Accuracy of tree diameter estimation from terrestrial laser scanning by circle-fitting methods

NASA Astrophysics Data System (ADS)

Koreň, Milan; Mokroš, Martin; Bucha, Tomáš

2017-12-01

This study compares the accuracies of diameter at breast height (DBH) estimations by three initial (minimum bounding box, centroid, and maximum distance) and two refining (Monte Carlo and optimal circle) circle-fitting methods The circle-fitting algorithms were evaluated in multi-scan mode and a simulated single-scan mode on 157 European beech trees (Fagus sylvatica L.). DBH measured by a calliper was used as reference data. Most of the studied circle-fitting algorithms significantly underestimated the mean DBH in both scanning modes. Only the Monte Carlo method in the single-scan mode significantly overestimated the mean DBH. The centroid method proved to be the least suitable and showed significantly different results from the other circle-fitting methods in both scanning modes. In multi-scan mode, the accuracy of the minimum bounding box method was not significantly different from the accuracies of the refining methods The accuracy of the maximum distance method was significantly different from the accuracies of the refining methods in both scanning modes. The accuracy of the Monte Carlo method was significantly different from the accuracy of the optimal circle method in only single-scan mode. The optimal circle method proved to be the most accurate circle-fitting method for DBH estimation from point clouds in both scanning modes.

High resolution melting analysis: rapid and precise characterisation of recombinant influenza A genomes

PubMed Central

2013-01-01

Background High resolution melting analysis (HRM) is a rapid and cost-effective technique for the characterisation of PCR amplicons. Because the reverse genetics of segmented influenza A viruses allows the generation of numerous influenza A virus reassortants within a short time, methods for the rapid selection of the correct recombinants are very useful. Methods PCR primer pairs covering the single nucleotide polymorphism (SNP) positions of two different influenza A H5N1 strains were designed. Reassortants of the two different H5N1 isolates were used as a model to prove the suitability of HRM for the selection of the correct recombinants. Furthermore, two different cycler instruments were compared. Results Both cycler instruments generated comparable average melting peaks, which allowed the easy identification and selection of the correct cloned segments or reassorted viruses. Conclusions HRM is a highly suitable method for the rapid and precise characterisation of cloned influenza A genomes. PMID:24028349

Interplay of symmetries and other integrability quantifiers in finite-dimensional integrable nonlinear dynamical systems

PubMed Central

Mohanasubha, R.; Chandrasekar, V. K.; Lakshmanan, M.

2016-01-01

In this work, we establish a connection between the extended Prelle–Singer procedure and other widely used analytical methods to identify integrable systems in the case of nth-order nonlinear ordinary differential equations (ODEs). By synthesizing these methods, we bring out the interlink between Lie point symmetries, contact symmetries, λ-symmetries, adjoint symmetries, null forms, Darboux polynomials, integrating factors, the Jacobi last multiplier and generalized λ-symmetries corresponding to the nth-order ODEs. We also prove these interlinks with suitable examples. By exploiting these interconnections, the characteristic quantities associated with different methods can be deduced without solving the associated determining equations. PMID:27436964

Interpreter composition issues in the formal verification of a processor-memory module

NASA Technical Reports Server (NTRS)

Fura, David A.; Cohen, Gerald C.

1994-01-01

This report describes interpreter composition techniques suitable for the formal specification and verification of a processor-memory module using the HOL theorem proving system. The processor-memory module is a multichip subsystem within a fault-tolerant embedded system under development within the Boeing Defense and Space Group. Modeling and verification methods were developed that permit provably secure composition at the transaction-level of specification, significantly reducing the complexity of the hierarchical verification of the system.

Some Inspection Methods for Quality Control and In-service Inspection of GLARE

NASA Astrophysics Data System (ADS)

Sinke, J.

2003-07-01

Quality control of materials and structures is an important issue, also for GLARE. During the manufacturing stage the processes and materials should be monitored and checked frequently in order to obtain a qualified product. During the operation of the aircraft, frequent monitoring and inspections are performed to maintain the quality at a prescribed level. Therefore, in-service inspection methods are applied, and when necessary repair activities are conducted. For the quality control of the GLARE panels and components during manufacturing, the C-scan method proves to be an effective tool. For in-service inspection the Eddy Current Method is one of the suitable options. In this paper a brief overview is presented of both methods and their application on GLARE products.

Geometric constrained variational calculus. II: The second variation (Part I)

NASA Astrophysics Data System (ADS)

Massa, Enrico; Bruno, Danilo; Luria, Gianvittorio; Pagani, Enrico

2016-10-01

Within the geometrical framework developed in [Geometric constrained variational calculus. I: Piecewise smooth extremals, Int. J. Geom. Methods Mod. Phys. 12 (2015) 1550061], the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A fully covariant representation of the second variation of the action functional, based on a suitable gauge transformation of the Lagrangian, is explicitly worked out. Both necessary and sufficient conditions for minimality are proved, and reinterpreted in terms of Jacobi fields.

Suitable Site Selection of Small Dams Using Geo-Spatial Technique: a Case Study of Dadu Tehsil, Sindh

NASA Astrophysics Data System (ADS)

Khalil, Zahid

2016-07-01

Decision making about identifying suitable sites for any project by considering different parameters, is difficult. Using GIS and Multi-Criteria Analysis (MCA) can make it easy for those projects. This technology has proved to be an efficient and adequate in acquiring the desired information. In this study, GIS and MCA were employed to identify the suitable sites for small dams in Dadu Tehsil, Sindh. The GIS software is used to create all the spatial parameters for the analysis. The parameters that derived are slope, drainage density, rainfall, land use / land cover, soil groups, Curve Number (CN) and runoff index with a spatial resolution of 30m. The data used for deriving above layers include 30 meter resolution SRTM DEM, Landsat 8 imagery, and rainfall from National Centre of Environment Prediction (NCEP) and soil data from World Harmonized Soil Data (WHSD). Land use/Land cover map is derived from Landsat 8 using supervised classification. Slope, drainage network and watershed are delineated by terrain processing of DEM. The Soil Conservation Services (SCS) method is implemented to estimate the surface runoff from the rainfall. Prior to this, SCS-CN grid is developed by integrating the soil and land use/land cover raster. These layers with some technical and ecological constraints are assigned weights on the basis of suitability criteria. The pair wise comparison method, also known as Analytical Hierarchy Process (AHP) is took into account as MCA for assigning weights on each decision element. All the parameters and group of parameters are integrated using weighted overlay in GIS environment to produce suitable sites for the Dams. The resultant layer is then classified into four classes namely, best suitable, suitable, moderate and less suitable. This study reveals a contribution to decision making about suitable sites analysis for small dams using geo-spatial data with minimal amount of ground data. This suitability maps can be helpful for water resource management organizations in determination of feasible rainwater harvesting structures (RWH).

The Systematic Development of an Internet-Based Smoking Cessation Intervention for Adults.

PubMed

Dalum, Peter; Brandt, Caroline Lyng; Skov-Ettrup, Lise; Tolstrup, Janne; Kok, Gerjo

2016-07-01

Objectives The objective of this project was to determine whether intervention mapping is a suitable strategy for developing an Internet- and text message-based smoking cessation intervention. Method We used the Intervention Mapping framework for planning health promotion programs. After a needs assessment, we identified important changeable determinants of cessation behavior, specified objectives for the intervention, selected theoretical methods for meeting our objectives, and operationalized change methods into practical intervention strategies. Results We found that "social cognitive theory," the "transtheoretical model/stages of change," "self-regulation theory," and "appreciative inquiry" were relevant theories for smoking cessation interventions. From these theories, we selected modeling/behavioral journalism, feedback, planning coping responses/if-then statements, gain frame/positive imaging, consciousness-raising, helping relationships, stimulus control, and goal-setting as suitable methods for an Internet- and text-based adult smoking cessation program. Furthermore, we identified computer tailoring as a useful strategy for adapting the intervention to individual users. Conclusion The Intervention Mapping method, with a clear link between behavioral goals, theoretical methods, and practical strategies and materials, proved useful for systematic development of a digital smoking cessation intervention for adults. © 2016 Society for Public Health Education.

A study of different indicators of Maillard reaction with whey proteins and different carbohydrates under adverse storage conditions.

PubMed

Leiva, Graciela E; Naranjo, Gabriela B; Malec, Laura S

2017-01-15

This study examined different indicators of each stage of Maillard reaction under adverse storage conditions in a system with whey proteins and lactose or glucose. The analysis of lysine loss by the o-phthaldialdehyde method can be considered a good indicator of the early stage, showing considerable differences in reactivity when systems with mono and disaccharides were analyzed. Capillary electrophoresis proved to be a sensitive method for evaluating the extent of glycosylation of the native proteins, providing valuable information when the loss of lysine was not significant. The estimation of the Amadori compound from the determination of total 5-hydroxymethyl-2-furfuraldehyde would have correlate well with reactive lysine content if the advanced stages of the reaction had not been reached. For assessing the occurrence of the intermediate and final stages, the measurement of free 5-hydroxymethyl-2-furfuraldehyde and color, proved not to be suitable for storage conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Cauchy Problem in Local Spaces for the Complex Ginzburg-Landau EquationII. Contraction Methods

NASA Astrophysics Data System (ADS)

Ginibre, J.; Velo, G.

We continue the study of the initial value problem for the complex Ginzburg-Landau equation (with a > 0, b > 0, g>= 0) in initiated in a previous paper [I]. We treat the case where the initial data and the solutions belong to local uniform spaces, more precisely to spaces of functions satisfying local regularity conditions and uniform bounds in local norms, but no decay conditions (or arbitrarily weak decay conditions) at infinity in . In [I] we used compactness methods and an extended version of recent local estimates [3] and proved in particular the existence of solutions globally defined in time with local regularity of the initial data corresponding to the spaces Lr for r>= 2 or H1. Here we treat the same problem by contraction methods. This allows us in particular to prove that the solutions obtained in [I] are unique under suitable subcriticality conditions, and to obtain for them additional regularity properties and uniform bounds. The method extends some of those previously applied to the nonlinear heat equation in global spaces to the framework of local uniform spaces.

Application of optical interferometry in focused acoustic field measurement

NASA Astrophysics Data System (ADS)

Wang, Yuebing; Sun, Min; Cao, Yonggang; Zhu, Jiang

2018-07-01

Optical interferometry has been successfully applied in measuring acoustic pressures in plane-wave fields and spherical-wave fields. In this paper, the "effective" refractive index for focused acoustic fields was developed, through numerical simulation and experiments, the feasibility of the optical method in measuring acoustic fields of focused transducers was proved. Compared with the results from a membrane hydrophone, it was concluded that the optical method has good spatial resolution and is suitable for detecting focused fields with fluctuant distributions. The influences of a few factors (the generated lamb wave, laser beam directivity, etc.) were analyzed, and corresponding suggestions were proposed for effective application of this technology.

Determination of tributyltin in environmental water matrices using stir bar sorptive extraction with in-situ derivatisation and large volume injection-gas chromatography-mass spectrometry.

PubMed

Neng, N R; Santalla, R P; Nogueira, J M F

2014-08-01

Stir bar sorptive extraction with in-situ derivatization using sodium tetrahydridoborate (NaBH4) followed by liquid desorption and large volume injection-gas chromatography-mass spectrometry detection under the selected ion monitoring mode (SBSE(NaBH4)in-situ-LD/LVI-GC-MS(SIM)) was successfully developed for the determination of tributyltin (TBT) in environmental water matrices. NaBH4 proved to be an effective and easy in-situ speciation agent for TBT in aqueous media, allowing the formation of adducts with enough stability and suitable polarity for SBSE analysis. Assays performed on water samples spiked at the 10.0μg/L, yielded convenient recoveries (68.2±3.0%), showed good accuracy, suitable precision (RSD<9.0%), low detection limits (23ng/L) and excellent linear dynamic range (r(2)=0.9999) from 0.1 to 170.0µg/L, under optimized experimental conditions. By using the standard addition method, the application of the present methodology to real surface water samples allowed very good performance at the trace level. The proposed methodology proved to be a feasible alternative for routine quality control analysis, easy to implement, reliable and sensitive to monitor TBT in environmental water matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

Proving the suitability of magnetoelectric stimuli for tissue engineering applications.

PubMed

Ribeiro, C; Correia, V; Martins, P; Gama, F M; Lanceros-Mendez, S

2016-04-01

A novel approach for tissue engineering applications based on the use of magnetoelectric materials is presented. This work proves that magnetoelectric Terfenol-D/poly(vinylidene fluoride-co-trifluoroethylene) composites are able to provide mechanical and electrical stimuli to MC3T3-E1 pre-osteoblast cells and that those stimuli can be remotely triggered by an applied magnetic field. Cell proliferation is enhanced up to ≈ 25% when cells are cultured under mechanical (up to 110 ppm) and electrical stimulation (up to 0.115 mV), showing that magnetoelectric cell stimulation is a novel and suitable approach for tissue engineering allowing magnetic, mechanical and electrical stimuli. Copyright © 2015 Elsevier B.V. All rights reserved.

[Continuous subcutaneous morphine--treatment of pain in patients with terminal cancer].

PubMed

Nielsen, F B; Clemensen, S E; Olesen, A S; Hole, P

1990-06-11

Nine patients with terminal cancer were treated for pain with continuous subcutaneous injection of morphine via a portable battery-driven injection pump. Treatment was instituted on account of failure of other forms of treatment with oral or epidural morphine derivatives or on account of severe nausea and vomiting which necessitated parenteral administration. Treatment proved reasonably effective and no side effects of significance occurred. Two of the patients could be treated in their homes. The method is thus considered as suitable for treatment of pain in patients with terminal cancer.

Growth of lead tin telluride crystals in gels

NASA Technical Reports Server (NTRS)

Barber, Patrick G.

1986-01-01

Improved gels and several geometries were investigated for use in growing crystals. The use of lead sulfide test crystals proved workable, but it was impossible to obtain and maintain a sufficiently concentrated telluride ion solution to successfully grow lead telluride crystals. It appears that oxygen in the solution is capable of oxidizing the telluride ion up to tellurium metal. The method may still be successful, but only if precautions are taken to eliminate dissolved oxygen from the gels and aqueous solutions and to maintain a suitable concentration of telluride, Te(2)-(aq.).

Field Application of the Micro Biological Survey Method for the Assessment of the Microbiological Safety of Different Water Sources in Horn of Africa and the Evaluation of the Effectiveness of Moringa Oleifera in Drinking Water Purification

PubMed Central

Losito, Francesca; Arienzo, Alyexandra; Somma, Daniela; Murgia, Lorenza; Stalio, Ottavia; Zuppi, Paolo; Rossi, Elisabetta; Antonini, Giovanni

2017-01-01

Water monitoring requires expensive instrumentations and skilled technicians. In developing Countries as Africa, the severe economic restrictions and lack of technology make water safety monitoring approaches applied in developed Countries, still not sustainable. The need to develop new methods that are suitable, affordable, and sustainable in the African context is urgent. The simple, economic and rapid Micro Biological Survey (MBS) method does not require an equipped laboratory nor special instruments and skilled technicians, but it can be very useful for routine water analysis. The aim of this work was the application of the MBS method to evaluate the microbiological safety of different water sources and the effectiveness of different drinking water treatments in the Horn of Africa. The obtained results have proved that this method could be very helpful to monitor water safety before and after various purification treatments, with the aim to control waterborne diseases especially in developing Countries, whose population is the most exposed to these diseases. In addition, it has been proved that Moringa oleifera water treatment is ineffective in decreasing bacterial load of Eritrea water samples. PMID:28748063

Field Application of the Micro Biological Survey Method for the Assessment of the Microbiological Safety of Different Water Sources in Horn of Africa and the Evaluation of the Effectiveness of Moringa Oleifera in Drinking Water Purification.

PubMed

Losito, Francesca; Arienzo, Alyexandra; Somma, Daniela; Murgia, Lorenza; Stalio, Ottavia; Zuppi, Paolo; Rossi, Elisabetta; Antonini, Giovanni

2017-06-23

Water monitoring requires expensive instrumentations and skilled technicians. In developing Countries as Africa, the severe economic restrictions and lack of technology make water safety monitoring approaches applied in developed Countries, still not sustainable. The need to develop new methods that are suitable, affordable, and sustainable in the African context is urgent. The simple, economic and rapid Micro Biological Survey (MBS) method does not require an equipped laboratory nor special instruments and skilled technicians, but it can be very useful for routine water analysis. The aim of this work was the application of the MBS method to evaluate the microbiological safety of different water sources and the effectiveness of different drinking water treatments in the Horn of Africa. The obtained results have proved that this method could be very helpful to monitor water safety before and after various purification treatments, with the aim to control waterborne diseases especially in developing Countries, whose population is the most exposed to these diseases. In addition, it has been proved that Moringa oleifera water treatment is ineffective in decreasing bacterial load of Eritrea water samples.

Mean Field Type Control with Congestion (II): An Augmented Lagrangian Method

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

Achdou, Yves, E-mail: achdou@ljll.univ-paris-diderot.fr; Laurière, Mathieu

This work deals with a numerical method for solving a mean-field type control problem with congestion. It is the continuation of an article by the same authors, in which suitably defined weak solutions of the system of partial differential equations arising from the model were discussed and existence and uniqueness were proved. Here, the focus is put on numerical methods: a monotone finite difference scheme is proposed and shown to have a variational interpretation. Then an Alternating Direction Method of Multipliers for solving the variational problem is addressed. It is based on an augmented Lagrangian. Two kinds of boundary conditionsmore » are considered: periodic conditions and more realistic boundary conditions associated to state constrained problems. Various test cases and numerical results are presented.« less

Immobilization of horseradish peroxidase on silane-modified ceramics and their properties: potential for oily wastewater treatment.

PubMed

Liu, W; Wang, W C; Li, H S; Zhou, X

2011-01-01

Horseradish peroxidase (HRP) is proved being effective in eliminating oil from aqueous solutions, but the elimination is expensive because free HRP can not be reused. In present work, HRP was successfully immobilized on cordierite porous ceramics support with a novel method of N-beta-aminoethyl-gamma-aminopropyl-trimethoxysilane modification and glutaraldehyde activation. Under the optimized immobilized conditions, the actual immobilized HRP was 1.16 mg/g support, the activity of the immobilized HRP could reach as high as 1379.4 U/g support. Experiment results showed that the properties of storage stability, acid-base stability and the tolerance to the pH fluctuation of the immobilized HRP were better than those of the free HRP. The operation stability of the immobilized HRP was also good. The immobilized HRP is suitable for the oily wastewater treatment because of its reusability proved in this work.

A novel sample preparation method to avoid influence of embedding medium during nano-indentation

NASA Astrophysics Data System (ADS)

Meng, Yujie; Wang, Siqun; Cai, Zhiyong; Young, Timothy M.; Du, Guanben; Li, Yanjun

2013-02-01

The effect of the embedding medium on the nano-indentation measurements of lignocellulosic materials was investigated experimentally using nano-indentation. Both the reduced elastic modulus and the hardness of non-embedded cell walls were found to be lower than those of the embedded samples, proving that the embedding medium used for specimen preparation on cellulosic material during nano-indentation can modify cell-wall properties. This leads to structural and chemical changes in the cell-wall constituents, changes that may significantly alter the material properties. Further investigation was carried out to detect the influence of different vacuum times on the cell-wall mechanical properties during the embedding procedure. Interpretation of the statistical analysis revealed no linear relationships between vacuum time and the mechanical properties of cell walls. The quantitative measurements confirm that low-viscosity resin has a rapid penetration rate early in the curing process. Finally, a novel sample preparation method aimed at preventing resin diffusion into lignocellulosic cell walls was developed using a plastic film to wrap the sample before embedding. This method proved to be accessible and straightforward for many kinds of lignocellulosic material, but is especially suitable for small, soft samples.

Metals removal from aqueous solution by iron-based bonding agents.

PubMed

Deliyanni, Eleni A; Lazaridis, Nikolaos K; Peleka, Efrosini N; Matis, Konstantinos A

2004-01-01

GOAL AND SCOPE AND BACKGROUND: The application of a promising method, termed sorptive flotation, for the removal of chromium(VI) and zinc ions was the aim of the present paper. A special case of sorptive flotation is adsorbing colloid flotation. Suitable sorbent preparation techniques have been developed in the laboratory. Sorptive flotation, consisting of the sorption and flotation processes combined in series, has proved to give fast and satisfactory treatment of the industrial streams and effluents bearing dilute aqueous solutions of zinc and chromium(VI). Goethite has proved to be effective for the removal of chromium(VI) and zinc ions. Also, adsorbing colloid flotation with ferric hydroxide (as the co-precipitant) could be an alternative method to the above-mentioned separation of metal ions. In both cases, chromium(VI) (pH=4) and zinc (pH=7) removal was about 100%. The reasons for selecting the iron-based bonding materials, like goethite and/or in-situ produced ferric hydroxide, are that they are cheap, easily synthesized, suitable both for cation and anion sorption, and, furthermore, that they present low risks for adding a further pollutant to the system. Promising results were obtained. The application of goethite and in-situ produced ferric hydroxide has demonstrated their effectiveness in the removal of heavy metal ions, such as chromium anions and zinc cations. A proposed continuation of current work is the utilization of similar iron oxides, for instance synthesized akaganeite. The comparison between the results reported in this paper with the results reported in the literature, also deserves attention.

On degenerate coupled transport processes in porous media with memory phenomena

NASA Astrophysics Data System (ADS)

Beneš, Michal; Pažanin, Igor

2018-06-01

In this paper we prove the existence of weak solutions to degenerate parabolic systems arising from the fully coupled moisture movement, solute transport of dissolved species and heat transfer through porous materials. Physically relevant mixed Dirichlet-Neumann boundary conditions and initial conditions are considered. Existence of a global weak solution of the problem is proved by means of semidiscretization in time, proving necessary uniform estimates and by passing to the limit from discrete approximations. Degeneration occurs in the nonlinear transport coefficients which are not assumed to be bounded below and above by positive constants. Degeneracies in transport coefficients are overcome by proving suitable a-priori $L^{\\infty}$-estimates based on De Giorgi and Moser iteration technique.

Fictitious domain method for fully resolved reacting gas-solid flow simulation

NASA Astrophysics Data System (ADS)

Zhang, Longhui; Liu, Kai; You, Changfu

2015-10-01

Fully resolved simulation (FRS) for gas-solid multiphase flow considers solid objects as finite sized regions in flow fields and their behaviours are predicted by solving equations in both fluid and solid regions directly. Fixed mesh numerical methods, such as fictitious domain method, are preferred in solving FRS problems and have been widely researched. However, for reacting gas-solid flows no suitable fictitious domain numerical method has been developed. This work presents a new fictitious domain finite element method for FRS of reacting particulate flows. Low Mach number reacting flow governing equations are solved sequentially on a regular background mesh. Particles are immersed in the mesh and driven by their surface forces and torques integrated on immersed interfaces. Additional treatments on energy and surface reactions are developed. Several numerical test cases validated the method and a burning carbon particles array falling simulation proved the capability for solving moving reacting particle cluster problems.

Method to improve the blade tip-timing accuracy of fiber bundle sensor under varying tip clearance

NASA Astrophysics Data System (ADS)

Duan, Fajie; Zhang, Jilong; Jiang, Jiajia; Guo, Haotian; Ye, Dechao

2016-01-01

Blade vibration measurement based on the blade tip-timing method has become an industry-standard procedure. Fiber bundle sensors are widely used for tip-timing measurement. However, the variation of clearance between the sensor and the blade will bring a tip-timing error to fiber bundle sensors due to the change in signal amplitude. This article presents methods based on software and hardware to reduce the error caused by the tip clearance change. The software method utilizes both the rising and falling edges of the tip-timing signal to determine the blade arrival time, and a calibration process suitable for asymmetric tip-timing signals is presented. The hardware method uses an automatic gain control circuit to stabilize the signal amplitude. Experiments are conducted and the results prove that both methods can effectively reduce the impact of tip clearance variation on the blade tip-timing and improve the accuracy of measurements.

Research on Visual Analysis Methods of Terrorism Events

NASA Astrophysics Data System (ADS)

Guo, Wenyue; Liu, Haiyan; Yu, Anzhu; Li, Jing

2016-06-01

Under the situation that terrorism events occur more and more frequency throughout the world, improving the response capability of social security incidents has become an important aspect to test governments govern ability. Visual analysis has become an important method of event analysing for its advantage of intuitive and effective. To analyse events' spatio-temporal distribution characteristics, correlations among event items and the development trend, terrorism event's spatio-temporal characteristics are discussed. Suitable event data table structure based on "5W" theory is designed. Then, six types of visual analysis are purposed, and how to use thematic map and statistical charts to realize visual analysis on terrorism events is studied. Finally, experiments have been carried out by using the data provided by Global Terrorism Database, and the results of experiments proves the availability of the methods.

Metering error quantification under voltage and current waveform distortion

NASA Astrophysics Data System (ADS)

Wang, Tao; Wang, Jia; Xie, Zhi; Zhang, Ran

2017-09-01

With integration of more and more renewable energies and distortion loads into power grid, the voltage and current waveform distortion results in metering error in the smart meters. Because of the negative effects on the metering accuracy and fairness, it is an important subject to study energy metering combined error. In this paper, after the comparing between metering theoretical value and real recorded value under different meter modes for linear and nonlinear loads, a quantification method of metering mode error is proposed under waveform distortion. Based on the metering and time-division multiplier principles, a quantification method of metering accuracy error is proposed also. Analyzing the mode error and accuracy error, a comprehensive error analysis method is presented which is suitable for new energy and nonlinear loads. The proposed method has been proved by simulation.

Comparison Study of Different BOD Tests in the Determination of BOD7 Evaluated in a Model Domestic Sewage

PubMed Central

Roppola, Katri; Kuokkanen, Toivo; Rämö, Jaakko; Prokkola, Hanna; Heiska, Eeva

2007-01-01

The aim of this research was to study the suitability of a manometric respirometric test (OECD 301F) for the determination of biological oxygen demand (BOD) in domestic wastewater. This was done by comparing four different BOD tests (a manometric respirometric test, oxygen sensor determination, iodometric titration, and UV absorption measurement) and by evaluating the BOD7 value after a short-term measurement applying the manometric respirometric test. Measurements were done in three different laboratories. The respirometric test was performed well on municipal sewage, and the precision of results was good. There were minor deviations between BOD7 values as determined by the different methods, but the deviations were not essentially big enough to have a practical impact. Evaluation of the BOD7 value after two or three days' incubation by the respirometric method was shown to work well; average deviations between measured and evaluated values after three days' incubation were 5–18%. Hence, the manometric respirometric test proved to be a rapid and suitable tool for process control purposes. PMID:17671608

Thermoacoustic tomography for an integro-differential wave equation modeling attenuation

NASA Astrophysics Data System (ADS)

Acosta, Sebastián; Palacios, Benjamín

2018-02-01

In this article we study the inverse problem of thermoacoustic tomography (TAT) on a medium with attenuation represented by a time-convolution (or memory) term, and whose consideration is motivated by the modeling of ultrasound waves in heterogeneous tissue via fractional derivatives with spatially dependent parameters. Under the assumption of being able to measure data on the whole boundary, we prove uniqueness and stability, and propose a convergent reconstruction method for a class of smooth variable sound speeds. By a suitable modification of the time reversal technique, we obtain a Neumann series reconstruction formula.

Probability density function of a puff dispersing from the wall of a turbulent channel

NASA Astrophysics Data System (ADS)

Nguyen, Quoc; Papavassiliou, Dimitrios

2015-11-01

Study of dispersion of passive contaminants in turbulence has proved to be helpful in understanding fundamental heat and mass transfer phenomena. Many simulation and experimental works have been carried out to locate and track motions of scalar markers in a flow. One method is to combine Direct Numerical Simulation (DNS) and Lagrangian Scalar Tracking (LST) to record locations of markers. While this has proved to be useful, high computational cost remains a concern. In this study, we develop a model that could reproduce results obtained by DNS and LST for turbulent flow. Puffs of markers with different Schmidt numbers were released into a flow field at a frictional Reynolds number of 150. The point of release was at the channel wall, so that both diffusion and convection contribute to the puff dispersion pattern, defining different stages of dispersion. Based on outputs from DNS and LST, we seek the most suitable and feasible probability density function (PDF) that represents distribution of markers in the flow field. The PDF would play a significant role in predicting heat and mass transfer in wall turbulence, and would prove to be helpful where DNS and LST are not always available.

Preconditioned alternating direction method of multipliers for inverse problems with constraints

NASA Astrophysics Data System (ADS)

Jiao, Yuling; Jin, Qinian; Lu, Xiliang; Wang, Weijie

2017-02-01

We propose a preconditioned alternating direction method of multipliers (ADMM) to solve linear inverse problems in Hilbert spaces with constraints, where the feature of the sought solution under a linear transformation is captured by a possibly non-smooth convex function. During each iteration step, our method avoids solving large linear systems by choosing a suitable preconditioning operator. In case the data is given exactly, we prove the convergence of our preconditioned ADMM without assuming the existence of a Lagrange multiplier. In case the data is corrupted by noise, we propose a stopping rule using information on noise level and show that our preconditioned ADMM is a regularization method; we also propose a heuristic rule when the information on noise level is unavailable or unreliable and give its detailed analysis. Numerical examples are presented to test the performance of the proposed method.

Extracting Objects for Aerial Manipulation on UAVs Using Low Cost Stereo Sensors

PubMed Central

Ramon Soria, Pablo; Bevec, Robert; Arrue, Begoña C.; Ude, Aleš; Ollero, Aníbal

2016-01-01

Giving unmanned aerial vehicles (UAVs) the possibility to manipulate objects vastly extends the range of possible applications. This applies to rotary wing UAVs in particular, where their capability of hovering enables a suitable position for in-flight manipulation. Their manipulation skills must be suitable for primarily natural, partially known environments, where UAVs mostly operate. We have developed an on-board object extraction method that calculates information necessary for autonomous grasping of objects, without the need to provide the model of the object’s shape. A local map of the work-zone is generated using depth information, where object candidates are extracted by detecting areas different to our floor model. Their image projections are then evaluated using support vector machine (SVM) classification to recognize specific objects or reject bad candidates. Our method builds a sparse cloud representation of each object and calculates the object’s centroid and the dominant axis. This information is then passed to a grasping module. Our method works under the assumption that objects are static and not clustered, have visual features and the floor shape of the work-zone area is known. We used low cost cameras for creating depth information that cause noisy point clouds, but our method has proved robust enough to process this data and return accurate results. PMID:27187413

Extracting Objects for Aerial Manipulation on UAVs Using Low Cost Stereo Sensors.

PubMed

Ramon Soria, Pablo; Bevec, Robert; Arrue, Begoña C; Ude, Aleš; Ollero, Aníbal

2016-05-14

Giving unmanned aerial vehicles (UAVs) the possibility to manipulate objects vastly extends the range of possible applications. This applies to rotary wing UAVs in particular, where their capability of hovering enables a suitable position for in-flight manipulation. Their manipulation skills must be suitable for primarily natural, partially known environments, where UAVs mostly operate. We have developed an on-board object extraction method that calculates information necessary for autonomous grasping of objects, without the need to provide the model of the object's shape. A local map of the work-zone is generated using depth information, where object candidates are extracted by detecting areas different to our floor model. Their image projections are then evaluated using support vector machine (SVM) classification to recognize specific objects or reject bad candidates. Our method builds a sparse cloud representation of each object and calculates the object's centroid and the dominant axis. This information is then passed to a grasping module. Our method works under the assumption that objects are static and not clustered, have visual features and the floor shape of the work-zone area is known. We used low cost cameras for creating depth information that cause noisy point clouds, but our method has proved robust enough to process this data and return accurate results.

Approximate study of the free vibrations of a cantilever anisotropic plate carrying a concentrated mass

NASA Astrophysics Data System (ADS)

Ciancio, P. M.; Rossit, C. A.; Laura, P. A. A.

2007-05-01

This study is concerned with the vibration analysis of a cantilevered rectangular anisotropic plate when a concentrated mass is rigidly attached to its center point. Based on the classical theory of anisotropic plates, the Ritz method is employed to perform the analysis. The deflection of the plate is approximated by a set of beam functions in each principal coordinate direction. The influence of the mass magnitude on the natural frequencies and modal shapes of vibration is studied for a boron-epoxy plate and also in the case of a generic anisotropic material. The classical Ritz method with beam functions as the spatial approximation proved to be a suitable procedure to solve a problem of this analytical complexity.

Determination of carbohydrates in medicinal plants--comparison between TLC, mf-MELDI-MS and GC-MS.

PubMed

Qureshi, Muhammad Nasimullah; Stecher, Guenther; Sultana, Tahira; Abel, Gudrun; Popp, Michael; Bonn, Guenther K

2011-01-01

Quality control in the pharmaceutical and phytopharmaceutical industries requires fast and reliable methods for the analysis of raw materials and final products. This study evaluates different analytical approaches in order to recognise the most suitable technique for the analysis of carbohydrates in herbal drug preparations. The specific focus of the study is on thin-layer chromatography (TLC), gas chromatography (GC), and a newly developed mass spectrometric method, i.e. matrix free material enhanced laser desorption/ionisation time of flight mass spectrometry (mf-MELDI-MS). Samples employed in the study were standards and microwave-assisted water extracts from Quercus. TLC analysis proved the presence of mono-, di- and trisaccharides within the biological sample and hinted at the existence of an unknown carbohydrate of higher oligomerisation degree. After evaluation of different derivatisation techniques, GC-MS confirmed data obtained via TLC for mono- to trisaccharides, delivering additionally quantified values under a considerable amount of time. A carbohydrate of higher oligomerisation degree could not be found. The application of mf-MELDI-MS further confirmed the presence of carbohydrates up to trisaccharides, also hinting at the presence of a form of tetrasaccharide. Besides this information, mf-MELDI-MS delivered further data about other substances present in the extract. Quantitative determination resulted in 1.750, 1.736 and 0.336 mg/mL for glucose, sucrose and raffinose respectively. Evaluation of all three techniques employed, clearly proved the heightened performance of mf-MELDI-MS for the qualitative analysis of complex mixtures, as targets do not need modification and analysis requires only a few minutes. In addition, GC-MS is suitable for quantitative analysis. Copyright © 2011 John Wiley & Sons, Ltd.

Use of COD, TOC, and Fluorescence Spectroscopy to Estimate BOD in Wastewater.

PubMed

Christian, Evelyn; Batista, Jacimaria R; Gerrity, Daniel

2017-02-01

  Common to all National Pollutant Discharge Elimination System (NPDES) permits in the United States is a limit on biochemical oxygen demand (BOD). Chemical oxygen demand (COD), total organic carbon (TOC), and fluorescence spectroscopy are also capable of quantifying organic content, although the mechanisms of quantification and the organic fractions targeted differ for each test. This study explores correlations between BOD5 and these alternate test procedures using facility influent, primary effluent, and facility effluent samples from a full-scale water resource recovery facility. Relative reductions of the water quality parameters proved to be strong indicators of their suitability as surrogates for BOD5. Suitable correlations were generally limited to the combined datasets for the three sampling locations or the facility effluent alone. COD exhibited relatively strong linear correlations with BOD5 when considering the three sample points (r = 0.985) and the facility effluent alone (r = 0.914), while TOC exhibited a suitable linear correlation with BOD5 in the facility effluent (r = 0.902). Exponential regressions proved to be useful for estimating BOD5 based on TOC or fluorescence (r > 0.95).

Determination of pesticides associated with suspended sediments in the San Joaquin River, California, USA, using gas chromatography-ion trap mass spectrometry

USGS Publications Warehouse

Bergamaschi, B.A.; Baston, D.S.; Crepeau, K.L.; Kuivila, K.M.

1999-01-01

An analytical method useful for the quantification of a range of pesticides and pesticide degradation products associated with suspended sediments was developed by testing a variety of extraction and cleanup schemes. The final extraction and cleanup methods chosen for use are suitable for the quantification of the listed pesticides using gas chromatography-ion trap mass spectrometry and the removal of interfering coextractable organic material found in suspended sediments. Methylene chloride extraction followed by Florisil cleanup proved most effective for separation of coextractives from the pesticide analytes. Removal of elemental sulfur was accomplished with tetrabutylammonium hydrogen sulfite. The suitability of the method for the analysis of a variety of pesticides was evaluated, and the method detection limits (MDLs) were determined (0.1-6.0 ng/g dry weight of sediment) for 21 compounds. Recovery of pesticides dried onto natural sediments averaged 63%. Analysis of duplicate San Joaquin River suspended-sediment samples demonstrated the utility of the method for environmental samples with variability between replicate analyses lower than between environmental samples. Eight of 21 pesticides measured were observed at concentrations ranging from the MDL to more than 80 ng/g dry weight of sediment and exhibited significant temporal variability. Sediment-associated pesticides, therefore, may contribute to the transport of pesticides through aquatic systems and should be studied separately from dissolved pesticides.

Comparative Validation of the Determination of Sofosbuvir in Pharmaceuticals by Several Inexpensive Ecofriendly Chromatographic, Electrophoretic, and Spectrophotometric Methods.

PubMed

El-Yazbi, Amira F

2017-07-01

Sofosbuvir (SOFO) was approved by the U.S. Food and Drug Administration in 2013 for the treatment of hepatitis C virus infection with enhanced antiviral potency compared with earlier analogs. Notwithstanding, all current editions of the pharmacopeias still do not present any analytical methods for the quantification of SOFO. Thus, rapid, simple, and ecofriendly methods for the routine analysis of commercial formulations of SOFO are desirable. In this study, five accurate methods for the determination of SOFO in pharmaceutical tablets were developed and validated. These methods include HPLC, capillary zone electrophoresis, HPTLC, and UV spectrophotometric and derivative spectrometry methods. The proposed methods proved to be rapid, simple, sensitive, selective, and accurate analytical procedures that were suitable for the reliable determination of SOFO in pharmaceutical tablets. An analysis of variance test with P-value > 0.05 confirmed that there were no significant differences between the proposed assays. Thus, any of these methods can be used for the routine analysis of SOFO in commercial tablets.

Pixel color feature enhancement for road signs detection

NASA Astrophysics Data System (ADS)

Zhang, Qieshi; Kamata, Sei-ichiro

2010-02-01

Road signs play an important role in our daily life which used to guide drivers to notice variety of road conditions and cautions. They provide important visual information that can help drivers operating their vehicles in a manner for enhancing traffic safety. The occurrence of some accidents can be reduced by using automatic road signs recognition system which can alert the drivers. This research attempts to develop a warning system to alert the drivers to notice the important road signs early enough to refrain road accidents from happening. For solving this, a non-linear weighted color enhancement method by pixels is presented. Due to the advantage of proposed method, different road signs can be detected from videos effectively. With suitably coefficients and operations, the experimental results have proved that the proposed method is robust, accurate and powerful in road signs detection.

A monolithic homotopy continuation algorithm with application to computational fluid dynamics

NASA Astrophysics Data System (ADS)

Brown, David A.; Zingg, David W.

2016-09-01

A new class of homotopy continuation methods is developed suitable for globalizing quasi-Newton methods for large sparse nonlinear systems of equations. The new continuation methods, described as monolithic homotopy continuation, differ from the classical predictor-corrector algorithm in that the predictor and corrector phases are replaced with a single phase which includes both a predictor and corrector component. Conditional convergence and stability are proved analytically. Using a Laplacian-like operator to construct the homotopy, the new algorithm is shown to be more efficient than the predictor-corrector homotopy continuation algorithm as well as an implementation of the widely-used pseudo-transient continuation algorithm for some inviscid and turbulent, subsonic and transonic external aerodynamic flows over the ONERA M6 wing and the NACA 0012 airfoil using a parallel implicit Newton-Krylov finite-difference flow solver.

A collection of edge-based elements

NASA Technical Reports Server (NTRS)

Kempel, Leo C.; Volakis, John L.

1992-01-01

Edge-based elements have proved useful in solving electromagnetic problems since they are nondivergent. Previous authors have presented several two and three dimensional elements. Herein, we present four types of elements which are suitable for modeling several types of three dimensional geometries. Distorted brick and triangular prism elements are given in cartesian coordinates as well as the specialized cylindrical shell and pie-shaped prism elements which are suitable for problems best described in polar cylindrical coordinates.

Quasivariational Solutions for First Order Quasilinear Equations with Gradient Constraint

NASA Astrophysics Data System (ADS)

Rodrigues, José Francisco; Santos, Lisa

2012-08-01

We prove the existence of solutions for a quasi-variational inequality of evolution with a first order quasilinear operator and a variable convex set which is characterized by a constraint on the absolute value of the gradient that depends on the solution itself. The only required assumption on the nonlinearity of this constraint is its continuity and positivity. The method relies on an appropriate parabolic regularization and suitable a priori estimates. We also obtain the existence of stationary solutions by studying the asymptotic behaviour in time. In the variational case, corresponding to a constraint independent of the solution, we also give uniqueness results.

Evaluation of Sparfloxacin Distribution by Mass Spectrometry Imaging in a Phototoxicity Model

NASA Astrophysics Data System (ADS)

Boudon, Stéphanie Marie; Morandi, Grégory; Prideaux, Brendan; Staab, Dieter; Junker, Ursula; Odermatt, Alex; Stoeckli, Markus; Bauer, Daniel

2014-10-01

Mass spectrometry imaging (MSI) was applied to samples from mouse skin and from a human in vitro 3D skin model in order to assess its suitability in the context of photosafety evaluation. MSI proved to be a suitable method for the detection of the model compound sparfloxacin in biological tissues following systemic administration (oral gavage, 100 mg/kg) and subsequent exposure to simulated sunlight. In the human in vitro 3D skin model, a concentration-dependent increase as well as an irradiation-dependent decrease of sparfloxacin was observed. The MSI data on samples from mouse skin showed high signals of sparfloxacin 8 h after dosing. In contrast, animals irradiated with simulated sunlight showed significantly lower signals for sparfloxacin starting already at 1 h postirradiation, with no measurable intensity at the later time points (3 h and 6 h), suggesting a time- and irradiation-dependent degradation of sparfloxacin. The acquisition resolution of 100 μm proved to be adequate for the visualization of the distribution of sparfloxacin in the gross ear tissue samples, but distinct skin compartments were unable to be resolved. The label-free detection of intact sparfloxacin was only the first step in an attempt to gain a deeper understanding of the phototoxic processes. Further work is needed to identify the degradation products of sparfloxacin implicated in the observed inflammatory processes in order to better understand the origin and the mechanism of the phototoxic reaction.

The structure of aqueous sodium hydroxide solutions: a combined solution x-ray diffraction and simulation study.

PubMed

Megyes, Tünde; Bálint, Szabolcs; Grósz, Tamás; Radnai, Tamás; Bakó, Imre; Sipos, Pál

2008-01-28

To determine the structure of aqueous sodium hydroxide solutions, results obtained from x-ray diffraction and computer simulation (molecular dynamics and Car-Parrinello) have been compared. The capabilities and limitations of the methods in describing the solution structure are discussed. For the solutions studied, diffraction methods were found to perform very well in describing the hydration spheres of the sodium ion and yield structural information on the anion's hydration structure. Classical molecular dynamics simulations were not able to correctly describe the bulk structure of these solutions. However, Car-Parrinello simulation proved to be a suitable tool in the detailed interpretation of the hydration sphere of ions and bulk structure of solutions. The results of Car-Parrinello simulations were compared with the findings of diffraction experiments.

Analysis of methods for growth detection in the search for extraterrestrial life.

PubMed

Merek, E L; Oyama, V I

1968-05-01

In the search for life on other planets, experiments designed to detect the growth of microorganisms may prove to be definitive when coupled with chemical characterization and metabolic experiments. If organisms are not abundant, growth provides the only means for obtaining a large mass of biological material suitable for chemical compositional analyses and metabolic assays. Several methods of monitoring growth are described. Of these, optical monitoring in a unique system free of soil particles is advanced as the most appropriate. Theoretical problems related to the formulation of culture media are discussed, and several possible solutions are proposed. The sampling system, the type of monitoring, the size and placement of inoculum, and the medium volume and composition are contingent upon one another and must be integrated without sacrifice to the biological demands.

The nucleolus is well-posed

NASA Astrophysics Data System (ADS)

Fragnelli, Vito; Patrone, Fioravante; Torre, Anna

2006-02-01

The lexicographic order is not representable by a real-valued function, contrary to many other orders or preorders. So, standard tools and results for well-posed minimum problems cannot be used. We prove that under suitable hypotheses it is however possible to guarantee the well-posedness of a lexicographic minimum over a compact or convex set. This result allows us to prove that some game theoretical solution concepts, based on lexicographic order are well-posed: in particular, this is true for the nucleolus.

Hiproofs

NASA Technical Reports Server (NTRS)

Denney, Ewen; Power, John

2003-01-01

We introduce a hierarchical notion of formal proof, useful in the implementation of theorem provers, which we call highproofs. Two alternative definitions are given, motivated by existing notations used in theorem proving research. We define transformations between these two forms of hiproof, develop notions of underlying proof, and give a suitable definition of refinement in order to model incremental proof development. We show that our transformations preserve both underlying proofs and refinement. The relationship of our theory to existing theorem proving systems is discussed, as is its future extension.

Bioremediation of contaminated surface water by immobilized Micrococcus roseus.

PubMed

Li, H; Li, P; Hua, T; Zhang, Y; Xiong, X; Gong, Z

2005-08-01

The problems caused by contaminated surface water have gradually become more serious in recent years. Although various remediation technologies were investigated, unfortunately, no efficient method was developed. In this paper, a new bioremediation technology was studied using Micrococcus roseus, which was immobilized in porous spherical beads by an improved polyvinyl alcohol (PVA) - sodium alginate (SA) embedding method. The experimental results indicated that COD removal rate could reach 64.7 % within 72 hours when immobilized M. roseus beads were used, which was ten times as high as that of free cells. The optimum inoculation rate of immobilized M. roseus beads was 10 % (mass percent of the beads in water sample, g g(-1)). Suitable aeration was proved necessary to enhance the bioremediation process. The immobilized cells had an excellent tolerance to pH and temperature changes, and were also more resistant to heavy metal stress compared with free cells. The immobilized M. roseus beads had an excellent regeneration capacity and could be reused after 180-day continuous usage. The Scanning Electronic Microscope (SEM) analysis showed that the bead microstructure was suitable for M. roseus growth, however, some defect structures should still be improved.

Recombinase polymerase and enzyme-linked immunosorbent assay as a DNA amplification-detection strategy for food analysis.

PubMed

Santiago-Felipe, S; Tortajada-Genaro, L A; Puchades, R; Maquieira, A

2014-02-06

Polymerase chain reaction in conjunction with enzyme-linked immunosorbent assay (PCR-ELISA) is a well-established technique that provides a suitable rapid, sensitive, and selective method for a broad range of applications. However, the need for precise rapid temperature cycling of PCR is an important drawback that can be overcome by employing isothermal amplification reactions such as recombinase polymerase amplification (RPA). The RPA-ELISA combination is proposed for amplification at a low, constant temperature (40°C) in a short time (40 min), for the hybridisation of labelled products to specific 5'-biotinylated probes/streptavidin in coated microtiter plates at room temperature, and for detection by colorimetric immunoassay. RPA-ELISA was applied to screen common safety threats in foodstuffs, such as allergens (hazelnut, peanut, soybean, tomato, and maize), genetically modified organisms (P35S and TNOS), pathogenic bacteria (Salmonella sp. and Cronobacter sp.), and fungi (Fusarium sp.). Satisfactory sensitivity and reproducibility results were achieved for all the targets. The RPA-ELISA technique does away with thermocycling and provides a suitable sensitive, specific, and cost-effective method for routine applications, and proves particularly useful for resource-limited settings. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of (GTG)5-PCR for identification of Enterococcus spp.

PubMed

Svec, Pavel; Vancanneyt, Marc; Seman, Milan; Snauwaert, Cindy; Lefebvre, Karen; Sedlácek, Ivo; Swings, Jean

2005-06-01

A set of reference strains and a group of previously unidentified enterococci were analysed by rep-PCR with the (GTG)(5) primer to evaluate the discriminatory power and suitability of this method for typing and identification of enterococcal species. A total of 49 strains representing all validly described species were obtained from bacterial collections. For more extensive evaluation of this identification approach 112 well-defined and identified enterococci isolated from bryndza cheese were tested. The (GTG)(5)-PCR fingerprinting assigned all strains into well-differentiated clusters representing individual species. Subsequently, a group including 44 unidentified enterococci isolated from surface waters was analysed to evaluate this method for identification of unknown isolates. Obtained band patterns allowed us to identify all the strains clearly to the species level. This study proved that rep-PCR with (GTG)(5) primer is a reliable and fast method for species identification of enterococci.

Overview of a workshop on screening methods for detecting potential (anti-) estrogenic/androgenic chemicals in wildlife

USGS Publications Warehouse

Ankley, Gerald T.; Mihaich, Ellen; Stahl, Ralph G.; Tillitt, Donald E.; Colborn, Theo; McMaster, Suzzanne; Miller, Ron; Bantle, John; Campbell, Pamela; Denslow, Nancy; Dickerson, Richard L.; Folmar, Leroy C.; Fry, Michael; Giesy, John P.; Gray, L. Earl; Guiney, Patrick; Hutchinson, Thomas; Kennedy, Sean W.; Kramer, Vincent; LeBlanc, Gerald A.; Mayes, Monte; Nimrod, Alison; Patino, Reynaldo; Peterson, Richard; Purdy, Richard; Ringer, Robert; Thomas, Peter C.; Touart, Les; Van Der Kraak, Glen; Zacharewski, Tim

1998-01-01

The U.S. Congress has passed legislation requiring the U.S. Environmental Protection Agency (U.S. EPA) to develop, validate, and implement screening tests for identifying potential endocrine-disrupting chemicals within 3 years. To aid in the identification of methods suitable for this purpose, the U.S. EPA, the Chemical Manufacturers Association, and the World Wildlife Fund sponsored several workshops, including the present one, which dealt with wildlife species. This workshop was convened with 30 international scientists representing multiple disciplines in March 1997 in Kansas City, Missouri, USA. Participants at the meeting identified methods in terms of their ability to indicate (anti-) estrogenic/androgenic effects, particularly in the context of developmental and reproductive processes. Data derived from structure-activity relationship models and in vitro test systems, although useful in certain contexts, cannot at present replace in vivo tests as the sole basis for screening. A consensus was reached that existing mammalian test methods (e.g., with rats or mice) generally are suitable as screens for assessing potential (anti-) estrogenic/ androgenic effects in mammalian wildlife. However, due to factors such as among-class variation in receptor structure and endocrine function, it is uncertain if these mammalian assays would be of broad utility as screens for other classes of vertebrate wildlife. Existing full and partial life-cycle tests with some avian and fish species could successfully identify chemicals causing endocrine disruption; however, these long-term tests are not suitable for routine screening. However, a number of short-term tests with species from these two classes exist that could serve as effective screening tools for chemicals inducing (anti-) estrogenic/androgenic effects. Existing methods suitable for identifying chemicals with these mechanisms of action in reptiles and amphibians are limited, but in the future, tests with species from these classes may prove highly effective as screens. In the case of invertebrate species, too little is known at present about the biological role of estrogens and androgens in reproduction and development to recommend specific assays.

Numerical Modelling of Foundation Slabs with use of Schur Complement Method

NASA Astrophysics Data System (ADS)

Koktan, Jiří; Brožovský, Jiří

2017-10-01

The paper discusses numerical modelling of foundation slabs with use of advanced numerical approaches, which are suitable for parallel processing. The solution is based on the Finite Element Method with the slab-type elements. The subsoil is modelled with use of Winklertype contact model (as an alternative a multi-parameter model can be used). The proposed modelling approach uses the Schur Complement method to speed-up the computations of the problem. The method is based on a special division of the analyzed model to several substructures. It adds some complexity to the numerical procedures, especially when subsoil models are used inside the finite element method solution. In other hand, this method makes possible a fast solution of large models but it introduces further problems to the process. Thus, the main aim of this paper is to verify that such method can be successfully used for this type of problem. The most suitable finite elements will be discussed, there will be also discussion related to finite element mesh and limitations of its construction for such problem. The core approaches of the implementation of the Schur Complement Method for this type of the problem will be also presented. The proposed approach was implemented in the form of a computer program, which will be also briefly introduced. There will be also presented results of example computations, which prove the speed-up of the solution - there will be shown important speed-up of solution even in the case of on-parallel processing and the ability of bypass size limitations of numerical models with use of the discussed approach.

Method for extracting relevant electrical parameters from graphene field-effect transistors using a physical model

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

Boscá, A., E-mail: alberto.bosca@upm.es; Dpto. de Ingeniería Electrónica, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, Madrid 28040; Pedrós, J.

2015-01-28

Due to its intrinsic high mobility, graphene has proved to be a suitable material for high-speed electronics, where graphene field-effect transistor (GFET) has shown excellent properties. In this work, we present a method for extracting relevant electrical parameters from GFET devices using a simple electrical characterization and a model fitting. With experimental data from the device output characteristics, the method allows to calculate parameters such as the mobility, the contact resistance, and the fixed charge. Differentiated electron and hole mobilities and direct connection with intrinsic material properties are some of the key aspects of this method. Moreover, the method outputmore » values can be correlated with several issues during key fabrication steps such as the graphene growth and transfer, the lithographic steps, or the metalization processes, providing a flexible tool for quality control in GFET fabrication, as well as a valuable feedback for improving the material-growth process.« less

On isocentre adjustment and quality control in linear accelerator based radiosurgery with circular collimators and room lasers.

PubMed

Treuer, H; Hoevels, M; Luyken, K; Gierich, A; Kocher, M; Müller, R P; Sturm, V

2000-08-01

We have developed a densitometric method for measuring the isocentric accuracy and the accuracy of marking the isocentre position for linear accelerator based radiosurgery with circular collimators and room lasers. Isocentric shots are used to determine the accuracy of marking the isocentre position with room lasers and star shots are used to determine the wobble of the gantry and table rotation movement, the effect of gantry sag, the stereotactic collimator alignment, and the minimal distance between gantry and table rotation axes. Since the method is based on densitometric measurements, beam spot stability is implicitly tested. The method developed is also suitable for quality assurance and has proved to be useful in optimizing isocentric accuracy. The method is simple to perform and only requires a film box and film scanner for instrumentation. Thus, the method has the potential to become widely available and may therefore be useful in standardizing the description of linear accelerator based radiosurgical systems.

A practical method for extending the biuret assay to protein determination of corn-based products.

PubMed

Liu, Zelong; Pan, Junhui

2017-06-01

A modified biuret method suitable for protein determination of corn-based products was developed by introducing a combination of an alkaline reagent with sodium dodecyl sulfate (reagent A) and heat treatments. The method was tested on seven corn-based samples. The results showed mostly good agreement (P>0.05) as compared to the Kjeldahl values. The proposed method was found to enhance the accuracy of prediction on zein content using bovine serum albumin as standard. Reagent A and sample treatment were proved to effectively improve protein solubilization for the thermally-dried corn-based products, e.g. corn gluten meal. The absorbance was stable for at least 1-h. Moreover, the whole measurement of protein content only needs 15-20min more than the traditional biuret assay, and can be performed in batches. The findings suggest that the proposed method could be a timesaving alternative for routine protein analyses in corn processing factories. Copyright © 2016 Elsevier Ltd. All rights reserved.

A self-sampling method to obtain large volumes of undiluted cervicovaginal secretions.

PubMed

Boskey, Elizabeth R; Moench, Thomas R; Hees, Paul S; Cone, Richard A

2003-02-01

Studies of vaginal physiology and pathophysiology sometime require larger volumes of undiluted cervicovaginal secretions than can be obtained by current methods. A convenient method for self-sampling these secretions outside a clinical setting can facilitate such studies of reproductive health. The goal was to develop a vaginal self-sampling method for collecting large volumes of undiluted cervicovaginal secretions. A menstrual collection device (the Instead cup) was inserted briefly into the vagina to collect secretions that were then retrieved from the cup by centrifugation in a 50-ml conical tube. All 16 women asked to perform this procedure found it feasible and acceptable. Among 27 samples, an average of 0.5 g of secretions (range, 0.1-1.5 g) was collected. This is a rapid and convenient self-sampling method for obtaining relatively large volumes of undiluted cervicovaginal secretions. It should prove suitable for a wide range of assays, including those involving sexually transmitted diseases, microbicides, vaginal physiology, immunology, and pathophysiology.

Sensitive life detection strategies for low-biomass environments: optimizing extraction of nucleic acids adsorbing to terrestrial and Mars analogue minerals.

PubMed

Direito, Susana O L; Marees, Andries; Röling, Wilfred F M

2012-07-01

The adsorption of nucleic acids to mineral matrixes can result in low extraction yields and negatively influences molecular microbial ecology studies, in particular for low-biomass environments on Earth and Mars. We determined the recovery of nucleic acids from a range of minerals relevant to Earth and Mars. Clay minerals, but also other silicates and nonsilicates, showed very low recovery (< 1%). Consequently, optimization of DNA extraction was directed towards clays. The high temperatures and acidic conditions used in some methods to dissolve mineral matrices proved to destruct DNA. The most efficient method comprised a high phosphate solution (P/EtOH; 1 M phosphate, 15% ethanol buffer at pH 8) introduced at the cell-lysing step in DNA extraction, to promote chemical competition with DNA for adsorption sites. This solution increased DNA yield from clay samples spiked with known quantities of cells up to nearly 100-fold. DNA recovery was also enhanced from several mineral samples retrieved from an aquifer, while maintaining reproducible DGGE profiles. DGGE profiles were obtained for a clay sample for which no profile could be generated with the standard DNA isolation protocol. Mineralogy influenced microbial community composition. The method also proved suitable for the recovery of low molecular weight DNA (< 1.5 kb). © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Diversity arrays technology (DArT) markers in apple for genetic linkage maps.

PubMed

Schouten, Henk J; van de Weg, W Eric; Carling, Jason; Khan, Sabaz Ali; McKay, Steven J; van Kaauwen, Martijn P W; Wittenberg, Alexander H J; Koehorst-van Putten, Herma J J; Noordijk, Yolanda; Gao, Zhongshan; Rees, D Jasper G; Van Dyk, Maria M; Jaccoud, Damian; Considine, Michael J; Kilian, Andrzej

2012-03-01

Diversity Arrays Technology (DArT) provides a high-throughput whole-genome genotyping platform for the detection and scoring of hundreds of polymorphic loci without any need for prior sequence information. The work presented here details the development and performance of a DArT genotyping array for apple. This is the first paper on DArT in horticultural trees. Genetic mapping of DArT markers in two mapping populations and their integration with other marker types showed that DArT is a powerful high-throughput method for obtaining accurate and reproducible marker data, despite the low cost per data point. This method appears to be suitable for aligning the genetic maps of different segregating populations. The standard complexity reduction method, based on the methylation-sensitive PstI restriction enzyme, resulted in a high frequency of markers, although there was 52-54% redundancy due to the repeated sampling of highly similar sequences. Sequencing of the marker clones showed that they are significantly enriched for low-copy, genic regions. The genome coverage using the standard method was 55-76%. For improved genome coverage, an alternative complexity reduction method was examined, which resulted in less redundancy and additional segregating markers. The DArT markers proved to be of high quality and were very suitable for genetic mapping at low cost for the apple, providing moderate genome coverage. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-011-9579-5) contains supplementary material, which is available to authorized users.

Recovery of Anisakid larvae by means of chloro-peptic digestion and proposal of the method for the official control.

PubMed

Fraulo, Pasquale; Morena, Carmelo; Costa, Antonella

2014-10-01

Anisakidae larvae belonging to the genera Anisakis and Pseudoterranova, are the most responsible for zoonosis transmitted by fish products (anisakidosis). Acquired by the consumption of raw or undercooked marine fish or squid, the anisakid larvae may cause pathogenic diseases like gastric or intestinal anisakiasis and gastro-allergic disorders. In accordance with current EU legislation, the fresh fish products must be inspected visually in order to detect the possible presence of visible parasites. It is recognized that the visual method is not accurate enough to detect the larvae of parasites in food preparations containing raw or practically raw seafood and it clearly emerges that the official system of control needs to be able to utilise an most efficient analytical technique. In this work, the authors have drawn up and validated an analytical method, which involves artificial digestion and the use of a heated magnetic stirrer, based on the EU Regulation n. 2075/2005. The larvae isolated are then subjected to morphological identification at genus level by using optical microscope. The method, proved to be suitable for the detection of live and dead larvae of anisakidae in ready-to-eat foodstuffs containing raw fish or cephalopods and it is fast and accurate. The method showed high levels of sensitivity and specificity, and the suitability of its use in official food control was confirmed. Its use should be incorporated systematically into specific monitoring programs for the control of foodstuffs containing raw fish products.

An automatic, closed-circuit oxygen consumption apparatus for small animals.

PubMed

Stock, M J

1975-11-01

An apparatus suitable for the continuous measurement of oxygen consumption of rats and mice is described. The system uses a motorized syringe dispenser to deliver fixed volumes of oxygen to a closed animal chamber. The dispenser is controlled by a micro-differential pressure switch to maintain chamber pressure slightly above ambient. The rate of oxygen consumption is determined by timing the interval between successive operations of the dispenser. The system has proved suitable for a range of experimental conditions and treatments.

Influence of process parameters on content uniformity of a low dose active pharmaceutical ingredient in a tablet formulation according to GMP.

PubMed

Muselík, Jan; Franc, Aleš; Doležel, Petr; Goněc, Roman; Krondlová, Anna; Lukášová, Ivana

2014-09-01

The article describes the development and production of tablets using direct compression of powder mixtures. The aim was to describe the impact of filler particle size and the time of lubricant addition during mixing on content uniformity according to the Good Manufacturing Practice (GMP) process validation requirements. Processes are regulated by complex directives, forcing the producers to validate, using sophisticated methods, the content uniformity of intermediates as well as final products. Cutting down of production time and material, shortening of analyses, and fast and reliable statistic evaluation of results can reduce the final price without affecting product quality. The manufacturing process of directly compressed tablets containing the low dose active pharmaceutical ingredient (API) warfarin, with content uniformity passing validation criteria, is used as a model example. Statistic methods have proved that the manufacturing process is reproducible. Methods suitable for elucidation of various properties of the final blend, e.g., measurement of electrostatic charge by Faraday pail and evaluation of mutual influences of researched variables by partial least square (PLS) regression, were used. Using these methods, it was proved that the filler with higher particle size increased the content uniformity of both blends and the ensuing tablets. Addition of the lubricant, magnesium stearate, during the blending process improved the content uniformity of blends containing the filler with larger particles. This seems to be caused by reduced sampling error due to the suppression of electrostatic charge.

Community structure from spectral properties in complex networks

NASA Astrophysics Data System (ADS)

Servedio, V. D. P.; Colaiori, F.; Capocci, A.; Caldarelli, G.

2005-06-01

We analyze the spectral properties of complex networks focusing on their relation to the community structure, and develop an algorithm based on correlations among components of different eigenvectors. The algorithm applies to general weighted networks, and, in a suitably modified version, to the case of directed networks. Our method allows to correctly detect communities in sharply partitioned graphs, however it is useful to the analysis of more complex networks, without a well defined cluster structure, as social and information networks. As an example, we test the algorithm on a large scale data-set from a psychological experiment of free word association, where it proves to be successful both in clustering words, and in uncovering mental association patterns.

SOME EXPERIMENTS ON THE TURBULENCE AND MUTUAL FRICTION IN LIQUID HELIUM (in French)

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

Kramers, H.C.

1962-05-01

Recent experiments on the hydrodynamic properties of liquid helium II, performed in the Kamerlingh Onnes Laboratorium (Leiden), are discussed on the basis of the twofluid model. Staas and Taconis measured temperature and pressure gradients occurring in a narrow circular capillary in the presence of a heat current. They discovered a turbulent phenomenon, very analogous to ordinary classical turbulence. The attenuation of second sound was studied by Wiarda and the present author in its dependence on a simultaneous continuous heat current. The method employed proves to be very suitable for a study of the so-called mutual friction and of phenomena occurringmore » in the critical velocity region. (auth)« less

Reasoning about Codata

NASA Astrophysics Data System (ADS)

Hinze, Ralf

Programmers happily use induction to prove properties of recursive programs. To show properties of corecursive programs they employ coinduction, but perhaps less enthusiastically. Coinduction is often considered a rather low-level proof method, in particular, as it departs quite radically from equational reasoning. Corecursive programs are conveniently defined using recursion equations. Suitably restricted, these equations possess unique solutions. Uniqueness gives rise to a simple and attractive proof technique, which essentially brings equational reasoning to the coworld. We illustrate the approach using two major examples: streams and infinite binary trees. Both coinductive types exhibit a rich structure: they are applicative functors or idioms, and they can be seen as memo-tables or tabulations. We show that definitions and calculations benefit immensely from this additional structure.

Study into the identification of irradiation ground paprika

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

Beczner, J.; Farkas, J.; Kiss, I.

From international colloquium: the identification of irradiated foodstuffs; Karlsruhe, Germany (24 Oct 1973). Several methods for the demonstration of irradiation in ground paprika were tested. In carbonyl compounds extracted by steam distillation unambiguous changes, which might have served as a basis for detecting irradiation, were not observed. Derivatography did not prove suitable either. On the basis of the size of ESR signal, the control sample and the irradiated one could be distinguished 2 to 3 weeks after irradiation. After a longer storage period, the size of the signal is irrelevant. Further study of the shape of the ESR signals maymore » yield valuable information in experiments on the demonstration of irradiation. (GE)« less

Stress assessment in small ruminants kept on city farms in southern Germany.

PubMed

Schilling, Anna-Katarina; Reese, Sven; Palme, Rupert; Erhard, Michael; Wöhr, Anna-Caroline

2015-01-01

Sheep and goats are frequently used in nonhuman animal-assisted activities on city farms. There are few data available on this type of usage of small ruminants. Health evaluations, behavioral observations (feeding, resting, comfort, explorative and social behaviors), behavioral tests (human approach tests and touch test), and measurements of fecal cortisol metabolites and heart rate were performed to assess stress levels in 25 sheep and 32 goats on 7 city farms and 2 activity playgrounds in Germany. No evidence was found that the animals suffered from major distress. Health evaluations, behavioral observations, and behavioral tests proved to be the methods of stress assessment most suitable for routine on-farm checks in these settings.

New convergence results for the scaled gradient projection method

NASA Astrophysics Data System (ADS)

Bonettini, S.; Prato, M.

2015-09-01

The aim of this paper is to deepen the convergence analysis of the scaled gradient projection (SGP) method, proposed by Bonettini et al in a recent paper for constrained smooth optimization. The main feature of SGP is the presence of a variable scaling matrix multiplying the gradient, which may change at each iteration. In the last few years, extensive numerical experimentation showed that SGP equipped with a suitable choice of the scaling matrix is a very effective tool for solving large scale variational problems arising in image and signal processing. In spite of the very reliable numerical results observed, only a weak convergence theorem is provided establishing that any limit point of the sequence generated by SGP is stationary. Here, under the only assumption that the objective function is convex and that a solution exists, we prove that the sequence generated by SGP converges to a minimum point, if the scaling matrices sequence satisfies a simple and implementable condition. Moreover, assuming that the gradient of the objective function is Lipschitz continuous, we are also able to prove the {O}(1/k) convergence rate with respect to the objective function values. Finally, we present the results of a numerical experience on some relevant image restoration problems, showing that the proposed scaling matrix selection rule performs well also from the computational point of view.

Comparative Validation of the Determination of Sofosbuvir in Pharmaceuticals by Several Inexpensive Ecofriendly Chromatographic, Electrophoretic, and Spectrophotometric Methods.

PubMed

El-Yazbi, Amira F

2017-01-20

Sofosbuvir (SOFO) was approved by the U.S. Food and Drug Administration in 2013 for the treatment of hepatitis C virusinfection with enhanced antiviral potency compared with earlier analogs. Notwithstanding, all current editions of the pharmacopeias still do not present any analytical methods for the quantification of SOFO. Thus, rapid, simple, and ecofriendly methods for the routine analysis of commercial formulations of SOFO are desirable. In this study, five accurate methods for the determination of SOFO in pharmaceutical tablets were developed and validated. These methods include HPLC, capillary zone electrophoresis, HPTLC, and UV spectrophotometric and derivative spectrometry methods. The proposed methods proved to be rapid, simple, sensitive, selective, and accurate analytical procedures that were suitable for the reliable determination of SOFO in pharmaceutical tablets. An analysis of variance test with <em>P</em>-value &#x003E; 0.05 confirmed that there were no significant differences between the proposed assays. Thus, any of these methods can be used for the routine analysis of SOFO in commercial tablets.

Physical cryptographic verification of nuclear warheads

PubMed Central

Kemp, R. Scott; Danagoulian, Areg; Macdonald, Ruaridh R.; Vavrek, Jayson R.

2016-01-01

How does one prove a claim about a highly sensitive object such as a nuclear weapon without revealing information about the object? This paradox has challenged nuclear arms control for more than five decades. We present a mechanism in the form of an interactive proof system that can validate the structure and composition of an object, such as a nuclear warhead, to arbitrary precision without revealing either its structure or composition. We introduce a tomographic method that simultaneously resolves both the geometric and isotopic makeup of an object. We also introduce a method of protecting information using a provably secure cryptographic hash that does not rely on electronics or software. These techniques, when combined with a suitable protocol, constitute an interactive proof system that could reject hoax items and clear authentic warheads with excellent sensitivity in reasonably short measurement times. PMID:27432959

Physical cryptographic verification of nuclear warheads

NASA Astrophysics Data System (ADS)

Kemp, R. Scott; Danagoulian, Areg; Macdonald, Ruaridh R.; Vavrek, Jayson R.

2016-08-01

How does one prove a claim about a highly sensitive object such as a nuclear weapon without revealing information about the object? This paradox has challenged nuclear arms control for more than five decades. We present a mechanism in the form of an interactive proof system that can validate the structure and composition of an object, such as a nuclear warhead, to arbitrary precision without revealing either its structure or composition. We introduce a tomographic method that simultaneously resolves both the geometric and isotopic makeup of an object. We also introduce a method of protecting information using a provably secure cryptographic hash that does not rely on electronics or software. These techniques, when combined with a suitable protocol, constitute an interactive proof system that could reject hoax items and clear authentic warheads with excellent sensitivity in reasonably short measurement times.

Physical cryptographic verification of nuclear warheads.

PubMed

Kemp, R Scott; Danagoulian, Areg; Macdonald, Ruaridh R; Vavrek, Jayson R

2016-08-02

How does one prove a claim about a highly sensitive object such as a nuclear weapon without revealing information about the object? This paradox has challenged nuclear arms control for more than five decades. We present a mechanism in the form of an interactive proof system that can validate the structure and composition of an object, such as a nuclear warhead, to arbitrary precision without revealing either its structure or composition. We introduce a tomographic method that simultaneously resolves both the geometric and isotopic makeup of an object. We also introduce a method of protecting information using a provably secure cryptographic hash that does not rely on electronics or software. These techniques, when combined with a suitable protocol, constitute an interactive proof system that could reject hoax items and clear authentic warheads with excellent sensitivity in reasonably short measurement times.

Image processing for identification and quantification of filamentous bacteria in in situ acquired images.

PubMed

Dias, Philipe A; Dunkel, Thiemo; Fajado, Diego A S; Gallegos, Erika de León; Denecke, Martin; Wiedemann, Philipp; Schneider, Fabio K; Suhr, Hajo

2016-06-11

In the activated sludge process, problems of filamentous bulking and foaming can occur due to overgrowth of certain filamentous bacteria. Nowadays, these microorganisms are typically monitored by means of light microscopy, commonly combined with staining techniques. As drawbacks, these methods are susceptible to human errors, subjectivity and limited by the use of discontinuous microscopy. The in situ microscope appears as a suitable tool for continuous monitoring of filamentous bacteria, providing real-time examination, automated analysis and eliminating sampling, preparation and transport of samples. In this context, a proper image processing algorithm is proposed for automated recognition and measurement of filamentous objects. This work introduces a method for real-time evaluation of images without any staining, phase-contrast or dilution techniques, differently from studies present in the literature. Moreover, we introduce an algorithm which estimates the total extended filament length based on geodesic distance calculation. For a period of twelve months, samples from an industrial activated sludge plant were weekly collected and imaged without any prior conditioning, replicating real environment conditions. Trends of filament growth rate-the most important parameter for decision making-are correctly identified. For reference images whose filaments were marked by specialists, the algorithm correctly recognized 72 % of the filaments pixels, with a false positive rate of at most 14 %. An average execution time of 0.7 s per image was achieved. Experiments have shown that the designed algorithm provided a suitable quantification of filaments when compared with human perception and standard methods. The algorithm's average execution time proved its suitability for being optimally mapped into a computational architecture to provide real-time monitoring.

Automatic localization of cerebral cortical malformations using fractal analysis.

PubMed

De Luca, A; Arrigoni, F; Romaniello, R; Triulzi, F M; Peruzzo, D; Bertoldo, A

2016-08-21

Malformations of cortical development (MCDs) encompass a variety of brain disorders affecting the normal development and organization of the brain cortex. The relatively low incidence and the extreme heterogeneity of these disorders hamper the application of classical group level approaches for the detection of lesions. Here, we present a geometrical descriptor for a voxel level analysis based on fractal geometry, then define two similarity measures to detect the lesions at single subject level. The pipeline was applied to 15 normal children and nine pediatric patients affected by MCDs following two criteria, maximum accuracy (WACC) and minimization of false positives (FPR), and proved that our lesion detection algorithm is able to detect and locate abnormalities of the brain cortex with high specificity (WACC  =  85%, FPR  =  96%), sensitivity (WACC  =  83%, FPR  =  63%) and accuracy (WACC  =  85%, FPR  =  90%). The combination of global and local features proves to be effective, making the algorithm suitable for the detection of both focal and diffused malformations. Compared to other existing algorithms, this method shows higher accuracy and sensitivity.

Automatic localization of cerebral cortical malformations using fractal analysis

NASA Astrophysics Data System (ADS)

De Luca, A.; Arrigoni, F.; Romaniello, R.; Triulzi, F. M.; Peruzzo, D.; Bertoldo, A.

2016-08-01

Malformations of cortical development (MCDs) encompass a variety of brain disorders affecting the normal development and organization of the brain cortex. The relatively low incidence and the extreme heterogeneity of these disorders hamper the application of classical group level approaches for the detection of lesions. Here, we present a geometrical descriptor for a voxel level analysis based on fractal geometry, then define two similarity measures to detect the lesions at single subject level. The pipeline was applied to 15 normal children and nine pediatric patients affected by MCDs following two criteria, maximum accuracy (WACC) and minimization of false positives (FPR), and proved that our lesion detection algorithm is able to detect and locate abnormalities of the brain cortex with high specificity (WACC  =  85%, FPR  =  96%), sensitivity (WACC  =  83%, FPR  =  63%) and accuracy (WACC  =  85%, FPR  =  90%). The combination of global and local features proves to be effective, making the algorithm suitable for the detection of both focal and diffused malformations. Compared to other existing algorithms, this method shows higher accuracy and sensitivity.

Evaluation of direct and indirect ethanol biomarkers using a likelihood ratio approach to identify chronic alcohol abusers for forensic purposes.

PubMed

Alladio, Eugenio; Martyna, Agnieszka; Salomone, Alberto; Pirro, Valentina; Vincenti, Marco; Zadora, Grzegorz

2017-02-01

The detection of direct ethanol metabolites, such as ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs), in scalp hair is considered the optimal strategy to effectively recognize chronic alcohol misuses by means of specific cut-offs suggested by the Society of Hair Testing. However, several factors (e.g. hair treatments) may alter the correlation between alcohol intake and biomarkers concentrations, possibly introducing bias in the interpretative process and conclusions. 125 subjects with various drinking habits were subjected to blood and hair sampling to determine indirect (e.g. CDT) and direct alcohol biomarkers. The overall data were investigated using several multivariate statistical methods. A likelihood ratio (LR) approach was used for the first time to provide predictive models for the diagnosis of alcohol abuse, based on different combinations of direct and indirect alcohol biomarkers. LR strategies provide a more robust outcome than the plain comparison with cut-off values, where tiny changes in the analytical results can lead to dramatic divergence in the way they are interpreted. An LR model combining EtG and FAEEs hair concentrations proved to discriminate non-chronic from chronic consumers with ideal correct classification rates, whereas the contribution of indirect biomarkers proved to be negligible. Optimal results were observed using a novel approach that associates LR methods with multivariate statistics. In particular, the combination of LR approach with either Principal Component Analysis (PCA) or Linear Discriminant Analysis (LDA) proved successful in discriminating chronic from non-chronic alcohol drinkers. These LR models were subsequently tested on an independent dataset of 43 individuals, which confirmed their high efficiency. These models proved to be less prone to bias than EtG and FAEEs independently considered. In conclusion, LR models may represent an efficient strategy to sustain the diagnosis of chronic alcohol consumption and provide a suitable gradation to support the judgment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Detection of Legionella pneumophila by PCR-ELISA method in industrial cooling tower water.

PubMed

Soheili, Majid; Nejadmoghaddam, Mohammad Reza; Babashamsi, Mohammad; Ghasemi, Jamileh; Jeddi Tehrani, Mahmood

2007-11-15

Water supply and Cooling Tower Water (CTW) are among the most common sources of Legionella pneumophila (LP) contamination. A nonradio active method is described to detect LP in industrial CTW samples. DNA was purified and amplified by nested -PCR with amplimers specific for the 16s rRNA gene of LP. The 5' end biotinylated oligomer probe was immobilized on sterptavidin B coated microtiter plates. The nested-PCR product was labeled with digoxigenin and then hybridized with 5'-biotinylated probes. The amplification products were detected by using proxidase-labled anti dioxygenin antibody in a colorimetric reaction. The assay detected LP present in 1 L of 5 CTW samples examined. All of the samples were Legionella positive in both culture and PCR-ELISA methods. The PCR-ELISA assay appears to exhibit high specificity and is a more rapid technique in comparison with bacterial culture method. Thus could prove suitable for use in the routine examination of industrial CTW contamination.

New Logic Circuit with DC Parametric Excitation

NASA Astrophysics Data System (ADS)

Sugahara, Masanori; Kaneda, Hisayoshi

1982-12-01

It is shown that dc parametric excitation is possible in a circuit named JUDO, which is composed of two resistively-connected Josephson junctions. Simulation study proves that the circuit has large gain and properties suitable for the construction of small, high-speed logic circuits.

Uncertainty relations with quantum memory for the Wehrl entropy

NASA Astrophysics Data System (ADS)

De Palma, Giacomo

2018-03-01

We prove two new fundamental uncertainty relations with quantum memory for the Wehrl entropy. The first relation applies to the bipartite memory scenario. It determines the minimum conditional Wehrl entropy among all the quantum states with a given conditional von Neumann entropy and proves that this minimum is asymptotically achieved by a suitable sequence of quantum Gaussian states. The second relation applies to the tripartite memory scenario. It determines the minimum of the sum of the Wehrl entropy of a quantum state conditioned on the first memory quantum system with the Wehrl entropy of the same state conditioned on the second memory quantum system and proves that also this minimum is asymptotically achieved by a suitable sequence of quantum Gaussian states. The Wehrl entropy of a quantum state is the Shannon differential entropy of the outcome of a heterodyne measurement performed on the state. The heterodyne measurement is one of the main measurements in quantum optics and lies at the basis of one of the most promising protocols for quantum key distribution. These fundamental entropic uncertainty relations will be a valuable tool in quantum information and will, for example, find application in security proofs of quantum key distribution protocols in the asymptotic regime and in entanglement witnessing in quantum optics.

Comparative analysis of minimal residual disease detection using four-color flow cytometry, consensus IgH-PCR, and quantitative IgH PCR in CLL after allogeneic and autologous stem cell transplantation.

PubMed

Böttcher, S; Ritgen, M; Pott, C; Brüggemann, M; Raff, T; Stilgenbauer, S; Döhner, H; Dreger, P; Kneba, M

2004-10-01

The clinically most suitable method for minimal residual disease (MRD) detection in chronic lymphocytic leukemia is still controversial. We prospectively compared MRD assessment in 158 blood samples of 74 patients with CLL after stem cell transplantation (SCT) using four-color flow cytometry (MRD flow) in parallel with consensus IgH-PCR and ASO IgH real-time PCR (ASO IgH RQ-PCR). In 25 out of 106 samples (23.6%) with a polyclonal consensus IgH-PCR pattern, MRD flow still detected CLL cells, proving higher sensitivity of flow cytometry over PCR-genescanning with consensus IgH-primers. Of 92 samples, 14 (15.2%) analyzed in parallel by MRD flow and by ASO IgH RQ-PCR were negative by our flow cytometric assay but positive by PCR, thus demonstrating superior sensitivity of RQ-PCR with ASO primers. Quantitative MRD levels measured by both methods correlated well (r=0.93). MRD detection by flow and ASO IgH RQ-PCR were equally suitable to monitor MRD kinetics after allogeneic SCT, but the PCR method detected impending relapses after autologous SCT earlier. An analysis of factors that influence sensitivity and specificity of flow cytometry for MRD detection allowed to devise further improvements of this technique.

Supervision of Ethylene Propylene Diene M-Class (EPDM) Rubber Vulcanization and Recovery Processes Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy and Multivariate Analysis.

PubMed

Riba Ruiz, Jordi-Roger; Canals, Trini; Cantero, Rosa

2017-01-01

Ethylene propylene diene monomer (EPDM) rubber is widely used in a diverse type of applications, such as the automotive, industrial and construction sectors among others. Due to its appealing features, the consumption of vulcanized EPDM rubber is growing significantly. However, environmental issues are forcing the application of devulcanization processes to facilitate recovery, which has led rubber manufacturers to implement strict quality controls. Consequently, it is important to develop methods for supervising the vulcanizing and recovery processes of such products. This paper deals with the supervision process of EPDM compounds by means of Fourier transform mid-infrared (FT-IR) spectroscopy and suitable multivariate statistical methods. An expedited and nondestructive classification approach was applied to a sufficient number of EPDM samples with different applied processes, that is, with and without application of vulcanizing agents, vulcanized samples, and microwave treated samples. First the FT-IR spectra of the samples is acquired and next it is processed by applying suitable feature extraction methods, i.e., principal component analysis and canonical variate analysis to obtain the latent variables to be used for classifying test EPDM samples. Finally, the k nearest neighbor algorithm was used in the classification stage. Experimental results prove the accuracy of the proposed method and the potential of FT-IR spectroscopy in this area, since the classification accuracy can be as high as 100%.

Breast Cancer Diagnosis Using a Microfluidic Multiplexed Immunohistochemistry Platform

PubMed Central

Kim, Minseok S.; Kim, Taemin; Kong, Sun-Young; Kwon, Soim; Bae, Chae Yun; Choi, Jaekyu; Kim, Chul Hwan; Lee, Eun Sook; Park, Je-Kyun

2010-01-01

Background Biomarkers play a key role in risk assessment, assessing treatment response, and detecting recurrence and the investigation of multiple biomarkers may also prove useful in accurate prediction and prognosis of cancers. Immunohistochemistry (IHC) has been a major diagnostic tool to identify therapeutic biomarkers and to subclassify breast cancer patients. However, there is no suitable IHC platform for multiplex assay toward personalized cancer therapy. Here, we report a microfluidics-based multiplexed IHC (MMIHC) platform that significantly improves IHC performance in reduction of time and tissue consumption, quantification, consistency, sensitivity, specificity and cost-effectiveness. Methodology/Principal Findings By creating a simple and robust interface between the device and human breast tissue samples, we not only applied conventional thin-section tissues into on-chip without any additional modification process, but also attained perfect fluid control for various solutions, without any leakage, bubble formation, or cross-contamination. Four biomarkers, estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2), progesterone receptor (PR) and Ki-67, were examined simultaneously on breast cancer cells and human breast cancer tissues. The MMIHC method improved immunoreaction, reducing time and reagent consumption. Moreover, it showed the availability of semi-quantitative analysis by comparing Western blot. Concordance study proved strong consensus between conventional whole-section analysis and MMIHC (n = 105, lowest Kendall's coefficient of concordance, 0.90). To demonstrate the suitability of MMIHC for scarce samples, it was also applied successfully to tissues from needle biopsies. Conclusions/Significance The microfluidic system, for the first time, was successfully applied to human clinical tissue samples and histopathological diagnosis was realized for breast cancers. Our results showing substantial agreement indicate that several cancer-related proteins can be simultaneously investigated on a single tumor section, giving clear advantages and technical advances over standard immunohistochemical method. This novel concept will enable histopathological diagnosis using numerous specific biomarkers at a time even for small-sized specimens, thus facilitating the individualization of cancer therapy. PMID:20454672

Polyurethane Filler for Electroplating

NASA Technical Reports Server (NTRS)

Beasley, J. L.

1984-01-01

Polyurethane foam proves suitable as filler for slots in parts electroplated with copper or nickel. Polyurethane causes less contamination of plating bath and of cleaning and filtering tanks than wax fillers used previously. Direct cost of maintenance and indirect cost of reduced operating time during tank cleaning also reduced.

In situ analysis and structural elucidation of sainfoin (Onobrychis viciifolia) tannins for high-throughput germplasm screening.

PubMed

Gea, An; Stringano, Elisabetta; Brown, Ron H; Mueller-Harvey, Irene

2011-01-26

A rapid thiolytic degradation and cleanup procedure was developed for analyzing tannins directly in chlorophyll-containing sainfoin ( Onobrychis viciifolia ) plants. The technique proved suitable for complex tannin mixtures containing catechin, epicatechin, gallocatechin, and epigallocatechin flavan-3-ol units. The reaction time was standardized at 60 min to minimize the loss of structural information as a result of epimerization and degradation of terminal flavan-3-ol units. The results were evaluated by separate analysis of extractable and unextractable tannins, which accounted for 63.6-113.7% of the in situ plant tannins. It is of note that 70% aqueous acetone extracted tannins with a lower mean degree of polymerization (mDP) than was found for tannins analyzed in situ. Extractable tannins had between 4 and 29 lower mDP values. The method was validated by comparing results from individual and mixed sample sets. The tannin composition of different sainfoin accessions covered a range of mDP values from 16 to 83, procyanidin/prodelphinidin (PC/PD) ratios from 19.2/80.8 to 45.6/54.4, and cis/trans ratios from 74.1/25.9 to 88.0/12.0. This is the first high-throughput screening method that is suitable for analyzing condensed tannin contents and structural composition directly in green plant tissue.

Age estimation based on aspartic acid racemization in human sclera.

PubMed

Klumb, Karolin; Matzenauer, Christian; Reckert, Alexandra; Lehmann, Klaus; Ritz-Timme, Stefanie

2016-01-01

Age estimation based on racemization of aspartic acid residues (AAR) in permanent proteins has been established in forensic medicine for years. While dentine is the tissue of choice for this molecular method of age estimation, teeth are not always available which leads to the need to identify other suitable tissues. We examined the suitability of total tissue samples of human sclera for the estimation of age at death. Sixty-five samples of scleral tissue were analyzed. The samples were hydrolyzed and after derivatization, the extent of aspartic acid racemization was determined by gas chromatography. The degree of AAR increased with age. In samples from younger individuals, the correlation of age and D-aspartic acid content was closer than in samples from older individuals. The age-dependent racemization in total tissue samples proves that permanent or at least long-living proteins are present in scleral tissue. The correlation of AAR in human sclera and age at death is close enough to serve as basis for age estimation. However, the precision of age estimation by this method is lower than that of age estimation based on the analysis of dentine which is due to molecular inhomogeneities of total tissue samples of sclera. Nevertheless, the approach may serve as a valuable alternative or addition in exceptional cases.

Research Objectives for Human Missions in the Proving Ground of Cis-Lunar Space

NASA Technical Reports Server (NTRS)

Niles, P. B.; Eppler, D. B.; Kennedy, K. J.; Lewis, R.; Spann, J. F.; Sullivan, T. A.

2016-01-01

Beginning in as early as 2023, crewed missions beyond low Earth orbit will begin enabled by the new capabilities of the SLS and Orion vehicles. This will initiate the "Proving Ground" phase of human exploration with Mars as an ultimate destination. The primary goal of the Proving Ground is to demonstrate the capability of suitably long duration spaceflight without need of continuous support from Earth, i.e. become Earth Independent. A major component of the Proving Ground phase is to conduct research activities aimed at accomplishing major objectives selected from a wide variety of disciplines including but not limited to: Astronomy, Heliophysics, Fundamental Physics, Planetary Science, Earth Science, Human Systems, Fundamental Space Biology, Microgravity, and In A major component of the Proving Ground phase is to conduct research activities aimed at accomplishing major objectives selected from a wide variety of disciplines including but not limited to: Astronomy, Heliophysics, Fundamental Physics, Planetary Science, Earth Science, Human Systems, Fundamental Space Biology, Microgravity, and In Situ Resource Utilization. Mapping and prioritizing the most important objectives from these disciplines will provide a strong foundation for establishing the architecture to be utilized in the Proving Ground.

A validated stability-indicating UPLC method for desloratadine and its impurities in pharmaceutical dosage forms.

PubMed

Rao, Dantu Durga; Satyanarayana, N V; Malleswara Reddy, A; Sait, Shakil S; Chakole, Dinesh; Mukkanti, K

2010-02-05

A novel stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the determination of purity of desloratadine in presence of its impurities and forced degradation products. The method was developed using Waters Aquity BEH C18 column with mobile phase containing a gradient mixture of solvents A and B. The eluted compounds were monitored at 280nm. The run time was 8min within which desloratadine and its five impurities were well separated. Desloratadine was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Desloratadine was found to degrade significantly in oxidative and thermal stress conditions and stable in acid, base, hydrolytic and photolytic degradation conditions. The degradation products were well resolved from main peak and its impurities, thus proved the stability-indicating power of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of desloratadine in pharmaceutical dosage forms.

An analysis of the suitability of a low-cost eye tracker for assessing the cognitive load of drivers.

PubMed

Čegovnik, Tomaž; Stojmenova, Kristina; Jakus, Grega; Sodnik, Jaka

2018-04-01

This paper presents a driving simulator study in which we investigated whether the Eye Tribe eye tracker (ET) is capable of assessing changes in the cognitive load of drivers through oculography and pupillometry. In the study, participants were asked to drive a simulated vehicle and simultaneously perform a set of secondary tasks with different cognitive complexity levels. We measured changes in eye properties, such as the pupil size, blink rate and fixation time. We also performed a measurement with a Detection Response Task (DRT) to validate the results and to prove a steady increase of cognitive load with increasing secondary task difficulty. The results showed that the ET precisely recognizes an increasing pupil diameter with increasing secondary task difficulty. In addition, the ET shows increasing blink rates, decreasing fixation time and narrowing of the attention field with increasing secondary task difficulty. The results were validated with the DRT method and the secondary task performance. We conclude that the Eye Tribe ET is a suitable device for assessing a driver's cognitive load. Copyright © 2017 Elsevier Ltd. All rights reserved.

Factor analysis in optimization of formulation of high content uniformity tablets containing low dose active substance.

PubMed

Lukášová, Ivana; Muselík, Jan; Franc, Aleš; Goněc, Roman; Mika, Filip; Vetchý, David

2017-11-15

Warfarin is intensively discussed drug with narrow therapeutic range. There have been cases of bleeding attributed to varying content or altered quality of the active substance. Factor analysis is useful for finding suitable technological parameters leading to high content uniformity of tablets containing low amount of active substance. The composition of tabletting blend and technological procedure were set with respect to factor analysis of previously published results. The correctness of set parameters was checked by manufacturing and evaluation of tablets containing 1-10mg of warfarin sodium. The robustness of suggested technology was checked by using "worst case scenario" and statistical evaluation of European Pharmacopoeia (EP) content uniformity limits with respect to Bergum division and process capability index (Cpk). To evaluate the quality of active substance and tablets, dissolution method was developed (water; EP apparatus II; 25rpm), allowing for statistical comparison of dissolution profiles. Obtained results prove the suitability of factor analysis to optimize the composition with respect to batches manufactured previously and thus the use of metaanalysis under industrial conditions is feasible. Copyright © 2017 Elsevier B.V. All rights reserved.

4-Hydroxyanisole: the most suitable monophenolic substrate for determining spectrophotometrically the monophenolase activity of polyphenol oxidase from fruits and vegetables.

PubMed

Espín, J C; Tudela, J; García-Cánovas, F

1998-05-15

A continuous spectrophotometric method for determining the monophenolase activity of polyphenol oxidase from several plant sources is described. This assay method is based on the coupling reaction between 3-methyl-2-benzothiazolinone hydrazone and the quinone product of the oxidation of 4-hydroxyanisole in the presence of polyphenol oxidase. 4-Hydroxyanisole proved to be the best monophenol assayed to measure the monophenolase activity of polyphenol oxidase from apple, artichoke, avocado, medlar, pear, and strawberry. Kinetic constants of 4-hydroxyanisole were compared to those of p-hydroxyphenyl propionic acid, a very sensitive monophenol previously reported to assay the monophenolase activity of polyphenol oxidase from apple, pear, and mushroom. The high values of the maximum steady state rate obtained for 4-hydroxyanisole suggest the existence of high catalytic constant toward this monophenol. These kinetic values were supported by nuclear magnetic resonance assays which predicted the highest reactivity of 4-hydroxyanisole. Therefore nuclear magnetic resonance assays proved to be a valuable and useful tool to predict the best monophenolic substrate for plant polyphenol oxidases. The 3-methyl-2-benzothiazlolinone-adduct for 4-hydroxyanisole was stable, with high molar absorptivity at the optimum pHs of the polyphenol oxidases assayed. All this together makes the use of 4-hydroxyanisol as monophenolic substrate and 3-methyl-2-benzothiazolinone as coupling reagent the most sensitive and precise assay method up to date reported in the literature to determine the monophenolas activity of polyphenol oxidase from fruits and vegetables.

[Binding properties of components removable from dental base plate, analysed by Fourier-Transform Surface Plasmon Resonance (FT-SPR) method].

PubMed

Bakó, József; Kelemen, Máté; Szalóki, Melinda; Vitályos, Géza; Radics, Tünde; Hegedüs, Csaba

2015-03-01

In parallel with the emergence of new dental materials the number of allergic diseases is continuously increasing. Extremely small quantities of the allergens are capable to inducing an allergic reaction. Therefore it is particularly important to examine these materials as antigens and investigate their binding properties to proteins (e.g. formaldehyde, methacrylic acid, benzoyl-peroxide...). The Fourier Transform Surface Plasmon Resonance Spectroscopy (FT-SPR) is a suitable examination method for this type of procedure. FT-SPR measurement is performed at a fixed angel of incident light, and reflectivity is measured over a range of wavelength in the near infrared. The advantages of this method are the outstanding sensitivity, the label-free detection capability and the possibility of the real-time testing procedure. Formaldehyde and methacrylic acid are among the most common dental allergens. In our study we examined these molecules by FT-SPR spectroscopy. The aim of this work was to investigate the suitability of this method to the detection of these materials, with special focuses on the analysis and evaluation concentration-dependent measurements. Different concentrations (0.01 %-0.2%) of formaldehyde and methacrylic acid solutions were measured. The individual spectra were measured for all of the solutions, and calibration curves were calculated for the materials for the possibility of the determination of an unknown concentration. The results confirmed that the method is theoretically capable to detect hundred-thousandths scale concentration-changes in the solution flowing above the SPR-chip. The concentration-dependent studies had proved that the method capable to measure directly these materials and can provide appropriate calibration for quantitative determination. These experiments show the broad applicability of the FT-SPR method, which can greatly facilitate the mapping and understanding of biomolecular interactions in the future.

Comparison between hybrid laser-MIG welding and MIG welding for the invar36 alloy

NASA Astrophysics Data System (ADS)

Zhan, Xiaohong; Li, Yubo; Ou, Wenmin; Yu, Fengyi; Chen, Jie; Wei, Yanhong

2016-11-01

The invar36 alloy is suitable to produce mold of composite materials structure because it has similar thermal expansion coefficient with composite materials. In the present paper, the MIG welding and laser-MIG hybrid welding methods are compared to get the more appropriate method to overcome the poor weldability of invar36 alloy. According to the analysis of the experimental and simulated results, it has been proved that the Gauss and cone combined heat source model can characterize the laser-MIG hybrid welding heat source well. The total welding time of MIG welding is 8 times that of hybrid laser-MIG welding. The welding material consumption of MIG welding is about 4 times that of hybrid laser-MIG welding. The stress and deformation simulation indicate that the peak value of deformation during MIG welding is 3 times larger than that of hybrid laser-MIG welding.

Sample Training Based Wildfire Segmentation by 2D Histogram θ-Division with Minimum Error

PubMed Central

Dong, Erqian; Sun, Mingui; Jia, Wenyan; Zhang, Dengyi; Yuan, Zhiyong

2013-01-01

A novel wildfire segmentation algorithm is proposed with the help of sample training based 2D histogram θ-division and minimum error. Based on minimum error principle and 2D color histogram, the θ-division methods were presented recently, but application of prior knowledge on them has not been explored. For the specific problem of wildfire segmentation, we collect sample images with manually labeled fire pixels. Then we define the probability function of error division to evaluate θ-division segmentations, and the optimal angle θ is determined by sample training. Performances in different color channels are compared, and the suitable channel is selected. To further improve the accuracy, the combination approach is presented with both θ-division and other segmentation methods such as GMM. Our approach is tested on real images, and the experiments prove its efficiency for wildfire segmentation. PMID:23878526

Performance comparison of heuristic algorithms for task scheduling in IaaS cloud computing environment.

PubMed

Madni, Syed Hamid Hussain; Abd Latiff, Muhammad Shafie; Abdullahi, Mohammed; Abdulhamid, Shafi'i Muhammad; Usman, Mohammed Joda

2017-01-01

Cloud computing infrastructure is suitable for meeting computational needs of large task sizes. Optimal scheduling of tasks in cloud computing environment has been proved to be an NP-complete problem, hence the need for the application of heuristic methods. Several heuristic algorithms have been developed and used in addressing this problem, but choosing the appropriate algorithm for solving task assignment problem of a particular nature is difficult since the methods are developed under different assumptions. Therefore, six rule based heuristic algorithms are implemented and used to schedule autonomous tasks in homogeneous and heterogeneous environments with the aim of comparing their performance in terms of cost, degree of imbalance, makespan and throughput. First Come First Serve (FCFS), Minimum Completion Time (MCT), Minimum Execution Time (MET), Max-min, Min-min and Sufferage are the heuristic algorithms considered for the performance comparison and analysis of task scheduling in cloud computing.

Performance comparison of heuristic algorithms for task scheduling in IaaS cloud computing environment

PubMed Central

Madni, Syed Hamid Hussain; Abd Latiff, Muhammad Shafie; Abdullahi, Mohammed; Usman, Mohammed Joda

2017-01-01

Cloud computing infrastructure is suitable for meeting computational needs of large task sizes. Optimal scheduling of tasks in cloud computing environment has been proved to be an NP-complete problem, hence the need for the application of heuristic methods. Several heuristic algorithms have been developed and used in addressing this problem, but choosing the appropriate algorithm for solving task assignment problem of a particular nature is difficult since the methods are developed under different assumptions. Therefore, six rule based heuristic algorithms are implemented and used to schedule autonomous tasks in homogeneous and heterogeneous environments with the aim of comparing their performance in terms of cost, degree of imbalance, makespan and throughput. First Come First Serve (FCFS), Minimum Completion Time (MCT), Minimum Execution Time (MET), Max-min, Min-min and Sufferage are the heuristic algorithms considered for the performance comparison and analysis of task scheduling in cloud computing. PMID:28467505

Laser Beam Welding of Ultra-high Strength Chromium Steel with Martensitic Microstructure

NASA Astrophysics Data System (ADS)

Dahmen, Martin; Janzen, Vitalij; Lindner, Stefan; Wagener, Rainer

A new class of steels is going to be introduced into sheet manufacturing. Stainless ferritic and martensitic steels open up opportunities for sheet metal fabrication including hot stamping. Strengths of up to 2 GPa at fracture elongations of 15% can be attained through this. Welding of these materials, as a result, became a challenge. Energy-reduced welding methods with in-situ heat treatment are required in order to ensure the delicate and complex heat control. Laser beam welding is the joining technique of choice to supply minimum heat input to the fusion process and to apply efficient heat control. For two application cases, tailored blank production in as-rolled condition and welding during assembly in hot stamped condition, welding processes have been developed. The welding suitability is shown through metallurgical investigations of the welds. Crash tests based on the KS-II concept as well as fatigue tests prove the applicability of the joining method.

Detection of compatibility between baclofen and excipients with aid of infrared spectroscopy and chemometry

NASA Astrophysics Data System (ADS)

Rojek, Barbara; Wesolowski, Marek; Suchacz, Bogdan

2013-12-01

In the paper infrared (IR) spectroscopy and multivariate exploration techniques: principal component analysis (PCA) and cluster analysis (CA) were applied as supportive methods for the detection of physicochemical incompatibilities between baclofen and excipients. In the course of research, the most useful rotational strategy in PCA proved to be varimax normalized, while in CA Ward's hierarchical agglomeration with Euclidean distance measure enabled to yield the most interpretable results. Chemometrical calculations confirmed the suitability of PCA and CA as the auxiliary methods for interpretation of infrared spectra in order to recognize whether compatibilities or incompatibilities between active substance and excipients occur. On the basis of IR spectra and the results of PCA and CA it was possible to demonstrate that the presence of lactose, β-cyclodextrin and meglumine in binary mixtures produce interactions with baclofen. The results were verified using differential scanning calorimetry, differential thermal analysis, thermogravimetry/differential thermogravimetry and X-ray powder diffraction analyses.

Experimental Methods for Studying the Hessdalen-Phenomenon in the Light of the Proposed Theories: A Comparative Overview

NASA Astrophysics Data System (ADS)

Teodorani, M.; Strand, E.

Unexplained plasma-like atmospheric `light balls' are observed at very low altitudes during alternate phases of maximum and minimum in the Hessdalen area, located in central Norway. Several theories are presented in order to explain the observed phenomenon; among these: piezo-electricity from rocks, atmospheric ionization triggered by solar activity and cosmic rays. The presented study is aimed at proposing the use of a dedicated instrumental set-up, research experimental procedures and methods in order to prove or disprove every single theory: in this context several kinds of observational techniques, measurement strategies and physical tests of tactical relevance are discussed in detail. An introduction on any considered theory is presented together with a detailed discussion regarding the subsequent experimental phase. For each specific theory brief descriptions of the observable parameters and of the essential instrumental choices and a detailed discussion of measurement procedures coupled with suitable flow-charts, are presented.

Physical cryptographic verification of nuclear warheads

DOE PAGES

Kemp, R. Scott; Danagoulian, Areg; Macdonald, Ruaridh R.; ...

2016-07-18

How does one prove a claim about a highly sensitive object such as a nuclear weapon without revealing information about the object? This paradox has challenged nuclear arms control for more than five decades. We present a mechanism in the form of an interactive proof system that can validate the structure and composition of an object, such as a nuclear warhead, to arbitrary precision without revealing either its structure or composition. We introduce a tomographic method that simultaneously resolves both the geometric and isotopic makeup of an object. We also introduce a method of protecting information using a provably securemore » cryptographic hash that does not rely on electronics or software. Finally, these techniques, when combined with a suitable protocol, constitute an interactive proof system that could reject hoax items and clear authentic warheads with excellent sensitivity in reasonably short measurement times.« less

Influence of nonlinear thermal radiation and viscous dissipation on three-dimensional flow of Jeffrey nano fluid over a stretching sheet in the presence of Joule heating

NASA Astrophysics Data System (ADS)

Ganesh Kumar, K.; Rudraswamy, N. G.; Gireesha, B. J.; Krishnamurthy, M. R.

2017-09-01

Present exploration discusses the combined effect of viscous dissipation and Joule heating on three dimensional flow and heat transfer of a Jeffrey nanofluid in the presence of nonlinear thermal radiation. Here the flow is generated over bidirectional stretching sheet in the presence of applied magnetic field by accounting thermophoresis and Brownian motion of nanoparticles. Suitable similarity transformations are employed to reduce the governing partial differential equations into coupled nonlinear ordinary differential equations. These nonlinear ordinary differential equations are solved numerically by using the Runge-Kutta-Fehlberg fourth-fifth order method with shooting technique. Graphically results are presented and discussed for various parameters. Validation of the current method is proved by comparing our results with the existing results under limiting situations. It can be concluded that combined effect of Joule and viscous heating increases the temperature profile and thermal boundary layer thickness.

Low thermal diffusivity measurements of thin films using mirage technique

NASA Astrophysics Data System (ADS)

Wong, P. K.; Fung, P. C. W.; Tam, H. L.

1998-12-01

Mirage technique is proved to be powerful in measurements of thermal diffusivity. Its contactless nature makes it suitable for delicate samples such as thin films and single crystals. However, as the damping of the thermal wave profile increases progressively upon the decrease in thermal diffusivity of the medium, mirage technique becomes more difficult to be applied to low thermal diffusivity measurements. Moreover influences from substrate signals make analysis difficult when the samples are thermally thin. Recently a thermal-wave-coupling method for mirage signal analysis [P. K. Wong, P. C. W. Fung, H. L. Tam, and J. Gao, Phys. Rev. B 51, 523 (1995)] was reported for thermal diffusivity measurements of thin film down to 60 nm thick. In this article we apply the thermal-wave-coupling method to thin films of low thermal diffusivity, especially polymer films. A new lower limit of thermal diffusivity measurable by mirage technique has been reached.

Saccadic eye movements analysis as a measure of drug effect on central nervous system function.

PubMed

Tedeschi, G; Quattrone, A; Bonavita, V

1986-04-01

Peak velocity (PSV) and duration (SD) of horizontal saccadic eye movements are demonstrably under the control of specific brain stem structures. Experimental and clinical evidence suggest the existence of an immediate premotor system for saccade generation located in the paramedian pontine reticular formation (PPRF). Effects on saccadic eye movements have been studied in normal volunteers with barbiturates, benzodiazepines, amphetamine and ethanol. On two occasions computer analysis of PSV, SD, saccade reaction time (SRT) and saccade accuracy (SA) was carried out in comparison with more traditional methods of assessment of human psychomotor performance like choice reaction time (CRT) and critical flicker fusion threshold (CFFT). The computer system proved to be a highly sensitive and objective method for measuring drug effect on central nervous system (CNS) function. It allows almost continuous sampling of data and appears to be particularly suitable for studying rapidly changing drug effects on the CNS.

Insect contamination protection for laminar flow surfaces

NASA Technical Reports Server (NTRS)

Croom, Cynthia C.; Holmes, Bruce J.

1986-01-01

The ability of modern aircraft surfaces to achieve laminar flow was well-accepted in recent years. Obtaining the maximum benefit of laminar flow for aircraft drag reduction requires maintaining minimum leading-edge contamination. Previously proposed insect contamination prevention methods have proved impractical due to cost, weight, or inconvenience. Past work has shown that insects will not adhere to water-wetted surfaces, but the large volumes of water required for protection rendered such a system impractical. The results of a flight experiment conducted by NASA to evaluate the performance of a porous leading-edge fluid discharge ice protection system operated as an insect contamination protections system are presented. In addition, these flights explored the environmental and atmospheric conditions most suitable for insect accumulation.

Lunar oxygen and metal for use in near-earth space - Magma electrolysis

NASA Technical Reports Server (NTRS)

Colson, Russell O.; Haskin, Larry A.

1990-01-01

The unique conditions on the moon, such as vacuum, absence of many reagents common on the earth, and presence of very nontraditional 'ores', suggest that a unique and nontraditional process for extracting materials from the ores may prove the most practical. An investigation has begun into unfluxed silicate electrolysis as a method for extracting oxygen, Fe, and Si from lunar regolith. The advantages of the process include simplicity of concept, absence of need to supply reagents from the earth, and low power and mass requirements for the processing plant. Disadvantages include the need for uninterrupted high temperature and the highly corrosive nature of the high-temperature silicate melts, which has made identifying suitable electrode and container materials difficult.

Direct high-performance liquid chromatographic determination of the enantiomeric purity of levodopa and methyldopa: comparison with pharmacopoeial polarimetric methods.

PubMed

Dolezalová, M; Tkaczyková, M

1999-03-01

Chiral high-performance liquid chromatography was employed for determination of the enantiomeric purity of levodopa and methyldopa. The determination of D-DOPA in levodopa was accomplished using a chiral ligand-exchange chromatograpy with an ordinary C18 column and a chiral mobile phase containing N,N-dimethyl-L-phenylalanine and Cu(II) acetate or by means of LC on a teicoplanin column in conjunction with ethanol-water (65:35, v/v). Both methods gave good performance, however, the latter was faster and more convenient and suitable for routine analyses. For the determination of D-methyldopa a LC method based on the use of a teicoplanin column in polar organic mode with methanol-acetic acid-triethylamine (1,000:0.05:0.05, v/v/v) mobile phase was developed. The precision, accuracy, linearity and selectivity were satisfactory. In comparison with pharmacopoeial polarimetric methods (according to the European Pharmacopoeia and the Pharmacopoea Bohemoslovaca), the LC methods proved to be much more sensitive giving detection limits 0.04% of D-DOPA and 0.3% of D-methyldopa.

A Simple RP-HPLC Method for Quantitation of Itopride HCl in Tablet Dosage Form.

PubMed

Thiruvengada, Rajan Vs; Mohamed, Saleem Ts; Ramkanth, S; Alagusundaram, M; Ganaprakash, K; Madhusudhana, Chetty C

2010-10-01

An isocratic reversed phase high-performance liquid chromatographic method with ultraviolet detection at 220 nm has been developed for the quantification of itopride hydrochloride in tablet dosage form. The quantification was carried out using C(8) column (250 mm × 4.6 mm), 5-μm particle size SS column. The mobile phase comprised of two solvents (Solvent A: buffer 1.4 mL ortho-phosphoric acid adjusted to pH 3.0 with triethyl amine and Solvent B: acetonitrile). The ratio of Solvent A: Solvent B was 75:25 v/v. The flow rate was 1.0 mL (-1)with UV detection at 220 nm. The method has been validated and proved to be robust. The calibration curve was linear in the concentration range of 80-120% with coefficient of correlation 0.9995. The percentage recovery for itopride HCl was 100.01%. The proposed method was validated for its selectivity, linearity, accuracy, and precision. The method was found to be suitable for the quality control of itopride HCl in tablet dosage formulation.

A Simple RP-HPLC Method for Quantitation of Itopride HCl in Tablet Dosage Form

PubMed Central

Thiruvengada, Rajan VS; Mohamed, Saleem TS; Ramkanth, S; Alagusundaram, M; Ganaprakash, K; Madhusudhana, Chetty C

2010-01-01

An isocratic reversed phase high-performance liquid chromatographic method with ultraviolet detection at 220 nm has been developed for the quantification of itopride hydrochloride in tablet dosage form. The quantification was carried out using C8 column (250 mm × 4.6 mm), 5-μm particle size SS column. The mobile phase comprised of two solvents (Solvent A: buffer 1.4 mL ortho-phosphoric acid adjusted to pH 3.0 with triethyl amine and Solvent B: acetonitrile). The ratio of Solvent A: Solvent B was 75:25 v/v. The flow rate was 1.0 mL -1with UV detection at 220 nm. The method has been validated and proved to be robust. The calibration curve was linear in the concentration range of 80-120% with coefficient of correlation 0.9995. The percentage recovery for itopride HCl was 100.01%. The proposed method was validated for its selectivity, linearity, accuracy, and precision. The method was found to be suitable for the quality control of itopride HCl in tablet dosage formulation. PMID:21264104

Spectrum of the Laplace-Beltrami operator and the phase structure of causal dynamical triangulations

NASA Astrophysics Data System (ADS)

Clemente, Giuseppe; D'Elia, Massimo

2018-06-01

We propose a new method to characterize the different phases observed in the nonperturbative numerical approach to quantum gravity known as causal dynamical triangulations. The method is based on the analysis of the eigenvalues and the eigenvectors of the Laplace-Beltrami operator computed on the triangulations: it generalizes previous works based on the analysis of diffusive processes and proves capable of providing more detailed information on the geometric properties of the triangulations. In particular, we apply the method to the analysis of spatial slices, showing that the different phases can be characterized by a new order parameter related to the presence or absence of a gap in the spectrum of the Laplace-Beltrami operator, and deriving an effective dimensionality of the slices at the different scales. We also propose quantities derived from the spectrum that could be used to monitor the running to the continuum limit around a suitable critical point in the phase diagram, if any is found.

Practical issues relating to soil column chromatography for sorption parameter determination.

PubMed

Bi, Erping; Schmidt, Torsten C; Haderlein, Stefan B

2010-08-01

Determination of sorption distribution coefficients (K(d)) of organic compounds by a dynamic soil column chromatography (SCC) method was developed and validated. Eurosoil 4, quartz, and alumina were chosen as exemplary packing materials. Heterocyclic aromatic compounds were selected in the validation of SCC. The prerequisites of SCC with regard to column dimension, packing procedure, and sample injection volume are discussed. Reproducible soil column packing was achieved by addition of a pre-column and an HPLC pump for subsequent compression of the packed material. Various methods to determine retention times from breakthrough curves are discussed and the use of the half mass method is recommended. To dilute soil with inert material can prevent column-clogging and help to complete experiments in a reasonable period of time. For the chosen probe compounds, quartz rather than alumina proved a suitable dilution material. Non-equilibrium issue can be overcome by conducting the experiments under different flowrates and/or performing numerical simulation. Copyright 2010 Elsevier Ltd. All rights reserved.

Implementation of direct LSC method for diesel samples on the fuel market.

PubMed

Krištof, Romana; Hirsch, Marko; Kožar Logar, Jasmina

2014-11-01

The European Union develops common EU policy and strategy on biofuels and sustainable bio-economy through several documents. The encouragement of biofuel's consumption is therefore the obligation of each EU member state. The situation in Slovenian fuel market is presented and compared with other EU countries in the frame of prescribed values from EU directives. Diesel is the most common fuel for transportation needs in Slovenia. The study was therefore performed on diesel. The sampling net was determined in accordance with the fuel consumption statistics of the country. 75 Sampling points were located on different types of roads. The quantity of bio-component in diesel samples was determined by direct LSC method through measurement of C-14 content. The measured values were in the range from 0 up to nearly 6 mass percentage of bio-component in fuel. The method has proved to be appropriate, suitable and effective for studies on the real fuel market. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessing rare earth elements in quartz rich geological samples.

PubMed

Santoro, A; Thoss, V; Ribeiro Guevara, S; Urgast, D; Raab, A; Mastrolitti, S; Feldmann, J

2016-01-01

Sodium peroxide (Na2O2) fusion coupled to Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS) measurements was used to rapidly screen quartz-rich geological samples for rare earth element (REE) content. The method accuracy was checked with a geological reference material and Instrumental Neutron Activation Analysis (INAA) measurements. The used mass-mode combinations presented accurate results (only exception being (157)Gd in He gas mode) with recovery of the geological reference material QLO-1 between 80% and 98% (lower values for Lu, Nd and Sm) and in general comparable to INAA measurements. Low limits of detection for all elements were achieved, generally below 10 pg g(-1), as well as measurement repeatability below 15%. Overall, the Na2O2/ICP-MS/MS method proved to be a suitable lab-based method to quickly and accurately screen rock samples originating from quartz-rich geological areas for rare earth element content; particularly useful if checking commercial viability. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Digital vs. analog hearing aids for children. Is there a method for making an objective comparison possible?].

PubMed

Prinz, I; Nubel, K; Gross, M

2002-09-01

Until now, the assumed benefits of digital hearing aids are reflected only in subjective descriptions by patients with hearing aids, but cannot be documented adequately by routine diagnostic methods. Seventeen schoolchildren with moderate severe bilateral symmetrical sensorineural hearing loss were examined in a double-blinded crossover study. Differences in performance between a fully digital hearing aid (DigiFocus compact/Oticon) and an analogous digitally programmable two-channel hearing aid were evaluated. Of the 17 children, 13 choose the digital and 4 the analogous hearing aid. In contrast to the clear subjective preferences for the fully digital hearing aid, we could not obtain any significant results with routine diagnostic methods. Using the "virtual hearing aid," a subjective comparison and speech recognition performance task yielded significant differences. The virtual hearing aid proved to be suitable for a direct comparison of different hearing aids and can be used for double-blind testing in a pediatric population.

Investigation of work-related disorders in truck drivers using RULA method.

PubMed

Massaccesi, M; Pagnotta, A; Soccetti, A; Masali, M; Masiero, C; Greco, F

2003-07-01

A high incidence of spinal disorders is observed in professional drivers; in particular, back and neck pain result in high rates of morbidity and low retirement age. A sample of 77 drivers, of rubbish-collection vehicles who sit in a standard posture and of road-washing vehicles, who drive with the neck and trunk flexed, bent and twisted, was studied using RULA, a method for the evaluation of the exposure to risk factors associated with work-related upper-limb disorders. Results showed a significant association between trunk and neck scores and all self-reported pains, aches or discomforts in the trunk or neck regions in all subjects. In particular, the neck score was significant in both postures, reflecting high loading of the neck. Significantly different posture scores were also recorded for drivers using an adjustable vs. a non-adjustable seat. In this first RULA study of the working posture of professional truck drivers, the method proved to be a suitable tool for the rapid evaluation of the loading of neck and trunk.

Decision Making and Systems Thinking: Educational Issues

ERIC Educational Resources Information Center

Yurtseven, M. Kudret; Buchanan, Walter W.

2016-01-01

Decision making in most universities is taught within the conventional OR/MS (Operations Research/Management Science) paradigm. This paradigm is known to be "hard" since it is consisted of mathematical tools, and normally suitable for solving structured problems. In complex situations the conventional OR/MS paradigm proves to be…

The Importance of Proving the Null

ERIC Educational Resources Information Center

Gallistel, C. R.

2009-01-01

Null hypotheses are simple, precise, and theoretically important. Conventional statistical analysis cannot support them; Bayesian analysis can. The challenge in a Bayesian analysis is to formulate a suitably vague alternative, because the vaguer the alternative is (the more it spreads out the unit mass of prior probability), the more the null is…

Evolutionary algorithms for the optimization of advective control of contaminated aquifer zones

NASA Astrophysics Data System (ADS)

Bayer, Peter; Finkel, Michael

2004-06-01

Simple genetic algorithms (SGAs) and derandomized evolution strategies (DESs) are employed to adapt well capture zones for the hydraulic optimization of pump-and-treat systems. A hypothetical contaminant site in a heterogeneous aquifer serves as an application template. On the basis of the results from numerical flow modeling, particle tracking is applied to delineate the pathways of the contaminants. The objective is to find the minimum pumping rate of up to eight recharge wells within a downgradient well placement area. Both the well coordinates and the pumping rates are subject to optimization, leading to a mixed discrete-continuous problem. This article discusses the ideal formulation of the objective function for which the number of particles and the total pumping rate are used as decision criteria. Boundary updating is introduced, which enables the reorganization of the decision space limits by the incorporation of experience from previous optimization runs. Throughout the study the algorithms' capabilities are evaluated in terms of the number of model runs which are needed to identify optimal and suboptimal solutions. Despite the complexity of the problem both evolutionary algorithm variants prove to be suitable for finding suboptimal solutions. The DES with weighted recombination reveals to be the ideal algorithm to find optimal solutions. Though it works with real-coded decision parameters, it proves to be suitable for adjusting discrete well positions. Principally, the representation of well positions as binary strings in the SGA is ideal. However, even if the SGA takes advantage of bookkeeping, the vital high discretization of pumping rates results in long binary strings, which escalates the model runs that are needed to find an optimal solution. Since the SGA string lengths increase with the number of wells, the DES gains superiority, particularly for an increasing number of wells. As the DES is a self-adaptive algorithm, it proves to be the more robust optimization method for the selected advective control problem than the SGA variants of this study, exhibiting a less stochastic search which is reflected in the minor variability of the found solutions.

A new efficient method to monitor precocious puberty nationwide in France.

PubMed

Rigou, Annabel; Le Moal, Joëlle; Léger, Juliane; Le Tertre, Alain; Carel, Jean-Claude

2018-02-01

Clinical precocious puberty (PP) is a disease, reputed to be on the increase and suspected to be linked to endocrine disrupting chemicals (EDC) exposure. Population-based epidemiological data are lacking in France and scarce elsewhere. We accessed the feasibility of monitoring PP nationwide in France in this context, using a nationwide existing database, the French National Health Insurance Information System. Here, we present the method we used with a step-by-step approach to build and select the most suitable indicator. We built three indicators reflecting the incidence of idiopathic central precocious puberty (ICPP), the most frequent form of PP, and we compared these indicators according to their strengths and weaknesses with respect to surveillance purposes. Monitoring ICPP in France proved feasible using a Drug reimbursement indicator. Our method is cost efficient and highly relevant in public health surveillance. Our step-by-step approach proved helpful to achieve this project and could be proposed for assessing the feasibility of monitoring health outcomes of interest using existing data bases. What is known: • Precocious puberty (PP) is suspected to be related to EDC exposure and it is believed to be on the increase in France and in others countries. • Very few epidemiologic data on PP are currently available in the world at the national scale. What is new: • This is the first study describing a method to monitor the most frequent form of PP, idiopathic central PP (ICPP) nationwide in a cost-efficient way, using health insurance databases. • This cost-effective method will allow to estimate and monitor the incidence of ICPP in France and to analyze spatial variations at a very precise scale, which will be very useful to examine the role of environmental exposures, especially to EDCs.

Determination of glyoxal and methylglyoxal in environmental and biological matrices by stir bar sorptive extraction with in-situ derivatization.

PubMed

Neng, N R; Cordeiro, C A A; Freire, A P; Nogueira, J M F

2007-10-26

Stir bar sorptive extraction with in-situ derivatization using 2,3-diaminonaphthalene (DAN) followed by liquid desorption and high performance liquid chromatography with diode array detection (SBSE(DAN)in-situ-LD-HPLC-DAD) was developed for the determination of glyoxal (Gly) and methylglyoxal (MGly) in environmental and biological matrices. DAN proved very good specificity as in-situ derivatising agent for Gly and MGly in aqueous media, allowing the formation of adducts with remarkable sensitivity, selectivity and the absence of photodegradation. Assays performed on spiked (1.0 microg L(-1)) water samples, under convenient experimental conditions, yielded recoveries of 96.2+/-7.9% for Gly and 96.1+/-6.4% for MGly. The analytical performance showed good accuracy, suitable precision (<12.0%), low detection limits (15 ng L(-1) for Gly and 25 ng L(-1) for MGly adducts) and excellent linear dynamic ranges (r2>0.99) from 0.1 to 120.0 microg L(-1). By using the standard addition method, the application of the present method to tap and swimming-pool water, beer, yeast cells suspension and urine samples allowed very good performance at the trace level. The proposed methodology proved to be a feasible alternative for routine quality control analysis, showing to be easy to implement, reliable, sensitive and with a low sample volume requirement to monitor Gly and MGly in environmental and biological matrices.

Validation of Reference Genes for Quantitative Expression Analysis by Real-Time RT-PCR in Four Lepidopteran Insects

PubMed Central

Teng, Xiaolu; Zhang, Zan; He, Guiling; Yang, Liwen; Li, Fei

2012-01-01

Quantitative real-time polymerase chain reaction (qPCR) is an efficient and widely used technique to monitor gene expression. Housekeeping genes (HKGs) are often empirically selected as the reference genes for data normalization. However, the suitability of HKGs used as the reference genes has been seldom validated. Here, six HKGs were chosen (actin A3, actin A1, GAPDH, G3PDH, E2F, rp49) in four lepidopteran insects Bombyx mori L. (Lepidoptera: Bombycidae), Plutella xylostella L. (Plutellidae), Chilo suppressalis Walker (Crambidae), and Spodoptera exigua Hübner (Noctuidae) to study their expression stability. The algorithms of geNorm, NormFinder, stability index, and ΔCt analysis were used to evaluate these HKGs. Across different developmental stages, actin A1 was the most stable in P. xylostella and C. suppressalis, but it was the least stable in B. mori and S. exigua. Rp49 and GAPDH were the most stable in B. mori and S. exigua, respectively. In different tissues, GAPDH, E2F, and Rp49 were the most stable in B. mori, S. exigua, and C. suppressalis, respectively. The relative abundances of Siwi genes estimated by 2-ΔΔCt method were tested with different HKGs as the reference gene, proving the importance of internal controls in qPCR data analysis. The results not only presented a list of suitable reference genes in four lepidopteran insects, but also proved that the expression stabilities of HKGs were different among evolutionarily close species. There was no single universal reference gene that could be used in all situations. It is indispensable to validate the expression of HKGs before using them as the internal control in qPCR. PMID:22938136

Validation of reference genes for quantitative expression analysis by real-time rt-PCR in four lepidopteran insects.

PubMed

Teng, Xiaolu; Zhang, Zan; He, Guiling; Yang, Liwen; Li, Fei

2012-01-01

Quantitative real-time polymerase chain reaction (qPCR) is an efficient and widely used technique to monitor gene expression. Housekeeping genes (HKGs) are often empirically selected as the reference genes for data normalization. However, the suitability of HKGs used as the reference genes has been seldom validated. Here, six HKGs were chosen (actin A3, actin A1, GAPDH, G3PDH, E2F, rp49) in four lepidopteran insects Bombyx mori L. (Lepidoptera: Bombycidae), Plutella xylostella L. (Plutellidae), Chilo suppressalis Walker (Crambidae), and Spodoptera exigua Hübner (Noctuidae) to study their expression stability. The algorithms of geNorm, NormFinder, stability index, and ΔCt analysis were used to evaluate these HKGs. Across different developmental stages, actin A1 was the most stable in P. xylostella and C. suppressalis, but it was the least stable in B. mori and S. exigua. Rp49 and GAPDH were the most stable in B. mori and S. exigua, respectively. In different tissues, GAPDH, E2F, and Rp49 were the most stable in B. mori, S. exigua, and C. suppressalis, respectively. The relative abundances of Siwi genes estimated by 2(-ΔΔCt) method were tested with different HKGs as the reference gene, proving the importance of internal controls in qPCR data analysis. The results not only presented a list of suitable reference genes in four lepidopteran insects, but also proved that the expression stabilities of HKGs were different among evolutionarily close species. There was no single universal reference gene that could be used in all situations. It is indispensable to validate the expression of HKGs before using them as the internal control in qPCR.

The coding region of the UFGT gene is a source of diagnostic SNP markers that allow single-locus DNA genotyping for the assessment of cultivar identity and ancestry in grapevine (Vitis vinifera L.)

PubMed Central

2013-01-01

Background Vitis vinifera L. is one of society’s most important agricultural crops with a broad genetic variability. The difficulty in recognizing grapevine genotypes based on ampelographic traits and secondary metabolites prompted the development of molecular markers suitable for achieving variety genetic identification. Findings Here, we propose a comparison between a multi-locus barcoding approach based on six chloroplast markers and a single-copy nuclear gene sequencing method using five coding regions combined with a character-based system with the aim of reconstructing cultivar-specific haplotypes and genotypes to be exploited for the molecular characterization of 157 V. vinifera accessions. The analysis of the chloroplast target regions proved the inadequacy of the DNA barcoding approach at the subspecies level, and hence further DNA genotyping analyses were targeted on the sequences of five nuclear single-copy genes amplified across all of the accessions. The sequencing of the coding region of the UFGT nuclear gene (UDP-glucose: flavonoid 3-0-glucosyltransferase, the key enzyme for the accumulation of anthocyanins in berry skins) enabled the discovery of discriminant SNPs (1/34 bp) and the reconstruction of 130 V. vinifera distinct genotypes. Most of the genotypes proved to be cultivar-specific, and only few genotypes were shared by more, although strictly related, cultivars. Conclusion On the whole, this technique was successful for inferring SNP-based genotypes of grapevine accessions suitable for assessing the genetic identity and ancestry of international cultivars and also useful for corroborating some hypotheses regarding the origin of local varieties, suggesting several issues of misidentification (synonymy/homonymy). PMID:24298902

Exponential instability in the fractional Calderón problem

NASA Astrophysics Data System (ADS)

Rüland, Angkana; Salo, Mikko

2018-04-01

In this paper we prove the exponential instability of the fractional Calderón problem and thus prove the optimality of the logarithmic stability estimate from Rüland and Salo (2017 arXiv:1708.06294). In order to infer this result, we follow the strategy introduced by Mandache in (2001 Inverse Problems 17 1435) for the standard Calderón problem. Here we exploit a close relation between the fractional Calderón problem and the classical Poisson operator. Moreover, using the construction of a suitable orthonormal basis, we also prove (almost) optimality of the Runge approximation result for the fractional Laplacian, which was derived in Rüland and Salo (2017 arXiv:1708.06294). Finally, in one dimension, we show a close relation between the fractional Calderón problem and the truncated Hilbert transform.

Determination of Carbonyl Compounds in Cork Agglomerates by GDME-HPLC-UV: Identification of the Extracted Compounds by HPLC-MS/MS.

PubMed

Brandão, Pedro Francisco; Ramos, Rui Miguel; Almeida, Paulo Joaquim; Rodrigues, José António

2017-02-08

A new approach is proposed for the extraction and determination of carbonyl compounds in solid samples, such as wood or cork materials. Cork products are used as building materials due to their singular characteristics; however, little is known about its aldehyde emission potential and content. Sample preparation was done by using a gas-diffusion microextraction (GDME) device for the direct extraction of volatile aldehydes and derivatization with 2,4-dinitrophenylhydrazine. Analytical determination of the extracts was done by HPLC-UV, with detection at 360 nm. The developed methodology proved to be a reliable tool for aldehyde determination in cork agglomerate samples with suitable method features. Mass spectrometry studies were performed for each sample, which enabled the identification, in the extracts, of the derivatization products of a total of 13 aldehydes (formaldehyde, acetaldehyde, furfural, propanal, 5-methylfurfural, butanal, benzaldehyde, pentanal, hexanal, trans-2-heptenal, heptanal, octanal, and trans-2-nonenal) and 4 ketones (3-hydroxy-2-butanone, acetone, cyclohexanone, and acetophenone). This new analytical methodology simultaneously proved to be consistent for the identification and determination of aldehydes in cork agglomerates and a very simple and straightforward procedure.

On the probability density function and characteristic function moments of image steganalysis in the log prediction error wavelet subband

NASA Astrophysics Data System (ADS)

Bao, Zhenkun; Li, Xiaolong; Luo, Xiangyang

2017-01-01

Extracting informative statistic features is the most essential technical issue of steganalysis. Among various steganalysis methods, probability density function (PDF) and characteristic function (CF) moments are two important types of features due to the excellent ability for distinguishing the cover images from the stego ones. The two types of features are quite similar in definition. The only difference is that the PDF moments are computed in the spatial domain, while the CF moments are computed in the Fourier-transformed domain. Then, the comparison between PDF and CF moments is an interesting question of steganalysis. Several theoretical results have been derived, and CF moments are proved better than PDF moments in some cases. However, in the log prediction error wavelet subband of wavelet decomposition, some experiments show that the result is opposite and lacks a rigorous explanation. To solve this problem, a comparison result based on the rigorous proof is presented: the first-order PDF moment is proved better than the CF moment, while the second-order CF moment is better than the PDF moment. It tries to open the theoretical discussion on steganalysis and the question of finding suitable statistical features.

Green Pharmaceutical Analysis of Drugs Coformulated with Highly Different Concentrations Using Spiking and Manipulation of Their Ratio Spectra.

PubMed

Ayoub, Bassam M

2017-07-01

Introducing green analysis to pharmaceutical products is considered a significant approach to preserving the environment. This method can be an environmentally friendly alternative to the existing methods, accompanied by a validated automated procedure for the analysis of a drug with the lowest possible number of samples. Different simple spectrophotometric methods were developed for the simultaneous determination of empagliflozin (EG) and metformin (MT) by manipulating their ratio spectra in their application on a recently approved pharmaceutical combination, Synjardy tablets. A spiking technique was used to increase the concentration of EG in samples prepared from the tablets to allow for the simultaneous determination of EG with MT without prior separation. Validation parameters according to International Conference on Harmonization guidelines were acceptable over a concentration range of 2-12 μg/mL for both drugs using derivative ratio and ratio subtraction coupled with extended ratio subtraction. The optimized methods were compared using one-way analysis of variance and proved to be suitable as ecofriendly approaches for industrial QC laboratories.

Determination of flavonoids in cultivated sugarcane leaves, bagasse, juice and in transgenic sugarcane by liquid chromatography-UV detection.

PubMed

Colombo, Renata; Lanças, Fernando M; Yariwake, Janete H

2006-01-20

A high-performance liquid chromatography (HPLC) method with photo-diode array (DAD) detection was developed to separate and quantify flavonoids in sugarcane leaves and bagasse (= the crushed sugarcane refuse from juice extraction), and in sugarcane juice. Sugarcane flavonoids consist of a complex mixture of aglycones and glycosides (including flavonolignan glycosides), and the HPLC-UV method herein proposed is suitable for their quantification as total flavonoids. This method was applied to analyze samples of cultivated sugarcane, commercial juice and transgenic sugarcane leaves. Sugarcane leaves proved a promising source of flavonoids: an average of 1.10 mg of total flavonoids/g plant material was found in fresh leaves. Moreover, the flavonoid content of sugarcane juice (0.6 mg/mL) is comparable to other food sources of flavonoids previously reported. Transgenic sugarcane leaves ("Bowman-Birk" and "Kunitz") were compared with non-modified ("control") plant samples using the proposed HPLC-UV method, which indicated that the content of total flavonoids in transgenic plants is different from that in non-modified sugarcane.

A user-friendly SSVEP-based brain-computer interface using a time-domain classifier.

PubMed

Luo, An; Sullivan, Thomas J

2010-04-01

We introduce a user-friendly steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) system. Single-channel EEG is recorded using a low-noise dry electrode. Compared to traditional gel-based multi-sensor EEG systems, a dry sensor proves to be more convenient, comfortable and cost effective. A hardware system was built that displays four LED light panels flashing at different frequencies and synchronizes with EEG acquisition. The visual stimuli have been carefully designed such that potential risk to photosensitive people is minimized. We describe a novel stimulus-locked inter-trace correlation (SLIC) method for SSVEP classification using EEG time-locked to stimulus onsets. We studied how the performance of the algorithm is affected by different selection of parameters. Using the SLIC method, the average light detection rate is 75.8% with very low error rates (an 8.4% false positive rate and a 1.3% misclassification rate). Compared to a traditional frequency-domain-based method, the SLIC method is more robust (resulting in less annoyance to the users) and is also suitable for irregular stimulus patterns.

The Development and Application of a Method to Quantify the Quality of Cryoprotectant Conditions Using Standard Area Detector X-Ray Images

NASA Technical Reports Server (NTRS)

McFerrin, Michael; Snell, Edward; Curreri, Peter A. (Technical Monitor)

2002-01-01

An X-ray based method for determining cryoprotectant concentrations necessary to protect solutions from crystalline ice formation was developed. X-ray images from a CCD area detector were integrated as powder patterns and quantified by determining the standard deviation of the slope of the normalized intensity curve in the resolution range where ice rings are known to occur. The method was tested determining the concentrations of glycerol, PEG400, ethylene glycol and 1,2-propanediol necessary to form an amorphous glass at 1OOK with each of the 98 crystallization solutions of Crystal Screens I and II (Hampton Research, Laguna Hills, California, USA). For conditions that required glycerol concentrations of 35% or above cryoprotectant conditions using 2,3-butanediol were determined. The method proved to be remarkably accurate. The results build on the work of [Garman and Mitchell] and extend the number, of suitable starting conditions to alternative cryoprotectants. In particular, 1,2-propanediol has emerged as a particularly good additive for glass formation upon flash cooling.

The Assessment of Cognitive Development in Blind Infants and Preschoolers.

ERIC Educational Resources Information Center

Brambring, M.; Troster, H.

1994-01-01

This study evaluated the Bielefeld Developmental Test for Blind Infants and Preschoolers by comparing cognitive performance of blind and sighted children (ages three and four). Results indicated that even this test (with "blind-neutral" items) did not permit a fair comparative assessment, though it did prove suitable for within-group…

Variational Solutions and Random Dynamical Systems to SPDEs Perturbed by Fractional Gaussian Noise

PubMed Central

Zeng, Caibin; Yang, Qigui; Cao, Junfei

2014-01-01

This paper deals with the following type of stochastic partial differential equations (SPDEs) perturbed by an infinite dimensional fractional Brownian motion with a suitable volatility coefficient Φ: dX(t) = A(X(t))dt+Φ(t)dB H(t), where A is a nonlinear operator satisfying some monotonicity conditions. Using the variational approach, we prove the existence and uniqueness of variational solutions to such system. Moreover, we prove that this variational solution generates a random dynamical system. The main results are applied to a general type of nonlinear SPDEs and the stochastic generalized p-Laplacian equation. PMID:24574903

Assessment of the safety of foods derived from genetically modified (GM) crops.

PubMed

König, A; Cockburn, A; Crevel, R W R; Debruyne, E; Grafstroem, R; Hammerling, U; Kimber, I; Knudsen, I; Kuiper, H A; Peijnenburg, A A C M; Penninks, A H; Poulsen, M; Schauzu, M; Wal, J M

2004-07-01

This paper provides guidance on how to assess the safety of foods derived from genetically modified crops (GM crops); it summarises conclusions and recommendations of Working Group 1 of the ENTRANSFOOD project. The paper provides an approach for adapting the test strategy to the characteristics of the modified crop and the introduced trait, and assessing potential unintended effects from the genetic modification. The proposed approach to safety assessment starts with the comparison of the new GM crop with a traditional counterpart that is generally accepted as safe based on a history of human food use (the concept of substantial equivalence). This case-focused approach ensures that foods derived from GM crops that have passed this extensive test-regime are as safe and nutritious as currently consumed plant-derived foods. The approach is suitable for current and future GM crops with more complex modifications. First, the paper reviews test methods developed for the risk assessment of chemicals, including food additives and pesticides, discussing which of these methods are suitable for the assessment of recombinant proteins and whole foods. Second, the paper presents a systematic approach to combine test methods for the safety assessment of foods derived from a specific GM crop. Third, the paper provides an overview on developments in this area that may prove of use in the safety assessment of GM crops, and recommendations for research priorities. It is concluded that the combination of existing test methods provides a sound test-regime to assess the safety of GM crops. Advances in our understanding of molecular biology, biochemistry, and nutrition may in future allow further improvement of test methods that will over time render the safety assessment of foods even more effective and informative. Copryright 2004 Elsevier Ltd.

Numerical simulation of cavitation flow characteristic on Pelton turbine bucket surface

NASA Astrophysics Data System (ADS)

Zeng, C. J.; Xiao, Y. X.; Zhu, W.; Yao, Y. Y.; Wang, Z. W.

2015-01-01

The internal flow in the rotating bucket of Pelton turbine is free water sheet flow with moving boundary. The runner operates under atmospheric and the cavitation in the bucket is still a controversial problem. While more and more field practice proved that there exists cavitation in the Pelton turbine bucket and the cavitation erosion may occur at the worst which will damage the bucket. So a well prediction about the cavitation flow on the bucket surface of Pelton turbine and the followed cavitation erosion characteristic can effectively guide the optimization of Pelton runner bucket and the stable operation of unit. This paper will investigate the appropriate numerical model and method for the unsteady 3D water-air-vapour multiphase cavitation flow which may occur on the Pelton bucket surface. The computational domain will include the nozzle pipe flow, semi-free surface jet and runner domain. Via comparing the numerical results of different turbulence, cavity and multiphase models, this paper will determine the suitable numerical model and method for the simulation of cavitation on the Pelton bucket surface. In order to investigate the conditions corresponding to the cavitation phenomena on the bucket surface, this paper will adopt the suitable model to simulate the various operational conditions of different water head and needle travel. Then, the characteristics of cavitation flow the development process of cavitation will be analysed in in great detail.

Estimation of Spatiotemporal Sensitivity Using Band-limited Signals with No Additional Acquisitions for k-t Parallel Imaging.

PubMed

Takeshima, Hidenori; Saitoh, Kanako; Nitta, Shuhei; Shiodera, Taichiro; Takeguchi, Tomoyuki; Bannae, Shuhei; Kuhara, Shigehide

2018-03-13

Dynamic MR techniques, such as cardiac cine imaging, benefit from shorter acquisition times. The goal of the present study was to develop a method that achieves short acquisition times, while maintaining a cost-effective reconstruction, for dynamic MRI. k - t sensitivity encoding (SENSE) was identified as the base method to be enhanced meeting these two requirements. The proposed method achieves a reduction in acquisition time by estimating the spatiotemporal (x - f) sensitivity without requiring the acquisition of the alias-free signals, typical of the k - t SENSE technique. The cost-effective reconstruction, in turn, is achieved by a computationally efficient estimation of the x - f sensitivity from the band-limited signals of the aliased inputs. Such band-limited signals are suitable for sensitivity estimation because the strongly aliased signals have been removed. For the same reduction factor 4, the net reduction factor 4 for the proposed method was significantly higher than the factor 2.29 achieved by k - t SENSE. The processing time is reduced from 4.1 s for k - t SENSE to 1.7 s for the proposed method. The image quality obtained using the proposed method proved to be superior (mean squared error [MSE] ± standard deviation [SD] = 6.85 ± 2.73) compared to the k - t SENSE case (MSE ± SD = 12.73 ± 3.60) for the vertical long-axis (VLA) view, as well as other views. In the present study, k - t SENSE was identified as a suitable base method to be improved achieving both short acquisition times and a cost-effective reconstruction. To enhance these characteristics of base method, a novel implementation is proposed, estimating the x - f sensitivity without the need for an explicit scan of the reference signals. Experimental results showed that the acquisition, computational times and image quality for the proposed method were improved compared to the standard k - t SENSE method.

Assessing embryo development using swept source optical coherence tomography

NASA Astrophysics Data System (ADS)

Caujolle, S.; Cernat, R.; Silvestri, G.; Marques, M. J.; Bradu, A.; Feuchter, T.; Robinson, G.; Griffin, D.; Podoleanu, A.

2018-03-01

A detailed assessment of embryo development would assist biologists with selecting the most suitable embryos for transfer leading to higher pregnancy rates. Currently, only low resolution microscopy is employed to perform this assessment. Although this method delivers some information on the embryo surface morphology, no specific details are shown related to its inner structure. Using a Master-Slave Swept-Source Optical Coherence Tomography (SS-OCT), images of bovine embryos from day 7 after fertilization were collected from different depths. The dynamic changes inside the embryos were examined, in detail and in real-time from several depths. To prove our ability to characterize the morphology, a single embryo was imaged over 26 hours. The embryo was deprived of its life support environment, leading to its death. Over this period, clear morphological changes were observed.

INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Superlattice Patterns in Coupled Turing Systems

NASA Astrophysics Data System (ADS)

Liu, Fu-Cheng; He, Ya-Feng; Pan, Yu-Yang

2010-05-01

In this paper, superlattice patterns have been investigated by using a two linearly coupled Brusselator model. It is found that superlattice patterns can only be induced in the sub-system with the short wavelength. Three different coupling methods have been used in order to investigate the mode interaction between the two Turing modes. It is proved in the simulations that interaction between activators in the two sub-systems leads to spontaneous formation of black eye pattern and/or white eye patterns while interaction between inhibitors leads to spontaneous formation of super-hexagonal pattern. It is also demonstrated that the same symmetries of the two modes and suitable wavelength ratio of the two modes should also be satisfied to form superlattice patterns.

State of Charge estimation of lithium ion battery based on extended Kalman filtering algorithm

NASA Astrophysics Data System (ADS)

Yang, Fan; Feng, Yiming; Pan, Binbiao; Wan, Renzhuo; Wang, Jun

2017-08-01

Accurate estimation of state-of-charge (SOC) for lithium ion battery is crucial for real-time diagnosis and prognosis in green energy vehicles. In this paper, a state space model of the battery based on Thevenin model is adopted. The strategy of estimating state of charge (SOC) based on extended Kalman fil-ter is presented, as well as to combine with ampere-hour counting (AH) and open circuit voltage (OCV) methods. The comparison between simulation and experiments indicates that the model’s performance matches well with that of lithium ion battery. The algorithm of extended Kalman filter keeps a good accura-cy precision and less dependent on its initial value in full range of SOC, which is proved to be suitable for online SOC estimation.

Fluorometric enzymatic assay of L-arginine

NASA Astrophysics Data System (ADS)

Stasyuk, Nataliya; Gayda, Galina; Yepremyan, Hasmik; Stepien, Agnieszka; Gonchar, Mykhailo

2017-01-01

The enzymes of L-arginine (further - Arg) metabolism are promising tools for elaboration of selective methods for quantitative Arg analysis. In our study we propose an enzymatic method for Arg assay based on fluorometric monitoring of ammonia, a final product of Arg splitting by human liver arginase I (further - arginase), isolated from the recombinant yeast strain, and commercial urease. The selective analysis of ammonia (at 415 nm under excitation at 360 nm) is based on reaction with o-phthalaldehyde (OPA) in the presence of sulfite in alkali medium: these conditions permit to avoid the reaction of OPA with any amino acid. A linearity range of the fluorometric arginase-urease-OPA method is from 100 nM to 6 μМ with a limit of detection of 34 nM Arg. The method was used for the quantitative determination of Arg in the pooled sample of blood serum. The obtained results proved to be in a good correlation with the reference enzymatic method and literature data. The proposed arginase-urease-OPA method being sensitive, economical, selective and suitable for both routine and micro-volume formats, can be used in clinical diagnostics for the simultaneous determination of Arg as well as urea and ammonia in serum samples.

Fast Constrained Spectral Clustering and Cluster Ensemble with Random Projection

PubMed Central

Liu, Wenfen

2017-01-01

Constrained spectral clustering (CSC) method can greatly improve the clustering accuracy with the incorporation of constraint information into spectral clustering and thus has been paid academic attention widely. In this paper, we propose a fast CSC algorithm via encoding landmark-based graph construction into a new CSC model and applying random sampling to decrease the data size after spectral embedding. Compared with the original model, the new algorithm has the similar results with the increase of its model size asymptotically; compared with the most efficient CSC algorithm known, the new algorithm runs faster and has a wider range of suitable data sets. Meanwhile, a scalable semisupervised cluster ensemble algorithm is also proposed via the combination of our fast CSC algorithm and dimensionality reduction with random projection in the process of spectral ensemble clustering. We demonstrate by presenting theoretical analysis and empirical results that the new cluster ensemble algorithm has advantages in terms of efficiency and effectiveness. Furthermore, the approximate preservation of random projection in clustering accuracy proved in the stage of consensus clustering is also suitable for the weighted k-means clustering and thus gives the theoretical guarantee to this special kind of k-means clustering where each point has its corresponding weight. PMID:29312447

Comparing memory-efficient genome assemblers on stand-alone and cloud infrastructures.

PubMed

Kleftogiannis, Dimitrios; Kalnis, Panos; Bajic, Vladimir B

2013-01-01

A fundamental problem in bioinformatics is genome assembly. Next-generation sequencing (NGS) technologies produce large volumes of fragmented genome reads, which require large amounts of memory to assemble the complete genome efficiently. With recent improvements in DNA sequencing technologies, it is expected that the memory footprint required for the assembly process will increase dramatically and will emerge as a limiting factor in processing widely available NGS-generated reads. In this report, we compare current memory-efficient techniques for genome assembly with respect to quality, memory consumption and execution time. Our experiments prove that it is possible to generate draft assemblies of reasonable quality on conventional multi-purpose computers with very limited available memory by choosing suitable assembly methods. Our study reveals the minimum memory requirements for different assembly programs even when data volume exceeds memory capacity by orders of magnitude. By combining existing methodologies, we propose two general assembly strategies that can improve short-read assembly approaches and result in reduction of the memory footprint. Finally, we discuss the possibility of utilizing cloud infrastructures for genome assembly and we comment on some findings regarding suitable computational resources for assembly.

Bell's Theorem and Einstein's "Spooky Actions" from a Simple Thought Experiment

ERIC Educational Resources Information Center

Kuttner, Fred; Rosenblum, Bruce

2010-01-01

In 1964 John Bell proved a theorem allowing the experimental test of whether what Einstein derided as "spooky actions at a distance" actually exist. We will see that they "do". Bell's theorem can be displayed with a simple, nonmathematical thought experiment suitable for a physics course at "any" level. And a simple, semi-classical derivation of…

Identification and Small Sample Estimation of Thurstone's Unrestricted Model for Paired Comparisons Data

ERIC Educational Resources Information Center

Maydeu-Olivares, Alberto; Hernandez, Adolfo

2007-01-01

The interpretation of a Thurstonian model for paired comparisons where the utilities' covariance matrix is unrestricted proved to be difficult due to the comparative nature of the data. We show that under a suitable constraint the utilities' correlation matrix can be estimated, yielding a readily interpretable solution. This set of identification…

The U.C.C. (Sales) as an Introductory Law School Course.

ERIC Educational Resources Information Center

Brown, Ronald Benton

1980-01-01

A provisional admissions program at Nova University Law Center allows students who do not qualify for admission to take two summer courses to prove their ability to succeed. One of the courses offered, Commercial Transactions I (Sales), which covers parts of the Uniform Commercial Code, is described and its suitability for beginning law students…

A Field Test for Upper Body Strength and Endurance.

ERIC Educational Resources Information Center

Nelson, Jack K.; And Others

1991-01-01

Researchers studied the reliability of the modified push-up test in measuring upper body strength and endurance in elementary through college students. It also examined the accuracy of partner scoring. The test proved much easier to administer than the regular floor push-up. It was valid and reliable for all students and suitable for partner…

Case study of a floor-cleaning robot

NASA Astrophysics Data System (ADS)

Branch, Allan C.

1998-01-01

Developing the technologies suitable of ra high level robotic application such as cleaning a floor has proved extremely difficult. Developing the robot mobility technology has been a stumbling block and developing and integrating the applications technology to the machine and the mobility technology has also been a difficult stage in this quest, but doing so in a cost effective and realistic manner suitable for the market place and to compete with humans and manually operated machines has been the most difficult of all. This paper describes one of these quests spanning a 14 year period and resulting in what is hoped will be the world's first commercially manufactured household robot vacuum cleaner.

Modulation selection for visible light communications using lighting LEDs

NASA Astrophysics Data System (ADS)

Siuzdak, Jerzy

2015-09-01

The paper analyzes suitability of various spectrally efficient modulations (PAM, CAP, OFDM/DMT) in a VLC system using lighting LEDs as a transmitter. Although under ideal conditions all modulation have similar efficiency i.e. they produce similar throughputs with a given BER, their practical performances are different. For example, the level of nonlinear distortions generated by each modulation is the least for PAM and by far the greatest for OFDM/DMT locating CAP in the middle. The suitability of various OFDM/DMT variants in a VLC LED link was also analyzed proving that the asymmetrically clipped (ACO) OFDM has a worse performance as compared with DC biased (DCO) OFDM.

Multiplicative Multitask Feature Learning

PubMed Central

Wang, Xin; Bi, Jinbo; Yu, Shipeng; Sun, Jiangwen; Song, Minghu

2016-01-01

We investigate a general framework of multiplicative multitask feature learning which decomposes individual task’s model parameters into a multiplication of two components. One of the components is used across all tasks and the other component is task-specific. Several previous methods can be proved to be special cases of our framework. We study the theoretical properties of this framework when different regularization conditions are applied to the two decomposed components. We prove that this framework is mathematically equivalent to the widely used multitask feature learning methods that are based on a joint regularization of all model parameters, but with a more general form of regularizers. Further, an analytical formula is derived for the across-task component as related to the task-specific component for all these regularizers, leading to a better understanding of the shrinkage effects of different regularizers. Study of this framework motivates new multitask learning algorithms. We propose two new learning formulations by varying the parameters in the proposed framework. An efficient blockwise coordinate descent algorithm is developed suitable for solving the entire family of formulations with rigorous convergence analysis. Simulation studies have identified the statistical properties of data that would be in favor of the new formulations. Extensive empirical studies on various classification and regression benchmark data sets have revealed the relative advantages of the two new formulations by comparing with the state of the art, which provides instructive insights into the feature learning problem with multiple tasks. PMID:28428735

Control of the repeatability of high frequency multibeam echosounder backscatter by using natural reference areas

NASA Astrophysics Data System (ADS)

Roche, Marc; Degrendele, Koen; Vrignaud, Christophe; Loyer, Sophie; Le Bas, Tim; Augustin, Jean-Marie; Lurton, Xavier

2018-06-01

The increased use of backscatter measurements in time series for environmental monitoring necessitates the comparability of individual results. With the current lack of pre-calibrated multibeam echosounder systems for absolute backscatter measurement, a pragmatic solution is the use of natural reference areas for ensuring regular assessment of the backscatter measurement repeatability. This method mainly relies on the assumption of a sufficiently stable reference area regarding its backscatter signature. The aptitude of a natural area to provide a stable and uniform backscatter response must be carefully considered and demonstrated by a sufficiently long time-series of measurements. Furthermore, this approach requires a strict control of the acquisition and processing parameters. If all these conditions are met, stability check and relative calibration of a system are possible by comparison with the averaged backscatter values for the area. Based on a common multibeam echosounder and sampling campaign completed by available bathymetric and backscatter time series, the suitability as a backscatter reference area of three different candidates was evaluated. Two among them, Carré Renard and Kwinte, prove to be excellent choices, while the third one, Western Solent, lacks sufficient data over time, but remains a valuable candidate. The case studies and the available backscatter data on these areas prove the applicability of this method. The expansion of the number of commonly used reference areas and the growth of the number of multibeam echosounder controlled thereon could greatly contribute to the further development of quantitative applications based on multibeam echosounder backscatter measurements.

On the Structure of {L^∞}-Entropy Solutions to Scalar Conservation Laws in One-Space Dimension

NASA Astrophysics Data System (ADS)

Bianchini, S.; Marconi, E.

2017-10-01

We prove that if u is the entropy solution to a scalar conservation law in one space dimension, then the entropy dissipation is a measure concentrated on countably many Lipschitz curves. This result is a consequence of a detailed analysis of the structure of the characteristics. In particular, the characteristic curves are segments outside a countably 1-rectifiable set and the left and right traces of the solution exist in a C 0-sense up to the degeneracy due to the segments where {f''=0}. We prove also that the initial data is taken in a suitably strong sense and we give some examples which show that these results are sharp.

Reference-free Shack-Hartmann wavefront sensor.

PubMed

Zhao, Liping; Guo, Wenjiang; Li, Xiang; Chen, I-Ming

2011-08-01

The traditional Shack-Hartmann wavefront sensing (SHWS) system measures the wavefront slope by calculating the centroid shift between the sample and a reference piece, and then the wavefront is reconstructed by a suitable iterative reconstruction method. Because of the necessity of a reference, many issues are brought up, which limit the system in most applications. This Letter proposes a reference-free wavefront sensing (RFWS) methodology, and an RFWS system is built up where wavefront slope changes are measured by introducing a lateral disturbance to the sampling aperture. By using Southwell reconstruction two times to process the measured data, the form of the wavefront at the sampling plane can be well reconstructed. A theoretical simulation platform of RFWS is established, and various surface forms are investigated. Practical measurements with two measurement systems-SHWS and our RFWS-are conducted, analyzed, and compared. All the simulation and measurement results prove and demonstrate the correctness and effectiveness of the method. © 2011 Optical Society of America

Quadratic stabilisability of multi-agent systems under switching topologies

NASA Astrophysics Data System (ADS)

Guan, Yongqiang; Ji, Zhijian; Zhang, Lin; Wang, Long

2014-12-01

This paper addresses the stabilisability of multi-agent systems (MASs) under switching topologies. Necessary and/or sufficient conditions are presented in terms of graph topology. These conditions explicitly reveal how the intrinsic dynamics of the agents, the communication topology and the external control input affect stabilisability jointly. With the appropriate selection of some agents to which the external inputs are applied and the suitable design of neighbour-interaction rules via a switching topology, an MAS is proved to be stabilisable even if so is not for each of uncertain subsystem. In addition, a method is proposed to constructively design a switching rule for MASs with norm-bounded time-varying uncertainties. The switching rules designed via this method do not rely on uncertainties, and the switched MAS is quadratically stabilisable via decentralised external self-feedback for all uncertainties. With respect to applications of the stabilisability results, the formation control and the cooperative tracking control are addressed. Numerical simulations are presented to demonstrate the effectiveness of the proposed results.

Numerical investigation of polarization insensitive two-mode division (De)multiplexer based on an asymmetric directional coupler

NASA Astrophysics Data System (ADS)

Truong, Cao Dung; Trinh, M. Tuan; Dang, Hoai Bac; Nguyen, Van Tho

2017-02-01

We propose a polarization insensitive two-mode division (de)multiplexer based on a silicon-on-insulator platform operating with a broadband, low insertion and scattering loss, and small crosstalk. By using an asymmetric directional coupler, two-mode (de)multiplexing functions for both polarization TE and TM states can be realized by the numerical simulation. Simulated results using a three dimensional beam propagation method (3D-BPM) incorporated with an effective index method (EIM) show high performance of the device with an operation efficiency above 81.2% (i.e., insertion loss is less than 0.9 dB) in the range of ±5 nm around the central wavelength of 1550 nm. Fabrication tolerances also have proved suitability to current manufacture technologies for the planar waveguides. Besides a low scattering loss of the sidewall roughness and a little influence of dispersion, a small footprint can bring the device to applications of high bitrate and compact on-chip silicon photonic integrated circuits.

An Indoor Positioning Method for Smartphones Using Landmarks and PDR.

PubMed

Wang, Xi; Jiang, Mingxing; Guo, Zhongwen; Hu, Naijun; Sun, Zhongwei; Liu, Jing

2016-12-15

Recently location based services (LBS) have become increasingly popular in indoor environments. Among these indoor positioning techniques providing LBS, a fusion approach combining WiFi-based and pedestrian dead reckoning (PDR) techniques is drawing more and more attention of researchers. Although this fusion method performs well in some cases, it still has some limitations, such as heavy computation and inconvenience for real-time use. In this work, we study map information of a given indoor environment, analyze variations of WiFi received signal strength (RSS), define several kinds of indoor landmarks, and then utilize these landmarks to correct accumulated errors derived from PDR. This fusion scheme, called Landmark-aided PDR (LaP), is proved to be light-weight and suitable for real-time implementation by running an Android application designed for the experiment. We compared LaP with other PDR-based fusion approaches. Experimental results show that the proposed scheme can achieve a significant improvement with an average accuracy of 2.17 m.

An Indoor Positioning Method for Smartphones Using Landmarks and PDR †

PubMed Central

Wang, Xi; Jiang, Mingxing; Guo, Zhongwen; Hu, Naijun; Sun, Zhongwei; Liu, Jing

2016-01-01

Recently location based services (LBS) have become increasingly popular in indoor environments. Among these indoor positioning techniques providing LBS, a fusion approach combining WiFi-based and pedestrian dead reckoning (PDR) techniques is drawing more and more attention of researchers. Although this fusion method performs well in some cases, it still has some limitations, such as heavy computation and inconvenience for real-time use. In this work, we study map information of a given indoor environment, analyze variations of WiFi received signal strength (RSS), define several kinds of indoor landmarks, and then utilize these landmarks to correct accumulated errors derived from PDR. This fusion scheme, called Landmark-aided PDR (LaP), is proved to be light-weight and suitable for real-time implementation by running an Android application designed for the experiment. We compared LaP with other PDR-based fusion approaches. Experimental results show that the proposed scheme can achieve a significant improvement with an average accuracy of 2.17 m. PMID:27983670

The question of organ procurement: beyond charity.

PubMed

Kreis, Henri

2005-07-01

Over the past 15 years, the shortage of organs for transplantation has worsened. This has forced clinicians to review alternative approaches to organ procurement. These new approaches, however, may have serious implications both for patients and for society as a whole. Ever since the first cadaver organs were used for transplantation, organ procurement has relied on the altruism and goodwill of donors. It now appears that this 40-year-old policy is proving unsuccessful. In order to increase the availability of suitable organs and allow cadaver organ transplantation to continue, it is time to consider new strategies other than donation. Among all the potential methods of organ procurement, including donation, abandonment, sale and societal appropriation, only the latter has never been ethically discussed or implemented. This article considers a variant of this approach defined as 'conditional societal appropriation' as an ethically acceptable possibility. It has the potential to become the principle method for obtaining the necessary organs for transplantation in the near future.

Recent Advances in 3D Printing of Aliphatic Polyesters.

PubMed

Chiulan, Ioana; Frone, Adriana Nicoleta; Brandabur, Călin; Panaitescu, Denis Mihaela

2017-12-24

3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

Respiration-rate estimation of a moving target using impulse-based ultra wideband radars.

PubMed

Sharafi, Azadeh; Baboli, Mehran; Eshghi, Mohammad; Ahmadian, Alireza

2012-03-01

Recently, Ultra-wide band signals have become attractive for their particular advantage of having high spatial resolution and good penetration ability which makes them suitable in medical applications. One of these applications is wireless detection of heart rate and respiration rate. Two hypothesis of static environment and fixed patient are considered in the method presented in previous literatures which are not valid for long term monitoring of ambulant patients. In this article, a new method to detect the respiration rate of a moving target is presented. The first algorithm is applied to the simulated and experimental data for detecting respiration rate of a fixed target. Then, the second algorithm is developed to detect respiration rate of a moving target. The proposed algorithm uses correlation for body movement cancellation, and then detects the respiration rate based on energy in frequency domain. The results of algorithm prove an accuracy of 98.4 and 97% in simulated and experimental data, respectively.

Direct Detection of Potential Pyrethroids in Yangtze River via an Imprinted Multilayer Phosphorescence Probe.

PubMed

Chen, Li; Lv, Xiaodong; Dai, Jiangdong; Sun, Lin; Huo, Pengwei; Li, Chunxiang; Yan, Yongsheng

2018-01-01

A novel tailored multilayer probe for monitoring potential pyrethroids in the Yangtze River was proposed. The room-temperature phosphorescence method was applied to realize a detection strategy that is superior to the fluorescence method. Efficient Mn-doped ZnS quantum dots with uniform size of 4.6 nm were firstly coated with a mesoporous silica to obtain a suitable intermediate transition layer, then an imprinted layer containing bifenthrin specific recognition sites was anchored. Characterizations verified the multilayer structure convincingly and the detection process relied on the electron transfer-induced fluorescence quenching mechanism. Optional detection time and standard detection curve were obtained within a concentration range from 5.0 to 50 μmol L -1 . The stability was verified to be good after 12 replicates. Feasibility of the probe was proved by monitoring water samples from the Zhenjiang reach of the Yangtze River. The probe offers promise for direct bifenthrin detection in unknown environmental water with an accurate and stable phosphorescence analysis strategy.

Prediction of fat-free body mass from bioelectrical impedance and anthropometry among 3-year-old children using DXA

PubMed Central

Ejlerskov, Katrine T.; Jensen, Signe M.; Christensen, Line B.; Ritz, Christian; Michaelsen, Kim F.; Mølgaard, Christian

2014-01-01

For 3-year-old children suitable methods to estimate body composition are sparse. We aimed to develop predictive equations for estimating fat-free mass (FFM) from bioelectrical impedance (BIA) and anthropometry using dual-energy X-ray absorptiometry (DXA) as reference method using data from 99 healthy 3-year-old Danish children. Predictive equations were derived from two multiple linear regression models, a comprehensive model (height2/resistance (RI), six anthropometric measurements) and a simple model (RI, height, weight). Their uncertainty was quantified by means of 10-fold cross-validation approach. Prediction error of FFM was 3.0% for both equations (root mean square error: 360 and 356 g, respectively). The derived equations produced BIA-based prediction of FFM and FM near DXA scan results. We suggest that the predictive equations can be applied in similar population samples aged 2–4 years. The derived equations may prove useful for studies linking body composition to early risk factors and early onset of obesity. PMID:24463487

Prediction of fat-free body mass from bioelectrical impedance and anthropometry among 3-year-old children using DXA.

PubMed

Ejlerskov, Katrine T; Jensen, Signe M; Christensen, Line B; Ritz, Christian; Michaelsen, Kim F; Mølgaard, Christian

2014-01-27

For 3-year-old children suitable methods to estimate body composition are sparse. We aimed to develop predictive equations for estimating fat-free mass (FFM) from bioelectrical impedance (BIA) and anthropometry using dual-energy X-ray absorptiometry (DXA) as reference method using data from 99 healthy 3-year-old Danish children. Predictive equations were derived from two multiple linear regression models, a comprehensive model (height(2)/resistance (RI), six anthropometric measurements) and a simple model (RI, height, weight). Their uncertainty was quantified by means of 10-fold cross-validation approach. Prediction error of FFM was 3.0% for both equations (root mean square error: 360 and 356 g, respectively). The derived equations produced BIA-based prediction of FFM and FM near DXA scan results. We suggest that the predictive equations can be applied in similar population samples aged 2-4 years. The derived equations may prove useful for studies linking body composition to early risk factors and early onset of obesity.

Solid dispersion of efavirenz in PVP K-30 by conventional solvent and kneading methods.

PubMed

Alves, Lariza Darlene Santos; de La Roca Soares, Mônica Felts; de Albuquerque, Camila Tavares; da Silva, Elica Rodrigues; Vieira, Alexandre Couto Carneiro; Fontes, Danilo Augusto Ferreira; Figueirêdo, Camila Bezerra Melo; Soares Sobrinho, José Lamartine; Rolim Neto, Pedro José

2014-04-15

Efavirenz (EFV) used as a part of the treatment of first choice in antiretroviral therapy for AIDS has low aqueous solubility and presents problems of absorption. We thus initially present a phase solubility diagram with carriers of different classes. With a view to obtaining a solid dispersion (SD) with suitable consistency to that of a solid formulation, we chose to use PVP K-30, since polymers present some of the best results. The kneading (KN) and solvent evaporation (EV) methods were thus used at different rates. These were characterized by the way of DSC, FT-IR, SEM, DR-X and dissolution. SD EV proved unsatisfactory, resulting in a decreased dissolution rate, despite the amorphous state of the samples, while the SD KN 4:1 (EFV:polymer) and physical mixtures (PM) had a higher rate of dissolution. SD KN and PM 4:1 were also evaluated for stability after storage, with benefits being observed in relation to EFV. Copyright © 2014. Published by Elsevier Ltd.

Analysis of simplified heat transfer models for thermal property determination of nano-film by TDTR method

NASA Astrophysics Data System (ADS)

Wang, Xinwei; Chen, Zhe; Sun, Fangyuan; Zhang, Hang; Jiang, Yuyan; Tang, Dawei

2018-03-01

Heat transfer in nanostructures is of critical importance for a wide range of applications such as functional materials and thermal management of electronics. Time-domain thermoreflectance (TDTR) has been proved to be a reliable measurement technique for the thermal property determinations of nanoscale structures. However, it is difficult to determine more than three thermal properties at the same time. Heat transfer model simplifications can reduce the fitting variables and provide an alternative way for thermal property determination. In this paper, two simplified models are investigated and analyzed by the transform matrix method and simulations. TDTR measurements are performed on Al-SiO2-Si samples with different SiO2 thickness. Both theoretical and experimental results show that the simplified tri-layer model (STM) is reliable and suitable for thin film samples with a wide range of thickness. Furthermore, the STM can also extract the intrinsic thermal conductivity and interfacial thermal resistance from serial samples with different thickness.

Biogas desulfurization and biogas upgrading using a hybrid membrane system--modeling study.

PubMed

Makaruk, A; Miltner, M; Harasek, M

2013-01-01

Membrane gas permeation using glassy membranes proved to be a suitable method for biogas upgrading and natural gas substitute production on account of low energy consumption and high compactness. Glassy membranes are very effective in the separation of bulk carbon dioxide and water from a methane-containing stream. However, the content of hydrogen sulfide can be lowered only partially. This work employs process modeling based upon the finite difference method to evaluate a hybrid membrane system built of a combination of rubbery and glassy membranes. The former are responsible for the separation of hydrogen sulfide and the latter separate carbon dioxide to produce standard-conform natural gas substitute. The evaluation focuses on the most critical upgrading parameters like achievable gas purity, methane recovery and specific energy consumption. The obtained results indicate that the evaluated hybrid membrane configuration is a potentially efficient system for the biogas processing tasks that do not require high methane recoveries, and allows effective desulfurization for medium and high hydrogen sulfide concentrations without additional process steps.

Assessing the habitat suitability of agricultural landscapes for characteristic breeding bird guilds using landscape metrics.

PubMed

Borges, Friederike; Glemnitz, Michael; Schultz, Alfred; Stachow, Ulrich

2017-04-01

Many of the processes behind the decline of farmland birds can be related to modifications in landscape structure (composition and configuration), which can partly be expressed quantitatively with measurable or computable indices, i.e. landscape metrics. This paper aims to identify statistical relationships between the occurrence of birds and the landscape structure. We present a method that combines two comprehensive procedures: the "landscape-centred approach" and "guild classification". Our study is based on more than 20,000 individual bird observations based on a 4-year bird monitoring approach in a typical agricultural area in the north-eastern German lowlands. Five characteristic bird guilds, each with three characteristic species, are defined for the typical habitat types of that area: farmland, grassland, hedgerow, forest and settlement. The suitability of each sample plot for each guild is indicated by the level of persistence (LOP) of occurrence of three respective species. Thus, the sample plots can be classified as "preferred" or "less preferred" depending on the lower and upper quartiles of the LOP values. The landscape structure is characterized by 16 different landscape metrics expressing various aspects of landscape composition and configuration. For each guild, the three landscape metrics with the strongest rank correlation with the LOP values and that are not mutually dependent were identified. For four of the bird guilds, the classification success was better than 80%, compared with only 66% for the grassland bird guild. A subset of six landscape metrics proved to be the most meaningful and sufficiently classified the sample areas with respect to bird guild suitability. In addition, derived logistic functions allowed the production of guild-specific habitat suitability maps for the whole landscape. The analytical results show that the proposed approach is appropriate to assess the habitat suitability of agricultural landscapes for characteristic bird guilds.

Test methods for estimating the efficacy of the fast-acting disinfectant peracetic acid on surfaces of personal protective equipment.

PubMed

Lemmer, K; Howaldt, S; Heinrich, R; Roder, A; Pauli, G; Dorner, B G; Pauly, D; Mielke, M; Schwebke, I; Grunow, R

2017-11-01

The work aimed at developing and evaluating practically relevant methods for testing of disinfectants on contaminated personal protective equipment (PPE). Carriers were prepared from PPE fabrics and contaminated with Bacillus subtilis spores. Peracetic acid (PAA) was applied as a suitable disinfectant. In method 1, the contaminated carrier was submerged in PAA solution; in method 2, the contaminated area was covered with PAA; and in method 3, PAA, preferentially combined with a surfactant, was dispersed as a thin layer. In each method, 0·5-1% PAA reduced the viability of spores by a factor of ≥6 log 10 within 3 min. The technique of the most realistic method 3 proved to be effective at low temperatures and also with a high organic load. Vaccinia virus and Adenovirus were inactivated with 0·05-0·1% PAA by up to ≥6 log 10 within 1 min. The cytotoxicity of ricin was considerably reduced by 2% PAA within 15 min of exposure. PAA/detergent mixture enabled to cover hydrophobic PPE surfaces with a thin and yet effective disinfectant layer. The test methods are objective tools for estimating the biocidal efficacy of disinfectants on hydrophobic flexible surfaces. © 2017 The Society for Applied Microbiology.

A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

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

Han, Hui; Peng, Ji-Run, E-mail: pengjr@medmail.com.cn; Chen, Peng-Cheng

Highlights: {yields} Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. {yields} An ideal artificial APCs system was successfully prepared in vivo. {yields} Controlled release of IL-2 leads to much more T-cell expansion. {yields} This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparationmore » of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.« less

Non-imaging ray-tracing for sputtering simulation with apodization

NASA Astrophysics Data System (ADS)

Ou, Chung-Jen

2018-04-01

Although apodization patterns have been adopted for the analysis of sputtering sources, the analytical solutions for the film thickness equations are yet limited to only simple conditions. Empirical formulations for thin film sputtering lacking the flexibility in dealing with multi-substrate conditions, a suitable cost-effective procedure is required to estimate the film thickness distribution. This study reports a cross-discipline simulation program, which is based on discrete particle Monte-Carlo methods and has been successfully applied to a non-imaging design to solve problems associated with sputtering uniformity. Robustness of the present method is first proved by comparing it with a typical analytical solution. Further, this report also investigates the overall all effects cause by the sizes of the deposited substrate, such that the determination of the distance between the target surface and the apodization index can be complete. This verifies the capability of the proposed method for solving the sputtering film thickness problems. The benefit is that an optical thin film engineer can, using the same optical software, design a specific optical component and consider the possible coating qualities with thickness tolerance, during the design stage.

[Simultaneous determination of 7 arsenic species in chicken muscle and chicken liver with high performance liquid chromatography-inductively coupled plasma mass spectrometry].

PubMed

Yang, Lijun; Hu, Qiaoru; Guo, Wei; Liu, Yumin; Song, Xiaohua; Zhang, Pengcheng

2011-05-01

A method for the simultaneous determination of 7 arsenic species was developed with high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The sample was extracted with artificial gastric juice. The HPLC separation was performed on an anion analytical column utilizing a gradient elution program of ammonium carbonate and water as the mobile phase. Identification and quantification were achieved by ICP-MS. Good linearities of 7 arsenic species were observed in the range from 1 microg/kg to 50 microg/kg with the correlation coefficients greater than 0.999. The average recoveries of 7 arsenic species spiked at the three levels of 1, 2 and 10 microg/kg ranged from 84.3% to 106.6% with the relative standard deviations of 1.4%-4.2%. The quantification limits of 7 arsenic species were 1 microg/kg. The method was proved to be good reproducibility, high sensitivity and simple preprocessing. This method is suitable for the simultaneous determination of 7 arsenic species in chicken muscle and chicken liver.

Non-imaging ray-tracing for sputtering simulation with apodization

NASA Astrophysics Data System (ADS)

Ou, Chung-Jen

2018-06-01

Although apodization patterns have been adopted for the analysis of sputtering sources, the analytical solutions for the film thickness equations are yet limited to only simple conditions. Empirical formulations for thin film sputtering lacking the flexibility in dealing with multi-substrate conditions, a suitable cost-effective procedure is required to estimate the film thickness distribution. This study reports a cross-discipline simulation program, which is based on discrete particle Monte-Carlo methods and has been successfully applied to a non-imaging design to solve problems associated with sputtering uniformity. Robustness of the present method is first proved by comparing it with a typical analytical solution. Further, this report also investigates the overall all effects cause by the sizes of the deposited substrate, such that the determination of the distance between the target surface and the apodization index can be complete. This verifies the capability of the proposed method for solving the sputtering film thickness problems. The benefit is that an optical thin film engineer can, using the same optical software, design a specific optical component and consider the possible coating qualities with thickness tolerance, during the design stage.

Synthesis and application of magnetite dextran-spermine nanoparticles in breast cancer hyperthermia.

PubMed

Avazzadeh, Reza; Vasheghani-Farahani, Ebrahim; Soleimani, Masoud; Amanpour, Saeid; Sadeghi, Mohsen

2017-09-01

Cancer treatment has been very challenging in recent decades. One of the most promising cancer treatment methods is hyperthermia, which increases the tumor temperature (41-45 °C). Magnetic nanoparticles have been widely used for selective targeting of cancer cells. In the present study, magnetic dextran-spermine nanoparticles, conjugated with Anti-HER2 antibody to target breast cancer cells were developed. The magnetic dextran-spermine nanoparticles (DMNPs) were prepared by ionic gelation, followed by conjugation of antibody to them using EDC-NHS method. Then the Prussian blue method was used to estimate the targeting ability and cellular uptake. Cytotoxicity assay by MTT showed that antibody-conjugated MNPs (ADMNPs) have no toxic effect on SKBR3 and human fibroblast cells. Finally, the hyperthermia was applied to show that synthesized ADMNPs, could increase the cancer cells temperature up to 45 °C and kill most of them without affecting normal cells. These observations proved that Anti-HER2 conjugated magnetic dextran-spermine nanoparticles can target and destroy cancer cells and are potentially suitable for cancer treatment.

Application of alternative fixatives to formalin in diagnostic pathology

PubMed Central

Gatta, L. Benerini; Cadei, M.; Balzarini, P.; Castriciano, S.; Paroni, R.; Verzeletti, A.; Cortellini, V.; De Ferrari, F.; Grigolato, P.

2012-01-01

Fixation is a critical step in the preparation of tissues for histopathology. The aim of this study was to investigate the effects of different fixatives vs formalin on proteins and DNA, and to evaluate alternative fixation for morphological diagnosis and nucleic acid preservation for molecular methods. Forty tissues were fixed for 24 h with six different fixatives: the gold standard fixative formalin, the historical fixatives Bouin and Hollande, and the alternative fixatives Greenfix, UPM and CyMol. Tissues were stained (Haematoxylin-Eosin, Periodic Acid Schiff, Trichromic, Alcian-blue, High Iron Diamine stainings), and their antigenicity was determined by immunohistochemistry (performed with PAN-CK, CD31, Ki-67, S100, CD68, AML antibodies). DNA extraction, KRAS sequencing, FISH for CEP-17, and flow cytometry analysis of nuclear DNA content were applied. For cell morphology the alternative fixatives (Greenfix, UPM, CyMol) were equivalent to formalin. As expected, Hollande proved to be the best fixative for morphology. The morphology obtained with Bouin was comparable to the one with formalin. Hollande was the best fixative for histochemistry. Bouin proved to be equivalent to formalin. The alternative fixatives were equivalent to formalin, although with greater variability in haematoxylin-eosin staining. It proved the possibility to obtain immunohistochemical staining largely equivalent to that following formalin-fixation with the following fixatives: Greenfix, Hollande, UPM and CyMol. The tissues fixed in Bouin did not provide results comparable to those obtained with formalin. The DNA extracted from samples fixed with alternative fixatives was found to be suitable for molecular analysis. PMID:22688293

Bird population and habitat surveys in urban areas

Treesearch

Richard M. DeGraaf; Aelred D. Geis; Patricia A. Healy

1991-01-01

Breeding bird populations in six habitats in Columbia. MD. were studied to develop procedures suitable for measuring bird use of residential areas and to identify habitat characteristics that define the distribution of various common bird species. A procedure to measure bird use based on 4-min transect counts on plots measuring 91 m × 91 m proved better than point...

IBX-mediated oxidation of unactivated cyclic amines: application in highly diastereoselective oxidative Ugi-type and aza-Friedel-Crafts reactions.

PubMed

de Graaff, C; Bensch, L; van Lint, Matthijs J; Ruijter, E; Orru, R V A

2015-10-28

The first o-iodoxybenzoic acid (IBX) mediated oxidation of unactivated amines to imines is described. A range of meso-pyrrolidines were shown to be suitable substrates. The chemical space was further explored with one-pot oxidative Ugi-type and aza-Friedel-Crafts reactions, which proved to be highly diastereoselective.

On the Well-Definedness of the Order of an Ordinary Differential Equation

ERIC Educational Resources Information Center

Dobbs, David E.

2006-01-01

It is proved that if the differential equations "y[(n)] = f(x,y,y[prime],...,y[(n-1)])" and "y[(m)] = g(x,y,y[prime],...,y[(m-1)])" have the same particular solutions in a suitable region where "f" and "g" are continuous real-valued functions with continuous partial derivatives (alternatively, continuous functions satisfying the classical…

Fuzzy controller training using particle swarm optimization for nonlinear system control.

PubMed

Karakuzu, Cihan

2008-04-01

This paper proposes and describes an effective utilization of particle swarm optimization (PSO) to train a Takagi-Sugeno (TS)-type fuzzy controller. Performance evaluation of the proposed fuzzy training method using the obtained simulation results is provided with two samples of highly nonlinear systems: a continuous stirred tank reactor (CSTR) and a Van der Pol (VDP) oscillator. The superiority of the proposed learning technique is that there is no need for a partial derivative with respect to the parameter for learning. This fuzzy learning technique is suitable for real-time implementation, especially if the system model is unknown and a supervised training cannot be run. In this study, all parameters of the controller are optimized with PSO in order to prove that a fuzzy controller trained by PSO exhibits a good control performance.

Hardware Neural Network for a Visual Inspection System

NASA Astrophysics Data System (ADS)

Chun, Seungwoo; Hayakawa, Yoshihiro; Nakajima, Koji

The visual inspection of defects in products is heavily dependent on human experience and instinct. In this situation, it is difficult to reduce the production costs and to shorten the inspection time and hence the total process time. Consequently people involved in this area desire an automatic inspection system. In this paper, we propose a hardware neural network, which is expected to provide high-speed operation for automatic inspection of products. Since neural networks can learn, this is a suitable method for self-adjustment of criteria for classification. To achieve high-speed operation, we use parallel and pipelining techniques. Furthermore, we use a piecewise linear function instead of a conventional activation function in order to save hardware resources. Consequently, our proposed hardware neural network achieved 6GCPS and 2GCUPS, which in our test sample proved to be sufficiently fast.

Global stability and pattern formation in a nonlocal diffusive Lotka-Volterra competition model

NASA Astrophysics Data System (ADS)

Ni, Wenjie; Shi, Junping; Wang, Mingxin

2018-06-01

A diffusive Lotka-Volterra competition model with nonlocal intraspecific and interspecific competition between species is formulated and analyzed. The nonlocal competition strength is assumed to be determined by a diffusion kernel function to model the movement pattern of the biological species. It is shown that when there is no nonlocal intraspecific competition, the dynamics properties of nonlocal diffusive competition problem are similar to those of classical diffusive Lotka-Volterra competition model regardless of the strength of nonlocal interspecific competition. Global stability of nonnegative constant equilibria are proved using Lyapunov or upper-lower solution methods. On the other hand, strong nonlocal intraspecific competition increases the system spatiotemporal dynamic complexity. For the weak competition case, the nonlocal diffusive competition model may possess nonconstant positive equilibria for some suitably large nonlocal intraspecific competition coefficients.

Resin adhesion strengths to zirconia ceramics after primer treatment with silane coupling monomer or oligomer.

PubMed

Okada, Masahiro; Inoue, Kazusa; Irie, Masao; Taketa, Hiroaki; Torii, Yasuhiro; Matsumoto, Takuya

2017-09-26

Resin bonding to zirconia ceramics is difficult to achieve using the standard methods for conventional silica-based dental ceramics, which employ silane coupling monomers as primers. The hypothesis in this study was that a silane coupling oligomer -a condensed product of silane coupling monomers- would be a more suitable primer for zirconia. To prove this hypothesis, the shear bond strengths between a composite resin and zirconia were compared after applying either a silane coupling monomer or oligomer. The shear bond strength increased after applying a non-activated ethanol solution of the silane coupling oligomer compared with that achieved when applying the monomer. Thermal treatment of the zirconia at 110°C after application of the silane coupling agents was essential to improve the shear bond strength between the composite resin cement and zirconia.

Elemental Levels Analyzed by PIXE in Florida Alligators

NASA Astrophysics Data System (ADS)

Kuharik, J. C.; Kravchenko, I. I.; Dunnam, F. E.; Van Rinsvelt, H. A.; Ross, J. P.

2003-08-01

Unusual and alarming mortality of alligators (Alligator mississippiensis) has been reported from Lake Griffin, Florida, where almost 400 dead alligators have been observed since 1997. In addition, the hatch rate for alligator eggs around Lake Griffin fell below 10% and remains low (30-45%) while the normal hatch rate is typically 80%. Standard diagnostic methods have been ineffective in determining the cause of the phenomenon. Many possibilities have been considered including pollutants, nutrition, and toxic algae. Particle Induced X-ray Emission (PIXE) analysis is highly suitable for investigating concentrations of a wide range of elements in animal tissue. Liver, kidney and spinal cord tissues from healthy and sick alligators have been analyzed by PIXE for elemental content. Initial results showed positive correlation between certain elements and neural impairment and morbidity of alligators in Lake Griffin, but have failed to prove significant.

10 CFR 963.16 - Postclosure suitability evaluation method.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Postclosure suitability evaluation method. 963.16 Section... Determination, Methods, and Criteria § 963.16 Postclosure suitability evaluation method. (a) DOE will evaluate postclosure suitability using the total system performance assessment method. DOE will conduct a total system...

10 CFR 963.16 - Postclosure suitability evaluation method.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Postclosure suitability evaluation method. 963.16 Section... Determination, Methods, and Criteria § 963.16 Postclosure suitability evaluation method. (a) DOE will evaluate postclosure suitability using the total system performance assessment method. DOE will conduct a total system...

10 CFR 963.16 - Postclosure suitability evaluation method.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Postclosure suitability evaluation method. 963.16 Section... Determination, Methods, and Criteria § 963.16 Postclosure suitability evaluation method. (a) DOE will evaluate postclosure suitability using the total system performance assessment method. DOE will conduct a total system...

Polyethylene Naphthalate Scintillator: A Novel Detector for the Dosimetry of Radioactive Ophthalmic Applicators

PubMed Central

Flühs, Dirk; Flühs, Andrea; Ebenau, Melanie; Eichmann, Marion

2015-01-01

Background Dosimetric measurements in small radiation fields with large gradients, such as eye plaque dosimetry with β or low-energy photon emitters, require dosimetrically almost water-equivalent detectors with volumes of <1 mm3 and linear responses over several orders of magnitude. Polyvinyltoluene-based scintillators fulfil these conditions. Hence, they are a standard for such applications. However, they show disadvantages with regard to certain material properties and their dosimetric behaviour towards low-energy photons. Purpose, Materials and Methods Polyethylene naphthalate, recently recognized as a scintillator, offers chemical, physical and basic dosimetric properties superior to polyvinyltoluene. Its general applicability as a clinical dosimeter, however, has not been shown yet. To prove this applicability, extensive measurements at several clinical photon and electron radiation sources, ranging from ophthalmic plaques to a linear accelerator, were performed. Results For all radiation qualities under investigation, covering a wide range of dose rates, a linearity of the detector response to the dose was shown. Conclusion Polyethylene naphthalate proved to be a suitable detector material for the dosimetry of ophthalmic plaques, including low-energy photon emitters and other small radiation fields. Due to superior properties, it has the potential to replace polyvinyltoluene as the standard scintillator for such applications. PMID:27171681

Comparative in vitro activity of tigecycline against bacteria recovered from clinical specimens in Latin America.

PubMed

Bantar, C; Curcio, D; Fernandez Canigia, L; García, P; Guzmán Blanco, M; Leal, A L

2009-04-01

The present study was performed to evaluate the in vitro activity of tigecycline in comparison to other agents against isolates recovered from patients hospitalized in latin American. Organisms were collected in 47 clinical laboratories from 4 countries of latin America between November 2005 and October 2006 and were tested by using disk diffusion method as described by the CLSI. A total of 7966 isolates were assessed. Tigecycline proved highly active against staphylococci and enterococci (>99% susceptibility). Imipenem was the most active agent against Escherichia coli (100% susceptibility), followed by tigecycline, 98.6% susceptibility. Resistance to cefotaxime in this species was 15.3%. Global tigecycline susceptibility of Klebsiella species was 90.2%, but the susceptibility rate was significantly slower in Venezuela (82%) than in Argentina, Colombia and Chile (93%) (p<0.01). Global cefotaxime resistance to Klebsiella spp. was 32.2% and carbapenem resistance was detected in all countries. By adopting a susceptible breakpoint >or =16mm, 91.3% of the Acinetobacter isolates proved susceptible to tigecycline. Results from the present study suggest that tigecycline may be a suitable option in latin America, a region where multidrug resistance seems to be a dramatic, increasing problem and new antimicrobial choices are urgently needed.

Development of the Improving Process for the 3D Printed Structure

NASA Astrophysics Data System (ADS)

Takagishi, Kensuke; Umezu, Shinjiro

2017-01-01

The authors focus on the Fused Deposition Modeling (FDM) 3D printer because the FDM 3D printer can print the utility resin material. It can print with low cost and therefore it is the most suitable for home 3D printer. The FDM 3D printer has the problem that it produces layer grooves on the surface of the 3D printed structure. Therefore the authors developed the 3D-Chemical Melting Finishing (3D-CMF) for removing layer grooves. In this method, a pen-style device is filled with a chemical able to dissolve the materials used for building 3D printed structures. By controlling the behavior of this pen-style device, the convex parts of layer grooves on the surface of the 3D printed structure are dissolved, which, in turn, fills the concave parts. In this study it proves the superiority of the 3D-CMF than conventional processing for the 3D printed structure. It proves utilizing the evaluation of the safety, selectively and stability. It confirms the improving of the 3D-CMF and it is confirmed utilizing the data of the surface roughness precision and the observation of the internal state and the evaluation of the mechanical characteristics.

Development of the Improving Process for the 3D Printed Structure

PubMed Central

Takagishi, Kensuke; Umezu, Shinjiro

2017-01-01

The authors focus on the Fused Deposition Modeling (FDM) 3D printer because the FDM 3D printer can print the utility resin material. It can print with low cost and therefore it is the most suitable for home 3D printer. The FDM 3D printer has the problem that it produces layer grooves on the surface of the 3D printed structure. Therefore the authors developed the 3D-Chemical Melting Finishing (3D-CMF) for removing layer grooves. In this method, a pen-style device is filled with a chemical able to dissolve the materials used for building 3D printed structures. By controlling the behavior of this pen-style device, the convex parts of layer grooves on the surface of the 3D printed structure are dissolved, which, in turn, fills the concave parts. In this study it proves the superiority of the 3D-CMF than conventional processing for the 3D printed structure. It proves utilizing the evaluation of the safety, selectively and stability. It confirms the improving of the 3D-CMF and it is confirmed utilizing the data of the surface roughness precision and the observation of the internal state and the evaluation of the mechanical characteristics. PMID:28054558

Development of the Improving Process for the 3D Printed Structure.

PubMed

Takagishi, Kensuke; Umezu, Shinjiro

2017-01-05

The authors focus on the Fused Deposition Modeling (FDM) 3D printer because the FDM 3D printer can print the utility resin material. It can print with low cost and therefore it is the most suitable for home 3D printer. The FDM 3D printer has the problem that it produces layer grooves on the surface of the 3D printed structure. Therefore the authors developed the 3D-Chemical Melting Finishing (3D-CMF) for removing layer grooves. In this method, a pen-style device is filled with a chemical able to dissolve the materials used for building 3D printed structures. By controlling the behavior of this pen-style device, the convex parts of layer grooves on the surface of the 3D printed structure are dissolved, which, in turn, fills the concave parts. In this study it proves the superiority of the 3D-CMF than conventional processing for the 3D printed structure. It proves utilizing the evaluation of the safety, selectively and stability. It confirms the improving of the 3D-CMF and it is confirmed utilizing the data of the surface roughness precision and the observation of the internal state and the evaluation of the mechanical characteristics.

The suitability of the simplified method of the analysis of coffee infusions on the content of Ca, Cu, Fe, Mg, Mn and Zn and the study of the effect of preparation conditions on the leachability of elements into the coffee brew.

PubMed

Stelmach, Ewelina; Pohl, Pawel; Szymczycha-Madeja, Anna

2013-12-01

A fast and straightforward method of the analysis of coffee infusions was developed for measurements of total concentrations of Ca, Cu, Fe, Mg, Mn and Zn by flame atomic absorption spectrometry. Its validity was proved by the analysis of spiked samples; recoveries of added metals were found to be within 98-104% while the precision was better than 4%. The method devised was used for the analysis of re-distilled water infusions of six popular ground coffees available in the Polish market. Using the mud coffee preparation it was established that percentages of metals leached in these conditions varied a lot among analysed coffees, especially for Ca (14-42%), Mg (6-25%) and Zn (1-24%). For remaining metals, the highest extractabilities were assessed for Mn (30-52%) while the lowest for Fe (4-16%) and Cu (2-12%). In addition, it was found that the water type and the coffee brewing preparation method influence the concentration of studied metals in coffee infusions the most. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hybrid state vector methods for structural dynamic and aeroelastic boundary value problems

NASA Technical Reports Server (NTRS)

Lehman, L. L.

1982-01-01

A computational technique is developed that is suitable for performing preliminary design aeroelastic and structural dynamic analyses of large aspect ratio lifting surfaces. The method proves to be quite general and can be adapted to solving various two point boundary value problems. The solution method, which is applicable to both fixed and rotating wing configurations, is based upon a formulation of the structural equilibrium equations in terms of a hybrid state vector containing generalized force and displacement variables. A mixed variational formulation is presented that conveniently yields a useful form for these state vector differential equations. Solutions to these equations are obtained by employing an integrating matrix method. The application of an integrating matrix provides a discretization of the differential equations that only requires solutions of standard linear matrix systems. It is demonstrated that matrix partitioning can be used to reduce the order of the required solutions. Results are presented for several example problems in structural dynamics and aeroelasticity to verify the technique and to demonstrate its use. These problems examine various types of loading and boundary conditions and include aeroelastic analyses of lifting surfaces constructed from anisotropic composite materials.

Bridging the gap between formal and experience-based knowledge for context-aware laparoscopy.

PubMed

Katić, Darko; Schuck, Jürgen; Wekerle, Anna-Laura; Kenngott, Hannes; Müller-Stich, Beat Peter; Dillmann, Rüdiger; Speidel, Stefanie

2016-06-01

Computer assistance is increasingly common in surgery. However, the amount of information is bound to overload processing abilities of surgeons. We propose methods to recognize the current phase of a surgery for context-aware information filtering. The purpose is to select the most suitable subset of information for surgical situations which require special assistance. We combine formal knowledge, represented by an ontology, and experience-based knowledge, represented by training samples, to recognize phases. For this purpose, we have developed two different methods. Firstly, we use formal knowledge about possible phase transitions to create a composition of random forests. Secondly, we propose a method based on cultural optimization to infer formal rules from experience to recognize phases. The proposed methods are compared with a purely formal knowledge-based approach using rules and a purely experience-based one using regular random forests. The comparative evaluation on laparoscopic pancreas resections and adrenalectomies employs a consistent set of quality criteria on clean and noisy input. The rule-based approaches proved best with noisefree data. The random forest-based ones were more robust in the presence of noise. Formal and experience-based knowledge can be successfully combined for robust phase recognition.

A novel method to fabricate silicon tubular gratings with broadband antireflection and super-hydrophobicity.

PubMed

Gao, Yang; Shi, Tielin; Tan, Xianhua; Liao, Guanglan

2014-06-01

We have developed a novel method to fabricate micro/nano structure based on the coherent diffraction lithography, and acquired periodic silicon tubular gratings with deep nano-scale tapered profiles at the top part. The optical properties of these tubular gratings were similar to an effective gradient-index antireflective surface, resulting in a broadband antireflective combining super-hydrophobic behavior. The mechanism of the method was simulated by rigorous coupled wave analysis algorithms. Then coherent diffraction lithography by use of suitable mask, in which periodic micro-scale circular opaque patters were distributed, was realized on the traditional aligner. Due to coherent diffraction, we obtained enough light intensity for photoresist exposure under the center of the opaque area in the mask together with transparent areas. The tapered line profiles and hollow photoresist gratings over large areas could be fabricated on the silicon wafer after development. The dry etching process was carried out, and high aspect ratio silicon tubular gratings with deep tapered profiles at the top were fabricated. The optical property and wettability of the structure were verified, proving that the proposed method and obtained micro/nano structure provide application potential in the future.

Intra-abdominal fat: Comparison of computed tomography fat segmentation and bioimpedance spectroscopy.

PubMed

Finch, Peter

2017-06-01

Intra-abdominal fat is an important factor in determining the metabolic syndrome/insulin resistance, and thus the risk of diabetes and ischaemic heart disease. Computed Tomography (CT) fat segmentation represents a defined method of quantifying intra-abdominal fat, with attendant radiation risks. Bioimpedance spectroscopy may offer a method of assessment without any risks to the patients. A comparison is made of these two methods. This was a preliminary study of the utility of multifrequency bioimpedance spectroscopy of the mid abdomen as a measure of intra-abdominal fat, by comparison with fat segmentation of an abdominal CT scan in the -30 to -190 HU range. There was a significant (P < 0.01) correlation between intra-abdominal fat and mid-upper arm circumference, as well as the bioimpedance parameter, the R/S ratio. Multivariate analysis showed that these were the only independant variables and allowed the derivation of a formula to estimate intra-abdominal fat: IAF = 0.02 × MAC - 0.757 × R/S + 0.036. Circumabdominal bioimpedance spectroscopy may prove a useful method of assessing intra-abdominal fat, and may be suitable for use in studies to enhance other measures of body composition, such as mid-upper arm circumference.

Damage detection in composite materials using Lamb wave methods

NASA Astrophysics Data System (ADS)

Kessler, Seth S.; Spearing, S. Mark; Soutis, Constantinos

2002-04-01

Cost-effective and reliable damage detection is critical for the utilization of composite materials. This paper presents part of an experimental and analytical survey of candidate methods for in situ damage detection of composite materials. Experimental results are presented for the application of Lamb wave techniques to quasi-isotropic graphite/epoxy test specimens containing representative damage modes, including delamination, transverse ply cracks and through-holes. Linear wave scans were performed on narrow laminated specimens and sandwich beams with various cores by monitoring the transmitted waves with piezoceramic sensors. Optimal actuator and sensor configurations were devised through experimentation, and various types of driving signal were explored. These experiments provided a procedure capable of easily and accurately determining the time of flight of a Lamb wave pulse between an actuator and sensor. Lamb wave techniques provide more information about damage presence and severity than previously tested methods (frequency response techniques), and provide the possibility of determining damage location due to their local response nature. These methods may prove suitable for structural health monitoring applications since they travel long distances and can be applied with conformable piezoelectric actuators and sensors that require little power.

Evaluation method on steering for the shape-shifting robot in different configurations

NASA Astrophysics Data System (ADS)

Chang, Jian; Li, Bin; Wang, Chong; Zheng, Huaibing; Li, Zhiqiang

2016-01-01

The evaluation method on steering is based on qualitative manner in existence, which causes the result inaccurate and fuzziness. It reduces the efficiency of process execution. So the method by quantitative manner for the shape-shifting robot in different configurations is proposed. Comparing to traditional evaluation method, the most important aspects which can influence the steering abilities of the robot in different configurations are researched in detail, including the energy, angular velocity, time and space. In order to improve the robustness of system, the ideal and slippage conditions are all considered by mathematical model. Comparing to the traditional weighting confirming method, the extent of robot steering method is proposed by the combination of subjective and objective weighting method. The subjective weighting method can show more preferences of the experts and is based on five-grade scale. The objective weighting method is based on information entropy to determine the factors. By the sensors fixed on the robot, the contract force between track grouser and ground, the intrinsic motion characteristics of robot are obtained and the experiment is done to prove the algorithm which is proposed as the robot in different common configurations. Through the method proposed in the article, fuzziness and inaccurate of the evaluation method has been solved, so the operators can choose the most suitable configuration of the robot to fulfil the different tasks more quickly and simply.

Stability-indicating UPLC method for determination of Valsartan and their degradation products in active pharmaceutical ingredient and pharmaceutical dosage forms.

PubMed

Krishnaiah, Ch; Reddy, A Raghupathi; Kumar, Ramesh; Mukkanti, K

2010-11-02

A simple, precise, accurate stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the quantitative determination of purity of Valsartan drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. The method was developed using Waters Aquity BEH C18 (100 mm x 2.1 mm, 1.7 microm) column with mobile phase containing a gradient mixture of solvents A and B. The eluted compounds were monitored at 225 nm, the run time was within 9.5 min, which Valsartan and its seven impurities were well separated. Valsartan was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Valsartan was found to degrade significantly in acid and oxidative stress conditions and stable in base, hydrolytic and photolytic degradation conditions. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per international conference on harmonization (ICH) guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of Valsartan in pharmaceutical dosage forms.

Validation and Uncertainty Estimation of an Ecofriendly and Stability-Indicating HPLC Method for Determination of Diltiazem in Pharmaceutical Preparations

PubMed Central

Sadeghi, Fahimeh; Navidpour, Latifeh; Bayat, Sima; Afshar, Minoo

2013-01-01

A green, simple, and stability-indicating RP-HPLC method was developed for the determination of diltiazem in topical preparations. The separation was based on a C18 analytical column using a mobile phase consisted of ethanol: phosphoric acid solution (pH = 2.5) (35 : 65, v/v). Column temperature was set at 50°C and quantitation was achieved with UV detection at 240 nm. In forced degradation studies, the drug was subjected to oxidation, hydrolysis, photolysis, and heat. The method was validated for specificity, selectivity, linearity, precision, accuracy, and robustness. The applied procedure was found to be linear in diltiazem concentration range of 0.5–50 μg/mL (r 2 = 0.9996). Precision was evaluated by replicate analysis in which % relative standard deviation (RSD) values for areas were found below 2.0. The recoveries obtained (99.25%–101.66%) ensured the accuracy of the developed method. The degradation products as well as the pharmaceutical excipients were well resolved from the pure drug. The expanded uncertainty (5.63%) of the method was also estimated from method validation data. Accordingly, the proposed validated and sustainable procedure was proved to be suitable for routine analyzing and stability studies of diltiazem in pharmaceutical preparations. PMID:24163778

Well-posedness for a class of doubly nonlinear stochastic PDEs of divergence type

NASA Astrophysics Data System (ADS)

Scarpa, Luca

2017-08-01

We prove well-posedness for doubly nonlinear parabolic stochastic partial differential equations of the form dXt - div γ (∇Xt) dt + β (Xt) dt ∋ B (t ,Xt) dWt, where γ and β are the two nonlinearities, assumed to be multivalued maximal monotone operators everywhere defined on Rd and R respectively, and W is a cylindrical Wiener process. Using variational techniques, suitable uniform estimates (both pathwise and in expectation) and some compactness results, well-posedness is proved under the classical Leray-Lions conditions on γ and with no restrictive smoothness or growth assumptions on β. The operator B is assumed to be Hilbert-Schmidt and to satisfy some classical Lipschitz conditions in the second variable.

Green synthesis of anisotropic gold nanoparticles for photothermal therapy of cancer.

PubMed

Fazal, Sajid; Jayasree, Aswathy; Sasidharan, Sisini; Koyakutty, Manzoor; Nair, Shantikumar V; Menon, Deepthy

2014-06-11

Nanoparticles of varying composition, size, shape, and architecture have been explored for use as photothermal agents in the field of cancer nanomedicine. Among them, gold nanoparticles provide a simple platform for thermal ablation owing to its biocompatibility in vivo. However, the synthesis of such gold nanoparticles exhibiting suitable properties for photothermal activity involves cumbersome routes using toxic chemicals as capping agents, which can cause concerns in vivo. Herein, gold nanoparticles, synthesized using green chemistry routes possessing near-infrared (NIR) absorbance facilitating photothermal therapy, would be a viable alternative. In this study, anisotropic gold nanoparticles were synthesized using an aqueous route with cocoa extract which served both as a reducing and stabilizing agent. The as-prepared gold nanoparticles were subjected to density gradient centrifugation to maximize its NIR absorption in the wavelength range of 800-1000 nm. The particles also showed good biocompatibility when tested in vitro using A431, MDA-MB231, L929, and NIH-3T3 cell lines up to concentrations of 200 μg/mL. Cell death induced in epidermoid carcinoma A431 cells upon irradiation with a femtosecond laser at 800 nm at a low power density of 6 W/cm(2) proved the suitability of green synthesized NIR absorbing anisotropic gold nanoparticles for photothermal ablation of cancer cells. These gold nanoparticles also showed good X-ray contrast when tested using computed tomography (CT), proving their feasibility for use as a contrast agent as well. This is the first report on green synthesized anisotropic and cytocompatible gold nanoparticles without any capping agents and their suitability for photothermal therapy.

Validated green high-performance liquid chromatographic methods for the determination of coformulated pharmaceuticals: a comparison with reported conventional methods.

PubMed

Elzanfaly, Eman S; Hegazy, Maha A; Saad, Samah S; Salem, Maissa Y; Abd El Fattah, Laila E

2015-03-01

The introduction of sustainable development concepts to analytical laboratories has recently gained interest, however, most conventional high-performance liquid chromatography methods do not consider either the effect of the used chemicals or the amount of produced waste on the environment. The aim of this work was to prove that conventional methods can be replaced by greener ones with the same analytical parameters. The suggested methods were designed so that they neither use nor produce harmful chemicals and produce minimum waste to be used in routine analysis without harming the environment. This was achieved by using green mobile phases and short run times. Four mixtures were chosen as models for this study; clidinium bromide/chlordiazepoxide hydrochloride, phenobarbitone/pipenzolate bromide, mebeverine hydrochloride/sulpiride, and chlorphenoxamine hydrochloride/caffeine/8-chlorotheophylline either in their bulk powder or in their dosage forms. The methods were validated with respect to linearity, precision, accuracy, system suitability, and robustness. The developed methods were compared to the reported conventional high-performance liquid chromatography methods regarding their greenness profile. The suggested methods were found to be greener and more time- and solvent-saving than the reported ones; hence they can be used for routine analysis of the studied mixtures without harming the environment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toward decentralized analysis of mercury (II) in real samples. A critical review on nanotechnology-based methodologies.

PubMed

Botasini, Santiago; Heijo, Gonzalo; Méndez, Eduardo

2013-10-24

In recent years, it has increased the number of works focused on the development of novel nanoparticle-based sensors for mercury detection, mainly motivated by the need of low cost portable devices capable of giving fast and reliable analytical response, thus contributing to the analytical decentralization. Methodologies employing colorimetric, fluorometric, magnetic, and electrochemical output signals allowed reaching detection limits within the pM and nM ranges. Most of these developments proved their suitability in detecting and quantifying mercury (II) ions in synthetic solutions or spiked water samples. However, the state of art in these technologies is still behind the standard methods of mercury quantification, such as cold vapor atomic absorption spectrometry and inductively coupled plasma techniques, in terms of reliability and sensitivity. This is mainly because the response of nanoparticle-based sensors is highly affected by the sample matrix. The developed analytical nanosystems may fail in real samples because of the negative incidence of the ionic strength and the presence of exchangeable ligands. The aim of this review is to critically consider the recently published innovations in this area, and highlight the needs to include more realistic assays in future research in order to make these advances suitable for on-site analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

Cr(VI) and Cr(III) removal from aqueous solution by raw and modified lignocellulosic materials: a review.

PubMed

Miretzky, P; Cirelli, A Fernandez

2010-08-15

In aqueous systems, chromium usually exists in both trivalent and hexavalent oxidation states, being Cr(VI) of particular importance and concern due to its great toxicity. Industrial sources of Cr(VI) are leather tanning, mining of chrome ore, production of steel and alloys, etc. The most common conventional method for Cr(VI) removal is reduction to Cr(III) at pH 2.0 and precipitation of Cr (OH)(3) with lime at pH 9-10. The disadvantage of precipitation is the disposal of the solid waste. Adsorption of Cr by different low cost materials seems to be a suitable choice for wastewater treatment. Many by-products of agriculture have proved to be suitable low cost adsorbents for Cr(VI) and Cr(III) removal from water. Lignocellulosic residues, which include both wood residues and agricultural residues, have adsorption capacity comparable to other natural sorbents, but they have the advantage of very low or no cost, great availability and simple operational process. This study is a review of the recent literature on the use of natural and modified lignocellulosic residues for Cr adsorption. The Cr maximum adsorption capacity and the adsorption mechanism under different experimental conditions are reported when possibly. Copyright 2010 Elsevier B.V. All rights reserved.

High temperature ultrasonic transducers for imaging and measurements in a liquid Pb/Bi eutectic alloy.

PubMed

Kazys, Rymantas; Voleisis, Algirdas; Sliteris, Reimondas; Mazeika, Liudas; Van Nieuwenhove, Rudi; Kupschus, Peter; Abderrahim, Hamid Aït

2005-04-01

In some nuclear reactors or accelerator-driven systems (ADS) the core is intended to be cooled by means of a heavy liquid metal, for example, lead-bismuth (Pb/Bi) eutectic alloy. For safety and licensing reasons, an imaging method of the interior of ADS, based on application of ultrasonic waves, has thus to be developed. This paper is devoted to description of developed various ultrasonic transducers suitable for long term imaging and measurements in the liquid Pb/Bi alloy. The results of comparative experimental investigations of the developed transducers of different designs in a liquid Pb/Bi alloy up to 450 degrees C are presented. Prototypes with different high temperature piezoelectric materials were investigated: PZT, bismuth titanate (Bi4Ti3O12), lithium niobate (LiNbO3), gallium orthophosphate (GaPO4) and aluminum nitride (A1N). For acoustic coupling with the metal alloy, it was proposed to coat the active surface of the transducers by diamond like carbon (DLC). The radiation robustness was assessed by exposing the transducers to high gamma dose rates in one of the irradiation facilities at SCK x CEN. The experimental results proved that the developed transducers are suitable for long-term operation in harsh conditions.

A New Approach for Proving or Generating Combinatorial Identities

ERIC Educational Resources Information Center

Gonzalez, Luis

2010-01-01

A new method for proving, in an immediate way, many combinatorial identities is presented. The method is based on a simple recursive combinatorial formula involving n + 1 arbitrary real parameters. Moreover, this formula enables one not only to prove, but also generate many different combinatorial identities (not being required to know them "a…

YAlO3:Ce3+ powders: Synthesis, characterization, thermoluminescence and optical studies

NASA Astrophysics Data System (ADS)

Parganiha, Yogita; Kaur, Jagjeet; Dubey, Vikas; Shrivastava, Ravi

2015-09-01

Yttrium aluminum perovskite (YAP) is a promising high temperature ceramic material, known for its mechanical, structural and optical properties. YAP's also known as an ideal host material for solid-state lasers and phosphors. In this work, Ce3+ doped YAlO3 phosphors were synthesized by solid state reaction method, which is very suitable technique for large scale production. A prepared phosphor was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Photoluminescence spectra and Thermoluminescence (TL) glow curve study. The starting reagents used for sample preparation are Y2O3, Al2O3 and CeO2, boric acid used as a flux. Ratio of Y:Al was 1:1 which shows perovskite structure confirmed by the X-ray diffraction (XRD) study. The entire prepared sample was studied by PL excitation and emission spectra. Prominent peak at 446 nm (blue emission) which shows broad emission spectra of photoluminescence. It proves that prepared phosphor can act as a single host for blue emission of light and can be used for display applications. Commission Internationale de I'Eclairage (CIE) techniques proves the blue emission of light (x = .148, y = .117). TL glow curve analysis of prepared phosphor shows the prominent peak at 189 °C for the variable UV exposure time and high temperature peak shows the more stability and less fading in the prepared phosphor. Kinetic data of prepared phosphor were evaluated by peak shape method for variable UV exposure time (5-25 min).

Temporal segmentation of animal trajectories informed by habitat use

USGS Publications Warehouse

van Toor, Marielle L.; Newman, Scott H.; Takekawa, John Y.; Wegmann, Martin; Safi, Kamran

2016-01-01

Most animals live in seasonal environments and experience very different conditions throughout the year. Behavioral strategies like migration, hibernation, and a life cycle adapted to the local seasonality help to cope with fluctuations in environmental conditions. Thus, how an individual utilizes the environment depends both on the current availability of habitat and the behavioral prerequisites of the individual at that time. While the increasing availability and richness of animal movement data has facilitated the development of algorithms that classify behavior by movement geometry, changes in the environmental correlates of animal movement have so far not been exploited for a behavioral annotation. Here, we suggest a method that uses these changes in individual–environment associations to divide animal location data into segments of higher ecological coherence, which we term niche segmentation. We use time series of random forest models to evaluate the transferability of habitat use over time to cluster observational data accordingly. We show that our method is able to identify relevant changes in habitat use corresponding to both changes in the availability of habitat and how it was used using simulated data, and apply our method to a tracking data set of common teal (Anas crecca). The niche segmentation proved to be robust, and segmented habitat suitability outperformed models neglecting the temporal dynamics of habitat use. Overall, we show that it is possible to classify animal trajectories based on changes of habitat use similar to geometric segmentation algorithms. We conclude that such an environmentally informed classification of animal trajectories can provide new insights into an individuals' behavior and enables us to make sensible predictions of how suitable areas might be connected by movement in space and time.

An improved method for the analysis of 2-aminoacetophenone in wine based on headspace solid-phase microextraction and heart-cut multidimensional gas chromatography with selective detection by tandem mass spectrometry.

PubMed

Schmarr, Hans-Georg; Keiser, Jutta; Krautwald, Susann

2016-12-16

Heart-cut multidimensional gas chromatography coupled to selective mass spectrometric detection (H/C MDGC-MS-MS) was shown to be a suitable combination for analysis of the key component for the wine off-flavor named "atypical aging off-flavor" (german: "Untypische Alterungsnote", UTA), 2-aminoacetophenone (2-AAP). Headspace solid phase microextraction (HS-SPME) was applied as an easy to automate sample preparation step suiting routine control situations. During method development two critical aspects were found, of which one is the chemical degradation of the neat substance, leading to signal reduction and a false response behavior. A second aspect is the pH stability of the deuterated isotopologue 1-(2-aminophenyl)-2,2,2-trideuterio-ethanone (2-AAP-d3) used for quantification via a stable isotope dilution assay. Despite an earlier suggestion to increase the extractable amount of 2-AAP and its isotopic standard in the headspace, alkalization of 2-AAP-d3 containing aqueous samples were found to be critical. In such a milieu a deuterium exchange can then cause erroneous quantitative results. The method proposed in our study thus uses native wine pH conditions and proved to be suitable for routine control with respect to the detection of the "atypical aging off-flavor" in wine at concentration levels below its sensory threshold of about 1μgL -1 . Good linearity was obtained in the calibrated range from 0.1-8μgL -1 (y=1,2338x+0,1029, R=0,9985) with limits of detection or quantification being 0.01 and 0.14μg/L, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

[Implementing the Cross-Disciplinary Subject Palliative Care - Lecture's Perspective].

PubMed

Isermeyer, Leonie; Ilse, Benjamin; Marx, Gabriella; Seidemann, Stephanie; Jünger, Jana; Nauck, Friedemann; Alt-Epping, Bernd

2017-11-01

Introduction  In 2009, palliative care was introduced as a mandatory subject in the undergraduate medical curriculum in Germany. Despite all efforts to integrate this subject into the curriculum, research suggests substantial differences and deficits in the quality of education between the medical schools. The aim of this research was to find out promoting as well as impedimental aspects of implementing palliative care in the medical training program. By this, a suitable framework in terms of content and structure for palliative care teaching should be extracted. Methods  We performed guided interviews with 15 of the in total 36 lecturers responsible for the implementation of palliative care teaching at their respective medical schools. We focused on content, design and methods of implementation within the palliative care curriculum. Data was evaluated by content analysis according to Meuser and Nagel. Results  We found that a lack of recognition of this subject within the medical faculties, coupled with entrenched structures of an already packed syllabus, were considered to be most relevant for the given heterogeneity in the implementation process. Deficits in personnel, financial and time resources also contributed to the perceived deficits. Faced with these difficulties, inner- and cross-faculty teamwork and support, extracurricular activities as well as external funds have proven to be important resources. Discussion  To promote the implementation process, medical faculties need established palliative care structures that meet the interests and needs of the students more effectively. Analysis of structural needs (for instance, the amount of apprenticeships and teachings units) would be an important step to prove political claims. Moreover, the development of suitable and resource-saving teaching and assessment methods should be promoted. © Georg Thieme Verlag KG Stuttgart · New York.

Treatment of paint manufacturing wastewater by coagulation/electrochemical methods: Proposals for disposal and/or reuse of treated water.

PubMed

da Silva, Larissa F; Barbosa, Andreia D; de Paula, Heber M; Romualdo, Lincoln L; Andrade, Leonardo S

2016-09-15

This paper describes and discusses an investigation into the treatment of paint manufacturing wastewater (water-based acrylic texture) by coagulation (aluminum sulfate) coupled to electrochemical methods (BDD electrode). Two proposals are put forward, based on the results. The first proposal considers the feasibility of reusing wastewater treated by the methods separately and in combination, while the second examines the possibility of its disposal into water bodies. To this end, parameters such as toxicity, turbidity, color, organic load, dissolved aluminum, alkalinity, hardness and odor are evaluated. In addition, the proposal for water reuse is strengthened by the quality of the water-based paints produced using the wastewater treated by the two methods (combined and separate), which was evaluated based on the typical parameters for the quality control of these products. Under optimized conditions, the use of the chemical coagulation (12 mL/L of Al2(SO4)3 dosage) treatment, alone, proved the feasibility of reusing the treated wastewater in the paint manufacturing process. However, the use of the electrochemical method (i = 10 mA/cm(2) and t = 90 min) was required to render the treated wastewater suitable for discharge into water bodies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Density of bunched threading dislocations in epitaxial GaN layers as determined using X-ray diffraction

NASA Astrophysics Data System (ADS)

Barchuk, M.; Holý, V.; Rafaja, D.

2018-04-01

X-ray diffraction is one of the most popular experimental methods employed for determination of dislocation densities, as it can recognize both the strain fields and the local lattice rotations produced by dislocations. The main challenge of the quantitative analysis of the dislocation density is the formulation of a suitable microstructure model, which describes the dislocation arrangement and the effect of the interactions between the strain fields from neighboring dislocations reliably in order to be able to determine the dislocation densities precisely. The aim of this study is to prove the capability of X-ray diffraction and two computational methods, which are frequently used for quantification of the threading dislocation densities from X-ray diffraction measurements, in the special case of partially bunched threading dislocations. The first method is based on the analysis of the dislocation-controlled crystal mosaicity, and the other one on the analysis of diffuse X-ray scattering from threading dislocations. The complementarity of both methods is discussed. Furthermore, it is shown how the complementarity of these methods can be used to improve the results of the quantitative analysis of bunched and thus inhomogeneously distributed threading dislocations and to get a better insight into the dislocation arrangement.

Quality by design approach for the separation of naproxcinod and its related substances by fused core particle technology column.

PubMed

Inugala, Ugandar Reddy; Pothuraju, Nageswara Rao; Vangala, Ranga Reddy

2013-01-01

This paper describes the development of a rapid, novel, stability-indicating gradient reversed-phase high-performance liquid chromatographic method and associated system suitability parameters for the analysis of naproxcinod in the presence of its related substances and degradents using a quality-by-design approach. All of the factors that affect the separation of naproxcinod and its impurities and their mutual interactions were investigated and robustness of the method was ensured. The method was developed using an Ascentis Express C8 150 × 4.6 mm, 2.7 µm column with a mobile phase containing a gradient mixture of two solvents. The eluted compounds were monitored at 230 nm, the run time was 20 min within which naproxcinod and its eight impurities were satisfactorily separated. Naproxcinod was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Naproxcinod was found to degrade significantly in acidic and basic conditions and to be stable in thermal, photolytic, oxidative and aqueous degradation conditions. The degradation products were satisfactorily resolved from the primary peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.

Colorimetric Glucose Assay Based on Magnetic Particles Having Pseudo-peroxidase Activity and Immobilized Glucose Oxidase.

PubMed

Martinkova, Pavla; Opatrilova, Radka; Kruzliak, Peter; Styriak, Igor; Pohanka, Miroslav

2016-05-01

Magnetic particles (MPs) are currently used as a suitable alternative for peroxidase in the construction of novel biosensors, analytic and diagnostic methods. Their better chemical and thermal stabilities predestine them as appropriate pseudo-enzymatic catalysts. In this point of view, our research was focused on preparation of simply and fast method for immobilization of glucose oxidase onto surface of MPs with peroxidase-like activity. Spectrophotometric method (wavelength 450 nm) optimized for glucose determination using modified MPs has been successfully developed. Concentration curve for optimization of method was assayed, and Michaelis-Menten constant (K m) calculated, maximum reaction rate (V max), limit of detection, and correlation coefficient were determined to be 0.13 mmol/l (2.34 mg/dl), 1.79 pkat, 3.74 µmol/l (0.067 mg/dl), and 0.996, respectively. Interferences of other sugars such as sucrose, sorbitol, deoxyribose, maltose, and fructose were determined as well as effect of substances presenting in plasma (ascorbic acid, reduced glutathione, trolox, and urea). Results in comparison with positive and negative controls showed no interferences of the other sugars and no influence of plasma substances to measuring of glucose. The constructed method showed corresponding results with linear dependence and a correlation coefficient of 0.997. Possibility of repeated use of modified MPs was successfully proved.

Comparison of mid-infrared transmission spectroscopy with biochemical methods for the determination of macronutrients in human milk.

PubMed

Silvestre, Dolores; Fraga, Miriam; Gormaz, María; Torres, Ester; Vento, Máximo

2014-07-01

The variability of human milk (HM) composition renders analysis of its components essential for optimal nutrition of preterm fed either with donor's or own mother's milk. To fulfil this requirement, various analytical instruments have been subjected to scientific and clinical evaluation. The objective of this study was to evaluate the suitability of a rapid method for the analysis of macronutrients in HM as compared with the analytical methods applied by cow's milk industry. Mature milk from 39 donors was analysed using an infrared human milk analyser (HMA) and compared with biochemical reference laboratory methods. The statistical analysis was based on the use of paired data tests. The use of an infrared HMA for the analysis of lipids, proteins and lactose in HM proved satisfactory as regards the rapidity, simplicity and the required sample volume. The instrument afforded good linearity and precision in application to all three nutrients. However, accuracy was not acceptable when compared with the reference methods, with overestimation of the lipid content and underestimation of the amount of proteins and lactose contents. The use of mid-infrared HMA might become the standard for rapid analysis of HM once standardisation and rigorous and systematic calibration is provided. © 2012 John Wiley & Sons Ltd.

A Method for Extracting Road Boundary Information from Crowdsourcing Vehicle GPS Trajectories.

PubMed

Yang, Wei; Ai, Tinghua; Lu, Wei

2018-04-19

Crowdsourcing trajectory data is an important approach for accessing and updating road information. In this paper, we present a novel approach for extracting road boundary information from crowdsourcing vehicle traces based on Delaunay triangulation (DT). First, an optimization and interpolation method is proposed to filter abnormal trace segments from raw global positioning system (GPS) traces and interpolate the optimization segments adaptively to ensure there are enough tracking points. Second, constructing the DT and the Voronoi diagram within interpolated tracking lines to calculate road boundary descriptors using the area of Voronoi cell and the length of triangle edge. Then, the road boundary detection model is established integrating the boundary descriptors and trajectory movement features (e.g., direction) by DT. Third, using the boundary detection model to detect road boundary from the DT constructed by trajectory lines, and a regional growing method based on seed polygons is proposed to extract the road boundary. Experiments were conducted using the GPS traces of taxis in Beijing, China, and the results show that the proposed method is suitable for extracting the road boundary from low-frequency GPS traces, multi-type road structures, and different time intervals. Compared with two existing methods, the automatically extracted boundary information was proved to be of higher quality.

A Method for Extracting Road Boundary Information from Crowdsourcing Vehicle GPS Trajectories

PubMed Central

Yang, Wei

2018-01-01

Crowdsourcing trajectory data is an important approach for accessing and updating road information. In this paper, we present a novel approach for extracting road boundary information from crowdsourcing vehicle traces based on Delaunay triangulation (DT). First, an optimization and interpolation method is proposed to filter abnormal trace segments from raw global positioning system (GPS) traces and interpolate the optimization segments adaptively to ensure there are enough tracking points. Second, constructing the DT and the Voronoi diagram within interpolated tracking lines to calculate road boundary descriptors using the area of Voronoi cell and the length of triangle edge. Then, the road boundary detection model is established integrating the boundary descriptors and trajectory movement features (e.g., direction) by DT. Third, using the boundary detection model to detect road boundary from the DT constructed by trajectory lines, and a regional growing method based on seed polygons is proposed to extract the road boundary. Experiments were conducted using the GPS traces of taxis in Beijing, China, and the results show that the proposed method is suitable for extracting the road boundary from low-frequency GPS traces, multi-type road structures, and different time intervals. Compared with two existing methods, the automatically extracted boundary information was proved to be of higher quality. PMID:29671792

Finite-key analysis for quantum key distribution with weak coherent pulses based on Bernoulli sampling

NASA Astrophysics Data System (ADS)

Kawakami, Shun; Sasaki, Toshihiko; Koashi, Masato

2017-07-01

An essential step in quantum key distribution is the estimation of parameters related to the leaked amount of information, which is usually done by sampling of the communication data. When the data size is finite, the final key rate depends on how the estimation process handles statistical fluctuations. Many of the present security analyses are based on the method with simple random sampling, where hypergeometric distribution or its known bounds are used for the estimation. Here we propose a concise method based on Bernoulli sampling, which is related to binomial distribution. Our method is suitable for the Bennett-Brassard 1984 (BB84) protocol with weak coherent pulses [C. H. Bennett and G. Brassard, Proceedings of the IEEE Conference on Computers, Systems and Signal Processing (IEEE, New York, 1984), Vol. 175], reducing the number of estimated parameters to achieve a higher key generation rate compared to the method with simple random sampling. We also apply the method to prove the security of the differential-quadrature-phase-shift (DQPS) protocol in the finite-key regime. The result indicates that the advantage of the DQPS protocol over the phase-encoding BB84 protocol in terms of the key rate, which was previously confirmed in the asymptotic regime, persists in the finite-key regime.

On the suitability of refractometry for the analysis of glucose in blood-derived fluids.

PubMed

Zirk, K; Poetzschke, H

2004-07-01

Refractometry is the determination of the optical refractive index of a substance or a mixture of substances. It is a very sensitive method for the detection and quantification of dissolved analytes, but it is incapable of distinguishing between different analytes. The aim of this investigation was to determine the principle suitability of refractometry for the quantification of glucose (blood sugar) in blood and various blood fluids which can readily be obtained for medical diagnosis, in particular blood plasma, blood serum, and their ultrafiltrates. After the oral intake of freshly dissolved alpha-glucose, the in vivo blood contents of the alpha and beta anomers of glucose were found to be in an at least approximate equilibrium at all times. This observation is a prerequisite for a refractometrical determination of glucose due to the fact that both molecule forms have different refractive index increments. An assessment of the glucose content in untreated blood fluids was not possible, since no suitable relationship to the refractive index was found, most probably due to the influence of the many other substances present in blood on this parameter. However, after removal of certain macromolecules by ultrafiltration, value pairs showed a high level of correlation, providing the nominal molecular weight limit (cut-off) of the ultrafilter used possessed a maximum of 300 kDa. Besides macromolecules, the osmolality of the fluids undergoing measurement also proved to be a considerable interfering factor, particularly when values were outside the normal physiological range between 285 and 293 mmol/L. If a clinical application of this method is to be contemplated it is imperative (1) that blood cells are separated and removed, (2) that macromolecules present in plasma or serum are removed, e.g. by ultrafiltration, and (3) that beyond the results presented the influence of all small molecules other than glucose on the overall refractive index be determined and included in the calculation of analysis results.

Comparative investigations on the efficacy of articaine 4% (epinephrine 1:200,000) and articaine 2% (epinephrine 1:200,000) in local infiltration anaesthesia in dentistry--a randomised double-blind study.

PubMed

Hintze, A; Paessler, L

2006-06-01

A randomised double-blind study investigated 155 patients with tooth extractions in the mandibular and maxillary jaws for a loss of anaesthetic potency when reducing the concentration of the active in articaine solutions. Tests were performed on the preparations of articaine 4% with a 1:200,000 addition of epinephrine (Ultracain D-S) and articaine 2% with a 1:200,000 addition of epinephrine (Ultracain 2%-Suprarenin). Local infiltration anaesthesia was the chosen method of anaesthesia. The most noticeable difference observed between the two injection solutions concerned the duration of anaesthesia, which was significantly shortened under the low-dose solution. The 4% articaine solution did not prove superior in local anaesthetic effect. Articaine 2% with epinephrine 1:200,000, therefore, can be considered a suitable local anaesthetic for tooth extractions.

Extraction of Antioxidant Phenolic Compounds from Brewer’s Spent Grain: Optimization and Kinetics Modeling

PubMed Central

Sologubik, Carlos A.; Fernández, María B.; Manrique, Guillermo D.

2018-01-01

The kinetics of polyphenol extraction from brewer’s spent grain (BSG), using a batch system, ultrasound assistance, and microwave assistance and the evolution of antioxidant capacity of these extracts over time, were studied. The main parameters of extraction employed in the batch system were evaluated, and, by applying response surface analysis, the following optimal conditions were obtained: Liquid/solid ratio of 30:1 mL/g at 80 °C, using 72% (v/v) ethanol:water as the solvent system. Under these optimized conditions, ultrasound assistance demonstrated the highest extraction rate and equilibrium yield, as well as shortest extraction times, followed by microwave assistance. Among the mathematical models used, Patricelli’s model proved the most suitable for describing the extraction kinetics for each method tested, and is therefore able to predict the response values and estimate the extraction rates and potential maximum yields in each case. PMID:29570683

A methodology for producing small scale rural land use maps in semi-arid developing countries using orbital imagery

NASA Technical Reports Server (NTRS)

Vangenderen, J. L. (Principal Investigator); Lock, B. F.

1976-01-01

The author has identified the following significant results. Results have shown that it is feasible to design a methodology that can provide suitable guidelines for operational production of small scale rural land use maps of semiarid developing regions from LANDSAT MSS imagery, using inexpensive and unsophisticated visual techniques. The suggested methodology provides immediate practical benefits to map makers attempting to produce land use maps in countries with limited budgets and equipment. Many preprocessing and interpretation techniques were considered, but rejected on the grounds that they were inappropriate mainly due to the high cost of imagery and/or equipment, or due to their inadequacy for use in operational projects in the developing countries. Suggested imagery and interpretation techniques, consisting of color composites and monocular magnification proved to be the simplest, fastest, and most versatile methods.

A Liouville type theorem for Lane-Emden systems involving the fractional Laplacian

NASA Astrophysics Data System (ADS)

Quaas, Alexander; Xia, Aliang

2016-08-01

We establish a Liouville type theorem for the fractional Lane-Emden system: {(-Δ)αu=vqin  RN,(-Δ)αv=upin  RN, where α \\in (0,1) , N>2α and p, q are positive real numbers and in an appropriate new range. To prove our result we will use the local realization of fractional Laplacian, which can be constructed as a Dirichlet-to-Neumann operator of a degenerate elliptic equation in the spirit of Caffarelli and Silvestre (2007 Commun. PDE 32 1245-60). Our proof is based on a monotonicity argument for suitable transformed functions and the method of moving planes in a half infinite cylinder ({IR}× S+N , where S+N is the half unit sphere in {{{R}}N+1} ) based on maximum principles which are obtained by barrier functions and a coupling argument using a fractional Sobolev trace inequality.

Smart Aquarium as Physics Learning Media for Renewable Energy

NASA Astrophysics Data System (ADS)

Desnita, D.; Raihanati, R.; Susanti, D.

2018-04-01

Smart aquarium has been developed as a learning media to visualize Micro Hydro Power Generator (MHPG). Its used aquarium water circulation system and Wind Power Generation (WPG) which generated through a wheel as a source. Its also used to teach about energy changes, circular motion and wheel connection, electromagnetic impact, and AC power circuit. The output power and system efficiency was adjusted through the adjustment of water level and wind speed. Specific targets in this research are: to achieved: (i) develop green aquarium technology that’s suitable to used as a medium of physics learning, (ii) improving quality of process and learning result at a senior high school student. Research method used development research by Borg and Gall, which includes preliminary studies, design, product development, expert validation, and product feasibility test, and vinalisation. The validation test by the expert states that props feasible to use. Limited trials conducted prove that this tool can improve students science process skills.

Sequence analysis of the canine mitochondrial DNA control region from shed hair samples in criminal investigations.

PubMed

Berger, C; Berger, B; Parson, W

2012-01-01

In recent years, evidence from domestic dogs has increasingly been analyzed by forensic DNA testing. Especially, canine hairs have proved most suitable and practical due to the high rate of hair transfer occurring between dogs and humans. Starting with the description of a contamination-free sample handling procedure, we give a detailed workflow for sequencing hypervariable segments (HVS) of the mtDNA control region from canine evidence. After the hair material is lysed and the DNA extracted by Phenol/Chloroform, the amplification and sequencing strategy comprises the HVS I and II of the canine control region and is optimized for DNA of medium-to-low quality and quantity. The sequencing procedure is based on the Sanger Big-dye deoxy-terminator method and the separation of the sequencing reaction products is performed on a conventional multicolor fluorescence detection capillary electrophoresis platform. Finally, software-aided base calling and sequence interpretation are addressed exemplarily.

Restriction endonuclease analysis as a taxonomic tool in the study of pig isolates belonging to the Australis serogroup of Leptospira interrogans.

PubMed Central

Ellis, W A; Montgomery, J M; Thiermann, A B

1991-01-01

Restriction endonuclease analysis was performed on DNAs from the type strains of the Australis serogroup of Leptospira interrogans by using 20 restriction enzymes, and the electrophoretic patterns obtained were compared with patterns obtained from 162 Australis serogroup isolates from pigs. It proved to be a quick and reliable method for typing such strains. All of the pig isolates were identified as either serovar bratislava or muenchen. It also showed differences at the subserovar level which may be important in (i) understanding the epidemiology of the Australis serogroup, (ii) the development of suitable vaccines, and (iii) pathogenesis and pathogenicity studies. Two genotypes (B2b and M2) accounted for 92% of isolates from aborted or stillborn piglets, while a third genotype (B2a) was the only one recovered from the brains of piglets with meningitis. Images PMID:1647408

Restriction endonuclease analysis as a taxonomic tool in the study of pig isolates belonging to the Australis serogroup of Leptospira interrogans.

PubMed

Ellis, W A; Montgomery, J M; Thiermann, A B

1991-05-01

Restriction endonuclease analysis was performed on DNAs from the type strains of the Australis serogroup of Leptospira interrogans by using 20 restriction enzymes, and the electrophoretic patterns obtained were compared with patterns obtained from 162 Australis serogroup isolates from pigs. It proved to be a quick and reliable method for typing such strains. All of the pig isolates were identified as either serovar bratislava or muenchen. It also showed differences at the subserovar level which may be important in (i) understanding the epidemiology of the Australis serogroup, (ii) the development of suitable vaccines, and (iii) pathogenesis and pathogenicity studies. Two genotypes (B2b and M2) accounted for 92% of isolates from aborted or stillborn piglets, while a third genotype (B2a) was the only one recovered from the brains of piglets with meningitis.

Fluorescence spectroscopy and molecular weight distribution of extracellular polymers from full-scale activated sludge biomass.

PubMed

Esparza-Soto, M; Westerhoff, P K

2001-01-01

Two fractions of extracellular polymer substances (EPSs), soluble and readily extractable (RE), were characterised in terms of their molecular weight distributions (MWD) and 3-D excitation-emission-matrix (EEM) fluorescence spectroscopy signatures. The EPS fractions were different: the soluble EPSs were composed mainly of high molecular weight compounds, while the RE EPSs were composed of small molecular weight compounds. Contrary to previous thought, EPS may not be considered only as macromolecular because most organic matter present in both fractions had low molecular weight. Three different fluorophore peaks were identified in the EEM fluorescence spectra. Two peaks were attributed to protein-like fluorophores, and the third to a humic-like fluorophore. Fluorescence signatures were different from other previously published signatures for marine and riverine environments. EEM spectroscopy proved to be a suitable method that may be used to characterise and trace organic matter of bacterial origin in wastewater treatment operations.

Carbon materials modified by plasma treatment as electrodes for supercapacitors

NASA Astrophysics Data System (ADS)

Lota, Grzegorz; Tyczkowski, Jacek; Kapica, Ryszard; Lota, Katarzyna; Frackowiak, Elzbieta

The carbon material was modified by RF plasma with various reactive gases: O 2, Ar and CO 2. Physicochemical properties of the final carbon products were characterized using different techniques such as gas adsorption method and XPS. Plasma modified materials enriched in oxygen functionalities were investigated as electrodes for supercapacitors in acidic medium. The electrochemical measurements have been carried out using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy. The electrochemical measurements have confirmed that capacity characteristics are closely connected with a type of plasma exposition. Modification processes have an influence on the kind and amount of surface functional groups in the carbon matrix. The moderate increase of capacity of carbon materials modified by plasma has been observed using symmetric two-electrode systems. Whereas investigations made in three-electrode system proved that the suitable selection of plasma modification parameters allows to obtain promising negative and positive electrode materials for supercapacitor application.

Local multiplicative Schwarz algorithms for convection-diffusion equations

NASA Technical Reports Server (NTRS)

Cai, Xiao-Chuan; Sarkis, Marcus

1995-01-01

We develop a new class of overlapping Schwarz type algorithms for solving scalar convection-diffusion equations discretized by finite element or finite difference methods. The preconditioners consist of two components, namely, the usual two-level additive Schwarz preconditioner and the sum of some quadratic terms constructed by using products of ordered neighboring subdomain preconditioners. The ordering of the subdomain preconditioners is determined by considering the direction of the flow. We prove that the algorithms are optimal in the sense that the convergence rates are independent of the mesh size, as well as the number of subdomains. We show by numerical examples that the new algorithms are less sensitive to the direction of the flow than either the classical multiplicative Schwarz algorithms, and converge faster than the additive Schwarz algorithms. Thus, the new algorithms are more suitable for fluid flow applications than the classical additive or multiplicative Schwarz algorithms.

FBMC receiver for multi-user asynchronous transmission on fragmented spectrum

NASA Astrophysics Data System (ADS)

Doré, Jean-Baptiste; Berg, Vincent; Cassiau, Nicolas; Kténas, Dimitri

2014-12-01

Relaxed synchronization and access to fragmented spectrum are considered for future generations of wireless networks. Frequency division multiple access for filter bank multicarrier (FBMC) modulation provides promising performance without strict synchronization requirements contrary to conventional orthogonal frequency division multiplexing (OFDM). The architecture of a FBMC receiver suitable for this scenario is considered. Carrier frequency offset (CFO) compensation is combined with intercarrier interference (ICI) cancellation and performs well under very large frequency offsets. Channel estimation and interpolation had to be adapted and proved effective even for heavily fragmented spectrum usage. Channel equalization can sustain large delay spread. Because all the receiver baseband signal processing functionalities are proposed in the frequency domain, the overall architecture is suitable for multiuser asynchronous transmission on fragmented spectrum.

Characterization of volume holographic optical elements recorded in Bayfol HX photopolymer for solar photovoltaic applications.

PubMed

Marín-Sáez, Julia; Atencia, Jesús; Chemisana, Daniel; Collados, María-Victoria

2016-03-21

Volume Holographic Optical Elements (HOEs) present interesting characteristics for photovoltaic applications as they can select spectrum for concentrating the target bandwidth and avoiding non-desired wavelengths, which can cause the decrease of the performance on the cell, for instance by overheating it. Volume HOEs have been recorded on Bayfol HX photopolymer to test the suitability of this material for solar concentrating photovoltaic systems. The HOEs were recorded at 532 nm and provided a dynamic range, reaching close to 100% efficiency at 800 nm. The diffracted spectrum had a FWHM of 230 nm when illuminating at Bragg angle. These characteristics prove HOEs recorded on Bayfol HX photopolymer are suitable for concentrating solar light onto photovoltaic cells sensitive to that wavelength range.

Existence and asymptotic behavior of nontrivial solutions to the Swift-Hohenberg equation

NASA Astrophysics Data System (ADS)

Marino, G.; Mosconi, S.

2017-12-01

In this paper, we discuss several results regarding existence, non-existence and asymptotic properties of solutions to u⁗ + qu″ + f (u) = 0, under various hypotheses on the parameter q and on the potential F (t) = ∫0t f (s) ds, generally assumed to be bounded from below. We prove a non-existence result in the case q ≤ 0 and an existence result of periodic solution for: 1) almost every suitably small (depending on F), positive values of q; 2) all suitably large (depending on F) values of q. Finally, we describe some conditions on F which ensure that some (or all) solutions uq to the equation satisfy ‖uq‖∞ → 0, as q ↓ 0.

Area laser crystallized LTPS TFTs with implanted contacts for active matrix OLED displays

NASA Astrophysics Data System (ADS)

Persidis, Efstathios; Baur, Holger; Pieralisi, Fabio; Schalberger, Patrick; Fruehauf, Norbert

2008-03-01

We have developed a four mask low temperature poly-Si (LTPS) TFT process for p- and n-channel devices. Our PECVD deposited amorphous silicon is recrystallized to polycrystalline silicon with single area excimer laser crystallization while formation of drain and source is carried out with self aligned ion beam implantation. We have investigated implantation parameters, suitability of various metallizations as well as laser activation and annealing procedures. To prove the potential capability of our devices, which are suitable for conventional and inverted OLEDs alike, we have produced several functional active matrix backplanes implementing different pixel circuits. Our active matrix backplane process has been customized to drive small molecules as well as polymers, regardless if top or bottom emitting.

Students Leaving the STEM Pipeline: An Investigation of Their Attitudes and the Influence of Significant Others on Their Study Choice

ERIC Educational Resources Information Center

Korpershoek, Hanke; Kuyper, Hans; Bosker, Roel; van der Werf, Greetje

2013-01-01

The main aim of the present study was to investigate why some students do not continue in science-oriented studies in higher education despite that their previous career in secondary education proved that they were interested and suitably qualified to do so. We introduced a new approach to deal with these students' attitudes towards science,…

Optimising magnetic resonance image quality of the ear in healthy dogs.

PubMed

Wolf, Davina; Lüpke, Matthias; Wefstaedt, Patrick; Klopmann, Thilo; Nolte, Ingo; Seifert, Hermann

2011-03-01

The aim of this study was to develop an examination protocol for magnetic resonance imaging, in order to display diagnostically important information of the canine middle and inner ear. To ensure that this protocol could also be used as a basis for determining pathological changes, the anatomical structures of the ear were presented in detail. To minimise stress through anaesthesia in live animals, preliminary examinations were carried out on four dog cadavers. During these initial examinations, three-dimensional (3D) sequences proved to be superior to two-dimensional ones. Therefore, only 3D sequences were applied for the main examinations performed on six clinically healthy Beagles. The anonymised MR images were rated by three experienced reviewers using a five-point scale. The most valuable sequence was a T2-weighted CISS sequence (TR = 16.7 ms, TE = 8.08 ms). This sequence proved to be most suitable for illustrating the inner ear structures and enabled good tissue contrasts. The sequence ranked second best was also a T2-weighted DESS sequence (TR = 19 ms, TE = 6 ms), allowing the imaging of the tympanic cavity and enabling 3D reconstruction due to its isotropic voxels. Due to low contrast and strong noise, the other sequences (TSE, FISP, MP RAGE) were not suitable for anatomical illustration of the middle and inner ear.

Application of a vascular graft material (Solcograft-P) in experimental surgery.

PubMed

Nemes, A; Acsády, G; Fraefel, W; Lichti, H; Monos, E; Oertli, R; Somogyi, E; Sótonyi, P

1985-09-01

The implantation and post-implantation behaviour of a Solcograft-P vascular prosthesis in the aortic, aorto-iliac, carotid and vena caval positions in dogs was studied up to 100 d post-surgery in order to assess the suitability of this vascular material for use in man. Solcograft-P is prepared from the carotid arteries of calves by crosslinking the collagen stroma using adipyl dichloride. During the postoperative follow-up period of 3 month, 100% of the aortal grafts, 80% of the aorto-iliac bypasses, 60% of the vena caval grafts and 35% of the carotid implants remained patent. The biochemical properties of the Solcograft-P are better than those of Solcograft, its predecessor. The intimal lining was consistently smooth and homogeneous in grafts of biological origin, and no aneurysm was observed. Infection and early thrombosis occured no more frequently than with other grafts. The new Solcograft-P, crosslinked via ester and amide groups, seems to represent a real improvement over Solcograft. Our results suggest that Solcograft-P should prove valuable in various cases of reconstructive vascular surgery of the lower limb, especially when the autologous vena saphena magna is not available, and its mechanical properties may well prove suitable for both arterial and venous replacement.

Predicting drug penetration across the blood-brain barrier: comparison of micellar liquid chromatography and immobilized artificial membrane liquid chromatography.

PubMed

De Vrieze, Mike; Lynen, Frédéric; Chen, Kai; Szucs, Roman; Sandra, Pat

2013-07-01

Several in vitro methods have been tested for their ability to predict drug penetration across the blood-brain barrier (BBB) into the central nervous system (CNS). In this article, the performance of a variety of micellar liquid chromatographic (MLC) methods and immobilized artificial membrane (IAM) liquid chromatographic approaches were compared for a set of 45 solutes. MLC measurements were performed on a C18 column with sodium dodecyl sulfate (SDS), polyoxyethylene (23) lauryl ether (Brij35), or sodium deoxycholate (SDC) as surfactant in the micellar mobile phase. IAM liquid chromatography measurements were performed with Dulbecco's phosphate-buffered saline (DPBS) and methanol as organic modifier in the mobile phase. The corresponding retention and computed descriptor data for each solute were used for construction of models to predict transport across the blood-brain barrier (log BB). All data were correlated with experimental log BB values and the relative performance of the models was studied. SDS-based models proved most suitable for prediction of log BB values, followed closely by a simplified IAM method, in which it could be observed that extrapolation of retention data to 0% modifier in the mobile phase was unnecessary.

Detection of heavy metal Cd in polluted fresh leafy vegetables by laser-induced breakdown spectroscopy.

PubMed

Yao, Mingyin; Yang, Hui; Huang, Lin; Chen, Tianbing; Rao, Gangfu; Liu, Muhua

2017-05-10

In seeking a novel method with the ability of green analysis in monitoring toxic heavy metals residue in fresh leafy vegetables, laser-induced breakdown spectroscopy (LIBS) was applied to prove its capability in performing this work. The spectra of fresh vegetable samples polluted in the lab were collected by optimized LIBS experimental setup, and the reference concentrations of cadmium (Cd) from samples were obtained by conventional atomic absorption spectroscopy after wet digestion. The direct calibration employing intensity of single Cd line and Cd concentration exposed the weakness of this calibration method. Furthermore, the accuracy of linear calibration can be improved a little by triple Cd lines as characteristic variables, especially after the spectra were pretreated. However, it is not enough in predicting Cd in samples. Therefore, partial least-squares regression (PLSR) was utilized to enhance the robustness of quantitative analysis. The results of the PLSR model showed that the prediction accuracy of the Cd target can meet the requirement of determination in food safety. This investigation presented that LIBS is a promising and emerging method in analyzing toxic compositions in agricultural products, especially combined with suitable chemometrics.

Quantification of paracetamol and 5-oxoproline in serum by capillary electrophoresis: Implication for clinical toxicology.

PubMed

Hložek, Tomáš; Křížek, Tomáš; Tůma, Petr; Bursová, Miroslava; Coufal, Pavel; Čabala, Radomír

2017-10-25

High anion gap metabolic acidosis frequently complicates acute paracetamol overdose and is generally attributed to lactic acidosis or compromised hepatic function. However, metabolic acidosis can also be caused by organic acid 5-oxoproline (pyroglutamic acid). Paracetamol's toxic intermediate, N-acetyl-p-benzoquinoneimine irreversibly binds to glutathione and its depletion leads to subsequent disruption of the gamma glutamyl cycle and an excessive 5-oxoproline generation. This is undoubtedly an underdiagnosed condition because measurement of serum 5-oxoproline level is not readily available. A simple, cost effective, and fast capillary electrophoresis method with diode array detection (DAD) for simultaneous measurement of both paracetamol (acetaminophen) and 5-oxoproline in serum was developed and validated. This method is highly suitable for clinical toxicology laboratory diagnostic, allowing rapid quantification of acidosis inducing organic acid 5-oxoproline present in cases of paracetamol overdose. The calibration dependence of the method was proved to be linear in the range of 1.3-250μgmL -1 , with adequate accuracy (96.4-107.8%) and precision (12.3%). LOQ equaled 1.3μgmL -1 for paracetamol and 4.9μgmL -1 for 5-oxoproline. Copyright © 2017 Elsevier B.V. All rights reserved.

Advantages of automation in plasma sample preparation prior to HPLC/MS/MS quantification: application to the determination of cilazapril and cilazaprilat in a bioequivalence study.

PubMed

Kolocouri, Filomila; Dotsikas, Yannis; Apostolou, Constantinos; Kousoulos, Constantinos; Soumelas, Georgios-Stefanos; Loukas, Yannis L

2011-01-01

An HPLC/MS/MS method characterized by complete automation and high throughput was developed for the determination of cilazapril and its active metabolite cilazaprilat in human plasma. All sample preparation and analysis steps were performed by using 2.2 mL 96 deep-well plates, while robotic liquid handling workstations were utilized for all liquid transfer steps, including liquid-liquid extraction. The whole procedure was very fast compared to a manual procedure with vials and no automation. The method also had a very short chromatographic run time of 1.5 min. Sample analysis was performed by RP-HPLC/MS/MS with positive electrospray ionization using multiple reaction monitoring. The calibration curve was linear in the range of 0.500-300 and 0.250-150 ng/mL for cilazapril and cilazaprilat, respectively. The proposed method was fully validated and proved to be selective, accurate, precise, reproducible, and suitable for the determination of cilazapril and cilazaprilat in human plasma. Therefore, it was applied to a bioequivalence study after per os administration of 2.5 mg tablet formulations of cilazapril.

Estimation of tiger densities in India using photographic captures and recaptures

USGS Publications Warehouse

Karanth, U.; Nichols, J.D.

1998-01-01

Previously applied methods for estimating tiger (Panthera tigris) abundance using total counts based on tracks have proved unreliable. In this paper we use a field method proposed by Karanth (1995), combining camera-trap photography to identify individual tigers based on stripe patterns, with capture-recapture estimators. We developed a sampling design for camera-trapping and used the approach to estimate tiger population size and density in four representative tiger habitats in different parts of India. The field method worked well and provided data suitable for analysis using closed capture-recapture models. The results suggest the potential for applying this methodology for estimating abundances, survival rates and other population parameters in tigers and other low density, secretive animal species with distinctive coat patterns or other external markings. Estimated probabilities of photo-capturing tigers present in the study sites ranged from 0.75 - 1.00. The estimated mean tiger densities ranged from 4.1 (SE hat= 1.31) to 11.7 (SE hat= 1.93) tigers/100 km2. The results support the previous suggestions of Karanth and Sunquist (1995) that densities of tigers and other large felids may be primarily determined by prey community structure at a given site.

Fast log P determination by ultra-high-pressure liquid chromatography coupled with UV and mass spectrometry detections.

PubMed

Henchoz, Yveline; Guillarme, Davy; Martel, Sophie; Rudaz, Serge; Veuthey, Jean-Luc; Carrupt, Pierre-Alain

2009-08-01

Ultra-high-pressure liquid chromatography (UHPLC) systems able to work with columns packed with sub-2 microm particles offer very fast methods to determine the lipophilicity of new chemical entities. The careful development of the most suitable experimental conditions presented here will help medicinal chemists for high-throughput screening (HTS) log P(oct) measurements. The approach was optimized using a well-balanced set of 38 model compounds and a series of 28 basic compounds such as beta-blockers, local anesthetics, piperazines, clonidine, and derivatives. Different organic modifiers and hybrid stationary phases packed with 1.7-microm particles were evaluated in isocratic as well as gradient modes, and the advantages and limitations of tested conditions pointed out. The UHPLC approach offered a significant enhancement over the classical HPLC methods, by a factor 50 in the lipophilicity determination throughput. The hyphenation of UHPLC with MS detection allowed a further increase in the throughput. Data and results reported herein prove that the UHPLC-MS method can represent a progress in the HTS-measurement of lipophilicity due to its speed (at least a factor of 500 with respect to HPLC approaches) and to an extended field of application.

[Use of an iliac branched endoprostheis in endovascular treatment for an abdominal aortic aneurysm combined with aneurysms of both common iliac arteries].

PubMed

Imaev, T E; Kuchin, I V; Lepilin, P M; Kolegaev, A S; Medvedeva, I S; Komlev, A E; Akchurin, R S

An abdominal aortic aneurysm appears to be combined with aneurysmatic lesions of the common iliac arteries in 30-40% of cases. Like abdominal aortic aneurysms, aneurysms of the common iliac arteries rarely manifest themselves clinically. The lethality rate in case of rupture is comparable to that for rupture of an abdominal aortic aneurysm. During endoprosthetic repair of abdominal aortic aneurysms combined with aneurysms of the common iliac arteries, in order to prevent endoleaks and to improve the distal zone of fixation of endografts surgeons often resort to embolization of internal iliac arteries, which may lead to ischaemic postoperative complications. One of the methods of preserving pelvic blood flow is the use of an iliac branched endograft. A series of studies evaluating long-term outcomes demonstrated that this method proved to be both safe and effective, and with the suitable anatomy is a method of choice in high surgical risk patients. The present article deals with a clinical case report concerning bilateral endoprosthetic repair of the common iliac arteries, combined with endoprosthetic repair of an abdominal aortic aneurysm, with the description of technical peculiarities of implanting an iliac branched graft.

Image re-sampling detection through a novel interpolation kernel.

PubMed

Hilal, Alaa

2018-06-01

Image re-sampling involved in re-size and rotation transformations is an essential element block in a typical digital image alteration. Fortunately, traces left from such processes are detectable, proving that the image has gone a re-sampling transformation. Within this context, we present in this paper two original contributions. First, we propose a new re-sampling interpolation kernel. It depends on five independent parameters that controls its amplitude, angular frequency, standard deviation, and duration. Then, we demonstrate its capacity to imitate the same behavior of the most frequent interpolation kernels used in digital image re-sampling applications. Secondly, the proposed model is used to characterize and detect the correlation coefficients involved in re-sampling transformations. The involved process includes a minimization of an error function using the gradient method. The proposed method is assessed over a large database of 11,000 re-sampled images. Additionally, it is implemented within an algorithm in order to assess images that had undergone complex transformations. Obtained results demonstrate better performance and reduced processing time when compared to a reference method validating the suitability of the proposed approaches. Copyright © 2018 Elsevier B.V. All rights reserved.

Detection of explosives on the surface of banknotes by Raman hyperspectral imaging and independent component analysis.

PubMed

Almeida, Mariana R; Correa, Deleon N; Zacca, Jorge J; Logrado, Lucio Paulo Lima; Poppi, Ronei J

2015-02-20

The aim of this study was to develop a methodology using Raman hyperspectral imaging and chemometric methods for identification of pre- and post-blast explosive residues on banknote surfaces. The explosives studied were of military, commercial and propellant uses. After the acquisition of the hyperspectral imaging, independent component analysis (ICA) was applied to extract the pure spectra and the distribution of the corresponding image constituents. The performance of the methodology was evaluated by the explained variance and the lack of fit of the models, by comparing the ICA recovered spectra with the reference spectra using correlation coefficients and by the presence of rotational ambiguity in the ICA solutions. The methodology was applied to forensic samples to solve an automated teller machine explosion case. Independent component analysis proved to be a suitable method of resolving curves, achieving equivalent performance with the multivariate curve resolution with alternating least squares (MCR-ALS) method. At low concentrations, MCR-ALS presents some limitations, as it did not provide the correct solution. The detection limit of the methodology presented in this study was 50 μg cm(-2). Copyright © 2014 Elsevier B.V. All rights reserved.

[Determination of icaritin in rat plasma by HPLC-MS/MS].

PubMed

Liu, Hai-Pei; Meng, Fan-Hua; Guo, Ji-Fen; Si, Duan-Yun; Zhu, Xiao-Wei; Zhao, Yi-Min

2009-10-01

The paper is to report the development of a high-performance liquid chromatographic/tandem mass spectrometry (HPLC-MS/MS) method for the determination of icaritin (ICT) in rat plasma. After precipitated with acetonitrile from the plasma, ICT was isolated chromatographically on a Dikma C18 column. The mobile phase consisted of acetonitrile-water-acetic acid (72 : 28 : 1.5, v/v/v). Electrospray ionization (ESI) source was applied and operated in the positive ion mode. Multiple reaction monitoring (MRM) mode with the transitions of m/z 387 --> m/z 313 and m/z 331 --> m/z 315 were used to quantify ICT and the internal standard, respectively. The linear calibration curve was obtained in the concentration range of 2.5-1,000 ng x mL(-1). The lower limit of quantification was 2.5 ng x mL(-1). The inter- and intra-day precision (RSD) were less than 9.63%, and the accuracy (relative error) was within +/-7.42%. The method was proved to be suitable for the pharmacokinetics of ICT, which offers advantages of high sensitivity and selectivity.

Recent Advances in 3D Printing of Aliphatic Polyesters

PubMed Central

Frone, Adriana Nicoleta; Brandabur, Călin

2017-01-01

3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed. PMID:29295559

Models based on ultraviolet spectroscopy, polyphenols, oligosaccharides and polysaccharides for prediction of wine astringency.

PubMed

Boulet, Jean-Claude; Trarieux, Corinne; Souquet, Jean-Marc; Ducasse, Maris-Agnés; Caillé, Soline; Samson, Alain; Williams, Pascale; Doco, Thierry; Cheynier, Véronique

2016-01-01

Astringency elicited by tannins is usually assessed by tasting. Alternative methods involving tannin precipitation have been proposed, but they remain time-consuming. Our goal was to propose a faster method and investigate the links between wine composition and astringency. Red wines covering a wide range of astringency intensities, assessed by sensory analysis, were selected. Prediction models based on multiple linear regression (MLR) were built using UV spectrophotometry (190-400 nm) and chemical analysis (enological analysis, polyphenols, oligosaccharides and polysaccharides). Astringency intensity was strongly correlated (R(2) = 0.825) with tannin precipitation by bovine serum albumin (BSA). Wine absorbances at 230 nm (A230) proved more suitable for astringency prediction (R(2) = 0.705) than A280 (R(2) = 0.56) or tannin concentration estimated by phloroglucinolysis (R(2) = 0.59). Three variable models built with A230, oligosaccharides and polysaccharides presented high R(2) and low errors of cross-validation. These models confirmed that polysaccharides decrease astringency perception and indicated a positive relationship between oligosaccharides and astringency. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitation of acrylamide in foods by high-resolution mass spectrometry.

PubMed

Troise, Antonio Dario; Fiore, Alberto; Fogliano, Vincenzo

2014-01-08

Acrylamide detection still represents one of the hottest topics in food chemistry. Solid phase cleanup coupled to liquid chromatography separation and tandem mass spectrometry detection along with GC-MS detection are nowadays the gold standard procedure for acrylamide quantitation thanks to high reproducibility, good recovery, and low relative standard deviation. High-resolution mass spectrometry (HRMS) is particularly suitable for the detection of low molecular weight amides, and it can provide some analytical advantages over other MS techniques. In this paper a liquid chromatography (LC) method for acrylamide determination using HRMS detection was developed and compared to LC coupled to tandem mass spectrometry. The procedure applied a simplified extraction, no cleanup steps, and a 4 min chromatography. It proved to be solid and robust with an acrylamide mass accuracy of 0.7 ppm, a limit of detection of 2.65 ppb, and a limit of quantitation of 5 ppb. The method was tested on four acrylamide-containing foods: cookies, French fries, ground coffee, and brewed coffee. Results were perfectly in line with those obtained by LC-MS/MS.

High-Efficiency Visible Transmitting Polarizations Devices Based on the GaN Metasurface.

PubMed

Guo, Zhongyi; Xu, Haisheng; Guo, Kai; Shen, Fei; Zhou, Hongping; Zhou, Qingfeng; Gao, Jun; Yin, Zhiping

2018-05-15

Metasurfaces are capable of tailoring the amplitude, phase, and polarization of incident light to design various polarization devices. Here, we propose a metasurface based on the novel dielectric material gallium nitride (GaN) to realize high-efficiency modulation for both of the orthogonal linear polarizations simultaneously in the visible range. Both modulated transmitted phases of the orthogonal linear polarizations can almost span the whole 2π range by tailoring geometric sizes of the GaN nanobricks, while maintaining high values of transmission (almost all over 90%). At the wavelength of 530 nm, we designed and realized the beam splitter and the focusing lenses successfully. To further prove that our proposed method is suitable for arbitrary orthogonal linear polarization, we also designed a three-dimensional (3D) metalens that can simultaneously focus the X -, Y -, 45°, and 135° linear polarizations on spatially symmetric positions, which can be applied to the linear polarization measurement. Our work provides a possible method to achieve high-efficiency multifunctional optical devices in visible light by extending the modulating dimensions.

Highly Modified Cellulose Nanocrystals and Formation of Epoxy-CNC Nanocomposites.

PubMed

Abraham, Eldho; Kam, Doron; Nevo, Yuval; Slattegard, Rikard; Rivkin, Amit; Lapidot, Shaul; Shoseyov, Oded

2016-10-05

This work presents an environmentally friendly, iodine-catalysed chemical modification method to generate highly hydrophobic, optically active cellulose nanocrystals (CNC). The high degree of ester substitution (DS=2.18), hydrophobicity, crystalline behaviour and optical activity of the generated acetylated CNC (Ac-CNC) were quantified by TEM, FTIR, solid 13C NMR, contact angle, XRD and POM analyses. Ac-CNC possessing substantial enhancement in thermal stability (16.8%) and forms thin films with interlayer distance of 50-150 nm, presenting cavities suitable for entrapping nano and micro particles. Generated Ac-CNC proved as an effective reinforcing agent in hydrophobic polymer matrices for fabricating high performance nanocomposites. When integrated at a very low weight percentage (0.5%) in an epoxy matrix, Ac-CNC provided for a 73% increase in tensile strength and a 98% increase in modulus, demonstrating its remarkable reinforcing potential and effective stress transfer behaviour. The method of modification and the unique properties of the modified CNC (hydrophobicity, crystallinity, reinforcing ability and optical activity) render them a novel bionanomaterial for a range of multipurpose applications.

A combined approach based on MAF analysis and AHP method to fault detection mapping: A case study from a gas field, southwest of Iran

NASA Astrophysics Data System (ADS)

Shakiba, Sima; Asghari, Omid; Khah, Nasser Keshavarz Faraj

2018-01-01

A combined geostatitical methodology based on Min/Max Auto-correlation Factor (MAF) analysis and Analytical Hierarchy Process (AHP) is presented to generate a suitable Fault Detection Map (FDM) through seismic attributes. Five seismic attributes derived from a 2D time slice obtained from data related to a gas field located in southwest of Iran are used including instantaneous amplitude, similarity, energy, frequency, and Fault Enhancement Filter (FEF). The MAF analysis is implemented to reduce dimension of input variables, and then AHP method is applied on three obtained de-correlated MAF factors as evidential layer. Three Decision Makers (DMs) are used to construct PCMs for determining weights of selected evidential layer. Finally, weights obtained by AHP were multiplied in normalized valued of each alternative (MAF layers) and the concluded weighted layers were integrated in order to prepare final FDM. Results proved that applying algorithm proposed in this study generate a map more acceptable than the each individual attribute and sharpen the non-surface discontinuities as well as enhancing continuity of detected faults.

Finite-horizon differential games for missile-target interception system using adaptive dynamic programming with input constraints

NASA Astrophysics Data System (ADS)

Sun, Jingliang; Liu, Chunsheng

2018-01-01

In this paper, the problem of intercepting a manoeuvring target within a fixed final time is posed in a non-linear constrained zero-sum differential game framework. The Nash equilibrium solution is found by solving the finite-horizon constrained differential game problem via adaptive dynamic programming technique. Besides, a suitable non-quadratic functional is utilised to encode the control constraints into a differential game problem. The single critic network with constant weights and time-varying activation functions is constructed to approximate the solution of associated time-varying Hamilton-Jacobi-Isaacs equation online. To properly satisfy the terminal constraint, an additional error term is incorporated in a novel weight-updating law such that the terminal constraint error is also minimised over time. By utilising Lyapunov's direct method, the closed-loop differential game system and the estimation weight error of the critic network are proved to be uniformly ultimately bounded. Finally, the effectiveness of the proposed method is demonstrated by using a simple non-linear system and a non-linear missile-target interception system, assuming first-order dynamics for the interceptor and target.

Degradation of naproxen by UV, VUV photolysis and their combination.

PubMed

Arany, Eszter; Szabó, Rita Katalin; Apáti, László; Alapi, Tünde; Ilisz, István; Mazellier, Patrick; Dombi, András; Gajda-Schrantz, Krisztina

2013-11-15

Naproxen is a widely used nonsteroidal anti-inflammatory drug. Recently, this medicine was detected both in natural waters (up to 1.5 μg L(-1)) and in sewage treatment plant effluents (up to 5.2 μg L(-1)). Moreover, naproxen is only partly eliminated by classical processes used in sewage treatment plants. Therefore, its degradation is of utmost interest. Advanced oxidation processes proved to be the most suitable methods for the elimination of persistent organic contaminants. In this work ultraviolet (UV, 254 nm), vacuum ultraviolet photolysis (VUV, 172 nm) and their combination (UV/VUV, 254/185 nm) were investigated. The efficiency of the methods increased in the following order: UV < VUV < UV/VUV photolysis. However, VUV irradiation was found to mineralize the contaminant molecule most effectively. The chemical structures of three out of four aromatic by-products and of some aliphatic carboxylic acids were presumed. The effects of dissolved O2 and the initial concentration of naproxen on the degradation were also investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

Secure distribution for high resolution remote sensing images

NASA Astrophysics Data System (ADS)

Liu, Jin; Sun, Jing; Xu, Zheng Q.

2010-09-01

The use of remote sensing images collected by space platforms is becoming more and more widespread. The increasing value of space data and its use in critical scenarios call for adoption of proper security measures to protect these data against unauthorized access and fraudulent use. In this paper, based on the characteristics of remote sensing image data and application requirements on secure distribution, a secure distribution method is proposed, including users and regions classification, hierarchical control and keys generation, and multi-level encryption based on regions. The combination of the three parts can make that the same remote sensing images after multi-level encryption processing are distributed to different permission users through multicast, but different permission users can obtain different degree information after decryption through their own decryption keys. It well meets user access control and security needs in the process of high resolution remote sensing image distribution. The experimental results prove the effectiveness of the proposed method which is suitable for practical use in the secure transmission of remote sensing images including confidential information over internet.

The exponentiated Hencky-logarithmic strain energy. Part II: Coercivity, planar polyconvexity and existence of minimizers

NASA Astrophysics Data System (ADS)

Neff, Patrizio; Lankeit, Johannes; Ghiba, Ionel-Dumitrel; Martin, Robert; Steigmann, David

2015-08-01

We consider a family of isotropic volumetric-isochoric decoupled strain energies based on the Hencky-logarithmic (true, natural) strain tensor log U, where μ > 0 is the infinitesimal shear modulus, is the infinitesimal bulk modulus with the first Lamé constant, are dimensionless parameters, is the gradient of deformation, is the right stretch tensor and is the deviatoric part (the projection onto the traceless tensors) of the strain tensor log U. For small elastic strains, the energies reduce to first order to the classical quadratic Hencky energy which is known to be not rank-one convex. The main result in this paper is that in plane elastostatics the energies of the family are polyconvex for , extending a previous finding on its rank-one convexity. Our method uses a judicious application of Steigmann's polyconvexity criteria based on the representation of the energy in terms of the principal invariants of the stretch tensor U. These energies also satisfy suitable growth and coercivity conditions. We formulate the equilibrium equations, and we prove the existence of minimizers by the direct methods of the calculus of variations.

Asymmetric flow field-flow fractionation (AF4) for the quantification of nanoparticle release from tablets during dissolution testing.

PubMed

Engel, A; Plöger, M; Mulac, D; Langer, K

2014-01-30

Nanoparticles composed of poly(DL-lactide-co-glycolide) (PLGA) represent promising colloidal drug carriers for improved drug targeting. Although most research activities are focused on intravenous application of these carriers the peroral administration is described to improve bioavailability of poorly soluble drugs. Based on these insights the manuscript describes a model tablet formulation for PLGA-nanoparticles and especially its analytical characterisation with regard to a nanosized drug carrier. Besides physico-chemical tablet characterisation according to pharmacopoeias the main goal of the study was the development of a suitable analytical method for the quantification of nanoparticle release from tablets. An analytical flow field-flow fractionation (AF4) method was established and validated which enables determination of nanoparticle content in solid dosage forms as well as quantification of particle release during dissolution testing. For particle detection a multi-angle light scattering (MALS) detector was coupled to the AF4-system. After dissolution testing, the presence of unaltered PLGA-nanoparticles was successfully proved by dynamic light scattering and scanning electron microscopy. Copyright © 2013 Elsevier B.V. All rights reserved.

A description of the standardized measurement procedures and recommended threshold limit values for biological hazards in Germany.

PubMed

Rieger, M A; Lohmeyer, M; Nübling, M; Neuhaus, S; Diefenbach, H; Hofmann, F

2005-05-01

On the basis of EU directives 89/391/EEC (to encourage improvements in the safety and health of workers at work) and 2000/54/EC (on the protection of workers from risks related to exposure to biological agents at work), biological hazards at work have to be assessed and preventive measures have to be introduced in all member states of the EU. In Germany, national legislation (Biological Agents Ordinance - BioStoffV and Technical Rules on Biological Agents, TRBA) and recommendations of workers' compensation boards define standardized methods for the assessment of airborne mold, bacteria, and endotoxins. This article describes policies and practices in Germany for measurement of airborne bioaerosols and for interpretation of measurements relative to the standards. As an example, methods and results of measurements in agriculture are shown. The standardized measurement procedures proved suitable for use in livestock buildings. The results of the exploratory measurements in different livestock buildings confirmed the often high concentrations of airborne biological hazards in agriculture that are reported in the literature.

[Modeling continuous scaling of NDVI based on fractal theory].

PubMed

Luan, Hai-Jun; Tian, Qing-Jiu; Yu, Tao; Hu, Xin-Li; Huang, Yan; Du, Ling-Tong; Zhao, Li-Min; Wei, Xi; Han, Jie; Zhang, Zhou-Wei; Li, Shao-Peng

2013-07-01

Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc. Utilizing single sensor image, fractal methodology was utilized to solve these problems. Taking NDVI (computed by land surface radiance) as example and based on Enhanced Thematic Mapper Plus (ETM+) image, a scheme was proposed to model continuous scaling of retrievals. Then the experimental results indicated that: (a) For NDVI, scale effect existed, and it could be described by fractal model of continuous scaling; (2) The fractal method was suitable for validation of NDVI. All of these proved that fractal was an effective methodology of studying scaling of quantitative remote sensing.

An impedimetric immunosensor for highly sensitive detection of IL-8 in human serum and saliva samples: A new surface modification method by 6-phosphonohexanoic acid for biosensing applications.

PubMed

Aydın, Elif Burcu; Sezgintürk, Mustafa Kemal

2018-08-01

In this study, we fabricated a sensitive and label-free impedimetric immunosensor based on 6-phosphonohexanoic acid (PHA) modified ITO electrode for detection of interleukin-8 (IL-8) in human serum and saliva. PHA was first employed to cancer biomarker sensing platform. Anti-IL-8 antibody was used as a biorecognition element and the detection principle of this immunosensor was based on monitoring specific interaction between anti-IL-8 antibody and IL-8 antigen. The morphological characterization of each electrode modification step was analyzed by scanning electron microscopy (SEM), SEM-energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) while electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and single frequency impedance (SFI) techniques. Moreover, the antibody immobilization on the electrode surface was proved Fourier-transform infrared spectroscopy (FTIR) and Raman Spectroscopy. This proposed impedimetric immunosensor exhibited good performances with a wide linear in the range from 0.02 pg/mL to 3 pg/mL as well as a relative low detection limit of 6 fg/mL. The impedimetric immunosensor had a good specificity, stability and reproducibility. This study proved that PHA was a suitable interface material to fabricate an electrochemical biosensor. Copyright © 2018 Elsevier Inc. All rights reserved.

Effectiveness of the online weight reduction program KiloCoach™ and comparison with other evaluated commercial direct intervention and online programs.

PubMed

Longin, Rita; Grasse, Marina; Aspalter, Rosa; Waldherr, Karin

2012-01-01

Preliminary results indicated effectiveness of the online weight reduction program KiloCoach. The current study presents a large collection of user data and compares KiloCoach with other evaluated commercial weight loss programs. Furthermore, potential factors influencing the effectiveness of internet weight loss programs should be identified. 4,310 data sets of KiloCoach users were available, 3,150 of them were suitable for further analysis. 946 program users were considered completers (at least 60 days of continuous protocol). For comparison with other programs, different subsamples were drawn that matched to the inclusion criteria of reference studies. On average, KiloCoach overweight and obese completers lost 4.5 % of initial body weight. KiloCoach was as effective as the commercial program Weight Watchers® after 1 year (6.4% vs. 5.3% weight loss; p = 0.11) and 2 years (5.1% vs. 3.2% weight loss; p = 0.15). KiloCoach proved to be more effective than other online programs (Viktklubb, eDiets.com) as well as an in-person behavioral program, but less effective than Vtrim®, an online behavioral program providing intensive support. In comparison to reference programs, KiloCoach proved to be effective for weight reduction. The effect of online weight reduction programs seems to depend on methods and features applied.

Testing the interaction between analytical modules: an example with Roundup Ready® soybean line GTS 40-3-2

PubMed Central

2010-01-01

Background The modular approach to analysis of genetically modified organisms (GMOs) relies on the independence of the modules combined (i.e. DNA extraction and GM quantification). The validity of this assumption has to be proved on the basis of specific performance criteria. Results An experiment was conducted using, as a reference, the validated quantitative real-time polymerase chain reaction (PCR) module for detection of glyphosate-tolerant Roundup Ready® GM soybean (RRS). Different DNA extraction modules (CTAB, Wizard and Dellaporta), were used to extract DNA from different food/feed matrices (feed, biscuit and certified reference material [CRM 1%]) containing the target of the real-time PCR module used for validation. Purity and structural integrity (absence of inhibition) were used as basic criteria that a DNA extraction module must satisfy in order to provide suitable template DNA for quantitative real-time (RT) PCR-based GMO analysis. When performance criteria were applied (removal of non-compliant DNA extracts), the independence of GMO quantification from the extraction method and matrix was statistically proved, except in the case of Wizard applied to biscuit. A fuzzy logic-based procedure also confirmed the relatively poor performance of the Wizard/biscuit combination. Conclusions For RRS, this study recognises that modularity can be generally accepted, with the limitation of avoiding combining highly processed material (i.e. biscuit) with a magnetic-beads system (i.e. Wizard). PMID:20687918

Guidelines for the successful generation of protein–ligand complex crystals

PubMed Central

Müller, Ilka

2017-01-01

With continuous technical improvements at synchrotron facilities, data-collection rates have increased dramatically. This makes it possible to collect diffraction data for hundreds of protein–ligand complexes within a day, provided that a suitable crystal system is at hand. However, developing a suitable crystal system can prove challenging, exceeding the timescale of data collection by several orders of magnitude. Firstly, a useful crystallization construct of the protein of interest needs to be chosen and its expression and purification optimized, before screening for suitable crystallization and soaking conditions can start. This article reviews recent publications analysing large data sets of crystallization trials, with the aim of identifying factors that do or do not make a good crystallization construct, and gives guidance in the design of an expression construct. It provides an overview of common protein-expression systems, addresses how ligand binding can be both help and hindrance for protein purification, and describes ligand co-crystallization and soaking, with an emphasis on troubleshooting. PMID:28177304

Powdered activated carbons as effective phases for bar adsorptive micro-extraction (BAμE) to monitor levels of triazinic herbicides in environmental water matrices.

PubMed

Neng, N R; Mestre, A S; Carvalho, A P; Nogueira, J M F

2011-02-15

Bar adsorptive micro-extraction using three powdered activated carbons (ACs) as adsorbent phases followed by liquid desorption and high performance liquid chromatography with diode array detection (BAμE(ACs)-LD/HPLC-DAD), was developed to monitor triazinic herbicides (atrazine, simazine and terbutylazine) in environmental water matrices. ACs used present apparent surface areas around 1000 m(2) g(-1) with an important mesoporous volume and distinct surface chemistry characteristics (pH(PZC) ranging from 6.5 to 10.4). The textural and surface chemistry properties of the ACs adsorbent phases were correlated with the analytical data for a better understanding of the overall enrichment process. Assays performed on 10 mL water samples spiked at the 10.0 μg L(-1) levels under optimized experimental conditions yielded recoveries around 100% for the three herbicides under study. The analytical performance showed good precision (RSD<15.0%), convenient detection limits (≈0.1 μg L(-1)) and suitable linearity (1.0-12.0 μg L(-1)) with good correlation coefficients (r(2)>0.9914). By using the standard addition method, the application of the present method on real water matrices, such as surface water and wastewater, allowed very good performances at the trace level. The proposed methodology proved to be a suitable sorptive extraction alternative for the analysis of priority pollutants with polar characteristics, showing to be easy to implement, reliable, sensitive and requiring a low sample volume to monitor triazinic compounds in water matrices. Copyright © 2010 Elsevier B.V. All rights reserved.

Fast microwave-assisted acidolysis: a new biorefinery approach for the zero-waste utilisation of lignocellulosic biomass to produce high quality lignin and fermentable saccharides.

PubMed

Zhou, Long; Santomauro, Fabio; Fan, Jiajun; Macquarrie, Duncan; Clark, James; Chuck, Christopher J; Budarin, Vitaliy

2017-09-21

Generally, biorefineries convert lignocellulosic biomass into a range of biofuels and further value added chemicals. However, conventional biorefinery processes focus mainly on the cellulose and hemicellulose fractions and therefore produce only low quality lignin, which is commonly burnt to provide process heat. To make full use of the biomass, more attention needs to be focused on novel separation techniques, where high quality lignin can be isolated that is suitable for further valorisation into aromatic chemicals and fuel components. In this paper, three types of lignocellulosic biomass (softwood, hardwood and herbaceous biomass) were processed by microwave-assisted acidolysis to produce high quality lignin. The lignin from the softwood was isolated largely intact in the solid residue after acidolysis. For example, a 10 min microwave-assisted acidolysis treatment produced lignin with a purity of 93% and in a yield of 82%, which is superior to other conventional separation methods reported. Furthermore, py-GC/MS analysis proved that the isolated lignin retained the original structure of native lignin in the feedstock without severe chemical modification. This is a large advantage, and the purified lignin is suitable for further chemical processing. To assess the suitability of this methodology as part of a biorefinery system, the aqueous phase, produced after acidolysis of the softwood, was characterised and assessed for its suitability for fermentation. The broth contained some mono- and di-saccharides but mainly contained organic acids, oligosaccharides and furans. While this is unsuitable for S. cerevisiae and other common ethanol producing yeasts, two oleaginous yeasts with known inhibitor tolerances were selected: Cryptococcus curvatus and Metschnikowia pulcherrima. Both yeasts could grow on the broth, and demonstrated suitable catabolism of the oligosaccharides and inhibitors over 7 days. In addition, both yeasts were shown to be able to produce an oil with a similar composition to that of palm oil. This preliminary work demonstrates new protocols of microwave-assisted acidolysis and therefore offers an effective approach to produce high purity lignin and fermentable chemicals, which is a key step towards developing a zero-waste lignocellulosic biorefinery.

Manufacturing Methods and Technology Project Summary Reports

DTIC Science & Technology

1986-07-01

Yuma Proving Ground in January 1985. The ARBAT system provides a unique real-time computer capability to identify all critical flight...cheaper tnaii the existing radar system. This prototype is expected to save over ^1 million per year at Yuma Proving Grounds . TECOM is planning to...purchase 4 production ballistic radar systems to be installed at Yuma Proving Grounds , Dugway Proving Grounds , and Jefferson Proving Grounds at a

Practical aspects of genetic identification of hallucinogenic and other poisonous mushrooms for clinical and forensic purposes

PubMed Central

Kowalczyk, Marek; Sekuła, Andrzej; Mleczko, Piotr; Olszowy, Zofia; Kujawa, Anna; Zubek, Szymon; Kupiec, Tomasz

2015-01-01

Aim To assess the usefulness of a DNA-based method for identifying mushroom species for application in forensic laboratory practice. Methods Two hundred twenty-one samples of clinical forensic material (dried mushrooms, food remains, stomach contents, feces, etc) were analyzed. ITS2 region of nuclear ribosomal DNA (nrDNA) was sequenced and the sequences were compared with reference sequences collected from the National Center for Biotechnology Information gene bank (GenBank). Sporological identification of mushrooms was also performed for 57 samples of clinical material. Results Of 221 samples, positive sequencing results were obtained for 152 (69%). The highest percentage of positive results was obtained for samples of dried mushrooms (96%) and food remains (91%). Comparison with GenBank sequences enabled identification of all samples at least at the genus level. Most samples (90%) were identified at the level of species or a group of closely related species. Sporological and molecular identification were consistent at the level of species or genus for 30% of analyzed samples. Conclusion Molecular analysis identified a larger number of species than sporological method. It proved to be suitable for analysis of evidential material (dried hallucinogenic mushrooms) in forensic genetic laboratories as well as to complement classical methods in the analysis of clinical material. PMID:25727040

Aquatic environmental assessment of Lake Balaton in the light of physical-chemical water parameters.

PubMed

Sebestyén, Vitkor; Németh, József; Juzsakova, Tatjana; Domokos, Endre; Kovács, Zsófia; Rédey, Ákos

2017-11-01

One of the issues of the Hungarian Water Management Strategy is the improvement and upgrading of the water of Lake Balaton. The Water Framework Directive (WFD) specifies and sets forth the achievement of the good ecological status. However, the assessment of the water quality of the lake as a complex system requires a comprehensive monitoring and evaluation procedure. Measurements were carried out around the Lake Balaton at ten different locations/sites and 13 physical-chemical parameters were monitored at each measurement site.For the interpretation of the water chemistry parameters the Aquatic Environmental Assessment (AEA) method devised by authors was used for the water body of the Lake Balaton. The AEA method can be used for all types of the water bodies since it is flexible and using individual weighting procedure for the water chemistry parameters comprehensive information can be obtain. The AEA method was compared with existing EIA methods according to a predefined criterion system and proved to be the most suitable tool for evaluating the environmental impacts in our study.On the basis of the results it can be concluded that the status of the quality of studied area on the Lake Balaton can be categorized as proper quality (from the outcome of the ten measurement sites this conclusion was reached at seven sites).

Carbon analysis for inspecting carbonation of concrete using a TEA CO2 laser-induced plasma.

PubMed

Kagawa, Kiichiro; Idris, Nasrullah; Wada, Munehide; Kurniawan, Hendrik; Tsuyuki, Kenichiro; Miura, Satoru

2004-08-01

It has been demonstrated that a spectrochemical analysis of carbon using the laser plasma method can be successfully applied to inspect the carbonation of concrete by detecting carbon produced in aged concrete by a chemical reaction of Ca(OH)2 with CO2 gas in environmental air, turning into CaCO3, which induces degradation of the quality of building concrete. A comparative study has been made using a TEA CO2 laser (500-1000 mJ) and a Q-switched Nd-YAG laser (50-200 mJ) to search for the optimum conditions for carbon analysis, proving the advantage of the TEA CO2 laser for this purpose. Also, it was clarified that laser irradiation with suitable defocusing conditions is a crucial point for obtaining high sensitivity in the detection of carbon. Practical experiments on the inspection of carbonation were carried out using both a concrete sample that had been intentionally carbonated by exposure to high concentrations of CO2 gas and a naturally carbonated concrete sample. As a result, good coincidence was observed between the laser method and the ordinary method, which uses the chemical indicator phenolphthalein, implying that this laser technique is applicable as an in situ quantitative method of inspection for carbonation of concrete.

Comprehensive analysis of ß-lactam antibiotics including penicillins, cephalosporins, and carbapenems in poultry muscle using liquid chromatography coupled to tandem mass spectrometry.

PubMed

Berendsen, Bjorn J A; Gerritsen, Henk W; Wegh, Robin S; Lameris, Steven; van Sebille, Ralph; Stolker, Alida A M; Nielen, Michel W F

2013-09-01

A comprehensive method for the quantitative residue analysis of trace levels of 22 ß-lactam antibiotics, including penicillins, cephalosporins, and carbapenems, in poultry muscle by liquid chromatography in combination with tandem mass spectrometric detection is reported. The samples analyzed for ß-lactam residues are hydrolyzed using piperidine in order to improve compound stability and to include the total residue content of the cephalosporin ceftifour. The reaction procedure was optimized using a full experimental design. Following detailed isotope labeling, tandem mass spectrometry studies and exact mass measurements using high-resolution mass spectrometry reaction schemes could be proposed for all ß-lactams studied. The main reaction occurring is the hydrolysis of the ß-lactam ring under formation of the piperidine substituted amide. For some ß-lactams, multiple isobaric hydrolysis reaction products are obtained, in accordance with expectations, but this did not hamper quantitative analysis. The final method was fully validated as a quantitative confirmatory residue analysis method according to Commission Decision 2002/657/EC and showed satisfactory quantitative performance for all compounds with trueness between 80 and 110% and within-laboratory reproducibility below 22% at target level, except for biapenem. For biapenem, the method proved to be suitable for qualitative analysis only.

Individual and population pharmacokinetic compartment analysis: a graphic procedure for quantification of predictive performance.

PubMed

Eksborg, Staffan

2013-01-01

Pharmacokinetic studies are important for optimizing of drug dosing, but requires proper validation of the used pharmacokinetic procedures. However, simple and reliable statistical methods suitable for evaluation of the predictive performance of pharmacokinetic analysis are essentially lacking. The aim of the present study was to construct and evaluate a graphic procedure for quantification of predictive performance of individual and population pharmacokinetic compartment analysis. Original data from previously published pharmacokinetic compartment analyses after intravenous, oral, and epidural administration, and digitized data, obtained from published scatter plots of observed vs predicted drug concentrations from population pharmacokinetic studies using the NPEM algorithm and NONMEM computer program and Bayesian forecasting procedures, were used for estimating the predictive performance according to the proposed graphical method and by the method of Sheiner and Beal. The graphical plot proposed in the present paper proved to be a useful tool for evaluation of predictive performance of both individual and population compartment pharmacokinetic analysis. The proposed method is simple to use and gives valuable information concerning time- and concentration-dependent inaccuracies that might occur in individual and population pharmacokinetic compartment analysis. Predictive performance can be quantified by the fraction of concentration ratios within arbitrarily specified ranges, e.g. within the range 0.8-1.2.

Identifying the stored energy of a hyperelastic structure by using an attenuated Landweber method

NASA Astrophysics Data System (ADS)

Seydel, Julia; Schuster, Thomas

2017-12-01

We consider the nonlinear inverse problem of identifying the stored energy function of a hyperelastic material from full knowledge of the displacement field as well as from surface sensor measurements. The displacement field is represented as a solution of Cauchy’s equation of motion, which is a nonlinear elastic wave equation. Hyperelasticity means that the first Piola-Kirchhoff stress tensor is given as the gradient of the stored energy function. We assume that a dictionary of suitable functions is available. The aim is to recover the stored energy with respect to this dictionary. The considered inverse problem is of vital interest for the development of structural health monitoring systems which are constructed to detect defects in elastic materials from boundary measurements of the displacement field, since the stored energy encodes the mechanical properties of the underlying structure. In this article we develop a numerical solver using the attenuated Landweber method. We show that the parameter-to-solution map satisfies the local tangential cone condition. This result can be used to prove local convergence of the attenuated Landweber method in the case that the full displacement field is measured. In our numerical experiments we demonstrate how to construct an appropriate dictionary and show that our method is well suited to localize damages in various situations.

Weighted divergence correction scheme and its fast implementation

NASA Astrophysics Data System (ADS)

Wang, ChengYue; Gao, Qi; Wei, RunJie; Li, Tian; Wang, JinJun

2017-05-01

Forcing the experimental volumetric velocity fields to satisfy mass conversation principles has been proved beneficial for improving the quality of measured data. A number of correction methods including the divergence correction scheme (DCS) have been proposed to remove divergence errors from measurement velocity fields. For tomographic particle image velocimetry (TPIV) data, the measurement uncertainty for the velocity component along the light thickness direction is typically much larger than for the other two components. Such biased measurement errors would weaken the performance of traditional correction methods. The paper proposes a variant for the existing DCS by adding weighting coefficients to the three velocity components, named as the weighting DCS (WDCS). The generalized cross validation (GCV) method is employed to choose the suitable weighting coefficients. A fast algorithm for DCS or WDCS is developed, making the correction process significantly low-cost to implement. WDCS has strong advantages when correcting velocity components with biased noise levels. Numerical tests validate the accuracy and efficiency of the fast algorithm, the effectiveness of GCV method, and the advantages of WDCS. Lastly, DCS and WDCS are employed to process experimental velocity fields from the TPIV measurement of a turbulent boundary layer. This shows that WDCS achieves a better performance than DCS in improving some flow statistics.

Feature-Motivated Simplified Adaptive PCNN-Based Medical Image Fusion Algorithm in NSST Domain.

PubMed

Ganasala, Padma; Kumar, Vinod

2016-02-01

Multimodality medical image fusion plays a vital role in diagnosis, treatment planning, and follow-up studies of various diseases. It provides a composite image containing critical information of source images required for better localization and definition of different organs and lesions. In the state-of-the-art image fusion methods based on nonsubsampled shearlet transform (NSST) and pulse-coupled neural network (PCNN), authors have used normalized coefficient value to motivate the PCNN-processing both low-frequency (LF) and high-frequency (HF) sub-bands. This makes the fused image blurred and decreases its contrast. The main objective of this work is to design an image fusion method that gives the fused image with better contrast, more detail information, and suitable for clinical use. We propose a novel image fusion method utilizing feature-motivated adaptive PCNN in NSST domain for fusion of anatomical images. The basic PCNN model is simplified, and adaptive-linking strength is used. Different features are used to motivate the PCNN-processing LF and HF sub-bands. The proposed method is extended for fusion of functional image with an anatomical image in improved nonlinear intensity hue and saturation (INIHS) color model. Extensive fusion experiments have been performed on CT-MRI and SPECT-MRI datasets. Visual and quantitative analysis of experimental results proved that the proposed method provides satisfactory fusion outcome compared to other image fusion methods.

Postprocessing for character recognition using pattern features and linguistic information

NASA Astrophysics Data System (ADS)

Yoshikawa, Takatoshi; Okamoto, Masayosi; Horii, Hiroshi

1993-04-01

We propose a new method of post-processing for character recognition using pattern features and linguistic information. This method corrects errors in the recognition of handwritten Japanese sentences containing Kanji characters. This post-process method is characterized by having two types of character recognition. Improving the accuracy of the character recognition rate of Japanese characters is made difficult by the large number of characters, and the existence of characters with similar patterns. Therefore, it is not practical for a character recognition system to recognize all characters in detail. First, this post-processing method generates a candidate character table by recognizing the simplest features of characters. Then, it selects words corresponding to the character from the candidate character table by referring to a word and grammar dictionary before selecting suitable words. If the correct character is included in the candidate character table, this process can correct an error, however, if the character is not included, it cannot correct an error. Therefore, if this method can presume a character does not exist in a candidate character table by using linguistic information (word and grammar dictionary). It then can verify a presumed character by character recognition using complex features. When this method is applied to an online character recognition system, the accuracy of character recognition improves 93.5% to 94.7%. This proved to be the case when it was used for the editorials of a Japanese newspaper (Asahi Shinbun).

Electrowetting-based liquid lenses for endoscopy

NASA Astrophysics Data System (ADS)

Kuiper, S.

2011-03-01

In endoscopy there is a need for cameras with adjustable focus. In flexible and capsule endoscopes conventional focus systems are not suitable, because of restrictions in diameter and lens displacement range. In this paper it is shown that electrowetting-based variable-focus liquid lenses can provide a solution. A theoretical comparison is made between displacing and deforming lenses, and a demonstrator was built to prove the optical feasibility of focusing with liquid lenses in endoscopes.

Lipschitz stability for an inverse hyperbolic problem of determining two coefficients by a finite number of observations

NASA Astrophysics Data System (ADS)

Beilina, L.; Cristofol, M.; Li, S.; Yamamoto, M.

2018-01-01

We consider an inverse problem of reconstructing two spatially varying coefficients in an acoustic equation of hyperbolic type using interior data of solutions with suitable choices of initial condition. Using a Carleman estimate, we prove Lipschitz stability estimates which ensure unique reconstruction of both coefficients. Our theoretical results are justified by numerical studies on the reconstruction of two unknown coefficients using noisy backscattered data.

Porcine Intestinal Mast Cells. Evaluation of Different Fixatives for Histochemical Staining Techniques Considering Tissue Shrinkage

PubMed Central

Rieger, J.; Twardziok, S.; Huenigen, H.; Hirschberg, R.M.; Plendl, J.

2013-01-01

Staining of mast cells (MCs), including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF) has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkagedifferences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from data using different fixation techniques can only be compared if the respective studyimmanent shrinkage factor has been determined and quantification results are adjusted accordingly. PMID:24085270

Modeling shared resources with generalized synchronization within a Petri net bottom-up approach.

PubMed

Ferrarini, L; Trioni, M

1996-01-01

This paper proposes a simple and effective way to represent shared resources in manufacturing systems within a Petri net model previously developed. Such a model relies on the bottom-up and modular approach to synthesis and analysis. The designer may define elementary tasks and then connect them with one another with three kinds of connections: self-loops, inhibitor arcs and simple synchronizations. A theoretical framework has been established for the analysis of liveness and reversibility of such models. The generalized synchronization, here formalized, represents an extension of the simple synchronization, allowing the merging of suitable subnets among elementary tasks. It is proved that under suitable, but not restrictive, hypotheses the generalized synchronization may be substituted for a simple one, thus being compatible with all the developed theoretical body.

Evaluation of New Reference Genes in Papaya for Accurate Transcript Normalization under Different Experimental Conditions

PubMed Central

Chen, Weixin; Chen, Jianye; Lu, Wangjin; Chen, Lei; Fu, Danwen

2012-01-01

Real-time reverse transcription PCR (RT-qPCR) is a preferred method for rapid and accurate quantification of gene expression studies. Appropriate application of RT-qPCR requires accurate normalization though the use of reference genes. As no single reference gene is universally suitable for all experiments, thus reference gene(s) validation under different experimental conditions is crucial for RT-qPCR analysis. To date, only a few studies on reference genes have been done in other plants but none in papaya. In the present work, we selected 21 candidate reference genes, and evaluated their expression stability in 246 papaya fruit samples using three algorithms, geNorm, NormFinder and RefFinder. The samples consisted of 13 sets collected under different experimental conditions, including various tissues, different storage temperatures, different cultivars, developmental stages, postharvest ripening, modified atmosphere packaging, 1-methylcyclopropene (1-MCP) treatment, hot water treatment, biotic stress and hormone treatment. Our results demonstrated that expression stability varied greatly between reference genes and that different suitable reference gene(s) or combination of reference genes for normalization should be validated according to the experimental conditions. In general, the internal reference genes EIF (Eukaryotic initiation factor 4A), TBP1 (TATA binding protein 1) and TBP2 (TATA binding protein 2) genes had a good performance under most experimental conditions, whereas the most widely present used reference genes, ACTIN (Actin 2), 18S rRNA (18S ribosomal RNA) and GAPDH (Glyceraldehyde-3-phosphate dehydrogenase) were not suitable in many experimental conditions. In addition, two commonly used programs, geNorm and Normfinder, were proved sufficient for the validation. This work provides the first systematic analysis for the selection of superior reference genes for accurate transcript normalization in papaya under different experimental conditions. PMID:22952972

Investigation of Biodiesel Through Photopyroelectric and Dielectric-Constant Measurements as a Function of Temperature: Freezing/Melting Interval

NASA Astrophysics Data System (ADS)

Zanelato, E. B.; Machado, F. A. L.; Rangel, A. B.; Guimarães, A. O.; Vargas, H.; da Silva, E. C.; Mansanares, A. M.

2015-06-01

Biodiesel is a promising option for alternative fuels since it derives from natural and renewable materials; it is biodegradable and less polluting than fossil fuels. A gradual replacement of diesel by biodiesel has been adopted by many countries, making necessary the investigation of the physical properties of biodiesel and of its mixture in diesel. Photothermal techniques, specifically the photopyroelectric technique (PPE), have proved to be suitable in the characterization of biodiesel and of its precursor oils, as well as of the biodiesel/diesel mixtures. In this paper, we investigate thermal and electrical properties of animal fat-based biodiesel as a function of temperature, aiming to characterize the freezing/melting interval and the changes in the physical properties from the solid to the liquid phase. The samples were prepared using the transesterification method, by the ethylic route. Optical transmittance experiments were carried out in order to confirm the phase transition interval. Solid and liquid phases present distinct thermal diffusivities and conductivities, as well as dielectric constants. The PPE signal amplitude is governed by the changes in the thermal diffusivity/conductivity. As a consequence, the amplitude of the signal becomes like a step function, which is smoothed and sometimes delayed by the nucleation processes during cooling. A similar behavior is found in the dielectric constant data, which is higher in the liquid phase since the molecules have a higher degree of freedom. Both methods (PPE/dielectric constant) proved to be useful in the characterization of the freezing/melting interval, as well as to establish the distinction in the physical properties of solid and liquid phases. The methodology allowed a discussion of the cloud point and the pour point of the samples in the temperature variation interval.

Rapid real-time PCR methods to distinguish Salmonella Enteritidis wildtype field isolates from vaccine strains Salmovac SE/Gallivac SE and AviPro SALMONELLA VAC E.

PubMed

Maurischat, Sven; Szabo, Istvan; Baumann, Beatrice; Malorny, Burkhard

2015-05-01

Salmonella enterica serovar Enteritidis is a major non-typhoid Salmonella serovar causing human salmonellosis mainly associated with the consumption of poultry and products thereof. To reduce infections in poultry, S. Enteritidis live vaccine strains AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE have been licensed and used in several countries worldwide. To definitively diagnose a S. Enteritidis contamination in vaccinated herds a reliable and fast method for the differentiation between vaccine and wildtype field isolates is required. In this study, we developed and validated real-time PCR (qPCR) assays to distinguish those variants genetically. Suitable target sequences were identified by whole genome sequencing (WGS) using the Illumina MiSeq system. SNP regions in kdpA and nhaA proved to be most useful for differentiation of AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE, respectively, from wildtype strains. For each vaccine strain one TaqMan-qPCR assay and one alternative approach using High Resolution Melting (HRM) analysis was designed. All 30 Salmovac SE and 7 AviPro SALMONELLA VAC E vaccine strain reisolates tested were correctly identified by both approaches (100% inclusivity). Furthermore, all 137 (TaqMan) and 97 (HRM) Salmonella non-vaccine and related Enterobacteriaceae strains tested were excluded (100% exclusivity). The analytical detection limits were determined to be approx. 10(2) genome copies/reaction for the TaqMan and 10(4) genome copies/reaction for the HRM approach. The real-time PCR assays proved to be a reliable and fast alternative to the cultural vaccine strain identification tests helping decision makers in control measurements to take action within a shorter period of time. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of culture media for the recovery of airborne yeast in wineries.

PubMed

Ocón, E; Garijo, P; Santamaría, P; López, R; Olarte, C; Gutiérrez, A R; Sanz, S

2013-09-01

The direct air sampling impaction method on agar was evaluated using aerobiocollectors for the recovery of yeasts present in the winery air. Three culture media with different composition and specificity were studied. In addition, a resuscitation phase was included before the culture in the specificity medium [in the case of the Dekkera-Brettanomyces Differential Medium (DBDM) medium]. Sampling was conducted at different times of the year and in different parts of the wineries, which were different in age and design. Both the Chloramphenicol Glucose Agar (CGA) and Agar Lysine AL media recovered yeasts from the air without any prior resuscitation phase. CGA was able to recover a higher number of colony-forming units of yeasts than the other media. Consequently, to estimate the number of yeasts present in winery air, the best choice of medium would be CGA. The AL medium permitted the growth of the greatest range of genera and species. If the aim is to study the diversity of yeasts present in the air, the most suitable medium is AL. Neither CGA nor AL proved suitable for recovering yeasts of the Brettanomyces genus. The DBDM medium was the only one which provided sufficient specificity for their recovery and identification from the air, although their special characteristics made a prior protocol of resuscitation necessary. © 2013 The Society for Applied Microbiology.

Raman Spectroscopic Detection for Simulants of Chemical Warfare Agents Using a Spatial Heterodyne Spectrometer.

PubMed

Hu, Guangxiao; Xiong, Wei; Luo, Haiyan; Shi, Hailiang; Li, Zhiwei; Shen, Jing; Fang, Xuejing; Xu, Biao; Zhang, Jicheng

2018-01-01

Raman spectroscopic detection is one of the suitable methods for the detection of chemical warfare agents (CWAs) and simulants. Since the 1980s, many researchers have been dedicated to the research of chemical characteristic of CWAs and simulants and instrumental improvement for their analysis and detection. The spatial heterodyne Raman spectrometer (SHRS) is a new developing instrument for Raman detection that appeared in 2011. It is already well-known that SHRS has the characteristics of high spectral resolution, a large field-of-view, and high throughput. Thus, it is inherently suitable for the analysis and detection of these toxic chemicals and simulants. The in situ and standoff detection of some typical simulants of CWAs, such as dimethyl methylphosphonate (DMMP), diisopropyl methylphosphonate (DIMP), triethylphosphate (TEP), diethyl malonate (DEM), methyl salicylate (MES), 2-chloroethyl ethyl sulfide (CEES), and malathion, were tried. The achieved results show that SHRS does have the ability of in situ analysis or standoff detection for simulants of CWAs. When the laser power was set to as low as 26 mW, the SHRS still has a signal-to-noise ratio higher than 5 in in situ detection. The standoff Raman spectra detection of CWAs simulants was realized at a distance of 11 m. The potential feasibility of standoff detection of SHRS for CWAs simulants has been proved.

Zirconia in dental implantology: A review

PubMed Central

Apratim, Abhishek; Eachempati, Prashanti; Krishnappa Salian, Kiran Kumar; Singh, Vijendra; Chhabra, Saurabh; Shah, Sanket

2015-01-01

Background: Titanium has been the most popular material of choice for dental implantology over the past few decades. Its properties have been found to be most suitable for the success of implant treatment. But recently, zirconia is slowly emerging as one of the materials which might replace the gold standard of dental implant, i.e., titanium. Materials and Methods: Literature was searched to retrieve information about zirconia dental implant and studies were critically analyzed. PubMed database was searched for information about zirconia dental implant regarding mechanical properties, osseointegration, surface roughness, biocompatibility, and soft tissue health around it. The literature search was limited to English language articles published from 1975 to 2015. Results: A total of 45 papers met the inclusion criteria for this review, among the relevant search in the database. Conclusion: Literature search showed that some of the properties of zirconia seem to be suitable for making it an ideal dental implant, such as biocompatibility, osseointegration, favourable soft tissue response and aesthetics due to light transmission and its color. At the same time, some studies also point out its drawbacks. It was also found that most of the studies on zirconia dental implants are short-term studies and there is a need for more long-term clinical trials to prove that zirconia is worth enough to replace titanium as a biomaterial in dental implantology. PMID:26236672

Radar-raingauge data combination techniques: a revision and analysis of their suitability for urban hydrology.

PubMed

Wang, Li-Pen; Ochoa-Rodríguez, Susana; Simões, Nuno Eduardo; Onof, Christian; Maksimović, Cedo

2013-01-01

The applicability of the operational radar and raingauge networks for urban hydrology is insufficient. Radar rainfall estimates provide a good description of the spatiotemporal variability of rainfall; however, their accuracy is in general insufficient. It is therefore necessary to adjust radar measurements using raingauge data, which provide accurate point rainfall information. Several gauge-based radar rainfall adjustment techniques have been developed and mainly applied at coarser spatial and temporal scales; however, their suitability for small-scale urban hydrology is seldom explored. In this paper a review of gauge-based adjustment techniques is first provided. After that, two techniques, respectively based upon the ideas of mean bias reduction and error variance minimisation, were selected and tested using as case study an urban catchment (∼8.65 km(2)) in North-East London. The radar rainfall estimates of four historical events (2010-2012) were adjusted using in situ raingauge estimates and the adjusted rainfall fields were applied to the hydraulic model of the study area. The results show that both techniques can effectively reduce mean bias; however, the technique based upon error variance minimisation can in general better reproduce the spatial and temporal variability of rainfall, which proved to have a significant impact on the subsequent hydraulic outputs. This suggests that error variance minimisation based methods may be more appropriate for urban-scale hydrological applications.

Clustering methods for the optimization of atomic cluster structure

NASA Astrophysics Data System (ADS)

Bagattini, Francesco; Schoen, Fabio; Tigli, Luca

2018-04-01

In this paper, we propose a revised global optimization method and apply it to large scale cluster conformation problems. In the 1990s, the so-called clustering methods were considered among the most efficient general purpose global optimization techniques; however, their usage has quickly declined in recent years, mainly due to the inherent difficulties of clustering approaches in large dimensional spaces. Inspired from the machine learning literature, we redesigned clustering methods in order to deal with molecular structures in a reduced feature space. Our aim is to show that by suitably choosing a good set of geometrical features coupled with a very efficient descent method, an effective optimization tool is obtained which is capable of finding, with a very high success rate, all known putative optima for medium size clusters without any prior information, both for Lennard-Jones and Morse potentials. The main result is that, beyond being a reliable approach, the proposed method, based on the idea of starting a computationally expensive deep local search only when it seems worth doing so, is capable of saving a huge amount of searches with respect to an analogous algorithm which does not employ a clustering phase. In this paper, we are not claiming the superiority of the proposed method compared to specific, refined, state-of-the-art procedures, but rather indicating a quite straightforward way to save local searches by means of a clustering scheme working in a reduced variable space, which might prove useful when included in many modern methods.

Analytical performances of a new enzymatic assay for hemoglobin A1c.

PubMed

Jaisson, Stéphane; Desmons, Aurore; Renard, Benoît; Chevelle, Benjamin; Leroy, Nathalie; Gillery, Philippe

2014-07-01

HbA1c is considered the gold standard for the follow-up of diabetic patients and a new diagnostic tool for diabetes mellitus, which implies the availability of reliable assay methods. We have evaluated a new assay developed by Abbott Laboratories, based on the enzymatic quantification of HbA1c by a fructosyl dipeptide oxidase using Architect analyzers. Precision, linearity, correlation with a HPLC method, accuracy and potential impact interferences on HbA1c measurement have been evaluated. Intra-day and between-day CVs were lower than 1.2% and linearity was excellent from 19 mmol/mol (3.9%) to 163 mmol/mol (17.1%). The results were well correlated with those obtained by the HPLC (Variant II device, kit NU - BioRad): HbA1c [Architect, mmol/mol]=0.986×HbA1c [Variant II, mmol/mol]+0.713 (r=0.998, n=109). This method provided consistent results with IFCC titrated quality control samples. Classical interferences in HbA1c assays (i.e. labile HbA1c, carbamylated hemoglobin, triglycerides or bilirubin) did not have an impact on HbA1c quantification by this method. This new enzymatic assay proved to be a robust and reliable method for HbA1c measurement suitable for routine practice in clinical chemistry laboratories. Copyright © 2014 Elsevier B.V. All rights reserved.

A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals

PubMed Central

La Barbera, Giorgia; Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Montone, Carmela Maria; Zenezini Chiozzi, Riccardo; Laganà, Aldo

2017-01-01

Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE), a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high–performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes. PMID:28430148

A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals.

PubMed

Barbera, Giorgia La; Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Montone, Carmela Maria; Chiozzi, Riccardo Zenezini; Laganà, Aldo

2017-04-21

Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE), a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high-performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

A study of method robustness for arsenic speciation in drinking water samples by anion exchange HPLC-ICP-MS.

PubMed

Day, Jason A; Montes-Bayón, María; Vonderheide, Anne P; Caruso, Joseph A

2002-08-01

Regulating arsenic species in drinking waters is a reasonable objective, since the various species have different toxicological impacts. However, developing robust and sensitive speciation methods is mandatory prior to any such regulations. Numerous arsenic speciation publications exist, but the question of robustness or ruggedness for a regulatory method has not been fully explored. The present work illustrates the use of anion exchange chromatography coupled to ICP-MS with a commercially available "speciation kit" option. The mobile phase containing 2 mM NaH(2)PO(4) and 0.2 mM EDTA at pH 6 allowed adequate separation of four As species (As(III), As(V), MMAA, DMAA) in less than 10 min. The analytical performance characteristics studied, including method detection limits (lower than 100 ng L(-1) for all the species evaluated), proved the suitability of the method to fulfill the current regulation. Other parameters evaluated such as laboratory fortified blanks, spiked recoveries, and reproducibility over a certain period of time produced adequate results. The samples analyzed were taken from water utilities in different areas of the United States and were provided by the U.S. EPA. The data suggests the speciation setup performs to U.S. EPA specifications but sample treatment and chemistry are also important factors for achieving good recoveries for samples spiked with As(III) as arsenite and As(V) as arsenate.

Suitability of peracetic acid for sterilization of media for mycoplasma cultures.

PubMed Central

Wutzler, P; Sprössig, M; Peterseim, H

1975-01-01

The utility of peracetic acid for sterilization of serum and yeast extract additions to mycoplasma medium was studied by culturing six Mycoplasma species. Culture media containing additions that had been sterilized with peracetic acid proved to be as good as filtered components. The use of 0.05 to 0.1% peracetic acid is recommended to sterilize the serum and yeast extract additions since savings in time and equipment can be accomplished. PMID:1100656

Development of Organic Nonlinear Optical Materials

DTIC Science & Technology

1992-10-22

been used by Casstevens, et al, to analyze DFWM results on Langmuir - Blodgett films of SiPc derivatives and evaporated films of metal free phthalocyanine...of poly (THF) (MW = 650 g/mol), a soluble branched polymer was produced. The reaction was carried out either neat, or in THF without addition of any...substantially and poly (THF) proved suitable. The resultant polymer was soluble with a lower Tg due to plasticizing effects. A major cause of concern in this work

Invasive Saccharomyces cerevisiae infection: a friend turning foe?

PubMed

Pillai, Unnikrishnan; Devasahayam, Joe; Kurup, Aparna Narayana; Lacasse, Alexandre

2014-11-01

We report a very rare case of acute pyelonephritis in a 51-year-old female with a history of chronic kidney disease (CKD) and diabetes caused by a normally benign and a well-known human commensal organism, Saccharomyces cerevisiae that is very often prescribed as a probiotic in modern medical practice. The causal role of S. cerevisiae was confirmed by its isolation in blood, urine, stool as well as vaginal swabs thus proving its virulent nature in suitable situations.

Integrable structure in discrete shell membrane theory

PubMed Central

Schief, W. K.

2014-01-01

We present natural discrete analogues of two integrable classes of shell membranes. By construction, these discrete shell membranes are in equilibrium with respect to suitably chosen internal stresses and external forces. The integrability of the underlying equilibrium equations is proved by relating the geometry of the discrete shell membranes to discrete O surface theory. We establish connections with generalized barycentric coordinates and nine-point centres and identify a discrete version of the classical Gauss equation of surface theory. PMID:24808755

Integrable structure in discrete shell membrane theory.

PubMed

Schief, W K

2014-05-08

We present natural discrete analogues of two integrable classes of shell membranes. By construction, these discrete shell membranes are in equilibrium with respect to suitably chosen internal stresses and external forces. The integrability of the underlying equilibrium equations is proved by relating the geometry of the discrete shell membranes to discrete O surface theory. We establish connections with generalized barycentric coordinates and nine-point centres and identify a discrete version of the classical Gauss equation of surface theory.

The cosmological constant and the energy of gravitational radiation

NASA Astrophysics Data System (ADS)

Chruściel, Piotr T.; Ifsits, Lukas

2016-06-01

We propose a definition of mass for characteristic hypersurfaces in asymptotically vacuum space-times with nonvanishing cosmological constant Λ ∈R* , generalizing the definition of Trautman and Bondi for Λ =0 . We show that our definition reduces to some standard definitions in several situations. We establish a balance formula linking the characteristic mass and a suitably defined renormalized volume of the null hypersurface, generalizing the positivity identity proved by Chruściel and Paetz when Λ =0 .

Army Advanced Concept Technology Demonstrations - The Inside Story

DTIC Science & Technology

1997-08-01

has M.S. sors suitable for field use are expected to be * What are the costs vs . benefits and/or and Ph.D. degrees in applied math- available in...scales and in different Proving languages. Implementation Forces (IFOR) Ground. established a Mine Action Center ( MAC ) to deal with the mine incidents and...minefield data problems. Initially, the data had to be manually tracked and posted. Working with personnel in the MAC , the ACTF sponsored work leading

Nonwoven-Based Gelatin/Polycaprolactone Membrane Proves Suitability in a Preclinical Assessment for Treatment of Soft Tissue Defects

PubMed Central

Schulz, Simon; Angarano, Marco; Fabritius, Martin; Mülhaupt, Rolf; Dard, Michel; Obrecht, Marcel; Tomakidi, Pascal

2014-01-01

Standard preclinical assessments in vitro often have limitations regarding their transferability to human beings, mainly evoked by their nonhuman and tissue-different/nontissue-specific source. Here, we aimed at employing tissue-authentic simple and complex interactive fibroblast-epithelial cell systems and their in vivo-relevant biomarkers for preclinical in vitro assessment of nonwoven-based gelatin/polycaprolactone membranes (NBMs) for treatment of soft tissue defects. NBMs were composed of electrospun gelatin and polycaprolactone nanofiber nonwovens. Scanning electron microscopy in conjunction with actin/focal contact integrin fluorescence revealed successful adhesion and proper morphogenesis of keratinocytes and fibroblasts, along with cells' derived extracellular matrix deposits. The “feel-good factor” of cells under study on the NBM was substantiated by forming a confluent connective tissue entity, which was concomitant with a stratified epithelial equivalent. Immunohistochemistry proved tissue authenticity over time by abundance of the biomarker vimentin in the connective tissue entity, and chronological increase of keratins KRT1/10 and involucrin expression in epithelial equivalents. Suitability of the novel NBM as wound dressing was evidenced by an almost completion of epithelial wound closure in a pilot mini-pig study, after a surgical intervention-caused gingival dehiscence. In summary, preclinical assessment by tissue-authentic cell systems and the animal pilot study revealed the NBM as an encouraging therapeutic medical device for prospective clinical applications. PMID:24494668

Strongly nonlinear waves in locally resonant granular chains

DOE PAGES

Liu, Lifeng; James, Guillaume; Kevrekidis, Panayotis; ...

2016-09-23

In this paper, we explore a recently proposed locally resonant granular system bearing harmonic internal resonators in a chain of beads interacting via Hertzian elastic contacts. In this system, we propose the existence of two types of configurations: (a) small-amplitude periodic traveling waves and (b) dark-breather solutions, i.e. exponentially localized, time-periodic states mounted on top of a non-vanishing background. A remarkable feature distinguishing our results from other settings where dark breathers are observed is the complete absence of precompression in the system, i.e. the absence of a linear spectral band. We also identify conditions under which the system admits long-livedmore » bright breather solutions. Our results are obtained by means of an asymptotic reduction to a suitably modified version of the so-called discrete p-Schrödinger (DpS) equation, which is established as controllably approximating the solutions of the original system for large but finite times (under suitable assumptions on the solution amplitude and the resonator mass). The findings are also corroborated by detailed numerical computations. Long-lived bright breathers are proved to exist over long but finite times, after which numerical simulations indicate that the breathers disintegrate. Finally, in line with these results, we prove that the only exact time-periodic bright breathers consist of trivial linear oscillations, without contact interactions between discrete elements.« less

Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

DOEpatents

Bond, Tiziana C.; Miles, Robin; Davidson, James C.; Liu, Gang Logan

2014-07-22

Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

DOEpatents

Bond, Tiziana C.; Miles, Robin; Davidson, James C.; Liu, Gang Logan

2015-07-14

Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

DOEpatents

Bond, Tiziana C; Miles, Robin; Davidson, James; Liu, Gang Logan

2015-11-03

Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

Low angle light scattering analysis: a novel quantitative method for functional characterization of human and murine platelet receptors.

PubMed

Mindukshev, Igor; Gambaryan, Stepan; Kehrer, Linda; Schuetz, Claudia; Kobsar, Anna; Rukoyatkina, Natalia; Nikolaev, Viacheslav O; Krivchenko, Alexander; Watson, Steve P; Walter, Ulrich; Geiger, Joerg

2012-07-01

Determinations of platelet receptor functions are indispensable diagnostic indicators of cardiovascular and hemostatic diseases including hereditary and acquired receptor defects and receptor responses to drugs. However, presently available techniques for assessing platelet function have some disadvantages, such as low sensitivity and the requirement of large sample sizes and unphysiologically high agonist concentrations. Our goal was to develop and initially characterize a new technique designed to quantitatively analyze platelet receptor activation and platelet function on the basis of measuring changes in low angle light scattering. We developed a novel technique based on low angle light scattering registering changes in light scattering at a range of different angles in platelet suspensions during activation. The method proved to be highly sensitive for simultaneous real time detection of changes in size and shape of platelets during activation. Unlike commonly-used methods, the light scattering method could detect platelet shape change and aggregation in response to nanomolar concentrations of extracellular nucleotides. Furthermore, our results demonstrate that the advantages of the light scattering method make it a choice method for platelet receptor monitoring and for investigation of both murine and human platelets in disease models. Our data demonstrate the suitability and superiority of this new low angle light scattering method for comprehensive analyses of platelet receptors and functions. This highly sensitive, quantitative, and online detection of essential physiological, pathophysiological and pharmacological-response properties of human and mouse platelets is a significant improvement over conventional techniques.

Approximate Model Checking of PCTL Involving Unbounded Path Properties

NASA Astrophysics Data System (ADS)

Basu, Samik; Ghosh, Arka P.; He, Ru

We study the problem of applying statistical methods for approximate model checking of probabilistic systems against properties encoded as PCTL formulas. Such approximate methods have been proposed primarily to deal with state-space explosion that makes the exact model checking by numerical methods practically infeasible for large systems. However, the existing statistical methods either consider a restricted subset of PCTL, specifically, the subset that can only express bounded until properties; or rely on user-specified finite bound on the sample path length. We propose a new method that does not have such restrictions and can be effectively used to reason about unbounded until properties. We approximate probabilistic characteristics of an unbounded until property by that of a bounded until property for a suitably chosen value of the bound. In essence, our method is a two-phase process: (a) the first phase is concerned with identifying the bound k 0; (b) the second phase computes the probability of satisfying the k 0-bounded until property as an estimate for the probability of satisfying the corresponding unbounded until property. In both phases, it is sufficient to verify bounded until properties which can be effectively done using existing statistical techniques. We prove the correctness of our technique and present its prototype implementations. We empirically show the practical applicability of our method by considering different case studies including a simple infinite-state model, and large finite-state models such as IPv4 zeroconf protocol and dining philosopher protocol modeled as Discrete Time Markov chains.

Metrology of vibration measurements by laser techniques

NASA Astrophysics Data System (ADS)

von Martens, Hans-Jürgen

2008-06-01

Metrology as the art of careful measurement has been understood as uniform methodology for measurements in natural sciences, covering methods for the consistent assessment of experimental data and a corpus of rules regulating application in technology and in trade and industry. The knowledge, methods and tools available for precision measurements can be exploited for measurements at any level of uncertainty in any field of science and technology. A metrological approach to the preparation, execution and evaluation (including expression of uncertainty) of measurements of translational and rotational motion quantities using laser interferometer methods and techniques will be presented. The realization and dissemination of the SI units of motion quantities (vibration and shock) have been based on laser interferometer methods specified in international documentary standards. New and upgraded ISO standards are reviewed with respect to their suitability for ensuring traceable vibration measurements and calibrations in an extended frequency range of 0.4 Hz to higher than 100 kHz. Using adequate vibration exciters to generate sufficient displacement or velocity amplitudes, the upper frequency limits of the laser interferometer methods specified in ISO 16063-11 for frequencies <= 10 kHz can be expanded to 100 kHz and beyond. A comparison of different methods simultaneously used for vibration measurements at 100 kHz will be demonstrated. A statistical analysis of numerous experimental results proves the highest accuracy achievable currently in vibration measurements by specific laser methods, techniques and procedures (i.e. measurement uncertainty 0.05 % at frequencies <= 10 kHz, <= 1 % up to 100 kHz).

Analytical Models of Exoplanetary Atmospheres. IV. Improved Two-stream Radiative Transfer for the Treatment of Aerosols

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

Heng, Kevin; Kitzmann, Daniel, E-mail: kevin.heng@csh.unibe.ch, E-mail: daniel.kitzmann@csh.unibe.ch

We present a novel generalization of the two-stream method of radiative transfer, which allows for the accurate treatment of radiative transfer in the presence of strong infrared scattering by aerosols. We prove that this generalization involves only a simple modification of the coupling coefficients and transmission functions in the hemispheric two-stream method. This modification originates from allowing the ratio of the first Eddington coefficients to depart from unity. At the heart of the method is the fact that this ratio may be computed once and for all over the entire range of values of the single-scattering albedo and scattering asymmetrymore » factor. We benchmark our improved two-stream method by calculating the fraction of flux reflected by a single atmospheric layer (the reflectivity) and comparing these calculations to those performed using a 32-stream discrete-ordinates method. We further compare our improved two-stream method to the two-stream source function (16 streams) and delta-Eddington methods, demonstrating that it is often more accurate at the order-of-magnitude level. Finally, we illustrate its accuracy using a toy model of the early Martian atmosphere hosting a cloud layer composed of carbon dioxide ice particles. The simplicity of implementation and accuracy of our improved two-stream method renders it suitable for implementation in three-dimensional general circulation models. In other words, our improved two-stream method has the ease of implementation of a standard two-stream method, but the accuracy of a 32-stream method.« less

A validated stability-indicating LC method for the separation of enantiomer and potential impurities of Linezolid using polar organic mode.

PubMed

Satyanarayana Raju, T; Vishweshwari Kutty, O; Ganesh, V; Yadagiri Swamy, P

2012-08-01

Although a number of methods are available for evaluating Linezolid and its possible impurities, a common method for separation if its potential impurities, degradants and enantiomer in a single method with good efficiency remain unavailable. With the objective of developing an advanced method with shorter runtimes, a simple, precise, accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. This method is capable of separating all the related substances of Linezolid along with the chiral impurity. This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product. The method was developed using Chiralpak IA (250 mm×4.6 mm, 5 μm) column. A mixture of acetonitrile, ethanol, n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v) ratio was used as a mobile phase. The eluted compounds were monitored at 254 nm. Linezolid was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, limit of detection, limit of quantification, precision, linearity, accuracy, robustness and system suitability.

Emotionalized learning experiences: Tapping into the affective domain.

PubMed

Green, Zane Asher; Batool, Sadia

2017-06-01

The experimental study was undertaken to examine the effect of emotionalized learning experiences on the academic achievement of students at Preston University. The major objectives of the study were to identify the effect of teaching methods on students' academic achievement and to evaluate the relationship between affective learning conditions and students' academic achievement. Based on four intact semesters, the population of the study comprised 140 students from the Bachelors of Business Administration Program. The whole population was considered as the sample. The control group (28 students) was taught through the interactive lecture method, whereas, the experimental group 1 (35 students), experimental group 2 (46 students) and experimental group 3 (31 students) were taught through the activity method, reflective learning method and cooperative learning method respectively. Results indicated a significant difference between the pretest and posttest scores obtained in the achievement test as a result of the effect of teaching methods used for offering the emotionalized learning experiences. There was also a significant relationship between affective leaning conditions and students' academic achievement. Furthermore, it was found that students' academic achievement in the affective domain was highest with regard to workshops 1, 2 and 3. It was concluded that the emotionalized learning experiences offered to the students via the four teaching methods helped students in enhancing their knowledge, changing their attitudes and developing their skills with regard to living a happy, healthy and meaningful life. However, the reflective learning method proved to be the most suitable followed by the interactive lecture method, the cooperative learning method and the activity method. Copyright © 2017 Elsevier Ltd. All rights reserved.

Loudspeakers: Modeling and control

NASA Astrophysics Data System (ADS)

Al-Ali, Khalid Mohammad

This thesis documented a comprehensive study of loudspeaker modeling and control. A lumped-parameter model for a voice-coil loudspeaker in a vented enclosure was presented that derived from a consideration of physical principles. In addition, a low-frequency (20 Hz to 100 Hz), feedback control method designed to improve the nonlinear performance of the loudspeaker and a suitable performance measure for use in design and evaluation were proposed. Data from experiments performed on a variety of actual loudspeakers confirmed the practicality of the theory developed in this work. The lumped-parameter loudspeaker model, although simple, captured much of the nonlinear behavior of the loudspeaker. In addition, the model formulation allowed a straightforward application of modern control system methods and lent itself well to modern parametric identification techniques. The nonlinear performance of the loudspeaker system was evaluated using a suitable distortion measure that was proposed and compared with other distortion measures currently used in practice. Furthermore, the linearizing effect of feedback using a linear controller (both static and dynamic) was studied on a class of nonlinear systems. The results illustrated that the distortion reduction was potentially significant and a useful upper bound on the closed-loop distortion was found based on the sensitivity function of the system's linearization. A feedback scheme based on robust control theory was chosen for application to the loudspeaker system. Using the pressure output of the loudspeaker system for feedback, the technique offered significant advantages over those previously attempted. Illustrative examples were presented that proved the applicability of the theory developed in this dissertation to a variety of loudspeaker systems. The examples included a vented loudspeaker model and actual loudspeakers enclosed in both vented and sealed configurations. In each example, predictable and measurable distortion reduction at the output of the closed-loop system was recorded.

Mechanically robust silver coatings prepared by electroless plating on thermoplastic polyurethane

NASA Astrophysics Data System (ADS)

Vasconcelos, B.; Vediappan, K.; Oliveira, J. C.; Fonseca, C.

2018-06-01

A simple and low-cost surface functionalization method is proposed to activate a thermoplastic polyurethane (TPU) for the electroless deposition of a silver coating with excellent adhesion and low resistivity. The TPU surface functionalization was performed in solution and consisted in forming a physical interpenetrating network at the TPU surface, involving TPU and polyvinylpyrrolidone (PVP), a polymer displaying a strong affinity for metals. The presence of PVP on the TPU surface and its stability in aqueous solution were assessed by ATR-FTIR and contact angle measurements as a function of the PVP concentration and treatment time. A modified Tollens solution was used to grow a silver film on the TPU substrate, by using the electroless plating method. Compact silver films with an average thickness of 12.5 μm and a resistivity of 8.57 mΩ·cm were obtained for a 24 h plating time. The adhesion strength of the silver film proved to be higher than 8.5 N/cm. The resistance to fatigue of the silver films was studied by performing series of compression/stretching tests (150 cycles). It was concluded that the films kept low resistance values, although displaying a higher sensitivity to compression than to stretching. Furthermore, the films keep a good conductivity for strains up to 400%. The excellent electrical and mechanical properties of the films make them suitable candidates for the coating of multipin dry bioelectrodes. Owing to the high affinity of many metals for PVP, this activation technique has the potential to be extended to the deposition of other metals and other polymers as well, provided a suitable solvent is used.

Development of a Coordinate Transformation method for direct georeferencing in map projection frames

NASA Astrophysics Data System (ADS)

Zhao, Haitao; Zhang, Bing; Wu, Changshan; Zuo, Zhengli; Chen, Zhengchao

2013-03-01

This paper develops a novel Coordinate Transformation method (CT-method), with which the orientation angles (roll, pitch, heading) of the local tangent frame of the GPS/INS system are transformed into those (omega, phi, kappa) of the map projection frame for direct georeferencing (DG). Especially, the orientation angles in the map projection frame were derived from a sequence of coordinate transformations. The effectiveness of orientation angles transformation was verified through comparing with DG results obtained from conventional methods (Legat method and POSPac method) using empirical data. Moreover, the CT-method was also validated with simulated data. One advantage of the proposed method is that the orientation angles can be acquired simultaneously while calculating position elements of exterior orientation (EO) parameters and auxiliary points coordinates by coordinate transformation. These three methods were demonstrated and compared using empirical data. Empirical results show that the CT-method is both as sound and effective as Legat method. Compared with POSPac method, the CT-method is more suitable for calculating EO parameters for DG in map projection frames. DG accuracy of the CT-method and Legat method are at the same level. DG results of all these three methods have systematic errors in height due to inconsistent length projection distortion in the vertical and horizontal components, and these errors can be significantly reduced using the EO height correction technique in Legat's approach. Similar to the results obtained with empirical data, the effectiveness of the CT-method was also proved with simulated data. POSPac method: The method is presented by Applanix POSPac software technical note (Hutton and Savina, 1997). It is implemented in the POSEO module of POSPac software.

A simple LC-MS method for determination of cyasterone in rat plasma: application to a pilot pharmacokinetic study.

PubMed

Li, Fuqiang; Li, Guangyu; Zhao, Jinsong; Xiao, Jun; Liu, Zaoxia; Su, Guanfang

2016-06-01

A simple, specific, and sensitive liquid chromatography-mass spectrometry (LC-MS) method for determination of cyasterone in rat plasma was developed in our laboratory. Cucurbitacin B was used as an internal standard (IS). After protein precipitation with twofold volume of acetonitrile, the analyte and IS were separated on a Luna C18 column (100 × 4.6 mm, i.d., 3.0 µm; Phenomenex) by isocratic elution with acetonitrile-water (80:20, v/v) as the mobile phase at a flow rate of 0.4 mL/min. An electrospray ionization source was applied and operated in the positive ion mode; selected ion monitoring scan mode was used for quantification, and the target ions m/z 543.3 for cyasterone and m/z 581.3 for IS were chosen. Good linearity was observed in the concentration range of 0.40-400 ng/mL for cyasterone in rat plasma. Intra-day and inter-day precision were both <7.4%. This method was proved to be suitable for pharmacokinetic studies after oral (5.0 mg/kg) or intravenous (0.5 mg/kg) administration of cyasterone in rats. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Gas-diffusion microextraction coupled with spectrophotometry for the determination of formaldehyde in cork agglomerates.

PubMed

Brandão, Pedro F; Ramos, Rui M; Valente, Inês M; Almeida, Paulo J; Carro, Antonia M; Lorenzo, Rosa A; Rodrigues, José A

2017-04-01

In this work, a simple methodology was developed for the extraction and determination of free formaldehyde content in cork agglomerate samples. For the first time, gas-diffusion microextraction was used for the extraction of volatile formaldehyde directly from samples, with simultaneous derivatization with acetylacetone (Hantzsch reaction). The absorbance of the coloured solution was read in a spectrophotometer at 412 nm. Different extraction parameters were studied and optimized (extraction temperature, sample mass, volume of acceptor solution, extraction time and concentration of derivatization reagent) by means of an asymmetric screening. The developed methodology proved to be a reliable tool for the determination of formaldehyde in cork agglomerates with the following suitable method features: low LOD (0.14 mg kg -1 ) and LOQ (0.47 mg kg -1 ), r 2  = 0.9994, and intraday and interday precision of 3.5 and 4.9%, respectively. The developed methodology was applied to the determination of formaldehyde in different cork agglomerate samples, and contents between 1.9 and 9.4 mg kg -1 were found. Furthermore, formaldehyde was also determined by the standard method EN 717-3 for comparison purposes; no significant differences between the results of both methods were observed. Graphical abstract Representation of the GDME system and its main components.

Nanoparticle Tracking Analysis for the Enumeration and Characterization of Mineralo-Organic Nanoparticles in Feline Urine

PubMed Central

Mellema, M.; Stoller, M.; Queau, Y.; Ho, S. P.; Chi, T.; Larsen, J. A.; Passlack, N.; Fascetti, A. J.; Mohr, C.; Westropp, J. L.

2016-01-01

Urinary stone disease, particularly calcium oxalate, is common in both humans and cats. Calcifying nanoparticles (CNP) are spherical nanocrystallite material, and are composed of proteins (fetuin, albumin) and inorganic minerals. CNP are suggested to play a role in a wide array of pathologic mineralization syndromes including urolithiasis. We documented the development of a clinically relevant protocol to assess urinary CNP in 9 healthy cats consuming the same diet in a controlled environment using Nanoparticle Tracking Analysis (NTA®). NTA® is a novel method that allows for characterization of the CNP in an efficient, accurate method that can differentiate these particles from other urinary submicron particulates. The predominant nanoscale particles in feline urine are characteristic of CNP in terms of their size, their ability to spontaneously form under suitable conditions, and the presence of an outer layer that is rich in calcium and capable of binding to hydroxyapatite binders such as alendronate and osteopontin. The expansion of this particle population can be suppressed by the addition of citrate to urine samples. Further, compounds targeting exosomal surfaces do not label these particulates. As CNP have been associated with a number of significant urologic maladies, the method described herein may prove to be a useful adjunct in evaluating lithogenesis risk in mammals. PMID:28005930

SOR Lithography in West Germany

NASA Astrophysics Data System (ADS)

Heuberger, Anton

1989-08-01

The 64 Mbit DRAM will represent the first generation of integrated circuits which cannot be produced reasonably by means of optical lithography techniques. X-ray lithography using synchrotron radiation seems to be the most promising method in overcoming the problems in the sub-0.5 micron range. The first year of production of the 64 Mbit DRAM will be 1995 or 1996. This means that X-ray lithography has to show its applicability in an industrial environment by 1992 and has to prove that the specifications of a 64 Mbit DRAM technology can actually be achieved. Part of this task is a demonstration of production suitable equipment such as the X-ray stepper, including an appropriate X-ray source and measurement and inspection tools. The most important bottlenecks on the way toward reaching these goals are linked to the 1 x scale mask technology, especially the pattern definition accuracy and zero level of printing defects down to the order of magnitude of 50 nm. Specifically, fast defect detection methods on the basis of high resolution e-beam techniques and repair methods have to be developed. The other problems of X-ray lithography, such as high quality single layer X-ray resists, X-ray sources and stepper including alignment are either well on the way or are already solved.

Nanoparticle Tracking Analysis for the Enumeration and Characterization of Mineralo-Organic Nanoparticles in Feline Urine.

PubMed

Mellema, M; Stoller, M; Queau, Y; Ho, S P; Chi, T; Larsen, J A; Passlack, N; Fascetti, A J; Mohr, C; Westropp, J L

2016-01-01

Urinary stone disease, particularly calcium oxalate, is common in both humans and cats. Calcifying nanoparticles (CNP) are spherical nanocrystallite material, and are composed of proteins (fetuin, albumin) and inorganic minerals. CNP are suggested to play a role in a wide array of pathologic mineralization syndromes including urolithiasis. We documented the development of a clinically relevant protocol to assess urinary CNP in 9 healthy cats consuming the same diet in a controlled environment using Nanoparticle Tracking Analysis (NTA®). NTA® is a novel method that allows for characterization of the CNP in an efficient, accurate method that can differentiate these particles from other urinary submicron particulates. The predominant nanoscale particles in feline urine are characteristic of CNP in terms of their size, their ability to spontaneously form under suitable conditions, and the presence of an outer layer that is rich in calcium and capable of binding to hydroxyapatite binders such as alendronate and osteopontin. The expansion of this particle population can be suppressed by the addition of citrate to urine samples. Further, compounds targeting exosomal surfaces do not label these particulates. As CNP have been associated with a number of significant urologic maladies, the method described herein may prove to be a useful adjunct in evaluating lithogenesis risk in mammals.

Practical aspects of genetic identification of hallucinogenic and other poisonous mushrooms for clinical and forensic purposes.

PubMed

Kowalczyk, Marek; Sekuła, Andrzej; Mleczko, Piotr; Olszowy, Zofia; Kujawa, Anna; Zubek, Szymon; Kupiec, Tomasz

2015-02-01

To assess the usefulness of a DNA-based method for identifying mushroom species for application in forensic laboratory practice. Two hundred twenty-one samples of clinical forensic material (dried mushrooms, food remains, stomach contents, feces, etc) were analyzed. ITS2 region of nuclear ribosomal DNA (nrDNA) was sequenced and the sequen-ces were compared with reference sequences collected from the National Center for Biotechnology Information gene bank (GenBank). Sporological identification of mushrooms was also performed for 57 samples of clinical material. Of 221 samples, positive sequencing results were obtained for 152 (69%). The highest percentage of positive results was obtained for samples of dried mushrooms (96%) and food remains (91%). Comparison with GenBank sequences enabled identification of all samples at least at the genus level. Most samples (90%) were identified at the level of species or a group of closely related species. Sporological and molecular identification were consistent at the level of species or genus for 30% of analyzed samples. Molecular analysis identified a larger number of species than sporological method. It proved to be suitable for analysis of evidential material (dried hallucinogenic mushrooms) in forensic genetic laboratories as well as to complement classical methods in the analysis of clinical material.

Orthogonal Procrustes Analysis for Dictionary Learning in Sparse Linear Representation.

PubMed

Grossi, Giuliano; Lanzarotti, Raffaella; Lin, Jianyi

2017-01-01

In the sparse representation model, the design of overcomplete dictionaries plays a key role for the effectiveness and applicability in different domains. Recent research has produced several dictionary learning approaches, being proven that dictionaries learnt by data examples significantly outperform structured ones, e.g. wavelet transforms. In this context, learning consists in adapting the dictionary atoms to a set of training signals in order to promote a sparse representation that minimizes the reconstruction error. Finding the best fitting dictionary remains a very difficult task, leaving the question still open. A well-established heuristic method for tackling this problem is an iterative alternating scheme, adopted for instance in the well-known K-SVD algorithm. Essentially, it consists in repeating two stages; the former promotes sparse coding of the training set and the latter adapts the dictionary to reduce the error. In this paper we present R-SVD, a new method that, while maintaining the alternating scheme, adopts the Orthogonal Procrustes analysis to update the dictionary atoms suitably arranged into groups. Comparative experiments on synthetic data prove the effectiveness of R-SVD with respect to well known dictionary learning algorithms such as K-SVD, ILS-DLA and the online method OSDL. Moreover, experiments on natural data such as ECG compression, EEG sparse representation, and image modeling confirm R-SVD's robustness and wide applicability.

Landsat applied to landslide mapping

NASA Technical Reports Server (NTRS)

Sauchyn, D. J.; Trench, N. R.

1978-01-01

A variety of features characteristic of rotational landslides may be identified on Landsat imagery. These include tonal mottling, tonal banding, major and secondary scarps, and ponds. Pseudostereoscopic viewing of 9 by 9 in. transparencies was useful for the detailed identification of landslides, whereas 1:250,000 prints enlarged from 70 mm negatives were most suitable for regional analysis. Band 7 is the most useful band for landslide recognition, due to accentuation of ponds and shadows. Examination of both bands 7 and 5, including vegetation information, was found to be most suitable. Although, given optimum terrain conditions, some landslides in Colorado may be recognized, many smaller landslides are not identifiable. Consequently, Landsat is not recommended for detailed regional mapping, or for use in areas similar to Colorado, where alternative (aircraft) imagery is available. However, Landsat may prove useful for preliminary landslide mapping in relatively unknown areas.

Hierarchical Bayesian Modeling of Fluid-Induced Seismicity

NASA Astrophysics Data System (ADS)

Broccardo, M.; Mignan, A.; Wiemer, S.; Stojadinovic, B.; Giardini, D.

2017-11-01

In this study, we present a Bayesian hierarchical framework to model fluid-induced seismicity. The framework is based on a nonhomogeneous Poisson process with a fluid-induced seismicity rate proportional to the rate of injected fluid. The fluid-induced seismicity rate model depends upon a set of physically meaningful parameters and has been validated for six fluid-induced case studies. In line with the vision of hierarchical Bayesian modeling, the rate parameters are considered as random variables. We develop both the Bayesian inference and updating rules, which are used to develop a probabilistic forecasting model. We tested the Basel 2006 fluid-induced seismic case study to prove that the hierarchical Bayesian model offers a suitable framework to coherently encode both epistemic uncertainty and aleatory variability. Moreover, it provides a robust and consistent short-term seismic forecasting model suitable for online risk quantification and mitigation.

Fluidized bed combustion bottom ash: A better and alternative geo-material resource for construction.

PubMed

Mandal, A K; Paramkusam, Bala Ramudu; Sinha, O P

2018-04-01

Though the majority of research on fly ash has proved its worth as a construction material, the utility of bottom ash is yet questionable due to its generation during the pulverized combustion process. The bottom ash produced during the fluidized bed combustion (FBC) process is attracting more attention due to the novelty of coal combustion technology. But, to establish its suitability as construction material, it is necessary to characterize it thoroughly with respect to the geotechnical as well as mineralogical points of view. For fulfilling these objectives, the present study mainly aims at characterizing the FBC bottom ash and its comparison with pulverized coal combustion (PCC) bottom ash, collected from the same origin of coal. Suitability of FBC bottom ash as a dike filter material in contrast to PCC bottom ash in replacing traditional filter material such as sand was also studied. The suitability criteria for utilization of both bottom ash and river sand as filter material on pond ash as a base material were evaluated, and both river sand and FBC bottom ash were found to be satisfactory. The study shows that FBC bottom ash is a better geo-material than PCC bottom ash, and it could be highly recommended as an alternative suitable filter material for constructing ash dikes in place of conventional sand.

Energy Bounds for a Compressed Elastic Film on a Substrate

NASA Astrophysics Data System (ADS)

Bourne, David P.; Conti, Sergio; Müller, Stefan

2017-04-01

We study pattern formation in a compressed elastic film which delaminates from a substrate. Our key tool is the determination of rigorous upper and lower bounds on the minimum value of a suitable energy functional. The energy consists of two parts, describing the two main physical effects. The first part represents the elastic energy of the film, which is approximated using the von Kármán plate theory. The second part represents the fracture or delamination energy, which is approximated using the Griffith model of fracture. A simpler model containing the first term alone was previously studied with similar methods by several authors, assuming that the delaminated region is fixed. We include the fracture term, transforming the elastic minimisation into a free boundary problem, and opening the way for patterns which result from the interplay of elasticity and delamination. After rescaling, the energy depends on only two parameters: the rescaled film thickness, {σ }, and a measure of the bonding strength between the film and substrate, {γ }. We prove upper bounds on the minimum energy of the form {σ }^a {γ }^b and find that there are four different parameter regimes corresponding to different values of a and b and to different folding patterns of the film. In some cases, the upper bounds are attained by self-similar folding patterns as observed in experiments. Moreover, for two of the four parameter regimes we prove matching, optimal lower bounds.

A Novel Wearable Sensor-Based Human Activity Recognition Approach Using Artificial Hydrocarbon Networks.

PubMed

Ponce, Hiram; Martínez-Villaseñor, María de Lourdes; Miralles-Pechuán, Luis

2016-07-05

Human activity recognition has gained more interest in several research communities given that understanding user activities and behavior helps to deliver proactive and personalized services. There are many examples of health systems improved by human activity recognition. Nevertheless, the human activity recognition classification process is not an easy task. Different types of noise in wearable sensors data frequently hamper the human activity recognition classification process. In order to develop a successful activity recognition system, it is necessary to use stable and robust machine learning techniques capable of dealing with noisy data. In this paper, we presented the artificial hydrocarbon networks (AHN) technique to the human activity recognition community. Our artificial hydrocarbon networks novel approach is suitable for physical activity recognition, noise tolerance of corrupted data sensors and robust in terms of different issues on data sensors. We proved that the AHN classifier is very competitive for physical activity recognition and is very robust in comparison with other well-known machine learning methods.

Calibration of CR-39-based thoron progeny device.

PubMed

Fábián, F; Csordás, A; Shahrokhi, A; Somlai, J; Kovács, T

2014-07-01

Radon isotopes and their progenies have proven significant role in respiratory tumour formation. In most cases, the radiological effect of one of the radon isotopes (thoron) and its progenies has been neglected together with its measurement technique; however, latest surveys proved that thoron's existence is expectable in flats and in workplace in Europe. Detectors based on different track detector measurement technologies have recently spread for measuring thoron progenies; however, the calibration is not yet completely elaborated. This study deals with the calibration of the track detector measurement method suitable for measuring thoron progenies using different devices with measurement techniques capable of measuring several progenies (Pylon AB5 and WLx, Sarad EQF 3220). The calibration factor values related to the thoron progeny monitors, the measurement uncertainty, reproducibility and other parameters were found using the calibration chamber. In the future, the effects of the different parameters (aerosol distribution, etc.) will be determined. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Indirect adaptive fuzzy wavelet neural network with self- recurrent consequent part for AC servo system.

PubMed

Hou, Runmin; Wang, Li; Gao, Qiang; Hou, Yuanglong; Wang, Chao

2017-09-01

This paper proposes a novel indirect adaptive fuzzy wavelet neural network (IAFWNN) to control the nonlinearity, wide variations in loads, time-variation and uncertain disturbance of the ac servo system. In the proposed approach, the self-recurrent wavelet neural network (SRWNN) is employed to construct an adaptive self-recurrent consequent part for each fuzzy rule of TSK fuzzy model. For the IAFWNN controller, the online learning algorithm is based on back propagation (BP) algorithm. Moreover, an improved particle swarm optimization (IPSO) is used to adapt the learning rate. The aid of an adaptive SRWNN identifier offers the real-time gradient information to the adaptive fuzzy wavelet neural controller to overcome the impact of parameter variations, load disturbances and other uncertainties effectively, and has a good dynamic. The asymptotical stability of the system is guaranteed by using the Lyapunov method. The result of the simulation and the prototype test prove that the proposed are effective and suitable. Copyright © 2017. Published by Elsevier Ltd.

Practical Application Limits of Fuel Cells and Batteries for Zero Emission Vessels

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

Minnehan, John J.; Pratt, Joseph William

Batteries and hydrogen fuel cells provide zero emission power at the point of use. They are studied as an alternative powerplant for maritime vessels by considering 14 case studies of various ship sizes and routes varying from small passenger vessels to the largest cargo ships. The method used was to compare the mass and volume of the required zero emission solution to the available mass and volume on an existing vessel considering its current engine and fuel storage systems. The results show that it is practically feasible to consider these zero emission technologies for most vessels in the world's fleet.more » Hydrogen fuel cells proved to be the most capable while battery systems showed an advantage for high power, short duration missions. The results provide a guide to ship designers to determine the most suitable types of zero emission powerplants to fit a ship based on its size and energy requirements.« less

Convergence of damped inertial dynamics governed by regularized maximally monotone operators

NASA Astrophysics Data System (ADS)

Attouch, Hedy; Cabot, Alexandre

2018-06-01

In a Hilbert space setting, we study the asymptotic behavior, as time t goes to infinity, of the trajectories of a second-order differential equation governed by the Yosida regularization of a maximally monotone operator with time-varying positive index λ (t). The dissipative and convergence properties are attached to the presence of a viscous damping term with positive coefficient γ (t). A suitable tuning of the parameters γ (t) and λ (t) makes it possible to prove the weak convergence of the trajectories towards zeros of the operator. When the operator is the subdifferential of a closed convex proper function, we estimate the rate of convergence of the values. These results are in line with the recent articles by Attouch-Cabot [3], and Attouch-Peypouquet [8]. In this last paper, the authors considered the case γ (t) = α/t, which is naturally linked to Nesterov's accelerated method. We unify, and often improve the results already present in the literature.

Fluorine-18 radiolabeling of low-density lipoproteins: a potential approach for characterization and differentiation of metabolism of native and oxidized low-density lipoproteins in vivo.

PubMed

Pietzsch, Jens; Bergmann, Ralf; Rode, Katrin; Hultsch, Christina; Pawelke, Beate; Wuest, Frank; van den Hoff, Joerg

2004-11-01

Oxidative modification of low-density lipoprotein (LDL) is regarded as a crucial event in atherogenesis. Assessing the metabolic fate of oxidized LDL (oxLDL) in vivo with radiotracer techniques is hindered by the lack of suitable sensitive and specific radiolabeling methods. We evaluated an improved methodology based on the radiolabeling of native LDL (nLDL) and oxLDL with the positron emitter fluorine-18 ((18)F) by conjugation with N-succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB). We investigated whether radiolabeling of LDL induces adverse structural modifications. Results suggest that radiolabeling of both nLDL and oxLDL using [(18)F]SFB causes neither additional oxidative structural modifications of LDL lipids and proteins nor alteration of their biological activity and functionality, respectively. Thus, radiolabeling of LDL using [(18)F]SFB could prove to be a promising approach for studying the kinetics of oxLDL in vivo.

A Grey Fuzzy Logic Approach for Cotton Fibre Selection

NASA Astrophysics Data System (ADS)

Chakraborty, Shankar; Das, Partha Protim; Kumar, Vidyapati

2017-06-01

It is a well known fact that the quality of ring spun yarn predominantly depends on various physical properties of cotton fibre. Any variation in these fibre properties may affect the strength and unevenness of the final yarn. Thus, so as to achieve the desired yarn quality and characteristics, it becomes imperative for the spinning industry personnel to identify the most suitable cotton fibre from a set of feasible alternatives in presence of several conflicting properties/attributes. This cotton fibre selection process can be modelled as a Multi-Criteria Decision Making (MCDM) problem. In this paper, a grey fuzzy logic-based approach is proposed for selection of the most apposite cotton fibre from 17 alternatives evaluated based on six important fibre properties. It is observed that the preference order of the top-ranked cotton fibres derived using the grey fuzzy logic approach closely matches with that attained by the past researchers which proves the application potentiality of this method in solving varying MCDM problems in textile industries.

Synthesis and Evaluation of GM2-Monophosphoryl Lipid A Conjugate as a Fully Synthetic Self-Adjuvant Cancer Vaccine.

PubMed

Zhou, Zhifang; Mandal, Satadru S; Liao, Guochao; Guo, Jiatong; Guo, Zhongwu

2017-09-12

An efficient method was developed for the synthesis of a GM2 derivative suitable for the conjugation with various biomolecules. This GM2 derivative was covalently linked to keyhole limpet hemocyanin (KLH) and monophosphoryl lipid A (MPLA) to form novel therapeutic cancer vaccines. Immunological evaluations of the resultant conjugates in mice revealed that they elicited robust GM2-specific overall and IgG antibody responses. Moreover, the GM2-MPLA conjugate was disclosed to elicit strong immune responses without the use of an adjuvant, proving its self-adjuvant property. The antisera of both conjugates showed strong binding and mediated similarly effective complement-dependent cytotoxicity to GM2-expressing cancer cell line MCF-7. Based on these results, it was concluded that both GM2-MPLA and GM2-KLH are promising candidates as therapeutic cancer vaccines, whereas fully synthetic GM2-MPLA, which has homogeneous and well-defined structure and self-adjuvant property, deserves more attention and studies.

Prostate Cancer Chemoprevention Targeting Men with High-Grade Prostatic Intraepithelial Neoplasia (HGPIN) and Atypical Small Acinar Proliferation (ASAP): Model for Trial Design and Outcome Measures.

PubMed

Kumar, Nagi; Crocker, Theresa; Smith, Tiffany; Connors, Shahnjayla; Pow-Sang, Julio; Spiess, Philippe E; Egan, Kathleen; Quinn, Gwen; Schell, Michael; Sebti, Said; Kazi, Aslam; Chuang, Tian; Salup, Raoul; Helal, Mohamed; Zagaja, Gregory; Trabulsi, Edouard; McLarty, Jerry; Fazili, Tajammul; Williams, Christopher R; Schreiber, Fred; Anderson, Kyle

2012-01-21

In spite of the large number of nutrient-derived agents demonstrating promise as potential chemopreventive agents, most have failed to prove effectiveness in clinical trials. Critical requirements for moving nutrient-derived agents to recommendation for clinical use include adopting a systematic, molecular-mechanism based approach and utilizing the same ethical and rigorous methods such as are used to evaluate other pharmacological agents. Preliminary data on a mechanistic rationale for chemoprevention activity as observed from epidemiological, in vitro and preclinical studies, phase I data of safety in suitable cohorts, duration of intervention based on time to progression of preneoplastic disease to cancer and the use of a valid panel of biomarkers representing the hypothesized carcinogenesis pathway for measuring efficacy must inform the design of phase II clinical trials. The goal of this paper is to provide a model for evaluating a well characterized agent- Polyphenon E- in a phase II clinical trial of prostate cancer chemoprevention.

Prostate Cancer Chemoprevention Targeting Men with High-Grade Prostatic Intraepithelial Neoplasia (HGPIN) and Atypical Small Acinar Proliferation (ASAP): Model for Trial Design and Outcome Measures

PubMed Central

Kumar, Nagi; Crocker, Theresa; Smith, Tiffany; Connors, Shahnjayla; Pow-Sang, Julio; Spiess, Philippe E.; Egan, Kathleen; Quinn, Gwen; Schell, Michael; Sebti, Said; Kazi, Aslam; Chuang, Tian; Salup, Raoul; Helal, Mohamed; Zagaja, Gregory; Trabulsi, Edouard; McLarty, Jerry; Fazili, Tajammul; Williams, Christopher R.; Schreiber, Fred; Anderson, Kyle

2014-01-01

In spite of the large number of nutrient-derived agents demonstrating promise as potential chemopreventive agents, most have failed to prove effectiveness in clinical trials. Critical requirements for moving nutrient-derived agents to recommendation for clinical use include adopting a systematic, molecular-mechanism based approach and utilizing the same ethical and rigorous methods such as are used to evaluate other pharmacological agents. Preliminary data on a mechanistic rationale for chemoprevention activity as observed from epidemiological, in vitro and preclinical studies, phase I data of safety in suitable cohorts, duration of intervention based on time to progression of preneoplastic disease to cancer and the use of a valid panel of biomarkers representing the hypothesized carcinogenesis pathway for measuring efficacy must inform the design of phase II clinical trials. The goal of this paper is to provide a model for evaluating a well characterized agent- Polyphenon E- in a phase II clinical trial of prostate cancer chemoprevention. PMID:24533253

Problematic topic transitions in dysarthric conversation.

PubMed

Bloch, Steven; Saldert, Charlotta; Ferm, Ulrika

2015-01-01

This study examined the nature of topic transition problems associated with acquired progressive dysarthric speech in the everyday conversation of people with motor neurone disease. Using conversation analytic methods, a video collection of five naturally occurring problematic topic transitions was identified, transcribed and analysed. These were extracted from a main collection of over 200 other-initiated repair sequences and a sub-set of 15 problematic topic transition sequences. The sequences were analysed with reference to how the participants both identified and resolved the problems. Analysis revealed that topic transition by people with dysarthria can prove problematic. Conversation partners may find transitions problematic not only because of speech intelligibility but also because of a sequential disjuncture between the dysarthric speech turn and whatever topic has come prior. In addition the treatment of problematic topic transition as a complaint reveals the potential vulnerability of people with dysarthria to judgements of competence. These findings have implications for how dysarthria is conceptualized and how specific actions in conversation, such as topic transition, might be suitable targets for clinical intervention.

Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

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

Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my

2015-07-22

Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) andmore » proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.« less

Towards a petawatt-class few-cycle infrared laser system via dual-chirped optical parametric amplification.

PubMed

Fu, Yuxi; Midorikawa, Katsumi; Takahashi, Eiji J

2018-05-16

Expansion of the wavelength range for an ultrafast laser is an important ingredient for extending its range of applications. Conventionally, optical parametric amplification (OPA) has been employed to expand the laser wavelength to the infrared (IR) region. However, the achievable pulse energy and peak power have been limited to the mJ and the GW level, respectively. A major difficulty in the further energy scaling of OPA results from a lack of suitable large nonlinear crystals. Here, we circumvent this difficulty by employing a dual-chirped optical parametric amplification (DC-OPA) scheme. We successfully generate a multi-TW IR femtosecond laser pulse with an energy of 100 mJ order, which is higher than that reported in previous works. We also obtain excellent energy scaling ability, ultrashort pulses, flexiable wavelength tunability, and high-energy stability, which prove that DC-OPA is a superior method for the energy scaling of IR pulses to the 10 J/PW level.

A Novel Strain-Based Method to Estimate Tire Conditions Using Fuzzy Logic for Intelligent Tires.

PubMed

Garcia-Pozuelo, Daniel; Olatunbosun, Oluremi; Yunta, Jorge; Yang, Xiaoguang; Diaz, Vicente

2017-02-10

The so-called intelligent tires are one of the most promising research fields for automotive engineers. These tires are equipped with sensors which provide information about vehicle dynamics. Up to now, the commercial intelligent tires only provide information about inflation pressure and their contribution to stability control systems is currently very limited. Nowadays one of the major problems for intelligent tire development is how to embed feasible and low cost sensors to obtain reliable information such as inflation pressure, vertical load or rolling speed. These parameters provide key information for vehicle dynamics characterization. In this paper, we propose a novel algorithm based on fuzzy logic to estimate the mentioned parameters by means of a single strain-based system. Experimental tests have been carried out in order to prove the suitability and durability of the proposed on-board strain sensor system, as well as its low cost advantages, and the accuracy of the obtained estimations by means of fuzzy logic.

Real time study of amalgam formation and mercury adsorption on thin gold film by total internal reflection ellipsometry

NASA Astrophysics Data System (ADS)

Paulauskas, A.; Selskis, A.; Bukauskas, V.; Vaicikauskas, V.; Ramanavicius, A.; Balevicius, Z.

2018-01-01

Total internal reflection ellipsometry (TIRE) was utilized in its dynamic data acquisition mode to reveal the percentage of mercury present in an amalgam surface layer. In determining the optical constants of the amalgam film, the non-homogeneities of the formed surface layer were taken into account. The composition of the amalgam layer by percentage was determined using the EMA Bruggemann model for the analysis of the TIRE data. Regression results showed that amalgam layer consisted of mercury 16.00 ± 0.43% and gold 84.00 ± 0.43%. This real time TIRE analysis has shown that for these studies method can detect 0.6 ± 0.4% of mercury on a gold surface, proving that this is a suitable optical technique for obtaining real time readouts. The structural analysis of SEM and AFM have shown that the amalgam layer had a dendritic structure, which formation was determined by the weak adhesion of the gold atoms onto its surface.

A compact model and direct parameters extraction techniques For amorphous gallium-indium-zinc-oxide thin film transistors

NASA Astrophysics Data System (ADS)

Moldovan, Oana; Castro-Carranza, Alejandra; Cerdeira, Antonio; Estrada, Magali; Barquinha, Pedro; Martins, Rodrigo; Fortunato, Elvira; Miljakovic, Slobodan; Iñiguez, Benjamin

2016-12-01

An advanced compact and analytical drain current model for the amorphous gallium indium zinc oxide (GIZO) thin film transistors (TFTs) is proposed. Its output saturation behavior is improved by introducing a new asymptotic function. All model parameters were extracted using an adapted version of the Universal Method and Extraction Procedure (UMEM) applied for the first time for GIZO devices in a simple and direct form. We demonstrate the correct behavior of the model for negative VDS, a necessity for a complete compact model. In this way we prove the symmetry of source and drain electrodes and extend the range of applications to both signs of VDS. The model, in Verilog-A code, is implemented in Electronic Design Automation (EDA) tools, such as Smart Spice, and compared with measurements of TFTs. It describes accurately the experimental characteristics in the whole range of GIZO TFTs operation, making the model suitable for the design of circuits using these types of devices.

SABRE-Relay: A Versatile Route to Hyperpolarization.

PubMed

Roy, Soumya S; Appleby, Kate M; Fear, Elizabeth J; Duckett, Simon B

2018-03-01

Signal Amplification by Reversible Exchange (SABRE) is used to switch on the latent singlet spin order of para-hydrogen (p-H 2 ) so that it can hyperpolarize a substrate (sub = nicotinamide, nicotinate, niacin, pyrimidine, and pyrazine). The substrate then reacts reversibly with [Pt(OTf) 2 (bis-diphenylphosphinopropane)] by displacing OTf - to form [Pt(OTf)(sub)(bis-diphenylphosphinopropane)]OTf. The 31 P NMR signals of these metal complexes prove to be enhanced when the substrate possesses an accessible singlet state or long-lived Zeeman polarization. In the case of pyrazine, the corresponding 31 P signal was 105 ± 8 times larger than expected, which equated to an 8 h reduction in total scan time for an equivalent signal-to-noise ratio under normal acquisition conditions. Hence, p-H 2 derived spin order is successfully relayed into a second metal complex via a suitable polarization carrier (sub). When fully developed, we expect this route involving a second catalyst to successfully hyperpolarize many classes of substrates that are not amenable to the original SABRE method.

SABRE-Relay: A Versatile Route to Hyperpolarization

PubMed Central

2018-01-01

Signal Amplification by Reversible Exchange (SABRE) is used to switch on the latent singlet spin order of para-hydrogen (p-H2) so that it can hyperpolarize a substrate (sub = nicotinamide, nicotinate, niacin, pyrimidine, and pyrazine). The substrate then reacts reversibly with [Pt(OTf)2(bis-diphenylphosphinopropane)] by displacing OTf– to form [Pt(OTf)(sub)(bis-diphenylphosphinopropane)]OTf. The 31P NMR signals of these metal complexes prove to be enhanced when the substrate possesses an accessible singlet state or long-lived Zeeman polarization. In the case of pyrazine, the corresponding 31P signal was 105 ± 8 times larger than expected, which equated to an 8 h reduction in total scan time for an equivalent signal-to-noise ratio under normal acquisition conditions. Hence, p-H2 derived spin order is successfully relayed into a second metal complex via a suitable polarization carrier (sub). When fully developed, we expect this route involving a second catalyst to successfully hyperpolarize many classes of substrates that are not amenable to the original SABRE method. PMID:29432020

Heterodyne-detected dispersed vibrational echo spectroscopy.

PubMed

Jones, Kevin C; Ganim, Ziad; Tokmakoff, Andrei

2009-12-24

We develop heterodyned dispersed vibrational echo spectroscopy (HDVE) and demonstrate the new capabilities in biophysical applications. HDVE is a robust ultrafast technique that provides a characterization of the real and imaginary components of third-order nonlinear signals with high sensitivity and single-laser-shot capability and can be used to extract dispersed pump-probe and dispersed vibrational echo spectra. Four methods for acquiring HDVE phase and amplitude spectra were compared: Fourier transform spectral interferometry, a new phase modulation spectral interferometry technique, and combination schemes. These extraction techniques were demonstrated in the context of protein amide I spectroscopy. Experimental HDVE and heterodyned free induction decay amide I spectra were explicitly compared to conventional dispersed pump-probe, dispersed vibrational echo, and absorption spectra. The new capabilities of HDVE were demonstrated by acquiring single-shot spectra and melting curves of ubiquitin and concentration-dependent spectra of insulin suitable for extracting the binding constant for dimerization. The introduced techniques will prove particularly useful in transient experiments, studying irreversible reactions, and micromolar concentration studies of small proteins.

OSL studies of alkali fluoroperovskite single crystals for radiation dosimetry

NASA Astrophysics Data System (ADS)

Daniel, D. Joseph; Raja, A.; Madhusoodanan, U.; Annalakshmi, O.; Ramasamy, P.

2016-08-01

This paper presents a preliminary investigation of the optically stimulated luminescence (OSL) of alkali fluoroperovskite single crystals for radiation dosimetry. The perovskite-like KMgF3, NaMgF3 and LiBaF3 polycrystalline compounds doped with rare earths (Eu2+ and Ce3+) were synthesized by standard solid state reaction technique. Phase purity of the synthesized compounds was analyzed by powder X-ray diffraction technique. Single crystals of these compounds have been grown from melt by using vertical Bridgman-Stockbarger method. The Linearly Modulated OSL and Continuous Wave OSL measurements were performed in these alkali fluorides using blue light stimulation. Thermal bleaching experiments have shown that OSL signals originate from traps which are unstable near 200 °C, thus proving the suitability of the signals for dosimetric purposes. Optical bleaching measurements were also performed for these fluoride samples. OSL dose response was studied as a function of dose which was found to increase with beta dose.

A Novel Flexible Inertia Weight Particle Swarm Optimization Algorithm.

PubMed

Amoshahy, Mohammad Javad; Shamsi, Mousa; Sedaaghi, Mohammad Hossein

2016-01-01

Particle swarm optimization (PSO) is an evolutionary computing method based on intelligent collective behavior of some animals. It is easy to implement and there are few parameters to adjust. The performance of PSO algorithm depends greatly on the appropriate parameter selection strategies for fine tuning its parameters. Inertia weight (IW) is one of PSO's parameters used to bring about a balance between the exploration and exploitation characteristics of PSO. This paper proposes a new nonlinear strategy for selecting inertia weight which is named Flexible Exponential Inertia Weight (FEIW) strategy because according to each problem we can construct an increasing or decreasing inertia weight strategy with suitable parameters selection. The efficacy and efficiency of PSO algorithm with FEIW strategy (FEPSO) is validated on a suite of benchmark problems with different dimensions. Also FEIW is compared with best time-varying, adaptive, constant and random inertia weights. Experimental results and statistical analysis prove that FEIW improves the search performance in terms of solution quality as well as convergence rate.

A Novel Flexible Inertia Weight Particle Swarm Optimization Algorithm

PubMed Central

Shamsi, Mousa; Sedaaghi, Mohammad Hossein

2016-01-01

Particle swarm optimization (PSO) is an evolutionary computing method based on intelligent collective behavior of some animals. It is easy to implement and there are few parameters to adjust. The performance of PSO algorithm depends greatly on the appropriate parameter selection strategies for fine tuning its parameters. Inertia weight (IW) is one of PSO’s parameters used to bring about a balance between the exploration and exploitation characteristics of PSO. This paper proposes a new nonlinear strategy for selecting inertia weight which is named Flexible Exponential Inertia Weight (FEIW) strategy because according to each problem we can construct an increasing or decreasing inertia weight strategy with suitable parameters selection. The efficacy and efficiency of PSO algorithm with FEIW strategy (FEPSO) is validated on a suite of benchmark problems with different dimensions. Also FEIW is compared with best time-varying, adaptive, constant and random inertia weights. Experimental results and statistical analysis prove that FEIW improves the search performance in terms of solution quality as well as convergence rate. PMID:27560945

Lunar oxygen and metal for use in near-Earth space: Magma electrolysis

NASA Technical Reports Server (NTRS)

Colson, Russell O.; Haskin, Larry A.

1990-01-01

Because it is energetically easier to get material from the Moon to Earth orbit than from the Earth itself, the Moon is a potentially valuable source of materials for use in space. The unique conditions on the Moon, such as vacuum, absence of many reagents common on the Earth, and the presence of very nontraditional ores suggest that a unique and nontraditional process for extracting materials from the ores may prove the most practical. With this in mind, an investigation of unfluxed silicate electrolysis as a method for extracting oxygen, iron, and silicon from lunar regolith was initiated and is discussed. The advantages of the process include simplicity of concept, absence of need to supply reagents from Earth, and low power and mass requirements for the processing plant. Disadvantages include the need for uninterrupted high temperature and the highly corrosive nature of the high-temperature silicate melts which has made identifying suitable electrode and container materials difficult.

Atmospheric pressure MALDI for the noninvasive characterization of carbonaceous ink from Renaissance documents.

PubMed

Grasso, Giuseppe; Calcagno, Marzia; Rapisarda, Alessandro; D'Agata, Roberta; Spoto, Giuseppe

2017-06-01

The analytical methods that are usually applied to determine the compositions of inks from ancient manuscripts usually focus on inorganic components, as in the case of iron gall ink. In this work, we describe the use of atmospheric pressure/matrix-assisted laser desorption ionization-mass spectrometry (AP/MALDI-MS) as a spatially resolved analytical technique for the study of the organic carbonaceous components of inks used in handwritten parts of ancient books for the first time. Large polycyclic aromatic hydrocarbons (L-PAH) were identified in situ in the ink of XVII century handwritten documents. We prove that it is possible to apply MALDI-MS as a suitable microdestructive diagnostic tool for analyzing samples in air at atmospheric pressure, thus simplifying investigations of the organic components of artistic and archaeological objects. The interpretation of the experimental MS results was supported by independent Raman spectroscopic investigations. Graphical abstract Atmospheric pressure/MALDI mass spectrometry detects in situ polycyclic aromatic hydrocarbons in the carbonaceous ink of XVII century manuscripts.

A Novel Strain-Based Method to Estimate Tire Conditions Using Fuzzy Logic for Intelligent Tires

PubMed Central

Garcia-Pozuelo, Daniel; Olatunbosun, Oluremi; Yunta, Jorge; Yang, Xiaoguang; Diaz, Vicente

2017-01-01

The so-called intelligent tires are one of the most promising research fields for automotive engineers. These tires are equipped with sensors which provide information about vehicle dynamics. Up to now, the commercial intelligent tires only provide information about inflation pressure and their contribution to stability control systems is currently very limited. Nowadays one of the major problems for intelligent tire development is how to embed feasible and low cost sensors to obtain reliable information such as inflation pressure, vertical load or rolling speed. These parameters provide key information for vehicle dynamics characterization. In this paper, we propose a novel algorithm based on fuzzy logic to estimate the mentioned parameters by means of a single strain-based system. Experimental tests have been carried out in order to prove the suitability and durability of the proposed on-board strain sensor system, as well as its low cost advantages, and the accuracy of the obtained estimations by means of fuzzy logic. PMID:28208631

A design of strategic alliance based on value chain of surveying and mapping enterprises in China

NASA Astrophysics Data System (ADS)

Duan, Hong; Huang, Xianfeng

2007-06-01

In this paper, we use value chain and strategic alliance theories to analyzing the surveying and mapping Industry and enterprises. The value chain of surveying and mapping enterprises is highly-contacted but split by administrative interference, the enterprises are common small scale. According to the above things, we consider that establishing a nonequity- Holding strategic alliance based on value chain is an available way, it can not only let the enterprises share the superior resources in different sectors of the whole value chain each other but avoid offending the interests of related administrative departments, by this way, the surveying and mapping enterprises gain development respectively and totally. Then, we give the method to building up the strategic alliance model through parting the value chain and the using advantage of companies in different value chain sectors. Finally, we analyze the internal rule of strategic alliance and prove it is a suitable way to realize the development of surveying and mapping enterprises through game theory.

Artificial Neural Network Based Mission Planning Mechanism for Spacecraft

NASA Astrophysics Data System (ADS)

Li, Zhaoyu; Xu, Rui; Cui, Pingyuan; Zhu, Shengying

2018-04-01

The ability to plan and react fast in dynamic space environments is central to intelligent behavior of spacecraft. For space and robotic applications, many planners have been used. But it is difficult to encode the domain knowledge and directly use existing techniques such as heuristic to improve the performance of the application systems. Therefore, regarding planning as an advanced control problem, this paper first proposes an autonomous mission planning and action selection mechanism through a multiple layer perceptron neural network approach to select actions in planning process and improve efficiency. To prove the availability and effectiveness, we use autonomous mission planning problems of the spacecraft, which is a sophisticated system with complex subsystems and constraints as an example. Simulation results have shown that artificial neural networks (ANNs) are usable for planning problems. Compared with the existing planning method in EUROPA, the mechanism using ANNs is more efficient and can guarantee stable performance. Therefore, the mechanism proposed in this paper is more suitable for planning problems of spacecraft that require real time and stability.

Design and analysis of the trapeziform and flat acoustic cloaks with controllable invisibility performance in a quasi-space

NASA Astrophysics Data System (ADS)

Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Xiong, Jie; Jiang, Ping

2015-07-01

We present the design, implementation and detailed performance analysis for a class of trapeziform and flat acoustic cloaks. An effective large invisible area is obtained compared with the traditional carpet cloak. The cloaks are realized with homogeneous metamaterials which are made of periodic arrangements of subwavelength unit cells composed of steel embedded in air. The microstructures and its effective parameters of the cloaks are determined quickly and precisely in a broadband frequency range by using the effective medium theory and the proposed parameters optimization method. The invisibility capability of the cloaks can be controlled by the variation of the key design parameters and scale factor which are proved to have more influence on the performance in the near field than that in the far field. Different designs are suitable for different application situations. Good cloaking performance demonstrates that such a device can be physically realized with natural materials which will greatly promote the real applications of invisibility cloak.

Landfill leachate sludge use as soil additive prior and after electrocoagulation treatment: A cytological assessment using CHO-k1 cells.

PubMed

Morozesk, M; Bonomo, M M; Rocha, L D; Duarte, I D; Zanezi, E R L; Jesus, H C; Fernandes, M N; Matsumoto, S T

2016-09-01

Electrocoagulation has recently attracted attention as a potential technique for treating toxic effluents due to its versatility and environmental compatibility, generating a residue chemically suitable to be used as a soil additive. In the present study, landfill leachate sludge hazardous effects were investigated prior and after electrocoagulation process using in vitro assays with the mammalian cells CHO-k1. An integrated strategy for risk assessment was used to correctly estimate the possible adverse landfill leachate sludge effects on human health and ecosystem. Electrocoagulation process proved to be an effective treatment due to possibility to improve effluent adverse characteristics and produce sludge with potential to be used as soil additive. Despite low cytoxicity, the residue presented genotoxic and mutagenic effects, indicating a capacity to induce genetic damages, probably due to induction of polyploidization process in cells. The observed effects demand an improvement of waste management methods for reduce negative risks of landfill leachate sludge application. Copyright © 2016 Elsevier Ltd. All rights reserved.

A priori Estimates for 3D Incompressible Current-Vortex Sheets

NASA Astrophysics Data System (ADS)

Coulombel, J.-F.; Morando, A.; Secchi, P.; Trebeschi, P.

2012-04-01

We consider the free boundary problem for current-vortex sheets in ideal incompressible magneto-hydrodynamics. It is known that current-vortex sheets may be at most weakly (neutrally) stable due to the existence of surface waves solutions to the linearized equations. The existence of such waves may yield a loss of derivatives in the energy estimate of the solution with respect to the source terms. However, under a suitable stability condition satisfied at each point of the initial discontinuity and a flatness condition on the initial front, we prove an a priori estimate in Sobolev spaces for smooth solutions with no loss of derivatives. The result of this paper gives some hope for proving the local existence of smooth current-vortex sheets without resorting to a Nash-Moser iteration. Such result would be a rigorous confirmation of the stabilizing effect of the magnetic field on Kelvin-Helmholtz instabilities, which is well known in astrophysics.

Traffic-Aware Channel Allocation and Routing in Multichannel, Multi-Radio Wireless Networks

DTIC Science & Technology

2012-01-01

come up with interesting ideas that eventually led me to my Ph.D. research topic that is presented in the Chapter 5 of this disserta- tion. Next, I...exam process. Their comments and suggestions helped me im- prove my research topic and project it in a perspective suitable for a wider audience. I...backo , and xed rate header transmissions. These overheads become prominent in short packets that are transmitted at high data rates. We address this

Antiferromagnetic Potts Model on the Erdős-Rényi Random Graph

NASA Astrophysics Data System (ADS)

Contucci, Pierluigi; Dommers, Sander; Giardinà, Cristian; Starr, Shannon

2013-10-01

We study the antiferromagnetic Potts model on the Poissonian Erdős-Rényi random graph. By identifying a suitable interpolation structure and an extended variational principle, together with a positive temperature second-moment analysis we prove the existence of a phase transition at a positive critical temperature. Upper and lower bounds on the temperature critical value are obtained from the stability analysis of the replica symmetric solution (recovered in the framework of Derrida-Ruelle probability cascades) and from an entropy positivity argument.

Stress regularity in quasi-static perfect plasticity with a pressure dependent yield criterion

NASA Astrophysics Data System (ADS)

Babadjian, Jean-François; Mora, Maria Giovanna

2018-04-01

This work is devoted to establishing a regularity result for the stress tensor in quasi-static planar isotropic linearly elastic - perfectly plastic materials obeying a Drucker-Prager or Mohr-Coulomb yield criterion. Under suitable assumptions on the data, it is proved that the stress tensor has a spatial gradient that is locally squared integrable. As a corollary, the usual measure theoretical flow rule is expressed in a strong form using the quasi-continuous representative of the stress.

Transverse instability of periodic and generalized solitary waves for a fifth-order KP model

NASA Astrophysics Data System (ADS)

Haragus, Mariana; Wahlén, Erik

2017-02-01

We consider a fifth-order Kadomtsev-Petviashvili equation which arises as a two-dimensional model in the classical water-wave problem. This equation possesses a family of generalized line solitary waves which decay exponentially to periodic waves at infinity. We prove that these solitary waves are transversely spectrally unstable and that this instability is induced by the transverse instability of the periodic tails. We rely upon a detailed spectral analysis of some suitably chosen linear operators.

University role in astronaut life support systems: Space power supply systems

NASA Technical Reports Server (NTRS)

Chin, L. Y.

1972-01-01

A brief description is given of the schemes suggested for providing electrical power aboard spacecraft. An attempt was made to list the major advantages and disadvantages of each scheme and to identify the particular areas in which it appears likely further research work may prove fruitful. Special attention was given to those research areas that appear suitable for colleges and university work. Chemical, solar, and nuclear power sources are considered together with the appropriate thermoelectric and turboelectric conversion systems.

Clinical use of isotope cardiac pacemakers (in German)

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

Wagner, J.; Kreutzberg, B.

1973-01-01

Plutoninm-235 having a half-life of 86.4 yrs has proved suitable as a long-life energy source for a cardiac pacemaker. The radiation dose of this pacemaker is below the I. C. R. P.-recommended values. As the isotope pacemaker costs three times as much as a conventional pacemaker, the merits of implanting an isotope pacemaker vs. the conventional kind are discussed. A survey is given of the cases in which an isotope pacemaker has been used. (GE)

[The Italian version of Nordic Musculoskeletal Standardized Questionnaire].

PubMed

Ghersi, R; Martinelli, S; Richeldi, A; Clerici, P; Grazioli, P; Gobba, F M

2007-01-01

We translated into Italian the Nordic musculoskelethal questionnaire, as completed by Canadian IRSST with Authors' agreement in 2001, according to OMS recommendations. This translation involved the following items: aches and troubles of neck, dorsal region, low back, shoulders, elbows, hands and wrists, hips and thighs, ankles and feet in the last 12 months. The questionnaire was then submitted to reliability and stability tests. The Italian version of the questionnaire, already used in different languages, proved to be suitable and reliable also for self administration.

Global existence and energy decay rates for a Kirchhoff-type wave equation with nonlinear dissipation.

PubMed

Kim, Daewook; Kim, Dojin; Hong, Keum-Shik; Jung, Il Hyo

2014-01-01

The first objective of this paper is to prove the existence and uniqueness of global solutions for a Kirchhoff-type wave equation with nonlinear dissipation of the form Ku'' + M(|A (1/2) u|(2))Au + g(u') = 0 under suitable assumptions on K, A, M(·), and g(·). Next, we derive decay estimates of the energy under some growth conditions on the nonlinear dissipation g. Lastly, numerical simulations in order to verify the analytical results are given.

A comparison theorem for the SOR iterative method

NASA Astrophysics Data System (ADS)

Sun, Li-Ying

2005-09-01

In 1997, Kohno et al. have reported numerically that the improving modified Gauss-Seidel method, which was referred to as the IMGS method, is superior to the SOR iterative method. In this paper, we prove that the spectral radius of the IMGS method is smaller than that of the SOR method and Gauss-Seidel method, if the relaxation parameter [omega][set membership, variant](0,1]. As a result, we prove theoretically that this method is succeeded in improving the convergence of some classical iterative methods. Some recent results are improved.

Using an innovative combination of quality-by-design and green analytical chemistry approaches for the development of a stability indicating UHPLC method in pharmaceutical products.

PubMed

Boussès, Christine; Ferey, Ludivine; Vedrines, Elodie; Gaudin, Karen

2015-11-10

An innovative combination of green chemistry and quality by design (QbD) approach is presented through the development of an UHPLC method for the analysis of the main degradation products of dextromethorphan hydrobromide. QbD strategy was integrated to the field of green analytical chemistry to improve method understanding while assuring quality and minimizing environmental impacts, and analyst exposure. This analytical method was thoroughly evaluated by applying risk assessment and multivariate analysis tools. After a scouting phase aimed at selecting a suitable stationary phase and an organic solvent in accordance with green chemistry principles, quality risk assessment tools were applied to determine the critical process parameters (CPPs). The effects of the CPPs on critical quality attributes (CQAs), i.e., resolutions, efficiencies, and solvent consumption were further evaluated by means of a screening design. A response surface methodology was then carried out to model CQAs as function of the selected CPPs and the optimal separation conditions were determined through a desirability analysis. Resulting contour plots enabled to establish the design space (DS) (method operable design region) where all CQAs fulfilled the requirements. An experimental validation of the DS proved that quality within the DS was guaranteed; therefore no more robustness study was required before the validation. Finally, this UHPLC method was validated using the concept of total error and was used to analyze a pharmaceutical drug product. Copyright © 2015 Elsevier B.V. All rights reserved.

Improvement in the physiological function and standing stability based on kinect multimedia for older people

PubMed Central

Chen, Chih-Chen

2016-01-01

[Purpose] The increase in the Taiwanese older population is associated with age-related inconveniences. Finding adequate and simple physical activities to help the older people maintaining their physiological function and preventing them from falls has become an urgent social issue. [Subjects and Methods] This study aimed to design a virtual exercise training game suitable for Taiwanese older people. This system will allow for the maintenance of the physiological function and standing stability through physical exercise, while using a virtual reality game. The participants can easily exercise in a carefree, interactive environment. This study will use Kinect for Windows for physical movement detection and Unity software for virtual world development. [Results] Group A and B subjects were involved in the exercise training method of Kinect interactive multimedia for 12 weeks. The results showed that the functional reach test and the unipedal stance test improved significantly. [Conclusion] The physiological function and standing stability of the group A subjects were examined at six weeks post training. The results showed that these parameters remained constant. This proved that the proposed system provide substantial support toward the preservation of the Taiwanese older people’ physiological function and standing stability. PMID:27190480

Improvement in the physiological function and standing stability based on kinect multimedia for older people.

PubMed

Chen, Chih-Chen

2016-04-01

[Purpose] The increase in the Taiwanese older population is associated with age-related inconveniences. Finding adequate and simple physical activities to help the older people maintaining their physiological function and preventing them from falls has become an urgent social issue. [Subjects and Methods] This study aimed to design a virtual exercise training game suitable for Taiwanese older people. This system will allow for the maintenance of the physiological function and standing stability through physical exercise, while using a virtual reality game. The participants can easily exercise in a carefree, interactive environment. This study will use Kinect for Windows for physical movement detection and Unity software for virtual world development. [Results] Group A and B subjects were involved in the exercise training method of Kinect interactive multimedia for 12 weeks. The results showed that the functional reach test and the unipedal stance test improved significantly. [Conclusion] The physiological function and standing stability of the group A subjects were examined at six weeks post training. The results showed that these parameters remained constant. This proved that the proposed system provide substantial support toward the preservation of the Taiwanese older people' physiological function and standing stability.

Target Selection for the SDSS-III MARVELS Survey

NASA Astrophysics Data System (ADS)

Paegert, Martin; Stassun, Keivan G.; De Lee, Nathan; Pepper, Joshua; Fleming, Scott W.; Sivarani, Thirupathi; Mahadevan, Suvrath; Mack, Claude E., III; Dhital, Saurav; Hebb, Leslie; Ge, Jian

2015-06-01

We present the target selection process for the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the Sloan Digital Sky Survey (SDSS) III. MARVELS is a medium-resolution (R ∼ 11,000) multi-fiber spectrograph capable of obtaining radial velocities for 60 objects at a time in order to find brown dwarfs and giant planets. The survey was configured to target dwarf stars with effective temperatures approximately between 4500 and 6250 K. For the first 2 years MARVELS relied on low-resolution spectroscopic pre-observations to estimate the effective temperature and log (g) for candidate stars and then selected suitable dwarf stars from this pool. Ultimately, the pre-observation spectra proved ineffective at filtering out giant stars; many giants were incorrectly classified as dwarfs, resulting in a giant contamination rate of ∼30% for the first phase of the MARVELS survey. Thereafter, the survey instead applied a reduced proper motion cut to eliminate giants and used the Infrared Flux Method to estimate effective temperatures, using only extant photmetric and proper-motion catalog information. The target selection method introduced here may be useful for other surveys that need to rely on extant catalog data for selection of specific stellar populations.

Robust Functionalization of Large Microelectrode Arrays by Using Pulsed Potentiostatic Deposition

PubMed Central

Rothe, Joerg; Frey, Olivier; Madangopal, Rajtarun; Rickus, Jenna; Hierlemann, Andreas

2016-01-01

Surface modification of microelectrodes is a central step in the development of microsensors and microsensor arrays. Here, we present an electrodeposition scheme based on voltage pulses. Key features of this method are uniformity in the deposited electrode coatings, flexibility in the overall deposition area, i.e., the sizes and number of the electrodes to be coated, and precise control of the surface texture. Deposition and characterization of four different materials are demonstrated, including layers of high-surface-area platinum, gold, conducting polymer poly(ethylenedioxythiophene), also known as PEDOT, and the non-conducting polymer poly(phenylenediamine), also known as PPD. The depositions were conducted using a fully integrated complementary metal-oxide-semiconductor (CMOS) chip with an array of 1024 microelectrodes. The pulsed potentiostatic deposition scheme is particularly suitable for functionalization of individual electrodes or electrode subsets of large integrated microelectrode arrays: the required deposition waveforms are readily available in an integrated system, the same deposition parameters can be used to functionalize the surface of either single electrodes or large arrays of thousands of electrodes, and the deposition method proved to be robust and reproducible for all materials tested. PMID:28025569

A safe an easy method for building consensus HIV sequences from 454 massively parallel sequencing data.

PubMed

Fernández-Caballero Rico, Jose Ángel; Chueca Porcuna, Natalia; Álvarez Estévez, Marta; Mosquera Gutiérrez, María Del Mar; Marcos Maeso, María Ángeles; García, Federico

2018-02-01

To show how to generate a consensus sequence from the information of massive parallel sequences data obtained from routine HIV anti-retroviral resistance studies, and that may be suitable for molecular epidemiology studies. Paired Sanger (Trugene-Siemens) and next-generation sequencing (NGS) (454 GSJunior-Roche) HIV RT and protease sequences from 62 patients were studied. NGS consensus sequences were generated using Mesquite, using 10%, 15%, and 20% thresholds. Molecular evolutionary genetics analysis (MEGA) was used for phylogenetic studies. At a 10% threshold, NGS-Sanger sequences from 17/62 patients were phylogenetically related, with a median bootstrap-value of 88% (IQR83.5-95.5). Association increased to 36/62 sequences, median bootstrap 94% (IQR85.5-98)], using a 15% threshold. Maximum association was at the 20% threshold, with 61/62 sequences associated, and a median bootstrap value of 99% (IQR98-100). A safe method is presented to generate consensus sequences from HIV-NGS data at 20% threshold, which will prove useful for molecular epidemiological studies. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Decentralized Dimensionality Reduction for Distributed Tensor Data Across Sensor Networks.

PubMed

Liang, Junli; Yu, Guoyang; Chen, Badong; Zhao, Minghua

2016-11-01

This paper develops a novel decentralized dimensionality reduction algorithm for the distributed tensor data across sensor networks. The main contributions of this paper are as follows. First, conventional centralized methods, which utilize entire data to simultaneously determine all the vectors of the projection matrix along each tensor mode, are not suitable for the network environment. Here, we relax the simultaneous processing manner into the one-vector-by-one-vector (OVBOV) manner, i.e., determining the projection vectors (PVs) related to each tensor mode one by one. Second, we prove that in the OVBOV manner each PV can be determined without modifying any tensor data, which simplifies corresponding computations. Third, we cast the decentralized PV determination problem as a set of subproblems with consensus constraints, so that it can be solved in the network environment only by local computations and information communications among neighboring nodes. Fourth, we introduce the null space and transform the PV determination problem with complex orthogonality constraints into an equivalent hidden convex one without any orthogonality constraint, which can be solved by the Lagrange multiplier method. Finally, experimental results are given to show that the proposed algorithm is an effective dimensionality reduction scheme for the distributed tensor data across the sensor networks.

In vivo detection of basal cell carcinoma: comparison of a reflectance confocal microscope and a multiphoton tomograph

NASA Astrophysics Data System (ADS)

Ulrich, Martina; Klemp, Marisa; Darvin, Maxim E.; König, Karsten; Lademann, Jürgen; Meinke, Martina C.

2013-06-01

The standard diagnostic procedure for basal cell carcinoma (BCC) is invasive tissue biopsy with time-consuming histological examination. To reduce the number of biopsies, noninvasive optical methods have been developed providing high-resolution skin examination. We present direct comparison of a reflectance confocal microscope (RLSM) and a multiphoton tomograph (MPT) for BCC diagnosis. Both systems are applied to nine patients prior to surgery, and the results are analyzed, including histological results. Both systems prove suitable for detecting typical characteristics of BCC in various stages. The RLSM allows large horizontal overview images to be obtained, enabling the investigator to find the regions of interest quickly, e.g., BCC nests. Elongated cells and palisading structures are easily recognized using both methods. Due to the higher resolution, changes in nucleus diameter or cytoplasm could be visualized with the MPT. Therefore, the nucleus diameter, nucleus/cytoplasm ratio, and cell density are estimated for normal and BCC cells using the MPT. The nucleus of elongated BCC cells is significantly longer than other measured normal skin cells, whereas the cell density and nucleus/cytoplasm ratio of BCC cannot be significantly distinguished from granular cells.

Analysis of advanced glycation endproducts in selected food items by ultra-performance liquid chromatography tandem mass spectrometry: Presentation of a dietary AGE database.

PubMed

Scheijen, Jean L J M; Clevers, Egbert; Engelen, Lian; Dagnelie, Pieter C; Brouns, Fred; Stehouwer, Coen D A; Schalkwijk, Casper G

2016-01-01

The aim of this study was to validate an ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS) method for the determination of advanced glycation endproducts (AGEs) in food items and to analyze AGEs in a selection of food items commonly consumed in a Western diet. N(ε)-(carboxymethyl)lysine (CML), N(ε)-(1-carboxyethyl)lysine (CEL) and N(δ)-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were quantified in the protein fractions of 190 food items using UPLC-MS/MS. Intra- and inter-day accuracy and precision were 2-29%. The calibration curves showed perfect linearity in water and food matrices. We found the highest AGE levels in high-heat processed nut or grain products, and canned meats. Fruits, vegetables, butter and coffee had the lowest AGE content. The described method proved to be suitable for the quantification of three major AGEs in food items. The presented dietary AGE database opens the possibility to further quantify actual dietary exposure to AGEs and to explore its physiological impact on human health. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Development of the Problematic Online Gaming Questionnaire (POGQ)

PubMed Central

Demetrovics, Zsolt; Urbán, Róbert; Nagygyörgy, Katalin; Farkas, Judit; Griffiths, Mark D.; Pápay, Orsolya; Kökönyei, Gyöngyi; Felvinczi, Katalin; Oláh, Attila

2012-01-01

Background Online gaming has become increasingly popular. However, this has led to concerns that these games might induce serious problems and/or lead to dependence for a minority of players. Aim: The aim of this study was to uncover and operationalize the components of problematic online gaming. Methods A total of 3415 gamers (90% males; mean age 21 years), were recruited through online gaming websites. A combined method of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) was applied. Latent profile analysis was applied to identify persons at-risk. Results EFA revealed a six-factor structure in the background of problematic online gaming that was also confirmed by a CFA. For the assessment of the identified six dimensions – preoccupation, overuse, immersion, social isolation, interpersonal conflicts, and withdrawal – the 18-item Problematic Online Gaming Questionnaire (POGQ) proved to be exceedingly suitable. Based on the latent profile analysis, 3.4% of the gamer population was considered to be at high risk, while another 15.2% was moderately problematic. Conclusions The POGQ seems to be an adequate measurement tool for the differentiated assessment of gaming related problems on six subscales. PMID:22590541

Mechanical Properties of Laser Beam Welded Ultra-high Strength Chromium Steel with Martensitic Microstructure

NASA Astrophysics Data System (ADS)

Dahmen, Martin; Janzen, Vitalij; Lindner, Stefan; Wagener, Rainer

A new class of steels is going to be introduced into sheet manufacturing. Stainless ferritic and martensitic steels open up opportunities for sheet metal fabrication including hot stamping. A strength of up to 2 GPa at a fracture strain of 15% can be attained. Welding of these materials became apparently a challenge. Energy-reduced welding methods with in-situ heat treatment are required in order to ensure the delicate and complex heat control. Laser beam welding is the joining technique of choice to supply minimum heat input to the fusion process and to apply an efficient heat control. For two application cases, production of tailored blanks in as-rolled condition and welding in assembly in hot stamped conditions, welding processes have been developed. The welding suitability is shown in metallurgical investigations of the welds. Crash tests based on the KSII concept as well as fatigue tests prove the applicability of the joining method. For the case of assembly also joining with deep drawing and manganese boron steel was taken into consideration. The strength of the joint is determined by the weaker partner but can benefit from its ductility.

Enantioselective separation of biologically active basic compounds in ultra-performance supercritical fluid chromatography.

PubMed

Geryk, Radim; Kalíková, Květa; Schmid, Martin G; Tesařová, Eva

2016-08-17

The enantioseparation of basic compounds represent a challenging task in modern SFC. Therefore this work is focused on development and optimization of fast SFC methods suitable for enantioseparation of 27 biologically active basic compounds of various structures. The influences of the co-solvent type as well as different mobile phase additives on retention, enantioselectivity and enantioresolution were investigated. Obtained results confirmed that the mobile phase additives, especially bases (or the mixture of base and acid), improve peak shape and enhance enantioresolution. The best results were achieved with isopropylamine or the mixture of isopropylamine and trifluoroacetic acid as additives. In addition, the effect of temperature and back pressure were evaluated to optimize the enantioseparation process. The immobilized amylose-based chiral stationary phase, i.e. tris(3,5-dimethylphenylcarbamate) derivative of amylose proved to be useful tool for the enantioseparation of a broad spectrum of chiral bases. The chromatographic conditions that yielded baseline enantioseparations of all tested compounds were discovered. The presented work can serve as a guide for simplifying the method development for enantioseparation of basic racemates in SFC. Copyright © 2016 Elsevier B.V. All rights reserved.

Temperature changes in brown adipocytes detected with a bimaterial microcantilever.

PubMed

Sato, Masaaki K; Toda, Masaya; Inomata, Naoki; Maruyama, Hisataka; Okamatsu-Ogura, Yuko; Arai, Fumihito; Ono, Takahito; Ishijima, Akihiko; Inoue, Yuichi

2014-06-03

Mammalian cells must produce heat to maintain body temperature and support other biological activities. Methods to measure a cell's thermogenic ability by inserting a thermometer into the cell or measuring the rate of oxygen consumption in a closed vessel can disturb its natural state. Here, we developed a noninvasive system for measuring a cell's heat production with a bimaterial microcantilever. This method is suitable for investigating the heat-generating properties of cells in their native state, because changes in cell temperature can be measured from the bending of the microcantilever, without damaging the cell and restricting its supply of dissolved oxygen. Thus, we were able to measure increases in cell temperature of <1 K in a small number of murine brown adipocytes (n = 4-7 cells) stimulated with norepinephrine, and observed a slow increase in temperature over several hours. This long-term heat production suggests that, in addition to converting fatty acids into heat energy, brown adipocytes may also adjust protein expression to raise their own temperature, to generate more heat. We expect this bimaterial microcantilever system to prove useful for determining a cell's state by measuring thermal characteristics. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Investigation of temperature-dependent photoluminescence in multi-quantum wells.

PubMed

Fang, Yutao; Wang, Lu; Sun, Qingling; Lu, Taiping; Deng, Zhen; Ma, Ziguang; Jiang, Yang; Jia, Haiqiang; Wang, Wenxin; Zhou, Junming; Chen, Hong

2015-07-31

Photoluminescence (PL) is a nondestructive and powerful method to investigate carrier recombination and transport characteristics in semiconductor materials. In this study, the temperature dependences of photoluminescence of GaAs-AlxGa1-xAs multi-quantum wells samples with and without p-n junction were measured under both resonant and non-resonant excitation modes. An obvious increase of photoluminescence(PL) intensity as the rising of temperature in low temperature range (T < 50 K), is observed only for GaAs-AlxGa1-xAs quantum wells sample with p-n junction under non-resonant excitation. The origin of the anomalous increase of integrated PL intensity proved to be associated with the enhancement of carrier drifting because of the increase of carrier mobility in the temperature range from 15 K to 100 K. For non-resonant excitation, carriers supplied from the barriers will influence the temperature dependence of integrated PL intensity of quantum wells, which makes the traditional methods to acquire photoluminescence characters from the temperature dependence of integrated PL intensity unavailable. For resonant excitation, carriers are generated only in the wells and the temperature dependence of integrated PL intensity is very suitable to analysis the photoluminescence characters of quantum wells.

Utilising three-dimensional printing techniques when providing unique assistive devices: A case report.

PubMed

Day, Sarah Jane; Riley, Shaun Patrick

2018-02-01

The evolution of three-dimensional printing into prosthetics has opened conversations about the availability and cost of prostheses. This report will discuss how a prosthetic team incorporated additive manufacture techniques into the treatment of a patient with a partial hand amputation to create and test a unique assistive device which he could use to hold his French horn. Case description and methods: Using a process of shape capture, photogrammetry, computer-aided design and finite element analysis, a suitable assistive device was designed and tested. The design was fabricated using three-dimensional printing. Patient satisfaction was measured using a Pugh's Matrix™, and a cost comparison was made between the process used and traditional manufacturing. Findings and outcomes: Patient satisfaction was high. The three-dimensional printed devices were 56% cheaper to fabricate than a similar laminated device. Computer-aided design and three-dimensional printing proved to be an effective method for designing, testing and fabricating a unique assistive device. Clinical relevance CAD and 3D printing techniques can enable devices to be designed, tested and fabricated cheaper than when using traditional techniques. This may lead to improvements in quality and accessibility.

Key Technologies and Applications of Gas Drainage in Underground Coal Mine

NASA Astrophysics Data System (ADS)

Zhou, Bo; Xue, Sheng; Cheng, Jiansheng; Li, Wenquan; Xiao, Jiaping

2018-02-01

It is the basis for the long-drilling directional drilling, precise control of the drilling trajectory and ensuring the effective extension of the drilling trajectory in the target layer. The technology can be used to complete the multi-branch hole construction and increase the effective extraction distance of the coal seam. The gas drainage and the bottom grouting reinforcement in the advanced area are realized, and the geological structure of the coal seam can be proved accurately. It is the main technical scheme for the efficient drainage of gas at home and abroad, and it is applied to the field of geological structure exploration and water exploration and other areas. At present, the data transmission method is relatively mature in the technology and application, including the mud pulse and the electromagnetic wave. Compared with the mud pulse transmission mode, the electromagnetic wave transmission mode has obvious potential in the data transmission rate and drilling fluid, and it is suitable for the coal mine. In this paper, the key technologies of the electromagnetic wave transmission mode are analyzed, including the attenuation characteristics of the electromagnetic transmission channel, the digital modulation scheme, the channel coding method and the weak signal processing technology. A coal mine under the electromagnetic wave drilling prototype is developed, and the ground transmission experiments and down hole transmission test are carried out. The main work includes the following aspects. First, the equivalent transmission line method is used to establish the electromagnetic transmission channel model of coal mine drilling while drilling, and the attenuation of the electromagnetic signal is measured when the electromagnetic channel measured. Second, the coal mine EM-MWD digital modulation method is developed. Third, the optimal linear block code which suitable for EM-MWD communication channel in coal mine is proposed. Fourth, the noise characteristics of well near horizontal directional drilling are analyzed, and the multi-stage filter method is proposed to suppress the natural potential and strong frequency interference signal. And the weak electromagnetic communication signal is extracted from the received signal. Finally, the detailed design of the electromagnetic wave while drilling is given.

A Validated Method for the Quality Control of Andrographis paniculata Preparations.

PubMed

Karioti, Anastasia; Timoteo, Patricia; Bergonzi, Maria Camilla; Bilia, Anna Rita

2017-10-01

Andrographis paniculata is a herbal drug of Asian traditional medicine largely employed for the treatment of several diseases. Recently, it has been introduced in Europe for the prophylactic and symptomatic treatment of common cold and as an ingredient of dietary supplements. The active principles are diterpenes with andrographolide as the main representative. In the present study, an analytical protocol was developed for the determination of the main constituents in the herb and preparations of A. paniculata . Three different extraction protocols (methanol extraction using a modified Soxhlet procedure, maceration under ultrasonication, and decoction) were tested. Ultrasonication achieved the highest content of analytes. HPLC conditions were optimized in terms of solvent mixtures, time course, and temperature. A reversed phase C18 column eluted with a gradient system consisting of acetonitrile and acidified water and including an isocratic step at 30 °C was used. The HPLC method was validated for linearity, limits of quantitation and detection, repeatability, precision, and accuracy. The overall method was validated for precision and accuracy over at least three different concentration levels. Relative standard deviation was less than 1.13%, whereas recovery was between 95.50% and 97.19%. The method also proved to be suitable for the determination of a large number of commercial samples and was proposed to the European Pharmacopoeia for the quality control of Andrographidis herba. Georg Thieme Verlag KG Stuttgart · New York.

Multi-axis control based on movement control cards in NC systems

NASA Astrophysics Data System (ADS)

Jiang, Tingbiao; Wei, Yunquan

2005-12-01

Today most movement control cards need special control software of topper computers and are only suitable for fixed-axis controls. Consequently, the number of axes which can be controlled is limited. Advanced manufacture technology develops at a very high speed, and that development brings forth. New requirements for movement control in mechanisms and electronics. This paper introduces products of the 5th generation of movement control cards, PMAC 2A-PC/104, made by the Delta Tau Company in the USA. Based on an analysis of PMAC 2A-PC/104, this paper first describes two aspects relevant to the hardware structure of movement control cards and the interrelated software of the topper computers. Then, two methods are presented for solving these problems. The first method is to set limit switches on the movement control cards; all of them can be used to control each moving axis. The second method is to program applied software with existing programming language (for example, VC ++, Visual Basic, Delphi, and so forth). This program is much easier to operate and expand by its users. By using a limit switch, users can choose different axes in movement control cards. Also, users can change parts of the parameters in the control software of topper computers to realize different control axes. Combining these 2 methods proves to be convenient for realizing multi-axis control in numerical control systems.

Validation of the analytical method for the simultaneous determination of selected polybrominated diphenyl ethers, polychlorinated biphenyls and organochlorine pesticides in human blood serum by gas chromatography with microelectron capture detector.

PubMed

Matuszak, Małgorzata; Minorczyk, Maria; Góralczyk, Katarzyna; Hernik, Agnieszka; Struciński, Paweł; Liszewska, Monika; Czaja, Katarzyna; Korcz, Wojciech; Łyczewska, Monika; Ludwicki, Jan K

2016-01-01

Polybrominated diphenyl ethers (PBDEs) as other persistent organic pollutants like polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) pose a significant hazard to human health, mainly due to interference with the endocrine system and carcinogenetic effects. Humans are exposed to these substances mainly through a food of animal origin. These pollutants are globally detected in human matrices which requires to dispose reliable and simple analytical method that would enable further studies to assess the exposure of specific human populations to these compounds. The purpose of this study was to modify and validate of the analytical procedure for the simultaneous determination of selected PBDEs, PCBs and OCPs in human blood serum samples. The analytical measurement was performed by GC-µECD following preparation of serum samples (denaturation, multiple extraction, lipid removal). Identity of the compounds was confirmed by GC-MS. The method was characterised by the appropriate linearity, good repeatability (CV below 20%). The recoveries ranged from 52.9 to 125.0% depending on compound and level of fortification. The limit of quantification was set at 0.03 ng mL(-1) of serum. The modified analytical method proved to be suitable for the simultaneous determination of selected PBDEs, PCBs and OCPs in human blood serum by GC-µECD with good precision.

A flexible-dose dispenser for immediate and extended release 3D printed tablets.

PubMed

Pietrzak, Katarzyna; Isreb, Abdullah; Alhnan, Mohamed A

2015-10-01

The advances in personalised medicine increased the demand for a fast, accurate and reliable production method of tablets that can be digitally controlled by healthcare staff. A flexible dose tablet system is presented in this study that proved to be suitable for immediate and extended release tablets with a realistic drug loading and an easy-to-swallow tablet design. The method bridges the affordable and digitally controlled Fused Deposition Modelling (FDM) 3D printing with a standard pharmaceutical manufacturing process, Hot Melt Extrusion (HME). The reported method was compatible with three methacrylic polymers (Eudragit RL, RS and E) as well as a cellulose-based one (hydroxypropyl cellulose, HPC SSL). The use of a HME based pharmaceutical filament preserved the linear relationship between the mass and printed volume and was utilized to digitally control the dose via an input from computer software with dose accuracy in the range of 91-95%. Higher resolution printing quality doubled the printing time, but showed a little effect on in vitro release pattern of theophylline and weight accuracy. Physical characterization studies indicated that the majority of the model drug (theophylline) in the 3D printed tablet exists in a crystal form. Owing to the small size, ease of use and the highly adjustable nature of FDM 3D printers, the method holds promise for future individualised treatment. Copyright © 2015. Published by Elsevier B.V.

High-efficiency non-uniformity correction for wide dynamic linear infrared radiometry system

NASA Astrophysics Data System (ADS)

Li, Zhou; Yu, Yi; Tian, Qi-Jie; Chang, Song-Tao; He, Feng-Yun; Yin, Yan-He; Qiao, Yan-Feng

2017-09-01

Several different integration times are always set for a wide dynamic linear and continuous variable integration time infrared radiometry system, therefore, traditional calibration-based non-uniformity correction (NUC) are usually conducted one by one, and furthermore, several calibration sources required, consequently makes calibration and process of NUC time-consuming. In this paper, the difference of NUC coefficients between different integration times have been discussed, and then a novel NUC method called high-efficiency NUC, which combines the traditional calibration-based non-uniformity correction, has been proposed. It obtains the correction coefficients of all integration times in whole linear dynamic rangesonly by recording three different images of a standard blackbody. Firstly, mathematical procedure of the proposed non-uniformity correction method is validated and then its performance is demonstrated by a 400 mm diameter ground-based infrared radiometry system. Experimental results show that the mean value of Normalized Root Mean Square (NRMS) is reduced from 3.78% to 0.24% by the proposed method. In addition, the results at 4 ms and 70 °C prove that this method has a higher accuracy compared with traditional calibration-based NUC. In the meantime, at other integration time and temperature there is still a good correction effect. Moreover, it greatly reduces the number of correction time and temperature sampling point, and is characterized by good real-time performance and suitable for field measurement.

Liquid paraffin as new dilution medium for the analysis of high boiling point residual solvents with static headspace-gas chromatography.

PubMed

D'Autry, Ward; Zheng, Chao; Bugalama, John; Wolfs, Kris; Hoogmartens, Jos; Adams, Erwin; Wang, Bochu; Van Schepdael, Ann

2011-07-15

Residual solvents are volatile organic compounds which can be present in pharmaceutical substances. A generic static headspace-gas chromatography analysis method for the identification and control of residual solvents is described in the European Pharmacopoeia. Although this method is proved to be suitable for the majority of samples and residual solvents, the method may lack sensitivity for high boiling point residual solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide and benzyl alcohol. In this study, liquid paraffin was investigated as new dilution medium for the analysis of these residual solvents. The headspace-gas chromatography method was developed and optimized taking the official Pharmacopoeia method as a starting point. The optimized method was validated according to ICH criteria. It was found that the detection limits were below 1μg/vial for each compound, indicating a drastically increased sensitivity compared to the Pharmacopoeia method, which failed to detect the compounds at their respective limit concentrations. Linearity was evaluated based on the R(2) values, which were above 0.997 for all compounds, and inspection of residual plots. Instrument and method precision were examined by calculating the relative standard deviations (RSD) of repeated analyses within the linearity and accuracy experiments, respectively. It was found that all RSD values were below 10%. Accuracy was checked by a recovery experiment at three different levels. Mean recovery values were all in the range 95-105%. Finally, the optimized method was applied to residual DMSO analysis in four different Kollicoat(®) sample batches. Copyright © 2011 Elsevier B.V. All rights reserved.

Zonal assessment of environmental driven settlement abandonment in the Trans-Tisza region (Central Europe) during the early phase of the Little Ice Age

NASA Astrophysics Data System (ADS)

Pinke, Zsolt; Ferenczi, László; F. Romhányi, Beatrix; Gyulai, Ferenc; Laszlovszky, József; Mravcsik, Zoltán; Pósa, Patricia; Gábris, Gyula

2017-02-01

This investigation focuses on the transformation of the settlement pattern of a lowland landscape as a social response to the hydrological challenges emerging in the late 13th century (c.) overture of the Little Ice Age (LIA). Results of the applied zonal analysis suggested a strong spatial connection between the geomorphological conditions, the agro-ecological suitability (good-excellent, medium and low) and the stability or instability of settlement patterns. The elevation means of archaeological sites in the deserted zones proved significantly lower than those in zones with permanent settlement pattern (Brunner-Munzel test p ≤ 0.01; n = 377). Additionally, the late medieval (14th-mid-16th centuries) site group was situated, on average, significantly higher than the high medieval (late 10th-13th centuries) site group within the permanent zones (Brunner-Munzel test p ≤ 0.01; n = 219). These outcomes statistically confirm that not only did low-lying inhabited areas shrink significantly, but they also displaced vertically in the first phase of the LIA. When analysing the relation of settlement pattern to soil conditions, the proportion of areas with good-excellent agro-ecological suitability proved 1.5-2 times higher in the permanent zones than in the deserted and uninhabited settlement suitability zones. Using the linear model, different regression coefficients appeared between the extension of the high and medium agro-ecological suitability zones and the number of high and late medieval settlements. The different coefficients in the studied two periods suggest that the issue of agroecological suitability in the High Middle Ages did not bear such importance as in the late Middle Ages. The findings of the paper may contribute to answering the question why the relatively dense settlement pattern of the deserted zones was abandoned almost completely by the end of the 13th c. in areas where flood proneness and weak agro-ecological suitability both meant a serious risk for human communities. Finally, we presumed that if hydro-climatic changes increased water levels, they must have changed the plant composition of the studied landscape as well. Chi-squared test of macrofossil plant remains (narchaeological site = 55; ntaxon = 330) shows that the second part of the 13th c. saw the ratio of species from humid habitat types grow (Χ² = 7.81; df = 1; p = 0.02). Comparison of the two studied processes indicates a broad synchronism between the shrinkage of inhabited areas and the increasing proportion of plants with humid environment tolerance during the second part of the 13th c. The reconstructed transformations in the composition of plant remains and settlement structure signal not a mere transitional change, but a 'longue durée' structural transformation of the landscape.

Aluminium, gallium, and molybdenum toxicity to the tropical marine microalga Isochrysis galbana.

PubMed

Trenfield, Melanie A; van Dam, Joost W; Harford, Andrew J; Parry, David; Streten, Claire; Gibb, Karen; van Dam, Rick A

2015-08-01

There is a shortage of established chronic toxicity test methods for assessing the toxicity of contaminants to tropical marine organisms. The authors tested the suitability of the tropical microalga Isochrysis galbana for use in routine ecotoxicology and assessed the effects of 72-h exposures to copper (Cu, a reference toxicant), aluminium (Al), gallium (Ga), and molybdenum (Mo), key metals of alumina refinery discharge, on the growth of I. galbana at 3 temperatures: 24 °C, 28 °C, and 31 °C. The sensitivity of both I. galbana and the test method was validated by the response to Cu exposure, with 10% and 50% effect concentrations (EC10 and EC50) of 2.5 μg/L and 18 μg/L, respectively. The EC10 and EC50 values for total Al at 28 °C were 640 μg/L and 3045 μg/L, respectively. The toxicity of both Cu and Al at 24 °C and 31 °C was similar to that at 28 °C. There was no measurable toxicity from dissolved Ga exposures of up to 6000 μg/L or exposures to dissolved Mo of up to 9500 μg/L. Solubility limits at 28 °C for the dissolved fractions (<10 kDa) of Al, Ga, and Mo were approximately 650 μg/L Al, >7000 μg/L Ga, and >6000 μg/L Mo. In test solutions containing >650 μg/L total Al, dissolved and precipitated forms of Al were present, with precipitated Al becoming more dominant as total Al increased. The test method proved suitable for routine ecotoxicology, with I. galbana showing sensitivity to Cu but Al, Ga, and Mo exhibiting little to no toxicity to this species. © 2015 SETAC.

Novel application of explicit dynamics occupancy models to ongoing aquatic invasions

USGS Publications Warehouse

Sepulveda, Adam J.

2018-01-01

Identification of suitable habitats, where invasive species can establish, is an important step towards controlling their spread. Accurate identification is difficult for new or slow invaders because unoccupied habitats may be suitable, given enough time for dispersal, while occupied habitats may prove to be unsuitable for establishment.To identify the suitable habitat of a recent invader, I used an explicit dynamics occupancy modelling framework to evaluate habitat covariates related to successful and failed establishments of American bullfrogs (Lithobates catesbeianus) within the Yellowstone River floodplain of Montana, USA from 2012-2016.During this five-year period, bullfrogs failed to establish at most sites they colonized. Bullfrog establishment was most likely to occur and least likely to fail at sites closest to human-modified ponds and lakes and those with emergent vegetation. These habitat covariates were generally associated with the presence of permanent water.Suitable habitat for bullfrog establishment is abundant in the Yellowstone River floodplain, though many sites with suitable habitat remain uncolonized. Thus, the maximum distribution of bullfrogs is much greater than their current distribution.Synthesis and applications. Focused control efforts on habitats with or proximate to permanent waters are most likely to reduce the potential for invasive bullfrog establishment and spread in the Yellowstone River. The novel application of explicit dynamics occupancy models is a useful and widely applicable tool for guiding management efforts towards those habitats where new or slow invaders are most likely to establish and persist.

Aerodynamic shape optimization using control theory

NASA Technical Reports Server (NTRS)

Reuther, James

1996-01-01

Aerodynamic shape design has long persisted as a difficult scientific challenge due its highly nonlinear flow physics and daunting geometric complexity. However, with the emergence of Computational Fluid Dynamics (CFD) it has become possible to make accurate predictions of flows which are not dominated by viscous effects. It is thus worthwhile to explore the extension of CFD methods for flow analysis to the treatment of aerodynamic shape design. Two new aerodynamic shape design methods are developed which combine existing CFD technology, optimal control theory, and numerical optimization techniques. Flow analysis methods for the potential flow equation and the Euler equations form the basis of the two respective design methods. In each case, optimal control theory is used to derive the adjoint differential equations, the solution of which provides the necessary gradient information to a numerical optimization method much more efficiently then by conventional finite differencing. Each technique uses a quasi-Newton numerical optimization algorithm to drive an aerodynamic objective function toward a minimum. An analytic grid perturbation method is developed to modify body fitted meshes to accommodate shape changes during the design process. Both Hicks-Henne perturbation functions and B-spline control points are explored as suitable design variables. The new methods prove to be computationally efficient and robust, and can be used for practical airfoil design including geometric and aerodynamic constraints. Objective functions are chosen to allow both inverse design to a target pressure distribution and wave drag minimization. Several design cases are presented for each method illustrating its practicality and efficiency. These include non-lifting and lifting airfoils operating at both subsonic and transonic conditions.

Soy-based fillers for thermoset composites

NASA Astrophysics Data System (ADS)

Watt, Paula

Considerable work has been done with bio-based fillers in thermoplastics. Wood dust has been used for decades in wood plastic composites in conjunction with recycled high HDPE and PET. In recent years rapidly renewable fillers derived from dried distillery grains and from wood have been introduced commercially for thermoset polymers. These fillers provide bio-content and weight reduction to thermoset molding compounds but issues with moisture absorption and polymerization inhibition have limited their commercial acceptance. The intent of this research was to develop a bio-based filler suitable for thermoset composites. This filler would provide a low density alternative to mined mineral filler, such as CaCO3 or clay. Composites made with these fillers would be lighter in weight, which is desirable for many markets, particularly transportation. Cost parity to the mineral fillers, on a volume basis, was desirable and the use of green chemistry principles was a key objective of the project. This work provides a basis from which further development of modified soy flours as fillers for thermoset composites will continue. Biomass has been evaluated as fillers for thermoset composites since the early 1980s but failed to gain commercial acceptance due to excessive water absorption and inhibition issues with free radical curing. Biomass, with a large percentage of carbohydrates, are very hydrophilic due to their abundance of hydroxyl groups, while biomass, high in lignin, resulted in inhibition of the free radical cure of the unsaturated styrenated polyester matrix systems. Generally protein use as a filler is not desirable due to its food value. Torrefaction has proved to be a good, cost effective, process to reduce hydrophilicity of high cellulose feedstock. Surprising, however, some levels of torrefaction were found to induce the inhibition effect of the filler. Scientific inquiry into this problem proved that aromatics form during the torrefaction process and can become problematic when threshold levels are reached. Studies to determine suitable levels and appropriate processes provided options for manufacture of suitable fillers.

Flexible ultrathin-body single-photon avalanche diode sensors and CMOS integration.

PubMed

Sun, Pengfei; Ishihara, Ryoichi; Charbon, Edoardo

2016-02-22

We proposed the world's first flexible ultrathin-body single-photon avalanche diode (SPAD) as photon counting device providing a suitable solution to advanced implantable bio-compatible chronic medical monitoring, diagnostics and other applications. In this paper, we investigate the Geiger-mode performance of this flexible ultrathin-body SPAD comprehensively and we extend this work to the first flexible SPAD image sensor with in-pixel and off-pixel electronics integrated in CMOS. Experimental results show that dark count rate (DCR) by band-to-band tunneling can be reduced by optimizing multiplication doping. DCR by trap-assisted avalanche, which is believed to be originated from the trench etching process, could be further reduced, resulting in a DCR density of tens to hundreds of Hertz per micrometer square at cryogenic temperature. The influence of the trench etching process onto DCR is also proved by comparison with planar ultrathin-body SPAD structures without trench. Photon detection probability (PDP) can be achieved by wider depletion and drift regions and by carefully optimizing body thickness. PDP in frontside- (FSI) and backside-illumination (BSI) are comparable, thus making this technology suitable for both modes of illumination. Afterpulsing and crosstalk are negligible at 2µs dead time, while it has been proved, for the first time, that a CMOS SPAD pixel of this kind could work in a cryogenic environment. By appropriate choice of substrate, this technology is amenable to implantation for biocompatible photon-counting applications and wherever bended imaging sensors are essential.

Central Limit Theorem for Exponentially Quasi-local Statistics of Spin Models on Cayley Graphs

NASA Astrophysics Data System (ADS)

Reddy, Tulasi Ram; Vadlamani, Sreekar; Yogeshwaran, D.

2018-04-01

Central limit theorems for linear statistics of lattice random fields (including spin models) are usually proven under suitable mixing conditions or quasi-associativity. Many interesting examples of spin models do not satisfy mixing conditions, and on the other hand, it does not seem easy to show central limit theorem for local statistics via quasi-associativity. In this work, we prove general central limit theorems for local statistics and exponentially quasi-local statistics of spin models on discrete Cayley graphs with polynomial growth. Further, we supplement these results by proving similar central limit theorems for random fields on discrete Cayley graphs taking values in a countable space, but under the stronger assumptions of α -mixing (for local statistics) and exponential α -mixing (for exponentially quasi-local statistics). All our central limit theorems assume a suitable variance lower bound like many others in the literature. We illustrate our general central limit theorem with specific examples of lattice spin models and statistics arising in computational topology, statistical physics and random networks. Examples of clustering spin models include quasi-associated spin models with fast decaying covariances like the off-critical Ising model, level sets of Gaussian random fields with fast decaying covariances like the massive Gaussian free field and determinantal point processes with fast decaying kernels. Examples of local statistics include intrinsic volumes, face counts, component counts of random cubical complexes while exponentially quasi-local statistics include nearest neighbour distances in spin models and Betti numbers of sub-critical random cubical complexes.

Biocide leaching during field experiments on treated articles.

PubMed

Schoknecht, Ute; Mathies, Helena; Wegner, Robby

2016-01-01

Biocidal products can be sources of active substances in surface waters caused by weathering of treated articles. Marketing and use of biocidal products can be limited according to the European Biocidal Products Regulation if unacceptable risks to the environment are expected. Leaching of active substances from treated articles was observed in field experiments to obtain information on leaching processes and investigate the suitability of a proposed test method. Leaching under weathering conditions proceeds discontinuously and tends to decrease with duration of exposure. It does not only mainly depend on the availability of water but is also controlled by transport processes within the materials and stability of the observed substances. Runoff amount proved to be a suitable basis to compare results from different experiments. Concentrations of substances are higher in runoff collected from vertical surfaces compared to horizontal ones, whereas the leached amounts per surface area are higher from horizontal surfaces. Gaps in mass balances indicate that additional processes such as degradation and evaporation may be relevant to the fate of active substances in treated articles. Leached amounts of substances were considerably higher when the materials were exposed to intermittent water contact under laboratory conditions as compared to weathering of vertically exposed surfaces. Experiences from the field experiments were used to define parameters of a procedure that is now provided to fulfil the requirements of the Biocidal Products Regulation. The experiments confirmed that the amount of water which is in contact with exposed surfaces is the crucial parameter determining leaching of substances.

Compressive properties of commercially available polyurethane foams as mechanical models for osteoporotic human cancellous bone

PubMed Central

Patel, Purvi SD; Shepherd, Duncan ET; Hukins, David WL

2008-01-01

Background Polyurethane (PU) foam is widely used as a model for cancellous bone. The higher density foams are used as standard biomechanical test materials, but none of the low density PU foams are universally accepted as models for osteoporotic (OP) bone. The aim of this study was to determine whether low density PU foam might be suitable for mimicking human OP cancellous bone. Methods Quasi-static compression tests were performed on PU foam cylinders of different lengths (3.9 and 7.7 mm) and of different densities (0.09, 0.16 and 0.32 g.cm-3), to determine the Young's modulus, yield strength and energy absorbed to yield. Results Young's modulus values were 0.08–0.93 MPa for the 0.09 g.cm-3 foam and from 15.1–151.4 MPa for the 0.16 and 0.32 g.cm-3 foam. Yield strength values were 0.01–0.07 MPa for the 0.09 g.cm-3 foam and from 0.9–4.5 MPa for the 0.16 and 0.32 g.cm-3 foam. The energy absorbed to yield was found to be negligible for all foam cylinders. Conclusion Based on these results, it is concluded that 0.16 g.cm-3 PU foam may prove to be suitable as an OP cancellous bone model when fracture stress, but not energy dissipation, is of concern. PMID:18844988

Maximum likelihood estimation of protein kinetic parameters under weak assumptions from unfolding force spectroscopy experiments

NASA Astrophysics Data System (ADS)

Aioanei, Daniel; Samorì, Bruno; Brucale, Marco

2009-12-01

Single molecule force spectroscopy (SMFS) is extensively used to characterize the mechanical unfolding behavior of individual protein domains under applied force by pulling chimeric polyproteins consisting of identical tandem repeats. Constant velocity unfolding SMFS data can be employed to reconstruct the protein unfolding energy landscape and kinetics. The methods applied so far require the specification of a single stretching force increase function, either theoretically derived or experimentally inferred, which must then be assumed to accurately describe the entirety of the experimental data. The very existence of a suitable optimal force model, even in the context of a single experimental data set, is still questioned. Herein, we propose a maximum likelihood (ML) framework for the estimation of protein kinetic parameters which can accommodate all the established theoretical force increase models. Our framework does not presuppose the existence of a single force characteristic function. Rather, it can be used with a heterogeneous set of functions, each describing the protein behavior in the stretching time range leading to one rupture event. We propose a simple way of constructing such a set of functions via piecewise linear approximation of the SMFS force vs time data and we prove the suitability of the approach both with synthetic data and experimentally. Additionally, when the spontaneous unfolding rate is the only unknown parameter, we find a correction factor that eliminates the bias of the ML estimator while also reducing its variance. Finally, we investigate which of several time-constrained experiment designs leads to better estimators.

Validation of 3D multimodality roadmapping in interventional neuroradiology

NASA Astrophysics Data System (ADS)

Ruijters, Daniel; Homan, Robert; Mielekamp, Peter; van de Haar, Peter; Babic, Drazenko

2011-08-01

Three-dimensional multimodality roadmapping is entering clinical routine utilization for neuro-vascular treatment. Its purpose is to navigate intra-arterial and intra-venous endovascular devices through complex vascular anatomy by fusing pre-operative computed tomography (CT) or magnetic resonance (MR) with the live fluoroscopy image. The fused image presents the real-time position of the intra-vascular devices together with the patient's 3D vascular morphology and its soft-tissue context. This paper investigates the effectiveness, accuracy, robustness and computation times of the described methods in order to assess their suitability for the intended clinical purpose: accurate interventional navigation. The mutual information-based 3D-3D registration proved to be of sub-voxel accuracy and yielded an average registration error of 0.515 mm and the live machine-based 2D-3D registration delivered an average error of less than 0.2 mm. The capture range of the image-based 3D-3D registration was investigated to characterize its robustness, and yielded an extent of 35 mm and 25° for >80% of the datasets for registration of 3D rotational angiography (3DRA) with CT, and 15 mm and 20° for >80% of the datasets for registration of 3DRA with MR data. The image-based 3D-3D registration could be computed within 8 s, while applying the machine-based 2D-3D registration only took 1.5 µs, which makes them very suitable for interventional use.

10 CFR 963.16 - Postclosure suitability evaluation method.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 963.16 Energy DEPARTMENT OF ENERGY YUCCA MOUNTAIN SITE SUITABILITY GUIDELINES Site Suitability... assessment to evaluate the ability of the Yucca Mountain disposal system to limit radiological doses and... the performance of the Yucca Mountain disposal system using the method described in paragraph (b) of...

Methodological comparison of alpine meadow evapotranspiration on the Tibetan Plateau, China.

PubMed

Chang, Yaping; Wang, Jie; Qin, Dahe; Ding, Yongjian; Zhao, Qiudong; Liu, Fengjing; Zhang, Shiqiang

2017-01-01

Estimation of evapotranspiration (ET) for alpine meadow areas in the Tibetan Plateau (TP) is essential for water resource management. However, observation data has been limited due to the extreme climates and complex terrain of this region. To address these issues, four representative methods, Penman-Monteith (PM), Priestley-Taylor (PT), Hargreaves-Samani (HS), and Mahringer (MG) methods, were adopted to estimate ET, which were then compared with ET measured using Eddy Covariance (EC) for five alpine meadow sites during the growing seasons from 2010 to 2014. And each site was measured for one growing season during this period. The results demonstrate that the PT method outperformed at all sites with a coefficient of determination (R2) ranging from 0.76 to 0.94 and root mean square error (RMSE) ranging from 0.41 to 0.62 mm d-1. The PM method showed better performance than HS and MG methods, and the HS method produced relatively acceptable results with higher R2 (0.46) and lower RMSE (0.89 mm d-1) compared to MG method with R2 of 0.16 and RMSE of 1.62 mm d-1, while MG underestimated ET at all alpine meadow sites. Therefore, the PT method, being the simpler approach and less data dependent, is recommended to estimate ET for alpine meadow areas in the Tibetan Plateau. The PM method produced reliable results when available data were sufficient, and the HS method proved to be a complementary method when variables were insufficient. On the contrary, the MG method always underestimated ET and is, thus, not suitable for alpine meadows. These results provide a basis for estimating ET on the Tibetan Plateau for annual data collection, analysis, and future studies.

Methodological comparison of alpine meadow evapotranspiration on the Tibetan Plateau, China

PubMed Central

Chang, Yaping; Wang, Jie; Qin, Dahe; Ding, Yongjian; Zhao, Qiudong; Liu, Fengjing

2017-01-01

Estimation of evapotranspiration (ET) for alpine meadow areas in the Tibetan Plateau (TP) is essential for water resource management. However, observation data has been limited due to the extreme climates and complex terrain of this region. To address these issues, four representative methods, Penman-Monteith (PM), Priestley-Taylor (PT), Hargreaves-Samani (HS), and Mahringer (MG) methods, were adopted to estimate ET, which were then compared with ET measured using Eddy Covariance (EC) for five alpine meadow sites during the growing seasons from 2010 to 2014. And each site was measured for one growing season during this period. The results demonstrate that the PT method outperformed at all sites with a coefficient of determination (R2) ranging from 0.76 to 0.94 and root mean square error (RMSE) ranging from 0.41 to 0.62 mm d-1. The PM method showed better performance than HS and MG methods, and the HS method produced relatively acceptable results with higher R2 (0.46) and lower RMSE (0.89 mm d-1) compared to MG method with R2 of 0.16 and RMSE of 1.62 mm d-1, while MG underestimated ET at all alpine meadow sites. Therefore, the PT method, being the simpler approach and less data dependent, is recommended to estimate ET for alpine meadow areas in the Tibetan Plateau. The PM method produced reliable results when available data were sufficient, and the HS method proved to be a complementary method when variables were insufficient. On the contrary, the MG method always underestimated ET and is, thus, not suitable for alpine meadows. These results provide a basis for estimating ET on the Tibetan Plateau for annual data collection, analysis, and future studies. PMID:29236754

Laboratory grown subaerial biofilms on granite: application to the study of bioreceptivity.

PubMed

Vázquez-Nion, Daniel; Silva, Benita; Troiano, Federica; Prieto, Beatriz

2017-01-01

Simulated environmental colonisation of granite was induced under laboratory conditions in order to develop an experimental protocol for studying bioreceptivity. The experimental set-up proved suitable for producing subaerial biofilms by inoculating granite blocks with planktonic multi-species phototrophic cultures derived from natural biofilms. The ability of four different cultures to form biofilms was monitored over a three-month growth period via colour measurements, quantification of photosynthetic pigments and EPS, and CLSM observations. One of the cultures under study, which comprised several taxa including Bryophyta, Charophyta, Chlorophyta and Cyanobacteria, was particularly suitable as an inoculum, mainly because of its microbial richness, its rapid adaptability to the substratum and its high colonisation capacity. The use of this culture as an inoculum in the proposed experimental set-up to produce subaerial biofilms under laboratory conditions will contribute to standardising the protocols involved, thus enabling more objective assessment of the bioreceptivity of granite in further experiments.

Use of ERTS imagery in air pollution and marine biology studies, tasks 1 through 3

NASA Technical Reports Server (NTRS)

Copeland, G. E.; Ludwick, J. C.; Marshall, H. G. (Principal Investigator); Bandy, A. R.; Fleischer, P.; Hanna, W. J.; Gosink, T. A.; Bowker, D. W.

1972-01-01

There are no author-identified significant results in this report. The general suitability of ERTS imagery in detecting ground originated air pollution has proved to be excellent. The quality and resolution exceeded expectations and has permitted in some instances location of point sources to within a thousand feet. Suitable techniques have not yet been developed for determining or measuring area and line sources of air pollution. A major problem has been cloud cover that has persisted over the area of primary interest, the Chesapeake Bay. Work has been completed on mounting the shipboard transmissometer which will be used for investigations to relate the chlorophyll and suspended sediment content in the waters of the Lower Chesapeake Bay to ERTS-1 imagery. Water sampling, plankton analysis, and preparations for sea collection of water truth along the eastern continental shelf of the U.S. have been completed for use in comparisons with ERTS-1 data.

The Galaxen model--a concept for rehabilitation and prevention in the construction industry.

PubMed

Stenlund, Berndt

2005-01-01

The Galaxen model was developed during the late 1980s to provide rehabilitation and prevention activities in the construction industry. It handles around 1200 workers with long-term sick leave or partial disabilities annually, some 10% of whom annually leave Galaxen for an ordinary job without a wage subsidy. The model includes a decision by a rehabilitation board of representatives from the employers, the trade union, and the regional employment office, a rehabilitation plan, allotment of a case manager, wage subsidies from the State to the company, a search for a suitable job in relation to the partial disability. It also includes a preventive program with emphasis on practical ergonomics. The Galaxen model has proved to be a suitable means of rehabilitating construction workers and returning them to the workforce. The model was developed within the Swedish social security system but could well be adjusted to other contexts.

Phase Change Energy Storage Material Suitable for Solar Heating System

NASA Astrophysics Data System (ADS)

Li, Xiaohui; Li, Haihua; Zhang, Lihui; Liu, Zhenfa

2018-01-01

Differential scanning calorimetry (DSC) was used to investigate the thermal properties of palmitic acid, myristic acid, laurel acid and the binary composite of palmitic/laurel acid and palmitic/myristic acid. The results showed that the phase transition temperatures of the three monomers were between 46.9-65.9°C, and the latent heats were above 190 J/g, which could be used as solar energy storage material. When the mass ratio of Palmitic acid and myristic was 1:1, the eutectic mixture could be formed. The latent heat of the eutectic mixture was 186.6 J/g, the melting temperature and the solidification temperature was 50.6°C and 43.8°C respectively. The latent heat of phase change and the melting temperature had not obvious variations after 400 thermal cycles, which proved that the binary composite had good thermal stability and was suitable for solar floor radiant heating system.

On Everhart Method

NASA Astrophysics Data System (ADS)

Pârv, Bazil

This paper deals with the Everhart numerical integration method, a well-known method in astronomical research. This method, a single-step one, is widely used for numerical integration of motion equation of celestial bodies. For an integration step, this method uses unequally-spaced substeps, defined by the roots of the so-called generating polynomial of Everhart's method. For this polynomial, this paper proposes and proves new recurrence formulae. The Maple computer algebra system was used to find and prove these formulae. Again, Maple seems to be well suited and easy to use in mathematical research.

A Wide Linearity Range Method for the Determination of Lenalidomide in Plasma by High-Performance Liquid Chromatography: Application to Pharmacokinetic Studies.

PubMed

Guglieri-López, Beatriz; Pérez-Pitarch, Alejandro; Martinez-Gómez, Maria Amparo; Porta-Oltra, Begoña; Climente-Martí, Mónica; Merino-Sanjuán, Matilde

2016-12-01

A wide linearity range analytical method for the determination of lenalidomide in patients with multiple myeloma for pharmacokinetic studies is required. Plasma samples were ultrasonicated for protein precipitation. A solid-phase extraction was performed. The eluted samples were evaporated to dryness under vacuum, and the solid obtained was diluted and injected into the high-performance liquid chromatography (HPLC) system. Separation of lenalidomide was performed on an Xterra RP C18 (250 mm length × 4.6 mm i.d., 5 µm) using a mobile phase consisting of phosphate buffer/acetonitrile (85:15, v/v, pH 3.2) at a flow rate of 0.5 mL · min -1 The samples were monitored at a wavelength of 311 nm. A linear relationship with good correlation coefficient (r = 0.997, n = 9) was found between the peak area and lenalidomide concentrations in the range of 100 to 950 ng · mL -1 The limits of detection and quantitation were 28 and 100 ng · mL -1 , respectively. The intra- and interassay precisions were satisfactory, and the accuracy of the method was proved. In conclusion, the proposed method is suitable for the accurate quantification of lenalidomide in human plasma with a wide linear range, from 100 to 950 ng · mL -1 This is a valuable method for pharmacokinetic studies of lenalidomide in human subjects. © 2016 Society for Laboratory Automation and Screening.

Development and Validation of a UHPLC UV Method for the In-Process Control of Bosentan Monohydrate Synthesis.

PubMed

Jatczak, Marta; Sidoryk, Katarzyna; Kossykowska, Magdalena; Łuniewski, Wojciech; Zagrodzka, Joanna; Lipiec-Abramska, Elżbieta

2016-01-01

Bosentan monohydrate (4- tert -butyl- N -[6-(2-hydroxyethoxy)-5-(2-methoxyphenoxy)-2-(pyrimidin-2-yl) pyrimidin-4-yl]benzene-1-sulfonamide monohydrate) is a dual endothelin receptor antagonist (ERA) applied in the treatment of pulmonary arterial hypertension. To achieve effective process control of the bosentan monohydrate synthesis, it was necessary to develop a selective and not highly time-consuming method for ultra-high performance liquid chromatography (UHPLC). The method is characterized by adequate sensitivity, reproducibility and selectivity for the determination of bosentan monohydrate and related compounds from all synthetic stages. The UHPLC separation was carried out by reversed phase chromatography on the Acquity BEH C18 column (100 mm × 2.1 mm, 1.7 µm) with a mobile phase composed of solvent A (0.1 %, v/v, acetic acid in water) and solvent B (methanol), in the gradient mode at the flow rate of 0.4 mL min -1 . Limits of detection and quantification for the compounds were ≤0.1 µg mL -1 and 0.3 µg mL -1 , respectively. The linearity for all related compounds was investigated as in the range for the active pharmaceutical ingredient (API) and as in the range for the in-process control. The developed method was validated according to the current guidelines, proving the suitability of the method for its intended purpose.

Efficient Nash Equilibrium Resource Allocation Based on Game Theory Mechanism in Cloud Computing by Using Auction

PubMed Central

Nezarat, Amin; Dastghaibifard, GH

2015-01-01

One of the most complex issues in the cloud computing environment is the problem of resource allocation so that, on one hand, the cloud provider expects the most profitability and, on the other hand, users also expect to have the best resources at their disposal considering the budget constraints and time. In most previous work conducted, heuristic and evolutionary approaches have been used to solve this problem. Nevertheless, since the nature of this environment is based on economic methods, using such methods can decrease response time and reducing the complexity of the problem. In this paper, an auction-based method is proposed which determines the auction winner by applying game theory mechanism and holding a repetitive game with incomplete information in a non-cooperative environment. In this method, users calculate suitable price bid with their objective function during several round and repetitions and send it to the auctioneer; and the auctioneer chooses the winning player based the suggested utility function. In the proposed method, the end point of the game is the Nash equilibrium point where players are no longer inclined to alter their bid for that resource and the final bid also satisfies the auctioneer’s utility function. To prove the response space convexity, the Lagrange method is used and the proposed model is simulated in the cloudsim and the results are compared with previous work. At the end, it is concluded that this method converges to a response in a shorter time, provides the lowest service level agreement violations and the most utility to the provider. PMID:26431035

Efficient Nash Equilibrium Resource Allocation Based on Game Theory Mechanism in Cloud Computing by Using Auction.

PubMed

Nezarat, Amin; Dastghaibifard, G H

2015-01-01

One of the most complex issues in the cloud computing environment is the problem of resource allocation so that, on one hand, the cloud provider expects the most profitability and, on the other hand, users also expect to have the best resources at their disposal considering the budget constraints and time. In most previous work conducted, heuristic and evolutionary approaches have been used to solve this problem. Nevertheless, since the nature of this environment is based on economic methods, using such methods can decrease response time and reducing the complexity of the problem. In this paper, an auction-based method is proposed which determines the auction winner by applying game theory mechanism and holding a repetitive game with incomplete information in a non-cooperative environment. In this method, users calculate suitable price bid with their objective function during several round and repetitions and send it to the auctioneer; and the auctioneer chooses the winning player based the suggested utility function. In the proposed method, the end point of the game is the Nash equilibrium point where players are no longer inclined to alter their bid for that resource and the final bid also satisfies the auctioneer's utility function. To prove the response space convexity, the Lagrange method is used and the proposed model is simulated in the cloudsim and the results are compared with previous work. At the end, it is concluded that this method converges to a response in a shorter time, provides the lowest service level agreement violations and the most utility to the provider.

Influential aspects of glacial resource for establishing Kuhl system (gravity flow irrigation) in the Hindu Kush, Karakoram and Himalaya ranges.

PubMed

Ashraf, Arshad; Iqbal, Ayesha

2018-04-27

The meltwater components play an important role in the hydrological regime of the Hindu Kush, Karakorum and Himalaya (HKH) region, in terms of high demand of water for food and fiber from snow and glacial resource. The communities of Himalayan mountains are facing challenges of food security owing to lack of the resource information for meeting their water requirements. In this study, suitability index approach was adopted to assess glacier resource potential for establishing kuhl irrigation system in HKH ranges of Pakistan. The basis of indexing is glacier accessibility and water yield potential of the glacial resource for irrigation estimated in terms of number and ice reserve of the glaciers. The suitability index was found good for about 1.4% glaciers constituting about 80% of the total ice reserves of the HKH region. Medium suitability constitutes about 36.1% glaciers with 12.6% of the total ice reserves, while low suitability was assessed for about 60% glaciers containing 1.5% ice reserves only. Maximum unit glacial reserve was estimated for Shigar basin, i.e., 1.44 km 3 , and among HKH ranges, 0.46 km 3 for the Karakoram range. A regular monitoring of the glacial resource would prove helpful in assessing vulnerability of this resource to climate change in the high Himalayan region in future. Copyright © 2018. Published by Elsevier B.V.

Efficient algorithms for analyzing the singularly perturbed boundary value problems of fractional order

NASA Astrophysics Data System (ADS)

Sayevand, K.; Pichaghchi, K.

2018-04-01

In this paper, we were concerned with the description of the singularly perturbed boundary value problems in the scope of fractional calculus. We should mention that, one of the main methods used to solve these problems in classical calculus is the so-called matched asymptotic expansion method. However we shall note that, this was not achievable via the existing classical definitions of fractional derivative, because they do not obey the chain rule which one of the key elements of the matched asymptotic expansion method. In order to accommodate this method to fractional derivative, we employ a relatively new derivative so-called the local fractional derivative. Using the properties of local fractional derivative, we extend the matched asymptotic expansion method to the scope of fractional calculus and introduce a reliable new algorithm to develop approximate solutions of the singularly perturbed boundary value problems of fractional order. In the new method, the original problem is partitioned into inner and outer solution equations. The reduced equation is solved with suitable boundary conditions which provide the terminal boundary conditions for the boundary layer correction. The inner solution problem is next solved as a solvable boundary value problem. The width of the boundary layer is approximated using appropriate resemblance function. Some theoretical results are established and proved. Some illustrating examples are solved and the results are compared with those of matched asymptotic expansion method and homotopy analysis method to demonstrate the accuracy and efficiency of the method. It can be observed that, the proposed method approximates the exact solution very well not only in the boundary layer, but also away from the layer.

Comparative study of Wenner and Schlumberger electrical resistivity method for groundwater investigation: a case study from Dhule district (M.S.), India

NASA Astrophysics Data System (ADS)

Vasantrao, Baride Mukund; Bhaskarrao, Patil Jitendra; Mukund, Baride Aarti; Baburao, Golekar Rushikesh; Narayan, Patil Sanjaykumar

2017-12-01

The area chosen for the present study is Dhule district, which belongs to the drought prone area of Maharashtra State, India. Dhule district suffers from water problem, and therefore, there is no extra water available to supply for the agricultural and industrial growth. To understand the lithological characters in terms of its hydro-geological conditions, it is necessary to understand the geology of the area. It is now established fact that the geophysical method gives a better information of subsurface geology. Geophysical electrical surveys with four electrodes configuration, i.e., Wenner and Schlumberger method, were carried out at the same selected sites to observe the similarity and compared both the applications in terms of its use and handling in the field. A total 54 VES soundings were carried out spread over the Dhule district and representing different lithological units. The VES curves are drawn using inverse slope method for Wenner configuration, IPI2 win Software, and curve matching techniques were used for Schlumberger configuration. Regionwise lithologs are prepared based on the obtained resistivity and thickness for Wenner method. Regionwise curves were prepared based on resistivity layers for Schlumberger method. Comparing the two methods, it is observed that Wenner and Schlumberger methods have merits or demerits. Considering merits and demerits from the field point of view, it is suggested that Wenner inverse slope method is more handy for calculation and interpretation, but requires lateral length which is a constrain. Similarly, Schlumberger method is easy in application but unwieldy for their interpretation. The work amply proves the applicability of geophysical techniques in the water resource evaluation procedure. This technique is found to be suitable for the areas with similar geological setup elsewhere.

Evaluation of field methods for vertical high resolution aquifer characterization

NASA Astrophysics Data System (ADS)

Vienken, T.; Tinter, M.; Rogiers, B.; Leven, C.; Dietrich, P.

2012-12-01

The delineation and characterization of subsurface (hydro)-stratigraphic structures is one of the challenging tasks of hydrogeological site investigations. The knowledge about the spatial distribution of soil specific properties and hydraulic conductivity (K) is the prerequisite for understanding flow and fluid transport processes. This is especially true for heterogeneous unconsolidated sedimentary deposits with a complex sedimentary architecture. One commonly used approach to investigate and characterize sediment heterogeneity is soil sampling and lab analyses, e.g. grain size distribution. Tests conducted on 108 samples show that calculation of K based on grain size distribution is not suitable for high resolution aquifer characterization of highly heterogeneous sediments due to sampling effects and large differences of calculated K values between applied formulas (Vienken & Dietrich 2011). Therefore, extensive tests were conducted at two test sites under different geological conditions to evaluate the performance of innovative Direct Push (DP) based approaches for the vertical high resolution determination of K. Different DP based sensor probes for the in-situ subsurface characterization based on electrical, hydraulic, and textural soil properties were used to obtain high resolution vertical profiles. The applied DP based tools proved to be a suitable and efficient alternative to traditional approaches. Despite resolution differences, all of the applied methods captured the main aquifer structure. Correlation of the DP based K estimates and proxies with DP based slug tests show that it is possible to describe the aquifer hydraulic structure on less than a meter scale by combining DP slug test data and continuous DP measurements. Even though correlations are site specific and appropriate DP tools must be chosen, DP is reliable and efficient alternative for characterizing even strongly heterogeneous sites with complex structured sedimentary aquifers (Vienken et al. 2012). References: Vienken, T., Leven, C., and Dietrich, P. 2012. Use of CPT and other direct push methods for (hydro-) stratigraphic aquifer characterization — a field study. Canadian Geotechnical Journal, 49(2): 197-206. Vienken, T., and Dietrich, P. 2011. Field evaluation of methods for determining hydraulic conductivity from grain size data. Journal of Hydrology, 400(1-2): 58-71.

Proposal of a framework for evaluating military surveillance systems for early detection of outbreaks on duty areas

PubMed Central

Meynard, Jean-Baptiste; Chaudet, Herve; Green, Andrew D; Jefferson, Henry L; Texier, Gaetan; Webber, Daniel; Dupuy, Bruce; Boutin, Jean-Paul

2008-01-01

Background In recent years a wide variety of epidemiological surveillance systems have been developed to provide early identification of outbreaks of infectious disease. Each system has had its own strengths and weaknesses. In 2002 a Working Group of the Centers for Disease Control and Prevention (CDC) produced a framework for evaluation, which proved suitable for many public health surveillance systems. However this did not easily adapt to the military setting, where by necessity a variety of different parameters are assessed, different constraints placed on the systems, and different objectives required. This paper describes a proposed framework for evaluation of military syndromic surveillance systems designed to detect outbreaks of disease on operational deployments. Methods The new framework described in this paper was developed from the cumulative experience of British and French military syndromic surveillance systems. The methods included a general assessment framework (CDC), followed by more specific methods of conducting evaluation. These included Knowledge/Attitude/Practice surveys (KAP surveys), technical audits, ergonomic studies, simulations and multi-national exercises. A variety of military constraints required integration into the evaluation. Examples of these include the variability of geographical conditions in the field, deployment to areas without prior knowledge of naturally-occurring disease patterns, the differences in field sanitation between locations and over the length of deployment, the mobility of military forces, turnover of personnel, continuity of surveillance across different locations, integration with surveillance systems from other nations working alongside each other, compatibility with non-medical information systems, and security. Results A framework for evaluation has been developed that can be used for military surveillance systems in a staged manner consisting of initial, intermediate and final evaluations. For each stage of the process parameters for assessment have been defined and methods identified. Conclusion The combined experiences of French and British syndromic surveillance systems developed for use in deployed military forces has allowed the development of a specific evaluation framework. The tool is suitable for use by all nations who wish to evaluate syndromic surveillance in their own military forces. It could also be useful for civilian mobile systems or for national security surveillance systems. PMID:18447944

TECHNICAL BRIEF: Isolation of total DNA from postmortem human eye tissues and quality comparison between iris and retina

PubMed Central

Wang, Jay Ching Chieh; Wang, Aikun; Gao, Jiangyuan; Cao, Sijia; Samad, Idris; Zhang, Dean; Ritland, Carol; Cui, Jing Z.

2012-01-01

Background Recent genomic technologies have propelled our understanding of the mechanisms underlying complex eye diseases such as age-related macular degeneration (AMD). Genotyping postmortem eye tissues for known single nucleotide polymorphisms (SNPs) associated with AMD may prove valuable, especially when combined with information obtained through other methods such as immunohistochemistry, western blot, enzyme-linked immunosorbent assay (ELISA), and proteomics. Initially intending to genotype postmortem eye tissues for AMD-related SNPs, our group became interested in isolating and comparing the quality of DNA from the iris and retina of postmortem donor eyes. Since there is no previously published protocol in the literature on this topic, we present a protocol suitable for isolating high-quality DNA from postmortem eye tissues for genomic studies. Methods DNA from 33 retinal samples and 35 iris samples was extracted using the phenol-chloroform-isoamyl method from postmortem donor eye tissues. The quantity of DNA was measured with a spectrophotometer while the quality was checked using gel electrophoresis. The DNA samples were then amplified with PCR for the complement factor H (CFH) gene. The purified amplified products were then genotyped for the SNPs in the CFH gene. Results Regarding concentration, the retina yielded 936 ng/μl of DNA, while the iris yielded 78 ng/μl of DNA. Retinal DNA was also purer than iris DNA (260/280=1.78 vs. 1.46, respectively), and produced superior PCR results. Retinal tissue yielded significantly more DNA than the iris tissue per mg of sample (21.7 ng/μl/mg vs. 7.42 ng/μl/mg). Retinal DNA can be readily amplified with PCR, while iris DNA can also be amplified by adding bovine serum albumin. Overall, retinal tissues yielded DNA of superior quality, quantity, and suitability for genotyping and genomic studies. Conclusions The protocol presented here provides a clear and reliable method for isolating total DNA from postmortem eye tissues. Retinal tissue provides DNA of excellent quantity and quality for genotyping and downstream genomic studies. However, DNA isolated from iris tissues, and treated with bovine serum albumin, may also be a valuable source of DNA for genotyping and genomic studies. PMID:23288996

Iterative methods used in overlap astrometric reduction techniques do not always converge

NASA Astrophysics Data System (ADS)

Rapaport, M.; Ducourant, C.; Colin, J.; Le Campion, J. F.

1993-04-01

In this paper we prove that the classical Gauss-Seidel type iterative methods used for the solution of the reduced normal equations occurring in overlapping reduction methods of astrometry do not always converge. We exhibit examples of divergence. We then analyze an alternative algorithm proposed by Wang (1985). We prove the consistency of this algorithm and verify that it can be convergent while the Gauss-Seidel method is divergent. We conjecture the convergence of Wang method for the solution of astrometric problems using overlap techniques.

Structural stability and chaotic solutions of perturbed Benjamin-Ono equations

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

Birnir, B.; Morrison, P.J.

1986-11-01

A method for proving chaos in partial differential equations is discussed and applied to the Benjamin-Ono equation subject to perturbations. The perturbations are of two types: one that corresponds to viscous dissipation, the so-called Burger's term, and one that involves the Hilbert transform and has been used to model Landau damping. The method proves chaos in the PDE by proving temporal chaos in its pole solutions. The spatial structure of the pole solutions remains intact, but their positions are chaotic in time. Melnikov's method is invoked to show this temporal chaos. It is discovered that the pole behavior is verymore » sensitive to the Burger's perturbation, but is quite insensitive to the perturbation involving the Hilbert transform.« less

Comparasion of Password Generator between Coupled Linear Congruential Generator (CLCG) and Linear Congruential Generator (LCG)

NASA Astrophysics Data System (ADS)

Imamah; Djunaidy, A.; Rachmad, A.; Damayanti, F.

2018-01-01

Password is needed to access the computing services. Text password is a combination between characters, numbers and symbols. One of issues is users will often choose guessable passwords, e.g. date of birth, name of pet, or anniversary date. To address this issue, we proposed password generator using Coupled Congruential method (CLCG). CLCG is a method to solve the weakness of Linear Congruential generator (LCG). In this research, we want to prove that CLCG is really good to generate random password compared to LCG method. The result of this research proves that the highest password strength is obtained by CLCG with score 77.4%. Besides of those things, we had proved that term of LCG is also applicable to CLCG.

Investigation of nuclear stopping observable in heavy ion collisions

NASA Astrophysics Data System (ADS)

Deepshikha; Kumar, Suneel

2018-07-01

Detailed analysis has been made on nuclear stopping using various observable. Transport model, isospin dependent quantum molecular dynamics model (IQMD) has been used to study stopping over the whole mass range at incident energies between 10 MeV/nucleon and 1000 MeV/nucleon. Our study proves that ratio of width of transverse to longitudinal rapidity distribution i.e., < varxz > is the most suitable parameter to study nuclear stopping. Also, it has been observed that light mass fragments (LMF's) emitted from participant region can be used as barometer to study nuclear stopping.

Water-Based Electroplating Maskant Is Safer

NASA Technical Reports Server (NTRS)

Pickett, Garry M.

1996-01-01

Report proposes use of commercial water-based electroplating maskant Tolber 0-18 as nontoxic alternative to commercial organic-solvent-based electroplating maskant Turco 531-A. Tolber 0-18 found to be equal or superior in key properties, including suitability for application by brushing, effectiveness of sealing, and durability. In addition, exerts no adverse effect on environment or on health of workers, and enables users to comply with local and federal antipollution laws. Use of maskant proves beneficial in most, if not all, electroplating applications involving brush application of maskants to areas not to be electroplated.

An improved synthesis of pyran-3,5-dione: application to the synthesis of ABT-598, a potassium channel opener, via Hantzsch reaction.

PubMed

Li, Wenke; Wayne, Gregory S; Lallaman, John E; Chang, Sou-Jen; Wittenberger, Steven J

2006-02-17

Ketoester 1 is cyclized to give pyran-3,5-dione 2 in 78% yield using a parallel addition of ketoester 1 and base NaO(t)Bu in refluxing THF. Compared to the previously reported procedures, these optimized conditions have significantly increased the yield of this transformation and the quality of pyran 2 and prove to be suitable for large-scale preparation. An application of 2 to the synthesis of ABT-598, a potassium channel opener, is demonstrated.

Measure-valued solutions to nonlocal transport equations on networks

NASA Astrophysics Data System (ADS)

Camilli, Fabio; De Maio, Raul; Tosin, Andrea

2018-06-01

Aiming to describe traffic flow on road networks with long-range driver interactions, we study a nonlinear transport equation defined on an oriented network where the velocity field depends not only on the state variable but also on the distribution of the population. We prove existence, uniqueness and continuous dependence results of the solution intended in a suitable measure-theoretic sense. We also provide a representation formula in terms of the push-forward of the initial and boundary data along the network and discuss an explicit example of nonlocal velocity field fitting our framework.

Sequential Multicomponent Strategy for the Diastereoselective Synthesis of Densely Functionalized Spirooxindole-Fused Thiazolidines.

PubMed

Rainoldi, Giulia; Begnini, Fabio; de Munnik, Mariska; Lo Presti, Leonardo; Vande Velde, Christophe M L; Orru, Romano; Lesma, Giordano; Ruijter, Eelco; Silvani, Alessandra

2018-02-12

We developed two Ugi-type three-component reactions of spirooxindole-fused 3-thiazolines, isocyanides, and either carboxylic acids or trimethylsilyl azide, to give highly functionalized spirooxindole-fused thiazolidines. Two diverse libraries were generated using practical and robust procedures affording the products in typically good yields. The obtained thiazolidines proved to be suitable substrates for further transformations. Notably, both the Ugi-Joullié and the azido-Ugi reactions resulted highly diastereoselective, affording predominantly the trans-configured products, as confirmed by X-ray crystallographic analysis.

Constructive tensorial group field theory II: the {U(1)-T^4_4} model

NASA Astrophysics Data System (ADS)

Lahoche, Vincent

2018-05-01

In this paper, we continue our program of non-pertubative constructions of tensorial group field theories (TGFT). We prove analyticity and Borel summability in a suitable domain of the coupling constant of the simplest super-renormalizable TGFT which contains some ultraviolet divergencies, namely the color-symmetric quartic melonic rank-four model with Abelian gauge invariance, nicknamed . We use a multiscale loop vertex expansion. It is an extension of the loop vertex expansion (the basic constructive technique for non-local theories) which is required for theories that involve non-trivial renormalization.

Metal vinylidenes and allenylidenes in catalysis: applications in anti-Markovnikov additions to terminal alkynes and alkene metathesis.

PubMed

Bruneau, Christian; Dixneuf, Pierre H

2006-03-27

The involvement of a catalytic metal vinylidene species was proposed for the first time in 1986 to explain the regioselective formation of vinyl carbamates directly from terminal alkynes, carbon dioxide, and amines. Since this initial report, various metal vinylidenes and allenylidenes, which are key activation intermediates, have proved extremely useful for many alkyne transformations. They have contributed to the rational design of new catalytic reactions. This 20th anniversary is a suitable occasion to present the advancement of organometallic vinylidenes and allenylidenes in catalysis.

Aircraft Energy Efficiency (ACEE) status report

NASA Technical Reports Server (NTRS)

Nored, D. L.; Dugan, J. F., Jr.; Saunders, N. T.; Ziemianski, J. A.

1979-01-01

Fuel efficiency in aeronautics, for fuel conservation in general as well as for its effect on commercial aircraft operating economics is considered. Projects of the Aircraft Energy Efficiency Program related to propulsion are emphasized. These include: (1) engine component improvement, directed at performance improvement and engine diagnostics for prolonged service life; (2) energy efficient engine, directed at proving the technology base for the next generation of turbofan engines; and (3) advanced turboprop, directed at advancing the technology of turboprop powered aircraft to a point suitable for commercial airline service. Progress in these technology areas is reported.

Motion Among Random Obstacles on a Hyperbolic Space

NASA Astrophysics Data System (ADS)

Orsingher, Enzo; Ricciuti, Costantino; Sisti, Francesco

2016-02-01

We consider the motion of a particle along the geodesic lines of the Poincaré half-plane. The particle is specularly reflected when it hits randomly-distributed obstacles that are assumed to be motionless. This is the hyperbolic version of the well-known Lorentz Process studied in the Euclidean context. We analyse the limit in which the density of the obstacles increases to infinity and the size of each obstacle vanishes: under a suitable scaling, we prove that our process converges to a Markovian process, namely a random flight on the hyperbolic manifold.

Evaluation of IKTS Transparent Polycrystalline Magnesium Aluminate Spinel (MgAl2O4) for Armor and Infrared Dome/Window Applications

DTIC Science & Technology

2013-03-01

interacted with (15). 4.3.3 Experimental Procedure Two MgAl2O4 spinel samples with nominal 0.6- and 1.6-μm mean grain sizes were tested using advanced...unable to make specific quantitative predictions at this time. Due to the nature of the experimental process, this technique is suitable only for...Information From Spherical Indentation; ARL-TR-4229; U.S. Army Research Laboratory: Aberdeen Proving Ground, MD, 2007. 24. ASTM E112. Standard Test

Successful treatment of pure aortic insufficiency with transapical implantation of the JenaValve.

PubMed

Bleiziffer, Sabine; Mazzitelli, Domenico; Nöbauer, Christian; Ried, Thomas; Lange, Rüdiger

2013-08-01

Transcatheter aortic valve implantation was predominantly developed for patients with severe calcified aortic stenosis, as most devices are designed to anchor within the native valve calcium. We report on a patient with pure insufficiency of a non-calcified aortic valve, in whom an anatomically oriented catheter valve was implanted successfully. The design of the prosthesis with position feelers engaging the native aortic valve leaflets proved to be suitable for the treatment of pure aortic insufficiency. Georg Thieme Verlag KG Stuttgart · New York.

Determining the most suitable areas for artificial groundwater recharge via an integrated PROMETHEE II-AHP method in GIS environment (case study: Garabaygan Basin, Iran).

PubMed

Nasiri, Hossein; Boloorani, Ali Darvishi; Sabokbar, Hassan Ali Faraji; Jafari, Hamid Reza; Hamzeh, Mohamad; Rafii, Yusef

2013-01-01

Flood spreading is a suitable strategy for controlling and benefiting from floods. Selecting suitable areas for flood spreading and directing the floodwater into permeable formations are amongst the most effective strategies in flood spreading projects. Having combined geographic information systems (GIS) and multi-criteria decision analysis approaches, the present study sought to locate the most suitable areas for flood spreading operation in the Garabaygan Basin of Iran. To this end, the data layers relating to the eight effective factors were prepared in GIS environment. This stage was followed by elimination of the exclusionary areas for flood spreading while determining the potentially suitable ones. Having closely examined the potentially suitable areas using the Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE) II and analytic hierarchy process (AHP) methods, the land suitability map for flood spreading was produced. The PROMETHEE II and AHP were used for ranking all the alternatives and weighting the criteria involved, respectively. The results of the study showed that most suitable areas for the artificial groundwater recharge are located in Quaternary Q(g) and Q(gsc) geologic units and in geomorphological units of pediment and Alluvial fans with slopes not exceeding 3%. Furthermore, significant correspondence between the produced map and the control areas, where the flood spreading projects were successfully performed, provided further evidence for the acceptable efficiency of the integrated PROMETHEE II-AHP method in locating suitable flood spreading areas.

A Novel and Intelligent Home Monitoring System for Care Support of Elders with Cognitive Impairment.

PubMed

Lazarou, Ioulietta; Karakostas, Anastasios; Stavropoulos, Thanos G; Tsompanidis, Theodoros; Meditskos, Georgios; Kompatsiaris, Ioannis; Tsolaki, Magda

2016-10-18

Assistive technology, in the form of a smart home environment, is employed to support people with dementia. To propose a system for continuous and objective remote monitoring of problematic daily living activity areas and design personalized interventions based on system feedback and clinical observations for improving cognitive function and health-related quality of life. The assistive technology of the proposed system, including wearable, sleep, object motion, presence, and utility usage sensors, was methodically deployed at four different home installations of people with cognitive impairment. Detection of sleep patterns, physical activity, and activities of daily living, based on the collected sensor data and analytics, was available at all times through comprehensive data visualization solutions. Combined with clinical observation, targeted psychosocial interventions were introduced to enhance the participants' quality of life and improve their cognitive functions and daily functionality. Meanwhile, participants and their caregivers were able to visualize a reduced set of information tailored to their needs. Overall, paired-sample t-test analysis of monitored qualities revealed improvement for all participants in neuropsychological assessment. Moreover, improvement was detected from the beginning to the end of the trial, in physical condition and in the domains of sleep. Detecting abnormalities via the system, for example in sleep quality, such as REM sleep, has proved to be critical to assess current status, drive interventions, and evaluate improvements in a reliable manner. It has been proved that the proposed system is suitable to support clinicians to reliably drive and evaluate clinical interventions toward quality of life improvement of people with cognitive impairment.

In-flight evaluation of an optical head motion tracker III

NASA Astrophysics Data System (ADS)

Tawada, Kazuho; Okamoto, Masakazu

2011-06-01

We have presented a new approach for Optical HMT (Head Motion Tracker) past years [1]-[4]. In existing Magnetic HMT, it is inevitable to conduct pre-mapping in order to obtain sufficient accuracy because of magnetic field's distortion caused by metallic material around HMT, such as cockpit and helmet. Optical HMT is commonly known as mapping-free tracker; however, it has some disadvantages on accuracy, stability against sunlight conditions, in terms of comparison with Magnetic HMT. We had succeeded to develop new HMT system, which can overcome particular disadvantages by integration with two area cameras, optical markers, image processing techniques and inertial sensors with simple algorithm in laboratory level environment (2008). We have also reported some experimental results conducted in flight test, which proved good accuracy even in the sunlight condition (2009). We have also reported some experimental results conducted in flight test, which proved good performance even in the night flight (2010). Shimadzu Corp. and JAXA (Japan Aerospace Exploration Agency) are conducting joint research named SAVERH (Situation Awareness and Visual Enhancer for Rescue Helicopter) [2]-[4] that aims at inventing method of presenting suitable information to the pilot to support search and rescue missions by helicopters. The HMT system has been evaluated through a series of flight evaluation in SAVERH and demonstrated the operation concept. In this report, we show result of the final evaluation of the HMD system through 12 flights including night flight. Also, those evaluation was done by integrated HMT system that was newly developed for the tests in this year.

Challenges of predicting the potential distribution of a slow-spreading invader: a habitat suitability map for an invasive riparian tree

USGS Publications Warehouse

Jarnevich, Catherine S.; Reynolds, Lindsay V.

2011-01-01

Understanding the potential spread of invasive species is essential for land managers to prevent their establishment and restore impacted habitat. Habitat suitability modeling provides a tool for researchers and managers to understand the potential extent of invasive species spread. Our goal was to use habitat suitability modeling to map potential habitat of the riparian plant invader, Russian olive (Elaeagnus angustifolia). Russian olive has invaded riparian habitat across North America and is continuing to expand its range. We compiled 11 disparate datasets for Russian olive presence locations (n = 1,051 points and 139 polygons) in the western US and used Maximum entropy (Maxent) modeling to develop two habitat suitability maps for Russian olive in the western United States: one with coarse-scale water data and one with fine-scale water data. Our models were able to accurately predict current suitable Russian olive habitat (Coarse model: training AUC = 0.938, test AUC = 0.907; Fine model: training AUC = 0.923, test AUC = 0.885). Distance to water was the most important predictor for Russian olive presence in our coarse-scale water model, but it was only the fifth most important variable in the fine-scale model, suggesting that when water bodies are considered on a fine scale, Russian olive does not necessarily rely on water. Our model predicted that Russian olive has suitable habitat further west from its current distribution, expanding into the west coast and central North America. Our methodology proves useful for identifying potential future areas of invasion. Model results may be influenced by locations of cultivated individuals and sampling bias. Further study is needed to examine the potential for Russian olive to invade beyond its current range. Habitat suitability modeling provides an essential tool for enhancing our understanding of invasive species spread.

Development and validation of a reversed-phase ion-pair high-performance liquid chromatographic method for the determination of risedronate in pharmaceutical preparations.

PubMed

Kyriakides, Demetra; Panderi, Irene

2007-02-12

A stability indicating, reversed-phase ion-pair high-performance liquid chromatographic method was developed and validated for the determination of risedronate in pharmaceutical dosage forms. The determination was performed on a BDS C(18) analytical column (250 mm x 4.6 mm i.d., 5 microm particle size); the mobile phase consisted of 0.005 M tetrabutylammonium hydroxide and 0.005 M pyrophosphate sodium (pH 7.0) mixed with acetonitrile in a ratio (78:22, v/v) and pumped at a flow rate 1.00 mL min(-1). The ultraviolet (UV) detector was operated at 262 nm. The retention times of magnesium ascorbyl phosphate, which was used as internal standard and risedronate were 4.94 and 5.95 min, respectively. The calibration graph was ranged from 2.50 to 20.00 microg mL(-1), while detection and quantitation limits were found to be 0.48 and 1.61 microg mL(-1), respectively. The intra- and inter-day percentage relative standard deviations, %R.S.D., were less than 5.9%, while the relative percentage error, %E(r), was less than 0.4%. The method was applied to the quality control of commercial tablets and content uniformity test and proved to be suitable for rapid and reliable quality control.

Randomized trial of the impact of a sun safety program on volunteers in outdoor venues.

PubMed

Cheng, Shaowei; Guan, Xin; Cao, Mei; Liu, Yalan; Zhai, Siwen

2011-04-01

A suitable sun safety educational program could help the public avoid sun exposure-induced skin damage. The objective of this study was to assess the impact of a sun safety program on volunteers in outdoor venues and explore the most effective sun safety education method in China. An intervention program was implemented to raise knowledge and behavior regarding sun exposure among volunteers in the outdoor competition venues in Beijing, China. Five intervention methods were used, including class education, free sunscreen samples, pamphlets, posters, and newsletters. The self-administered multiple-choice questionnaires were administered before and after the intervention. Two hundred and eighty-five subjects were enrolled, including 107 males (37.5%) and 178 females (62.5%). The intervention group showed improvement in sun safety knowledge and behavior. Other improvements were achieved in the field of sun safety awareness and intended behavior, with most of the items achieving no statistically significant differences. Subgroup A (multi-component interventions, including class education, free sunscreen samples, and written materials) achieved better results than subgroup B (written materials only) to improve sun safety knowledge and awareness. Sun safety education could improve volunteer 's sun safety knowledge and behavior in the outdoor venues in China. Multi-component interventions proved to be the most effective sun safety education method. © 2011 John Wiley & Sons A/S.

A novel dissolution method for evaluation of polysaccharide based colon specific delivery systems: A suitable alternative to animal sacrifice.

PubMed

Singh, Sachin Kumar; Yadav, Ankit Kumar; Prudhviraj, G; Gulati, Monica; Kaur, Puneet; Vaidya, Yogyata

2015-06-20

The most extensively used test for predicting in-vivo release kinetics of a drug from its orally administered dosage forms is dissolution testing. For polysaccharide based, colon targeted oral delivery systems, the entire path of the gut traversed by the dosage form needs to be simulated for assessing its in-vivo dissolution pattern. This includes the dissolution testing sequentially in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) and simulated colonic fluid (SCF). For SGF and SIF, simple and standardized composition is well-known. However, preparation of SCF requires addition of either the colonic contents of rodents or human faecal slurry. A method is proposed, wherein a mixture of five probiotics cultured in the presence of a prebiotic under anaerobic conditions is able to surrogate the colonic fluid. Release profiles of drug from colon targeted delivery systems in this medium were studied and compared to those generated in the conventionally used media containing rodent caecal contents and human faecal slurry. The results from the three studies were found to be quite similar. These findings suggest that the proposed medium may prove to be useful not only as a biorelevant and discriminatory method but may also help in achieving the 3Rs objective regarding the ethical use of animals. Copyright © 2015 Elsevier B.V. All rights reserved.

Liquid chromatography-tandem mass spectrometry for the quantification of moxifloxacin, ciprofloxacin, daptomycin, caspofungin, and isavuconazole in human plasma.

PubMed

Hösl, Julian; Gessner, André; El-Najjar, Nahed

2018-05-12

A simple and precise ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous analysis of five anti-infective agents used to treat severe infections [three antibiotics (daptomycin, moxifloxacin, ciprofloxacin) and two antifungals (isavuconazole, caspofungin)] in human plasma. Sample preparation was based on protein precipitation with ice cold methanol. All five agents were analyzed with the corresponding isotopically labeled internal standards. All analytes were detected in multiple reactions monitoring (MRM) using API 4000 triple-quadrupole mass spectrometer with electrospray (ESI) source operating in positive mode. The calibration curves were linear over the selected ranges (r > 0.99). The method is precise and accurate with a total run time of 5.5 min. Accuracy of all target analytes ranged between 95.9-116.6%, measured with an imprecision of less than 10.8%. The lower limit of quantification was 1.25 mg/L for caspofungin, 0.3125 mg/L for isavuconazole, 3.125 mg/L for daptomycin, 0.075 mg/L for ciprofloxacin, and 0.1875 mg/L for moxifloxacin. The successful application of the method in patient samples proved its suitability for the medical surveillance of antimicrobial therapy in intensive care units as well as to other pharmacokinetic studies. Copyright © 2018. Published by Elsevier B.V.

Quality characteristic of spray-drying egg white powders.

PubMed

Ma, Shuang; Zhao, Songning; Zhang, Yan; Yu, Yiding; Liu, Jingbo; Xu, Menglei

2013-10-01

Spray drying is a useful method for developing egg process and utilization. The objective of this study was to evaluate effects on spray drying condition of egg white. The optimized conditions were spraying flow 22 mL/min, feeding temperature 39.8 °C and inlet-air temperature 178.2 °C. Results of sulfydryl (SH) groups measurement indicated conformation structure have changed resulting in protein molecule occur S-S crosslinking phenomenon when heating. It led to free SH content decreased during spray drying process. There was almost no change of differential scanning calorimetry between fresh egg white and spray-drying egg white powder (EWP). For a given protein, the apparent SH reactivity is in turn influenced by the physico-chemical characteristics of the reactant. The phenomenon illustrated the thermal denaturation of these proteins was unrelated to their free SH contents. Color measurement was used to study browning level. EWP in optimized conditions revealed insignificant brown stain. Swelling capacity and scanning electron micrograph both proved well quality characteristic of spray-drying EWP. Results suggested spray drying under the optimized conditions present suitable and alternative method for egg processing industrial implementation. Egg food industrialization needs new drying method to extend shelf-life. The purpose of the study was to provide optimal process of healthy and nutritional instant spray-drying EWP and study quality characteristic of spray-drying EWP.

Numerical analysis of flow instability in the water wall of a supercritical CFB boiler with annular furnace

NASA Astrophysics Data System (ADS)

Xie, Beibei; Yang, Dong; Xie, Haiyan; Nie, Xin; Liu, Wanyu

2016-08-01

In order to expand the study on flow instability of supercritical circulating fluidized bed (CFB) boiler, a new numerical computational model considering the heat storage of the tube wall metal was presented in this paper. The lumped parameter method was proposed for wall temperature calculation and the single channel model was adopted for the analysis of flow instability. Based on the time-domain method, a new numerical computational program suitable for the analysis of flow instability in the water wall of supercritical CFB boiler with annular furnace was established. To verify the code, calculation results were respectively compared with data of commercial software. According to the comparisons, the new code was proved to be reasonable and accurate for practical engineering application in analysis of flow instability. Based on the new program, the flow instability of supercritical CFB boiler with annular furnace was simulated by time-domain method. When 1.2 times heat load disturbance was applied on the loop, results showed that the inlet flow rate, outlet flow rate and wall temperature fluctuated with time eventually remained at constant values, suggesting that the hydrodynamic flow was stable. The results also showed that in the case of considering the heat storage, the flow in the water wall is easier to return to stable state than without considering heat storage.

[In vitro transdermal delivery of the active fraction of xiangfusiwu decoction based on principal component analysis].

PubMed

Li, Zhen-Hao; Liu, Pei; Qian, Da-Wei; Li, Wei; Shang, Er-Xin; Duan, Jin-Ao

2013-06-01

The objective of the present study was to establish a method based on principal component analysis (PCA) for the study of transdermal delivery of multiple components in Chinese medicine, and to choose the best penetration enhancers for the active fraction of Xiangfusiwu decoction (BW) with this method. Improved Franz diffusion cells with isolated rat abdomen skins were carried out to experiment on the transdermal delivery of six active components, including ferulic acid, paeoniflorin, albiflorin, protopine, tetrahydropalmatine and tetrahydrocolumbamine. The concentrations of these components were determined by LC-MS/MS, then the total factor scores of the concentrations at different times were calculated using PCA and were employed instead of the concentrations to compute the cumulative amounts and steady fluxes, the latter of which were considered as the indexes for optimizing penetration enhancers. The results showed that compared to the control group, the steady fluxes of the other groups increased significantly and furthermore, 4% azone with 1% propylene glycol manifested the best effect. The six components could penetrate through skin well under the action of penetration enhancers. The method established in this study has been proved to be suitable for the study of transdermal delivery of multiple components, and it provided a scientific basis for preparation research of Xiangfusiwu decoction and moreover, it could be a reference for Chinese medicine research.

Innovative self-calibration method for accelerometer scale factor of the missile-borne RINS with fiber optic gyro.

PubMed

Zhang, Qian; Wang, Lei; Liu, Zengjun; Zhang, Yiming

2016-09-19

The calibration of an inertial measurement unit (IMU) is a key technique to improve the preciseness of the inertial navigation system (INS) for missile, especially for the calibration of accelerometer scale factor. Traditional calibration method is generally based on the high accuracy turntable, however, it leads to expensive costs and the calibration results are not suitable to the actual operating environment. In the wake of developments in multi-axis rotational INS (RINS) with optical inertial sensors, self-calibration is utilized as an effective way to calibrate IMU on missile and the calibration results are more accurate in practical application. However, the introduction of multi-axis RINS causes additional calibration errors, including non-orthogonality errors of mechanical processing and non-horizontal errors of operating environment, it means that the multi-axis gimbals could not be regarded as a high accuracy turntable. As for its application on missiles, in this paper, after analyzing the relationship between the calibration error of accelerometer scale factor and non-orthogonality and non-horizontal angles, an innovative calibration procedure using the signals of fiber optic gyro and photoelectric encoder is proposed. The laboratory and vehicle experiment results validate the theory and prove that the proposed method relaxes the orthogonality requirement of rotation axes and eliminates the strict application condition of the system.

Orthogonal Procrustes Analysis for Dictionary Learning in Sparse Linear Representation

PubMed Central

Grossi, Giuliano; Lin, Jianyi

2017-01-01

In the sparse representation model, the design of overcomplete dictionaries plays a key role for the effectiveness and applicability in different domains. Recent research has produced several dictionary learning approaches, being proven that dictionaries learnt by data examples significantly outperform structured ones, e.g. wavelet transforms. In this context, learning consists in adapting the dictionary atoms to a set of training signals in order to promote a sparse representation that minimizes the reconstruction error. Finding the best fitting dictionary remains a very difficult task, leaving the question still open. A well-established heuristic method for tackling this problem is an iterative alternating scheme, adopted for instance in the well-known K-SVD algorithm. Essentially, it consists in repeating two stages; the former promotes sparse coding of the training set and the latter adapts the dictionary to reduce the error. In this paper we present R-SVD, a new method that, while maintaining the alternating scheme, adopts the Orthogonal Procrustes analysis to update the dictionary atoms suitably arranged into groups. Comparative experiments on synthetic data prove the effectiveness of R-SVD with respect to well known dictionary learning algorithms such as K-SVD, ILS-DLA and the online method OSDL. Moreover, experiments on natural data such as ECG compression, EEG sparse representation, and image modeling confirm R-SVD’s robustness and wide applicability. PMID:28103283

Identification procedure for epistemic uncertainties using inverse fuzzy arithmetic

NASA Astrophysics Data System (ADS)

Haag, T.; Herrmann, J.; Hanss, M.

2010-10-01

For the mathematical representation of systems with epistemic uncertainties, arising, for example, from simplifications in the modeling procedure, models with fuzzy-valued parameters prove to be a suitable and promising approach. In practice, however, the determination of these parameters turns out to be a non-trivial problem. The identification procedure to appropriately update these parameters on the basis of a reference output (measurement or output of an advanced model) requires the solution of an inverse problem. Against this background, an inverse method for the computation of the fuzzy-valued parameters of a model with epistemic uncertainties is presented. This method stands out due to the fact that it only uses feedforward simulations of the model, based on the transformation method of fuzzy arithmetic, along with the reference output. An inversion of the system equations is not necessary. The advancement of the method presented in this paper consists of the identification of multiple input parameters based on a single reference output or measurement. An optimization is used to solve the resulting underdetermined problems by minimizing the uncertainty of the identified parameters. Regions where the identification procedure is reliable are determined by the computation of a feasibility criterion which is also based on the output data of the transformation method only. For a frequency response function of a mechanical system, this criterion allows a restriction of the identification process to some special range of frequency where its solution can be guaranteed. Finally, the practicability of the method is demonstrated by covering the measured output of a fluid-filled piping system by the corresponding uncertain FE model in a conservative way.

[Climate suitability for tea growing in Zhejiang Province].

PubMed

Jin, Zhi-Feng; Ye, Jian-Gang; Yang, Zai-Qiang; Sun, Rui; Hu, Bo; Li, Ren-Zhong

2014-04-01

It is important to quantitatively assess the climate suitability of tea and its response to climate change. Based on meteorological indices of tea growth and daily meteorological data from 1971 to 2010 in Zhejiang Province, three climate suitability models for single climate factors, including temperature, precipitation and sunshine, were established at a 10-day scale by using the fuzzy mathematics method, and a comprehensive climate suitability model was established with the geometric average method. The results indicated that the climate suitability was high in the tea growth season in Zhejiang Province, and the three kinds of climate suitability were all higher than 0.6. As for the single factor climate suitability, temperature suitability was the highest and sunshine suitability was the lowest. There were obvious inter-annual variations of tea climate suitability, with a decline trend in the 1970s, less variation in the 1980s, and an obvious incline trend after the 1990s. The change tendency of climate suitability for spring tea was similar with that of annual climate suitability, lower in the 1980s, higher in the 1970s and after the 1990s. However, the variation amplitude of the climate suitability for spring tea was larger. The climate suitability for summer tea and autumn tea showed a decline trend from 1971 to 2010.

Phosphopeptide Enrichment by Covalent Chromatography after Derivatization of Protein Digests Immobilized on Reversed-Phase Supports

PubMed Central

Nika, Heinz; Nieves, Edward; Hawke, David H.; Angeletti, Ruth Hogue

2013-01-01

A rugged sample-preparation method for comprehensive affinity enrichment of phosphopeptides from protein digests has been developed. The method uses a series of chemical reactions to incorporate efficiently and specifically a thiol-functionalized affinity tag into the analyte by barium hydroxide catalyzed β-elimination with Michael addition using 2-aminoethanethiol as nucleophile and subsequent thiolation of the resulting amino group with sulfosuccinimidyl-2-(biotinamido) ethyl-1,3-dithiopropionate. Gentle oxidation of cysteine residues, followed by acetylation of α- and ε-amino groups before these reactions, ensured selectivity of reversible capture of the modified phosphopeptides by covalent chromatography on activated thiol sepharose. The use of C18 reversed-phase supports as a miniaturized reaction bed facilitated optimization of the individual modification steps for throughput and completeness of derivatization. Reagents were exchanged directly on the supports, eliminating sample transfer between the reaction steps and thus, allowing the immobilized analyte to be carried through the multistep reaction scheme with minimal sample loss. The use of this sample-preparation method for phosphopeptide enrichment was demonstrated with low-level amounts of in-gel-digested protein. As applied to tryptic digests of α-S1- and β-casein, the method enabled the enrichment and detection of the phosphorylated peptides contained in the mixture, including the tetraphosphorylated species of β-casein, which has escaped chemical procedures reported previously. The isolates proved highly suitable for mapping the sites of phosphorylation by collisionally induced dissociation. β-Elimination, with consecutive Michael addition, expanded the use of the solid-phase-based enrichment strategy to phosphothreonyl peptides and to phosphoseryl/phosphothreonyl peptides derived from proline-directed kinase substrates and to their O-sulfono- and O-linked β-N-acetylglucosamine (O-GlcNAc)-modified counterparts. Solid-phase enzymatic dephosphorylation proved to be a viable tool to condition O-GlcNAcylated peptide in mixtures with phosphopeptides for selective affinity purification. Acetylation, as an integral step of the sample-preparation method, precluded reduction in recovery of the thiolation substrate caused by intrapeptide lysine-dehydroalanine cross-link formation. The solid-phase analytical platform provides robustness and simplicity of operation using equipment readily available in most biological laboratories and is expected to accommodate additional chemistries to expand the scope of solid-phase serial derivatization for protein structural characterization. PMID:23997662

Hazard Assessment in a Big Data World

NASA Astrophysics Data System (ADS)

Kossobokov, Vladimir; Nekrasova, Anastasia

2017-04-01

Open data in a Big Data World provides unprecedented opportunities for enhancing scientific studies and better understanding of the Earth System. At the same time, it opens wide avenues for deceptive associations in inter- and transdisciplinary data misleading to erroneous predictions, which are unacceptable for implementation. Even the advanced tools of data analysis may lead to wrong assessments when inappropriately used to describe the phenomenon under consideration. A (self-) deceptive conclusion could be avoided by verification of candidate models in experiments on empirical data and in no other way. Seismology is not an exception. Moreover, seismic evidences accumulated to-date demonstrate clearly that most of the empirical relations commonly accepted in early history of instrumental seismology can be proved erroneous when subjected to objective hypothesis testing. In many cases of seismic hazard assessment (SHA), either probabilistic or deterministic, term-less or short-term, the claims of a high potential of a model forecasts are based on a flawed application of statistics and, therefore, are hardly suitable for communication to decision makers, which situation creates numerous deception points and resulted controversies. So far, most, if not all, the standard probabilistic methods to assess seismic hazard and associated risks are based on subjective, commonly unrealistic, and even erroneous assumptions about seismic recurrence and none of the proposed short-term precursory signals showed sufficient evidence to be used as a reliable precursor of catastrophic earthquakes. Accurate testing against real observations must be done in advance claiming seismically hazardous areas and/or times. The set of errors of the first and second kind in such a comparison permits evaluating the SHA method effectiveness and determining the optimal choice of parameters in regard to a user-defined cost-benefit function. The information obtained in testing experiments may supply us with realistic estimates of confidence and accuracy of SHA predictions. If proved reliable, but not necessarily perfect, forecast/prediction related recommendations on the level of risks in regard to engineering design, insurance, and emergency management can be used for efficient decision making.

Local Existence of MHD Contact Discontinuities

NASA Astrophysics Data System (ADS)

Morando, Alessandro; Trakhinin, Yuri; Trebeschi, Paola

2018-05-01

We prove the local-in-time existence of solutions with a contact discontinuity of the equations of ideal compressible magnetohydrodynamics (MHD) for two dimensional planar flows provided that the Rayleigh-Taylor sign condition {[partial p/partial N] <0 } on the jump of the normal derivative of the pressure is satisfied at each point of the initial discontinuity. MHD contact discontinuities are characteristic discontinuities with no flow across the discontinuity for which the pressure, the magnetic field and the velocity are continuous whereas the density and the entropy may have a jump. This paper is a natural completion of our previous analysis (Morando et al. in J Differ Equ 258:2531-2571, 2015) where the well-posedness in Sobolev spaces of the linearized problem was proved under the Rayleigh-Taylor sign condition satisfied at each point of the unperturbed discontinuity. The proof of the resolution of the nonlinear problem given in the present paper follows from a suitable tame a priori estimate in Sobolev spaces for the linearized equations and a Nash-Moser iteration.

Interactions of flavoured oil in-water emulsions with polylactide.

PubMed

Salazar, Rómulo; Domenek, Sandra; Ducruet, Violette

2014-04-01

Polylactide (PLA), a biobased polymer, might prove suitable as eco-friendly packaging, if it proves efficient at maintaining food quality. To assess interactions between PLA and food, an oïl in-water model emulsion was formulated containing aroma compounds representing different chemical structure classes (ethyl esters, 2-nonanone, benzaldehyde) at a concentration typically found in foodstuff (100 ppm). To study non-equilibrium effects during food shelf life, the emulsions were stored in a PLA pack (tray and lid). To assess equilibrium effects, PLA was conditioned in vapour contact with the aroma compounds at concentrations comparable to headspace conditions of real foods. PLA/emulsion interactions showed minor oil and aroma compound sorption in the packaging. Among tested aroma compounds, benzaldehyde and ethyl acetate were most sorbed and preferentially into the lid through the emulsion headspace. Equilibrium effects showed synergy of ethyl acetate and benzaldehyde, favouring sorption of additional aroma compounds in PLA. This should be anticipated during the formulation of food products. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nitrogen and phosphorus removal coupled with carbohydrate production by five microalgae cultures cultivated in biogas slurry.

PubMed

Tan, Fen; Wang, Zhi; Zhouyang, Siyu; Li, Heng; Xie, Youping; Wang, Yuanpeng; Zheng, Yanmei; Li, Qingbiao

2016-12-01

In this study, five microalgae strains were cultured for their ability to survive in biogas slurry, remove nitrogen resources and accumulate carbohydrates. It was proved that five microalgae strains adapted in biogas slurry well without ammonia inhibition. Among them, Chlorella vulgaris ESP-6 showed the best performance on carbohydrate accumulation, giving the highest carbohydrate content of 61.5% in biogas slurry and the highest ammonia removal efficiency and rate of 96.3% and 91.7mg/L/d respectively in biogas slurry with phosphorus and magnesium added. Additionally, the absence of phosphorus and magnesium that can be adverse for biomass accumulation resulted in earlier timing of carbohydrate accumulation and magnesium was firstly recognized and proved as the influence factor for carbohydrate accumulation. Microalgae that cultured in biogas slurry accumulated more carbohydrate in cell, making biogas slurry more suitable medium for the improvement of carbohydrate content, thus can be regarded as a new strategy to accumulate carbohydrate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimisation and validation of the analytical procedure for the determination of acrylamide in coffee by LC-MS/MS with SPE clean up.

PubMed

Gielecińska, Iwona; Mojska, Hanna

2013-01-01

Numerous studies have demonstrated acrylamide to be both neurotoxic and carcinogenic. At present it is widely recognised that acrylamide is mainly formed through the Maillard reaction from free asparagine and reducing sugars. The major sources of dietary acrylamide are potato products, processed cereals and coffee. To optimise and validate an analytical method for determining acrylamide in coffee by liquid chromatography and tandem mass spectrometry analysis (LC/MS/MS) using SPE clean-up. Analytical separation of acrylamide from roasted coffee was performed by liquid chromatography using a Hypercarb column followed by LC/MS/MS analysis, with 2,3,3-d3 acrylamide as an internal standard. The method was based on two purification steps: the first with hexane and Carrez solutions in order to remove of fat and to precipitate proteins, respectively; and the second with a solid-phase extraction (SPE) column which proved to be efficient in the elimination of the main chromatographic interferences. Limit of quantification (LOQ) for measuring acrylamide in coffee was 50 microg/kg. The described method demonstrates satisfactory precision (RSD = 2.5%), repeatability (RSD = 9.2%) and accuracy (mean recovery - 97.4%). Our results confirm that LC-MS/MS with SPE clean-up is selective and suitable for determination of acrylamide in coffee. Indeed, this method meets the criteria of EU Commission Recommendations (No. 2007/331/EC and No. 2010/307/EU), on the monitoring of acrylamide levels in food.

Measuring the arterial-induced skin vibration by geometrical moiré fringe

NASA Astrophysics Data System (ADS)

Chiu, Shih-Yung; Wang, Chun-Hsiung; Lee, Shu-Sheng; Wu, Wen-Jong; Hsu, Yu-Hsiang; Lee, Chih-Kung

2018-02-01

The demand for self-measured blood pressure self-monitoring device has much increased due to cardiovascular diseases have become leading causes of death for aging population. Currently, the primary non-invasive blood pressure monitoring method is cuff-based. It is well developed and accurate. However, the measuring process is not comfortable, and it cannot provide a continuous measurement. To overcome this problem, methods such as tonometry, volume clamp method, photoplethysmography, pulse wave velocity, and pulse transit time are reported. However, the limited accuracy hindered its application for diagnostics. To perform sequential blood pressure measurement with a high accuracy and long-term examination, we apply moiré interferometry to measure wrist skin vibration induced by radial artery. To achieve this goal, we developed a miniaturized device that can perform moiré interferometry around the wrist region. The 0.4-mm-pitched binary grating and tattoo sticker with 0.46 mm-pitched stripe pattern are used to perform geometric moiré. We demonstrated that the sensitivity and accuracy of this integrated system were sufficient to monitor arterialinduced skin vibration non-invasively. Our developed system was validated with ECG signals collected by a commercial system. According to our studies from measurement, the repeatability of wrist pulsation measurement was achieved with an accuracy of 99.1% in heart rate. A good repeatability of wrist pulse measurement was achieved. Simulations and experiments are both conducted in this paper and prove of geometrical moiré method a suitable technique for arterial-induced skin vibration monitoring.

Quantification of citalopram or escitalopram and their demethylated metabolites in neonatal hair samples by liquid chromatography-tandem mass spectrometry.

PubMed

Frison, Giampietro; Favretto, Donata; Vogliardi, Susanna; Terranova, Claudio; Ferrara, Santo Davide

2008-08-01

Citalopram and escitalopram are highly selective serotonin reuptake inhibitors widely used in the treatment of depression. They exhibit adverse drug reactions and side effects, however, and the development of specific methods for their determination is of great interest in clinical and forensic toxicology. A liquid chromatography-tandem mass spectrometry method has been developed and validated for the assay of citalopram, escitalopram, and their demethylated metabolites in 10-mg hair samples. The analytes were extracted by incubation in methanol and liquid/liquid extraction with diethyl ether/dichloromethane. Gradient elution on a narrow bore C18 column was realized using clomipramine-d3 as an internal standard. Positive ion electrospray ionization and tandem mass spectrometry determination by collision-induced dissociation were performed in an ion trap mass spectrometer. The method exhibited a linear range of 25 to 2000 pg/mg, a quantification limit of 25 pg/mg for all analytes, relative standard deviations in the range of 12.10 to 9.80 (intraassay), and 13.80 to 11.78 (interassay), and accuracies (as percent recovery of the spiked standards) in the range of 90% to 110%; it was applied to the determination of citalopram and escitalopram and their metabolites in hair samples of two newborns to document their in utero exposure to the drugs. The method proved suitable for neonatal hair analysis of citalopram or escitalopram and was applied to two real cases of gestational exposure.

Application of Visible/Near-Infrared Spectroscopy in the Prediction of Azodicarbonamide in Wheat Flour.

PubMed

Che, Wenkai; Sun, Laijun; Zhang, Qian; Zhang, Dan; Ye, Dandan; Tan, Wenyi; Wang, Lekai; Dai, Changjun

2017-10-01

Azodicarbonamide is wildly used in flour industry as a flour gluten fortifier in many countries, but it was proved by some researches to be dangerous or unhealthy for people and not suitable to be added in flour. Applying a rapid, convenient, and noninvasive technique in food analytical procedure for the safety inspection has become an urgent need. This paper used Vis/NIR reflectance spectroscopy analysis technology, which is based on the physical property analysis to predict the concentration of azodicarbonamide in flour. Spectral data in range from 400 to 2498 nm were obtained by scanning 101 samples which were prepared using the stepwise dilution method. Furthermore, the combination of leave-one-out cross-validation and Mahalanobis distance method was used to eliminate abnormal spectral data, and correlation coefficient method was used to choose characteristic wavebands. Partial least squares, back propagation neural network, and radial basis function were used to establish prediction model separately. By comparing the prediction results between 3 models, the radial basis function model has the best prediction results whose correlation coefficients (R), root mean square error of prediction (RMSEP), and ratio of performance to deviation (RPD) reached 0.99996, 0.5467, and 116.5858, respectively. Azodicarbonamide has been banned or limited in many countries. This paper proposes a method to predict azodicarbonamide concentrate in wheat flour, which will be used for a rapid, convenient, and noninvasive detection device. © 2017 Institute of Food Technologists®.

Security Modeling and Correctness Proof Using Specware and Isabelle

DTIC Science & Technology

2008-12-01

proving requires substantial knowledge and experience in logical calculus . 15. NUMBER OF PAGES 146 14. SUBJECT TERMS Formal Method, Theorem...although the actual proving requires substantial knowledge and experience in logical calculus . vi THIS PAGE INTENTIONALLY LEFT BLANK vii TABLE OF...formal language and provides tools for proving those formulas in a logical calculus ” [5]. We are demonstrating in this thesis that a specification in

Development and validation of reverse phase high performance liquid chromatography for citral analysis from essential oils.

PubMed

Gaonkar, Roopa; Yallappa, S; Dhananjaya, B L; Hegde, Gurumurthy

2016-11-15

Citral is a widely used monoterpene aldehyde in aromatherapy, food and pesticide industries. A new validated reverse phase high performance liquid chromatography (RP - HPLC) procedure for the detection and quantification of cis-trans isomers of citral was developed. The RP-HPLC analysis was carried out using Enable C - 18G column (250×4.6mm, 5μ), with acetonitrile and water (70: 30) mobile phase in isocratic mode at 1mL/min flow. A photodiode array (PDA) detector was set at 233nm for the detection of citral. The method showed linearity, selectivity and accuracy for citral in the range of 3-100μg/mL. In order to compare the new RP-HPLC method with the available methods, one of the commercially available essential oil from Cymbopogon flexuosus was analyzed using new RP-HPLC method and the same was analyzed using GC-MS for the comparison of the method for the detection of citral. The GC-MS analysis was done using mass selective detector (MSD) showed citral content to be of 72.76%; wherein the new method showed to contain that same at 74.98%. To prove the application of the new method, essential oils were extracted from lemongrass, lemon leaves and mosambi peels by steam distillation. The citral content present in the essential and also in the condensate was analyzed. The method was found to be suitable for the analysis of citral in essential oils and water based citral formulations with a very good resolution of its components geranial and neral. Copyright © 2016 Elsevier B.V. All rights reserved.

Fully automated analytical procedure for propofol determination by sequential injection technique with spectrophotometric and fluorimetric detections.

PubMed

Šrámková, Ivana; Amorim, Célia G; Sklenářová, Hana; Montenegro, Maria C B M; Horstkotte, Burkhard; Araújo, Alberto N; Solich, Petr

2014-01-01

In this work, an application of an enzymatic reaction for the determination of the highly hydrophobic drug propofol in emulsion dosage form is presented. Emulsions represent a complex and therefore challenging matrix for analysis. Ethanol was used for breakage of a lipid emulsion, which enabled optical detection. A fully automated method based on Sequential Injection Analysis was developed, allowing propofol determination without the requirement of tedious sample pre-treatment. The method was based on spectrophotometric detection after the enzymatic oxidation catalysed by horseradish peroxidase and subsequent coupling with 4-aminoantipyrine leading to a coloured product with an absorbance maximum at 485 nm. This procedure was compared with a simple fluorimetric method, which was based on the direct selective fluorescence emission of propofol in ethanol at 347 nm. Both methods provide comparable validation parameters with linear working ranges of 0.005-0.100 mg mL(-1) and 0.004-0.243 mg mL(-1) for the spectrophotometric and fluorimetric methods, respectively. The detection and quantitation limits achieved with the spectrophotometric method were 0.0016 and 0.0053 mg mL(-1), respectively. The fluorimetric method provided the detection limit of 0.0013 mg mL(-1) and limit of quantitation of 0.0043 mg mL(-1). The RSD did not exceed 5% and 2% (n=10), correspondingly. A sample throughput of approx. 14 h(-1) for the spectrophotometric and 68 h(-1) for the fluorimetric detection was achieved. Both methods proved to be suitable for the determination of propofol in pharmaceutical formulation with average recovery values of 98.1 and 98.5%. © 2013 Elsevier B.V. All rights reserved.

Boundedness and global existence in the higher-dimensional parabolic-parabolic chemotaxis system with/without growth source

NASA Astrophysics Data System (ADS)

Xiang, Tian

2015-06-01

In this paper, we are concerned with a general class of quasilinear parabolic-parabolic chemotaxis systems with/without growth source, under homogeneous Neumann boundary conditions in a smooth bounded domain Ω ⊂Rn with n ≥ 2. It is recently known that blowup is possible even in the presence of superlinear growth restrictions. Here, we derive new and interesting characterizations on the growth versus the boundedness. We show that the hard task of proving the L∞-boundedness of the cell density can be reduced to proving its Lr-boundedness. In other words, we show that the Lr-boundedness of the cell density can successfully guarantee its L∞-boundedness and hence its global boundedness, where r = n + ɛ or n/2 + ɛ depending on whether the growth restriction is essentially linear (including no growth) or superlinear. Hence, a blowup solution also blows up in Lp-norm for any suitably large p. More detailed information on how the growth source affects the boundedness of the solution is derived. These results reveal deep understandings of blowup mechanism for chemotaxis models. Then we use these criteria to establish uniform boundedness and hence global existence of the underlying models: logistic source in 2-D, cubic source as initially proposed by Mimura and Tsujikawa in 3-D, [ (n - 1) + ɛ ]st source in n-D with n ≥ 4. As a consequence, in a chemotaxis-growth model, blowup is impossible if the growth effect is suitably strong. Finally, we underline that our results remove the commonly assumed convexity on the domain Ω.

The postulations á la D’Alembert and á la Cauchy for higher gradient continuum theories are equivalent: a review of existing results

PubMed Central

Seppecher, P.

2015-01-01

In order to found continuum mechanics, two different postulations have been used. The first, introduced by Lagrange and Piola, starts by postulating how the work expended by internal interactions in a body depends on the virtual velocity field and its gradients. Then, by using the divergence theorem, a representation theorem is found for the volume and contact interactions which can be exerted at the boundary of the considered body. This method assumes an a priori notion of internal work, regards stress tensors as dual of virtual displacements and their gradients, deduces the concept of contact interactions and produces their representation in terms of stresses using integration by parts. The second method, conceived by Cauchy and based on the celebrated tetrahedron argument, starts by postulating the type of contact interactions which can be exerted on the boundary of every (suitably) regular part of a body. Then it proceeds by proving the existence of stress tensors from a balance-type postulate. In this paper, we review some relevant literature on the subject, discussing how the two postulations can be reconciled in the case of higher gradient theories. Finally, we underline the importance of the concept of contact surface, edge and wedge s-order forces. PMID:26730215

Determination of phenol compounds in surface water matrices by bar adsorptive microextraction-high performance liquid chromatography-diode array detection.

PubMed

Neng, Nuno R; Nogueira, José M F

2014-07-03

Bar adsorptive microextraction combined with liquid desorption followed by high performance liquid chromatography with diode array detection (BAµE-LD/HPLC-DAD) is proposed for the determination of trace levels of five phenol compounds (3-nitrophenol, 4-nitrophenol, bisphenol-A, 4-n-octylphenol and 4-n-nonylphenol) in surface water matrices. By using a polystyrene-divinylbenzene copolymer (PS-DVB) sorbent phase, high selectivity and efficiency is achieved even against polydimethylsiloxane through stir bar sorptive extraction. Assays performed by BAµE(PS-DVB)-LD/HPLC-DAD on 25 mL water samples spiked at the 10.0 µg/L levels yielded recoveries over 88.0%±5.7% for all five analytes, under optimized experimental conditions. The analytical performance showed good precision (RSD<15%), detection limits of 0.25 µg/L and linear dynamic ranges (1.0-25.0 μg/L) with determination coefficient higher than 0.9904. By using the standard addition method, the application of the present method to surface water matrices allowed very good performances at the trace level. The proposed methodology proved to be a suitable alternative to monitor phenol compounds in surface water matrices, showing to be easy to implement, reliable, sensitive and requiring a low sample volume.

Simple and suitable immunosensor for β-lactam antibiotics analysis in real matrixes: milk, serum, urine.

PubMed

Merola, Giovanni; Martini, Elisabetta; Tomassetti, Mauro; Campanella, Luigi

2015-03-15

The anti-penicillin G was conjugated to avidin-peroxidase and biotin to obtain immunogen and competitor which were then used to develop a competitive immunosensor assay for the detection of penicillin G and other β-lactam antibiotics, with Kaff values of the order of 10(8) M(-1). The new immunosensor appears to afford a number of advantages in terms of sensitivity, possibility of "in situ" analysis, but especially of simplicity and lower costs, compared with other existing devices, or different chemical instrumental methods reported in the literature and used for the analysis of β-lactam compounds. Satisfactory results were found in the analysis of real matrixes and good recoveries were obtained by applying the standard addition method to spiked milk, urine, serum and drug samples. The new device uses an amperometric electrode for hydrogen peroxide as transducer, the BSA-penicillin G immobilized on polymeric membrane overlapping the amperometric transducer and the peroxidase enzyme as marker. It proved to be highly sensitive, inexpensive and easily reproducible; LOD was of the order of 10(-11)M. Lastly, the new immunosensor displayed low selectivity versus the entire class of β-lactam antibiotics and higher selectivity toward other classes of non-β-lactam antibiotics. Copyright © 2014 Elsevier B.V. All rights reserved.

A novel electrochemical sensor based on FeS anchored reduced graphene oxide nanosheets for simultaneous determination of dopamine and acetaminophen.

PubMed

Liu, Xiaoya; Shangguan, Enbo; Li, Jing; Ning, Sashuang; Guo, Litan; Li, Quanmin

2017-01-01

In this paper, FeS nanoparticles anchored on reduced graphene oxide (rGO) nanosheets are synthesized via a facile direct-precipitation method. For the first time, a novel electrochemical sensor is developed based on FeS/rGO nanosheets modified glassy carbon electrode (GCE). It has been proved that the resultant FeS/rGO/GCE sensor is very suitable for the individual and simultaneous measurement of dopamine (DA) and acetaminophen (AC) and delivers excellent anti-interference ability to ascorbic acid (AA) and uric acid (UA). Under optimum conditions with differential pulse voltammetry method, a broad linear response versus the concentrations of DA and AC has been observed in the ranges of 2.0 to 250.0μM and 5.0 to 300.0μM, respectively. The detection limits for DA and AC are 0.098μM and 0.18μM, respectively. Furthermore, the as-obtained sensor has been successfully utilized in real samples and satisfactory results have been achieved. Consequently, by virtue of its outstanding electrocatalytic activity, excellent sensitivity, and long time stability, the as-obtained FeS/rGO modified electrode can be considered as a new promising DA and AC sensor. Copyright © 2016. Published by Elsevier B.V.

[Residues of chloramphenicol in the calf organism following parenteral administration of the Czechoslovak preparation Chronicin inj].

PubMed

Malíková, M; Habrda, J

1976-03-01

Using two biological methods the chloramphenicol content in various tissues of 11 calves aged 3--18 days was determined after a single-dose therapeutical administration of the Czechoslovak preparation of Chronicin inj. in the quantity of 12 mg kg-1 body mass. Of four test strains, solely Micrococcus flavus (ATCC 10240) strain proved suitable. Chloramphenicol was quantitatively determined by reading from transformed standard curves. An evalua tion of the two approximately equally sensitive methods yielded the following results: three days after the injection all calves were positive, at 5 and 10 days, one of three calves in each group was negativ similarly to both calves slaughtered 15 days post injection. The residues appeared most frequently in the liver, at the site of injection, and in the fore and hind musculature. Maximum detectable concentrations were recorded in the liver. Culinary and technological treatment of positive meat and liver samples revealed that 15 minutes' boiling and 30 minutes' roasting destroyed the microbiologically active chloramphenicol residues in the samples. Neither deep freezing nor salting was sufficient for residue inactivation, although in some samples a decrease in biological chloramphenicol activity by circa 20--30% was recorded. a preslaughter withdrawal time of 15 days is recommended.

Low Power Resistive Oxygen Sensor Based on Sonochemical SrTi0.6Fe0.4O2.8 (STFO40)

PubMed Central

Stratulat, Alisa; Serban, Bogdan-Catalin; de Luca, Andrea; Avramescu, Viorel; Cobianu, Cornel; Brezeanu, Mihai; Buiu, Octavian; Diamandescu, Lucian; Feder, Marcel; Ali, Syed Zeeshan; Udrea, Florin

2015-01-01

The current paper reports on a sonochemical synthesis method for manufacturing nanostructured (typical grain size of 50 nm) SrTi0.6Fe0.4O2.8 (Sono-STFO40) powder. This powder is characterized using X ray-diffraction (XRD), Mössbauer spectroscopy and Scanning Electron Microscopy (SEM), and results are compared with commercially available SrTi0.4Fe0.6O2.8 (STFO60) powder. In order to manufacture resistive oxygen sensors, both Sono-STFO40 and STFO60 are deposited, by dip-pen nanolithography (DPN) method, on an SOI (Silicon-on-Insulator) micro-hotplate, employing a tungsten heater embedded within a dielectric membrane. Oxygen detection tests are performed in both dry (RH = 0%) and humid (RH = 60%) nitrogen atmosphere, varying oxygen concentrations between 1% and 16% (v/v), at a constant heater temperature of 650 °C. The oxygen sensor, based on the Sono-STFO40 sensing layer, shows good sensitivity, low power consumption (80 mW), and short response time (25 s). These performance are comparable to those exhibited by state-of-the-art O2 sensors based on STFO60, thus proving Sono-STFO40 to be a material suitable for oxygen detection in harsh environments. PMID:26205267

HTS techniques for patch clamp-based ion channel screening - advances and economy.

PubMed

Farre, Cecilia; Fertig, Niels

2012-06-01

Ten years ago, the first publication appeared showing patch clamp recordings performed on a planar glass chip instead of using a conventional patch clamp pipette. "Going planar" proved to revolutionize ion channel drug screening as we know it, by allowing high quality measurements of ion channels and their effectors at a higher throughput and at the same time de-skilling the highly laborious technique. Over the years, platforms evolved in response to user requirements regarding experimental features, data handling plus storage, and suitable target diversity. This article gives a snapshot image of patch clamp-based ion channel screening with focus on platforms developed to meet requirements of high-throughput screening environments. The commercially available platforms are described, along with their benefits and drawbacks in ion channel drug screening. Automated patch clamp (APC) platforms allow faster investigation of a larger number of ion channel active compounds or cell clones than previously possible. Since patch clamp is the only method allowing direct, real-time measurements of ion channel activity, APC holds the promise of picking up high quality leads, where they otherwise would have been overseen using indirect methods. In addition, drug candidate safety profiling can be performed earlier in the drug discovery process, avoiding late-phase compound withdrawal due to safety liability issues, which is highly costly and inefficient.

Development and application of solvent-free extraction for the detection of aflatoxin M1 in dairy products by enzyme immunoassay.

PubMed

Anfossi, Laura; Calderara, Marianna; Baggiani, Claudio; Giovannoli, Cristina; Arletti, Enrico; Giraudi, Gianfranco

2008-03-26

The official methods for the quantification of aflatoxin M1 in dairy products (cheese and yogurt) include extraction into dichloromethane or chloroform, evaporation of the solvent, partitioning of the reconstituted residue with hexane, and subsequent analysis. To secure a rapid and inexpensive screen for aflatoxin M1 contamination, a sensitive competitive ELISA, using a rabbit polyclonal antibody, was developed for measuring aflatoxin M1 in milk and used in a comparative study for measuring the extraction efficiency of aflatoxin M1 in aqueous or organic solvent buffers using yogurt samples. An aqueous sodium citrate solution was found to be suitable for extracting aflatoxin M1, thus eliminating the need for organic solvents. The citrate extraction proved to be efficient (recovery ranged from 70 to 124%) in fortified samples of very different kinds of dairy products, including yogurt and six types of cheese. Fourteen yogurt and cheese samples were extracted with citrate solution and analyzed by ELISA. A good correlation was observed (y=0.95x-0.59, r2=0.98) when the data were compared with those obtained through the official method, across a wide range of aflatoxin M1 contaminations (10-200 ng/kg).

Continuous-Flow Production of Injectable Liposomes via a Microfluidic Approach

PubMed Central

Zizzari, Alessandra; Bianco, Monica; Perrone, Elisabetta; Amato, Francesco; Maruccio, Giuseppe; Rendina, Filippo; Arima, Valentina

2017-01-01

Injectable liposomes are characterized by a suitable size and unique lipid mixtures, which require time-consuming and nonstraightforward production processes. The complexity of the manufacturing methods may affect liposome solubility, the phase transition temperatures of the membranes, the average particle size, and the associated particle size distribution, with a possible impact on the drug encapsulation and release. By leveraging the precise steady-state control over the mixing of miscible liquids and a highly efficient heat transfer, microfluidic technology has proved to be an effective and direct methodology to produce liposomes. This approach results particularly efficient in reducing the number of the sizing steps, when compared to standard industrial methods. Here, Microfluidic Hydrodynamic Focusing chips were produced and used to form liposomes upon tuning experimental parameters such as lipids concentration and Flow-Rate-Ratios (FRRs). Although modelling evidenced the dependence of the laminar flow on the geometric constraints and the FRR conditions, for the specific formulation investigated in this study, the lipids concentration was identified as the primary factor influencing the size of the liposomes and their polydispersity index. This was attributed to a predominance of the bending elasticity modulus over the vesiculation index in the lipid mixture used. Eventually, liposomes of injectable size were produced using microfluidic one-pot synthesis in continuous flow. PMID:29232873

[Comparison of Discriminant Analysis and Decision Trees for the Detection of Subclinical Keratoconus].

PubMed

Kleinhans, Sonja; Herrmann, Eva; Kohnen, Thomas; Bühren, Jens

2017-08-15

Background Iatrogenic keratectasia is one of the most dreaded complications of refractive surgery. In most cases, keratectasia develops after refractive surgery of eyes suffering from subclinical stages of keratoconus with few or no signs. Unfortunately, there has been no reliable procedure for the early detection of keratoconus. In this study, we used binary decision trees (recursive partitioning) to assess their suitability for discrimination between normal eyes and eyes with subclinical keratoconus. Patients and Methods The method of decision tree analysis was compared with discriminant analysis which has shown good results in previous studies. Input data were 32 eyes of 32 patients with newly diagnosed keratoconus in the contralateral eye and preoperative data of 10 eyes of 5 patients with keratectasia after laser in-situ keratomileusis (LASIK). The control group was made up of 245 normal eyes after LASIK and 12-month follow-up without any signs of iatrogenic keratectasia. Results Decision trees gave better accuracy and specificity than did discriminant analysis. The sensitivity of decision trees was lower than the sensitivity of discriminant analysis. Conclusion On the basis of the patient population of this study, decision trees did not prove to be superior to linear discriminant analysis for the detection of subclinical keratoconus. Georg Thieme Verlag KG Stuttgart · New York.

Quantitation of polyamines in cultured cells and tissue homogenates by reversed-phase high-performance liquid chromatography of their benzoyl derivatives.

PubMed

Verkoelen, C F; Romijn, J C; Schroeder, F H; van Schalkwijk, W P; Splinter, T A

1988-04-08

A rapid and simple method, originally described by Redmond and Tseng [J. Chromatogr., 170 (1979) 479] was applied to the analysis of di- and polyamines in cultured human tumour cells and human tumour xenografts. Optimization of the procedures and evaluation of the characteristic features of the assay are described. The (modified) procedure employs precolumn derivatization with benzoyl chloride, extraction of the derivatives by chloroform, separation by reversed-phase high-performance liquid chromatography under isocratic conditions and detection by ultraviolet absorbance measurement at 229 nm. The complete analysis was accomplished within 10 min per sample. The detection limit was ca. 1 pmol. The intra- and inter-assay coefficients of variation were 2.5-4.4% and 3.4-13.1%, respectively. The presence of well known inhibitors of polyamine biosynthesis, such as DL-alpha-difluoromethylornithine and methylglyoxal bis(guanylhydrazone), did not interfere with the assay, and disturbance by cyclohexylamine could be avoided by changing the polarity of the mobile phase. The method proved to be very suitable because it is rapid, simple, requires a minimum of sample pretreatment, and still provides sufficient sensitivity to quantitate polyamines in relatively small amounts of cells (10(5) cells) or tumour tissues (less than 1 mg), even after treatment with inhibitors of polyamine biosynthesis.

A Layered Searchable Encryption Scheme with Functional Components Independent of Encryption Methods

PubMed Central

Luo, Guangchun; Qin, Ke

2014-01-01

Searchable encryption technique enables the users to securely store and search their documents over the remote semitrusted server, which is especially suitable for protecting sensitive data in the cloud. However, various settings (based on symmetric or asymmetric encryption) and functionalities (ranked keyword query, range query, phrase query, etc.) are often realized by different methods with different searchable structures that are generally not compatible with each other, which limits the scope of application and hinders the functional extensions. We prove that asymmetric searchable structure could be converted to symmetric structure, and functions could be modeled separately apart from the core searchable structure. Based on this observation, we propose a layered searchable encryption (LSE) scheme, which provides compatibility, flexibility, and security for various settings and functionalities. In this scheme, the outputs of the core searchable component based on either symmetric or asymmetric setting are converted to some uniform mappings, which are then transmitted to loosely coupled functional components to further filter the results. In such a way, all functional components could directly support both symmetric and asymmetric settings. Based on LSE, we propose two representative and novel constructions for ranked keyword query (previously only available in symmetric scheme) and range query (previously only available in asymmetric scheme). PMID:24719565

A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements

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

Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland

2016-07-15

Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signalsmore » with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.« less

Comparison of prediction methods for oxygen-18 isotope composition in shallow groundwater.

PubMed

Cerar, Sonja; Mezga, Kim; Žibret, Gorazd; Urbanc, Janko; Komac, Marko

2018-08-01

Groundwater is the most important source of drinking water in the world. Therefore, information on the quality and quantity is important, as is new information related to the characteristics of the aquifer and the recharge area. In the present study we focused on the isotope composition of oxygen (δ 18 O) in groundwater, which is a natural tracer and provides a better understanding of the water cycle, in terms of origin, dynamics and interaction. The groundwater δ 18 O at 83 locations over the entire Slovenian territory was studied. Each location was sampled twice during the period 2009-2011. Geostatistical tools (such us ordinary kriging, simple and multiple linear regressions, and artificial neural networks were used and compared to select the best tool. Measured values of δ 18 O in the groundwater were used as the dependent variable, while the spatial characteristics of the territory (elevation, distance from the sea and average annual precipitation) were used as independent variables. Based on validation data sets, the artificial neural network model proved to be the most suitable method for predicting δ 18 O in the groundwater, since it produced the smallest deviations from the real/measured values in groundwater. Copyright © 2018 Elsevier B.V. All rights reserved.

Intelligent reservoir operation system based on evolving artificial neural networks

NASA Astrophysics Data System (ADS)

Chaves, Paulo; Chang, Fi-John

2008-06-01

We propose a novel intelligent reservoir operation system based on an evolving artificial neural network (ANN). Evolving means the parameters of the ANN model are identified by the GA evolutionary optimization technique. Accordingly, the ANN model should represent the operational strategies of reservoir operation. The main advantages of the Evolving ANN Intelligent System (ENNIS) are as follows: (i) only a small number of parameters to be optimized even for long optimization horizons, (ii) easy to handle multiple decision variables, and (iii) the straightforward combination of the operation model with other prediction models. The developed intelligent system was applied to the operation of the Shihmen Reservoir in North Taiwan, to investigate its applicability and practicability. The proposed method is first built to a simple formulation for the operation of the Shihmen Reservoir, with single objective and single decision. Its results were compared to those obtained by dynamic programming. The constructed network proved to be a good operational strategy. The method was then built and applied to the reservoir with multiple (five) decision variables. The results demonstrated that the developed evolving neural networks improved the operation performance of the reservoir when compared to its current operational strategy. The system was capable of successfully simultaneously handling various decision variables and provided reasonable and suitable decisions.

Research of CO2 and N2 Adsorption Behavior in K-Illite Slit Pores by GCMC Method

PubMed Central

Chen, Guohui; Lu, Shuangfang; Zhang, Junfang; Xue, Qingzhong; Han, Tongcheng; Xue, Haitao; Tian, Shansi; Li, Jinbu; Xu, Chenxi; Pervukhina, Marina; Clennell, Ben

2016-01-01

Understanding the adsorption mechanisms of CO2 and N2 in illite, one of the main components of clay in shale, is important to improve the precision of the shale gas exploration and development. We investigated the adsorption mechanisms of CO2 and N2 in K-illite with varying pore sizes at the temperature of 333, 363 and 393 K over a broad range of pressures up to 30 MPa using the grand canonical Monte Carlo (GCMC) simulation method. The simulation system is proved to be reasonable and suitable through the discussion of the impact of cation dynamics and pore wall thickness. The simulation results of the excess adsorption amount, expressed per unit surface area of illite, is in general consistency with published experimental results. It is found that the sorption potential overlaps in micropores, leading to a decreasing excess adsorption amount with the increase of pore size at low pressure, and a reverse trend at high pressure. The excess adsorption amount increases with increasing pressure to a maximum and then decreases with further increase in the pressure, and the decreasing amount is found to increase with the increasing pore size. For pores with size greater larger than 2 nm, the overlap effect disappears. PMID:27897232

Identification of suitable sites for mountain ginseng cultivation using GIS and geo-temperature.

PubMed

Kang, Hag Mo; Choi, Soo Im; Kim, Hyun

2016-01-01

This study was conducted to explore an accurate site identification technique using a geographic information system (GIS) and geo-temperature (gT) for locating suitable sites for growing cultivated mountain ginseng (CMG; Panax ginseng), which is highly sensitive to the environmental conditions in which it grows. The study site was Jinan-gun, South Korea. The spatial resolution for geographic data was set at 10 m × 10 m, and the temperatures for various climatic factors influencing CMG growth were calculated by averaging the 3-year temperatures obtained from the automatic weather stations of the Korea Meteorological Administration. Identification of suitable sites for CMG cultivation was undertaken using both a conventional method and a new method, in which the gT was added as one of the most important factors for crop cultivation. The results yielded by the 2 methods were then compared. When the gT was added as an additional factor (new method), the proportion of suitable sites identified decreased by 0.4 % compared with the conventional method. However, the proportion matching real CMG cultivation sites increased by 3.5 %. Moreover, only 68.2 % corresponded with suitable sites identified using the conventional factors; i.e., 31.8 % were newly detected suitable sites. The accuracy of GIS-based identification of suitable CMG cultivation sites improved by applying the temperature factor (i.e., gT) in addition to the conventionally used factors.

Estimating Rooftop Suitability for PV: A Review of Methods, Patents, and Validation Techniques

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

Melius, J.; Margolis, R.; Ong, S.

2013-12-01

A number of methods have been developed using remote sensing data to estimate rooftop area suitable for the installation of photovoltaics (PV) at various geospatial resolutions. This report reviews the literature and patents on methods for estimating rooftop-area appropriate for PV, including constant-value methods, manual selection methods, and GIS-based methods. This report also presents NREL's proposed method for estimating suitable rooftop area for PV using Light Detection and Ranging (LiDAR) data in conjunction with a GIS model to predict areas with appropriate slope, orientation, and sunlight. NREL's method is validated against solar installation data from New Jersey, Colorado, and Californiamore » to compare modeled results to actual on-the-ground measurements.« less

The development of the Problematic Online Gaming Questionnaire (POGQ).

PubMed

Demetrovics, Zsolt; Urbán, Róbert; Nagygyörgy, Katalin; Farkas, Judit; Griffiths, Mark D; Pápay, Orsolya; Kökönyei, Gyöngyi; Felvinczi, Katalin; Oláh, Attila

2012-01-01

Online gaming has become increasingly popular. However, this has led to concerns that these games might induce serious problems and/or lead to dependence for a minority of players. The aim of this study was to uncover and operationalize the components of problematic online gaming. A total of 3415 gamers (90% males; mean age 21 years), were recruited through online gaming websites. A combined method of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) was applied. Latent profile analysis was applied to identify persons at-risk. EFA revealed a six-factor structure in the background of problematic online gaming that was also confirmed by a CFA. For the assessment of the identified six dimensions--preoccupation, overuse, immersion, social isolation, interpersonal conflicts, and withdrawal--the 18-item Problematic Online Gaming Questionnaire (POGQ) proved to be exceedingly suitable. Based on the latent profile analysis, 3.4% of the gamer population was considered to be at high risk, while another 15.2% was moderately problematic. The POGQ seems to be an adequate measurement tool for the differentiated assessment of gaming related problems on six subscales.

[Public health: politics help those who help themselves [in health services

PubMed

Ortún, Vicente

2007-01-01

Poor countries health improves with the application of public health knowledge, but this requires from institutional capacity and political will, not automatically guaranteed by income growth alone. Generalized cost-benefit analysis, explicit establishment of priorities and even consensus (knowledge sharing) are suitable methods to select appropriate policies. Some problems, such as the increasing inequalities among countries or the global warming, may require a change of our institutions given than both market mechanisms and traditional policy intervention by nation-states may prove insufficient. could be the motto for the necessary conciliation between individual and collective actions on health. It has a similar importance to act upon the differences between individuals with similar exposures as diminishing the global risk of those social groups where misfortunes cluster. In a country such a Spain the aforementioned conciliation happens though a Welfare State capable of achieving social 'desirability' based upon democratic legitimacy and effective behavior, effectiveness that can not be obtained without the best combination of clinical and Public Health interventions.

Fourier-transformed infrared breath testing after ingestion of technical alcohol.

PubMed

Laakso, Olli; Haapala, Matti; Pennanen, Teemu; Kuitunen, Tapio; Himberg, Jaakko-Juhani

2007-07-01

The study aim was to evaluate the feasibility of a Fourier-transformed infrared (FT-IR) analyzer for out-of-laboratory use by screening the exhalations of inebriated individuals, and to determine analysis quality using common breath components and solvents. Each of the 35 inebriated participants gave an acceptable sample. Because of the metabolism of 2-propanol, the subjects exhaled high concentrations of acetone in addition to ethanol. Other volatile ingredients of technical ethanol products (methyl ethyl ketone, methyl isobutyl ketone, and 2-propanol) were also detected. The lower limits of quantification for the analyzed components ranged from 1.7 to 12 microg/L in simulated breath samples. The bias was +/-2% for ethanol and -11% for methanol. Within-day and between-day coefficients of variation were <1% for ethanol and <4% for methanol. The bias of ethanol and methanol analyses due to coexisting solvents ranged from -0.8 to +2.2% and from -5.6 to +2.9%, respectively. The FT-IR method proved suitable for use outside the laboratory and fulfilled the quality criteria for analysis of solvents in breath.

Engineered Aptamers to Probe Molecular Interactions on the Cell Surface

PubMed Central

Batool, Sana; Bhandari, Sanam; George, Shanell; Okeoma, Precious; Van, Nabeela; Zümrüt, Hazan E.; Mallikaratchy, Prabodhika

2017-01-01

Significant progress has been made in understanding the nature of molecular interactions on the cell membrane. To decipher such interactions, molecular scaffolds can be engineered as a tool to modulate these events as they occur on the cell membrane. To guarantee reliability, scaffolds that function as modulators of cell membrane events must be coupled to a targeting moiety with superior chemical versatility. In this regard, nucleic acid aptamers are a suitable class of targeting moieties. Aptamers are inherently chemical in nature, allowing extensive site-specific chemical modification to engineer sensing molecules. Aptamers can be easily selected using a simple laboratory-based in vitro evolution method enabling the design and development of aptamer-based functional molecular scaffolds against wide range of cell surface molecules. This article reviews the application of aptamers as monitors and modulators of molecular interactions on the mammalian cell surface with the aim of increasing our understanding of cell-surface receptor response to external stimuli. The information gained from these types of studies could eventually prove useful in engineering improved medical diagnostics and therapeutics. PMID:28850067

Biotin-streptavidin enzyme-linked immunosorbent assay for detecting Tetrabromobisphenol A in electronic waste.

PubMed

Bu, Dan; Zhuang, Huisheng; Zhou, Xinchu; Yang, Guangxin

2014-03-01

Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant. A sensitive and selective indirect competitive biotin-streptavidin-amplified enzyme-linked immunosorbent assay (BA-ELISA) was developed for detecting TBBPA. The optimal hapten of TBBPA was 2-(2,6-dibromo-4-(2-(3,5-dibromo-4-hydroxyphenly)propan-2-yl)) acetic acid. Several physiochemical factors that influence assay performance, such as optimal coupling concentration of immunogen and antibody, organic solvent, ionic strength, and pH, were studied and optimized. The limit of detection (IC10) was 0.027 ng/mL and the median inhibitory concentration (IC50) was 0.58 ng/mL. The BA-ELISA was highly selective, with low cross-reactivity with TBBPA analogs. Finally, the assay was used to detect TBBPA in electronic waste samples. The results are consistent with those using liquid chromatography, which proves that the proposed immunoassay is accurate and receptive. This BA-ELISA method is suitable for the rapid and sensitive screening of TBBPA in environmental monitoring. © 2013 Published by Elsevier B.V.

Orbital Advection with Magnetohydrodynamics and Vector Potential

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

Lyra, Wladimir; McNally, Colin P.; Heinemann, Tobias

Orbital advection is a significant bottleneck in disk simulations, and a particularly tricky one when used in connection with magnetohydrodynamics. We have developed an orbital advection algorithm suitable for the induction equation with magnetic potential. The electromotive force is split into advection and shear terms, and we find that we do not need an advective gauge since solving the orbital advection implicitly precludes the shear term from canceling the advection term. We prove and demonstrate the third order in time accuracy of the scheme. The algorithm is also suited to non-magnetic problems. Benchmarked results of (hydrodynamical) planet–disk interaction and ofmore » the magnetorotational instability are reproduced. We include detailed descriptions of the construction and selection of stabilizing dissipations (or high-frequency filters) needed to generate practical results. The scheme is self-consistent, accurate, and elegant in its simplicity, making it particularly efficient for straightforward finite-difference methods. As a result of the work, the algorithm is incorporated in the public version of the Pencil Code, where it can be used by the community.« less

Operation of electrothermal and electrostatic MUMPs microactuators underwater

NASA Astrophysics Data System (ADS)

Sameoto, Dan; Hubbard, Ted; Kujath, Marek

2004-10-01

Surface-micromachined actuators made in multi-user MEMS processes (MUMPs) have been operated underwater without modifying the manufacturing process. Such actuators have generally been either electro-thermally or electro-statically actuated and both actuator styles are tested here for suitability underwater. This is believed to be the first time that thermal and electrostatic actuators have been compared for deflection underwater relative to air performance. A high-frequency ac square wave is used to replicate a dc-driven actuator output without the associated problem of electrolysis in water. This method of ac activation, with frequencies far above the mechanical resonance frequencies of the MEMS actuators, has been termed root mean square (RMS) operation. Both thermal and electrostatic actuators have been tested and proved to work using RMS control. Underwater performance has been evaluated by using in-air operation of these actuators as a benchmark. When comparing deflection per volt applied, thermal actuators operate between 5 and 9% of in-air deflection and electrostatic actuators show an improvement in force per volt applied of upwards of 6000%. These results agree with predictions based on the physical properties of the surrounding medium.

Virtual Distances Methodology as Verification Technique for AACMMs with a Capacitive Sensor Based Indexed Metrology Platform

PubMed Central

Acero, Raquel; Santolaria, Jorge; Brau, Agustin; Pueo, Marcos

2016-01-01

This paper presents a new verification procedure for articulated arm coordinate measuring machines (AACMMs) together with a capacitive sensor-based indexed metrology platform (IMP) based on the generation of virtual reference distances. The novelty of this procedure lays on the possibility of creating virtual points, virtual gauges and virtual distances through the indexed metrology platform’s mathematical model taking as a reference the measurements of a ball bar gauge located in a fixed position of the instrument’s working volume. The measurements are carried out with the AACMM assembled on the IMP from the six rotating positions of the platform. In this way, an unlimited number and types of reference distances could be created without the need of using a physical gauge, therefore optimizing the testing time, the number of gauge positions and the space needed in the calibration and verification procedures. Four evaluation methods are presented to assess the volumetric performance of the AACMM. The results obtained proved the suitability of the virtual distances methodology as an alternative procedure for verification of AACMMs using the indexed metrology platform. PMID:27869722

Surface modification of polyethylene/graphene composite using corona discharge

NASA Astrophysics Data System (ADS)

Popelka, Anton; Noorunnisa Khanam, P.; AlMaadeed, Mariam Ali

2018-03-01

Polyethylene/graphene composites are suitable for electromagnetic interference shielding applications and are often fabricated as sandwich structures. However, the hydrophobic character of these composites can lead to delamination. Corona treatment was used to enhance the surface hydrophilicity of composites prepared from linear low-density polyethylene (LLDPE) and graphene nanoplatelets (GNPs) with different content (2, 4, 6, and 8 wt.%). This enhancement of wettability also led to good adhesion properties. The presence of GNPs in LLDPE had a positive effect on the surface properties after corona treatment. The surface free energy of the LLDPE/GNP composites increased by almost 64.6% for 2 wt.% of GNPs in the LLDPE/GNP composite, while the surface free energy of neat LLDPE increased by only 38.1%. The best improvement in adhesion properties after corona treatment was observed for 2 wt.% of GNPs in the LLDPE/GNP composite, while peel resistance increased by 137.9%. Various analytical techniques and methods proved that the changes in the surface morphology and chemical composition of the LLDPE/GNP composite after this treatment resulted in an improvement of adhesion.

Dynamics and spatio-temporal variability of environmental factors in Eastern Australia using functional principal component analysis

USGS Publications Warehouse

Szabo, J.K.; Fedriani, E.M.; Segovia-Gonzalez, M. M.; Astheimer, L.B.; Hooper, M.J.

2010-01-01

This paper introduces a new technique in ecology to analyze spatial and temporal variability in environmental variables. By using simple statistics, we explore the relations between abiotic and biotic variables that influence animal distributions. However, spatial and temporal variability in rainfall, a key variable in ecological studies, can cause difficulties to any basic model including time evolution. The study was of a landscape scale (three million square kilometers in eastern Australia), mainly over the period of 19982004. We simultaneously considered qualitative spatial (soil and habitat types) and quantitative temporal (rainfall) variables in a Geographical Information System environment. In addition to some techniques commonly used in ecology, we applied a new method, Functional Principal Component Analysis, which proved to be very suitable for this case, as it explained more than 97% of the total variance of the rainfall data, providing us with substitute variables that are easier to manage and are even able to explain rainfall patterns. The main variable came from a habitat classification that showed strong correlations with rainfall values and soil types. ?? 2010 World Scientific Publishing Company.

Virtual Distances Methodology as Verification Technique for AACMMs with a Capacitive Sensor Based Indexed Metrology Platform.

PubMed

Acero, Raquel; Santolaria, Jorge; Brau, Agustin; Pueo, Marcos

2016-11-18

This paper presents a new verification procedure for articulated arm coordinate measuring machines (AACMMs) together with a capacitive sensor-based indexed metrology platform (IMP) based on the generation of virtual reference distances. The novelty of this procedure lays on the possibility of creating virtual points, virtual gauges and virtual distances through the indexed metrology platform's mathematical model taking as a reference the measurements of a ball bar gauge located in a fixed position of the instrument's working volume. The measurements are carried out with the AACMM assembled on the IMP from the six rotating positions of the platform. In this way, an unlimited number and types of reference distances could be created without the need of using a physical gauge, therefore optimizing the testing time, the number of gauge positions and the space needed in the calibration and verification procedures. Four evaluation methods are presented to assess the volumetric performance of the AACMM. The results obtained proved the suitability of the virtual distances methodology as an alternative procedure for verification of AACMMs using the indexed metrology platform.

Approach to in-process tool wear monitoring in drilling: Application of Kalman filter theory

NASA Astrophysics Data System (ADS)

He, Ning; Zhang, Youzhen; Pan, Liangxian

1993-05-01

The two parameters often used in adaptive control, tool wear and wear rate, are the important factors affecting machinability. In this paper, it is attempted to use the modern cybernetics to solve the in-process tool wear monitoring problem by applying the Kalman filter theory to monitor drill wear quantitatively. Based on the experimental results, a dynamic model, a measuring model and a measurement conversion model suitable for Kalman filter are established. It is proved that the monitoring system possesses complete observability but does not possess complete controllability. A discriminant for selecting the characteristic parameters is put forward. The thrust force Fz is selected as the characteristic parameter in monitoring the tool wear by this discriminant. The in-process Kalman filter drill wear monitoring system composed of force sensor microphotography and microcomputer is well established. The results obtained by the Kalman filter, the common indirect measuring method and the real drill wear measured by the aid of microphotography are compared. The result shows that the Kalman filter has high precision of measurement and the real time requirement can be satisfied.