought Adaptation: Integrating Infrastructure Development, Conservation, and Water Transfers into Adaptive Policy Pathways

NASA Astrophysics Data System (ADS)

Zeff, H. B.; Characklis, G. W.; Reed, P. M.; Herman, J. D.

2015-12-01

Water supply policies that integrate portfolios of short-term management decisions with long-term infrastructure development enable utilities to adapt to a range of future scenarios. An effective mix of short-term management actions can augment existing infrastructure, potentially forestalling new development. Likewise, coordinated expansion of infrastructure such as regional interconnections and shared treatment capacity can increase the effectiveness of some management actions like water transfers. Highly adaptable decision pathways that mix long-term infrastructure options and short-term management actions require decision triggers capable of incorporating the impact of these time-evolving decisions on growing water supply needs. Here, we adapt risk-based triggers to sequence a set of potential infrastructure options in combination with utility-specific conservation actions and inter-utility water transfers. Individual infrastructure pathways can be augmented with conservation or water transfers to reduce the cost of meeting utility objectives, but they can also include cooperatively developed, shared infrastructure that expands regional capacity to transfer water. This analysis explores the role of cooperation among four water utilities in the 'Research Triangle' region of North Carolina by formulating three distinct categories of adaptive policy pathways: independent action (utility-specific conservation and supply infrastructure only), weak cooperation (utility-specific conservation and infrastructure development with regional transfers), and strong cooperation (utility specific conservation and jointly developed of regional infrastructure that supports transfers). Results suggest that strong cooperation aids the utilities in meeting their individual objections at substantially lower costs and with fewer irreversible infrastructure options.

What Can Other Areas Teach Us about Numeracy?

ERIC Educational Resources Information Center

Ferme, Elizabeth

2014-01-01

Education professionals, regardless of their specialist area, are broadly aware of the importance of numeracy. Internationally, definitions of numeracy (known elsewhere as mathematical literacy or quantitative reasoning), describe "an individual's capacity to formulate, employ and interpret mathematics in a variety of contexts... reasoning…

The First International Biosphere Reserve Congress.

ERIC Educational Resources Information Center

Laird, John

1984-01-01

Presents objectives (and related activities) of a plan designed for international collaboration in conserving key natural areas (biosphere reserves) of the globe. The plan (focusing on such areas as management, conservation, research, monitoring, and environmental education/training) was formulated during the First International Biosphere Reserve…