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Sample records for rapid phase rate

  1. A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes

    Science.gov (United States)

    Fridlin, Ann; vanDiedenhoven, Bastiaan; Ackerman, Andrew S.; Avramov, Alexander; Mrowiec, Agnieszka; Morrison, Hugh; Zuidema, Paquita; Shupe, Matthew D.

    2012-01-01

    Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)Arctic Cloud Experiment (ACE)Surface Heat Budget of the Arctic Ocean (SHEBA) campaign provide a unique opportunity to test understanding of cloud ice formation. Under the microphysically simple conditions observed (apparently negligible ice aggregation, sublimation, and multiplication), the only expected source of new ice crystals is activation of heterogeneous ice nuclei (IN) and the only sink is sedimentation. Large-eddy simulations with size-resolved microphysics are initialized with IN number concentration N(sub IN) measured above cloud top, but details of IN activation behavior are unknown. If activated rapidly (in deposition, condensation, or immersion modes), as commonly assumed, IN are depleted from the well-mixed boundary layer within minutes. Quasi-equilibrium ice number concentration N(sub i) is then limited to a small fraction of overlying N(sub IN) that is determined by the cloud-top entrainment rate w(sub e) divided by the number-weighted ice fall speed at the surface v(sub f). Because w(sub c) 10 cm/s, N(sub i)/N(sub IN)<< 1. Such conditions may be common for this cloud type, which has implications for modeling IN diagnostically, interpreting measurements, and quantifying sensitivity to increasing N(sub IN) (when w(sub e)/v(sub f)< 1, entrainment rate limitations serve to buffer cloud system response). To reproduce observed ice crystal size distributions and cloud radar reflectivities with rapidly consumed IN in this case, the measured above-cloud N(sub IN) must be multiplied by approximately 30. However, results are sensitive to assumed ice crystal properties not constrained by measurements. In addition, simulations do not reproduce the pronounced mesoscale heterogeneity in radar reflectivity that is observed.

  2. A rapid molecular approach for chromosomal phasing.

    Directory of Open Access Journals (Sweden)

    John F Regan

    Full Text Available Determining the chromosomal phase of pairs of sequence variants - the arrangement of specific alleles as haplotypes - is a routine challenge in molecular genetics. Here we describe Drop-Phase, a molecular method for quickly ascertaining the phase of pairs of DNA sequence variants (separated by 1-200 kb without cloning or manual single-molecule dilution. In each Drop-Phase reaction, genomic DNA segments are isolated in tens of thousands of nanoliter-sized droplets together with allele-specific fluorescence probes, in a single reaction well. Physically linked alleles partition into the same droplets, revealing their chromosomal phase in the co-distribution of fluorophores across droplets. We demonstrated the accuracy of this method by phasing members of trios (revealing 100% concordance with inheritance information, and demonstrate a common clinical application by phasing CFTR alleles at genomic distances of 11-116 kb in the genomes of cystic fibrosis patients. Drop-Phase is rapid (requiring less than 4 hours, scalable (to hundreds of samples, and effective at long genomic distances (200 kb.

  3. Potent, transient inhibition of BCR-ABL with dasatinib 100 mg daily achieves rapid and durable cytogenetic responses and high transformation-free survival rates in chronic phase chronic myeloid leukemia patients with resistance, suboptimal response or intolerance to imatinib

    Science.gov (United States)

    Shah, Neil P.; Kim, Dong-Wook; Kantarjian, Hagop; Rousselot, Philippe; Llacer, Pedro Enrique Dorlhiac; Enrico, Alicia; Vela-Ojeda, Jorge; Silver, Richard T.; Khoury, Hanna Jean; Müller, Martin C.; Lambert, Alexandre; Matloub, Yousif; Hochhaus, Andreas

    2010-01-01

    Background Dasatinib 100 mg once daily achieves intermittent BCR-ABL kinase inhibition and is approved for chronic-phase chronic myeloid leukemia patients resistant or intolerant to imatinib. To better assess durability of response to and tolerability of dasatinib, data from a 2-year minimum follow-up for a dose-optimization study in chronic-phase chronic myeloid leukemia are reported here. Design and Methods In a phase 3 study, 670 chronic-phase chronic myeloid leukemia patients with resistance, intolerance, or suboptimal response to imatinib were randomized to dasatinib 100 mg once-daily, 50 mg twice-daily, 140 mg once-daily, or 70 mg twice-daily. Results Data from a 2-year minimum follow-up demonstrate that dasatinib 100 mg once daily achieves major cytogenetic response and complete cytogenetic response rates comparable to those in the other treatment arms, and reduces the frequency of key side effects. Comparable 2-year progression-free survival and overall survival rates were observed (80% and 91%, respectively, for 100 mg once daily, and 75%–76% and 88%–94%, respectively, in other arms). Complete cytogenetic responses were achieved rapidly, typically by 6 months. In patients treated with dasatinib 100 mg once daily for 6 months without complete cytogenetic response, the likelihood of achieving such a response by 2 years was 50% for patients who had achieved a partial cytogenetic response, and only 8% or less for patients with minor, minimal, or no cytogenetic response. Less than 3% of patients suffered disease transformation to accelerated or blast phase. Conclusions Intermittent kinase inhibition can achieve rapid and durable responses, indistinguishable from those achieved with more continuous inhibition. PMID:20139391

  4. Influence of quench rates on the properties of rapidly solidified ...

    Indian Academy of Sciences (India)

    FeNbCuSiB based materials were produced in the form of ribbons by rapid solidification techniques. The crystallization, magnetic, mechanical and corrosion behaviour were studied for the prepared materials as a function of quenching rate from liquid to the solid state. Higher quench rates produced a more amorphous ...

  5. Modeling second-phase formation during rapid resolidification of stainless steel alloys

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, J.W. (Lawrence Livermore National Lab., CA (USA)); Eagar, T.W.; Allen, S.M. (Massachusetts Inst. of Tech., Cambridge, MA (USA))

    1991-01-28

    Many common stainless steel (SS) alloy microstructures consist of a mixture of ferrite and austenite phases, however, when these alloys are rapidly resolidified using laser beam (LB) or electron beam (EB) processes they solidify in the single-phase-austenite or single-phase-ferrite mode. This paper investigates the influence of solidification rate on the reduction, and eventual elimination, of second phases during the rapid solidification of SS alloys. The influence of solidification rate on the ferrite content of these alloys was studied by calculating the dendrite-tip undercooling and then incorporating these results into a solute-redistribution model to calculate the relative fractions of primary and secondary phase that solidify from the melt. Single-phase solidification was predicted at high cooling rates and was confirmed through STEM analysis, showing solidification microstructures void of any significant microchemical composition gradients. Results showed a rapid-solidification model was used to calculate the relative fractions of primary and secondary phases that form during the resolidification of stainless steel alloys. The rapid-solidification model shows that the ferrite content of primary-austenite solidified alloys decreases and the ferrite content of primary-ferrite solidified alloys increases with increasing cooling rate. Results of the model indicate that primary-austenite alloys will solidify in the single-phase mode at all interface velocities greater than about 20 mm/s. This value correlates well with experiments. Results of the model indicate that primary-ferrite alloys will solidify in the single-phase mode at all interface velocities greater than about 50 mm/s. The experimentally-observed interface velocity for single-phase-ferrite solidification is significantly less (10 mm/s). This discrepancy is proposed to be related to the relative difficulty of nucleating austenite from the eutectic liquid. 13 refs., 5 figs., 2 tabs.

  6. Are Melt Migration Rates Through the Mantle Universally Rapid?

    Science.gov (United States)

    Reagan, M. K.; Sims, K. W.

    2001-12-01

    Significant enrichments in 226Ra over 230Th have been observed in basalts erupted in nearly all tectonic settings. These enrichments generally are greatest in lavas with low concentrations of U, Th and other incompatible elements, including those from mid-ocean ridges and "depleted" volcanic arcs. Excesses of 226Ra over 230Th in mid-ocean ridge settings are commonly attributed to smaller bulk partition coefficients for Ra with respect to Th during mantle melting, and extraction of ingrown Ra into melts slowly migrating through interconnected pore space. In contrast, 226Ra excesses in basalts from volcanic arcs have been attributed to fluid additions from subducting slabs to the sources of the basalt and rapid (102 - 103y) melt migration to the surface (e.g. Turner et al., 2001). Such rapid melt velocities imply channeled flow rather than diffuse porous flow, and suggest that basalts from other tectonic settings migrate similarly rapidly. Here, we show that the compositions of basalts from both arc and mid-ocean ridge settings indeed can be explained by melting models involving rapid transit times to the surface. Simple fluxed melting models and rapid transfer of melt to the surface explain the U-Th-Ra systematics and incompatible trace element compositions of arc basalts. The U-Th-Ra and trace element data for young MORB from the East Pacific Rise (Sims et al. 2001) and the Siqueiros transform (Lundstrom et al. 1999) are modeled using simple 2-d polybaric melting based on Braun et al. (2000) and rapid melt migration rates. Successful models mix small-degree fractional melts derived from a broad cross-sectional area of mantle at depth with high-degree melts derived from a small cross-sectional area of shallow mantle that is the aged residue of the small degree melt.

  7. Influence of cooling rate on microstructure formation during rapid solidification of binary TiAl alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kenel, C., E-mail: Christoph.Kenel@empa.ch; Leinenbach, C.

    2015-07-15

    Highlights: • Rapid solidification studies with varying cooling rates were realized for Ti–Al. • Experiments were combined with finite element simulations of heat transfer. • The resulting microstructure of Ti–Al alloys is strongly dependent on the Al content. • The microstructure and phase transformation behavior can be predicted. • The method allows alloy development for processes involving rapid solidification. - Abstract: Titanium aluminides as structural intermetallics are possible candidates for a potential weight reduction and increased performance of high temperature components. A method for the characterization of the microstructure formation in rapidly solidified alloys was developed and applied for binary Ti–(44–48)Al (at.%). The results show a strong dependency of the microstructure on the Al content at cooling rates between 6 ⋅ 10{sup 2} and 1.5 ⋅ 10{sup 4} K s{sup −1}. The formation of α → α{sub 2} ordering, lamellar α{sub 2} + γ colonies and interdendritic TiAl γ-phase were observed, depending on the Al amount. Based on thermodynamic calculations the observed microstructure can be explained using the CALPHAD approach taking into account the non-equilibrium conditions. The presented method provides a useful tool for alloy development for processing techniques involving rapid solidification with varying cooling rates.

  8. A rapid method to estimate Westergren sedimentation rates

    Science.gov (United States)

    Alexy, Tamas; Pais, Eszter; Meiselman, Herbert J.

    2009-01-01

    The erythrocyte sedimentation rate (ESR) is a nonspecific but simple and inexpensive test that was introduced into medical practice in 1897. Although it is commonly utilized in the diagnosis and follow-up of various clinical conditions, ESR has several limitations including the required 60 min settling time for the test. Herein we introduce a novel use for a commercially available computerized tube viscometer that allows the accurate prediction of human Westergren ESR rates in as little as 4 min. Owing to an initial pressure gradient, blood moves between two vertical tubes through a horizontal small-bore tube and the top of the red blood cell (RBC) column in each vertical tube is monitored continuously with an accuracy of 0.083 mm. Using data from the final minute of a blood viscosity measurement, a sedimentation index (SI) was calculated and correlated with results from the conventional Westergren ESR test. To date, samples from 119 human subjects have been studied and our results indicate a strong correlation between SI and ESR values (R2=0.92). In addition, we found a close association between SI and RBC aggregation indices as determined by an automated RBC aggregometer (R2=0.71). Determining SI on human blood is rapid, requires no special training and has minimal biohazard risk, thus allowing physicians to rapidly screen for individuals with elevated ESR and to monitor therapeutic responses. PMID:19791973

  9. Amorphous Phase Formation Analysis of Rapidly Solidified CoCr Droplets

    Science.gov (United States)

    Bogno, Abdoul-Aziz; Riveros, Carlos; Henein, Hani; Li, Delin

    2016-12-01

    This paper investigates amorphous phase formation and rapid solidification characteristics of a CoCr alloy. High cooling rate and high undercooling-induced rapid solidification of the alloy was achieved by impulse atomization in helium atmosphere. Two atomization experiments were carried out to generate powders of a wide size range from liquid CoCr at two different temperatures. Amorphous fraction and kinetic crystallization properties of impulse atomized powders were systematically quantified by means of differential scanning calorimetry. In addition, different but complementary characterization tools were used to analyze the powders microstructures. The fraction of amorphous phase within the investigated powders is found to be promoted by high cooling rate or smaller powder size. The critical cooling rate for amorphous phase formation, which is influenced by the oxygen content in the melt, is found to be 3 × 104 K s-1 and corresponds to a 160- µm-diameter powder atomized in helium. Hardness of the powders is found to follow a trend that is described by the Hall-Petch relation when a relatively high fraction of crystalline structures is present and decreases with the fraction of amorphous phase.

  10. Rapid prediction of long-term rates of contaminant desorption from soils and sediments.

    Science.gov (United States)

    Johnson, M D; Weber, W J

    2001-01-15

    A method using heated and superheated (subcritical) water is described for rapid prediction of long-term desorption rates from contaminated geosorbents. Rates of contaminant release are measured at temperatures between 75 and 150 degrees C using a dynamic water desorption technique. The subcritical desorption rate data are then modeled to calculate apparent activation energies, and these activation energies are used to predict desorption behaviors at any desired ambient temperature. Predictions of long-term release rates based on this methodology were found to correlate well with experimental 25 degrees C desorption data measured over periods of up to 640 days, even though the 25 degrees C desorption rates were observed to vary by up to 2 orders of magnitude for different geosorbent types and initial solid phase contaminant loading levels. Desorption profiles measured under elevated temperature and pressure conditions closely matched those at 25 degrees C and ambient pressure, but the time scales associated with the high-temperature measurements were up to 3 orders of magnitude lower. The subcritical water technique rapidly estimates rates of desorption-resistant contaminant release as well as those for more labile substances. The practical implications of the methodology are significant because desorption observed under field conditions and ambient temperatures typically proceeds over periods of months or years, while the high temperature experiments used for prediction of such field desorption phenomena can be completed within periods of only hours or days.

  11. Influence of quench rates on the properties of rapidly solidified ...

    Indian Academy of Sciences (India)

    Unknown

    A K PANDA, I CHATTORAJ, S BASU* and A MITRA. National Metallurgical Laboratory, Jamshedpur 831 007, India. *Materials Science Centre, Indian Institute of Technology, Kharagpur 721 302, India. Abstract. FeNbCuSiB based materials were produced in the form of ribbons by rapid solidification techniques.

  12. Subsampling phase retrieval for rapid thermal measurements of heated microstructures.

    Science.gov (United States)

    Taylor, Lucas N; Talghader, Joseph J

    2016-07-15

    A subsampling technique for real-time phase retrieval of high-speed thermal signals is demonstrated with heated metal lines such as those found in microelectronic interconnects. The thermal signals were produced by applying a current through aluminum resistors deposited on soda-lime-silica glass, and the resulting refractive index changes were measured using a Mach-Zehnder interferometer with a microscope objective and high-speed camera. The temperatures of the resistors were measured both by the phase-retrieval method and by monitoring the resistance of the aluminum lines. The method used to analyze the phase is at least 60× faster than the state of the art but it maintains a small spatial phase noise of 16 nm, remaining comparable to the state of the art. For slowly varying signals, the system is able to perform absolute phase measurements over time, distinguishing temperature changes as small as 2 K. With angular scanning or structured illumination improvements, the system could also perform fast thermal tomography.

  13. Rapidly Activated Dynamic Phase Transitions in Nonlinear Solids

    Science.gov (United States)

    1993-02-15

    I Form Approv# edAD -A263 601 AiENTA11ON PAGE- f____________18 1. AGENCY USE ONLY (Lea"e blaWk 12. REPORT DATE 13. REPORT TYPE AND OATES COVEREO Feb...phase transforming media during high energy impact. Conversion of mechanical energy to thermal ener- gy has been studied by means of an extended theory...and Phase Structures in General Media , R. Fosdick, E. Dunn & M. Slemrod eds., IMA volume series, Springer- Verlag. Song, J. and T. L. Pence (1992

  14. Kinetics of the B1-B2 phase transition in KCl under rapid compression

    Science.gov (United States)

    Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Park, Changyong; Kono, Yoshio; Kenney-Benson, Curtis; Rod, Eric; Shen, Guoyin

    2016-01-01

    Kinetics of the B1-B2 phase transition in KCl has been investigated under various compression rates (0.03-13.5 GPa/s) in a dynamic diamond anvil cell using time-resolved x-ray diffraction and fast imaging. Our experimental data show that the volume fraction across the transition generally gives sigmoidal curves as a function of pressure during rapid compression. Based upon classical nucleation and growth theories (Johnson-Mehl-Avrami-Kolmogorov theories), we propose a model that is applicable for studying kinetics for the compression rates studied. The fit of the experimental volume fraction as a function of pressure provides information on effective activation energy and average activation volume at a given compression rate. The resulting parameters are successfully used for interpreting several experimental observables that are compression-rate dependent, such as the transition time, grain size, and over-pressurization. The effective activation energy (Qeff) is found to decrease linearly with the logarithm of compression rate. When Qeff is applied to the Arrhenius equation, this relationship can be used to interpret the experimentally observed linear relationship between the logarithm of the transition time and logarithm of the compression rates. The decrease of Qeff with increasing compression rate results in the decrease of the nucleation rate, which is qualitatively in agreement with the observed change of the grain size with compression rate. The observed over-pressurization is also well explained by the model when an exponential relationship between the average activation volume and the compression rate is assumed.

  15. A rare large right atrial myxoma with rapid growth rate.

    Science.gov (United States)

    Kelly, Shawn C; Steffen, Kelly; Stys, Adam T

    2014-10-01

    Atrial myxomas are the most common benign intracavitary cardiac neoplasms. They most frequently occur in the left atrium. Right atrial tumors are rare, comprising 20 percent of myxomas achieving an incidence of 0.02 percent. Due to their rarity, right atrial tumor development and associated clinical symptoms has not been well described. The classical clinical triad for the presentation of left atrial myxomas--heart failure, embolic events, and constitutional symptoms--may not be applicable to right sided tumors. Also, natural development of myxoma is not well described, as surgical resection is the common practice. Previously ascribed growth rates of myxomas refer mostly to left atrial ones, as right atrial tumors are rare. We present a case of right atrial myxoma with growth rates exceeding those previously described.

  16. Kinetic Phase Diagrams of Ternary Al-Cu-Li System during Rapid Solidification: A Phase-Field Study.

    Science.gov (United States)

    Yang, Xiong; Zhang, Lijun; Sobolev, Sergey; Du, Yong

    2018-02-08

    Kinetic phase diagrams in technical alloys at different solidification velocities during rapid solidification are of great importance for guiding the novel alloy preparation, but are usually absent due to extreme difficulty in performing experimental measurements. In this paper, a phase-field model with finite interface dissipation was employed to construct kinetic phase diagrams in the ternary Al-Cu-Li system for the first time. The time-elimination relaxation scheme was utilized. The solute trapping phenomenon during rapid solidification could be nicely described by the phase-field simulation, and the results obtained from the experiment measurement and/or the theoretical model were also well reproduced. Based on the predicted kinetic phase diagrams, it was found that with the increase of interface moving velocity and/or temperature, the gap between the liquidus and solidus gradually reduces, which illustrates the effect of solute trapping and tendency of diffusionless solidification.

  17. Heterogeneous phase fibrinolysis rates by damped oscillation rheometry.

    Science.gov (United States)

    Lee, Jae-Suk; Kaibara, Makoto; O'Rear, Edgar A

    2016-07-29

    Devices gauging viscoelastic properties of blood during coagulation like the thromboelastograph support fundamental research as well as point of care needs. Associated fibrinolysis data are based on endogenous species or plasminogen activator added to a homogeneous sample prior to clot formation. Digestion in a monolithic structure differs from the physical situation of thrombolytic therapy where surface reactions dominate. This study aims to develop rheological testing for heterogeneous phase fibrinolysis. Fibrinolysis rates were determined by phase change of a solid clot induced by autologous plasma/streptokinase (SK) in a rheometer sensitive to viscous damping. Initial slope or overall change in the logarithmic damping factor indicated fibrinolytic rates. Rates depended on clot geometry, phase volumes, clot composition and SK concentration. The damped oscillation rheometer can be adapted to determine relative rates of heterogeneous fibrinolysis in vitro.

  18. The rapid enrollment design for Phase I clinical trials.

    Science.gov (United States)

    Ivanova, Anastasia; Wang, Yunfei; Foster, Matthew C

    2016-07-10

    We propose a dose-finding design for Phase I oncology trials where each new patient is assigned to the dose most likely to be the target dose given observed data. The main model assumption is that the dose-toxicity curve is non-decreasing. This method is beneficial when it is desirable to assign a patient to a dose as soon as the patient is enrolled into a study. To prevent assignments to doses with limited toxicity information in fast accruing trials we propose a conservative rule that assigns temporary fractional toxicities to patients still in follow-up. We also recommend always using a safety rule in any fast accruing dose-finding trial. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Procedural Modeling for Rapid-Prototyping of Multiple Building Phases

    Science.gov (United States)

    Saldana, M.; Johanson, C.

    2013-02-01

    RomeLab is a multidisciplinary working group at UCLA that uses the city of Rome as a laboratory for the exploration of research approaches and dissemination practices centered on the intersection of space and time in antiquity. In this paper we present a multiplatform workflow for the rapid-prototyping of historical cityscapes through the use of geographic information systems, procedural modeling, and interactive game development. Our workflow begins by aggregating archaeological data in a GIS database. Next, 3D building models are generated from the ArcMap shapefiles in Esri CityEngine using procedural modeling techniques. A GIS-based terrain model is also adjusted in CityEngine to fit the building elevations. Finally, the terrain and city models are combined in Unity, a game engine which we used to produce web-based interactive environments which are linked to the GIS data using keyhole markup language (KML). The goal of our workflow is to demonstrate that knowledge generated within a first-person virtual world experience can inform the evaluation of data derived from textual and archaeological sources, and vice versa.

  20. Rapid Enhancement in General Relativistic Precession Rates due to Kozai Mechanism in Solar System Bodies

    Science.gov (United States)

    Sekhar, Aswin; Asher, David; Morbidelli, Alessandro; Werner, Stephanie; Vaubaillon, Jeremie; Li, Gongjie

    2017-06-01

    Two well known phenomena in orbital dynamics associated with low perihelion distance bodies are general relativistic (GR) precession and Lidov-Kozai (LK) oscillations.In this work, we are interested to identify bodies evolving in the near future (i.e. thousands of years in this case) into rapid sungrazing and sun colliding phases and undergoing inclination flips, due to LK like oscillations and being GR active at the same time. We find that LK mechanism leads to secular lowering of perihelion distance which in turn leads to a huge increase in GR precession of the argument of pericentre depending on the initial orbital elements. This in turn gives feedback to the LK mechanism as the eccentricity, inclination and argument of pericentre in Kozai cycles are closely correlated. In this work, we find real examples of solar system bodies which show rapid enhancement in GR precession rates due to LK like oscillations and there are cases where GR precession rate peaks to about 60 times that of the GR precession of Mercury thus showing the strength and complementary nature between these two dynamical phenomena.An analytical treatment is done on few bodies to understand the difference in their orbital evolution in the context of LK mechanism with and without GR precession term by incorporating suitable Hamiltonian dynamics. This result is subsequently matched using numerical integrations to find direct correlations. Real solar system bodies showing both GR precession and LK like oscillations are identified using compiled observational records from IAU-Minor Planet Center, Cometary Catalogue, IAU-Meteor Data Center and performing analytical plus numerical tests on them. This intermediate state (where GR and LK effects are comparable and co-exist) brings up the interesting possibility of drastic changes in GR precession rates during orbital evolution due to sungrazing and sun colliding phases induced by the LK like mechanism, thus combining both these important effects in a

  1. The influence of solidification rate on solute redistribution and second-phase formation in stainless steel alloys

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, J.W. (Lawrence Livermore National Lab., CA (USA)); Eagar, T.W.; Allen, S.M. (Massachusetts Inst. of Tech., Cambridge, MA (USA))

    1990-05-30

    Many common SS alloy microstructures consist of a mixture of ferrite and austenite phases, however, when these alloys are rapidly resolidified using laser beam (LB) or electron beam (EB) processes, they solidify in the single-phase-austenite or single-phase-ferrite mode. This paper investigates the influence of solidification rate on the reduction, and eventual elimination, of second phases during the rapid solidification of Fe-Ni-Cr alloys. The influence of solidification rate on the ferrite content of these alloys was studied by calculating the dendrite-tip undercooling and then incorporating these results into a solute-redistribution model. The calculations and experiments agree semi-quantitatively, allowing the relative fractions of primary and secondary phases that solidify from the melt to be calculated for a wide range of solidification rates. 7 refs., 1 fig.

  2. Possibility for rapid generation of high-pressure phases in single-crystal silicon by fast nanoindentation

    Science.gov (United States)

    Huang, Hu; Yan, Jiwang

    2015-11-01

    High-pressure phases of silicon such as Si-XII/Si-III exhibit attractive optical, electrical and chemical properties, but until now, it has been technologically impossible to produce a significant quantity of Si-XII or Si-III. In this study, to explore the possibility of generating high-pressure silicon phases efficiently, comparative nanoindentation experiments were conducted. Effects of the loading rate, unloading rate and maximum indentation load were investigated, and key factors affecting the high-pressure phase formation were identified. A new nanoindentation protocol is proposed that introduces an intermediate holding stage into the unloading process. The resulting end phases under the indent were detected by a laser micro-Raman spectrometer and compared with those formed in conventional nanoindentation. The results indicate that high-pressure phases Si-XII and Si-III were successfully formed during the intermediate holding stage even with a very high loading/unloading rate. This finding demonstrates the possibility of rapid production of high-pressure phases of silicon through fast mechanical loading and unloading.

  3. Disorder trapping by rapidly moving phase interface in an undercooled liquid

    Science.gov (United States)

    Galenko, Peter; Danilov, Denis; Nizovtseva, Irina; Reuther, Klemens; Rettenmayr, Markus

    2017-08-01

    Non-equilibrium phenomena such as the disappearance of solute drag, the origin of solute trapping and evolution of disorder trapping occur during fast transformations with originating metastable phases [D.M. Herlach, P.K. Galenko, D. Holland-Moritz, Metastable solids from undrercooled melts (Elsevier, Amsterdam, 2007)]. In the present work, a theoretical investigation of disorder trapping by a rapidly moving phase interface is presented. Using a model of fast phase transformations, a system of governing equations for the diffusion of atoms, and the evolution of both long-range order parameter and phase field variable is formulated. First numerical solutions are carried out for a congruently melting binary alloy system.

  4. Combination of Cooling Curve and Micro-Chemical Phase Analysis of Rapidly Quenched Magnesium AM60B Alloy

    Science.gov (United States)

    Marchwica, P. C.; Gesing, A. J.; Sokolowski, J. H.; Blawert, C.; Jekl, J.; Berkmortel, R.

    Macro test samples of magnesium alloy AM60B were melted and quenched at maximum instantaneous cooling rates ranging from -5°C/s to -500°C/s and the resultant cooling curves were analyzed. Characteristic reactions on these curves corresponding to formation of individual phases were identified with the aid of literature data as well as metallographic and micro-chemical analysis. The results indicate that these phases, their size and location in the micro structure, their chemistry and their relative proportions all change in response to the increase in the cooling rate. These rapid cooling rates are typical of real industrial solidification processes such as die casting. These findings can be used to improve future computer models of casting solidification processes for magnesium and for other alloys.

  5. A low cost rapid prototype platform for a three phase PFC rectifier application

    DEFF Research Database (Denmark)

    Haase, Frerk; Kouchaki, Alireza; Nymand, Morten

    2015-01-01

    In this paper the design and development of a low cost rapid prototype platform for a Three Phase PFC rectifier application is presented. The active rectifier consists of a SiC-MOSFET based PWM converter and a low cost rapid prototype platform for simulating and implementing the digital control...... is then performed using automatic code generation for embedded targets, which provided a close link between simulation and implementation of the PFC controller. The paper shows how this rapid prototype platform developed and how it was used for the design and implementation of the controller for a high efficient Si...

  6. Rapid Prediction of Configuration Aerodynamics in the ConceptualDesign Phase

    Directory of Open Access Journals (Sweden)

    C. Munro

    2001-01-01

    Full Text Available Conceptual aircraft design is characterised by the requirement to analyse a large number of configurations rapidly and cost effectively. For unusual configurations such as those typified by unmanned combat air vehicles (UCAVs adequately predicting their aerodynamic characteristics through existing empirical methods is fraught with uncertainty. By utilising rapid and low cost experimental tools such as the water tunnel and subscale flight testing it is proposed that the required aerodynamic characteristics can rapidly be acquired with sufficient fidelity for the conceptual design phase. Furthermore, the initial design predictions can to some extent be validated using flight-derived aerodynamic data from subscale flight testing.

  7. Impact of receiver and constellation on high rate GNSS phase rate measurements to monitor ionospheric irregularities

    Science.gov (United States)

    Ghoddousi-Fard, Reza

    2017-11-01

    High rate (1 Hz) GPS and GLONASS phase rate measurements from the global Real Time International GNSS Service (RT-IGS) network are used to monitor ionospheric irregularities. In this paper, impact of different receiver types and satellite constellations on GNSS-derived indices are studied. Constellation dependent background phase noise is quantified at RT-IGS stations for different receiver categories. Improved sampling of the ionosphere is achieved using multiple constellations. Correlation of hourly mean values of dual constellation GNSS indices with hourly magnetic ranges at a co-located auroral magnetic observatory slightly increased compared to when single constellation is used.

  8. Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A

    Directory of Open Access Journals (Sweden)

    Lev B. Leinson

    2015-02-01

    Full Text Available In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.

  9. Rapid Mantle Ascent Rates Beneath Brazil: Diamond Bullets from a Smoking Plume?

    Science.gov (United States)

    Walter, M. J.; Frost, D. J.

    2010-12-01

    The concept of upwelling plumes of mantle material is, for many, integral to plate tectonics theory. However, proving that plumes exist has been frustrating, and a growing cadre of geoscientists either deny their existence, or remain uncomfortably agnostic. To the uninitiated, seismic tomography can seem a game of now-you-see-it, now-you-don’t, and igneous petrology a malarial fever of now-it's-hot, now-it's-cold. We suggest that diamonds and their mineral inclusions from Juina, Brazil, may provide direct evidence for rapid mantle ascent caused by an upwelling plume. Cretaceous kimberlites in Juina are famous for producing diamonds with inclusions that originated at transition zone and lower mantle depths [1]. Many of these sublithospheric inclusions show evidence of un-mixing of original single-phase minerals into composite inclusions during ascent in the mantle unrelated to kimberlite eruption [2,3]. What is not known is the timeframe or causality of mantle ascent. Diamonds are notoriously hard to date, but Re/Os dates of sulfide inclusions in lithospheric diamonds are generally Early Proterozoic or older, whereas host kimberlites are typically much younger [4]. If the Brazilian diamonds were also ancient, then un-mixing could have been the result of a couple billion years of passive upward migration in the mantle, unrelated to anything so torrid as a mantle plume. Diamond J1 from the Collier4 kimberlite has a composite CaTiO3+CaSiO3 inclusion in a core growth zone (originally perovskite) and a majoritic garnet inclusion in a rim zone. On the basis of excess silica in its formula, the garnet crystallized at 6-7 GPa (about 200 km), consistent with the un-mixing pressure obtained from the perovskite [5]. Experimental phase relations show that the original single-phase perovskite must have formed deeper, between about 300 and 700 km [5]. Thus, diamond J1 exhibits polybaric growth, having ascended some 100 to 500 km during its growth history. Many other mineral

  10. Rapid and stable measurement of respiratory rate from Doppler radar signals using time domain autocorrelation model.

    Science.gov (United States)

    Sun, Guanghao; Matsui, Takemi

    2015-01-01

    Noncontact measurement of respiratory rate using Doppler radar will play a vital role in future clinical practice. Doppler radar remotely monitors the tiny chest wall movements induced by respiration activity. The most competitive advantage of this technique is to allow users fully unconstrained with no biological electrode attachments. However, the Doppler radar, unlike other contact-type sensors, is easily affected by the random body movements. In this paper, we proposed a time domain autocorrelation model to process the radar signals for rapid and stable estimation of the respiratory rate. We tested the autocorrelation model on 8 subjects in laboratory, and compared the respiratory rates detected by noncontact radar with reference contact-type respiratory effort belt. Autocorrelation model showed the effects of reducing the random body movement noise added to Doppler radar's respiration signals. Moreover, the respiratory rate can be rapidly calculated from the first main peak in the autocorrelation waveform within 10 s.

  11. Determination of rapid chlorination rate constants by a stopped-flow spectrophotometric competition kinetics method.

    Science.gov (United States)

    Song, Dean; Liu, Huijuan; Qiang, Zhimin; Qu, Jiuhui

    2014-05-15

    Free chlorine is extensively used for water and wastewater disinfection nowadays. However, it still remains a big challenge to determine the rate constants of rapid chlorination reactions although competition kinetics and stopped-flow spectrophotometric (SFS) methods have been employed individually to investigate fast reaction kinetics. In this work, we proposed an SFS competition kinetics method to determine the rapid chlorination rate constants by using a common colorimetric reagent, N,N-diethyl-p-phenylenediamine (DPD), as a reference probe. A kinetic equation was first derived to estimate the reaction rate constant of DPD towards chlorine under a given pH and temperature condition. Then, on that basis, an SFS competition kinetics method was proposed to determine directly the chlorination rate constants of several representative compounds including tetracycline, ammonia, and four α-amino acids. Although Cl2O is more reactive than HOCl, its contribution to the overall chlorination kinetics of the test compounds could be neglected in this study. Finally, the developed method was validated through comparing the experimentally measured chlorination rate constants of the selected compounds with those obtained or calculated from literature and analyzing with Taft's correlation as well. This study demonstrates that the SFS competition kinetics method can measure the chlorination rate constants of a test compound rapidly and accurately. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Strain rate behaviour of multi-phase and complex-phase steels for automotive applications

    Directory of Open Access Journals (Sweden)

    Singha M.K.

    2012-08-01

    Full Text Available A combined study on the mechanical behaviour of multi-phase 800 high yield strength steel (MP800HY and complex-phase 800 steel (CP800 is carried out under tensile loads in the strain rate range from 0.001s−1 to 750s−1. Quasi-static (0.001s−1 tests are performed on electromechanical machine, whereas, medium (5s−1 and 25s−1 and high strain rate (250s−1, 500s−1 and 750s−1 experiments are conducted on hydro-pneumatic machine (HPM and modified Hopkinson bar (MHB setup respectively. The thermal softening behaviors of the materials are investigated at quasi-static condition and the materials’ m-parameters of the existing Johnson-Cook model are imposed in authors’ previous work. Thereafter, the predicted flow stress by Johnson-Cook model has been compared with the experimental results.

  13. Enhancement of Lipase Enzyme Activity in Non-Aqueous Media through a Rapid Three Phase Partitioning and Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    N. Saifuddin

    2008-01-01

    Full Text Available Three phase partitioning is fast developing as a novel bio-separation strategy with a wide range of applications including enzyme stability and enhancement of its catalytic activity. pH tuning of enzyme is now well known for use in non-aqueous systems. Tuned enzyme was prepared using a rapid drying technique of microwave dehydration (time required around 15 minutes. Further enhancement was achieved by three phase partitioning (TPP method. With optimal condition of ammonium sulphate and t-butanol, the protein appeared as an interfacial precipitate between upper t-butanol and lower aqueous phases. In this study we report the results on the lipase which has been subjected to pH tuning and TPP, which clearly indicate the remarkable increase in the initial rate of transesterification by 3.8 times. Microwave irradiation was found to increase the initial reaction rates by further 1.6 times, hence giving a combined increase in activity of about 5.4 times. Hence it is shown that microwave irradiation can be used in conjunction with other strategies (like pH tuning and TPP for enhancing initial reaction rates.

  14. Early-phase transmission of Yersinia pestis by unblocked fleas as a mechanism explaining rapidly spreading plague epizootics.

    Science.gov (United States)

    Eisen, Rebecca J; Bearden, Scott W; Wilder, Aryn P; Montenieri, John A; Antolin, Michael F; Gage, Kenneth L

    2006-10-17

    Plague is a highly virulent disease believed to have killed millions during three historic human pandemics. Worldwide, it remains a threat to humans and is a potential agent of bioterrorism. Dissemination of Yersinia pestis, the etiological agent of plague, by blocked fleas has been the accepted paradigm for flea-borne transmission. However, this mechanism, which requires a lengthy extrinsic incubation period before a short infectious window often followed by death of the flea, cannot sufficiently explain the rapid rate of spread that typifies plague epidemics and epizootics. Inconsistencies between the expected rate of spread by blocked rat fleas and that observed during the Black Death has even caused speculation that plague was not the cause of this medieval pandemic. We used the primary vector to humans in North America, Oropsylla montana, which rarely becomes blocked, as a model for studying alternative flea-borne transmission mechanisms. Our data revealed that, in contrast to the classical blocked flea model, O. montana is immediately infectious, transmits efficiently for at least 4 d postinfection (early phase) and may remain infectious for a long time because the fleas do not suffer block-induced mortality. These factors match the criteria required to drive plague epizootics as defined by recently published mathematical models. The scenario of efficient early-phase transmission by unblocked fleas described in our study calls for a paradigm shift in concepts of how Y. pestis is transmitted during rapidly spreading epizootics and epidemics, including, perhaps, the Black Death.

  15. Insight into the Physical and Dynamical Processes that Control Rapid Increases in Total Flash Rate

    Science.gov (United States)

    Schultz, Christopher J.; Carey, Lawrence D.; Schultz, Elise V.; Blakeslee, Richard J.; Goodman, Steven J.

    2015-01-01

    Rapid increases in total lightning (also termed "lightning jumps") have been observed for many decades. Lightning jumps have been well correlated to severe and hazardous weather occurrence. The main focus of lightning jump work has been on the development of lightning algorithms to be used in real-time assessment of storm intensity. However, in these studies it is typically assumed that the updraft "increases" without direct measurements of the vertical motion, or specification of which updraft characteristic actually increases (e.g., average speed, maximum speed, or convective updraft volume). Therefore, an end-to-end physical and dynamical basis for coupling rapid increases in total flash rate to increases in updraft speed and volume must be understood in order to ultimately relate lightning occurrence to severe storm metrics. Herein, we use polarimetric, multi-Doppler, and lightning mapping array measurements to provide physical context as to why rapid increases in total lightning are closely tied to severe and hazardous weather.

  16. Video-rate processing in tomographic phase microscopy of biological cells using CUDA.

    Science.gov (United States)

    Dardikman, Gili; Habaza, Mor; Waller, Laura; Shaked, Natan T

    2016-05-30

    We suggest a new implementation for rapid reconstruction of three-dimensional (3-D) refractive index (RI) maps of biological cells acquired by tomographic phase microscopy (TPM). The TPM computational reconstruction process is extremely time consuming, making the analysis of large data sets unreasonably slow and the real-time 3-D visualization of the results impossible. Our implementation uses new phase extraction, phase unwrapping and Fourier slice algorithms, suitable for efficient CPU or GPU implementations. The experimental setup includes an external off-axis interferometric module connected to an inverted microscope illuminated coherently. We used single cell rotation by micro-manipulation to obtain interferometric projections from 73 viewing angles over a 180° angular range. Our parallel algorithms were implemented using Nvidia's CUDA C platform, running on Nvidia's Tesla K20c GPU. This implementation yields, for the first time to our knowledge, a 3-D reconstruction rate higher than video rate of 25 frames per second for 256 × 256-pixel interferograms with 73 different projection angles (64 × 64 × 64 output). This allows us to calculate additional cellular parameters, while still processing faster than video rate. This technique is expected to find uses for real-time 3-D cell visualization and processing, while yielding fast feedback for medical diagnosis and cell sorting.

  17. Rapid rates of soil production in the western Southern Alps, New Zealand

    Science.gov (United States)

    Larsen, I. J.; Almond, P. C.; Eger, A.; Stone, J. O.; Malcolm, B.; Montgomery, D. R.

    2012-12-01

    Quantifying rates of soil production is necessary for determining the relative magnitude of the processes that drive the evolution of mountain topography and for assessing proposed links among tectonic uplift, erosion, weathering, and global biogeochemical cycles. However, little is known about the role soil production plays in the denudation of rapidly uplifting mountains. We addressed this problem by sampling soil and river sediment from five catchments in the rapidly uplifting and high rainfall portion of the western Southern Alps, New Zealand. Soils were sampled from ridgetops with subalpine forest and dense alpine shrubland vegetation. Results from 11 measurements of in situ-produced 10Be in soils from three catchments show that rock is rapidly converted to soil, with the highest measured rate approaching 2 mm yr-1. Soil production rates at two of the ridgetops decline exponentially as soil depth increases, consistent with previously proposed soil production functions. The third site exhibits an ambiguous soil production rate-depth relationship. The y-intercepts, or maximum predicted soil production rate where the soil depth is equal to zero, at the sites with well-defined soil production functions are 7-9 times greater than those in other tectonically-active mountains and 1-2 orders of magnitude greater than values from drier and more tectonically-quiescent landscapes, indicating that rock can be converted to soil at substantially higher rates than previously recognized. The maximum predicted soil production rate values are 1.5 to 2.5 times lower than watershed-scale denudation rates inferred from in situ 10Be concentrations in stream sediment, indicating that soil production rates approach, but do not reach catchment-averaged values, which also reflect denudation by bedrock landslides. Ongoing work on additional samples will lead to a refinement of the soil production functions and provide rates for two additional sites. In-progress measurement of zirconium

  18. Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point selection, however, requires a model for solute partitioning under a given set of growth conditions. Therefore, analytical solute trapping models which describe the chemical partitioning as a function of steady state interface velocities have been developed and widely utilized in most of the theoretical investigations of rapid solidification. However, these

  19. The impact of increased loading rate on granular media, rapid depth filtration of wastewater.

    Science.gov (United States)

    Williams, Gordon J; Sheikh, Bahman; Holden, Robert B; Kouretas, Tom J; Nelson, Kara L

    2007-11-01

    The impact of loading rate on tertiary filtration of wastewater was studied using a pilot-scale, dual-media, rapid depth filtration system. Loading rates of 12.2, 15.3, 18.3, 21.4, and 24.4m/h were tested on parallel filter columns treating the same coagulated secondary wastewater to determine the impact on removal of turbidity, particles (2-15 microm), total coliform bacteria, Escherichia coli, and MS2 bacteriophage, as well as on the particle deposition profile in the filter bed. Increasing the loading rate from 12.2 to 24.4m/h decreased the removal efficiencies for all metrics. The observed impact of loading rate on particle removal was similar to that predicted by a clean-bed filtration model, although the model significantly underestimated the removal efficiencies of the smaller particles. For two loading rates, 12.2 and 18.3m/h, the effect of coagulant dose was also studied; the negative impact of loading rate on removal efficiency was eliminated by increasing the coagulant dose for the higher loading rate, which also resulted in removal of particles deeper in the filter bed. For all conditions studied, loading rate had no observable impact on the ability to disinfect filter effluents with chloramines. The results of this research indicate that loading rates higher than those typically used in tertiary filtration can produce acceptable effluent quality, and support a regulatory approach based on filter effluent turbidity.

  20. Rapid Single-step Formation of Liposomes by Flow Assisted Stationary Phase Interdiffusion.

    Science.gov (United States)

    Has, Chandra; Phapal, Sopan M; Sunthar, P

    2018-01-17

    Laboratory preparation of unilamellar liposomes often involves multiple steps carried out over several hours to achieve a monodisperse size distribution. Here we present a methodology, based on a recently introduced lipid self-assembly principle-stationary phase interdiffusion (SPI)-to prepare large unilamellar vesicles (LUVs) of a monodisperse population in a short period of about 10min. The stationary interface between a lipid-ethanol phase and an aqueous phase is created by a density difference induced convective flow in a horizontal capillary. The average size of the liposomes, as expected from the SPI principle, is modulated only by the temperature and the type of lipids. Lipid concentration, ethanol content, pH of the aqueous phase, and the time duration of the experiment have little influence on the mean diameter of the vesicles. This simple methodology can be easily carried out with a capillary and a micro-needled syringe, and provides a rapid production tool for researchers requiring reproducible liposome suspensions. Refined natural lipids, based on soy and egg lecithin mixtures, yield LUVs in the range 100-200 nm, suitable for drug delivery applications. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Controlled precipitation for enhanced dissolution rate of flurbiprofen: development of rapidly disintegrating tablets.

    Science.gov (United States)

    Essa, Ebtessam A; Elmarakby, Amira O; Donia, Ahmed M A; El Maghraby, Gamal M

    2017-09-01

    The aim of this work was to investigate the potential of controlled precipitation of flurbiprofen on solid surface, in the presence or absence of hydrophilic polymers, as a tool for enhanced dissolution rate of the drug. The work was extended to develop rapidly disintegrated tablets. This strategy provides simple technique for dissolution enhancement of slowly dissolving drugs with high scaling up potential. Aerosil was dispersed in ethanolic solution of flurbiprofen in the presence and absence of hydrophilic polymers. Acidified water was added as antisolvent to produce controlled precipitation. The resultant particles were centrifuged and dried at ambient temperature before monitoring the dissolution pattern. The particles were also subjected to FTIR spectroscopic, X-ray diffraction and thermal analyses. The FTIR spectroscopy excluded any interaction between flurbiprofen and excipients. The thermal analysis reflected possible change in the crystalline structure and or crystal size of the drug after controlled precipitation in the presence of hydrophilic polymers. This was further confirmed by X-ray diffraction. The modulation in the crystalline structure and size was associated with a significant enhancement in the dissolution rate of flurbiprofen. Optimum formulations were successfully formulated as rapidly disintegrating tablet with subsequent fast dissolution. Precipitation on a large solid surface area is a promising strategy for enhanced dissolution rate with the presence of hydrophilic polymers during precipitation process improving the efficiency.

  2. Rapid startup and high rate nitrogen removal from anaerobic sludge digester liquor using a SNAP process.

    Science.gov (United States)

    Qiao, Sen; Nishiyama, Takashi; Fujii, Tatsuo; Bhatti, Zafar; Furukawa, Kenji

    2012-02-01

    In this study, a single-stage autotrophic nitrogen removal reactor, packed with a novel acrylic fiber biomass carrier material (Biofix), was applied for nitrogen removal from sludge digester liquor. For rapid start-up, conventional activated sludge was added to the reactor soon after the attachment of anammox biomass on the Biofix carriers, which allowed conventional activated sludge to form a protective layer of biofilm around the anammox biomass. The Nitrogen removal efficiency reached 75% within 1 week at a nitrogen loading rate of 0.46 kg-N/m(3)/day for synthetic wastewater treatment. By the end of the synthetic wastewater treatment period, the maximum nitrogen removal rate had increased to 0.92 kg-N/m(3)/day at a nitrogen loading rate of 1.0 kg-N/m(3)/day. High nitrogen removal rate was also achieved during the actual raw digester liquor treatment with the highest nitrogen removal rate being 0.83 kg-N/m(3)/day at a nitrogen loading rate of 0.93 kg-N/m(3)/day. The thick biofilm on Biofix carriers allowed anammox bacteria to survive under high DO concentration of 5-6 mg/l resulting in stable and high nitrogen removal performance. FISH and CLSM analysis demonstrated that anammox bacteria coexisted and surrounded by ammonium oxidizing bacteria.

  3. Perceptual processing of natural scenes at rapid rates: effects of complexity, content, and emotional arousal.

    Science.gov (United States)

    Löw, Andreas; Bradley, Margaret M; Lang, Peter J

    2013-12-01

    During rapid serial visual presentation (RSVP), the perceptual system is confronted with a rapidly changing array of sensory information demanding resolution. At rapid rates of presentation, previous studies have found an early (e.g., 150-280 ms) negativity over occipital sensors that is enhanced when emotional, as compared with neutral, pictures are viewed, suggesting facilitated perception. In the present study, we explored how picture composition and the presence of people in the image affect perceptual processing of pictures of natural scenes. Using RSVP, pictures that differed in perceptual composition (figure-ground or scenes), content (presence of people or not), and emotional content (emotionally arousing or neutral) were presented in a continuous stream for 330 ms each with no intertrial interval. In both subject and picture analyses, all three variables affected the amplitude of occipital negativity, with the greatest enhancement for figure-ground compositions (as compared with scenes), irrespective of content and emotional arousal, supporting an interpretation that ease of perceptual processing is associated with enhanced occipital negativity. Viewing emotional pictures prompted enhanced negativity only for pictures that depicted people, suggesting that specific features of emotionally arousing images are associated with facilitated perceptual processing, rather than all emotional content.

  4. Rapid RNA Exchange in Aqueous Two-Phase System and Coacervate Droplets

    Science.gov (United States)

    Jia, Tony Z.; Hentrich, Christian; Szostak, Jack W.

    2014-02-01

    Compartmentalization in a prebiotic setting is an important aspect of early cell formation and is crucial for the development of an artificial protocell system that effectively couples genotype and phenotype. Aqueous two-phase systems (ATPSs) and complex coacervates are phase separation phenomena that lead to the selective partitioning of biomolecules and have recently been proposed as membrane-free protocell models. We show in this study through fluorescence recovery after photobleaching (FRAP) microscopy that despite the ability of such systems to effectively concentrate RNA, there is a high rate of RNA exchange between phases in dextran/polyethylene glycol ATPS and ATP/poly-L-lysine coacervate droplets. In contrast to fatty acid vesicles, these systems would not allow effective segregation and consequent evolution of RNA, thus rendering these systems ineffective as model protocells.

  5. Rapid analysis of constituents of Radix Cyathulae using hydrophilic interaction-reverse phase LC-MS.

    Science.gov (United States)

    Ren, Mei-Ting; Li, Hui-Jun; Sheng, Long-Sheng; Liu, Peng; Li, Ping

    2009-11-01

    A hydrophilic interaction chromatography (HILIC) and reverse-phase liquid chromatography (RPLC) coupled with electrospray TOF MS method was developed for the analysis and characterization of constituents in the radix of Cyathula officinalis Kuan. Separation parameters of HILIC such as buffer pH, mobile phase strength, and organic modifier were evaluated. Fructose, glucose, and sucrose were identified by HILIC-ESI/TOF MS. Reverse-phase liquid chromatography-ESI/TOF MS were applied for quick and sensitive identification of major saponins in Cyathula officinalis. In-source collision-induced dissociation has been performed to elucidate the fragmentation pathways of oleanane-, hederagenin-, and gypsogmin-type saponins. Twelve saponins were characterized in this plant for the first time, and four of them were presumed to be new compounds. In addition, one phytoecdysteroid (cyasterone) and one coumarin (6,7-dimethoxycoumarin) were detected at the same time. The present method was capable of rapid characterizing and providing structure information of constituents from herbal drugs.

  6. Plastid Phylogenomics Resolve Deep Relationships among Eupolypod II Ferns with Rapid Radiation and Rate Heterogeneity.

    Science.gov (United States)

    Wei, Ran; Yan, Yue-Hong; Harris, A J; Kang, Jong-Soo; Shen, Hui; Xiang, Qiao-Ping; Zhang, Xian-Chun

    2017-06-01

    The eupolypods II ferns represent a classic case of evolutionary radiation and, simultaneously, exhibit high substitution rate heterogeneity. These factors have been proposed to contribute to the contentious resolutions among clades within this fern group in multilocus phylogenetic studies. We investigated the deep phylogenetic relationships of eupolypod II ferns by sampling all major families and using 40 plastid genomes, or plastomes, of which 33 were newly sequenced with next-generation sequencing technology. We performed model-based analyses to evaluate the diversity of molecular evolutionary rates for these ferns. Our plastome data, with more than 26,000 informative characters, yielded good resolution for deep relationships within eupolypods II and unambiguously clarified the position of Rhachidosoraceae and the monophyly of Athyriaceae. Results of rate heterogeneity analysis revealed approximately 33 significant rate shifts in eupolypod II ferns, with the most heterogeneous rates (both accelerations and decelerations) occurring in two phylogenetically difficult lineages, that is, the Rhachidosoraceae-Aspleniaceae and Athyriaceae clades. These observations support the hypothesis that rate heterogeneity has previously constrained the deep phylogenetic resolution in eupolypods II. According to the plastome data, we propose that 14 chloroplast markers are particularly phylogenetically informative for eupolypods II both at the familial and generic levels. Our study demonstrates the power of a character-rich plastome data set and high-throughput sequencing for resolving the recalcitrant lineages, which have undergone rapid evolutionary radiation and dramatic changes in substitution rates. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  7. Digital image processing based mass flow rate measurement of gas/solid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Song Ding; Peng Lihui; Lu Geng; Yang Shiyuan [Tsinghua National Laboratory for Information Science and Technology, Department of Automation, Tsinghua University, Beijing, 100084 (China); Yan Yong, E-mail: lihuipeng@tsinghua.edu.c [University of Kent, Canterbury, Kent CT2 7NT (United Kingdom)

    2009-02-01

    With the rapid growth of the process industry, pneumatic conveying as a tool for the transportation of a wide variety of pulverized and granular materials has become widespread. In order to improve plant control and operational efficiency, it is essential to know the parameters of the particle flow. This paper presents a digital imaging based method which is capable of measuring multiple flow parameters, including volumetric concentration, velocity and mass flow rate of particles in the gas/solid two phase flow. The measurement system consists of a solid state laser for illumination, a low-cost CCD camera for particle image acquisition and a microcomputer with bespoke software for particle image processing. The measurements of particle velocity and volumetric concentration share the same sensing hardware but use different exposure time and different image processing methods. By controlling the exposure time of the camera a clear image and a motion blurred image are obtained respectively. The clear image is thresholded by OTSU method to identify the particles from the dark background so that the volumetric concentration is determined by calculating the ratio between the particle area and the total area. Particle velocity is derived from the motion blur length, which is estimated from the motion blurred images by using the travelling wave equation method. The mass flow rate of particles is calculated by combining the particle velocity and volumetric concentration. Simulation and experiment results indicate that the proposed method is promising for the measurement of multiple parameters of gas/solid two-phase flow.

  8. Lateralized effect of rapid-rate transcranial magnetic stimulation of the prefrontal cortex on mood.

    Science.gov (United States)

    Pascual-Leone, A; Catalá, M D; Pascual-Leone Pascual, A

    1996-02-01

    We studied the effects of rapid-rate transcranial magnetic stimulation (rTMS) of different scalp positions on mood. Ten normal volunteers rated themselves before and after rTMS on five analog scales labeled "Tristeza" (Sadness), "Ansiedad" (Anxiety), "Alegria" (Happiness), "Cansancio" (Tiredness), and "Dolor/Malestar" (Pain/Discomfort). rTMS was applied to the right lateral prefrontal, left prefrontal, or midline frontal cortex in trains of 5 seconds' duration at 10 Hz and 110% of the subject's motor threshold intensity. Each stimulation position received 10 trains separated by a 25-second pause. No clinically apparent mood changes were evoked by rTMS to any of the scalp positions in any subject. However, left prefrontal rTMS resulted in a significant increase in the Sadness ratings (Tristeza) and a significant decrease in the Happiness ratings ("Alegria") as compared with right prefrontal and midfrontal cortex stimulation. These results show differential effects of rTMS of left and right prefrontal cortex stimulation on mood and illustrate the lateralized control of mood in normal volunteers.

  9. A novel method for ATLAS FSI alignment based on rapid, direct phase monitoring

    CERN Document Server

    Gibson, S M; The ATLAS collaboration; Horton, K; Lewis, A; Liang, Z; Livermore, S; Mattravers, C; Nickerson, R B

    2010-01-01

    Frequency Scanning Interferometry is a precise, multiple distance measurement technique, originally developed for ATLAS, which is suited to a variety of applications in the survey and alignment of future accelerators and particle detectors. The ATLAS inner detector is instrumented with an automated FSI alignment system, capable of simultaneously measuring hundreds of interferometers within the operational particle tracker. The alignment system began data taking in 2008 and we present the latest results from the on-detector system during LHC running. A new method has been developed based on rapid, direct monitoring of the interferometer phase, which allows the measurement of short term motions with improved precision, at a fraction of the wavelength of light (typically sensitive to < 50 nm). We outline the theory behind this novel technique and demonstrate precise measurements from ATLAS, which reveal interesting micron-level movements of the inner detector, correlated with thermal cycles and magnetic f...

  10. Rapid experimental SAD phasing and hot-spot identification with halogenated fragments

    Directory of Open Access Journals (Sweden)

    Joseph D. Bauman

    2016-01-01

    Full Text Available Through X-ray crystallographic fragment screening, 4-bromopyrazole was discovered to be a `magic bullet' that is capable of binding at many of the ligand `hot spots' found in HIV-1 reverse transcriptase (RT. The binding locations can be in pockets that are `hidden' in the unliganded crystal form, allowing rapid identification of these sites for in silico screening. In addition to hot-spot identification, this ubiquitous yet specific binding provides an avenue for X-ray crystallographic phase determination, which can be a significant bottleneck in the determination of the structures of novel proteins. The anomalous signal from 4-bromopyrazole or 4-iodopyrazole was sufficient to determine the structures of three proteins (HIV-1 RT, influenza A endonuclease and proteinase K by single-wavelength anomalous dispersion (SAD from single crystals. Both compounds are inexpensive, readily available, safe and very soluble in DMSO or water, allowing efficient soaking into crystals.

  11. Multiplex Solid-Phase PCR for Rapid Detection and Identification of Salmonella spp. at Sub-species

    DEFF Research Database (Denmark)

    Cao, Cuong; Høgberg, Jonas; Wolff, Anders

    -PCR gel electrophoresis. The method will be useful for development of point-of-care devices for rapid detection and identification of Salmonella spp. A solid-phase PCR for rapid detection and identification of S. enteritidis, S. typhimurium and S. dublin is developed. The method offers advantages......This study presents a solid-phase PCR (SP-PCR) for rapid detection, identification, and sub-typing of various Salmonella species, the major food-borne cause of salmonellosis. The target DNA is firstly amplified with PCR primers (one primer is labeled with fluorophores) in the liquid phase...... by the liquid phase primer thus generating new templates for the SP-PCR. After the reaction, PCR products labeled with fluorophores remain attached to the substrate and can be visualized directly by fluorescence readout devices. Using this method, S. enteritidis, S. typhimurium and S. dublin can be detected...

  12. Rapidly tunable optical parametric oscillator based on aperiodic quasi-phase matching.

    Science.gov (United States)

    Descloux, Delphine; Dherbecourt, Jean-Baptiste; Melkonian, Jean-Michel; Raybaut, Myriam; Lai, Jui-Yu; Drag, Cyril; Godard, Antoine

    2016-05-16

    A new optical parametric oscillator (OPO) architecture with high tuning speed capability is demonstrated. This device exploits the versatility offered by aperiodic quasi-phase matching (QPM) to provide a broad parametric gain spectrum without changing the temperature, angle, or position of the nonlinear crystal. Rapid tuning is then straightforwardly achieved using a fast intracavity spectral filter. This concept is demonstrated here for a picosecond synchronously pumped OPO containing an aperiodically poled MgO-doped LiNbO3 crystal and a rapidly tunable spectral filter based on a diffraction grating. Tuning over 160 nm around 3.86 μm is achieved at fixed temperature and a fast tuning over 30 nm in 40 μs is demonstrated. Different configurations are tested and compared. The cavity length detuning is analyzed and discussed. This device is successfully used to detect N2O by absorption. This approach could be generalized to other spectral ranges (e.g., visible) and temporal regimes (e.g., continuous-wave or nanosecond).

  13. Rapid assessment of malaria transmission using age-specific sero-conversion rates.

    Directory of Open Access Journals (Sweden)

    Laveta Stewart

    2009-06-01

    Full Text Available Malaria transmission intensity is a crucial determinant of malarial disease burden and its measurement can help to define health priorities. Rapid, local estimates of transmission are required to focus resources better but current entomological and parasitological methods for estimating transmission intensity are limited in this respect. An alternative is determination of antimalarial antibody age-specific sero-prevalence to estimate sero-conversion rates (SCR, which have been shown to correlate with transmission intensity. This study evaluated SCR generated from samples collected from health facility attendees as a tool for a rapid assessment of malaria transmission intensity.The study was conducted in north east Tanzania. Antibodies to Plasmodium falciparum merozoite antigens MSP-1(19 and AMA-1 were measured by indirect ELISA. Age-specific antibody prevalence was analysed using a catalytic conversion model based on maximum likelihood to generate SCR. A pilot study, conducted near Moshi, found SCRs for AMA-1 were highly comparable between samples collected from individuals in a conventional cross-sectional survey and those collected from attendees at a local health facility. For the main study, 3885 individuals attending village health facilities in Korogwe and Same districts were recruited. Both malaria parasite prevalence and sero-positivity were higher in Korogwe than in Same. MSP-1(19 and AMA-1 SCR rates for Korogwe villages ranged from 0.03 to 0.06 and 0.07 to 0.21 respectively. In Same district there was evidence of a recent reduction in transmission, with SCR among those born since 1998 [MSP-1(19 0.002 to 0.008 and AMA-1 0.005 to 0.014 ] being 5 to 10 fold lower than among individuals born prior to 1998 [MSP-1(19 0.02 to 0.04 and AMA-1 0.04 to 0.13]. Current health facility specific estimates of SCR showed good correlations with malaria incidence rates in infants in a contemporaneous clinical trial (MSP-1(19 r(2 = 0.78, p<0.01 & AMA-1 r

  14. Three dimensional evaluation of alveolar bone changes in response to different rapid palatal expansion activation rates

    Directory of Open Access Journals (Sweden)

    Brian LaBlonde

    Full Text Available ABSTRACT Introduction: The aim of this multi-center retrospective study was to quantify the changes in alveolar bone height and thickness after using two different rapid palatal expansion (RPE activation protocols, and to determine whether a more rapid rate of expansion is likely to cause more adverse effects, such as alveolar tipping, dental tipping, fenestration and dehiscence of anchorage teeth. Methods: The sample consisted of pre- and post-expansion records from 40 subjects (age 8-15 years who underwent RPE using a 4-banded Hyrax appliance as part of their orthodontic treatment to correct posterior buccal crossbites. Subjects were divided into two groups according to their RPE activation rates (0.5 mm/day and 0.8 mm/day; n = 20 each group. Three-dimensional images for all included subjects were evaluated using Dolphin Imaging Software 11.7 Premium. Maxillary base width, buccal and palatal cortical bone thickness, alveolar bone height, and root angulation and length were measured. Significance of the changes in the measurements was evaluated using Wilcoxon signed-rank test and comparisons between groups were done using ANOVA. Significance was defined at p ≤ 0.05. Results: RPE activation rates of 0.5 mm per day (Group 1 and 0.8 mm per day (Group 2 caused significant increase in arch width following treatment; however, Group 2 showed greater increases compared to Group 1 (p < 0.01. Buccal alveolar height and width decreased significantly in both groups. Both treatment protocols resulted in significant increases in buccal-lingual angulation of teeth; however, Group 2 showed greater increases compared to Group 1 (p < 0.01. Conclusion: Both activation rates are associated with significant increase in intra-arch widths. However, 0.8 mm/day resulted in greater increases. The 0.8 mm/day activation rate also resulted in more increased dental tipping and decreased buccal alveolar bone thickness over 0.5 mm/day.

  15. Rapid solid-phase extraction and analysis of resveratrol and other polyphenols in red wine.

    Science.gov (United States)

    Hashim, Shima N N S; Schwarz, Lachlan J; Boysen, Reinhard I; Yang, Yuanzhong; Danylec, Basil; Hearn, Milton T W

    2013-10-25

    Red wine has long been credited as a good source of health-beneficial antioxidants, including the bioactive polyphenols catechin, quercetin, and (E)-resveratrol. In this paper, we report the application of reusable molecularly imprinted polymers (MIPs) for the selective and robust solid-phase extraction (SPE) and rapid analysis of (E)-resveratrol (LOD=8.87×10(-3) mg/L, LOQ=2.94×10(-2) mg/L), along with a range of other polyphenols from an Australian Pinot noir red wine. Optimization of the molecularly imprinted solid-phase extraction (MISPE) protocol resulted in the significant enrichment of (E)-resveratrol and several structurally related polyphenols. These secondary metabolites were subsequently identified by RP-HPLC and μLC-ESI ion trap MS/MS methods. The developed MISPE protocol employed low volumes of environmentally benign solvents selected according to the Green Chemistry principles, and resulted in the recovery of 99% of the total (E)-resveratrol present. These results further demonstrate the potential of generic protocols for the analysis of target compound with health beneficial properties within the food and nutraceutical industries using tailor-made MIPs. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Linguistic penetration at Schneider's Phase 4: Acceptability ratings ...

    African Journals Online (AJOL)

    Tolerance for features of BSAE in formal, academic writing suggests that a wider acceptance of BSAE is emerging. I argue that even a low level of acceptance of features of BSAE by this sample group can suggest linguistic convergence and initial entry into Phase 4 of Schneider's (2009) Dynamic Model of Postcolonial ...

  17. Noncontact phase-sensitive dynamic optical coherence elastography at megahertz rate

    Science.gov (United States)

    Singh, Manmohan; Wu, Chen; Liu, Chih-Hao; Li, Jiasong; Schill, Alexander; Nair, Achuth; Kistenev, Yury V.; Larin, Kirill V.

    2016-03-01

    Dynamic optical coherence elastography (OCE) techniques have shown great promise at quantitatively obtaining the biomechanical properties of tissue. However, the majority of these techniques have required multiple temporal OCT acquisitions (M-B mode) and corresponding excitations, which lead to clinically unfeasible acquisition times and potential tissue damage. Furthermore, the large data sets and extended laser exposures hinder their translation to the clinic, where patient discomfort and safety are critical criteria. In this work we demonstrate noncontact true kilohertz frame-rate dynamic optical coherence elastography by directly imaging a focused air-pulse induced elastic wave with a home-built phase-sensitive OCE system based on a 4X buffered Fourier Domain Mode Locked swept source laser with an A-scan rate of ~1.5 MHz. The elastic wave was imaged at a frame rate of ~7.3 kHz using only a single excitation. In contrast to previous techniques, successive B-scans were acquired over the measurement region (B-M mode) in this work. The feasibility of this method was validated by quantifying the elasticity of tissue-mimicking agar phantoms as well as porcine corneas ex vivo at different intraocular pressures. The results demonstrate that this method can acquire a depth-resolved elastogram in milliseconds. The reduced data set enabled a rapid elasticity assessment, and the ultra-fast acquisition speed allowed for a clinically safe laser exposure to the cornea.

  18. Cross-sectional study of possible association between rapid eating and high body fat rates among female Japanese college students.

    Science.gov (United States)

    Yaguchi-Tanaka, Yuri; Kawagoshi, Yumiko; Sasaki, Satoshi; Fukao, Akira

    2013-01-01

    The incidence of excessive body fat among young Japanese females with a normal BMI, which is referred to as normal weight obesity (NWO), has recently increased. Some studies have associated eating rates with BMI. However, an association between body fat rate and dietary habits has not been proven. We compared differences in dietary habits between 72 female Japanese junior college students with normal (Eating rapidly was significantly associated with body fat ratios. Our findings suggest that eating rapidly increases body fat ratios.

  19. Strain rate sensitivity analysis in phase-field dislocation dynamics

    OpenAIRE

    Cao, Lei; Koslowski, Marisol

    2014-01-01

    We present dislocation simulations involving the collective behavior of partials and extended full dislocations in nanocrystalline (nc) materials. Although atomistic simulations have shown the importance of including partial dislocations in high strain rate simulations, the behavior of partial dislocations in complex geometries with low strain rates has not been explored. To account for the dissociation of dislocations into partials we include the full representation of the gamma surface for ...

  20. Evaluation of Ti(3)Si Phase Stability from Heat-Treated, Rapidly Solidified Ti-Si Alloys

    OpenAIRE

    COSTA, Alex Matos da Silva; de Lima, Gisele Ferreira; Rodrigues,Geovani; NUNES, Carlos Angelo; Coelho,Gilberto Carvalho; Suzuki, Paulo Atsushi

    2010-01-01

    Ti-base alloys containing significant amounts of silicon have been considered for high temperature structural applications. Thus, information concerning phase stability on the Ti-Si system is fundamental and there are not many investigations covering the phase stability of the Ti(3)Si phase, specially its dependence on oxygen/nitrogen contamination. In this work the stability of this phase has been evaluated through heat-treatment of rapidly solidified Ti-rich Ti-Si alloys at 700 A degrees C ...

  1. Colorimetry provides a rapid objective measurement of de novo hair growth rate in mice.

    Science.gov (United States)

    Tzung, Tien-Yi; Yang, Chia-Yi; Huang, Yung-Chang; Kao, Fu-Jen

    2009-11-01

    Depilated mice have been used as a test platform for hair growth-regulating agents. However, currently available assessment tools for hair growth in mice are less than ideal. Tristimulus colorimetry of the fur color of depilated agouti, albino, and black mice with L*, a*, and b* values were performed daily until the full growth of pelage. Using light-emitting diode (LED) irradiation (650 and 890 nm) with a daily dose of 3.5 J/cm(2) as hair growth regulators, the hair growth rates observed by the global assessment were compared with those derived from colorimetry. In contrast to a* and b* values, L* values changed more drastically over time in the anagen phase regardless of fur color. Unlike the inhibitory effect of 650 nm irradiation, LED of 890 nm promoted de novo hair regrowth in mice. The difference in hair growth rates detected by colorimetry paralleled the observation made by the global assessment. The L* value of fur color obtained by tristimulus colorimetry was a sensitive yet quantitative indicator of de novo hair growth, and could be used to project the hair growth rate in mice.

  2. Rapid microwave pyrolysis of coal: methodology and examination of the residual and volatile phases

    Energy Technology Data Exchange (ETDEWEB)

    Monsef-Mirzai, P.; Ravindran, M.; McWhinnie, W.R.; Burchill, P. (Aston University, Birmingham (United Kingdom). Dept. of Chemical Engineering and Applied Chemistry)

    1995-01-01

    Substances such as CuO, Fe[sub 3]O[sub 4] and even metallurgical coke (termed 'receptors') heat rapidly in a microwave oven at 2.45 GHz. The receptor, when mixed with Creswell coal and subjected to microwave radiation, induces rapid pyrolysis of the coal. Condensable tar yields of 20 wt% are obtained with coke, 27 wt% with Fe[sub 3]O[sub 4] and as high as 49 wt% in some experiments with CuO. Despite the high final temperature (1200-1300[degree]C after 3 min), analyses suggest that the volatiles are released in the lower part of the temperature regime but that some secondary cracking does occur. The tars are similar in composition, although with coke the proportion of aromatic hydrogen is greater than with CuO and Fe[sub 3]O[sub 4]. X-ray photoelectron spectroscopy shows that both pyridinic and pyrrolic nitrogen are present in the tars and chars, and that the dominant form of tar sulfur is thiophenic. There is evidence that mineral sulfur is immobilized when CuO in particular is the receptor. The chars formed show a degree of graphitization and are themselves excellent microwave receptors. In the presence of oxide receptors, char-oxide redox reactions occur, with loss of char, reduction of oxide and enhanced yields of CO and CO[sub 2]. Of the lighter hydrocarbons identified in the gas phase, methane predominates. The data obtained are compared with those for other pyrolysis methods. 22 refs., 1 fig., 9 tabs.

  3. A method for rapid measurement of laser ablation rate of hard dental tissue

    Science.gov (United States)

    Perhavec, T.; Gorkič, A.; Bračun, D.; Diaci, J.

    2009-06-01

    The aim of the study reported here is the development of a new method which allows rapid and accurate in-vitro measurements of three-dimensional (3D) shape of laser ablated craters in hard dental tissues and the determination of crater volume, ablation rate and speed. The method is based on the optical triangulation principle. A laser sheet projector illuminates the surface of a tooth, mounted on a linear translation stage. As the tooth is moved by the translation stage a fast digital video camera captures series of images of the illuminated surface. The images are analyzed to determine a 3D model of the surface. Custom software is employed to analyze the 3D model and to determine the volume of the ablated craters. Key characteristics of the method are discussed as well as some practical aspects pertinent to its use. The method has been employed in an in-vitro study to examine the ablation rates and speeds of the two main laser types currently employed in dentistry, Er:YAG and Er,Cr:YSGG. Ten samples of extracted human molar teeth were irradiated with laser pulse energies from 80 mJ to the maximum available energy (970 mJ with the Er:YAG, and 260 mJ with the Er,Cr:YSGG). About 2000 images of each ablated tooth surface have been acquired along a translation range of 10 mm, taking about 10 s and providing close to 1 million surface measurement points. Volumes of 170 ablated craters (half of them in dentine and the other half in enamel) were determined from this data and used to examine the ablated volume per pulse energy and ablation speed. The results show that, under the same conditions, the ablated volume per pulse energy achieved by the Er:YAG laser exceeds that of the Er,Cr:YSGG laser in almost all regimes for dentine and enamel. The maximum Er:YAG laser ablation speeds (1.2 mm 3/s in dentine and 0.7 mm 3/s in enamel) exceed those obtained by the Er,Cr:YSGG laser (0.39 mm 3/s in dentine and 0.12 mm 3/s in enamel). Since the presented method proves to be easy to

  4. The Chaitén rhyolite lava dome: Eruption sequence, lava dome volumes, rapid effusion rates and source of the rhyolite magma

    Science.gov (United States)

    Pallister, John S.; Diefenbach, Angela K.; Burton, William C.; Munoz, Jorge; Griswold, Julia P.; Lara, Luis E.; Lowenstern, Jacob B.; Valenzuela, Carolina E.

    2013-01-01

    We use geologic field mapping and sampling, photogrammetric analysis of oblique aerial photographs, and digital elevation models to document the 2008-2009 eruptive sequence at Chaitén Volcano and to estimate volumes and effusion rates for the lava dome. We also present geochemical and petrologic data that contribute to understanding the source of the rhyolite and its unusually rapid effusion rates. The eruption consisted of five major phases: 1. An explosive phase (1-11 May 2008); 2. A transitional phase (11-31 May 2008) in which low-altitude tephra columns and simultaneous lava extrusion took place; 3. An exogenous lava flow phase (June-September 2008); 4. A spine extrusion and endogenous growth phase (October 2008-February 2009); and 5. A mainly endogenous growth phase that began after the collapse of a prominent Peléean spine on 19 February 2009 and continued until the end of the eruption (late 2009 or possibly earliest 2010). The 2008-2009 rhyolite lava dome has a total volume of approximately 0.8 km3. The effusion rate averaged 66 m3s-1 during the first two weeks and averaged 45 m3s-1 for the first four months of the eruption, during which 0.5 km3 of rhyolite lava was erupted. These are among the highest rates measured world-wide for historical eruptions of silicic lava. Chaitén’s 2008-2009 lava is phenocryst-poor obsidian and microcrystalline rhyolite with 75.3±0.3% SiO2. The lava was erupted at relatively high temperature and is remarkably similar in composition and petrography to Chaitén’s pre-historic rhyolite. The rhyolite’s normative composition plots close to that of low pressure (100-200 MPa) minimum melts in the granite system, consistent with estimates of approximately 5 to 10 km source depths based on phase equilibria and geodetic studies. Calcic plagioclase, magnesian orthopyroxene and aluminous amphibole among the sparse phenocrysts suggest derivation of the rhyolite by melt extraction from a more mafic magmatic mush. High temperature

  5. Rapid experimental SAD phasing and hot-spot identification with halogenated fragments

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, Joseph D.; Harrison, Jerry Joe E. K.; Arnold, Eddy

    2016-01-01

    Through X-ray crystallographic fragment screening, 4-bromopyrazole was discovered to be a `magic bullet' that is capable of binding at many of the ligand `hot spots' found in HIV-1 reverse transcriptase (RT). The binding locations can be in pockets that are `hidden' in the unliganded crystal form, allowing rapid identification of these sites forin silicoscreening. In addition to hot-spot identification, this ubiquitous yet specific binding provides an avenue for X-ray crystallographic phase determination, which can be a significant bottleneck in the determination of the structures of novel proteins. The anomalous signal from 4-bromopyrazole or 4-iodopyrazole was sufficient to determine the structures of three proteins (HIV-1 RT, influenza A endonuclease and proteinase K) by single-wavelength anomalous dispersion (SAD) from single crystals. Both compounds are inexpensive, readily available, safe and very soluble in DMSO or water, allowing efficient soaking into crystals.

  6. False positive rate of rapid oral fluid HIV tests increases as kits near expiration date.

    Science.gov (United States)

    Facente, Shelley N; Dowling, Teri; Vittinghoff, Eric; Sykes, Deanna L; Colfax, Grant N

    2009-12-14

    Because a recent cluster of false positive results on the OraQuick ADVANCE Rapid HIV-1/2 Antibody Test occurred in San Francisco on test kits close to their expiration date, we decided to assess the relationship between time to expiration and rate of false positive results from tests used with oral fluid. We analyzed results of 20,904 tests with either an initial HIV-negative result (n = 20,828) or a preliminary positive result that was then negative on confirmatory tests (n = 76). We computed specificity for kits with time to expiration from or = 6 months, with exact binomial confidence intervals, then used logistic regression to estimate the independent association of time to expiration with false positive results, adjusting for site and technician effects. For 1,108 kits used in the last month before expiration, specificity was 98.83% (95% exact binomial confidence interval (CI) 98.00%-99.37%); the upper bound is below the claimed specificity of 99.60%. After adjustment using regression standardization for the effects of site, test lot, and technician factors, adjusted specificity in the last month before expiration was 99.18% (95% bootstrap confidence interval 98.60-99.57%). We found that specificity of the OraQuick ADVANCE with oral fluid declined significantly with < or = 1 month remaining to expiration, leaving little margin for error from other sources.

  7. Training of Tonal Similarity Ratings in Non-Musicians: A “Rapid Learning” Approach

    Science.gov (United States)

    Oechslin, Mathias S.; Läge, Damian; Vitouch, Oliver

    2012-01-01

    Although cognitive music psychology has a long tradition of expert–novice comparisons, experimental training studies are rare. Studies on the learning progress of trained novices in hearing harmonic relationships are still largely lacking. This paper presents a simple training concept using the example of tone/triad similarity ratings, demonstrating the gradual progress of non-musicians compared to musical experts: In a feedback-based “rapid learning” paradigm, participants had to decide for single tones and chords whether paired sounds matched each other well. Before and after the training sessions, they provided similarity judgments for a complete set of sound pairs. From these similarity matrices, individual relational sound maps, intended to display mental representations, were calculated by means of non-metric multidimensional scaling (NMDS), and were compared to an expert model through procrustean transformation. Approximately half of the novices showed substantial learning success, with some participants even reaching the level of professional musicians. Results speak for a fundamental ability to quickly train an understanding of harmony, show inter-individual differences in learning success, and demonstrate the suitability of the scaling method used for learning research in music and other domains. Results are discussed in the context of the “giftedness” debate. PMID:22629252

  8. Training of tonal similarity ratings in non-musicians: a rapid learning approach

    Directory of Open Access Journals (Sweden)

    Mathias S Oechslin

    2012-05-01

    Full Text Available Although music psychology has a long tradition of expert-novice comparisons, experimental training studies are rare. Studies on the learning progress of trained novices in hearing harmonic relationships are still largely lacking. This paper presents a simple training concept using the example of tone/triad similarity ratings, demonstrating the gradual progress of non-musicians compared to musical experts: In a feedback-based rapid learning paradigm, participants had to decide for single tones and chords whether paired sounds matched each other well. Before and after the training sessions, they provided similarity judgments for a complete set of sound pairs. From these similarity matrices, individual relational sound maps, aiming to map the mental representations, were calculated by means of non-metric multidimensional scaling (NMDS, which were compared to an expert model through procrustean transformation. Approximately half of the novices showed substantial learning success, with some participants even reaching the level of professional musicians. Results speak for a fundamental ability to quickly train an understanding of harmony, show inter-individual differences in learning success, and demonstrate the suitability of the scaling method used for music psychological research. Results are discussed in the context of the giftedness debate.

  9. Training of tonal similarity ratings in non-musicians: a "rapid learning" approach.

    Science.gov (United States)

    Oechslin, Mathias S; Läge, Damian; Vitouch, Oliver

    2012-01-01

    Although cognitive music psychology has a long tradition of expert-novice comparisons, experimental training studies are rare. Studies on the learning progress of trained novices in hearing harmonic relationships are still largely lacking. This paper presents a simple training concept using the example of tone/triad similarity ratings, demonstrating the gradual progress of non-musicians compared to musical experts: In a feedback-based "rapid learning" paradigm, participants had to decide for single tones and chords whether paired sounds matched each other well. Before and after the training sessions, they provided similarity judgments for a complete set of sound pairs. From these similarity matrices, individual relational sound maps, intended to display mental representations, were calculated by means of non-metric multidimensional scaling (NMDS), and were compared to an expert model through procrustean transformation. Approximately half of the novices showed substantial learning success, with some participants even reaching the level of professional musicians. Results speak for a fundamental ability to quickly train an understanding of harmony, show inter-individual differences in learning success, and demonstrate the suitability of the scaling method used for learning research in music and other domains. Results are discussed in the context of the "giftedness" debate.

  10. Rapid yet accurate measurement of mass diffusion coefficients by phase shifting interferometer

    CERN Document Server

    Guo Zhi Xiong; Komiya, A

    1999-01-01

    The technique of using a phase-shifting interferometer is applied to the study of diffusion in transparent liquid mixtures. A quick method is proposed for determining the diffusion coefficient from the measurements of the location of fringes on a grey level picture. The measurement time is very short (within 100 s) and a very small transient diffusion field can be observed and recorded accurately with a rate of 30 frames per second. The measurement can be completed using less than 0.12 cc of solutions. The influence of gravity on the measurement of the diffusion coefficient is eliminated in the present method. Results on NaCl-water diffusion systems are presented and compared with the reference data. (author)

  11. Interaction of a magnetic island chain in a tokamak plasma with a resonant magnetic perturbation of rapidly oscillating phase

    Science.gov (United States)

    Fitzpatrick, Richard

    2017-12-01

    An investigation is made into the interaction of a magnetic island chain, embedded in a tokamak plasma, with an externally generated magnetic perturbation of the same helicity whose helical phase is rapidly oscillating. The analysis is similar in form to the classic analysis used by Kapitza [Sov. Phys. JETP 21, 588 (1951)] to examine the angular motion of a rigid pendulum whose pivot point undergoes rapid vertical oscillations. The phase oscillations are found to modify the existing terms, and also to give rise to new terms, in the equations governing the secular evolution of the island chain's radial width and helical phase. An examination of the properties of the new secular evolution equation reveals that it is possible to phase-lock an island chain to an external magnetic perturbation with an oscillating helical phase in a stabilizing phase relation provided that the amplitude, ɛ, of the phase oscillations (in radians) is such that |J0(ɛ )|≪1 , and the mean angular frequency of the perturbation closely matches the natural angular frequency of the island chain.

  12. Rapid removal of nitrobenzene in a three-phase ozone loaded system with gas-liquid-liquid

    Science.gov (United States)

    Li, Shiyin; Zhu, Jiangpeng; Wang, Guoxiang; Ni, Lixiao; Zhang, Yong; Green, Christopher T.

    2015-01-01

    This study explores the removal rate of nitrobenzene (NB) using a new gas-liquid-liquid (G-L-L) three-phase ozone loaded system consisting of a gaseous ozone, an aqueous solvent phase, and a fluorinated solvent phase (perfluorodecalin, or FDC). The removal rate of NB was quantified in relation to six factors including 1) initial pH, 2) initial NB dosage, 3) gaseous ozone dosage, 4) free radical scavenger, 5) FDC pre-aerated gaseous ozone, and 6) reuse of FDC. The NB removal rate is positively affected by the first three factors. Compared with the conventional gas-liquid (water) (G-L) two-phase ozonation system, the free radical scavenger (tertiary butyl alcohol) has much less influence on the removal rate of NB in the G-L-L system. The FDC loaded ozone acts as an ozone reservoir and serves as the main reactive phase in the G-L-L three-phase system. The reuse of FDC has little influence on the removal rate of NB. These experimental results suggest that the oxidation efficiency of ozonation in the G-L-L three-phase system is better than that in the conventional G-L two-phase system.

  13. Rapid Separation of Elemental Species by Fast Multicapillary Gas Chromatography with Multichannel Optical Spectrometry Detection following Headspace Solid Phase Microextraction

    Directory of Open Access Journals (Sweden)

    Jacek Giersz

    2015-05-01

    Full Text Available A method for conducting fast and efficient gas chromatography based on short multicapillaries in straight alignment combined with atomic emission detection was developed for field analysis. The strategy enables for speciation analysis of organometallic compounds. The analytes are simultaneously ethylated and preconcentrated on a solid phase microextraction (SPME fiber placed in the headspace over the sample for 25 min. The ethylated species are then completely separated and selectively quantified within 25 s under isothermal conditions. A new miniaturized speciation analyzer has been constructed and evaluated. The system consists of a GC injection port and a lab-made miniaturized GC unit directly coupled with miniaturized plasma excitation source. The emitted light is transferred via optical fiber and registered with a miniaturized charged coupled device (CCD based spectrometer. Working parameters for multicapillary column gas chromatography with atomic emission detector, including carrier gas flow rate, desorption temperature, and GC column temperature, were optimized to achieve good separation of analytes. Basic investigations of the fundamental properties of 5 cm-long multicapillary column, to evaluate its potential and limitations as a rapid separation unit, are presented. The adaptation of the technique for use with a SPME system and with a multichannel element-selective plasma-emission detector is highlighted.

  14. Dynamic phase-sensitive optical coherence elastography at a true kilohertz frame-rate

    Science.gov (United States)

    Singh, Manmohan; Wu, Chen; Liu, Chih-Hao; Li, Jiasong; Schill, Alexander; Nair, Achuth; Larin, Kirill V.

    2016-03-01

    Dynamic optical coherence elastography (OCE) techniques have rapidly emerged as a noninvasive way to characterize the biomechanical properties of tissue. However, clinical applications of the majority of these techniques have been unfeasible due to the extended acquisition time because of multiple temporal OCT acquisitions (M-B mode). Moreover, multiple excitations, large datasets, and prolonged laser exposure prohibit their translation to the clinic, where patient discomfort and safety are critical criteria. Here, we demonstrate the feasibility of noncontact true kilohertz frame-rate dynamic optical coherence elastography by directly imaging a focused air-pulse induced elastic wave with a home-built phase-sensitive OCE system. The OCE system was based on a 4X buffered Fourier Domain Mode Locked swept source laser with an A-scan rate of ~1.5 MHz, and imaged the elastic wave propagation at a frame rate of ~7.3 kHz. Because the elastic wave directly imaged, only a single excitation was utilized for one line scan measurement. Rather than acquiring multiple temporal scans at successive spatial locations as with previous techniques, here, successive B-scans were acquired over the measurement region (B-M mode). Preliminary measurements were taken on tissue-mimicking agar phantoms of various concentrations, and the results showed good agreement with uniaxial mechanical compression testing. Then, the elasticity of an in situ porcine cornea in the whole eye-globe configuration at various intraocular pressures was measured. The results showed that this technique can acquire a depth-resolved elastogram in milliseconds. Furthermore, the ultra-fast acquisition ensured that the laser safety exposure limit for the cornea was not exceeded.

  15. Regulation of the Escherichia coli rmf gene encoding the ribosome modulation factor: growth phase- and growth rate-dependent control.

    Science.gov (United States)

    Yamagishi, M; Matsushima, H; Wada, A; Sakagami, M; Fujita, N; Ishihama, A

    1993-02-01

    Ribosome modulation factor (RMF) is a protein specifically associated with 100S ribosome dimers which start to accumulate in Escherichia coli cells upon growth transition from exponential to stationary phase. The structural gene, rmf, encoding the 55 amino acid residues RMF protein has been cloned from the 21.8 min region of the E. coli genome and sequenced. While rmf was silent in rapidly growing exponential phase cells, a high level of transcription took place concomitantly with the growth transition to stationary phase. Under slow growth conditions, rmf was expressed even in exponential phase and there was an inverse relationship between the expression of rmf and the cell growth rate. Thus, the expression profile of rmf is contrary to those of genes for ribosomal components and ribosome-associated proteins constituting the translational apparatus. The katF gene product, a stationary phase-specific sigma factor, was not required for the expression of rmf. Disruption of rmf resulted in loss of ribosome dimers and reduction of cell viability during stationary phase.

  16. Field measurement of erosion rates: time-lapse monitoring of rapid stone flaking at Howden Minster, UK

    Science.gov (United States)

    Doehne, E.; Pinchin, S.

    2012-04-01

    The use of a solar-powered, field time-lapse camera and environmental monitoring system enabled measurements of the pattern and rate of loss of stone from the surface of Howden Minster, an abandoned monastery in Yorkshire dating to 1380 AD. Acquiring a photograph every 1-3 hours allowed the stone damage to be correlated with local environmental conditions. Image comparison techniques borrowed from observational astronomy, such as blink comparison, were used to determine what elements had changed from image to image. Results indicate that loss is episodic rather than continuous and in several cases is related to specific environmental conditions, such as condensation/dew formation or high winds. Damage was found also to be synchronous, with surface change (flaking, granular disintegration, and loss of flakes) occurring at the same time on different stone blocks. Crystallization pressure from magnesium sulfate phase transitions appear to be the main cause of the loss of stone surfaces. Significant variation in surface loss rates was observed and appears to be related to variations in salt concentration. An examination of stone texture by ESEM/EDS revealed signification variations and suggests that salt concentrations are controlled in part by stone micromorphology. Quantitative data on rates of surface loss are not available from most monuments. Time-lapse methods permit the relatively inexpensive acquisition of this type of data, which is needed to aid conservation decision-making and the evaluation of interventions. Such tools should also prove useful to geomorphologists studying honeycomb weathering, the moving rocks on Death Valley's Racetrack Playa, and other phenomena that are otherwise difficult to study. Context: The rapid deterioration of magnesian limestone structures in the north of England has been a serious problem for more than one hundred years. While air quality in England has improved during this period, the rate of stone loss in these carved stone

  17. Rapid T1 quantification based on 3D phase sensitive inversion recovery.

    Science.gov (United States)

    Warntjes, Marcel J B; Kihlberg, Johan; Engvall, Jan

    2010-08-17

    In Contrast Enhanced Magnetic Resonance Imaging fibrotic myocardium can be distinguished from healthy tissue using the difference in the longitudinal T1 relaxation after administration of Gadolinium, the so-called Late Gd Enhancement. The purpose of this work was to measure the myocardial absolute T1 post-Gd from a single breath-hold 3D Phase Sensitivity Inversion Recovery sequence (PSIR). Equations were derived to take the acquisition and saturation effects on the magnetization into account. The accuracy of the method was investigated on phantoms and using simulations. The method was applied to a group of patients with suspected myocardial infarction where the absolute difference in relaxation of healthy and fibrotic myocardium was measured at about 15 minutes post-contrast. The evolution of the absolute R1 relaxation rate (1/T1) over time after contrast injection was followed for one patient and compared to T1 mapping using Look-Locker. Based on the T1 maps synthetic LGE images were reconstructed and compared to the conventional LGE images. The fitting algorithm is robust against variation in acquisition flip angle, the inversion delay time and cardiac arrhythmia. The observed relaxation rate of the myocardium is 1.2 s-1, increasing to 6 - 7 s-1 after contrast injection and decreasing to 2 - 2.5 s-1 for healthy myocardium and to 3.5 - 4 s-1 for fibrotic myocardium. Synthesized images based on the T1 maps correspond very well to actual LGE images. The method provides a robust quantification of post-Gd T1 relaxation for a complete cardiac volume within a single breath-hold.

  18. Performance of a Rapid and Simple HIV Testing Algorithm in a Multicenter Phase III Microbicide Clinical Trial▿

    OpenAIRE

    Crucitti, Tania; Taylor, Doug; Beelaert, Greet; Fransen, Katrien; Van Damme, Lut

    2011-01-01

    A multitest sequential algorithm based on rapid and simple (R/S) assays was applied for the diagnosis of HIV infection among participants in a phase 3 microbicide effectiveness trial. HIV testing was performed on finger-prick blood samples obtained from patients after their enrollment in the trial. The specimens were tested in a serial procedure using three different rapid tests (Determine HIV-1/2 [Abbott], SD Bioline HIV-1/2 3.0 [Standard Diagnostics], and Uni-Gold HIV [Trinity Biotech]). In...

  19. Rapid 2D phase-contrast magnetic resonance angiography reconstruction algorithm via compressed sensing

    Science.gov (United States)

    Lee, Dong-Hoon; Hong, Cheol-Pyo; Lee, Man-Woo; Han, Bong-Soo

    2013-09-01

    Phase-contrast magnetic resonance angiography (PC MRA) is an excellent technique for visualization of venous vessels. However, the scan time of PC MRA is long compared with there of other MRA techniques. Recently, the potential of compressed sensing (CS) reconstruction to reduce the scan time in MR image acquisition using a sparse sampling dataset has become an active field of study. In this study, we propose a combination method to apply the CS reconstruction method to 2D PC MRA. This work was performed to enable faster 2D PC MRA imaging acquisition and to demonstrate its feasibility. We used a 0.32 T MR imaging (MRI) system and a total variation (TV)-based CS reconstruction algorithm. To validate the usefulness of our proposed reconstruction method, we used visual assessment for reconstructed images, and we measured the quantitative information for sampling rates from 12.5 to 75.0%. Based on our results, when the sampling ratio is increased, images reconstructed with the CS method have a similar level of image quality to fully sampled reconstruction images. The signal to noise ratio (SNR) and the contrast-to-noise ratio (CNR) were also closer to the reference values when the sampling ratio was increased. We confirmed the feasibility of 2D PC MRA with the CS reconstruction method. Our results provide evidence that this method can improve the time resolution of 2D PC MRA.

  20. Rapid stimulation of fluid-phase endocytosis and exocytosis by insulin, insulin-like growth factor-I, and epidermal growth factor in KB cells.

    Science.gov (United States)

    Miyata, Y; Hoshi, M; Koyasu, S; Kadowaki, T; Kasuga, M; Yahara, I; Nishida, E; Sakai, H

    1988-09-01

    Effects of growth factors on fluid-phase endocytosis and exocytosis in human epidermoid carcinoma KB cells were examined by measuring horseradish peroxidase (HRP) as a marker. Insulin, insulin-like growth factor-I (IGF-I), and epidermal growth factor (EGF) promoted HRP accumulation. They also stimulated the efflux of the preloaded HRP from the cells. From these results it follows that these growth factors stimulate the influx as well as the efflux of HRP, because the accumulation rate is the sum of the influx rate and the efflux rate. The stimulation of both HRP accumulation and HRP efflux was rapidly induced within 2-4 min of the addition of growth factors and persisted for at least 60 min. The concentrations eliciting half-maximal stimulatory effects of insulin, IGF-I, and EGF were about 5 X 10(-7), 1 X 10(-9), and 5 X 10(-10) M, respectively. aIR-3 (anti-type I IGF receptor antibody) completely blocked the stimulation of HRP accumulation by IGF-I but very slightly inhibited the stimulation by insulin. The 528 IgG (anti-EGF receptor antibody) inhibited the stimulation of HRP accumulation by EGF. These results indicated that each of these growth factors stimulates the HRP accumulation mediated by the corresponding (homologous) growth factor receptors. The rapid stimulation of fluid-phase influx and efflux may constitute one of the common early cellular responses to growth factors.

  1. Rapid detoxification from opioid dependence under general anaesthesia versus standard methadone tapering: abstinence rates and withdrawal distress experiences.

    NARCIS (Netherlands)

    Krabbe, P.F.M.; Koning, J.P.; Heinen, N.; Laheij, R.J.F.; Cauter, R.M.V. van; Jong, C.A.J. de

    2003-01-01

    The aim of this work was to study abstinence rates and withdrawal effects of rapid detoxification of opioid-dependents under general anaesthesia (RD-GA) compared to standard methadone tapering (SMT) using a prospective clinical trial with a follow-up of 3 months, as a preliminary study at the

  2. Rapid detoxification from opioid dependence under general anaesthesia versus standard methadone tapering : abstinence rates and withdrawal distress experiences

    NARCIS (Netherlands)

    Krabbe, Paul F M; Koning, Jeroen P F; Heinen, Nadia; Laheij, Robert J F; van Cauter, R M Victory; De Jong, Cor A J

    The aim of this work was to study abstinence rates and withdrawal effects of rapid detoxification of opioid-dependents under general anaesthesia (RD-GA) compared to standard methadone tapering (SMT) using a prospective clinical trial with a follow-up of 3 months, as a preliminary study at the

  3. Process for rapid detection of fratricidal defects on optics using Linescan Phase Differential Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ravizza, F L; Nostrand, M C; Kegelmeyer, L M; Hawley, R A; Johnson, M A

    2009-11-05

    Phase-defects on optics used in high-power lasers can cause light intensification leading to laser-induced damage of downstream optics. We introduce Linescan Phase Differential Imaging (LPDI), a large-area dark-field imaging technique able to identify phase-defects in the bulk or surface of large-aperture optics with a 67 second scan-time. Potential phase-defects in the LPDI images are indentified by an image analysis code and measured with a Phase Shifting Diffraction Interferometer (PSDI). The PSDI data is used to calculate the defects potential for downstream damage using an empirical laser-damage model that incorporates a laser propagation code. A ray tracing model of LPDI was developed to enhance our understanding of its phase-defect detection mechanism and reveal limitations.

  4. Phase selection and nanocrystallization in Cu-free soft magnetic FeSiNbB amorphous alloy upon rapid annealing

    Energy Technology Data Exchange (ETDEWEB)

    Morsdorf, L.; Povstugar, I.; Raabe, D. [Department for Microstructure Physics and Alloy Design, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf (Germany); Pradeep, K. G., E-mail: kg.prad@mpie.de, E-mail: kgprad@gmail.com [Department for Microstructure Physics and Alloy Design, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf (Germany); Materials Chemistry, RWTH Aachen University, Kopernikusstrasse 10, 52074 Aachen (Germany); Herzer, G. [Vacuumschmelze GmbH & Co KG, Grüner Weg 37, D-63450 Hanau (Germany); Kovács, A.; Dunin-Borkowski, R. E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute 5, Forschungszentrum Jülich, 52425 Jülich (Germany); Konygin, G. [Physical-Technical Institute UrB RAS, Kirov str. 132, 426008 Izhevsk (Russian Federation); Choi, P. [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141 (Korea, Republic of)

    2016-03-28

    Nucleation of soft magnetic Fe{sub 3}Si nanocrystals in Cu-free Fe{sub 74.5}Si{sub 15.5}Nb{sub 3}B{sub 7} alloy, upon rapid (10 s) and conventional (30 min) annealing, was investigated using x-ray diffraction, transmission electron microscopy, Mössbauer spectroscopy, and atom probe tomography. By employing rapid annealing, preferential nucleation of Fe{sub 3}Si nanocrystals was achieved, whereas otherwise there is simultaneous nucleation of both Fe{sub 3}Si and undesired Fe-B compound phases. Analysis revealed that the enhanced Nb diffusivity, achieved during rapid annealing, facilitates homogeneous nucleation of Fe{sub 3}Si nanocrystals while shifting the secondary Fe-B crystallization to higher temperatures resulting in pure soft magnetic nanocrystallization with very low coercivities of ∼10 A/m.

  5. Rapid estimation of glucosinolate thermal degradation rate constants in leaves of Chinese kale and broccoli (Brassica oleracea) in two seasons.

    Science.gov (United States)

    Hennig, Kristin; Verkerk, Ruud; Bonnema, Guusje; Dekker, Matthijs

    2012-08-15

    Kinetic modeling was used as a tool to quantitatively estimate glucosinolate thermal degradation rate constants. Literature shows that thermal degradation rates differ in different vegetables. Well-characterized plant material, leaves of broccoli and Chinese kale plants grown in two seasons, was used in the study. It was shown that a first-order reaction is appropriate to model glucosinolate degradation independent from the season. No difference in degradation rate constants of structurally identical glucosinolates was found between broccoli and Chinese kale leaves when grown in the same season. However, glucosinolate degradation rate constants were highly affected by the season (20-80% increase in spring compared to autumn). These results suggest that differences in glucosinolate degradation rate constants can be due to variation in environmental as well as genetic factors. Furthermore, a methodology to estimate rate constants rapidly is provided to enable the analysis of high sample numbers for future studies.

  6. GNSS seismometer: Seismic phase recognition of real-time high-rate GNSS deformation waves

    Science.gov (United States)

    Nie, Zhaosheng; Zhang, Rui; Liu, Gang; Jia, Zhige; Wang, Dijin; Zhou, Yu; Lin, Mu

    2016-12-01

    High-rate global navigation satellite systems (GNSS) can potentially be used as seismometers to capture short-period instantaneous dynamic deformation waves from earthquakes. However, the performance and seismic phase recognition of the GNSS seismometer in the real-time mode, which plays an important role in GNSS seismology, are still uncertain. By comparing the results of accuracy and precision of the real-time solution using a shake table test, we found real-time solutions to be consistent with post-processing solutions and independent of sampling rate. In addition, we analyzed the time series of real-time solutions for shake table tests and recent large earthquakes. The results demonstrated that high-rate GNSS have the ability to retrieve most types of seismic waves, including P-, S-, Love, and Rayleigh waves. The main factor limiting its performance in recording seismic phases is the widely used 1-Hz sampling rate. The noise floor also makes recognition of some weak seismic phases difficult. We concluded that the propagation velocities and path of seismic waves, macro characteristics of the high-rate GNSS array, spatial traces of seismic phases, and incorporation of seismographs are all useful in helping to retrieve seismic phases from the high-rate GNSS time series.

  7. Severe Sepsis Manifesting as A-Fib with Rapid Ventricular Rate

    Directory of Open Access Journals (Sweden)

    Paul Nicholson

    2018-01-01

    Full Text Available Audience: This simulation is designed to educate emergency medicine residents and medical students on the diagnosis and management of an adult patient with sepsis due to a decubitus ulcer manifesting as acute-onset atrial fibrillation (A-fib with rapid ventricular response (RVR. Introduction: Adult patients frequently present critically ill from sepsis. Proper diagnosis and management require a focused but thorough history and physical exam, as well as an appropriate diagnostic workup. Management includes aggressive care with antibiotics and intravenous fluids, and may require vasoactive agents. Objectives: Learners will be able to identify and manage atrial fibrillation with rapid ventricular response. Additionally, learners will be able to identify the concurrent infection and determine the appropriate management in the setting of A-fib with RVR. The case also provides learners with the opportunity to review principles of leadership, teamwork, and effective communication. Method: This session was conducted using high-fidelity simulation, followed by a debriefing session.

  8. Luteal phase of the menstrual cycle increases sweating rate during exercise

    Directory of Open Access Journals (Sweden)

    Garcia A.M.C.

    2006-01-01

    Full Text Available The present study evaluated whether the luteal phase elevation of body temperature would be offset during exercise by increased sweating, when women are normally hydrated. Eleven women performed 60 min of cycling exercise at 60% of their maximal work load at 32ºC and 80% relative air humidity. Each subject participated in two identical experimental sessions: one during the follicular phase (between days 5 and 8 and the other during the luteal phase (between days 22 and 25. Women with serum progesterone >3 ng/mL, in the luteal phase were classified as group 1 (N = 4, whereas the others were classified as group 2 (N = 7. Post-exercise urine volume (213 ± 80 vs 309 ± 113 mL and specific urine gravity (1.008 ± 0.003 vs 1.006 ± 0.002 changed (P < 0.05 during the luteal phase compared to the follicular phase in group 1. No menstrual cycle dependence was observed for these parameters in group 2. Sweat rate was higher (P < 0.05 in the luteal (3.10 ± 0.81 g m-2 min-1 than in the follicular phase (2.80 ± 0.64 g m-2 min-1 only in group 1. During exercise, no differences related to menstrual cycle phases were seen in rectal temperature, heart rate, rate of perceived exertion, mean skin temperature, and pre- and post-exercise body weight. Women exercising in a warm and humid environment with water intake seem to be able to adapt to the luteal phase increase of basal body temperature through reduced urinary volume and increased sweating rate.

  9. Luteal phase of the menstrual cycle increases sweating rate during exercise

    Directory of Open Access Journals (Sweden)

    A.M.C. Garcia

    Full Text Available The present study evaluated whether the luteal phase elevation of body temperature would be offset during exercise by increased sweating, when women are normally hydrated. Eleven women performed 60 min of cycling exercise at 60% of their maximal work load at 32ºC and 80% relative air humidity. Each subject participated in two identical experimental sessions: one during the follicular phase (between days 5 and 8 and the other during the luteal phase (between days 22 and 25. Women with serum progesterone >3 ng/mL, in the luteal phase were classified as group 1 (N = 4, whereas the others were classified as group 2 (N = 7. Post-exercise urine volume (213 ± 80 vs 309 ± 113 mL and specific urine gravity (1.008 ± 0.003 vs 1.006 ± 0.002 changed (P < 0.05 during the luteal phase compared to the follicular phase in group 1. No menstrual cycle dependence was observed for these parameters in group 2. Sweat rate was higher (P < 0.05 in the luteal (3.10 ± 0.81 g m-2 min-1 than in the follicular phase (2.80 ± 0.64 g m-2 min-1 only in group 1. During exercise, no differences related to menstrual cycle phases were seen in rectal temperature, heart rate, rate of perceived exertion, mean skin temperature, and pre- and post-exercise body weight. Women exercising in a warm and humid environment with water intake seem to be able to adapt to the luteal phase increase of basal body temperature through reduced urinary volume and increased sweating rate.

  10. Rapid replacement of bridge deck expansion joints study - phase I : [tech transfer summary].

    Science.gov (United States)

    2014-12-01

    This initial research phase focused on documenting the current : means and methods of bridge expansion joint deterioration, : maintenance, and replacement and on identifying improvements : through all of the input gathered.

  11. Rapid and widely disseminated acute phase protein response after experimental bacterial infection of pigs

    DEFF Research Database (Denmark)

    Skovgaard, Kerstin; Mortensen, Shila; Boye, Mette

    2009-01-01

    The acute phase protein response is a well-described generalized early host response to tissue injury, inflammation and infection, observed as pronounced changes in the concentrations of a number of circulating serum proteins. The biological function of this response and its interplay with other...... infection in pigs. The lung infection was established with the pig specific respiratory pathogen Actinobacillus pleuropneumoniae. Quantitative real-time PCR based expression analysis were performed on samples from liver, tracheobronchial lymph node, tonsils, spleen and on blood leukocytes, supplemented...... with measurements of interleukin-6 and selected acute phase proteins in serum. C-reactive protein and serum amyloid A were clearly induced 14-18 h after infection. Extrahepatic expression of acute phase proteins was found to be dramatically altered as a result of the lung infection with an extrahepatic acute phase...

  12. Novel ultra-rapid freezing particle engineering process for enhancement of dissolution rates of poorly water-soluble drugs.

    Science.gov (United States)

    Overhoff, Kirk A; Engstrom, Josh D; Chen, Bo; Scherzer, Brian D; Milner, Thomas E; Johnston, Keith P; Williams, Robert O

    2007-01-01

    An ultra-rapid freezing (URF) technology has been developed to produce high surface area powders composed of solid solutions of an active pharmaceutical ingredient (API) and a polymer stabilizer. A solution of API and polymer excipient(s) is spread on a cold solid surface to form a thin film that freezes in 50 ms to 1s. This study provides an understanding of how the solvent's physical properties and the thin film geometry influence the freezing rate and consequently the final physico-chemical properties of URF-processed powders. Theoretical calculations of heat transfer rates are shown to be in agreement with infrared images with 10ms resolution. Danazol (DAN)/polyvinylpyrrolidone (PVP) powders, produced from both acetonitrile (ACN) and tert-butanol (T-BUT) as the solvent, were amorphous with high surface areas (approximately 28-30 m2/g) and enhanced dissolution rates. However, differences in surface morphology were observed and attributed to the cooling rate (film thickness) as predicted by the model. Relative to spray-freezing processes that use liquid nitrogen, URF also offers fast heat transfer rates as a result of the intimate contact between the solution and cold solid surface, but without the complexity of cryogen evaporation (Leidenfrost effect). The ability to produce amorphous high surface area powders with submicron primary particles with a simple ultra-rapid freezing process is of practical interest in particle engineering to increase dissolution rates, and ultimately bioavailability.

  13. Rapid phase-modulated water-excitation steady-state free precession for fat-suppressed cine cardiovascular MR

    Directory of Open Access Journals (Sweden)

    Raman Subha V

    2008-05-01

    Full Text Available Abstract Background The purpose of this article is to describe a steady-state free precession (SSFP sequence for fat-suppressed cine cardiovascular magnetic resonance (CMR. A rapid phase-modulated binomial water-excitation (WE pulse is utilized to minimize repetition time and acquisition time. Methods Three different water-excitation pulses were combined with cine-SSFP for evaluation. The frequency response of each sequence was simulated and examined in phantom imaging studies. The ratio of fat to water signal amplitude was measured in phantoms to evaluate the fat-suppression capabilities of each method. Six volunteers underwent CMR of the heart at 1.5T to compare retrospectively-gated cine-SSFP with and without water-excitation. The ratio of fat to myocardium signal amplitude was measured for conventional cine-SSFP and phase-modulated WE-SSFP. The proposed WE-SSFP method was tested in one patient referred for CMR to characterize a cardiac mass. Results and discussion The measured frequency response in a phantom corresponded to the numerical Bloch equation simulation demonstrating the widened stop-band around the fat resonant frequency for all water-excitation pulses tested. In vivo measurements demonstrated that a rapid, phase-modulated water-excitation pulse significantly reduced the signal amplitude ratio of fat to myocardium from 6.92 ± 2.9 to 0.8 ± 0.13 (mean ± SD without inducing any perceptible artifacts in SSFP cine CMR. Conclusion fat-suppression can be achieved in SSFP cine CMR while maintaining steady-state equilibrium using rapid, phase modulated, binomial water-excitation pulses.

  14. Rapid activated sludge respiration inhibition test performed by CO2 producing rate using a carbon dioxide sensor.

    Science.gov (United States)

    Narita, Noboru; Takahashi, Mitsuo; Shoji, Ryo

    2005-01-01

    The rapid activated sludge inhibition test (rapid ASRI) is one of the promising bioassays to evaluate environmental risk to the ecosystem caused by various pollutants. To improve the sensitivity and stability of ASRI, the CO2 producing rate (CPR) using a carbon dioxide gas sensor was employed to examine the respiration activity of activated sludge and to compare it to that by the conventional activated sludge respiration inhibition test using oxygen uptake rate (OUR) by EC50 values derived from dose response curve. Detection of respiratory activity based on CPR has higher reliability and sensitivity than that of OUR. It should be noted that the sensitivity of CPR for evaluating toxicity is sufficiently high in terms of derived dose response curve of some model environmental pollutants and the resultant EC50 values.

  15. Single frame profilometry with rapid phase demodulation on colour-coded fringes

    Science.gov (United States)

    Yee, Cong Kai; Yen, Kin Sam

    2017-08-01

    Digital fringe profilometry is a non-contact surface profiling technique with huge potential at real-time dynamic whole-field measurement. However, this technique is usually bottlenecked at the phase demodulation and unwrapping during fringe analysis. This paper proposes a single frame profilometry system that used direct arccosine function demodulation on colour-coded sinusoidal fringes to simplify the fringe analysis process. Since the range of arccosine function output is restricted from 0 to π, the intensity gradient was used along with arccosine function to demodulate the fringe intensity levels into wrapped phase map (0-2π). The projected fringes were coloured in red, green and blue according to the De Bruijn's sequence. The fringe order was identified directly from the colours of three consecutive fringes by matching to the De Bruijn's sequence to unwrap the wrapped phase map into continuous phase map. The phase differences between the continuous phase maps of reference plane and object surface were then obtained and related to the equipment setup position using trigonometry to rebuild the 3D model. The proposed method was tested experimentally by reconstructing three physical objects. Although the reconstructed surface contained phase errors due to gamma non-linearity, the geometrical shapes of the objects can be reconstructed with reasonable accuracy and consistency. The percentage deviations of dimensions in x, y and z-axis were 1.24%, -1.96% and -2.30% respectively. Meanwhile the uncertainties of dimensions in x, y and z-axis were ±0.15%, ±0.24% and ±1.07% respectively at 95% confidence level.

  16. Melting and crystallization of poly(3-hydroxybutyrate: effect of heating/cooling rates on phase transformation

    Directory of Open Access Journals (Sweden)

    Renate Maria Ramos Wellen

    2015-06-01

    Full Text Available AbstractWe studied the crystallization and melting phenomena of poly (3- hydroxybutyrate (PHB, a biodegradable and biocompatible semi-crystalline thermoplastic, obtained from renewable resources. Its high crystallinity motivated several studies on crystallization and melting behavior, and also on ways to increase the amorphous polymer fraction. The effect of heating and cooling rates on the crystallization and melting of commercial PHB was investigated by differential scanning calorimetry. Several rates, ranging from 2.5 to 20 °C min–1, were used to study the phase changes during heating/cooling/reheating cycles. The results showed that PHB partially crystallizes from the melt during the cooling cycle and partially cold crystallizes on reheating, and that the relative amount of polymer crystallizing in each stage strongly depends on the cooling rate. The melt and cold crystallization temperatures, as well as the rates of phase change, depend strongly on the cooling and heating rates.

  17. Quiescent-phase evolution of a surge-type glacier: Black Rapids Glacier, Alaska, U.S.A.

    Science.gov (United States)

    Heinrichs, T.A.; Mayo, L.R.; Echelmeyer, K.A.; Harrison, W.D.

    1996-01-01

    Black Rapids Glacier, a surge-type glacier in the Alaska Range, most recently surged in 1936-37 and is currently in its quiescent phase. Mass balance, ice velocity and thickness change have been measured at three to ten sites from 1972 to 1994. The annual speed has undergone cyclical fluctuations of as much as 45% about the mean speed. Ice thickness and surface slope did not change enough to cause the speed fluctuations through changes in ice deformation, which indicates that they are being driven by changes in basal motion. The behavior of Black Rapids Glacier during this quiescent phase is significantly different from that of Variegated Glacier, another well-studied surge-type glacier in Alaska. The present medial-moraine configuration of Black Rapids Glacier indicates that a surge could occur at any time. However, ice velocity data indicate that the next surge may not be imminent. We believe that there is little chance that the next surge will cross and dam the Delta River.

  18. Rapid growth reduces cold resistance: evidence from latitudinal variation in growth rate, cold resistance and stress proteins.

    Science.gov (United States)

    Stoks, Robby; De Block, Marjan

    2011-02-24

    Physiological costs of rapid growth may contribute to the observation that organisms typically grow at submaximal rates. Although, it has been hypothesized that faster growing individuals would do worse in dealing with suboptimal temperatures, this type of cost has never been explored empirically. Furthermore, the mechanistic basis of the physiological costs of rapid growth is largely unexplored. Larvae of the damselfly Ischnura elegans from two univoltine northern and two multivoltine southern populations were reared at three temperatures and after emergence given a cold shock. Cold resistance, measured by chill coma recovery times in the adult stage, was lower in the southern populations. The faster larval growth rates in the southern populations contributed to this latitudinal pattern in cold resistance. In accordance with their assumed role in cold resistance, Hsp70 levels were lower in the southern populations, and faster growing larvae had lower Hsp70 levels. Yet, individual variation in Hsp70 levels did not explain variation in cold resistance. WE PROVIDE EVIDENCE FOR A NOVEL COST OF RAPID GROWTH: reduced cold resistance. Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates. This also illustrates that stressors imposed in the larval stage may carry over and shape fitness in the adult stage and highlights the importance of physiological costs in the evolution of life-histories at macro-scales.

  19. Designs to balance cost and success rate for an early phase clinical study.

    Science.gov (United States)

    Foo, Lee Kien; Duffull, Stephen

    2017-01-01

    We present an initial exploration of a fully cost-driven design. A design criterion was proposed that represented the minimum expected cost of an early phase clinical study, where costs include resource use as well as study failure. The design was based on attainment of a target concentration in a cohort of study participants. The model and parameter values arose from a previous population pharmacokinetic analysis of a phase I study. The resulting design naturally balanced the cost and the success rate of an early phase clinical study, without the need to define arbitrary constraints on the design space.

  20. Al2O3:C as a sensitive OSL dosemeter for rapid assessment of environmental photon dose rates

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Agersnap Larsen, N.; Markey, B.G.

    1997-01-01

    The use of Al2O3:C single crystals as optically stimulated luminescence (OSL) dosemeters for rapid assessment of the environmental photon dose rate is proposed. It is shown that Al2O3:C possesses higher OSL sensitivity than TL sensitivity. In TL measurements thermal quenching is a major problem...... and the energy response (equal to that of quartz) make Al2O3:C ideal for measuring the environmental dose rates in connection with luminescence dating and retrospective dosimetry using natural materials and ceramics. (C) 1997 Elsevier Science Ltd....

  1. Simulation Framework for Rapid Entry, Descent, and Landing (EDL) Analysis, Phase 2 Results

    Science.gov (United States)

    Murri, Daniel G.

    2011-01-01

    The NASA Engineering and Safety Center (NESC) was requested to establish the Simulation Framework for Rapid Entry, Descent, and Landing (EDL) Analysis assessment, which involved development of an enhanced simulation architecture using the Program to Optimize Simulated Trajectories II simulation tool. The assessment was requested to enhance the capability of the Agency to provide rapid evaluation of EDL characteristics in systems analysis studies, preliminary design, mission development and execution, and time-critical assessments. Many of the new simulation framework capabilities were developed to support the Agency EDL-Systems Analysis (SA) team that is conducting studies of the technologies and architectures that are required to enable human and higher mass robotic missions to Mars. The findings, observations, and recommendations from the NESC are provided in this report.

  2. Higher sweating rate and skin blood flow during the luteal phase of the menstrual cycle.

    Science.gov (United States)

    Lee, Haneul; Petrofsky, Jerrold; Shah, Nirali; Awali, Abdulaziz; Shah, Karan; Alotaibi, Mohammed; Yim, JongEun

    2014-10-01

    Evaporation by sweating is the most effective way to remove heat from the body. Sweat rates increase under both local and whole-body heat stress. Men and women differ in how they respond to heat, because sexual steroids alter resting body core temperature and the threshold for sweating and skin blood flow (SBF) during heating. The purpose of the present study was to compare local sweat rates and cutaneous vasodilatation during heat exposure in women with a regular menstrual cycle. The cutaneous vasodilatation was judged by measuring the SBF. Eight female and nine male subjects participated in this study, and their age range was 24-29 years. Female subjects were tested twice throughout one full menstrual cycle: once during the middle follicular phases and once during the luteal phase. Subjects remained in a temperature-regulated room at 41°C and 21% of relative humidity for 40 minutes. Sweat rate was recorded from the forehead, forearm, and thigh, and skin temperature and SBF were measured on the thigh and forehead. We found that the sweating rate and SBF were greater in the luteal phase compared to follicular phase (p0.05). We propose the enhanced sympathetic activity in the luteal phase with a regular menstrual cycle.

  3. Determination of crystal growth rates during rapid solidification of polycrystalline aluminum by nano-scale spatio-temporal resolution in situ transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zweiacker, K., E-mail: Kai@zweiacker.org; Liu, C.; Wiezorek, J. M. K. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 648 Benedum Hall, 3700 OHara Street, Pittsburgh, Pennsylvania 15261 (United States); McKeown, J. T.; LaGrange, T.; Reed, B. W.; Campbell, G. H. [Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States)

    2016-08-07

    In situ investigations of rapid solidification in polycrystalline Al thin films were conducted using nano-scale spatio-temporal resolution dynamic transmission electron microscopy. Differences in crystal growth rates and asymmetries in melt pool development were observed as the heat extraction geometry was varied by controlling the proximity of the laser-pulse irradiation and the associated induced melt pools to the edge of the transmission electron microscopy support grid, which acts as a large heat sink. Experimental parameters have been established to maximize the reproducibility of the material response to the laser-pulse-related heating and to ensure that observations of the dynamical behavior of the metal are free from artifacts, leading to accurate interpretations and quantifiable measurements with improved precision. Interface migration rate measurements revealed solidification velocities that increased consistently from ∼1.3 m s{sup −1} to ∼2.5 m s{sup −1} during the rapid solidification process of the Al thin films. Under the influence of an additional large heat sink, increased crystal growth rates as high as 3.3 m s{sup −1} have been measured. The in situ experiments also provided evidence for development of a partially melted, two-phase region prior to the onset of rapid solidification facilitated crystal growth. Using the experimental observations and associated measurements as benchmarks, finite-element modeling based calculations of the melt pool evolution after pulsed laser irradiation have been performed to obtain estimates of the temperature evolution in the thin films.

  4. Rapid and noncontact photoacoustic tomography imaging system using an interferometer with high-speed phase modulation technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jun [School of Physics and Telecom Engineering, South China Normal University, Guangzhou 510006 (China); Tang, Zhilie; Wu, Yongbo [School of Physics and Telecom Engineering, South China Normal University, Guangzhou 510006 (China); GuangDong Province Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, IMOT, Guangzhou 510006 (China); Wang, Yi [School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China)

    2015-04-15

    We designed, fabricated, and tested a rapid and noncontact photoacoustic tomography (PAT) imaging system using a low-coherence interferometer with high-speed phase modulation technique. Such a rapid and noncontact probing system can greatly decrease the time of imaging. The proposed PAT imaging system is experimentally verified by capturing images of a simulated tissue sample and the blood vessels within the ear flap of a mouse (pinna) in vivo. The axial and lateral resolutions of the system are evaluated at 45 and ∼15 μm, respectively. The imaging depth of the system is 1 mm in a special phantom. Our results show that the proposed system opens a promising way to realize noncontact, real-time PAT.

  5. A rapid method of monitoring the acute phase response in a rat model

    African Journals Online (AJOL)

    collectively as the acute phase response (APR), take place. This response ... The blood samples (in Eppendorf tubes) were chilled on ice ... MG in the samples. The latter were then corrected for a sample volume of 200 JJI and the weights of MG in the two spiked samples recovered were calculated from their difference from ...

  6. Rapid amplitude-phase reconstruction of femtosecond pulses from intensity autocorrelation and spectrum

    NARCIS (Netherlands)

    Baltuška, Andrius; Pugžlys, Audrius; Pshenichnikov, Maxim S.; Wiersma, Douwe A.

    1999-01-01

    The retrieval of time-dependent intensity and phase of femtosecond laser pulses is a long standing problem. To date, frequency-resolved optical gating (FROG) is probably the most trustworthy pulse measurement method. However, it requires a substantial experimental and numerical involvement. This

  7. Rapid and convenient semi-automated microwave-assisted solid-phase synthesis of arylopeptoids

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Ewald; Boccia, Marcello Massimo; Nielsen, John

    2014-01-01

    A facile and expedient route to the synthesis of arylopeptoid oligomers (N-alkylated aminomethyl benz-amides) using semi-automated microwave-assisted solid-phase synthesis is presented. The synthesis was optimized for the incorporation of side chains derived from sterically hindered or unreactive...

  8. Rapid variations in fluid chemistry constrain hydrothermal phase separation at the Main Endeavour Field

    Science.gov (United States)

    Love, Brooke; Lilley, Marvin; Butterfield, David; Olson, Eric; Larson, Benjamin

    2017-02-01

    Previous work at the Main Endeavour Field (MEF) has shown that chloride concentration in high-temperature vent fluids has not exceeded 510 mmol/kg (94% of seawater), which is consistent with brine condensation and loss at depth, followed by upward flow of a vapor phase toward the seafloor. Magmatic and seismic events have been shown to affect fluid temperature and composition and these effects help narrow the possibilities for sub-surface processes. However, chloride-temperature data alone are insufficient to determine details of phase separation in the upflow zone. Here we use variation in chloride and gas content in a set of fluid samples collected over several days from one sulfide chimney structure in the MEF to constrain processes of mixing and phase separation. The combination of gas (primarily magmatic CO2 and seawater-derived Ar) and chloride data, indicate that neither variation in the amount of brine lost, nor mixing of the vapor phase produced at depth with variable quantities of (i) brine or (ii) altered gas rich seawater that has not undergone phase separation, can explain the co-variation of gas and chloride content. The gas-chloride data require additional phase separation of the ascending vapor-like fluid. Mixing and gas partitioning calculations show that near-critical temperature and pressure conditions can produce the fluid compositions observed at Sully vent as a vapor-liquid conjugate pair or as vapor-liquid pair with some remixing, and that the gas partition coefficients implied agree with theoretically predicted values.Plain Language SummaryWhen the chemistry of fluids from deep sea hot springs changes over a short time span, it allows us to narrow down the conditions and processes that created those fluids. This gives us a better idea what is happening under the seafloor where the water is interacting with hot rocks and minerals, boiling, and taking on the character it will have when it emerges at the seafloor. Gasses like argon can be

  9. Slow vs rapid delivery rate shock wave lithotripsy for pediatric renal urolithiasis: a prospective randomized study.

    Science.gov (United States)

    Salem, Hosni Khairy; Fathy, Hesham; Elfayoumy, Hanny; Aly, Hussein; Ghonium, Ahmed; Mohsen, Mostafa A; Hegazy, Abd El Rahim

    2014-05-01

    We compared slow vs fast shock wave frequency rates in disintegration of pediatric renal stones less than 20 mm. Our study included 60 children with solitary 10 to 20 mm radiopaque renal stones treated with shock wave lithotripsy. Patients were prospectively randomized into 2 groups, ie those undergoing lithotripsy at a rate of 80 shock waves per minute (group 1, 30 patients) and those undergoing lithotripsy at a rate of 120 shock waves per minute (group 2, 30 patients). The 2 groups were compared in terms of treatment success, anesthesia time, secondary procedures and efficiency quotient. Stone clearance rate was significantly higher in group 1 (90%) than in group 2 (73.3%, p = 0.025). A total of 18 patients in group 1 (60%) were rendered stone-free after 1 session, 8 required 2 sessions and 1 needed 3 sessions, while shock wave lithotripsy failed in 3 patients. By comparison, 8 patients (26.6%) in group 2 were rendered stone-free after 1 session, 10 (33.3%) required 2 sessions and 4 (13.3%) needed 3 sessions to become stone-free. Mean general anesthesia time was significantly longer in group 1 (p = 0.041). Postoperatively 2 patients in group 1 and 4 in group 2 suffered low grade fever (Clavien grade II). Significantly more secondary procedures (percutaneous nephrolithotomy, repeat shock wave lithotripsy) were required in group 2 (p = 0.005). The predominant stone analysis was calcium oxalate dihydrate in both groups. Efficiency quotient was 0.5869 and 0.3437 for group 1 and group 2, respectively (p = 0.0247). In children with renal stones slow delivery rates of shock wave lithotripsy have better results regarding stone clearance than fast delivery rates. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  10. Measuring the Transition Rates of Coalescence Events during Double Phase Separation in Microgravity

    Directory of Open Access Journals (Sweden)

    Ana Oprisan

    2017-07-01

    Full Text Available Phase transition is a ubiquitous phenomenon in nature, science and technology. In general, the phase separation from a homogeneous phase depends on the depth of the temperature quench into the two-phase region. Earth’s gravity masks the details of phase separation phenomena, which is why experiments were performed under weightlessness. Under such conditions, the pure fluid sulphur hexafluoride (SF 6 near its critical point also benefits from the universality of phase separation behavior and critical slowing down of dynamics. Initially, the fluid was slightly below its critical temperature with the liquid matrix separated from the vapor phase. A 0.2 mK temperature quench further cooled down the fluid and produced a double phase separation with liquid droplets inside the vapor phase and vapor bubbles inside the liquid matrix, respectively. The liquid droplets and the vapor bubbles respective distributions were well fitted by a lognormal function. The evolution of discrete bins of different radii allowed the derivation of the transition rates for coalescence processes. Based on the largest transition rates, two main coalescence mechanisms were identified: (1 asymmetric coalescences between one small droplet of about 20 μ m and a wide range of larger droplets; and (2 symmetric coalescences between droplets of large and similar radii. Both mechanisms lead to a continuous decline of the fraction of small radii droplets and an increase in the fraction of the large radii droplets. Similar coalescence mechanisms were observed for vapor bubbles. However, the mean radii of liquid droplets exhibits a t 1 / 3 evolution, whereas the mean radii of the vapor bubbles exhibit a t 1 / 2 evolution.

  11. Measuring the Transition Rates of Coalescence Events during Double Phase Separation in Microgravity.

    Science.gov (United States)

    Oprisan, Ana; Garrabos, Yves; Lecoutre, Carole; Beysens, Daniel

    2017-07-06

    Phase transition is a ubiquitous phenomenon in nature, science and technology. In general, the phase separation from a homogeneous phase depends on the depth of the temperature quench into the two-phase region. Earth's gravity masks the details of phase separation phenomena, which is why experiments were performed under weightlessness. Under such conditions, the pure fluid sulphur hexafluoride (SF 6 ) near its critical point also benefits from the universality of phase separation behavior and critical slowing down of dynamics. Initially, the fluid was slightly below its critical temperature with the liquid matrix separated from the vapor phase. A 0.2 mK temperature quench further cooled down the fluid and produced a double phase separation with liquid droplets inside the vapor phase and vapor bubbles inside the liquid matrix, respectively. The liquid droplets and the vapor bubbles respective distributions were well fitted by a lognormal function. The evolution of discrete bins of different radii allowed the derivation of the transition rates for coalescence processes. Based on the largest transition rates, two main coalescence mechanisms were identified: (1) asymmetric coalescences between one small droplet of about 20 μ m and a wide range of larger droplets; and (2) symmetric coalescences between droplets of large and similar radii. Both mechanisms lead to a continuous decline of the fraction of small radii droplets and an increase in the fraction of the large radii droplets. Similar coalescence mechanisms were observed for vapor bubbles. However, the mean radii of liquid droplets exhibits a t 1 / 3 evolution, whereas the mean radii of the vapor bubbles exhibit a t 1 / 2 evolution.

  12. Electrode Probes for the Rapid Assay of Seafood Toxicants. Phase 1

    Science.gov (United States)

    1990-03-01

    probes can provide rapid analyte determination in complex samples such as blood. For instance, diabetics can now use an electrochemical enzyme...control was incorporated in which there was no aOA/POD; 50 A1 PBS-Tween and 50 p1 of MeOH (45% in aquo ) were incubated for 30 minutes as above. The... complex samples such as fish tissue, urine and blood. 18 Referenoes (1) The Merck Index, loth Edition, M. Windholz, S. Budavari, R.F. Blumetti and E.S

  13. Development of a Rapid Cell-free Method for Cytotoxicity Assessment of Vapor Phase of Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Cahours X

    2014-12-01

    Full Text Available Currently, several in vitro tests are widely used to measure toxicological properties of mainstream smoke (Neutral Red Uptake Assay, Micronucleus assay, Ames Test. These tests are necessary to assess cytotoxicity, genotoxicity, and mutagenicity, but are time consuming. This is essentially due to the preparation and the handling of cells. It is difficult to use these in vitro tests as screening method for product testing and development. For a better assessment of the cytotoxicity of the vapor phase, a rapid cell-free method has been developed. This paper describes a capillary electrophoresis cell-free method, based on the depletion of an anti-oxidant L-gamma-glutamyl-L-cysteinylglycine (GSH, applied to an aliquot of vapor phase phosphate buffered saline (PBS-trapped cigarette smoke (as recommended for in vitro testing. The correlation between this method and the survival/viability test (Neutral Red cytotoxicity is excellent (coefficient of correlation (r = 0.99.

  14. A rapid and rational approach to generating isomorphous heavy-atom phasing derivatives.

    Science.gov (United States)

    Lu, Jinghua; Sun, Peter D

    2014-09-01

    In attempts to replace the conventional trial-and-error heavy-atom derivative search method with a rational approach, we previously defined heavy metal compound reactivity against peptide ligands. Here, we assembled a composite pH- and buffer-dependent peptide reactivity profile for each heavy metal compound to guide rational heavy-atom derivative search. When knowledge of the best-reacting heavy-atom compound is combined with mass spectrometry assisted derivatization, and with a quick-soak method to optimize phasing, it is likely that the traditional heavy-atom compounds could meet the demand of modern high-throughput X-ray crystallography. As an example, we applied this rational heavy-atom phasing approach to determine a previously unknown mouse serum amyloid A2 crystal structure. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  15. Quatification of Primary Phase Undercooling of Rapidly Solidified Droplets with 3D Microtomography

    Science.gov (United States)

    Ilbagi, A.; Khatibi, P. Delshad; Henein, H.; Gandin, Ch. A.; Herlach, D. M.

    Powders of different compositions of Al-Cu alloys were atomized in helium and nitrogen and the microstructure of the atomized droplets was examined using X-ray micro-tomography. A method was developed to remove X-ray artifacts and background noise from the particles images. The method developed involves creating a clean mask file using MATLAB image toolbox, followed by applying the mask file to the original image to achieve clean images for the particle of interest. Separate features of interest in the droplets, such as region of initial growth and primary dendrites, were investigated at the various stages of solidification. The data is used to estimate the primary phase undercooling of the droplets, which will be used in a solidification model as an input to estimate the phase fractions. The results will then be compared with the experimental results.

  16. Rapid purification of diastereoisomers from Piper kadsura using supercritical fluid chromatography with chiral stationary phases.

    Science.gov (United States)

    Xin, Huaxia; Dai, Zhuoshun; Cai, Jianfeng; Ke, Yanxiong; Shi, Hui; Fu, Qing; Jin, Yu; Liang, Xinmiao

    2017-08-04

    Supercritical fluid chromatography (SFC) with chiral stationary phases (CSPs) is an advanced solution for the separation of achiral compounds in Piper kadsura. Analogues and stereoisomers are abundant in natural products, but there are obstacles in separation using conventional method. In this paper, four lignan diastereoisomers, (-)-Galbelgin, (-)-Ganschisandrin, Galgravin and (-)-Veraguensin, from Piper kadsura were separated and purified by chiral SFC. Purification strategy was designed, considering of the compound enrichment, sample purity and purification throughput. Two-step achiral purification method on chiral preparative columns with stacked automated injections was developed. Unconventional mobile phase modifier dichloromethane (DCM) was applied to improve the sample solubility. Four diastereoisomers was prepared at the respective weight of 103.1mg, 10.0mg, 152.3mg and 178.6mg from 710mg extract with the purity of greater than 98%. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Investigations of effect of phase change mass transfer rate on cavitation process with homogeneous relaxation model

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhixia; Zhang, Liang; Saha, Kaushik; Som, Sibendu; Duan, Lian; Wang, Qian

    2017-12-01

    The super high fuel injection pressure and micro size of nozzle orifice has been an important development trend for the fuel injection system. Accordingly, cavitation transient process, fuel compressibility, amount of noncondensable gas in the fuel and cavitation erosion have attracted more attention. Based on the fact of cavitation in itself is a kind of thermodynamic phase change process, this paper takes the perspective of the cavitation phase change mass transfer process to analyze above mentioned phenomenon. The two-phase cavitating turbulent flow simulations with VOF approach coupled with HRM cavitation model and U-RANS of standard k-ε turbulence model were performed for investigations of cavitation phase change mass transfer process. It is concluded the mass transfer time scale coefficient in the Homogenous Relaxation Model (HRM) representing mass transfer rate should tend to be as small as possible in a condition that ensured the solver stable. At very fast mass transfer rate, the phase change occurs at very thin interface between liquid and vapor phase and condensation occurs more focused and then will contribute predictably to a more serious cavitation erosion. Both the initial non-condensable gas in fuel and the fuel compressibility can accelerate the cavitation mass transfer process.

  18. Sinterable Ceramic Powders from Laser Heated Gas Phase Reactions and Rapidly Solidified Ceramic Materials.

    Science.gov (United States)

    1984-07-01

    Gattuso, T. R., Meunier, M., Adler, D., and Haggerty, J. S., "IR Laser- Induced Deposition of Silicon Thin Films ", to be published in the Proceedings of...and Thin Films by Laser Induced Gas Phase Reactions", presented at the Nineteenth University Conference on Ceramic Science, Emergent Process Methods... Silicon Carbonitrides from Monomeric Organosilicon Precursors". To be presented at the 1983 Annual Meeting of the American Ceramic Society, April 1983

  19. Rapid amplitude-phase reconstruction of femtosecond pulses from intensity autocorrelation and spectrum

    OpenAIRE

    Baltuška, Andrius; Pugžlys, Audrius; Pshenichnikov, Maxim S.; Wiersma, Douwe A.

    1999-01-01

    The retrieval of time-dependent intensity and phase of femtosecond laser pulses is a long standing problem. To date, frequency-resolved optical gating (FROG) is probably the most trustworthy pulse measurement method. However, it requires a substantial experimental and numerical involvement. This motivates the quest for other simpler high-fidelity pulse measuring techniques. We present a new method of deciphering the pulse structure from the intensity autocorrelation trace and the intensity sp...

  20. Cage Culture Turbidostat: a Device for Rapid Determination of Algal Growth Rate

    OpenAIRE

    Skipnes, Olav; Eide, Ingvar; Jensen, Arne

    1980-01-01

    The present cage culture turbidostat consists of a growth chamber and a control unit. The microorganisms (photoautotrophic algae) are kept in the growth chamber by porous membranes (pore size 1 to 3 μm) which retain the algae but allow efficient exchange of the growth medium. Flow rate and composition of the medium can therefore be varied independently of algal population density. A reciprocating pumping mode of the medium is introduced to obtain more gentle clearance of membranes than that p...

  1. EFFECT OF MECHANICAL PROPERTIES OF MARTENSITE AND LOADING RATE ON DUAL PHASE STEELS

    Directory of Open Access Journals (Sweden)

    Ali BAYRAM

    1998-03-01

    Full Text Available In this study, steel sheet materials were used in order to obtain dual-phase steel. Specimens for this purpose have been annealed in ferrite + astatine regions at the temperatures of 740, 760, 800 and 820 °C. The specimens were annealed at the different temperatures with corresponding times 20, 40 and 60 minutes and quenched into water. As a result of this dual-phase steels at different ferrite + martensite ratio were produced. Sheet specimens were tested at the range of loading rates of 10, 50 and 259 mm/min. Strength properties of dual-phase steels were investigated depending on annealing temperature, ratio of martensite and loading rate.

  2. Rapid Heartbeat, But Dry Palms: Reactions of Heart Rate and Skin Conductance Levels to Social Rejection

    Directory of Open Access Journals (Sweden)

    Benjamin eIffland

    2014-08-01

    Full Text Available Background: Social rejection elicits negative mood, emotional distress and neural activity in networks that are associated with physical pain. However, studies assessing physiological reactions to social rejection are rare and results of these studies were found to be ambiguous. Therefore, the present study aimed to examine and specify physiological effects of social rejection.Methods: Participants (N = 50 were assigned to either a social exclusion or inclusion condition of a virtual ball-tossing game (Cyberball. Immediate and delayed physiological (skin conductance level and heart rate reactions were recorded. In addition, subjects reported levels of affect, emotional states and fundamental needs.Results: Subjects who were socially rejected showed increased heart rates. However, social rejection had no effect on subjects’ skin conductance levels. Both conditions showed heightened arousal on this measurement. Furthermore, psychological consequences of social rejection indicated the validity of the paradigm.Conclusions: Our results reveal that social rejection evokes an immediate physiological reaction. Accelerated heart rates indicate that behavior activation rather than inhibition is associated with socially threatening events. In addition, results revealed gender-specific response patterns suggesting that sample characteristics such as differences in gender may account for ambiguous findings of physiological reactions to social rejection.

  3. Rapid heartbeat, but dry palms: reactions of heart rate and skin conductance levels to social rejection.

    Science.gov (United States)

    Iffland, Benjamin; Sansen, Lisa M; Catani, Claudia; Neuner, Frank

    2014-01-01

    Social rejection elicits negative mood, emotional distress, and neural activity in networks that are associated with physical pain. However, studies assessing physiological reactions to social rejection are rare and results of these studies were found to be ambiguous. Therefore, the present study aimed to examine and specify physiological effects of social rejection. Participants (n = 50) were assigned to either a social exclusion or inclusion condition of a virtual ball-tossing game (Cyberball). Immediate and delayed physiological [skin conductance level (SCL) and heart rate] reactions were recorded. In addition, subjects reported levels of affect, emotional states, and fundamental needs. Subjects who were socially rejected showed increased heart rates. However, social rejection had no effect on subjects' SCLs. Both conditions showed heightened arousal on this measurement. Furthermore, psychological consequences of social rejection indicated the validity of the paradigm. Our results reveal that social rejection evokes an immediate physiological reaction. Accelerated heart rates indicate that behavior activation rather than inhibition is associated with socially threatening events. In addition, results revealed gender-specific response patterns suggesting that sample characteristics such as differences in gender may account for ambiguous findings of physiological reactions to social rejection.

  4. Multiband carrierless amplitude/phase modulation for ultra-wideband high data rate wireless communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Altabas, Jose A.

    2016-01-01

    We report on the first experimental demonstration of carrierless amplitude/phase modulation in a flexible multiband approach for ultrawideband high-data-rate wireless communications. An effective bitrate of 2 GB/s is achieved while complying with the restrictions on the effective radiated power e...

  5. Hardening in Two-Phase Materials. II. Plastic Strain and Mean Stress Hardening Rate

    DEFF Research Database (Denmark)

    Lilholt, Hans

    1977-01-01

    The strain parameters which are relevant in a tensile experiment, are analysed and related to the geometry of deformation and to the mean stress of two-phase materials. The hardening rate of the mean stress with respect to plastic strain is found to be useful in comparison between experiments...

  6. A portable microfluidic system for rapid measurement of the erythrocyte sedimentation rate.

    Science.gov (United States)

    Isiksacan, Ziya; Erel, Ozcan; Elbuken, Caglar

    2016-11-29

    The erythrocyte sedimentation rate (ESR) is a frequently used 30 min or 60 min clinical test for screening of several inflammatory conditions, infections, trauma, and malignant diseases, as well as non-inflammatory conditions including prostate cancer and stroke. Erythrocyte aggregation (EA) is a physiological process where erythrocytes form face-to-face linear structures, called rouleaux, at stasis or low shear rates. In this work, we proposed a method for ESR measurement from EA. We developed a microfluidic opto-electro-mechanical system, using which we experimentally showed a significant correlation (R(2) = 0.86) between ESR and EA. The microfluidic system was shown to measure ESR from EA using fingerprick blood in 2 min. 40 μl of whole blood is filled in a disposable polycarbonate cartridge which is illuminated with a near infrared emitting diode. Erythrocytes were disaggregated under the effect of a mechanical shear force using a solenoid pinch valve. Following complete disaggregation, transmitted light through the cartridge was measured using a photodetector for 1.5 min. The intensity level is at its lowest at complete disaggregation and highest at complete aggregation. We calculated ESR from the transmitted signal profile. We also developed another microfluidic cartridge specifically for monitoring the EA process in real-time during ESR measurement. The presented system is suitable for ultrafast, low-cost, and low-sample volume measurement of ESR at the point-of-care.

  7. Experimental evidence that ooid size reflects a dynamic equilibrium between rapid precipitation and abrasion rates

    Science.gov (United States)

    Trower, Elizabeth J.; Lamb, Michael P.; Fischer, Woodward W.

    2017-06-01

    Ooids are enigmatic concentrically coated carbonate sand grains that reflect a fundamental mode of carbonate sedimentation and inorganic product of the carbon cycle-trends in their composition and size are thought to record changes in seawater chemistry over Earth history. Substantial debate persists concerning the roles of physical, chemical, and microbial processes in their growth, including whether carbonate precipitation on ooid surfaces is driven by seawater chemistry or microbial activity, and what role-if any-sediment transport and abrasion play. To test these ideas, we developed an approach to study ooids in the laboratory employing sediment transport stages and seawater chemistry similar to natural environments. Ooid abrasion and precipitation rates in the experiments were four orders of magnitude faster than radiocarbon net growth rates of natural ooids, implying that ooids approach a stable size representing a dynamic equilibrium between precipitation and abrasion. Results demonstrate that the physical environment is as important as seawater chemistry in controlling ooid growth and, more generally, that sediment transport plays a significant role in chemical sedimentary systems.

  8. A simple and rapid method for standard preparation of gas phase extract of cigarette smoke.

    Directory of Open Access Journals (Sweden)

    Tsunehito Higashi

    Full Text Available Cigarette smoke consists of tar and gas phase: the latter is toxicologically important because it can pass through lung alveolar epithelium to enter the circulation. Here we attempt to establish a standard method for preparation of gas phase extract of cigarette smoke (CSE. CSE was prepared by continuously sucking cigarette smoke through a Cambridge filter to remove tar, followed by bubbling it into phosphate-buffered saline (PBS. An increase in dry weight of the filter was defined as tar weight. Characteristically, concentrations of CSEs were represented as virtual tar concentrations, assuming that tar on the filter was dissolved in PBS. CSEs prepared from smaller numbers of cigarettes (original tar concentrations ≤ 15 mg/ml showed similar concentration-response curves for cytotoxicity versus virtual tar concentrations, but with CSEs from larger numbers (tar ≥ 20 mg/ml, the curves were shifted rightward. Accordingly, the cytotoxic activity was detected in PBS of the second reservoir downstream of the first one with larger numbers of cigarettes. CSEs prepared from various cigarette brands showed comparable concentration-response curves for cytotoxicity. Two types of CSEs prepared by continuous and puff smoking protocols were similar regarding concentration-response curves for cytotoxicity, pharmacology of their cytotoxicity, and concentrations of cytotoxic compounds. These data show that concentrations of CSEs expressed by virtual tar concentrations can be a reference value to normalize their cytotoxicity, irrespective of numbers of combusted cigarettes, cigarette brands and smoking protocols, if original tar concentrations are ≤15 mg/ml.

  9. Rapid nanostructuration of polymer colloid surfaces by nonsolvent induced phase separation.

    Science.gov (United States)

    Zheng, Lu; Ma, Zhaohui; Li, Zhanping; Yan, Qingfeng

    2015-03-01

    We have designed an effective strategy for producing nanostructures on the polymer colloid surfaces within few minutes. The poly(N-vinylpyrrolidone) (PVP)-stabilized polystyrene colloid latex dispersed in ethanol was exposed to a nonsolvent medium of PVP and nanometric droplets formed on the polymer colloid surfaces within few minutes. Surface wettability of the polymer colloids with nanoprotrusions experienced a significant change as compared with the smooth polymer colloids. The formation mechanism was ascribed to the precipitation of PVP phase due to the nonsolvent induced phase separation. To further confirm the proposed mechanism, the material components included in the polymer colloid lattices before the nanostructuration process and surface compositions on the nanostructured polymer colloid surfaces were characterized using gel permeation chromatography (GPC) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) respectively. This new strategy provides an alternative and promising method for patterning curved polymer surfaces. The polymer colloids with different surface textures would be ideal for use as model systems in biomedical research such as targets in phagocytosis and platforms of drug delivery. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. A Simple and Rapid Method for Standard Preparation of Gas Phase Extract of Cigarette Smoke

    Science.gov (United States)

    Higashi, Tsunehito; Mai, Yosuke; Noya, Yoichi; Horinouchi, Takahiro; Terada, Koji; Hoshi, Akimasa; Nepal, Prabha; Harada, Takuya; Horiguchi, Mika; Hatate, Chizuru; Kuge, Yuji; Miwa, Soichi

    2014-01-01

    Cigarette smoke consists of tar and gas phase: the latter is toxicologically important because it can pass through lung alveolar epithelium to enter the circulation. Here we attempt to establish a standard method for preparation of gas phase extract of cigarette smoke (CSE). CSE was prepared by continuously sucking cigarette smoke through a Cambridge filter to remove tar, followed by bubbling it into phosphate-buffered saline (PBS). An increase in dry weight of the filter was defined as tar weight. Characteristically, concentrations of CSEs were represented as virtual tar concentrations, assuming that tar on the filter was dissolved in PBS. CSEs prepared from smaller numbers of cigarettes (original tar concentrations ≤15 mg/ml) showed similar concentration-response curves for cytotoxicity versus virtual tar concentrations, but with CSEs from larger numbers (tar ≥20 mg/ml), the curves were shifted rightward. Accordingly, the cytotoxic activity was detected in PBS of the second reservoir downstream of the first one with larger numbers of cigarettes. CSEs prepared from various cigarette brands showed comparable concentration-response curves for cytotoxicity. Two types of CSEs prepared by continuous and puff smoking protocols were similar regarding concentration-response curves for cytotoxicity, pharmacology of their cytotoxicity, and concentrations of cytotoxic compounds. These data show that concentrations of CSEs expressed by virtual tar concentrations can be a reference value to normalize their cytotoxicity, irrespective of numbers of combusted cigarettes, cigarette brands and smoking protocols, if original tar concentrations are ≤15 mg/ml. PMID:25229830

  11. Rapid growth reduces cold resistance: evidence from latitudinal variation in growth rate, cold resistance and stress proteins.

    Directory of Open Access Journals (Sweden)

    Robby Stoks

    Full Text Available BACKGROUND: Physiological costs of rapid growth may contribute to the observation that organisms typically grow at submaximal rates. Although, it has been hypothesized that faster growing individuals would do worse in dealing with suboptimal temperatures, this type of cost has never been explored empirically. Furthermore, the mechanistic basis of the physiological costs of rapid growth is largely unexplored. METHODOLOGY/PRINCIPAL FINDING: Larvae of the damselfly Ischnura elegans from two univoltine northern and two multivoltine southern populations were reared at three temperatures and after emergence given a cold shock. Cold resistance, measured by chill coma recovery times in the adult stage, was lower in the southern populations. The faster larval growth rates in the southern populations contributed to this latitudinal pattern in cold resistance. In accordance with their assumed role in cold resistance, Hsp70 levels were lower in the southern populations, and faster growing larvae had lower Hsp70 levels. Yet, individual variation in Hsp70 levels did not explain variation in cold resistance. CONCLUSIONS/SIGNIFICANCE: WE PROVIDE EVIDENCE FOR A NOVEL COST OF RAPID GROWTH: reduced cold resistance. Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates. This also illustrates that stressors imposed in the larval stage may carry over and shape fitness in the adult stage and highlights the importance of physiological costs in the evolution of life-histories at macro-scales.

  12. A multiplexed microfluidic toolbox for the rapid optimization of affinity-driven partition in aqueous two phase systems.

    Science.gov (United States)

    Bras, Eduardo J S; Soares, Ruben R G; Azevedo, Ana M; Fernandes, Pedro; Arévalo-Rodríguez, Miguel; Chu, Virginia; Conde, João P; Aires-Barros, M Raquel

    2017-09-15

    Antibodies and other protein products such as interferons and cytokines are biopharmaceuticals of critical importance which, in order to be safely administered, have to be thoroughly purified in a cost effective and efficient manner. The use of aqueous two-phase extraction (ATPE) is a viable option for this purification, but these systems are difficult to model and optimization procedures require lengthy and expensive screening processes. Here, a methodology for the rapid screening of antibody extraction conditions using a microfluidic channel-based toolbox is presented. A first microfluidic structure allows a simple negative-pressure driven rapid screening of up to 8 extraction conditions simultaneously, using less than 20μL of each phase-forming solution per experiment, while a second microfluidic structure allows the integration of multi-step extraction protocols based on the results obtained with the first device. In this paper, this microfluidic toolbox was used to demonstrate the potential of LYTAG fusion proteins used as affinity tags to optimize the partitioning of antibodies in ATPE processes, where a maximum partition coefficient (K) of 9.2 in a PEG 3350/phosphate system was obtained for the antibody extraction in the presence of the LYTAG-Z dual ligand. This represents an increase of approx. 3.7 fold when compared with the same conditions without the affinity molecule (K=2.5). Overall, this miniaturized and versatile approach allowed the rapid optimization of molecule partition followed by a proof-of-concept demonstration of an integrated back extraction procedure, both of which are critical procedures towards obtaining high purity biopharmaceuticals using ATPE. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. POSSIBLE RAPID STRAIN ACCUMULATION RATES NEAR CALI, COLOMBIA, DETERMINED FROM GPS MEASUREMENTS (1996-2003

    Directory of Open Access Journals (Sweden)

    Trenkamp Robert

    2004-06-01

    Full Text Available Global Positioning System (GPS data from southern Central America and northwestern South America collected between 1991 and 1998 reveal wide plate margin deformation along a 1400 km length of the North Andes. Also associated with the oblique subduction of the Nazca plate at the Colombia-Ecuador trench is the 'escape' of the North Andes block (NAB. The NAB is delineated by the Bocono-East Andean fault systems and the Dolores Guayaquil Megasheare to the east, the South Caribbean deformed belt on the north and the Colombia-Ecuador trench and Panama on the west. Within the NAB many damaging crustal earthquakes have occurred which is most recently exemplified on January 25, 1999 (Mw = 6.1 Armenia earthquake. Preliminary analysis of recent occupations (2003 GEORED GPS of several previously observed (1996-2001 GPS sites suggest shear strain accumulation rates in the Cauca valley near Cali of approximately 2.1 x 10-7 yr-1 and 1.6 x 10-7 yr-1. These strain rates are measured within 2 Delaunay triangles with common vertices at Cali and Restrepo, which encompass areas, located north and west of Cali.Seismicity has been monitored in the Cauca Valley for the last 17 years by the "Observatorio Sismológico del Suroccidente" (OSSO since 1987 and by the Red Sismológica Nacional del INGEOMINAS since 1993. Their catalogs list numerous shallow earthquakes near Cali but nothing larger than magnitude 5. Historically, however, several large earthquakes are associated with the "Falla Cauca Almaguer" in locations both to the south and north of Cali in the Cauca valley. Preliminary calculations using the strain rates determined for these Delaunay triangles and a simplified Kostrov formula suggest possible decadal (30 - 90 years recurrence intervals for Mw = 6.0 - 6.3 earthquakes, centenary (90 - 900 years recurrence intervals for Mw = 6.4 - 6.9 earthquakes and millennial (900+ years recurrence intervals for Mw ≥ 7 earthquakes.

  14. Rapid slowing of the atrial fibrillatory rate after administration of AZD7009 predicts conversion of atrial fibrillation

    DEFF Research Database (Denmark)

    Aunes, Maria; Egstrup, Kenneth; Frison, Lars

    2014-01-01

    BACKGROUND: Effects on the atrial fibrillatory rate (AFR) were studied during infusion with the combined potassium and sodium channel blocker AZD7009. METHODS AND RESULTS: Patients with persistent atrial fibrillation (AF) were randomized to AZD7009 or placebo. Thirty-five patients converted to si...... fpm (p=0.02), and at 10 min, -133 vs. -111 fpm (p=0.048). The AFR-SD and the exponential decay decreased. A small left atrial area was the only baseline predictor of conversion to SR. CONCLUSIONS: AZD7009 produced a significantly more rapid decrease of the AFR in converters than in non...

  15. Is the surface oxygen exchange rate linked to bulk ion diffusivity in mixed conducting Ruddlesden-Popper phases?

    Science.gov (United States)

    Tomkiewicz, Alex C; Tamimi, Mazin A; Huq, Ashfia; McIntosh, Steven

    2015-01-01

    The possible link between oxygen surface exchange rate and bulk oxygen anion diffusivity in mixed ionic and electronic conducting oxides is a topic of great interest and debate. While a large body of experimental evidence and theoretical analyses support a link, observed differences between bulk and surface composition of these materials are hard to reconcile with this observation. This is further compounded by potential problems with simultaneous measurement of both parameters. Here we utilize separate techniques, in situ neutron diffraction and pulsed isotopic surface exchange, to examine bulk ion mobility and surface oxygen exchange rates of three Ruddlesden-Popper phases, general form A(n-1)A(2)'B(n)O(3n+1), A(n-1)A(2)'B(n)X(3n+1); LaSrCo(0.5)Fe(0.5)O(4-δ) (n = 1), La(0.3)Sr(2.7)CoFeO(7-δ) (n = 2) and LaSr3Co(1.5)Fe(1.5)O(10-δ) (n = 3). These measurements are complemented by surface composition determination via high sensitivity-low energy ion scattering. We observe a correlation between bulk ion mobility and surface exchange rate between materials. The surface exchange rates vary by more than one order of magnitude with high anion mobility in the bulk of an oxygen vacancy-rich n = 2 Ruddlesden-Popper material correlating with rapid oxygen exchange. This is in contrast with the similar surface exchange rates which we may expect due to similar surface compositions across all three samples. We conclude that experimental limitations lead to inherent convolution of surface and bulk rates, and that surface exchange steps are not likely to be rate limiting in oxygen incorporation.

  16. Live birth rates and safety profile using dydrogesterone for luteal phase support in assisted reproductive techniques.

    Science.gov (United States)

    Nadarajah, Ravichandran; Rajesh, Hemashree; Wong, Ker Yi; Faisal, Fazlin; Yu, Su Ling

    2017-06-01

    Assisted reproductive techniques (ARTs) result in a deficient luteal phase, requiring the administration of intramuscular, intravaginal or oral exogenous progesterone. Dydrogesterone, an oral retroprogesterone with good bioavailability, has been used in assisted reproductive cycles with outcomes that are comparable to those of vaginal or intramuscular progesterone. However, there are limited reviews on its use for luteal phase support in ARTs, in terms of pregnancy outcomes and associated fetal anomalies. This study aimed to review the live birth rates and associated fetal anomalies of women who were given dydrogesterone for luteal phase support in assisted reproductive cycles at a tertiary hospital in Singapore. This retrospective descriptive study included 1,050 women who underwent in vitro fertilisation/intracytoplasmic sperm injection at the Centre for Assisted Reproduction of Singapore General Hospital between 2000 and 2011. The women were given dydrogesterone for luteal phase support. The main outcome measures were rates of pregnancy, live birth, miscarriage and fetal anomalies. The pregnancy and live birth rates were 34.7% and 27.7%, respectively. Among those who achieved pregnancy, 17.0% miscarried, 0.8% had ectopic pregnancies and 0.3% had molar pregnancies. Fetal anomalies were detected in 1.9% of pregnancies, all of which were terminated by choice. Since the outcomes of dydrogesterone are comparable to those of intramuscular and vaginal progesterone, it is a reasonable option to provide luteal phase support for women who are uncomfortable with injections or vaginal insertions. Randomised controlled studies are needed to determine the optimal dosage of dydrogesterone for luteal phase support in ARTs.

  17. Surface modification induced phase transformation and structure variation on the rapidly solidified recast layer of titanium

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Ming-Hung [Department of Mechanical Engineering and Graduate Institute of Mechanical and Precision Engineering, National Kaoshiung University of Applied Sciences, Kaoshiung 807, Taiwan (China); School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Haung, Chiung-Fang [School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Division of Family and Operative Dentistry, Department of Dentistry, Taipei Medical University Hospital, Taipei 110, Taiwan (China); Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei 110, Taiwan (China); Shyu, Shih-Shiun [Department of Dentistry, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan (China); Chou, Yen-Ru [Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei 110, Taiwan (China); Graduate Institute of Biomedical Materials and Tissue Engineering, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Research Center for Biomedical Implants and Microsurgery Devices, Taipei Medical University, Taipei 110, Taiwan (China); Lin, Ming-Hong [Department of Mechanical Engineering and Graduate Institute of Mechanical and Precision Engineering, National Kaoshiung University of Applied Sciences, Kaoshiung 807, Taiwan (China); Peng, Pei-Wen, E-mail: apon@tmu.edu.tw [School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); and others

    2015-08-15

    In this study, neodymium-doped yttrium orthovanadate (Nd:YVO{sub 4}) as a laser source with different scanning speeds was used on biomedical Ti surface. The microstructural and biological properties of laser-modified samples were investigated by means of optical microscope, electron microscope, X-ray diffraction, surface roughness instrument, contact angle and cell cytotoxicity assay. After laser modification, the rough volcano-like recast layer with micro-/nanoporous structure and wave-like recast layer with nanoporous structure were generated on the surfaces of laser-modified samples, respectively. It was also found out that, an α → (α + rutile-TiO{sub 2}) phase transition occurred on the recast layers of laser-modified samples. The Ti surface becomes hydrophilic at a high speed laser scanning. Moreover, the cell cytotoxicity assay demonstrated that laser-modified samples did not influence the cell adhesion and proliferation behaviors of osteoblast (MG-63) cell. The laser with 50 mm/s scanning speed induced formation of rough volcano-like recast layer accompanied with micro-/nanoporous structure, which can promote cell adhesion and proliferation of MG-63 cell on Ti surface. The results indicated that the laser treatment was a potential technology to enhance the biocompatibility for titanium. - Highlights: • Laser induced the formation of recast layer with micro-/nanoporous structure on Ti. • An α → (α + rutile-TiO{sub 2}) phase transition was observed within the recast layer. • The Ti surface becomes hydrophilic at a high speed laser scanning. • Laser-modified samples exhibit good biocompatibility to osteoblast (MG-63) cell.

  18. Advanced powder metallurgy aluminum alloys via rapid solidification technology, phase 2

    Science.gov (United States)

    Ray, Ranjan; Jha, Sunil C.

    1987-01-01

    Marko's rapid solidification technology was applied to processing high strength aluminum alloys. Four classes of alloys, namely, Al-Li based (class 1), 2124 type (class 2), high temperature Al-Fe-Mo (class 3), and PM X7091 type (class 4) alloy, were produced as melt-spun ribbons. The ribbons were pulverized, cold compacted, hot-degassed, and consolidated through single or double stage extrusion. The mechanical properties of all four classes of alloys were measured at room and elevated temperatures and their microstructures were investigated optically and through electron microscopy. The microstructure of class 1 Al-Li-Mg alloy was predominantly unrecrystallized due to Zr addition. Yield strengths to the order of 50 Ksi were obtained, but tensile elongation in most cases remained below 2 percent. The class 2 alloys were modified composition of 2124 aluminum alloy, through addition of 0.6 weight percent Zr and 1 weight percent Ni. Nickel addition gave rise to a fine dispersion of intermetallic particles resisting coarsening during elevated temperature exposure. The class 2 alloy showed good combination of tensile strength and ductility and retained high strength after 1000 hour exposure at 177 C. The class 3 Al-Fe-Mo alloy showed high strength and good ductility both at room and high temperatures. The yield and tensile strength of class 4 alloy exceeded those of the commercial 7075 aluminum alloy.

  19. Computationally rapid method of estimating signal-to-noise ratio for phased array image reconstructions.

    Science.gov (United States)

    Wiens, Curtis N; Kisch, Shawn J; Willig-Onwuachi, Jacob D; McKenzie, Charles A

    2011-10-01

    Measuring signal-to-noise ratio (SNR) for parallel MRI reconstructions is difficult due to spatially dependent noise amplification. Existing approaches for measuring parallel MRI SNR are limited because they are not applicable to all reconstructions, require significant computation time, or rely on repeated image acquisitions. A new SNR estimation approach is proposed, a hybrid of the repeated image acquisitions method detailed in the National Electrical Manufacturers Association (NEMA) standard and the Monte Carlo based pseudo-multiple replica method, in which the difference between images reconstructed from the unaltered acquired data and that same data reconstructed after the addition of calibrated pseudo-noise is used to estimate the noise in the parallel MRI image reconstruction. This new noise estimation method can be used to rapidly compute the pixel-wise SNR of the image generated from any parallel MRI reconstruction of a single acquisition. SNR maps calculated with the new method are validated against existing SNR calculation techniques. Copyright © 2011 Wiley-Liss, Inc.

  20. Rapid phase adjustment of melatonin and core body temperature rhythms following a 6-h advance of the light/dark cycle in the horse

    Directory of Open Access Journals (Sweden)

    Kennedy Erin L

    2007-08-01

    Full Text Available Abstract Background Rapid displacement across multiple time zones results in a conflict between the new cycle of light and dark and the previously entrained program of the internal circadian clock, a phenomenon known as jet lag. In humans, jet lag is often characterized by malaise, appetite loss, fatigue, disturbed sleep and performance deficit, the consequences of which are of particular concern to athletes hoping to perform optimally at an international destination. As a species renowned for its capacity for athletic performance, the consequences of jet lag are also relevant for the horse. However, the duration and severity of jet lag related circadian disruption is presently unknown in this species. We investigated the rates of re-entrainment of serum melatonin and core body temperature (BT rhythms following an abrupt 6-h phase advance of the LD cycle in the horse. Methods Six healthy, 2 yr old mares entrained to a 12 h light/12 h dark (LD 12:12 natural photoperiod were housed in a light-proofed barn under a lighting schedule that mimicked the external LD cycle. Following baseline sampling on Day 0, an advance shift of the LD cycle was accomplished by ending the subsequent dark period 6 h early. Blood sampling for serum melatonin analysis and BT readings were taken at 3-h intervals for 24 h on alternate days for 11 days. Disturbances to the subsequent melatonin and BT 24-h rhythms were assessed using repeated measures ANOVA and analysis of Cosine curve fitting parameters. Results We demonstrate that the equine melatonin rhythm re-entrains rapidly to a 6-h phase advance of an LD12:12 photocycle. The phase shift in melatonin was fully complete on the first day of the new schedule and rhythm phase and waveform were stable thereafter. In comparison, the advance in the BT rhythm was achieved by the third day, however BT rhythm waveform, especially its mesor, was altered for many days following the LD shift. Conclusion Aside from the temperature

  1. Matching time and spatial scales of rapid solidification: dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

    Science.gov (United States)

    Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.; Fattebert, Jean-Luc; McKeown, Joseph T.

    2018-01-01

    A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu–Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid–liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu–Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying from ∼0.1 to ∼0.6 m s‑1. After an ‘incubation’ time, the velocity of the planar solid–liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Finally, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid–liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).

  2. The Microstructure Evolution of Dual-Phase Pipeline Steel with Plastic Deformation at Different Strain Rates

    Science.gov (United States)

    Ji, L. K.; Xu, T.; Zhang, J. M.; Wang, H. T.; Tong, M. X.; Zhu, R. H.; Zhou, G. S.

    2017-07-01

    Tensile properties of the high-deformability dual-phase ferrite-bainite X70 pipeline steel have been investigated at room temperature under the strain rates of 2.5 × 10-5, 1.25 × 10-4, 2.5 × 10-3, and 1.25 × 10-2 s-1. The microstructures at different amount of plastic deformation were examined by using scanning and transmission electron microscopy. Generally, the ductility of typical body-centered cubic steels is reduced when its stain rate increases. However, we observed a different ductility dependence on strain rates in the dual-phase X70 pipeline steel. The uniform elongation (UEL%) and elongation to fracture (EL%) at the strain rate of 2.5 × 10-3 s-1 increase about 54 and 74%, respectively, compared to those at 2.5 × 10-5 s-1. The UEL% and EL% reach to their maximum at the strain rate of 2.5 × 10-3 s-1. This phenomenon was explained by the observed grain structures and dislocation configurations. Whether or not the ductility can be enhanced with increasing strain rates depends on the competition between the homogenization of plastic deformation among the microconstituents (ultra-fine ferrite grains, relatively coarse ferrite grains as well as bainite) and the progress of cracks formed as a consequence of localized inconsistent plastic deformation.

  3. Dynamic analysis of heartbeat rate signals of epileptics using multidimensional phase space reconstruction approach

    Science.gov (United States)

    Su, Zhi-Yuan; Wu, Tzuyin; Yang, Po-Hua; Wang, Yeng-Tseng

    2008-04-01

    The heartbeat rate signal provides an invaluable means of assessing the sympathetic-parasympathetic balance of the human autonomic nervous system and thus represents an ideal diagnostic mechanism for detecting a variety of disorders such as epilepsy, cardiac disease and so forth. The current study analyses the dynamics of the heartbeat rate signal of known epilepsy sufferers in order to obtain a detailed understanding of the heart rate pattern during a seizure event. In the proposed approach, the ECG signals are converted into heartbeat rate signals and the embedology theorem is then used to construct the corresponding multidimensional phase space. The dynamics of the heartbeat rate signal are then analyzed before, during and after an epileptic seizure by examining the maximum Lyapunov exponent and the correlation dimension of the attractors in the reconstructed phase space. In general, the results reveal that the heartbeat rate signal transits from an aperiodic, highly-complex behaviour before an epileptic seizure to a low dimensional chaotic motion during the seizure event. Following the seizure, the signal trajectories return to a highly-complex state, and the complex signal patterns associated with normal physiological conditions reappear.

  4. Association of apneic oxygenation with decreased desaturation rates during rapid sequence intubation by a Chinese emergency medicine service

    Science.gov (United States)

    Mao, Yong; Qin, Zong-He

    2015-01-01

    Rapid and safe airway management has always been of paramount importance in successful management of critically ill and injured patients in the emergency department. The achievement rate of emergency medicine inhabitants in airway management improved enhanced essentially subsequent to finishing anaesthesiology turn. There was a slightly higher rate of quick sequence intubation in the postapneic oxygenation groups (preapneic oxygenation 6.4%; postapneic oxygenation 9.1%). The majority of patients intubated in both groups were men (preapneic oxygenation 72.3%; postapneic oxygenation 63.5%). A higher percentage of patients in the preapneic oxygenation group had a Cormack-Lehane grade III or worse view (23.2% versus 11.8%). Anaesthesiology turns should be considered as an essential component of emergency medicine training programs. A collateral curriculum of this nature should also focus on the acquisition of skills in airway management. PMID:26379959

  5. Rapid, single-phase extraction of glucosylsphingosine from plasma: A universal screening and monitoring tool.

    Science.gov (United States)

    Fuller, Maria; Szer, Jeff; Stark, Samantha; Fletcher, Janice M

    2015-10-23

    Glucosylsphingosine (GluSph) has emerged as a biomarker for the inherited metabolic disorder, Gaucher disease (GD). We developed a simple laboratory test to measure plasma GluSph and show that elevated GluSph is diagnostic for GD as well as informing on disease burden for monitoring patients on treatment. GluSph was measured from a single-phase total lipid extraction of 0.01 mL of plasma by liquid chromatography-electrospray ionisation-tandem mass spectrometry and concentrations extrapolated from a seven point standard curve (0.04 to 20 pmoL). A total of 1464 samples were tested and longitudinal assessment of an additional 20 GD patients. All patients with GD had elevated GluSph compared to unaffected controls and 16 other metabolic disorders. GluSph was also slightly elevated in three patients with Krabbe disease but not at concentrations to confuse a GD diagnosis. GluSph correlated with chitotriosidase in the majority of GD patients on treatment who were informative for this marker. GluSph can be easily measured from 0.01 mL of plasma and is useful as a diagnostic marker for GD with the current platform suited to high-throughput screening. It outperforms other GD biomarkers for biochemical monitoring of patients receiving enzyme replacement therapy for all individuals. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Using Bayesian Belief Network (BBN) modelling for Rapid Source Term Prediction. RASTEP Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Knochenhauer, M.; Swaling, V.H.; Alfheim, P. [Scandpower AB, Sundbyberg (Sweden)

    2012-09-15

    The project is connected to the development of RASTEP, a computerized source term prediction tool aimed at providing a basis for improving off-site emergency management. RASTEP uses Bayesian belief networks (BBN) to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, timing, and pathway of released radio-nuclides). The output is a set of possible source terms with associated probabilities. In the NKS project, a number of complex issues associated with the integration of probabilistic and deterministic analyses are addressed. This includes issues related to the method for estimating source terms, signal validation, and sensitivity analysis. One major task within Phase 1 of the project addressed the problem of how to make the source term module flexible enough to give reliable and valid output throughout the accident scenario. Of the alternatives evaluated, it is recommended that RASTEP is connected to a fast running source term prediction code, e.g., MARS, with a possibility of updating source terms based on real-time observations. (Author)

  7. SITE project. Phase 1: Continuous data bit-error-rate testing

    Science.gov (United States)

    Fujikawa, Gene; Kerczewski, Robert J.

    1992-01-01

    The Systems Integration, Test, and Evaluation (SITE) Project at NASA LeRC encompasses a number of research and technology areas of satellite communications systems. Phase 1 of this project established a complete satellite link simulator system. The evaluation of proof-of-concept microwave devices, radiofrequency (RF) and bit-error-rate (BER) testing of hardware, testing of remote airlinks, and other tests were performed as part of this first testing phase. This final report covers the test results produced in phase 1 of the SITE Project. The data presented include 20-GHz high-power-amplifier testing, 30-GHz low-noise-receiver testing, amplitude equalization, transponder baseline testing, switch matrix tests, and continuous-wave and modulated interference tests. The report also presents the methods used to measure the RF and BER performance of the complete system. Correlations of the RF and BER data are summarized to note the effects of the RF responses on the BER.

  8. The effect of excipients on the stability and phase transition rate of xylazine hydrochloride and zopiclone.

    Science.gov (United States)

    Krūkle-Bērziņa, Kristīne; Actiņš, Andris

    2015-03-25

    The compatibility of thermodynamically unstable polymorph of two active pharmaceutical compounds (xylazine hydrochloride form X and zopiclone form C) with different excipients was investigated. The effects of the excipient and its amount in the sample on the thermal properties and possible chemical interactions were studied. The most commonly used excipients in the pharmaceutical industry - calcium carbonate, lactose hydrate, cellulose, magnesium stearate hydrate and calcium stearate hydrate were selected for this study. The dependence of the phase transition rate from an unstable to a more stable polymorph on the excipients and their amounts in the initial sample was analysed at 80°C, and the corresponding phase transition rate constants were calculated. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Crystallization history of lunar picritic basalt sample 12002 - Phase-equilibria and cooling-rate studies

    Science.gov (United States)

    Walker, D.; Kirkpatrick, R. J.; Longhi, J.; Hays, J. F.

    1976-01-01

    Experimental crystallization of a lunar picrite composition (sample 12002) at controlled linear cooling rates produces systematic changes in the temperature at which crystalline phases appear, in the texture, and in crystal morphology as a function of cooling rate. Phases crystallize in the order olivine, chromium spinel, pyroxene, plagioclase, and ilmenite during equilibrium crystallization, but ilmenite and plagioclase reverse their order of appearance and silica crystallizes in the groundmass during controlled cooling experiments. The partition of iron and magnesium between olivine and liquid is independent of cooling rate, temperature, and pressure. Comparison of the olivine nucleation densities in the lunar sample and in the experiments indicates that the sample began cooling at about 1 deg C/hr. Pyroxene size, chemistry, and growth instability spacings, as well as groundmass coarseness, all suggest that the cooling rate subsequently decreased by as much as a factor of 10 or more. The porphyritic texture of this sample, then, is produced at a decreasing, rather than a discontinuously increasing, cooling rate.

  10. Rapid wetland expansion during European settlement and its implication for marsh survival under modern sediment delivery rates

    Science.gov (United States)

    Kirwan, Matthew L.; Murray, A. Brad; Donnelly, Jeffrey P.; Corbett, D. Reide

    2011-01-01

    Fluctuations in sea-level rise rates are thought to dominate the formation and evolution of coastal wetlands. Here we demonstrate a contrasting scenario in which land-use-related changes in sediment delivery rates drive the formation of expansive marshland, and vegetation feedbacks maintain their morphology despite recent sediment supply reduction. Stratigraphic analysis and radiocarbon dating in the Plum Island Estuary (Massachusetts, United States) suggest that salt marshes expanded rapidly during the eighteenth and nineteenth centuries due to increased rates of sediment delivery following deforestation associated with European settlement. Numerical modeling coupled with the stratigraphic observations suggests that existing marshland could survive, but not form under the low suspended sediment concentrations observed in the estuary today. These results suggest that many of the expansive marshes that characterize the modern North American coast are metastable relicts of high nineteenth century sediment delivery rates, and that recent observations of degradation may represent a slow return to pre-settlement marsh extent. In contrast to ecosystem management practices in which restoring pre-anthropogenic conditions is seen as a way to increase ecosystem services, our results suggest that widespread efforts to restore valuable coastal wetlands actually prevent some systems from returning to a natural state.

  11. Rapid automated W-phase slip inversion for the Illapel great earthquake (2015, Mw = 8.3)

    Science.gov (United States)

    Benavente, Roberto; Cummins, Phil R.; Dettmer, Jan

    2016-03-01

    We perform rapid W-phase finite fault inversion for the 2015 Illapel great earthquake (Mw = 8.3). To evaluate the performance of the inversion in a near real time context, we divide seismic stations into four groups. The groups consider stations up to epicentral distances of 30°, 50°, 75°, and 90°, respectively. The results for the first group could have been available within 25 min after the origin time and the results for the last group within 1 h. The four results consistently show a peak slip of ˜10 m near the trench with trench perpendicular rake which is consistent with the tsunami genesis of the event. The slip location is similar to that in the preliminary U.S. Geological Survey solution. The inversion is automated and provides meaningful results within 25 min after the event. This makes the method particularly suited to emergency management and early warning at regional and teletsunami distances.

  12. Two-dimensional time-resolved x-ray diffraction study of dual phase rapid solidification in steels

    Science.gov (United States)

    Yonemura, Mitsuharu; Osuki, Takahiro; Terasaki, Hidenori; Komizo, Yuichi; Sato, Masugu; Toyokawa, Hidenori; Nozaki, Akiko

    2010-01-01

    The high intensity heat source used for fusion welding creates steep thermal gradients of 100 °C/s from 1800 °C. Further, the influence of preferred orientation is important for the observation of a directional solidification that follows the dendrite growth along the ⟨100⟩ direction toward the moving heat source. In the present study, we observed the rapid solidification of weld metal at a time resolution of 0.01-0.1 s by a two-dimensional time-resolved x-ray diffraction (2DTRXRD) system for real welding. The diffraction rings were dynamically observed by 2DTRXRD with synchrotron energy of 18 keV while the arc passes over the irradiation area of the x-rays. The arc power output was 10 V-150 A, and the scan speed of the arc was 1.0 mm/s. The temperature rise in instruments was suppressed by a water-cooled copper plate under the specimen. Further, the temperature distribution of the weld metal was measured by a thermocouple and correlated with the diffraction patterns. Consequently, solidification and solid phase transformation of low carbon steels and stainless steels were observed during rapid cooling by 2DTRXRD. In the low carbon steel, the microstructure is formed in a two step process, (i) formation of crystallites and (ii) increase of crystallinity. In stainless steel, the irregular interface layer of δ/γ in the quenched metal after solidification is expected to show the easy movement of dendrites at a lower temperature. In carbide precipitation stainless steel, it is easy for NbC to grow on δ phase with a little undercooling. Further, a mistlike pattern, which differs from the halo pattern, in the fusion zone gave some indication of the possibilities to observe the nucleation and the early solidification by 2DTRXRD.

  13. Rapid Development and Validation of Improved Reversed-Phase High-performance Liquid Chromatography Method for the Quantification of Mangiferin, a Polyphenol Xanthone Glycoside in Mangifera indica.

    Science.gov (United States)

    Naveen, P; Lingaraju, H B; Prasad, K Shyam

    2017-01-01

    Mangiferin, a polyphenolic xanthone glycoside from Mangifera indica, is used as traditional medicine for the treatment of numerous diseases. The present study was aimed to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC) method for the quantification of mangiferin from the bark extract of M. indica. RP-HPLC analysis was performed by isocratic elution with a low-pressure gradient using 0.1% formic acid: acetonitrile (87:13) as a mobile phase with a flow rate of 1.5 ml/min. The separation was done at 26°C using a Kinetex XB-C18 column as stationary phase and the detection wavelength at 256 nm. The proposed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification, and robustness by the International Conference on Harmonisation guidelines. In linearity, the excellent correlation coefficient more than 0.999 indicated good fitting of the curve and also good linearity. The intra- and inter-day precision showed indica. The present study was intended to develop and validate an RP-HPLC method for the quantification of mangiferin from the bark extract of M. indica. The developed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification and robustness by International Conference on Harmonization guidelines. This study proved that the developed assay by HPLC method is a simple, rapid and reliable for the quantification of the mangiferin from M. indica. Abbreviations Used:M. indica: Mangifera indica, RP-HPLC: Reversed-phase high-performance liquid chromatography, M/Z: Mass to charge ratio, ICH: International conference on harmonization, % RSD: Percentage of relative standard deviation, ppm: Parts per million, LOD: Limit of detection, LOQ: Limit of quantification.

  14. Rapid analysis of water- and fat-soluble vitamins by electrokinetic chromatography with polymeric micelle as pseudostationary phase.

    Science.gov (United States)

    Ni, Xinjiong; Xing, Xiaoping; Cao, Yuhua; Cao, Guangqun

    2014-11-28

    A novel polymeric micelle, formed by random copolymer poly (stearyl methacrylate-co-methacrylic acid) (P(SMA-co-MAA)) has been used as pseudostationary phase (PSP) in electrokinetic chromatography (EKC) for simultaneous and rapid determination of 11 kinds of water- and fat-soluble vitamins in this work. The running buffer consisting of 1% (w/v) P(SMA-co-MAA), 10% (v/v) 1-butanol, 20% (v/v) acetonitrile, and 30 mM Palitzsch buffer solution (pH 9.2) was applied to improve the selectivity and efficiency, as well as to shorten analysis time. 1-Butanol and acetonitrile as the organic solvent modifiers played the most important roles for rapid separation of these vitamins. The effects of organic solvents on microstructure of the polymeric micelle were investigated. The organic solvents swell the polymeric micelle by three folds, lower down the surface charge density and enhance the microenviromental polarity of the polymeric micelle. The 11 kinds of water- and fat-soluble vitamins could be baseline separated within 13 min. The method was applied to determine water- and fat-soluble vitamins in commercial vitamin sample; the recoveries were between 93% and 111% with the relative standard derivations (RSDs) less than 5%. The determination results matched the label claim. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Phase II stopping rules that employ response rates and early progression.

    Science.gov (United States)

    Goffin, John R; Tu, Dongsheng

    2008-08-01

    Phase II oncology trials traditionally have used response rate (RR) as the primary end point, but newer targeted agents require the consideration of alternative end points. High rates of early progressive disease (EPD) suggest inadequate drug activity and may be useful in the early stopping of trials. This study used a simulation to define a set of rules to assess a combined end point of RR and EPD. The simulation assumed a two-stage trial with a specified alpha error and power. It randomly generated the true response rate, r, of the agent under study and its true rate of early progressive disease, epd, for each run of the simulation. Two pairs of parameters were specified: (r(nul), epd(nul)) and (r(alt), epd(alt)). A drug was considered uninteresting for further development if r was less than or equal to r(nul) and epd was greater than or equal to epd(nul) (ie, the null hypothesis) and interesting for further development if r was greater than or equal to r(alt) or epd was less than or equal to epd(alt) (ie, the alternate hypotheses). Thresholds for the required number of patients with responses, n(r) and EPD, n(p), were generated for each set of parameters. Thresholds for n(r) and n(p) that satisfied the specified error rates were generated. There was at least an 89% likelihood that a study would be stopped at the first stage of accrual if r and epd were uninteresting. The simulation was able to establish stopping rules by combining the RR and the EPD that achieved the desired error rates. High rates of early stopping suggest that this design could shorten phase II trials of inactive agents.

  16. A High-Rate, Single-Crystal Model including Phase Transformations, Plastic Slip, and Twinning

    Energy Technology Data Exchange (ETDEWEB)

    Addessio, Francis L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bronkhorst, Curt Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bolme, Cynthia Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Explosive Science and Shock Physics Division; Brown, Donald William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Cerreta, Ellen Kathleen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lebensohn, Ricardo A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lookman, Turab [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Luscher, Darby Jon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Mayeur, Jason Rhea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Morrow, Benjamin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Rigg, Paulo A. [Washington State Univ., Pullman, WA (United States). Dept. of Physics. Inst. for Shock Physics

    2016-08-09

    An anisotropic, rate-­dependent, single-­crystal approach for modeling materials under the conditions of high strain rates and pressures is provided. The model includes the effects of large deformations, nonlinear elasticity, phase transformations, and plastic slip and twinning. It is envisioned that the model may be used to examine these coupled effects on the local deformation of materials that are subjected to ballistic impact or explosive loading. The model is formulated using a multiplicative decomposition of the deformation gradient. A plate impact experiment on a multi-­crystal sample of titanium was conducted. The particle velocities at the back surface of three crystal orientations relative to the direction of impact were measured. Molecular dynamics simulations were conducted to investigate the details of the high-­rate deformation and pursue issues related to the phase transformation for titanium. Simulations using the single crystal model were conducted and compared to the high-­rate experimental data for the impact loaded single crystals. The model was found to capture the features of the experiments.

  17. Recurrent selection with reduced herbicide rates results in the rapid evolution of herbicide resistance in Lolium rigidum.

    Science.gov (United States)

    Neve, Paul; Powles, Stephen

    2005-04-01

    There has been much debate regarding the potential for reduced rates of herbicide application to accelerate evolution of herbicide resistance. We report a series of experiments that demonstrate the potential for reduced rates of the acetyl-co enzyme A carboxylase (ACCase)-inhibiting herbicide diclofop-methyl to rapidly select for resistance in a susceptible biotype of Lolium rigidum. Thirty-six percent of individuals from the original VLR1 population survived application of 37.5 g diclofop-methyl ha(-1) (10% of the recommended field application rate). These individuals were grown to maturity and bulk-crossed to produce the VLR1 low dose-selected line VLR1 (0.1). Subsequent comparisons of the dose-response characteristics of the original and low dose-selected VLR1 lines demonstrated increased tolerance of diclofop-methyl in the selected line. Two further rounds of selection produced VLR1 lines that were resistant to field-applied rates of diclofop-methyl. The LD50 (diclofop-methyl dose required to cause 50% mortality) of the most resistant line was 56-fold greater than that of the original unselected VLR1 population, indicating very large increases in mean population survival after three cycles of selection. In vitro ACCase inhibition by diclofop acid confirmed that resistance was not due to an insensitive herbicide target-site. Cross-resistance studies showed increases in resistance to four herbicides: fluazifop-P-butyl, haloxyfop-R-methyl, clethodim and imazethapyr. The potential genetic basis of the observed response and implications of reduced herbicide application rates for management of herbicide resistance are discussed.

  18. Analysis of readmission rates to the intensive care unit after implementation of a rapid response team in a University Hospital.

    Science.gov (United States)

    Bergamasco E Paula, R; Tanita, M T; Festti, J; Queiroz Cardoso, L T; Carvalho Grion, C M

    2017-10-01

    To compare readmission rates to the intensive care unit (ICU) before and after the implementation of a rapid response team (RRT), and to identify risk factors for readmission. A quasi-experimental before-after study was carried out. A University Hospital. All patients discharged from the ICU from January to December 2008 (control group) and from January 2010 to December 2012 (intervention group). Implementation of an RRT. The data included demographic parameters, diagnoses upon admission, ICU readmission, APACHE II, SOFA, and TISS 28 scores, and routine daily assessment by an RRT of patients discharged from the ICU. During the study interval, 380 patients were analyzed in the period prior to the implementation of the RRT and 1361 after implementation. There was a tendency toward decreased readmission rates one year after RRT implementation. The APACHE II score and SOFA score at ICU discharge were independent factors associated to readmission, as well as clinical referral to the ICU. The RRT intervention resulted in a sustained decrease in readmission rates one year after implementation of this service. The use of a specialized team in health institutions can be recommended for ICU survivors. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  19. Rapid destruction of the rhodamine B using TiO2 photocatalyst in the liquid phase plasma.

    Science.gov (United States)

    Lee, Heon; Park, Sung Hoon; Park, Young-Kwon; Kim, Byung Hoon; Kim, Sun-Jae; Jung, Sang-Chul

    2013-09-16

    Rhodamine B (RhB) is widely used as a colorant in textiles and food stuffs, and is also a well-known water tracer fluorescent. It is harmful to human beings and animals, and causes irritation of the skin, eyes and respiratory tract. The carcinogenicity, reproductive and developmental toxicity, neurotoxicity and chronic toxicity toward humans and animals have been experimentally proven. RhB cannot be effectively removed by biological treatment due to the slow kinetics. Therefore, RhB is chosen as a model pollutant for liquid phase plasma (LPP) treatment in the present investigation. This paper presents experimental results for the bleaching of RhB from aqueous solutions in the presence of TiO2 photocatalyst with LPP system. Properties of generated plasma were investigated by optical emission spectroscopy methods. The results of electrical-discharge degradation of RhB showed that the decomposition rate increased with the applied voltage, pulse width, and frequency. The oxygen gas addition to reactant solution increases the degradation rate by active oxygen species. The RhB decomposition rate was shown to increase with the TiO2 particle dosage. This work presents the conclusions on the photocatalytic oxidation of RhB, as a function of plasma conditions, oxygen gas bubbling as well as TiO2 particle dosage. We knew that using the liquid phase plasma system with TiO2 photocatalyst at high speed we could remove the organic matter in the water.

  20. Drowning of a barrier coastline under rapid rates of relative sea-level rise during the 8.2 ka cooling event: Cause or coincidence?

    Science.gov (United States)

    Mellett, C.; Hodgson, D. M.; Lang, A.; Mauz, B.; Plater, A. J.

    2012-12-01

    Examples where barrier landforms and deposits are preserved offshore of a highstand shoreline are rare on contemporary continental shelves, and in the rock record. Therefore, understanding of the conditions required for preservation and the sedimentary processes-response to such factors is limited and heavily dependent on simulation models. Here, an integrated dataset of multibeam bathymetry and 2D seismic reflection profiles has uncovered an exceptionally well preserved drowned barrier complex at Hastings Bank, on the English Channel continental shelf, offshore of southeast England. Mapping of nine seismic stratigraphic units calibrated with lithological information from multiple vibrocores has enabled the interpretation of fluvial, shoreface, barrier, washover fan, back-barrier and tidal environments of deposition. Stratigraphic architecture is used as the basis for landscape evolution reconstructions that reveal phases of barrier progradation, degradation and retreat. Optical Stimulated Luminescence (OSL) dating of shoreface and beach deposits revealed ages in the range of 8.4 ± 0.2 ka and 7.8 ± 0.2 ka. These ages indicate the barrier developed under rapid rates of early Holocene sea-level rise and more specifically, correlate to the time period surrounding the 8.2 ka cooling event and associated sea-level 'jump'. To preserve a barrier beach including the barrier foreshore under such rapid rates of relative sea-level rise, sediment supply would have to be sufficient to keep pace to prevent the shoreline responding through continuous reworking, i.e. rollover. Further, the rate of transgression is conditioned by inherited topography with higher rates of retreat, and hence greater potential for drowning, expected across the shallowly dipping substrate. Using Hastings Bank as an example, it has also been demonstrated that the morphodynamic state of the barrier complex in terms of its ability to respond dynamically to relative sea-level rise, conditions its

  1. Gas hydrate formation rates from dissolved-phase methane in porous laboratory specimens

    Science.gov (United States)

    Waite, William F.; Spangenberg, E.K.

    2013-01-01

    Marine sands highly saturated with gas hydrates are potential energy resources, likely forming from methane dissolved in pore water. Laboratory fabrication of gas hydrate-bearing sands formed from dissolved-phase methane usually requires 1–2 months to attain the high hydrate saturations characteristic of naturally occurring energy resource targets. A series of gas hydrate formation tests, in which methane-supersaturated water circulates through 100, 240, and 200,000 cm3 vessels containing glass beads or unconsolidated sand, show that the rate-limiting step is dissolving gaseous-phase methane into the circulating water to form methane-supersaturated fluid. This implies that laboratory and natural hydrate formation rates are primarily limited by methane availability. Developing effective techniques for dissolving gaseous methane into water will increase formation rates above our observed (1 ± 0.5) × 10−7 mol of methane consumed for hydrate formation per minute per cubic centimeter of pore space, which corresponds to a hydrate saturation increase of 2 ± 1% per day, regardless of specimen size.

  2. Polypyrrole solid phase microextraction: A new approach to rapid sample preparation for the monitoring of antibiotic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Szultka, Malgorzata [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Kegler, Ricarda [Institute of Clinical Pharmacology, University of Rostock, Schillingallee 70, D-18057 Rostock (Germany); Fuchs, Patricia [Department of Anaesthesia and Intensive Care, University of Rostock, Schillingallee 35, D-18057 Rostock (Germany); Olszowy, Pawel [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Miekisch, Wolfram; Schubert, Jochen K. [Department of Anaesthesia and Intensive Care, University of Rostock, Schillingallee 35, D-18057 Rostock (Germany); Buszewski, Boguslaw [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Mundkowski, Ralf G., E-mail: ralf.mundkowski@med.uni-rostock.de [Institute of Clinical Pharmacology, University of Rostock, Schillingallee 70, D-18057 Rostock (Germany)

    2010-05-14

    Simple or even rapid bioanalytical methods are rare, since they generally involve complicated, time-consuming sample preparation from the biological matrices like LLE or SPE. SPME provides a promising approach to overcome these limitations. The full potential of this innovative technique for medical diagnostics, pharmacotherapy or biochemistry has not been tapped yet. In-house manufactured SPME probes with polypyrrole (PPy) coating were evaluated using three antibiotics of high clinical relevance - linezolid, daptomycin, and moxifloxacin - from PBS, plasma, and whole blood. The PPy coating was characterised by scanning electron microscopy. Influences of pH, inorganic salt, and blood anticoagulants were studied for optimum performance. Extraction yields were determined from stagnant media as well as re-circulating human blood using the heart-and-lung machine model system. The PPy-SPME fibres showed high extraction yields, particularly regarding linezolid. The reproducibility of the method was optimised to achieve RSDs of 9% or 17% and 7% for SPME from stagnant or re-circulating blood using fresh and re-used fibres, respectively. The PPy-SPME approach was demonstrated to meet the requirements of therapeutic monitoring of the drugs tested, even from re-circulating blood at physiological flow rates. SPME represents a rapid and simple dual-step procedure with potency to significantly reduce the effort and expenditure of complicated sample preparations in biomedical analysis.

  3. Gradual assembly of avian body plan culminated in rapid rates of evolution across the dinosaur-bird transition.

    Science.gov (United States)

    Brusatte, Stephen L; Lloyd, Graeme T; Wang, Steve C; Norell, Mark A

    2014-10-20

    The evolution of birds from theropod dinosaurs was one of the great evolutionary transitions in the history of life. The macroevolutionary tempo and mode of this transition is poorly studied, which is surprising because it may offer key insight into major questions in evolutionary biology, particularly whether the origins of evolutionary novelties or new ecological opportunities are associated with unusually elevated "bursts" of evolution. We present a comprehensive phylogeny placing birds within the context of theropod evolution and quantify rates of morphological evolution and changes in overall morphological disparity across the dinosaur-bird transition. Birds evolved significantly faster than other theropods, but they are indistinguishable from their closest relatives in morphospace. Our results demonstrate that the rise of birds was a complex process: birds are a continuum of millions of years of theropod evolution, and there was no great jump between nonbirds and birds in morphospace, but once the avian body plan was gradually assembled, birds experienced an early burst of rapid anatomical evolution. This suggests that high rates of morphological evolution after the development of a novel body plan may be a common feature of macroevolution, as first hypothesized by G.G. Simpson more than 60 years ago. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Evaluation of the use of conductimetry for the rapid and precise measurement of Salmonella spp. growth rates.

    Science.gov (United States)

    Sherry, A E; Patterson, M F; Kilpatrick, D; Madden, R H

    2006-10-01

    The growth rates of 14 Salmonella serovars in tryptone soy broth plus yeast extract (TSBYE) were estimated using conventional plating techniques and indirect conductimetry using a Don Whitley RABIT system. Both methods gave identical results for the maximum specific growth rate (mumax) P>0.05. However, using the conductimetric method, mumax for a single serovar was determined in less than 7 h, whereas the conventional method required an additional 24 h. In addition, the conductimetric method was considerably more precise, much less labour-intensive and required the use of considerably less consumables. Using conductimetry, a trained operator could accurately determine mumax for 24 serovars in 3 working days, but only one serovar using the conventional plate counting technique. Hence, the use of conductimetry can markedly increase the precision and accuracy of mumax determinations by allowing a very significant increase in the number of results obtained and in their precision. The data generated will allow the development of better mathematical growth models. The method can also be used to compare growth media and conditions and hence rapidly optimise detection protocols for this pathogen.

  5. Mutation Rates and Discriminating Power for 13 Rapidly-Mutating Y-STRs between Related and Unrelated Individuals.

    Directory of Open Access Journals (Sweden)

    Alessio Boattini

    Full Text Available Rapidly Mutating Y-STRs (RM Y-STRs were recently introduced in forensics in order to increase the differentiation of Y-chromosomal profiles even in case of close relatives. We estimate RM Y-STRs mutation rates and their power to discriminate between related individuals by using samples extracted from a wide set of paternal pedigrees and by comparing RM Y-STRs results with those obtained from the Y-filer set. In addition, we tested the ability of RM Y-STRs to discriminate between unrelated individuals carrying the same Y-filer haplotype, using the haplogroup R-M269 (reportedly characterised by a strong resemblance in Y-STR profiles as a case study. Our results, despite confirming the high mutability of RM Y-STRs, show significantly lower mutation rates than reference germline ones. Consequently, their power to discriminate between related individuals, despite being higher than the one of Y-filer, does not seem to improve significantly the performance of the latter. On the contrary, when considering R-M269 unrelated individuals, RM Y-STRs reveal significant discriminatory power and retain some phylogenetic signal, allowing the correct classification of individuals for some R-M269-derived sub-lineages. These results have important implications not only for forensics, but also for molecular anthropology, suggesting that RM Y-STRs are useful tools for exploring subtle genetic variability within Y-chromosomal haplogroups.

  6. Regulation of the Escherichia coli rmf gene encoding the ribosome modulation factor: growth phase- and growth rate-dependent control.

    OpenAIRE

    Yamagishi, M.; Matsushima, H; Wada, A.; Sakagami, M.; Fujita, N.; Ishihama, A

    1993-01-01

    Ribosome modulation factor (RMF) is a protein specifically associated with 100S ribosome dimers which start to accumulate in Escherichia coli cells upon growth transition from exponential to stationary phase. The structural gene, rmf, encoding the 55 amino acid residues RMF protein has been cloned from the 21.8 min region of the E. coli genome and sequenced. While rmf was silent in rapidly growing exponential phase cells, a high level of transcription took place concomitantly with the growth ...

  7. Performance of a Rapid and Simple HIV Testing Algorithm in a Multicenter Phase III Microbicide Clinical Trial▿

    Science.gov (United States)

    Crucitti, Tania; Taylor, Doug; Beelaert, Greet; Fransen, Katrien; Van Damme, Lut

    2011-01-01

    A multitest sequential algorithm based on rapid and simple (R/S) assays was applied for the diagnosis of HIV infection among participants in a phase 3 microbicide effectiveness trial. HIV testing was performed on finger-prick blood samples obtained from patients after their enrollment in the trial. The specimens were tested in a serial procedure using three different rapid tests (Determine HIV-1/2 [Abbott], SD Bioline HIV-1/2 3.0 [Standard Diagnostics], and Uni-Gold HIV [Trinity Biotech]). In the event of discordant results between the Determine HIV-1/2 and SD Bioline HIV-1/2 3.0 tests, the third assay (Uni-Gold HIV) determined the final outcome. When the final outcome was positive, a second specimen was collected and tested with the same algorithm, only if a positive result was obtained with this sample the participant was informed of her positive serostatus. A total of 5,734 postenrollment specimens obtained from 1,398 women were tested. Forty-six women tested positive according to the testing algorithm performed on the first collected specimen. Confirmatory testing results obtained at the ITM confirmed that 42 women were truly infected. Two of four initial false positives tested negative upon analysis of a second blood specimen. The other two tested false positive twice using specimens collected the same day. A high percentage of specimens reactive with the Determine HIV-1/2 assay was only observed at the study site in Kampala. This result did not appear to be associated with pregnancy or malaria infection. We conclude that HIV testing algorithms, including only R/S assays, are suitable for use in clinical trials, provided that adequate quality assurance procedures are in place. PMID:21752945

  8. Performance of a rapid and simple HIV testing algorithm in a multicenter phase III microbicide clinical trial.

    Science.gov (United States)

    Crucitti, Tania; Taylor, Doug; Beelaert, Greet; Fransen, Katrien; Van Damme, Lut

    2011-09-01

    A multitest sequential algorithm based on rapid and simple (R/S) assays was applied for the diagnosis of HIV infection among participants in a phase 3 microbicide effectiveness trial. HIV testing was performed on finger-prick blood samples obtained from patients after their enrollment in the trial. The specimens were tested in a serial procedure using three different rapid tests (Determine HIV-1/2 [Abbott], SD Bioline HIV-1/2 3.0 [Standard Diagnostics], and Uni-Gold HIV [Trinity Biotech]). In the event of discordant results between the Determine HIV-1/2 and SD Bioline HIV-1/2 3.0 tests, the third assay (Uni-Gold HIV) determined the final outcome. When the final outcome was positive, a second specimen was collected and tested with the same algorithm, only if a positive result was obtained with this sample the participant was informed of her positive serostatus. A total of 5,734 postenrollment specimens obtained from 1,398 women were tested. Forty-six women tested positive according to the testing algorithm performed on the first collected specimen. Confirmatory testing results obtained at the ITM confirmed that 42 women were truly infected. Two of four initial false positives tested negative upon analysis of a second blood specimen. The other two tested false positive twice using specimens collected the same day. A high percentage of specimens reactive with the Determine HIV-1/2 assay was only observed at the study site in Kampala. This result did not appear to be associated with pregnancy or malaria infection. We conclude that HIV testing algorithms, including only R/S assays, are suitable for use in clinical trials, provided that adequate quality assurance procedures are in place.

  9. A Rate-Theory–Phase-Field Model of Irradiation-Induced Recrystallization in UMo Nuclear Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Shenyang; Joshi, Vineet; Lavender, Curt A.

    2017-10-04

    Experiments showed that recrystallization dramatically speeds up the gas bubble swelling kinetics in metallic UMo fuels. In this work a recrystallization model is developed to study the effect of microstructures and radiation conditions on recrystallization kinetics. The model integrates the rate theory of intra-granular gas bubble and interstitial loop evolution and a phase field model of recrystallization zone evolution. A fast passage method is employed to describe one dimensional diffusion of interstitials which have diffusivity several order magnitude larger than that of the fission gas Xe. With the model, the effect of grain sizes on recrystallization kinetics is simulated.

  10. Development of a group contribution method to predict aqueous phase hydroxyl radical (HO*) reaction rate constants.

    Science.gov (United States)

    Minakata, Daisuke; Li, Ke; Westerhoff, Paul; Crittenden, John

    2009-08-15

    The hydroxyl radical (HO*) is a strong oxidant that reacts with electron-rich sites of organic compounds and initiates complex chain mechanisms. In order to help understand the reaction mechanisms, a rule-based model was previously developed to predict the reaction pathways. For a kinetic model, there is a need to develop a rate constant estimator that predicts the rate constants for a variety of organic compounds. In this study, a group contribution method (GCM) is developed to predict the aqueous phase HO* rate constants for the following reaction mechanisms: (1) H-atom abstraction, (2) HO* addition to alkenes, (3) HO* addition to aromatic compounds, and (4) HO* interaction with sulfur (S)-, nitrogen (N)-, or phosphorus (P)-atom-containing compounds. The GCM hypothesizes that an observed experimental rate constant for a given organic compound is the combined rate of all elementary reactions involving HO*, which can be estimated using the Arrhenius activation energy, E(a), and temperature. Each E(a) for those elementary reactions can be comprised of two parts: (1) a base part that includes a reactive bond in each reaction mechanism and (2) contributions from its neighboring functional groups. The GCM includes 66 group rate constants and 80 group contribution factors, which characterize each HO* reaction mechanism with steric effects of the chemical structure groups and impacts of the neighboring functional groups, respectively. Literature-reported experimental HO* rate constants for 310 and 124 compounds were used for calibration and prediction, respectively. The genetic algorithms were used to determine the group rate constants and group contribution factors. The group contribution factors for H-atom abstraction and HO* addition to the aromatic compounds were found to linearly correlate with the Taft constants, sigma*, and electrophilic substituent parameters, sigma+, respectively. The best calibrations for 83% (257 rate constants) and predictions for 62% (77

  11. Rapid needle-out patient-rollover approach after cone beam CT-guided lung biopsy: effect on pneumothorax rate in 1,191 consecutive patients

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Im [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Park, Chang Min; Goo, Jin Mo [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Lee, Sang Min [Seoul National University College of Medicine, Department of Radiology, Jongno-gu, Seoul (Korea, Republic of)

    2015-07-15

    To investigate the effect of rapid needle-out patient-rollover approach on the incidence of pneumothorax and drainage catheter placement due to pneumothorax in C-arm Cone-beam CT (CBCT)-guided percutaneous transthoracic needle biopsy (PTNB) of lung lesions. From May 2011 to December 2012, 1227 PTNBs were performed in 1191 patients with a 17-gauge coaxial needle. 617 biopsies were performed without (conventional-group) and 610 with rapid-rollover approach (rapid-rollover-group). Overall pneumothorax rates and incidences of pneumothorax requiring drainage catheter placement were compared between two groups. There were no significant differences in overall pneumothorax rates between conventional and rapid-rollover groups (19.8 % vs. 23.1 %, p = 0.164). However, pneumothorax rate requiring drainage catheter placement was significantly lower in rapid-rollover-group (1.6 %) than conventional-group (4.2 %) (p = 0.010). Multivariate analysis revealed male, age > 60, bulla crossed, fissure crossed, pleura to target distance > 1.3 cm, emphysema along needle tract, and pleural punctures ≥ 2 were significant risk factors of pneumothorax (p < 0.05). Regarding pneumothorax requiring drainage catheter placement, fissure crossed, bulla crossed, and emphysema along needle tract were significant risk factors (p < 0.05), whereas rapid-rollover approach was an independent protective factor (p = 0.002). The rapid needle-out patient-rollover approach significantly reduced the rate of pneumothorax requiring drainage catheter placement after CBCT-guided PTNB. (orig.)

  12. A rapid and validated HPLC method to quantify racecadotril metabolite, thiorphan, in human plasma using solid-phase extraction.

    Science.gov (United States)

    Xu, Fan; Yang, Lingli; Xu, Guili

    2008-01-01

    A HPLC method with UV detection was developed and validated for the determination of thiorphan in human plasma. Nevirapine was used as the internal standard. Separation was performed by a Waters sunfire C18 reversed-phase column maintained at 35 degrees C. The mobile phase was a mixture of 0.05 M phosphate buffer with the pH adjusted to 2.6 and acetonitrile (74:26, v/v) at a flow rate of 1.0 mL/min. The UV detector was set at 210 nm. An original pre-treatment of plasma samples was developed, based on solid-phase extraction (SPE) with solid-phase extraction cartridges (Oasis HLB 3 mL, 60 mg). The extraction recovery for plasma samples of thiorphan at 0.1, 0.4 and 2.0 microg/mL was 93.5%, 98.2% and 97.8%, respectively. The calibration curve was linear with the correlation coefficient (r) above 0.9998. Linearity was verified over the range of 0.05-4 microg/mL thiorphan in plasma. The limit of quantification (LOQ) is 0.05 microg/mL. The mean accuracy was 92.7-99.6%. The coefficient of variation (precision) in the within- and between-batch was 2.2-8.4% and 4.1-8.1%, respectively. This method is simple, economical and specific, and has been used successfully in a pharmacokinetic study of thiorphan.

  13. Seismicity and Deformation of Krafla Volcano, Iceland. Intervals of Low Seismicity Rate during Rapid Inflation Explained By the Kaiser Effect.

    Science.gov (United States)

    Heimisson, E. R.; Einarsson, P.; Sigmundsson, F.; Brandsdottir, B.

    2014-12-01

    The Krafla central volcano in NE-Iceland produced about 20 dike intrusions during a rifting episode 1975-1984. These intrusions were always preceded by inflation of the caldera. Once a dike started propagating rapid deflation was observed. The first deflation event began in December 1975 with a dike traveling laterally from the magma chamber. Leveling measurements revealed subsidence of 2 m close to the deflation center. In February 1976 a stage of inflation began and at the same time the seismicity rate in the caldera rose in good correlation with the inflation. A small intrusion started propagating in late September 1976 which was accompanied by maximum subsidence of about 14 cm. However in the next 3 inflation and deflation cycles the inflation periods were almost aseismic until the inflation level of previous cycle was exceeded. At that point a sharp increase in the caldera earthquake count was observed. This phenomenon was observed until late April 1977 when a fissure eruption occurred inside the caldera. By inverting leveling data from 87 stations for a Mogi source and regarding the volume change of the source as a measure of stress we suggest that this phenomenon can be explained by the Kaiser effect. The Kaiser effect is well known from rock mechanics where under cyclic loading and unloading rocks, and other materials, induce dramatic increase in acoustic emissions when the load exceeds that of previous cycles. Krafla demonstrated the same effect while the external stress field was not significantly changed during the aforementioned 3 inflation/deflation cycles. This condition was disturbed when eruption occurred inside the caldera. The state of stress in the vicinity of the magma chamber was changed and subsequent inflation periods were not accompanied by significant seismicity. These results indicate that the Kaiser effect is an important part of understanding the relationship between deformation and seismicity in active volcanoes. The importance of

  14. DNA microarray-based solid-phase RT-PCR for rapid detection and identification of influenza virus type A and subtypes H5 and H7

    DEFF Research Database (Denmark)

    Yi, Sun; Dhumpa, Raghuram; Bang, Dang Duong

    2011-01-01

    Endemic of avian influenza virus (AIV) in Asia and epizootics in some European regions have caused considerable public concern on a possible pandemic of AIV. A rapid method for virus detection and effective surveillance in wild avian, poultry production as well as in humans is required....... In this article, a DNA microarray-based solid-phase polymerase chain reaction (PCR) approach has been developed for rapid detection of influenza virus type A and for simultaneous identification of pathogenic virus subtypes H5 and H7. This solid-phase RT-PCR method combined reverse-transcription amplification...

  15. Rapid, low level determination of silver(I) in drinking water by colorimetric-solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Matteo P.; Porter, Marc D.; Fritz, James S

    2003-04-15

    A rapid, highly sensitive two-step procedure for the trace analysis of silver(I) is described. The method is based on: (1) the solid-phase extraction (SPE) of silver(I) from a water sample onto a disk impregnated with a silver-selective colorimetric reagent, and (2) the determination of the amount of complexed analyte extracted by the disk by diffuse reflectance spectroscopy (DRS). This method, called colorimetric-solid-phase extraction (C-SPE), was recently shown effective in determining low concentrations (0.1-5.0 mg/ml) of iodine and iodide in drinking water. This report extends C-SPE to the trace ({approx}4 {mu}g/l) level monitoring of silver(I) which is a biocide used on the International Space Station (ISS). The determination relies on the manually driven passage of a water sample through a polystyrene-divinylbenzene disk that has been impregnated with the colorimetric reagent 5-(p-dimethylaminobenzylidene) rhodanine (DMABR) and with an additive such as a semi-volatile alcohol (1,2-decanediol) or nonionic surfactant (Brij 30). The amount of concentrated silver(I) is then determined in a few seconds by using a hand-held diffuse reflectance spectrometer, with a total sample workup and readout time of {approx}60 s. Importantly, the additive induces the uptake of water by the disk, which creates a local environment conducive to silver(I) complexation at an extremely high concentration factor ({approx}800). There is no detectable reaction between silver(I) and impregnated DMABR in the absence of the additive. This strategy represents an intriguing new dimension for C-SPE in which additives, directly loaded in the disk material, provide a means to manipulate the reactivity of the impregnated reagent.

  16. Strain rate effects on the mechanical behavior of two Dual Phase steels in tension

    Science.gov (United States)

    Cadoni, E.; Singh, N. K.; Forni, D.; Singha, M. K.; Gupta, N. K.

    2016-05-01

    This paper presents an experimental investigation on the strain rate sensitivity of Dual Phase steel 1200 (DP1200) and Dual Phase steel 1400 (DP1400) under uni-axial tensile loads in the strain rate range from 0.001 s-1 to 600 s-1. These materials are advanced high strength steels (AHSS) having high strength, high capacity to dissipate crash energy and high formability. Flat sheet specimens of the materials having gauge length 10 mm, width 4 mm and thickness 2 mm (DP1200) and 1.25 mm (DP1400), are tested at room temperature (20∘C) on electromechanical universal testing machine to obtain their stress-strain relation under quasi-static condition (0.001 s-1), and on Hydro-Pneumatic machine and modified Hopkinson bar to study their mechanical behavior at medium (3 s-1, and 18 s-1) and high strain rates (200 s-1, 400 s-1, and 600 s-1) respectively. Tests under quasi-static condition are performed at high temperature (200∘C) also, and found that tensile flow stress is a increasing function of temperature. The stress-strain data has been analysed to determine the material parameters of the Cowper-Symonds and the Johnson-Cook models. A simple modification of the Johnson-Cook model has been proposed in order to obtain a better fit of tests at high temperatures. Finally, the fractographs of the broken specimens are taken by scanning electron microscope (SEM) to understand the fracture mechanism of these advanced high strength steels at different strain rates.

  17. Rapid ice unloading in the Fleming Glacier region, southern Antarctic Peninsula, and its effect on bedrock uplift rates

    Science.gov (United States)

    Zhao, Chen; King, Matt A.; Watson, Christopher S.; Barletta, Valentina R.; Bordoni, Andrea; Dell, Matthew; Whitehouse, Pippa L.

    2017-09-01

    Rapid regional warming in the Antarctic Peninsula has led to the significant retreat and eventual collapse of several major ice shelves since the 1970s, triggering the subsequent acceleration and thinning of their feeding glaciers. The Wordie Ice Shelf, lying off the west coast of the Antarctic Peninsula, has undergone long-term disintegration since the 1960s with a substantial calving event occurring around 1989, followed by continuous steady retreat and its almost-complete disappearance. The dynamic response of the upstream glaciers to the ice shelf collapse and the response of the solid Earth to the associated mass loss are not fully understood. To quantify the mass loss from the system, we generated a digital elevation model (DEM) using airborne vertical and oblique imagery from 1966 and compared it to a DEM derived from 2008 SPOT data. This analysis reveals lowering over that time of approximately 60 m at the front of Fleming Glacier. Using IceBridge and ICESat-2/GLAS data spanning 2002-2014, we show an increased rate of mean ice-surface lowering, with rates post-2008 more than twice those of 2002-2008. We use these load change data as a basis for the simulation of viscoelastic solid Earth deformation. We subtract modeled elastic deformation rates, and a suite of modeled viscous rates, from GPS-derived three-dimensional bedrock velocities at sites to the south of Fleming Glacier to infer properties of Earth rheology. Assuming the pre-breakup bedrock uplift was positive due to post-Last Glacial Maximum (LGM) ice retreat, our viscoelastic-corrected GPS uplift rates suggest upper mantle viscosities are > 2 ×1019 Pas and likely > 1 ×1020 Pas in this region, 1-2 orders of magnitude greater than previously found for the northern Antarctic Peninsula. Horizontal velocities at the GPS site nearest the Fleming Glacier, after the application of elastic and plate tectonic corrections, point away from Marguerite Bay rather than the present glacier front. This suggests

  18. Technique for the quantification of transient quadratic phase couplings between heart rate components.

    Science.gov (United States)

    Witte, H; Putsche, P; Eiselt, M; Arnold, M; Schmidt, K; Schack, B

    2001-03-01

    A technique for the time-variant analysis of quadratic phase coupling (QPC) in heart rate data is introduced and tested in 6 human neonates during quiet sleep. The set up of the approach is based up on the assumption that QPCs in the heart rate variability (HRV) are related to amplitude modulation effects. The application of the biamplitude deals with the detection of the coupling pattern and the bicoherence is used for the statistical quantification of coupling. By means of the results of bispectral analysis the time-variant processing has been adapted. The frequency-selective complex demodulation of the HRV leads to the envelope of the respiratory sinus arrhythmia (RSA), this has been used as one input for a time-variant coherence analysis. The other input is the low-pass filtered 10-second-rhythm of the HRV. A time-continuous quantification of the QPC, caused by amplitude modulation (10-second-rhythm modulates the RSA), is possible using this approach. According to our observed results in neonatal HRV both a phase co-ordination between the 10-second-rhythm and RSA as well as a non-linear coupling (amplitude modulation) between these HRV components can be seen.

  19. Microwave assisted extraction-solid phase extraction for high-efficient and rapid analysis of monosaccharides in plants.

    Science.gov (United States)

    Zhang, Ying; Li, Hai-Fang; Ma, Yuan; Jin, Yan; Kong, Guanghui; Lin, Jin-Ming

    2014-11-01

    Monosaccharides are the fundamental composition units of saccharides which are a common source of energy for metabolism. An effective and simple method consisting of microwave assisted extraction (MAE), solid phase extraction (SPE) and high performance liquid chromatography-refractive index detector (HPLC-RID) was developed for rapid detection of monosaccharides in plants. The MAE was applied to break down the structure of the plant cells and release the monosaccharides, while the SPE procedure was adopted to purify the extract before analysis. Finally, the HPLC-RID was employed to separate and analyze the monosaccharides with amino column. As a result, the extraction time was reduced to 17 min, which was nearly 85 times faster than soxhlet extraction. The recoveries of arabinose, xylose, fructose and glucose were 85.01%, 87.79%, 103.17%, and 101.24%, with excellent relative standard deviations (RSDs) of 1.94%, 1.13%, 0.60% and 1.67%, respectively. The proposed method was demonstrated to be efficient and time-saving, and had been applied to analyze monosaccharides in tobacco and tea successfully. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Pregnancy Rate Following Luteal Phase Support in Iranian Women with Polycystic Ovarian Syndrome

    Directory of Open Access Journals (Sweden)

    Fatemeh Foroozanfard

    2014-11-01

    Full Text Available Background: To assess the efficacy of luteal phase support (LPS using intravaginal progesterone (P on pregnancy rate in Iranian women with polycystic ovarian syndrome (PCOS who used a combination for ovulation induction consisting of letrozole or clomiphene citrate (CC and human menopausal gonadotropin (HMG. Materials and Methods:This was a randomized clinical trial undertaken in a fertility clinic in Kashan, Isfahan Province, Iran. A total of 198 patients completed treatment and follow up. Base on chosen ovulation induction programs, they were divided into two following group: i. CC group (n=98 used a combination consisting of CC (100 mg×5 day and HMG (150 IU×5 day and ii. letrozole group (n=100 used a combination consisting of letrozole (5 mg×5 day and HMG (150 IU×5 day. After human chorionic gonadotropin (hCG administration (5000 IU, the patients (n=122 who randomly received intravaginal P (Cyclogest, 400 mg daily were included in LPS group, while the rest (n=123 were included in non-P cycles group. The outcome was the comparison of chemical pregnancy rate between the groups. Results: Our findings showed that LPS was associated with a 10% higher pregnancy rate than in non-P cycles, although this difference did not reach statistical significant (p=0.08. LPS improved pregnancy rate in both CC (4% and letrozole (6% groups. In addition, patients who used letrozole for ovulation induction along with intravaginal P showed higher pregnancy rates than CC group. Conclusion: Administration of vaginal P for LPS may improve the pregnancy rate in women with PCOS using letrozole or CC in combination with HMG for ovulation induction (Registration Number: IRCT201206072967N4.

  1. Effects of Heating and Cooling Rates on Phase Transformations in 10 Wt Pct Ni Steel and Their Application to Gas Tungsten Arc Welding

    Science.gov (United States)

    Barrick, Erin J.; Jain, Divya; DuPont, John N.; Seidman, David N.

    2017-10-01

    10 wt pct Ni steel is a high-strength steel that possesses good ballistic resistance from the deformation induced transformation of austenite to martensite, known as the transformation-induced-plasticity effect. The effects of rapid heating and cooling rates associated with welding thermal cycles on the phase transformations and microstructures, specifically in the heat-affected zone, were determined using dilatometry, microhardness, and microstructural characterization. Heating rate experiments demonstrate that the Ac3 temperature is dependent on heating rate, varying from 1094 K (821 °C) at a heating rate of 1 °C/s to 1324 K (1051 °C) at a heating rate of 1830 °C/s. A continuous cooling transformation diagram produced for 10 wt pct Ni steel reveals that martensite will form over a wide range of cooling rates, which reflects a very high hardenability of this alloy. These results were applied to a single pass, autogenous, gas tungsten arc weld. The diffusion of nickel from regions of austenite to martensite during the welding thermal cycle manifests itself in a muddled, rod-like lath martensitic microstructure. The results of these studies show that the nickel enrichment of the austenite in 10 wt pct Ni steel plays a critical role in phase transformations during welding.

  2. Effects of Heating and Cooling Rates on Phase Transformations in 10 Wt Pct Ni Steel and Their Application to Gas Tungsten Arc Welding

    Science.gov (United States)

    Barrick, Erin J.; Jain, Divya; DuPont, John N.; Seidman, David N.

    2017-12-01

    10 wt pct Ni steel is a high-strength steel that possesses good ballistic resistance from the deformation induced transformation of austenite to martensite, known as the transformation-induced-plasticity effect. The effects of rapid heating and cooling rates associated with welding thermal cycles on the phase transformations and microstructures, specifically in the heat-affected zone, were determined using dilatometry, microhardness, and microstructural characterization. Heating rate experiments demonstrate that the Ac3 temperature is dependent on heating rate, varying from 1094 K (821 °C) at a heating rate of 1 °C/s to 1324 K (1051 °C) at a heating rate of 1830 °C/s. A continuous cooling transformation diagram produced for 10 wt pct Ni steel reveals that martensite will form over a wide range of cooling rates, which reflects a very high hardenability of this alloy. These results were applied to a single pass, autogenous, gas tungsten arc weld. The diffusion of nickel from regions of austenite to martensite during the welding thermal cycle manifests itself in a muddled, rod-like lath martensitic microstructure. The results of these studies show that the nickel enrichment of the austenite in 10 wt pct Ni steel plays a critical role in phase transformations during welding.

  3. PhoU Allows Rapid Adaptation to High Phosphate Concentrations by Modulating PstSCAB Transport Rate in Sinorhizobium meliloti.

    Science.gov (United States)

    diCenzo, George C; Sharthiya, Harsh; Nanda, Anish; Zamani, Maryam; Finan, Turlough M

    2017-09-15

    Maintenance of cellular phosphate homeostasis is essential for cellular life. The PhoU protein has emerged as a key regulator of this process in bacteria, and it is suggested to modulate phosphate import by PstSCAB and control activation of the phosphate limitation response by the PhoR-PhoB two-component system. However, a proper understanding of PhoU has remained elusive due to numerous complications of mutating phoU, including loss of viability and the genetic instability of the mutants. Here, we developed two sets of strains of Sinorhizobium meliloti that overcame these limitations and allowed a more detailed and comprehensive analysis of the biological and molecular activities of PhoU. The data showed that phoU cannot be deleted in the presence of phosphate unless PstSCAB is inactivated also. However, phoU deletions were readily recovered in phosphate-free media, and characterization of these mutants revealed that addition of phosphate to the environment resulted in toxic levels of PstSCAB-mediated phosphate accumulation. Phosphate uptake experiments indicated that PhoU significantly decreased the PstSCAB transport rate specifically in phosphate-replete cells but not in phosphate-starved cells and that PhoU could rapidly respond to elevated environmental phosphate concentrations and decrease the PstSCAB transport rate. Site-directed mutagenesis results suggested that the ability of PhoU to respond to phosphate levels was independent of the conformation of the PstSCAB transporter. Additionally, PhoU-PhoU and PhoU-PhoR interactions were detected using a bacterial two-hybrid screen. We propose that PhoU modulates PstSCAB and PhoR-PhoB in response to local, internal fluctuations in phosphate concentrations resulting from PstSCAB-mediated phosphate import.IMPORTANCE Correct maintenance of cellular phosphate homeostasis is critical in all kingdoms of life and in bacteria involves the PhoU protein. This work provides novel insights into the role of the Sinorhizobium

  4. Error rate of multi-level rapid prototyping trajectories for pedicle screw placement in lumbar and sacral spine

    Directory of Open Access Journals (Sweden)

    Merc Matjaz

    2014-10-01

    Full Text Available 【Abstract】Objective: Free-hand pedicle screw placement has a high incidence of pedicle perforation which can be reduced with fluoroscopy, navigation or an alternative rapid prototyping drill guide template. In our study the error rate of multi-level templates for pedicle screw placement in lumbar and sacral regions was evaluated. Methods: A case series study was performed on 11 patients. Seventy-two screws were implanted using multilevel drill guide templates manufactured with selective laser sintering. According to the optimal screw direction preoperatively defi ned, an analysis of screw misplacement was performed. Displacement, deviation and screw length difference were measured. The learning curve was also estimated. Results: Twelve screws (17% were placed more than 3.125 mm out of its optimal position in the centre of pedicle. The tip of the 16 screws (22% was misplaced more than 6.25 mm out of the predicted optimal position. According to our predefi ned goal, 19 screws (26% were implanted inaccurately. In 10 cases the screw length was selected incorrectly: 1 (1% screw was too long and 9 (13% were too short. No clinical signs of neurovascular lesion were observed. Learning curve was insignifi cantly noticeable (P=0.129. Conclusion: In our study, the procedure of manufacturing and applying multi-level drill guide templates has a 26% chance of screw misplacement. However, that rate does not coincide with pedicle perforation incidence and neurovascular injury. These facts along with a comparison to compatible studies make it possible to summarize that multi-level templates are satisfactorily accurate and allow precise screw placement with a clinically irrelevant mistake factor. Therefore templates could potentially represent a useful tool for routine pedicle screw placement. Key words: Drill guide; Template; Inaccuracy; Perforation; Radiation exposure

  5. Acidulants for japanese quails housed at high stocking rates at finishing phase

    Directory of Open Access Journals (Sweden)

    Ana Paula de Oliveira Saccomani

    2013-12-01

    the lowest intake at the stocking rate of 94.44 cm2. It follows that the stocking rate of 94.44 cm2/bird can be utilized without damages to the laying quails’ performance at finishing phase.

  6. An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes

    NARCIS (Netherlands)

    Zhang, Q.; van der Klift, E.J.C.; Janssen, H.-G.; van Beek, T.A.

    2009-01-01

    An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high

  7. Specific growth rate observer for the growing phase of a Polyhydroxybutyrate production process.

    Science.gov (United States)

    Jamilis, Martín; Garelli, Fabricio; Mozumder, Md Salatul Islam; Volcke, Eveline; De Battista, Hernán

    2015-03-01

    This paper focuses on the specific growth rate estimation problem in a Polyhydroxybutyrate bioplastic production process by industrial fermentation. The kinetics of the process are unknown and there are uncertainties in the model parameters and inputs. During the first hours of the growth phase of the process, biomass concentration can be measured online by an optical density sensor, but as cell density increases this method becomes ineffective and biomass measurement is lost. An asymptotic observer is developed to estimate the growth rate for the case without biomass measurement based on corrections made by a pH control loop. Furthermore, an exponential observer based on the biomass measurement is developed to estimate the growth rate during the first hours, which gives the initial condition to the asymptotic observer. Error bounds and robustness to uncertainties in the models and in the inputs are found. The estimation is independent of the kinetic models of the microorganism. The characteristic features of the observer are illustrated by numerical simulations and validated by experimental results.

  8. A Rate-Theory-Phase-Field Model of Irradiation-Induced Recrystallization in UMo Nuclear Fuels

    Science.gov (United States)

    Hu, Shenyang; Joshi, Vineet; Lavender, Curt A.

    2017-12-01

    In this work, we developed a recrystallization model to study the effect of microstructures and radiation conditions on recrystallization kinetics in UMo fuels. The model integrates the rate theory of intragranular gas bubble and interstitial loop evolutions and a phase-field model of recrystallization zone evolution. A first passage method is employed to describe one-dimensional diffusion of interstitials with a diffusivity value several orders of magnitude larger than that of fission gas xenons. With the model, the effect of grain sizes on recrystallization kinetics is simulated. The results show that (1) recrystallization in large grains starts earlier than that in small grains, (2) the recrystallization kinetics (recrystallization volume fraction) decrease as the grain size increases, (3) the predicted recrystallization kinetics are consistent with the experimental results, and (4) the recrystallization kinetics can be described by the modified Avrami equation, but the parameters of the Avrami equation strongly depend on the grain size.

  9. Rapid quantitation of fluoxetine and norfluoxetine in serum by micro-disc solid-phase extraction with high-performance liquid chromatography-ultraviolet absorbance detection.

    Science.gov (United States)

    Li, Kong M; Thompson, Murray R; McGregor, Iain S

    2004-05-25

    A rapid, robust and sensitive method for the extraction and quantitative analysis of serum fluoxetine (FLX) and norfluoxetine (N-FLX) using a solid-phase extraction (SPE) column and high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was developed and validated. The sample clean-up step was performed by simple micro-disc mixed-mode (non-polar and strong cation exchange (SCX)) SPE cartridges. Separation of analytes and internal standard (IS) clomipramine (CLO) from endogenous matrix interference was achieved using a Waters Symmetry C(8) (150 mm x 2.1 mm i.d., 5 microm) reversed-phase narrow bore column. The relative retention times were 8.5, 9.6 and 10.5 min for FLX, N-FLX and CLO, respectively with a low isocratic flow rate of 0.3 ml/min. Chromatographic run time was completed in 15 min and peak area ratios of analytes to IS were used for regression analysis of the calibration curve. The latter was linear from 10 to 4000 nmol/l using 0.5 ml sample volume of serum. The average recovery was 95.5% for FLX and 96.9% for N-FLX. The lowest limit of quantitation (LLOQ) for serum FLX and N-FLX was 10 nmol/l (on-column amount of 200 fmol). The method described was used to analyse serum samples obtained from rats given chronic FLX treatment and to examine the relationship between steady state serum drug concentrations and neurochemical changes in several brain regions.

  10. Influence of Cooling Rate on Phase Formationin Spray-Formed H13 Tool Steel

    Energy Technology Data Exchange (ETDEWEB)

    K. M. Mchugh; Y. Lin; Y. Zhou; E. J. Lavernia

    2006-04-01

    Spray forming is an effective way to process many tool steels into near-net-shape molds, dies and related tooling. The general approach involves depositing atomized droplets onto a refractory pattern in order to image the pattern’s features. The pattern is removed and the die is fitted into a standard holding fixture. This approach results in significant cost and lead-time savings compared to conventional machining, Spray-formed dies perform well in many industrial forming operations, oftentimes exhibiting extended die life over conventional dies. Care must be exercised when spray forming tool steel dies to minimize porosity and control the nature and distribution of phases and residual stresses. Selection of post-deposition heat treatment is important to tailor the die’s properties (hardness, strength, impact energy, etc.) for a particular application. This paper examines how the cooling rate and other processing parameters during spray processing and heat treatment of H13 tool steel influence phase formation. Results of case studies on spray-formed die performance in forging, extrusion and die casting, conducted by industry during production runs, will be described.

  11. Rapid determination of acetone in human blood by derivatization with pentafluorobenzyl hydroxylamine followed by headspace liquid-phase microextraction and gas chromatography/mass spectrometry.

    Science.gov (United States)

    Deng, Chunhui; Li, Ning; Wang, Xiaochuan; Zhang, Xiangmin; Zeng, Jia

    2005-01-01

    In the current work, a simple, rapid, accurate and inexpensive method was developed for the determination of acetone in human blood. The proposed method is based on derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA), followed by headspace liquid-phase microextraction (HS-LPME) and gas chromatography/mass spectrometry (GC/MS). In the present method, acetone in blood samples was derivatized with PFBHA and acetone oxime formed in several seconds. The formed oxime was enriched by HS-LPME using the organic solvent film (OSF) formed in a microsyringe barrel as extraction interface. Finally, the enriched oxime was analyzed by GC/MS in electron ionization (EI) mode. HS-LPME parameters including solvent, syringe plunger withdrawal rate, sampling volume, and extraction cycle were optimized and the method reproducibility, linearity, recovery and detection limit were studied. The proposed method was applied to determination of acetone in diabetes blood and normal blood. It has been shown that derivatization with HS-LPME and GC/MS is an alternative method for determination of the diabetes biomarker, acetone, in blood samples.

  12. Rectal temperature, distal sweat rate, and forearm blood flow following mild exercise at two phases of the circadian cycle.

    Science.gov (United States)

    Waterhouse, Jim; Aizawa, Seika; Nevill, Alan; Edwards, Benjamin; Weinert, Dietmar; Atkinson, Greg; Reilly, Thomas

    2007-01-01

    Changes in rectal temperature during mild exercise in the middle of the rising (11:00 h) and falling (23:00 h) phases of the circadian rhythm of resting core temperature have been compared. Seven healthy males were studied at rest, while exercising on a cycle ergometer (60 min at 80 W), and during the first 30 min of recovery. Rectal temperature, forearm blood flow, and forearm sweat rate were measured at 1 min intervals throughout. During exercise, there were significant time-of-day differences in the profiles of all three variables, and in the thresholds for increases in forearm blood flow and sweating. Forearm blood flow and sweat rate were recruited more rapidly and to a greater extent with evening exercise, and rectal temperature rose less. Analysis of covariance, with rectal temperature as the covariate, indicated the associations between it and forearm blood flow or sweating were significantly different (ptimes of day. There were also significant (ptime-of-day effects for forearm blood flow and sweating that were independent of rectal temperature. During recovery, rectal temperature fell more quickly in the late evening than late morning. Forearm blood flow and sweating also showed time-of-day differences, but these did not co-vary with rectal temperature. Control of rectal temperature during exercise and recovery appears to be more effective in the late evening than late morning, and differences in forearm blood flow and sweating, as well as factors independent of these two variables, contribute to this difference. The results support our "heat-gain/heat-loss modes" hypothesis.

  13. Using an aqueous two-phase polymer-salt system to rapidly concentrate viruses for improving the detection limit of the lateral-flow immunoassay.

    Science.gov (United States)

    Jue, Erik; Yamanishi, Cameron D; Chiu, Ricky Y T; Wu, Benjamin M; Kamei, Daniel T

    2014-12-01

    The development of point-of-need (PON) diagnostics for viruses has the potential to prevent pandemics and protects against biological warfare threats. Here we discuss the approach of using aqueous two-phase systems (ATPSs) to concentrate biomolecules prior to the lateral-flow immunoassay (LFA) for improved viral detection. In this paper, we developed a rapid PON detection assay as an extension to our previous proof-of-concept studies which used a micellar ATPS. We present our investigation of a more rapid polymer-salt ATPS that can drastically improve the assay time, and show that the phase containing the concentrated biomolecule can be extracted prior to macroscopic phase separation equilibrium without affecting the measured biomolecule concentration in that phase. We could therefore significantly decrease the time of the diagnostic assay with an early extraction time of just 30 min. Using this rapid ATPS, the model virus bacteriophage M13 was concentrated between approximately 2 and 10-fold by altering the volume ratio between the two phases. As the extracted virus-rich phase contained a high salt concentration which destabilized the colloidal gold indicator used in LFA, we decorated the gold nanoprobes with polyethylene glycol (PEG) to provide steric stabilization, and used these nanoprobes to demonstrate a 10-fold improvement in the LFA detection limit. Lastly, a MATLAB script was used to quantify the LFA results with and without the pre-concentration step. This approach of combining a rapid ATPS with LFA has great potential for PON applications, especially as greater concentration-fold improvements can be achieved by further varying the volume ratio. Biotechnol. Bioeng. 2014;111: 2499-2507. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  14. Effects of intermetallic phases on the electrochemical properties of rapidly-solidified Si-Cr alloys for rechargeable Li-ion batteries

    Science.gov (United States)

    Ha, Jeong Ae; Jo, In Joo; Park, Won-Wook; Sohn, Keun Yong

    2016-09-01

    The microstructures and the electrochemical properties of rapidly-solidified Si-Cr alloys of various compositions were investigated in order to elucidate the effects of intermetallic phases on the cyclic energy capacity of the materials. Rapidly-solidified ribbons of the alloys were prepared by using a melt-spinning process, which is one of the most efficient rapid-solidification processes. The ribbons were fragmented by using a ball-milling process to produce powders of the alloys. To examine the electrochemical characteristics of the alloys, we mixed each of the alloy powders with Ketjenblack®, a conductive material, and a binder dissolved in deionized water and used it to form electrodes. The electrolyte used was 1.5-M LiPF6 dissolved in ethyl carbonate/dimethyl carbonate/fluoroethylene carbonate. The microstructures and the phases of the alloys were analyzed by using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analyses. The obtained results showed that the microstructures of the rapidly-solidified Si-Cr alloys were composed of Si and CrSi2 phases. Fine Si particles with diameters of 50 - 100 nm were observed in an eutectic constituent while the sizes of the primary Si and CrSi2 phases were relatively larger at 500 - 900 nm. The specific energy capacities ( C) of the Si-Cr alloys decreased linearly with increasing volume fraction ( f) of the CrSi2 phase as follows: C = -1,667 f + 1,978 after the 50th cycle. The Columbic efficiency after the 3rd cycle increased slightly with increasing volume fraction of the CrSi2 phase; this was effective in improving the cycling capacity of the Si particles.

  15. Quantitative assessment of effects of phase aberration and noise on high-frame-rate imaging.

    Science.gov (United States)

    Chen, Hong; Lu, Jian-yu

    2013-01-01

    The goal of this paper is to quantitatively study effects of phase aberration and noise on high-frame-rate (HFR) imaging using a set of traditional and new parameters. These parameters include the traditional -6-dB lateral resolution, and new parameters called the energy ratio (ER) and the sidelobe ratio (SR). ER is the ratio between the total energy of sidelobe and the total energy of mainlobe of a point spread function (PSF) of an imaging system. SR is the ratio between the peak value of the sidelobe and the peak value of the mainlobe of the PSF. In the paper, both simulation and experiment are conducted for a quantitative assessment and comparison of the effects of phase aberration and noise on the HFR and the conventional delay-and-sum (D&S) imaging methods with the set of parameters. In the HFR imaging method, steered plane waves (SPWs) and limited-diffraction beams (LDBs) are used in transmission, and received signals are processed with the Fast Fourier Transform to reconstruct images. In the D&S imaging method, beams focused at a fixed depth are used in transmission and dynamically focused beams are used in reception for image reconstruction. The simulation results show that the average differences between the -6-dB lateral beam widths of the HFR imaging and the D&S imaging methods are -0.1337mm for SPW and -0.1481mm for LDB, which means that the HFR imaging method has a higher lateral image resolution than the D&S imaging method since the values are negative. In experiments, the average differences are also negative, i.e., -0.2804mm for SPW and -0.3365mm for LDB. The results for the changes of ER and SR between the HFR and the D&S imaging methods have negative values, too. After introducing phase aberration and noise, both simulations and experiments show that the HFR imaging method has also less change in the -6-dB lateral resolution, ER, and SR as compared to the conventional D&S imaging method. This means that the HFR imaging method is less sensitive to

  16. Mechanical and Microstructural Investigation of Dual Phase Stainless Steel (LDX2101) under a wide range of strain rates

    Science.gov (United States)

    Ameri, Ali; Escobedo-Diaz, Juan; Ashraf, Mahmud; Brown, Andrew; Hazell, Paul; Hutchison, Wayne; Quadir, Zakaria

    2017-06-01

    The mechanical response and the microstructural evolution of lean duplex stainless steel 2101 (LDSS 2101) under a wide range of strain rates has been investigated. Experimental testing spanned from quasistatic, high strain-rate (Split Hopkinson Pressure Bar) and shock loading. The microstructural changes, e.g. phase transformation and grain rotation, texture and substructure evolution, were investigated by optical microscopy, X-ray diffraction (XRD) and electron-backscattered diffraction (EBSD). A significant increase in the yield stress with increasing strain rate was observed. The plastic deformation, e.g. work hardening rate, was also depended on the strain-rate. The threshold stress for the iron-epsilon phase transformation was obtained from free surface velocity measurements and the retained high pressure phase was assessed by XRD measurements.

  17. A Novel Encoded Excitation Scheme in a Phased Array for The Improving Data Acquisition Rate

    Directory of Open Access Journals (Sweden)

    César Gutiérrez-Fernández

    2013-12-01

    Full Text Available One of the challenges of phased array (PA ultrasonic imaging systems is their limited capability to deal with real-time applications, such as echocardiography and obstetrics. In its most basic outline, these systems require emitting and receiving with the entire array for each image line to be acquired; therefore, with many image lines, a higher acquisition time and a lower frame rate. This constraint requires one to find alternatives to reduce the total number of emissions needed to obtain the whole image. In this work, we propose a new PA scheme based on the Code Division Multiple Access (CDMA technique, where a different code is assigned to each steering direction, allowing the array to emit in several directions simultaneously. However, the use of encoding techniques produces a reduction of the image contrast because of the interferences between codes. To solve this, a new scheme based on merging several images is proposed, allowing the system to get close to the theoretical maximum frame rate, as well as to limit the loss of contrast, intrinsic to the technique.

  18. Nonlinear detection for a high rate extended binary phase shift keying system.

    Science.gov (United States)

    Chen, Xian-Qing; Wu, Le-Nan

    2013-03-28

    The algorithm and the results of a nonlinear detector using a machine learning technique called support vector machine (SVM) on an efficient modulation system with high data rate and low energy consumption is presented in this paper. Simulation results showed that the performance achieved by the SVM detector is comparable to that of a conventional threshold decision (TD) detector. The two detectors detect the received signals together with the special impacting filter (SIF) that can improve the energy utilization efficiency. However, unlike the TD detector, the SVM detector concentrates not only on reducing the BER of the detector, but also on providing accurate posterior probability estimates (PPEs), which can be used as soft-inputs of the LDPC decoder. The complexity of this detector is considered in this paper by using four features and simplifying the decision function. In addition, a bandwidth efficient transmission is analyzed with both SVM and TD detector. The SVM detector is more robust to sampling rate than TD detector. We find that the SVM is suitable for extended binary phase shift keying (EBPSK) signal detection and can provide accurate posterior probability for LDPC decoding.

  19. Nonlinear Detection for a High Rate Extended Binary Phase Shift Keying System

    Directory of Open Access Journals (Sweden)

    Le-Nan Wu

    2013-03-01

    Full Text Available The algorithm and the results of a nonlinear detector using a machine learning technique called support vector machine (SVM on an efficient modulation system with high data rate and low energy consumption is presented in this paper. Simulation results showed that the performance achieved by the SVM detector is comparable to that of a conventional threshold decision (TD detector. The two detectors detect the received signals together with the special impacting filter (SIF that can improve the energy utilization efficiency. However, unlike the TD detector, the SVM detector concentrates not only on reducing the BER of the detector, but also on providing accurate posterior probability estimates (PPEs, which can be used as soft-inputs of the LDPC decoder. The complexity of this detector is considered in this paper by using four features and simplifying the decision function. In addition, a bandwidth efficient transmission is analyzed with both SVM and TD detector. The SVM detector is more robust to sampling rate than TD detector. We find that the SVM is suitable for extended binary phase shift keying (EBPSK signal detection and can provide accurate posterior probability for LDPC decoding.

  20. Weakly doped InP layers prepared by liquid phase epitaxy using a modulated cooling rate

    Science.gov (United States)

    Krukovskyi, R.; Mykhashchuk, Y.; Kost, Y.; Krukovskyi, S.; Saldan, I.

    2017-04-01

    Epitaxial structures based on InP are widely used to manufacture a number of devices such as microwave transistors, light-emitting diodes, lasers and Gunn diodes. However, their temporary instability caused by heterogeneity of resistivity along the layer thickness and the influence of various external or internal factors prompts the need for the development of a new reliable technology for their preparation. Weak doping by Yb, Al and Sn together with modulation of the cooling rate applied to prepare InP epitaxial layers is suggested to be adopted within the liquid phase epitaxy (LPE) method. The experimental results confirm the optimized conditions created to get a uniform electron concentration in the active n-InP layer. A sharp profile of electron concentration in the n+-InP(substrate)/n-InP/n+-InP epitaxial structure was observed experimentally at the proposed modulated cooling rate of 0.3 °С-1.5 °С min-1. The proposed technological method can be used to control the electrical and physical properties of InP epitaxial layers to be used in Gunn diodes.

  1. Rapid healing of cutaneous leishmaniasis by high-frequency electrocauterization and hydrogel wound care with or without DAC N-055: a randomized controlled phase IIa trial in Kabul.

    Directory of Open Access Journals (Sweden)

    Ahmad Fawad Jebran

    2014-02-01

    Full Text Available Anthroponotic cutaneous leishmaniasis (CL due to Leishmania (L. tropica infection is a chronic, frequently disfiguring skin disease with limited therapeutic options. In endemic countries healing of ulcerative lesions is often delayed by bacterial and/or fungal infections. Here, we studied a novel therapeutic concept to prevent superinfections, accelerate wound closure, and improve the cosmetic outcome of ACL.From 2004 to 2008 we performed a two-armed, randomized, double-blinded, phase IIa trial in Kabul, Afghanistan, with patients suffering from L. tropica CL. The skin lesions were treated with bipolar high-frequency electrocauterization (EC followed by daily moist-wound-treatment (MWT with polyacrylate hydrogel with (group I or without (group II pharmaceutical sodium chlorite (DAC N-055. Patients below age 5, with facial lesions, pregnancy, or serious comorbidities were excluded. The primary, photodocumented outcome was the time needed for complete lesion epithelialization. Biopsies for parasitological and (immunohistopathological analyses were taken prior to EC (1(st, after wound closure (2(nd and after 6 months (3(rd. The mean duration for complete wound closure was short and indifferent in group I (59 patients, 43.1 d and II (54 patients, 42 d; p = 0.83. In patients with Leishmania-positive 2(nd biopsies DAC N-055 caused a more rapid wound epithelialization (37.2 d vs. 58.3 d; p = 0.08. Superinfections occurred in both groups at the same rate (8.8%. Except for one patient, reulcerations (10.2% in group I, 18.5% in group II; p = 0.158 were confined to cases with persistent high parasite loads after healing. In vitro, DAC N-055 showed a leishmanicidal effect on pro- and amastigotes.Compared to previous results with intralesional antimony injections, the EC plus MWT protocol led to more rapid wound closure. The tentatively lower rate of relapses and the acceleration of wound closure in a subgroup of patients with parasite persistence warrant

  2. Rapid Healing of Cutaneous Leishmaniasis by High-Frequency Electrocauterization and Hydrogel Wound Care with or without DAC N-055: A Randomized Controlled Phase IIa Trial in Kabul

    Science.gov (United States)

    Steiner, Reto; Wentker, Pia; Mahfuz, Farouq; Stahl, Hans-Christian; Amin, Faquir Mohammad; Bogdan, Christian; Stahl, Kurt-Wilhelm

    2014-01-01

    Background Anthroponotic cutaneous leishmaniasis (CL) due to Leishmania (L.) tropica infection is a chronic, frequently disfiguring skin disease with limited therapeutic options. In endemic countries healing of ulcerative lesions is often delayed by bacterial and/or fungal infections. Here, we studied a novel therapeutic concept to prevent superinfections, accelerate wound closure, and improve the cosmetic outcome of ACL. Methodology/Principal Findings From 2004 to 2008 we performed a two-armed, randomized, double-blinded, phase IIa trial in Kabul, Afghanistan, with patients suffering from L. tropica CL. The skin lesions were treated with bipolar high-frequency electrocauterization (EC) followed by daily moist-wound-treatment (MWT) with polyacrylate hydrogel with (group I) or without (group II) pharmaceutical sodium chlorite (DAC N-055). Patients below age 5, with facial lesions, pregnancy, or serious comorbidities were excluded. The primary, photodocumented outcome was the time needed for complete lesion epithelialization. Biopsies for parasitological and (immuno)histopathological analyses were taken prior to EC (1st), after wound closure (2nd) and after 6 months (3rd). The mean duration for complete wound closure was short and indifferent in group I (59 patients, 43.1 d) and II (54 patients, 42 d; p = 0.83). In patients with Leishmania-positive 2nd biopsies DAC N-055 caused a more rapid wound epithelialization (37.2 d vs. 58.3 d; p = 0.08). Superinfections occurred in both groups at the same rate (8.8%). Except for one patient, reulcerations (10.2% in group I, 18.5% in group II; p = 0.158) were confined to cases with persistent high parasite loads after healing. In vitro, DAC N-055 showed a leishmanicidal effect on pro- and amastigotes. Conclusions/Significance Compared to previous results with intralesional antimony injections, the EC plus MWT protocol led to more rapid wound closure. The tentatively lower rate of relapses and the acceleration of

  3. Rapid healing of cutaneous leishmaniasis by high-frequency electrocauterization and hydrogel wound care with or without DAC N-055: a randomized controlled phase IIa trial in Kabul.

    Science.gov (United States)

    Jebran, Ahmad Fawad; Schleicher, Ulrike; Steiner, Reto; Wentker, Pia; Mahfuz, Farouq; Stahl, Hans-Christian; Amin, Faquir Mohammad; Bogdan, Christian; Stahl, Kurt-Wilhelm

    2014-02-01

    Anthroponotic cutaneous leishmaniasis (CL) due to Leishmania (L.) tropica infection is a chronic, frequently disfiguring skin disease with limited therapeutic options. In endemic countries healing of ulcerative lesions is often delayed by bacterial and/or fungal infections. Here, we studied a novel therapeutic concept to prevent superinfections, accelerate wound closure, and improve the cosmetic outcome of ACL. From 2004 to 2008 we performed a two-armed, randomized, double-blinded, phase IIa trial in Kabul, Afghanistan, with patients suffering from L. tropica CL. The skin lesions were treated with bipolar high-frequency electrocauterization (EC) followed by daily moist-wound-treatment (MWT) with polyacrylate hydrogel with (group I) or without (group II) pharmaceutical sodium chlorite (DAC N-055). Patients below age 5, with facial lesions, pregnancy, or serious comorbidities were excluded. The primary, photodocumented outcome was the time needed for complete lesion epithelialization. Biopsies for parasitological and (immuno)histopathological analyses were taken prior to EC (1(st)), after wound closure (2(nd)) and after 6 months (3(rd)). The mean duration for complete wound closure was short and indifferent in group I (59 patients, 43.1 d) and II (54 patients, 42 d; p = 0.83). In patients with Leishmania-positive 2(nd) biopsies DAC N-055 caused a more rapid wound epithelialization (37.2 d vs. 58.3 d; p = 0.08). Superinfections occurred in both groups at the same rate (8.8%). Except for one patient, reulcerations (10.2% in group I, 18.5% in group II; p = 0.158) were confined to cases with persistent high parasite loads after healing. In vitro, DAC N-055 showed a leishmanicidal effect on pro- and amastigotes. Compared to previous results with intralesional antimony injections, the EC plus MWT protocol led to more rapid wound closure. The tentatively lower rate of relapses and the acceleration of wound closure in a subgroup of patients with parasite persistence warrant

  4. 100 kV/2A three-phase constant-current repetitive-rate charging equipment

    CERN Document Server

    Tan Yu Gang; Chen Li Dong; Guo Zhi Gang; Zou Xiao Bing; Luo Min; Cao Shao Yun; Chang An Bi

    2002-01-01

    A 100 kV/2A three-phase constant-current repetitive-rate charging equipment was designed and constructed. A three-phase L-C converter is adopted as constant-current power source. Six Insulated Gate Bipolar Transistors (IGBTs) are connected in parallel to control the stop of charge. A Programmable Logical Controller (PLC) is the central element of the control unit. The equipment is used in the repetitive-rate discharge features test of the switch. It works stably under the conditions of 2A charging current, 10 Hz operating voltage, 100 kV repetitive rate and 1 mu F capacitor

  5. Diet density in rearing and reproductive phases influences carcass composition, pregnancy rate and litter performance of primiparous rabbit does

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio dos Santos Teixeira

    2017-06-01

    Full Text Available The objective was to evaluate the effect of the interaction of diet density in the rearing phase×diet density in the reproductive phase on carcass composition, pregnancy rate, and litter performance of primiparous rabbit does. The experiment followed a 2×2×2 factorial (2 seasons, 2 diet densities in the rearing phase and 2 diet densities in reproductive phase, that is, from mating to weaning of the first litter. The reference diet (RD contained 184 g/kg of crude protein (CP, 165 g/kg of acid detergent fibre (ADF and 10.5 MJ/kg of digestible energy (DE. The low-density diet (LD had 147 g/kg of CP, 24 g/kg of ADF and 8.4 MJ/kg of DE. The treatments were applied from 70 d of age until weaning of the first litter at 35 d of age. Ninety-six females from the Botucatu Genetic Group (24 females/experimental group were mated at 142 d of age. On day 12 of gestation, 23 does were slaughtered to evaluate weights of carcass, organs and dissectible fat, and embryo implantation rate. No effects of diet density in the rearing or in the reproductive phases were detected on feed intake of does during the reproductive phase. Does fed LD during the rearing phase showed lower body weight at mating (3574±47 vs. 3866±43 g, P=0.0001 and during most of the reproductive phase, but they lost less weight in the peripartum. Perirenal fat was lighter in these does (72.8±10.0 vs. 102.1±9.6 g, P=0.048 and they showed a lower pregnancy rate (76.1 vs. 91.7%, P=0.045. The does fed RD in the reproductive phase were heavier during this phase (4055±40 g vs. 3887±41 g, P=0.0044. The does fed LD in rearing phase and RD in the reproductive phase showed larger litters at weaning, due to decreased kit mortality, than those fed RD in both phases (6.16±0.47 vs. 3.93±0.71, P=0.0361. Litters were lighter at weaning when LD was fed in the reproductive phase (3582±201 vs. 4733±187, P<0.0001. Feeding a low-density diet during the rearing phase and a reference diet during the

  6. Selective aluminum dissolution as a means to observe the microstructure of nanocrystalline intermetallic phases from Al-Fe-Cr-Ti-Ce rapidly solidified alloy.

    Science.gov (United States)

    Michalcová, Alena; Vojtěch, Dalibor; Novák, Pavel

    2013-02-01

    Rapidly solidified aluminum alloys are promising materials with very fine microstructure. The microscopy observation of these materials is complicated due to overlay of fcc-Al matrix and different intermetallic phases. A possible way to solve this problem is to dissolve the Al matrix. By this process powder formed by single intermetallic phase particles is obtained. In this paper a new aqueous based dissolving agent for Al-based alloy is presented. The influence of oxidation agent (FeCl(3)) concentration on quality of extraction process was studied. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. High Growth Rate Hydride Vapor Phase Epitaxy at Low Temperature through Use of Uncracked Hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Kevin L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Simon, John D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ptak, Aaron J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Braun, Anna [Rose-Hulman Institute of Technology

    2018-01-22

    We demonstrate hydride vapor phase epitaxy (HVPE) of GaAs with unusually high growth rates (RG) at low temperature and atmospheric pressure by employing a hydride-enhanced growth mechanism. Under traditional HVPE growth conditions that involve growth from Asx species, RG exhibits a strong temperature dependence due to slow kinetics at the surface, and growth temperatures >750 degrees C are required to obtain RG > 60 um/h. We demonstrate that when the group V element reaches the surface in a hydride, the kinetic barrier is dramatically reduced and surface kinetics no longer limit RG. In this regime, RG is dependent on mass transport of uncracked AsH3 to the surface. By controlling the AsH3 velocity and temperature profile of the reactor, which both affect the degree of AsH3 decomposition, we demonstrate tuning of RG. We achieve RG above 60 um/h at temperatures as low as 560 degrees C and up to 110 um/h at 650 degrees C. We incorporate high-RG GaAs into solar cell devices to verify that the electronic quality does not deteriorate as RG is increased. The open circuit voltage (VOC), which is a strong function of non-radiative recombination in the bulk material, exhibits negligible variance in a series of devices grown at 650 degrees C with RG = 55-110 um/h. The implications of low temperature growth for the formation of complex heterostructure devices by HVPE are discussed.

  8. High basal melt rates observed on Store Glacier, West Greenland, using phase-sensitive FMCW radar

    Science.gov (United States)

    Young, T. J.; Christoffersen, P.; Nicholls, K. W.; Lok, L. B.; Doyle, S. H.; Hubbard, B. P.; Stewart, C.; Hofstede, C. M.; Bougamont, M. H.; Todd, J.; Brennan, P. V.; Hubbard, A.

    2016-12-01

    The Greenland ice sheet is losing mass, and is currently contributing 1 mm/year to global sea level rise. The large majority of these changes can be attributed to the recent acceleration in flow of marine-terminating outlet glaciers within the last several decades. Such fast ice flow is characterised by ice deformation, as well as basal motion. However, there are few direct observations of either of these contributing mechanisms due to the difficulty of accessing the subglacial environment. In particular, although basal melt rates have been measured on ice shelves for decades, there exist almost no equivalent observations for grounded ice sheets. We present the first time series of directly-measured rates of basal melting at the bed of Store Glacier, a major outlet glacier flowing into Uummannaq Fjord in West Greenland. The measurements were obtained using a phase-sensitive, frequency modulated continuous wave (FMCW) radar system installed 30 km upflow of the calving terminus at a location where the surface velocity of the glacier is 700 m/year. Radar data were recorded every 4 hours from 26 July to 11 December 2014. The same site was used to instrument 610-m-deep boreholes drilled to the bed as part of the Subglacial Access and Fast Ice research Experiment (SAFIRE). With internal and basal reflector ranges captured at high spatial (millimetre) and temporal (hourly) resolutions, we obtained a unique, 6-month-long time series of ice deformation and basal melting coincident with englacial and subglacial borehole measurements. Here, we report sustained basal melting of 3 m/year during winter, and maxima of 20 m/year during summer when basal motion is enhanced by surface water delivered to the bed. The lower, but more constant rate of winter basal melting is likely to be driven by frictional heat generated from basal sliding. These discoveries indicate that basal melting beneath Greenland's fast flowing outlet glaciers is considerably higher than basal melting reported

  9. Rapid Quantification of the Toxic Alga Prymnesium parvum in Natural Samples by Use of a Specific Monoclonal Antibody and Solid-Phase Cytometry

    DEFF Research Database (Denmark)

    West, N. J.; Bacchieri, R.; Hansen, Gert

    2006-01-01

    The increasing incidence of harmful algal blooms around the world and their associated health and economic effects require the development of methods to rapidly and accurately detect and enumerate the target species. Here we describe use of a solid-phase cytometer to detect and enumerate the toxi......-phase cytometer can be used to rapidly enumerate natural P. parvum cells and that it could be used to detect other toxic algae, with an appropriate antibody or DNA probe.......The increasing incidence of harmful algal blooms around the world and their associated health and economic effects require the development of methods to rapidly and accurately detect and enumerate the target species. Here we describe use of a solid-phase cytometer to detect and enumerate the toxic...... alga Prymnesium parvum in natural samples, using a specific monoclonal antibody and indirect immunofluorescence. The immunoglobulin G antibody 16E4 exhibited narrow specificity in that it recognized several P. parvum strains and a Prymnesium nemamethecum strain but it did not cross-react with P. parvum...

  10. High false-positive rate of human immunodeficiency virus rapid serum screening in a predominantly hispanic prenatal population.

    Science.gov (United States)

    Zacharias, Nikolaos M; Athanassaki, Ioanna D; Sangi-Haghpeykar, Haleh; Gardner, Michael O

    2004-12-01

    To identify the characteristics of the gravidas delivering at our birthing center that place them at risk for false-positive human immunodeficiency virus (HIV) enzyme-linked immunosorbent assay (ELISA). The medical records of all rapid HIV-ELISA-positive gravidas that delivered at our hospital between January 2000 and October 2001 were retrieved, and information was gathered regarding maternal demographics. The results of the Western blot tests were also retrieved and correlated to the ELISA results, across varying maternal characteristics. chi(2), Student's t-test and multivariate analysis were performed, as appropriate, using the SAS software; statistical significance was denoted by ppositive rapid HIV-ELISA out of 9,781 deliveries. Of those, 26 were confirmed as HIV infected by Western blot (overall HIV prevalence: 0.27%, ELISA-positive predictive value: 37.7%). The subgroup prevalence of HIV and positive predictive value of ELISA were 1.53 and 75% among Caucasians; 2.43 and 82.6% among African-Americans; and 0.05 and 9.8% among Hispanics, respectively (p or =5 lifetime) sexual partners was elicited in the majority of HIV-infected patients. The positive predictive value of rapid HIV-ELISA during pregnancy varies widely, depending on maternal race/ethnicity and sexual behavior. The routine disclosure of rapid intrapartum HIV serum screening results prior to Western blot confirmation should be avoided in very low-risk populations.

  11. A lab-on-a-chip device for rapid identification of avian influenza viral RNA by solid-phase PCR

    DEFF Research Database (Denmark)

    Yi, Sun; Dhumpa, Raghuram; Bang, Dang Duong

    2011-01-01

    This paper describes a lab-on-a-chip device for fast AIV screening by integrating DNA microarray-based solid-phase PCR on a microfluidic chip.......This paper describes a lab-on-a-chip device for fast AIV screening by integrating DNA microarray-based solid-phase PCR on a microfluidic chip....

  12. Phases and rates of iron and magnetism changes during paddy soil development on calcareous marine sediment and acid Quaternary red-clay.

    Science.gov (United States)

    Huang, Laiming; Jia, Xiaoxu; Shao, Ming'an; Chen, Liumei; Han, Guangzhong; Zhang, Ganlin

    2018-01-11

    Dynamic changes in Fe oxides and magnetic properties during natural pedogenesis are well documented, but variations and controls of Fe and magnetism changes during anthropedogenesis of paddy soils strongly affected by human activities remain poorly understood. We investigated temporal changes in different Fe pools and magnetic parameters in soil profiles from two contrasting paddy soil chronosequences developed on calcareous marine sediment and acid Quaternary red clay in Southern China to understand the directions, phases and rates of Fe and magnetism evolution in Anthrosols. Results showed that paddy soil evolution under the influence of artificial submergence and drainage caused changes in soil moisture regimes and redox conditions with both time and depth that controlled Fe transport and redistribution, leading to increasing profile differentiation of Fe oxides, rapid decrease of magnetic parameters, and formation of diagnostic horizons and features, irrespective of the different parent materials. However, the initial parent material characteristics (pH, Fe content and composition, weathering degree and landscape positions) exerted a strong influence on the rates and trajectories of Fe oxides evolution as well as the phases and rates of magnetism changes. This influence diminished with time as prolonged rice cultivation drove paddy soil evolving to common pedogenic features.

  13. Microscopic evaluation of aqueous two-phase system emulsion characteristics enables rapid determination of critical polymer concentrations for solution micropatterning.

    Science.gov (United States)

    Ruthven, Mackenzie; Ko, Kristin Robin; Agarwal, Rishima; Frampton, John P

    2017-05-30

    Aqueous two-phase systems have emerged as valuable tools for microscale analysis of cell growth and many other biotechnology applications. The most critical step in developing an aqueous two-phase system for a specific application is identifying the critical concentrations at which the polymer solutions phase-separate. Current techniques for determining these critical concentrations rely on laborious methods, highly specialized assays or computational methods that make this step difficult for non-specialists. To overcome these limitations, we present a simplified assay that uses only readily accessible laboratory instruments and consumables (e.g., multichannel micropipettes, 96-well plates and a simple compound microscope) to determine the critical concentrations of aqueous two-phase system-forming polymers. We demonstrate that formulations selected from phase diagrams that describe these critical concentrations can be applied for solution micropatterning of cells.

  14. Bit-rate-transparent optical RZ-to-NRZ format conversion based on linear spectral phase filtering

    DEFF Research Database (Denmark)

    Maram, Reza; Da Ros, Francesco; Guan, Pengyu

    2017-01-01

    We propose a novel and strikingly simple design for all-optical bit-rate-transparent RZ-to-NRZ conversion based on optical phase filtering. The proposed concept is experimentally validated through format conversion of a 640 Gbit/s coherent RZ signal to NRZ signal.......We propose a novel and strikingly simple design for all-optical bit-rate-transparent RZ-to-NRZ conversion based on optical phase filtering. The proposed concept is experimentally validated through format conversion of a 640 Gbit/s coherent RZ signal to NRZ signal....

  15. Polarization states encoded by phase modulation for high bit rate quantum key distribution

    Science.gov (United States)

    Liu, Xiaobao; Tang, Zhilie; Liao, Changjun; Lu, Yiqun; Zhao, Feng; Liu, Songhao

    2006-10-01

    We present implementation of quantum cryptography with polarization code by wave-guide type phase modulator. At four different low input voltages of the phase modulator, coder encodes pulses into four different polarization states, 45°, 135° linearly polarized or right, left circle polarized, while the decoder serves as the complementary polarizers.

  16. Rapid in-focus corrections on quantitative amplitude and phase imaging using transport of intensity equation method.

    Science.gov (United States)

    Meng, X; Tian, X; Kong, Y; Sun, A; Yu, W; Qian, W; Song, X; Cui, H; Xue, L; Liu, C; Wang, S

    2017-06-01

    Transport of intensity equation (TIE) method can acquire sample phase distributions with high speed and accuracy, offering another perspective for cellular observations and measurements. However, caused by incorrect focal plane determination, blurs and halos are induced, decreasing resolution and accuracy in both retrieved amplitude and phase information. In order to obtain high-accurate sample details, we propose TIE based in-focus correction technique for quantitative amplitude and phase imaging, which can locate focal plane and then retrieve both in-focus intensity and phase distributions combining with numerical wavefront extraction and propagation as well as physical image recorder translation. Certified by both numerical simulations and practical measurements, it is believed the proposed method not only captures high-accurate in-focus sample information, but also provides a potential way for fast autofocusing in microscopic system. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  17. Rapid protein disappearance rates along the small intestine advantage poultry performance and influence the post-enteral availability of amino acids.

    Science.gov (United States)

    Truong, Ha H; Chrystal, Peter V; Moss, Amy F; Selle, Peter H; Liu, Sonia Yun

    2017-12-01

    A foundation diet, an intermediate blend and a summit diet were formulated with different levels of soyabean meal, casein and crystalline amino acids to compare 'slow' and 'rapid' protein diets. The diets were offered to male Ross 308 chicks from 7 to 28 d post-hatch and assessed parameters included growth performance, nutrient utilisation, apparent digestibility coefficients and disappearance rates of starch and protein (N) in four small intestinal segments. Digestibility coefficients and disappearance rates of sixteen amino acids in three small intestinal segments and amino acid concentrations in plasma from portal and systemic circulations from the foundation and summit diets were determined. The dietary transition significantly accelerated protein (N) disappearance rates in the distal jejunum and ileum. The transition from foundation to summit diets significantly increased starch digestibility coefficients in the ileum and disappearance rates in all four small intestinal segments. These starch responses were associated with significant enhancements in nutrient utilisation. The dietary transition linearly increased digestibility coefficients and disappearance rates of amino acids in the majority of cases. The summit diet increased plasma concentrations of five amino acids but decreased those of four amino acids relative to the foundation diet to significant extents. Plasma concentrations of free amino acids were higher in the portal than systemic circulations. Rapid protein disappearance rates advantaged poultry performance and influenced post-enteral availability of amino acids. If the underlying mechanisms are to be identified, further research into the impact of protein digestive dynamics on broiler performance is required but appears justified.

  18. A method to enhance the data transfer rate of eutectic Sb-Te phase-change recording media

    Science.gov (United States)

    Yeh, Tung-Ti; Hsieh, T.-E.; Shieh, Han-Ping D.

    2005-07-01

    This work describes the effect of nitrogen doping to eutectic Sb-Te phase-change materials in order to enhance the speed of the amorphous-to-crystalline phase transformation. When nitrogen at a sputtering gas flow ratio of N2/Ar=3% was doped in the eutectic Ge-In-Sb-Te recording layer, the data transfer rate was increased up to 1.6 times. When thin GeNx nucleation promotion layers were further added in below and above the recording layer, an overall enhancement up to 3.3 times in data transfer rate was achieved. The nitrogen contents corresponding to the N2/Ar flow ratios (N2/Ar=0%-10%) were calibrated by electron spectroscopy for chemical analysis. Transmission electron microscopy revealed that nitrogen doping was able to promote the phase transformation by generating numerous nucleation sites uniformly distributed in the recording layer and hence increased the recrystallization speed.

  19. The effect of coarse second-phase particles on the rate of grain refinement during severe deformation processing

    DEFF Research Database (Denmark)

    Apps, P.J.; Bowen, Jacob R.; Prangnell, P.B.

    2003-01-01

    The effect of second-phase particles on the rate of grain refinement during severe deformation processing has been investigated, by comparing the microstructure evolution in an AA8079 aluminium alloy, containing 2.5 vol.% of ~2 μm particles, with that in a high purity, single-phase, Al-0.13% Mg...... alloy, deformed identically by ECAE to an effective strain of ten. The materials were analysed by high-resolution EBSD orientation mapping, which revealed that grain refinement occurred at a dramatically higher rate in the particle-containing alloy. A submicron grain structure could be achieved...... by an effective strain of only five in the particle-containing alloy, compared to ten in the single-phase material. The mechanisms that contribute to this acceleration of the grain refinement process are discussed....

  20. Effect of acidified sorbate solutions on the lag phase durations and growth rates of Listeria monocytogenes on meat surfaces

    Science.gov (United States)

    The surfaces of ready-to-eat meats are susceptible to post-processing contamination by Listeria monocytogenes. This study quantified the lag phase durations (LPD) and growth rates (GR) of L. monocytogenes on the surfaces of cooked ham as affected by sorbate solutions of different concentrations and...

  1. 313 MHz repetition rate mode-locked Yb:fiber laser with phase-biased nonlinear amplifying loop mirror

    Science.gov (United States)

    Liu, Guanyu; Jiang, Xinghe; Wang, Bo; Jiang, Tongxiao; Wang, Aimin; Zhang, Zhigang

    2017-08-01

    We demonstrate a self-starting 313 MHz repetition rate, 77 fs Yb:fiber laser incorporated with a phase-biased nonlinear amplifying loop mirror and intra-cavity dispersion compensation. Although all of the fibers are non-polarization-maintaining, the mode locking is environmentally stable.

  2. Phase-amplitude characterization of a high-repetition-rate quantum dash passively mode-locked laser.

    Science.gov (United States)

    Gosset, C; Merghem, K; Moreau, G; Martinez, A; Aubin, G; Oudar, J-L; Ramdane, A; Lelarge, F

    2006-06-15

    We apply a novel phase-amplitude characterization method to a one-section quantum dash-based passively mode-locked laser at a 42.2 GHz repetition rate. The method relies on the measurement of the spectral phase of the longitudinal modes by the successive analysis of the correlation signal of a group of three adjacent modes. It provides both the temporal shape of the intensity and the phase of the emitted signal. A pulse of 1.5 ps of width is measured, and a pedestal is exhibited. Extinction ratio limitation is explained by investigating the origin of this pedestal. The accuracy of the method is estimated by comparing the measured autocorrelation signal and the calculated one from the phase analysis.

  3. A Multi-Band Photonic Phased Array Antenna for High-Data Rate Communication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Multi-band phased array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. In order to steer...

  4. A Multi-band Photonic Phased Array Antenna for High-Date Rate Communication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Multi-band phased array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. In order to steer...

  5. Phase resetting of the mammalian circadian clock relies on a rapid shift of a small population of pacemaker neurons.

    Directory of Open Access Journals (Sweden)

    Jos H T Rohling

    Full Text Available The circadian pacemaker of the suprachiasmatic nuclei (SCN contains a major pacemaker for 24 h rhythms that is synchronized to the external light-dark cycle. In response to a shift in the external cycle, neurons of the SCN resynchronize with different pace. We performed electrical activity recordings of the SCN of rats in vitro following a 6 hour delay of the light-dark cycle and observed a bimodal electrical activity pattern with a shifted and an unshifted component. The shifted component was relatively narrow as compared to the unshifted component (2.2 h and 5.7 h, respectively. Curve fitting and simulations predicted that less than 30% of the neurons contribute to the shifted component and that their phase distribution is small. This prediction was confirmed by electrophysiological recordings of neuronal subpopulations. Only 25% of the neurons exhibited an immediate shift in the phase of the electrical activity rhythms, and the phases of the shifted subpopulations appeared significantly more synchronized as compared to the phases of the unshifted subpopulations (p<0.05. We also performed electrical activity recordings of the SCN following a 9 hour advance of the light-dark cycle. The phase advances induced a large desynchrony among the neurons, but consistent with the delays, only 19% of the neurons peaked at the mid of the new light phase. The data suggest that resetting of the central circadian pacemaker to both delays and advances is brought about by an initial shift of a relatively small group of neurons that becomes highly synchronized following a shift in the external cycle. The high degree of synchronization of the shifted neurons may add to the ability of this group to reset the pacemaker. The large desynchronization observed following advances may contribute to the relative difficulty of the circadian system to respond to advanced light cycles.

  6. Rapid ice unloading in the Fleming Glacier region, southern Antarctic Peninsula, and its effect on bedrock uplift rates

    DEFF Research Database (Denmark)

    Zhao, Chen; King, Matt A.; Watson, Christopher S.

    2017-01-01

    m at the front of Fleming Glacier. Using IceBridge and ICESat-2/GLAS data spanning 2002–2014, we show an increased rate of mean ice-surface lowering, with rates post-2008 more than twice those of 2002–2008. We use these load change data as a basis for the simulation of viscoelastic solid Earth...... deformation. We subtract modeled elastic deformation rates, and a suite of modeled viscous rates, from GPS-derived three-dimensional bedrock velocities at sites to the south of Fleming Glacier to infer properties of Earth rheology. Assuming the pre-breakup bedrock uplift was positive due to post-Last Glacial...... the Fleming Glacier, after the application of elastic and plate tectonic corrections, point away from Marguerite Bay rather than the present glacier front. This suggests that horizontal motion in the region reflects the earlier retreat of the glacier system following the LGM, compatible with a relatively...

  7. Effect of solidification rate on microstructure evolution in dual phase microalloyed steel

    Science.gov (United States)

    Kostryzhev, A. G.; Slater, C. D.; Marenych, O. O.; Davis, C. L.

    2016-10-01

    In steels the dependence of ambient temperature microstructure and mechanical properties on solidification rate is not well reported. In this work we investigate the microstructure and hardness evolution for a low C low Mn NbTi-microalloyed steel solidified in the cooling rate range of 1-50 Cs-1. The maximum strength was obtained at the intermediate solidification rate of 30 Cs-1. This result has been correlated to the microstructure variation with solidification rate.

  8. Effect of solidification rate on microstructure evolution in dual phase microalloyed steel.

    Science.gov (United States)

    Kostryzhev, A G; Slater, C D; Marenych, O O; Davis, C L

    2016-10-19

    In steels the dependence of ambient temperature microstructure and mechanical properties on solidification rate is not well reported. In this work we investigate the microstructure and hardness evolution for a low C low Mn NbTi-microalloyed steel solidified in the cooling rate range of 1-50 Cs-1. The maximum strength was obtained at the intermediate solidification rate of 30 Cs-1. This result has been correlated to the microstructure variation with solidification rate.

  9. Use of peak decay analysis and affinity microcolumns containing silica monoliths for rapid determination of drug-protein dissociation rates.

    Science.gov (United States)

    Yoo, Michelle J; Hage, David S

    2011-04-15

    This report examined the use of silica monoliths in affinity microcolumns containing human serum albumin (HSA) to measure the dissociation rates for various drugs from this protein. Immobilized HSA and control monolith columns with dimensions of 1 mm × 4.6 mm i.d. were prepared for this work and used with a noncompetitive peak decay method. Several drugs known to bind HSA were examined, such as warfarin, diazepam, imipramine, acetohexamide, and tolbutamide. Items that were studied and optimized in this method included the sample volume, sample concentration, and elution flow rate. It was found that flow rates up to 10 mL/min could be used in this approach. Work with HSA silica monoliths at these high flow rates made it possible to provide dissociation rate constants for drugs such as warfarin in less than 40s. The dissociation rate constants that were measured gave good agreement with values reported in the literature or that had been obtained with other solutes that had similar binding affinities for HSA. This approach is a general one that should be useful in examining the dissociation of other drugs from HSA and in providing a high-throughput method for screening drug-protein interactions. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Rapid quantification of viable Legionella in nuclear cooling tower waters using filter cultivation, fluorescent in situ hybridization and solid-phase cytometry.

    Science.gov (United States)

    Baudart, J; Guillaume, C; Mercier, A; Lebaron, P; Binet, M

    2015-05-01

    To develop a rapid and sensitive method to quantify viable Legionella spp. in cooling tower water samples. A rapid, culture-based method capable of quantifying as few as 600 Legionella microcolonies per litre within 2 days in industrial waters was developed. The method combines a short cultivation step of microcolonies on GVPC agar plate, specific detection of Legionella cells by a fluorescent in situ hybridization (FISH) approach, and a sensitive enumeration using a solid-phase cytometer. Following optimization of the cultivation conditions, the qualitative and quantitative performance of the method was assessed and the method was applied to 262 nuclear power plant cooling water samples. The performance of this method was in accordance with the culture method (NF-T 90-431) for Legionella enumeration. The rapid detection of viable Legionella in water is a major concern to the effective monitoring of this pathogenic bacterium in the main water sources involved in the transmission of legionellosis infection (Legionnaires' disease). The new method proposed here appears to be a robust, efficient and innovative means for rapidly quantifying cultivable Legionella in cooling tower water samples within 48 h. © 2015 The Society for Applied Microbiology.

  11. Linear free energy relationships between aqueous phase hydroxyl radical reaction rate constants and free energy of activation.

    Science.gov (United States)

    Minakata, Daisuke; Crittenden, John

    2011-04-15

    The hydroxyl radical (HO(•)) is a strong oxidant that reacts with electron-rich sites on organic compounds and initiates complex radical chain reactions in aqueous phase advanced oxidation processes (AOPs). Computer based kinetic modeling requires a reaction pathway generator and predictions of associated reaction rate constants. Previously, we reported a reaction pathway generator that can enumerate the most important elementary reactions for aliphatic compounds. For the reaction rate constant predictor, we develop linear free energy relationships (LFERs) between aqueous phase literature-reported HO(•) reaction rate constants and theoretically calculated free energies of activation for H-atom abstraction from a C-H bond and HO(•) addition to alkenes. The theoretical method uses ab initio quantum mechanical calculations, Gaussian 1-3, for gas phase reactions and a solvation method, COSMO-RS theory, to estimate the impact of water. Theoretically calculated free energies of activation are found to be within approximately ±3 kcal/mol of experimental values. Considering errors that arise from quantum mechanical calculations and experiments, this should be within the acceptable errors. The established LFERs are used to predict the HO(•) reaction rate constants within a factor of 5 from the experimental values. This approach may be applied to other reaction mechanisms to establish a library of rate constant predictions for kinetic modeling of AOPs.

  12. Significance of vapor phase chemical reactions on CVD rates predicted by chemically frozen and local thermochemical equilibrium boundary layer theories

    Science.gov (United States)

    Gokoglu, Suleyman A.

    1988-01-01

    This paper investigates the role played by vapor-phase chemical reactions on CVD rates by comparing the results of two extreme theories developed to predict CVD mass transport rates in the absence of interfacial kinetic barrier: one based on chemically frozen boundary layer and the other based on local thermochemical equilibrium. Both theories consider laminar convective-diffusion boundary layers at high Reynolds numbers and include thermal (Soret) diffusion and variable property effects. As an example, Na2SO4 deposition was studied. It was found that gas phase reactions have no important role on Na2SO4 deposition rates and on the predictions of the theories. The implications of the predictions of the two theories to other CVD systems are discussed.

  13. Phase-stable single-pass cryogenic amplifier for high repetition rate few-cycle laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Akira; Schneider, Waldemar; Haensch, Theodor W; Udem, Thomas; Hommelhoff, Peter [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D 85748 Garching (Germany)], E-mail: akira.ozawa@mpq.mpg.de, E-mail: peter.hommelhoff@mpq.mpg.de

    2009-08-15

    We demonstrate cryogenic Ti:sapphire single-pass amplification of sub-7 fs laser pulses with 80 MHz repetition rate. We amplify the output of a broadband Ti:sapphire oscillator by more than a factor of two, re-compress the pulses down to sub-7 fs, and show that the rms carrier-envelope phase jitter stays below 70 as after amplification. The amplified output exceeds 2 MW of peak power and 1 W of average power. In addition, we demonstrate amplification of {approx}200 fs, 75 MHz oscillator pulses up to 1.6 W with a gain of four. This work opens a new way to explore phase sensitive and highly nonlinear phenomena at the full oscillator repetition rate. As a first example, we demonstrate white light generation in a bulk crystal at the full oscillator repetition rate.

  14. Liquid Phase Separation and the Aging Effect on Mechanical and Electrical Properties of Laser Rapidly Solidified Cu100−xCrx Alloys

    Directory of Open Access Journals (Sweden)

    Song-Hua Si

    2015-11-01

    Full Text Available Duplex structure Cu-Cr alloys are widely used as contact materials. They are generally designed by increasing the Cr content for the hardness improvement, which, however, leads to the unfavorable rapid increase of the electrical resistivity. The solidification behavior of Cu100−xCrx (x = 4.2, 25 and 50 in wt.% alloys prepared by laser rapid solidification is studied here, and their hardness and electrical conductivity after aging are measured. The results show that the Cu-4.2%Cr alloy has the most desirable combination of hardness and conductive properties after aging in comparison with Cu-25%Cr and Cu-50%Cr alloys. Very importantly, a 50% improvement in hardness is achieved with a simultaneous 70% reduction in electrical resistivity. The reason is mainly attributed to the liquid phase separation occurring in the Cu-4.2%Cr alloy, which introduces a large a

  15. Microstructure and Phase Formation in a Rapidly Solidified Laser-Deposited Ni-Cr-B-Si-C Hardfacing Alloy

    NARCIS (Netherlands)

    Hemmati, Ismail; Ocelik, Vaclav; Csach, Kornel; de Hosson, Jeff Th M.

    In this study, microstructural evolutions and phase selection phenomena during laser deposition of a hardfacing Ni-Cr-B-Si-C alloy at different processing conditions are experimentally investigated. The results show that even minor variations in the thermal conditions during solidification can

  16. Clinical follow-up data and the rate of development of precocious and rapidly progressive puberty in patients with premature thelarche.

    Science.gov (United States)

    Çiçek, Dilek; Savas-Erdeve, Senay; Cetinkaya, Semra; Aycan, Zehra

    2018-01-26

    We aimed to evaluate the clinical follow-up data of patients with premature thelarche and determine the rate of development of precocious and early puberty in these patients. The charts of 158 girls with premature thelarche who were followed-up in our pediatric endocrinology polyclinic were reviewed. The patients were divided into three groups according to the age at onset: group 1 (0-1 month) (n=12), group 2 (1-24 months) (n=40) and group 3 (2-8 years) (n=106). At admission, the mean height standard deviation score (SDS), body weight (BW)-SDS, body mass index (BMI) and BMI-SDS were significantly higher in group 3 than in group 1 and group 2. At admission, 8.8% of the patients were obese and 24% of the patients were overweight. The majority of patients who were obese and overweight were in group 3. At the end of the follow-up, thelarche regressed in 24.7%, persisted in 32.9%, progressed in 25.9% and had a cyclic pattern in 16.5% of the patients. Precocious or rapidly progressive puberty developed in 47 of the 158 patients (29.7%). The mean age at progression to early or rapidly progressive puberty was 98.1±17.6 months. A total of 89.3% of the patients who progressed to early or rapidly progressive puberty were in group 3. Precocious or rapidly progressive puberty developed in 29.7% of subjects with premature thelarche. As patients who developed rapidly progressive puberty had a higher BW-SDS and BMI-SDS than those who did not, it is suggested that the increase in weight could stimulate rapidly progressive puberty in cases with premature thelarche.

  17. A lab-on-a-chip device for rapid identification of avian influenza viral RNA by solid-phase PCR.

    Science.gov (United States)

    Sun, Yi; Dhumpa, Raghuram; Bang, Dang Duong; Høgberg, Jonas; Handberg, Kurt; Wolff, Anders

    2011-04-21

    The endemic of Avian Influenza Virus (AIV) in Asia and epizootics in some European regions have caused serious economic losses. Multiplex reverse-transcriptase (RT) PCR has been developed to detect and subtype AIV. However, the number of targets that can be amplified in a single run is limited because of uncontrollable primer-primer interferences. In this paper, we describe a lab-on-a-chip device for fast AIV screening by integrating DNA microarray-based solid-phase PCR on a microfluidic chip. A simple UV cross-linking method was used to immobilize the DNA probes on unmodified glass surface, which makes it convenient to integrate microarray with microfluidics. This solid-phase RT-PCR method combined RT amplification of extracted RNA in the liquid phase and species-specific nested PCR on the solid phase. Using the developed approach, AIV viruses and their subtypes were unambiguously identified by the distinct patterns of amplification products. The whole process was reduced to less than 1 hour and the sample volume used in the microfluidic chip was at least 10 times less than in the literature. By spatially separating the primers, highly multiplexed amplification can be performed in solid-phase PCR. Moreover, multiplex PCR and sequence detection were done in one step, which greatly simplified the assay and reduced the processing time. Furthermore, by incorporating the microarray into a microchamber-based PCR chip, the sample and the reagent consumption were greatly reduced, and the problems of bubble formation and solution evaporation were effectively prevented. This microarray-based PCR microchip can be widely employed for virus detection and effective surveillance in wild avian and in poultry productions.

  18. Nonconserved Residues Ala287 and Ser290 of the Cryptosporidium hominis Thymidylate Synthase Domain Facilitate Its Rapid Rate of Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Doan,L.; Martucci, W.; Vargo, M.; Atreya, C.; Anderson, K.

    2007-01-01

    Cryptosporidium hominis TS-DHFR exhibits an unusually high rate of catalysis at the TS domain, at least 10-fold greater than those of other TS enzymes. Using site-directed mutagenesis, we have mutated residues Ala287 and Ser290 in the folate-binding helix to phenylalanine and glycine, respectively, the corresponding residues in human and most other TS enzymes. Our results show that the mutant A287F, the mutant S290G, and the double mutant all have reduced affinities for methylene tetrahydrofolate and reduced rates of reaction at the TS domain. Interestingly, the S290G mutant enzyme had the lowest TS activity, with a catalytic efficiency {approx}200-fold lower than that of the wild type (WT). The rate of conformational change of the S290G mutant is {approx}80 times slower than that of WT, resulting in a change in the rate-limiting step from hydride transfer to covalent ternary complex formation. We have determined the crystal structure of ligand-bound S290G mutant enzyme, which shows that the primary effect of the mutation is an increase in the distance between the TS ligands. The kinetic and crystal structure data presented here provide the first evidence explaining the unusually fast TS rate in C. hominis.

  19. Perceptual and Cognitive Factors Imposing "Speed Limits" on Reading Rate: A Study with the Rapid Serial Visual Presentation.

    Directory of Open Access Journals (Sweden)

    Silvia Primativo

    Full Text Available Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm. This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR. In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm. Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate.

  20. Perceptual and Cognitive Factors Imposing "Speed Limits" on Reading Rate: A Study with the Rapid Serial Visual Presentation.

    Science.gov (United States)

    Primativo, Silvia; Spinelli, Donatella; Zoccolotti, Pierluigi; De Luca, Maria; Martelli, Marialuisa

    2016-01-01

    Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate.

  1. Rapid progression of gliomatosis cerebri to secondary glioblastoma, factors that affects the progression rate: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee Kyung; Yu, In Kyu; Kim, Seung Min; Kim, Joo Heon; Lee, Seung Hoon; Lee, Seung Yeon [Eulji University Hospital, Daejeon (Korea, Republic of)

    2017-03-15

    Glioblastomas may develop de novo or through progression from low-grade or anaplastic astrocytomas. The term 'primary glioblastoma' refers to a glioblastoma that lacks a precursor lesion and has a clinical history of less than three months. On the other hand, the term 'secondary glioblastoma' indicates that the glioblastoma has progressed from a low-grade tumor after a long latency period and often manifests in younger patients. These subtypes of glioblastoma develop via different genetic pathways, and they differ in prognosis and response to therapy. Thus, differential diagnosis of these subtypes and prediction of the factors that affect the progression from low-grade diffuse astrocytoma to secondary glioblastoma would be clinically very important. We present a rare case of secondary glioblastoma, which developed only three months after the follow up imaging evaluations, with a history of low grade glioma, and present the factors that cause rapid progression.

  2. Dynamic solid phase microextraction for sampling of airborne sarin with gas chromatography-mass spectrometry for rapid field detection and quantification.

    Science.gov (United States)

    Hook, Gary L; Jackson Lepage, Carmela; Miller, Stephen I; Smith, Philip A

    2004-08-01

    A portable dynamic air sampler and solid phase microextraction were used to simultaneously detect, identify, and quantify airborne sarin with immediate analysis of samples using a field portable gas chromatography-mass spectrometry system. A mathematical model was used with knowledge of the mass of sarin trapped, linear air velocity past the exposed sampling fiber, and sample duration allowing calculation of concentration estimates. For organizations with suitable field portable instrumentation, these methods are potentially useful for rapid onsite detection and quantification of high concern analytes, either through direct environmental sampling or through sampling of air collected in bags.

  3. Numerical simulation for a two-phase porous medium flow problem with rate independent hysteresis

    KAUST Repository

    Brokate, M.

    2012-05-01

    The paper is devoted to the numerical simulation of a multiphase flow in porous medium with a hysteretic relation between the capillary pressures and the saturations of the phases. The flow model we use is based on Darcys law. The hysteretic relation between the capillary pressures and the saturations is described by a play-type hysteresis operator. We propose a numerical algorithm for treating the arising system of equations, discuss finite element schemes and present simulation results for the case of two phases. © 2011 Elsevier B.V. All rights reserved.

  4. Rapid Prototyping

    Science.gov (United States)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  5. Structure and phase transformations in copper-alloyed rapidly melt-quenched Ni50Ti32Hf18-based alloys with high-temperature shape memory effect

    Science.gov (United States)

    Pushin, A. V.; Pushin, V. G.; Kuranova, N. N.; Kourov, N. I.; Kuntsevich, T. E.; Makarov, V. V.; Uksusnikov, A. N.

    2017-10-01

    Methods of transmission and scanning electron microscopy, chemical microanalysis, electron diffraction, and X-ray diffraction have been used to carry out the comparative study of the structure and chemical and phase composition of thin ribbons of four quasi-binary alloys (Ni50Ti32Hf18, Ni45Ti32Hf18Cu5, Ni35Ti32Hf18Cu15, and Ni25Ti32Hf18Cu25) obtained in the amorphous state by rapid quenching from the melt by jet spinning. The critical temperatures of the devitrification and B2 ↔ B19' martensitic transformation of the alloys have been determined based on the data of temperature dependences of the electrical resistivity. The specific features of the formation of the ultrafine-grained structure upon the devitrification and of the phase transformations have been studied depending on the heat-treatment regimes and chemical composition of the alloys (concentration of copper atoms).

  6. Chronic Subdural Hematoma development in Accelerated phase of Chronic Myeloid Leukaemia presenting with seizure and rapid progression course with fatal outcome

    Directory of Open Access Journals (Sweden)

    Raheja Amol

    2015-06-01

    Full Text Available Occurrence of chronic subdural hematoma (CSDH in leukemia is rare, and most reported cases occurred in relation with acute myeloid leukaemia; however, occurrence is extremely rare in accelerated phase of chronic myelogenous leukaemia (CML. Seizure as presentation of SDH development in CML cases is not reported in literature. Authors report an elderly male, who was diagnosed as CML, accelerated phase of developing SDH. Initially presented to local physician with seizure; urgent CT scan head was advised, but ignored and sensorium rapidly worsened over next day and reported to our emergency department in deeply comatose state, where imaging revealed chronic subdural hematoma with hypoxic brain injury with fatal outcome. Seizure, progressive worsening of headache, vomiting and papilloedema are harbinger of intracranial space occupying lesion and requires CT head in emergency medical department for exclusion, who are receiving treatment of haematological malignancy

  7. Isocratic Solid Phase Extraction-Liquid Chromatography (SPE-LC) Interfaced to High-Performance Tandem Mass Spectrometry for Rapid Protein Identification

    DEFF Research Database (Denmark)

    Hørning, Ole B; Kjeldsen, Frank; Theodorsen, Søren

    2008-01-01

    Reversed-phase liquid chromatography interfaced to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) allows analysis of very complex peptide mixtures at great sensitivity, but it can be very time-consuming, typically using 60 min, or more, per sample analysis. We recently introduced...... the isocratic solid phase extraction-liquid chromatography (SPE-LC) technology for rapid separation ( approximately 8 min) of simple peptide samples. We now extend these studies to demonstrate the potential of SPE-LC separation in combination with a hybrid linear ion trap-Orbitrap tandem mass spectrometer...... for efficient analysis of peptide samples in proteomics research. The system performance of SPE-LC-MS/MS was evaluated in terms of sensitivity and efficiency for the analysis of tryptic peptide digests obtained from samples consisting of up to 12 standard proteins. The practical utility of the analytical setup...

  8. First-pass intubation success rate during rapid sequence induction of prehospital anaesthesia by physicians versus paramedics

    NARCIS (Netherlands)

    Peters, J.H.; Wageningen, B. van; Hendriks, I.; Eijk, R.J.R.; Edwards, M.J.; Hoogerwerf, N.; Biert, J.

    2015-01-01

    INTRODUCTION: Endotracheal intubation is a frequently performed procedure for securing the airway in critically injured or ill patients. Performing prehospital intubation may be challenging and intubation skills vary. We reviewed the first-attempt tracheal intubation success rate in a Dutch

  9. From Expressive Reading to Rapid Reading: The Rise in Reading Rate During the Efficiency Movement (1910-1925)

    Science.gov (United States)

    Taylor, Laura A.

    2015-01-01

    Reading rate, a component of reading not closely attended to by educators and researchers prior to the 20th century, quickly became the subject of considerable research shortly after the turn of the century. This article uses historical content analysis to examine primary source documents from that period (1910-1925) to explore why reading rate…

  10. A Laboratory to Demonstrate the Effect of Thermal History on Semicrystalline Polymers Using Rapid Scanning Rate Differential Scanning Calorimetry

    Science.gov (United States)

    Badrinarayanan, Prashanth; Kessler, Michael R.

    2010-01-01

    A detailed understanding of the effect of thermal history on the thermal properties of semicrystalline polymers is essential for materials scientists and engineers. In this article, we describe a materials science laboratory to demonstrate the effect of parameters such as heating rate and isothermal annealing conditions on the thermal behavior of…

  11. Rapid determination of alpha tocopherol in olive oil adulterated with sunflower oil by reversed phase high-performance liquid chromatography.

    Science.gov (United States)

    Bakre, S M; Gadmale, D K; Toche, R B; Gaikwad, V B

    2015-05-01

    A new method is developed to determine the presence of sunflower oil in olive oil. α-tocopherol is selected as discriminating parameter for detecting sunflower oil adulterant in olive oil. Admixtures of olive oil and sunflower oil (5 %, 10 %, 15 % and 20 % sunflower oil in olive oil) are prepared. These admixtures are analysed by reversed phase high pressure liquid chromatography coupled with fluorescence detector. The sample preparation does not require saponification or addition of antioxidant. The chromatographic system consists of a C18 column with methanol: acetonitrile (50:50) mobile phase. Fluorescence detector excitation wavelength is set at 290 nm and emission wavelength is set at 330 nm. The α tocopherol concentration increases linearly in olive oil adulterated with sunflower oil. The method is simple, selective, sensitive and is precise (RSD = 2.65 %) for α tocopherol. The present method can precisely detect 5 % sunflower oil in olive oil.

  12. Rate of Gas Phase Association of Hydroxyl Radical and Nitrogen Dioxide

    OpenAIRE

    Mollner, Andrew K.; Valluvadasan, Sivakumaran; Feng, Lin; Sprague, Matthew K.; Okumura, Mitchio; Milligan, Daniel B.; Bloss, William J.; Sander, Stanley P.; Martien, Philip T.; Harley, Robert A.; McCoy, Anne B.; Carter, William P. L.

    2010-01-01

    The reaction of OH and NO_2 to form gaseous nitric acid (HONO_2) is among the most influential in atmospheric chemistry. Despite its importance, the rate coefficient remains poorly determined under tropospheric conditions because of difficulties in making laboratory rate measurements in air at 760 torr and uncertainties about a secondary channel producing peroxynitrous acid (HOONO). We combined two sensitive laser spectroscopy techniques to measure the overall rate of both channels and the pa...

  13. Rapid determination of alpha tocopherol in olive oil adulterated with sunflower oil by reversed phase high-performance liquid chromatography

    OpenAIRE

    Bakre, S.M.; Gadmale, D. K.; Toche, R. B.; V. B. GAIKWAD

    2014-01-01

    A new method is developed to determine the presence of sunflower oil in olive oil. α-tocopherol is selected as discriminating parameter for detecting sunflower oil adulterant in olive oil. Admixtures of olive oil and sunflower oil (5 %, 10 %, 15 % and 20 % sunflower oil in olive oil) are prepared. These admixtures are analysed by reversed phase high pressure liquid chromatography coupled with fluorescence detector. The sample preparation does not require saponification or addition of antioxid...

  14. Rapid Quantification of the Toxic Alga Prymnesium parvum in Natural Samples by Use of a Specific Monoclonal Antibody and Solid-Phase Cytometry

    Science.gov (United States)

    West, N. J.; Bacchieri, R.; Hansen, G.; Tomas, C.; Lebaron, P.; Moreau, H.

    2006-01-01

    The increasing incidence of harmful algal blooms around the world and their associated health and economic effects require the development of methods to rapidly and accurately detect and enumerate the target species. Here we describe use of a solid-phase cytometer to detect and enumerate the toxic alga Prymnesium parvum in natural samples, using a specific monoclonal antibody and indirect immunofluorescence. The immunoglobulin G antibody 16E4 exhibited narrow specificity in that it recognized several P. parvum strains and a Prymnesium nemamethecum strain but it did not cross-react with P. parvum strains from Scandinavia or any other algal strains, including species of the closely related genus Chrysochromulina. Prymnesium sp. cells labeled with 16E4 were readily detected by the solid-phase cytometer because of the large fluorescence signal and the signal/noise ratio. Immunofluorescence detection and enumeration of cultured P. parvum cells preserved with different fixatives showed that the highest cell counts were obtained when cells were fixed with either glutaraldehyde or formaldehyde plus the cell protectant Pluronic F-68, whereas the use of formaldehyde alone resulted in significantly lower counts. Immunofluorescence labeling and analysis with the solid-phase cytometer of fixed natural samples from a bloom of P. parvum occurring in Lake Colorado in Texas gave cell counts that were close to those obtained by the traditional method of counting using light microscopy. These results show that a solid-phase cytometer can be used to rapidly enumerate natural P. parvum cells and that it could be used to detect other toxic algae, with an appropriate antibody or DNA probe. PMID:16391128

  15. Rate Equation-Based Phase Recovery for Semiconductor Laser Coherent Transmitters

    DEFF Research Database (Denmark)

    Piels, Molly; Iglesias Olmedo, Miguel; Pang, Xiaodan

    2015-01-01

    We present a novel carrier recovery technique for coherent systems with semiconductor lasers that incorporates the laser dynamics. A sensitivity improvement of 8dB over a decision-directed phase-locked loop is achieved experimentally for 28GBd DP-16QAM....

  16. Rate of reaction of dimethylmercury with oxygen atoms in the gas phase

    DEFF Research Database (Denmark)

    Egsgaard, Helge

    1986-01-01

    The rate constant for the reaction of atomic oxygen (O(3P)) with dimethylmercury has been measured at room temperature at a pressure of about 1 Torr using a fast flow system with electron paramagnetic resonance and mass spectrometric detection. Some reaction products were identified. The rate...

  17. Magnetostriction of the rapidly quenched Co80Nb8B12 alloy: Dependence on quenching rate, structural relaxation, and temperature

    DEFF Research Database (Denmark)

    Madurga, V.; Barandiarán, J. M.; Vázquez, M.

    1987-01-01

    Ribbons of nominal composition Co80Nb8B12 have been prepared by the single roller quenching method using different wheel velocities ranging from 26 to 42 ms−1. X-ray diffraction patterns for ribbons prepared at low velocities show crystalline peaks but characteristic for the amorphous state...... for samples prepared at velocities above 36 ms−1. Room-temperature values of the magnetostriction constant lambdas depend on the quenching rate and changes from 4×10−7 to −1×10−6 as the wheel speed increases. Zero magnetostriction samples are obtained at about 34 ms−1. Thermal treatments change the values...... of the magnetostriction in the same way as a decrease in the quenching rate does. A dependence of the magnetostriction constant on the applied stress has been found. This dependence, fully reversible, is observed at room temperature. Journal of Applied Physics is copyrighted by The American Institute of Physics....

  18. The α →ɛ phase transition in iron at strain rates up to ˜109 s-1

    Science.gov (United States)

    Crowhurst, Jonathan C.; Reed, Bryan W.; Armstrong, Michael R.; Radousky, Harry B.; Carter, Jeffrey A.; Swift, Damian C.; Zaug, Joseph M.; Minich, Roger W.; Teslich, Nick E.; Kumar, Mukul

    2014-03-01

    We have used a table-top scale laser to dynamically compress iron at strain rates in excess of 109 s-1. Using an embedded ultrafast interferometer, we have measured corresponding free surface histories with a time resolution of approximately 10 ps. We have analyzed the surface histories using a method that accounts for nonsteady wave propagation and time-dependent material behavior. We show that at these strain rates, the α →ɛ polymorphic transition begins within 100 ps after an initial very large (˜10 GPa) and mostly elastic compression and appears largely complete within a similar time thereafter. The corresponding deviatoric stress before the transition begins can exceed 3 GPa, while the transition stress itself is up to 25 GPa, nearly twice the value measured at low strain rates. We use these results to propose a systematic variation with loading time of the normal-stress/relative-volume curve followed by iron during rapid compression.

  19. Crystal Phases Formed in a CaO-Fe2O3 System Under a High Cooling Rate in Air

    Science.gov (United States)

    Kashiwaya, Yoshiaki

    2017-10-01

    A CaO-Fe2O3 system is a fundamental binary system for the iron ore sintering process. Although the basic reactions have been investigated since the 1960s, melting and solidification caused by the combustion of coke results in an unstable state owing to extreme temperature variations. In this study, using a hot thermocouple method, samples of 10 pct CaO-90 pct Fe2O3 and 20 pct CaO-80 pct Fe2O3 were melted on a thermocouple and quenched with several techniques. The obtained samples were precisely examined by XRD. It was found that the sample containing 10 pct CaO-90 pct Fe2O3 changed to 10 pct CaO-13 pct FeO-77 pct Fe2O3 under an oxygen partial pressure ( P_{{{O}2 }} ) of 0.21 during melting. For the 10 pct CaO sample, the crystal phases found at a low cooling rate (509 K/s) were WFss, C4WF8 (C: CaO, W: FeO, F: Fe2O3), and C2W4F9. When the sample composition was 20 pct CaO, the precipitated crystal phases were C4WF4, C4F7, and C4WF8. On the other hand, the crystal phases for high cooling rates (1590 and 7900 K/s) with 10 pct CaO were WFss (solid solution of WF and F), F, and C2W4F9. The formation of the equilibrium phases WFss, F, C4WF4, and C4WF8 can be understood by examining the isothermal section of the phase diagrams, while the unstable phases C2W4F9 and C4F7 are discussed on the basis of the reactions under an equilibrium state.

  20. Crystal Phases Formed in a CaO-Fe2O3 System Under a High Cooling Rate in Air

    Science.gov (United States)

    Kashiwaya, Yoshiaki

    2017-12-01

    A CaO-Fe2O3 system is a fundamental binary system for the iron ore sintering process. Although the basic reactions have been investigated since the 1960s, melting and solidification caused by the combustion of coke results in an unstable state owing to extreme temperature variations. In this study, using a hot thermocouple method, samples of 10 pct CaO-90 pct Fe2O3 and 20 pct CaO-80 pct Fe2O3 were melted on a thermocouple and quenched with several techniques. The obtained samples were precisely examined by XRD. It was found that the sample containing 10 pct CaO-90 pct Fe2O3 changed to 10 pct CaO-13 pct FeO-77 pct Fe2O3 under an oxygen partial pressure ( P_{{{O}2 }} ) of 0.21 during melting. For the 10 pct CaO sample, the crystal phases found at a low cooling rate (509 K/s) were WFss, C4WF8 (C: CaO, W: FeO, F: Fe2O3), and C2W4F9. When the sample composition was 20 pct CaO, the precipitated crystal phases were C4WF4, C4F7, and C4WF8. On the other hand, the crystal phases for high cooling rates (1590 and 7900 K/s) with 10 pct CaO were WFss (solid solution of WF and F), F, and C2W4F9. The formation of the equilibrium phases WFss, F, C4WF4, and C4WF8 can be understood by examining the isothermal section of the phase diagrams, while the unstable phases C2W4F9 and C4F7 are discussed on the basis of the reactions under an equilibrium state.

  1. Rapid determination by reversed-phase high-performance liquid chromatography of Vitamins A and E in infant formulas.

    Science.gov (United States)

    Rodas Mendoza, B; Morera Pons, S; Castellote Bargalló, A I; López-Sabater, M C

    2003-11-14

    A rapid, sensitive method has been developed for the simultaneous determination of retinol acetate, delta-, gamma-, alpha-tocopherol and alpha-tocopherol acetate. We compare two experimental procedures for simultaneous direct solvent extraction of these vitamins without previous saponification. Method I: the fat milk sample was extracted with ethanol-hexane and injected directly into the chromatographic column. Method II: the power milk sample was extracted with ethanol-hexane and also injected directly into the column. Under optimum conditions the limits of detection for retinol acetate, delta-, gamma-, alpha-tocopherol and alpha-tocopherol acetate were 0.33, 21.2, 32.9, 32.5 and 3.2 ng and the limits of quantification were 0.42, 25.3, 37.9, 36.8 and 6.3 ng, respectively. The precision results showed that the relative standard deviations of repeatability and reproducibility were between 0.74 and 5.7%.

  2. Survival and progression rates of large European silver eel Anguilla anguilla in late freshwater and early marine phases

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Thorstad, Eva B.; Koed, Anders

    2010-01-01

    The population of European silver eel Anguilla anguilla has declined tremendously in the last decades. The cause of this decline is unknown, and it is necessary to investigate the migratory behaviour and survival rates of silver eels during the reproductive migration in order to understand...... was high in fresh water. However, 60% of eels were lost in the inner and outer fjord, supporting the hypothesis that mortality is large in the early phase of the marine migration and that fishing may be a major cause of mortality of silver eels. There was no indication that the slowest-migrating...... if the decline is related to factors acting during that migration. We estimated survival and progression rates of European silver eel migrating in the lower part of the River Gudenaa and during the first phase of the marine migration in the Randers Fjord in Denmark. Fifty migrating silver eel (total body length...

  3. Preparation of {sup 183,184}Re samples for modelling a rapid gas phase chemistry of Nielsbohrium (Ns), element 107

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, R.; Gaeggeler, H.W.; Eichler, B.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Chemical gas phase reactions of the heavier group 7 elements in the system O{sub 2}/H{sub 2}O are presumably best suited for a separation of Nielsbohrium from the lighter transactinides. We expect a higher reaction velocity using the more reactive gas system O{sub 3}/H{sub 2}O{sub 2}. For the experimental verification of this idea we prepared {sup 183}Re/{sup 184}Re samples for thermochromatography experiments with both gas systems. (author) 8 refs.

  4. Experimental investigation of effect of spacer on two phase turbulent mixing rate in subchannels of pressure tube type BWR

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Shashi Kant; Sinha, S.L. [National Institute of Technology, Raipur (India). Mechanical Engineering Dept.; Chandraker, D.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Design and Development Group

    2017-11-15

    Turbulent mixing rate between adjacent subchannels in a two-phase flow has been known to be strongly dependent on the flow pattern. The most important aspect of turbulent motion is that the velocity and pressure at a fixed point do not remain constant with time even in steady state but go through very irregular high frequency fluctuations. These fluctuations influence the diffusion of scalar and vector quantities. The Advanced Heavy Water Reactor (AHWR) is a vertical pressure tube type, heavy water moderated and boiling light water cooled natural circulation based reactor. The fuel bundle of AHWR contains 54 fuel rods set in three concentric rings of 12, 18 and 24 fuel rods. This fuel bundle is divided into number of imaginary interacting flow channel called subchannels. Alteration from single phase to two phase flow situation occurs in reactor rod bundle with raise in power. The two phase flow regimes like bubbly, slug-churn, and annular flow are generally encountered in reactor rod bundle. Prediction of thermal margin of the reactor has necessitated the investigation of turbulent mixing rate of coolant between these subchannels under these flow regimes. Thus, it is fundamental to estimate the effect of spacer grids on turbulent mixing between subchannels of AHWR rod bundle.

  5. Rapid Ag/Sn/Ag transient liquid phase bonding for high-temperature power devices packaging by the assistance of ultrasound.

    Science.gov (United States)

    Shao, Huakai; Wu, Aiping; Bao, Yudian; Zhao, Yue; Liu, Lei; Zou, Guisheng

    2017-07-01

    Rapid transient liquid phase (TLP) bonding process on Ag/Sn/Ag system is achieved in air by the assistance of ultrasonic, which has great potential to be applied to high-temperature power devices packaging. In this study, the influence of ultrasonic effect on the morphology and growth kinetics of Ag3Sn grains, and the joint microstructure, mechanical property and thermal reliability were systematically investigated. Experimental results indicated that the rapid consumption of the "dynamic" transient liquid phase was attributed to the accelerated dissolution of Ag substrate and the extrusion of liquid Sn, which were entirely induced by the complex sonochemical effects on the liquid/solid intermetallic compounds (IMCs) interface. An elongated scallop-like morphology of Ag3Sn grains was developed during Ag/Sn interfacial reaction with ultrasonic, accompanied by widening of grooves between neighbored grains. This phenomenon is called as a strengthening thermal grooving, in which the grooves at grain boundaries provide stable molten channels for Ag atoms diffusion from the substrate. Consequently, the improved elemental diffusion was evaluated through the growth kinetics of Ag3Sn IMCs, with conservative estimation of 6-16.5 times faster than the traditional TLP process. In addition, both excellent mechanical property and thermal reliability of the Ag-Sn intermetallic joint were experimentally verified by shear test and high-temperature storage test, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. In vivo biosynthesis of L-(/sup 35/S)Cys-arginine vasopressin, -oxytocin, and -somatostatin: rapid estimation using reversed phase high pressure liquid chromatography. [Rats

    Energy Technology Data Exchange (ETDEWEB)

    Franco-Bourland, R.E.; Fernstrom, J.D.

    1981-01-01

    L(/sup 35/S)Cys-arginine vasopressin, -oxytocin, and -somatostatin were purified from hypothalami and neurohypophyses 4 h after rats received L(/sup 35/S)Cys via the third ventricle. After acetic acid extraction, Sephadex G-25 filtration, and chemoadsorption to C18-silica (Sep-Pak cartridges), the labeled peptides were rapidly separated by gradient elution, reversed phase, high pressure liquid chromatography (HPLC). The identity and isotopic purity of the labeled peptides were determined by several reversed phase HPLC procedures in conjunction with chemical modification. The labeled peptide fractions were at least 50% radiochemically pure. Using this HPLC isolation procedure, incorporation of L-(/sup 35/S)Cys into each peptide was determined in hydrated and dehydrated rats. Label incorporation into arginine vasopressin and oxytocin in the hypothalamus and the neurohypophysis of dehydrated rats was 2-3 times greater than that in hydrated rats. Incorporation of label into hypothalamic and neurohypophyseal somatostatin was unaffected by the hydration state of the animal. This procedure thus provides a very rapid, but sensitive, set of techniques for studying the control of small peptide biosynthesis in the brain.

  7. The influence of temperatures and strain rates on the mechanical behavior of dual phase steel in different conditions

    Directory of Open Access Journals (Sweden)

    Yu Cao

    2015-01-01

    Full Text Available This study deals with the mechanical behavior of DP steel. A commercial dual phase steel (DP 800 was strained to 3.5% followed by annealing at 180 °C for 30 min to simulate the pressing of the plates and the paint-bake cycle involved in the manufacturing process of automobile body structures. The effect of temperature and strain rate on the mechanical behavior of this material was investigated by uniaxial tensile tests, covering applicable temperatures (−60 °C to 100 °C and strain rates (1 × 10−4 to 1 × 102 s−1 experienced in automotive crash situations. Yield and ultimate tensile strength, ductility, temperature effects and strain rate sensitivity as well as strain hardening rate have been determined and discussed.

  8. Halogen-free vapor phase epitaxy for high-rate growth of GaN bulk crystals

    Science.gov (United States)

    Nakamura, Daisuke; Kimura, Taishi; Horibuchi, Kayo

    2017-04-01

    Here, we propose a halogen-free vapor phase epitaxy (HF-VPE) technique to grow bulk GaN single crystals. This technique employs the simplest reaction for GaN synthesis (reaction of Ga vapor with NH3) and can potentially achieve a high growth rate, a prolonged growth duration, a high crystal quality, and a low cost. The analyses of thick HF-VPE-GaN layers grown under optimized growth conditions revealed that high-quality crystals, both in terms of dislocation density and impurity concentration, are obtained at high growth rates of over 100 µm/h.

  9. Molecular dynamics study on the effect of boundary heating rate on the phase change characteristics of thin film liquid

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Mohammad Nasim, E-mail: nasim@me.buet.ac.bd.com; Morshed, A. K. M. Monjur, E-mail: shavik@me.buet.ac.bd.com; Rabbi, Kazi Fazle, E-mail: rabbi35.me10@gmail.com; Haque, Mominul, E-mail: mominulmarup@gmail.com [Department of Mechanical Engineering, Bangladesh University of Engineering and Technology (BUET) Dhaka-1000 (Bangladesh)

    2016-07-12

    In this study, theoretical investigation of thin film liquid phase change phenomena under different boundary heating rates has been conducted with the help of molecular dynamics simulation. To do this, the case of argon boiling over a platinum surface has been considered. The study has been conducted to get a better understanding of the nano-scale physics of evaporation/boiling for a three phase system with particular emphasis on the effect of boundary heating rate. The simulation domain consisted of liquid and vapor argon atoms placed over a platinum wall. Initially the whole system was brought to an equilibrium state at 90 K with the help of equilibrium molecular dynamics and then the temperature of the bottom wall was increased to a higher temperature (250 K/130 K) over a finite heating period. Depending on the heating period, the boundary heating rate has been varied in the range of 1600×10{sup 9} K/s to 8×10{sup 9} K/s. The variations of argon region temperature, pressure, net evaporation number with respect to time under different boundary heating rates have been determined and discussed. The heat fluxes normal to platinum wall for different cases were also calculated and compared with theoretical upper limit of maximum possible heat transfer to elucidate the effect of boundary heating rate.

  10. Study on solid-liquid two-phase unsteady flow characteristics with different flow rates in screw centrifugal pump

    Science.gov (United States)

    Li, R. N.; Y Wang, H.; Han, W.; Ma, W.; Shen, Z. J.

    2013-12-01

    The screw centrifugal pump is used as an object, and the unsteady numerical simulation of solid-liquid two-phase flow is carried out under different flow rate conditions in one circle by choosing the two-phase flow of sand and water as medium, using the software FLUENT based on the URANS equations, combining with sliding mesh method, and choosing the Mixture multiphase flow model and the SIMPLE algorithm. The results show that, with the flow rate increasing, the change trends for the pressure on volute outlet are almost constant, the fluctuation trends of the impeller axial force have a little change, the pressure and the axial force turn to decrease on the whole, the radial force gradually increases when the impeller maximum radius passes by half a cycle near the volute outlet, and the radial force gradually decreases when the maximum radius passes by the other half a cycle in a rotation cycle. The distributions of the solid particles are very uneven under a small flow rate condition on the face. The solid particles under a big flow rate condition are distributed more evenly than the ones under a small flow rate condition on the back. The theoretical basis and reference are provided for improving its working performance.

  11. Rapid and high-throughput determination of endogenous cytokinins in Oryza sativa by bare Fe3O4 nanoparticles-based magnetic solid-phase extraction.

    Science.gov (United States)

    Cai, Bao-Dong; Zhu, Jiu-Xia; Gao, Qiang; Luo, Dan; Yuan, Bi-Feng; Feng, Yu-Qi

    2014-05-02

    A rapid method was developed for determination of endogenous cytokinins (CKs) based on magnetic solid-phase extraction (MSPE) followed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We illustrated the hydrophilic character of bare Fe3O4 nanoparticles that were directly used as a MSPE sorbent for rapid enrichment of endogenous CKs from complex plant extract. To the best of our knowledge, this is the first report of bare Fe3O4 directly used as efficient extraction sorbent to enrich target CKs based on hydrophilic interaction. Under the optimized conditions, a rapid, sensitive and high-throughput method for the determination of 16 CKs was established by combination of MSPE with UPLC-MS/MS. Good linearity was obtained with correlation coefficients (r) from 0.9902 to 0.9998. The limits of detection (LODs) and quantification (LOQs) ranged from 1.2 pg mL(-1) to 391.3 pg mL(-1) and 4.1 pg mL(-1) to 1304.3 pg mL(-1), respectively. 16 CKs could be successfully determined in spiked sample with 80.6-117.3% recoveries and the relative standard deviations (RSDs) were less than 16.6%. Finally, 10 endogenous CKs were successfully quantified in 50mg Oryza sativa sample using the developed MSPE-UPLC-MS/MS method. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. The evaluation of a rapid in situ HIV confirmation test in a programme with a high failure rate of the WHO HIV two-test diagnostic algorithm.

    Science.gov (United States)

    Klarkowski, Derryck B; Wazome, Joseph M; Lokuge, Kamalini M; Shanks, Leslie; Mills, Clair F; O'Brien, Daniel P

    2009-01-01

    Concerns about false-positive HIV results led to a review of testing procedures used in a Médecins Sans Frontières (MSF) HIV programme in Bukavu, eastern Democratic Republic of Congo. In addition to the WHO HIV rapid diagnostic test algorithm (RDT) (two positive RDTs alone for HIV diagnosis) used in voluntary counselling and testing (VCT) sites we evaluated in situ a practical field-based confirmation test against western blot WB. In addition, we aimed to determine the false-positive rate of the WHO two-test algorithm compared with our adapted protocol including confirmation testing, and whether weakly reactive compared with strongly reactive rapid test results were more likely to be false positives. 2864 clients presenting to MSF VCT centres in Bukavu during January to May 2006 were tested using Determine HIV-1/2 and UniGold HIV rapid tests in parallel by nurse counsellors. Plasma samples on 229 clients confirmed as double RDT positive by laboratory retesting were further tested using both WB and the Orgenics Immunocomb Combfirm HIV confirmation test (OIC-HIV). Of these, 24 samples were negative or indeterminate by WB representing a false-positive rate of the WHO two-test algorithm of 10.5% (95%CI 6.6-15.2). 17 of the 229 samples were weakly positive on rapid testing and all were negative or indeterminate by WB. The false-positive rate fell to 3.3% (95%CI 1.3-6.7) when only strong-positive rapid test results were considered. Agreement between OIC-HIV and WB was 99.1% (95%CI 96.9-99.9%) with no false OIC-HIV positives if stringent criteria for positive OIC-HIV diagnoses were used. The WHO HIV two-test diagnostic algorithm produced an unacceptably high level of false-positive diagnoses in our setting, especially if results were weakly positive. The most probable causes of the false-positive results were serological cross-reactivity or non-specific immune reactivity. Our findings show that the OIC-HIV confirmation test is practical and effective in field contexts

  13. The evaluation of a rapid in situ HIV confirmation test in a programme with a high failure rate of the WHO HIV two-test diagnostic algorithm.

    Directory of Open Access Journals (Sweden)

    Derryck B Klarkowski

    Full Text Available BACKGROUND: Concerns about false-positive HIV results led to a review of testing procedures used in a Médecins Sans Frontières (MSF HIV programme in Bukavu, eastern Democratic Republic of Congo. In addition to the WHO HIV rapid diagnostic test algorithm (RDT (two positive RDTs alone for HIV diagnosis used in voluntary counselling and testing (VCT sites we evaluated in situ a practical field-based confirmation test against western blot WB. In addition, we aimed to determine the false-positive rate of the WHO two-test algorithm compared with our adapted protocol including confirmation testing, and whether weakly reactive compared with strongly reactive rapid test results were more likely to be false positives. METHODOLOGY/PRINCIPAL FINDINGS: 2864 clients presenting to MSF VCT centres in Bukavu during January to May 2006 were tested using Determine HIV-1/2 and UniGold HIV rapid tests in parallel by nurse counsellors. Plasma samples on 229 clients confirmed as double RDT positive by laboratory retesting were further tested using both WB and the Orgenics Immunocomb Combfirm HIV confirmation test (OIC-HIV. Of these, 24 samples were negative or indeterminate by WB representing a false-positive rate of the WHO two-test algorithm of 10.5% (95%CI 6.6-15.2. 17 of the 229 samples were weakly positive on rapid testing and all were negative or indeterminate by WB. The false-positive rate fell to 3.3% (95%CI 1.3-6.7 when only strong-positive rapid test results were considered. Agreement between OIC-HIV and WB was 99.1% (95%CI 96.9-99.9% with no false OIC-HIV positives if stringent criteria for positive OIC-HIV diagnoses were used. CONCLUSIONS: The WHO HIV two-test diagnostic algorithm produced an unacceptably high level of false-positive diagnoses in our setting, especially if results were weakly positive. The most probable causes of the false-positive results were serological cross-reactivity or non-specific immune reactivity. Our findings show that the OIC

  14. Single- and Two-Phase Turbulent Mixing Rate between Subchannels in Triangle Tight Lattice Rod Bundle

    National Research Council Canada - National Science Library

    KAWAHARA, Akimaro; SADATOMI, Michio; KUDO, Hiroyuki; KANO, Keiko

    2006-01-01

    In order to obtain the data on turbulent mixing rate between triangle tight lattice subchannels, which will be adopted as the next generation BWR fuel rod bundle, adiabatic experiments were conducted...

  15. Impact of growth mode, phase, and rate on the metabolic state of the extremely thermophilic archaeon Pyrococcus furiosus.

    Science.gov (United States)

    Khatibi, Piyum A; Chou, Chung-Jung; Loder, Andrew J; Zurawski, Jeffrey V; Adams, Michael W W; Kelly, Robert M

    2017-12-01

    The archaeon Pyrococcus furiosus is emerging as a metabolic engineering platform for production of fuels and chemicals, such that more must be known about this organism's characteristics in bioprocessing contexts. Its ability to grow at temperatures from 70 to greater than 100°C and thereby avoid contamination, offers the opportunity for long duration, continuous bioprocesses as an alternative to batch systems. Toward that end, we analyzed the transcriptome of P. furiosus to reveal its metabolic state during different growth modes that are relevant to bioprocessing. As cells progressed from exponential to stationary phase in batch cultures, genes involved in biosynthetic pathways important to replacing diminishing supplies of key nutrients and genes responsible for the onset of stress responses were up-regulated. In contrast, during continuous culture, the progression to higher dilution rates down-regulated many biosynthetic processes as nutrient supplies were increased. Most interesting was the contrast between batch exponential phase and continuous culture at comparable growth rates (∼0.4 hr-1 ), where over 200 genes were differentially transcribed, indicating among other things, N-limitation in the chemostat and the onset of oxidative stress. The results here suggest that cellular processes involved in carbon and electron flux in P. furiosus were significantly impacted by growth mode, phase and rate, factors that need to be taken into account when developing successful metabolic engineering strategies. © 2017 Wiley Periodicals, Inc.

  16. Recruitment of faster motor units is associated with greater rates of fascicle strain and rapid changes in muscle force during locomotion.

    Science.gov (United States)

    Lee, Sabrina S M; de Boef Miara, Maria; Arnold, Allison S; Biewener, Andrew A; Wakeling, James M

    2013-01-15

    Animals modulate the power output needed for different locomotor tasks by changing muscle forces and fascicle strain rates. To generate the necessary forces, appropriate motor units must be recruited. Faster motor units have faster activation-deactivation rates than slower motor units, and they contract at higher strain rates; therefore, recruitment of faster motor units may be advantageous for tasks that involve rapid movements or high rates of work. This study identified motor unit recruitment patterns in the gastrocnemii muscles of goats and examined whether faster motor units are recruited when locomotor speed is increased. The study also examined whether locomotor tasks that elicit faster (or slower) motor units are associated with increased (or decreased) in vivo tendon forces, force rise and relaxation rates, fascicle strains and/or strain rates. Electromyography (EMG), sonomicrometry and muscle-tendon force data were collected from the lateral and medial gastrocnemius muscles of goats during level walking, trotting and galloping and during inclined walking and trotting. EMG signals were analyzed using wavelet and principal component analyses to quantify changes in the EMG frequency spectra across the different locomotor conditions. Fascicle strain and strain rate were calculated from the sonomicrometric data, and force rise and relaxation rates were determined from the tendon force data. The results of this study showed that faster motor units were recruited as goats increased their locomotor speeds from level walking to galloping. Slow inclined walking elicited EMG intensities similar to those of fast level galloping but different EMG frequency spectra, indicating that recruitment of the different motor unit types depended, in part, on characteristics of the task. For the locomotor tasks and muscles analyzed here, recruitment patterns were generally associated with in vivo fascicle strain rates, EMG intensity and tendon force. Together, these data provide

  17. Influences of rapid thermal process on solution-deposited Ti-silicate/Si films: Phase segregation, composition and interface changes, and dielectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Muk; Hwang, Soo Min [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Hwang, Soon Yong [Nano-Optical Property Laboratory and Department of Physics, Kyung Hee University, Seoul (Korea, Republic of); Kim, Tae Woong; Lee, Sang Hyub; Park, Geun Chul; Choi, Ju Yun [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Yoon, Jae Jin [KLA-Tencor Corporation, 1 Technology Drive, Milpitas, CA 95035 (United States); Kim, Tae Jung; Kim, Young Dong [Nano-Optical Property Laboratory and Department of Physics, Kyung Hee University, Seoul (Korea, Republic of); Kim, Hyoungsub [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Lim, Jun Hyung, E-mail: lanosjh@gmail.com [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Joo, Jinho, E-mail: jinho@skku.edu [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-05-01

    Ti-silicate/Si films were synthesized using a solution deposition route, and the effects of a rapid thermal process (RTP) on the microstructure, chemical bonding state, and interfacial layer (IL) properties were investigated and correlated to the permittivity of the films. The precursor solution was prepared from Ti(IV)-isopropoxide and tetraethylorthosilicate, spin-coated on HF-treated Si substrates, dried, pyrolyzed (400 °C), and subjected to the RTP at 700 °C–1000 °C. The Ti-silicate film consisted of Ti-rich and Si-rich silicates after the pyrolysis and phase segregation became significant as the RTP temperature increase. The silicates segregated into TiO{sub 2}-like nanocrystals and Si-richer silicate at up to 850 °C, and the TiO{sub 2}-like nanocrystals grew remarkably while the Si-richer silicate was converted into nearly pure SiO{sub 2} at 1000 °C. In addition, the Ti content in the Ti-silicate layer decreased due to Ti out-diffusion to the IL and substrate. Based on HRTEM, FT-IR, XPS, and SIMS analyses, we suggest a model of phase segregation with Ti diffusion and demonstrate that the Ti diffusion can be a critical issue in applications of Ti-silicate/Si systems, in addition to other well-known phenomena, including phase segregation, TiO{sub 2} precipitation, or interface properties. - Highlights: • Role of RTP on microstructure and properties of Ti-silicate film was investigated. • Phase segregation and Ti diffusion varied with the RTP. • Effects of the Ti diffusion on the dielectric properties were firstly investigated. • The Ti diffusion seemed to be one of the critical issues in the film applications. • New phase segregation model with Ti diffusion was suggested.

  18. A system for rapid large-area monitoring of gamma dose rates in the environment based on MCP-N (LiF:Mg,Cu,P) TL detectors.

    Science.gov (United States)

    Budzanowski, M; Olko, P; Ryba, E; Woźnicka, U

    2002-01-01

    One lesson learned from the Chernobyl accident was that the spatial distribution of far-field contamination was strongly non-uniform due to local variation of atmospheric conditions, such as wind direction, rain etc. An environmental monitoring system using highly sensitive thermoluminescent LiF:Mg,Cu,P (MCP-N) detectors has been completed and field-tested. The system consists of 3000 MCP-N detectors in 1000 TLD cards (three TLDs per card), two Mikrolab automatic TL readers, heating ovens, and specially developed software which includes a database for rapid evaluation of results. The main dosimetric parameters of MCP-N dosemeters, such as thermally-induced fading, light sensitivity, minimum detectable dose, self-dose, zero-dose, energy response up to 6-7 MeV, influence of annealing and readout conditions on detector stability, have been tested. About 100 locations over an area of about 15,000 km2 in the south of Poland were selected for measurements lasting from 4 days to 3 months. The kerma rates measured over a 4 day screening period agree well with kerma rates determined over a 75 day monitoring period. Results from short- and long-term exposure periods agree well with those performed using MTS-N (LiF:Mg,Ti) over southern Poland in 1985, before the Chernobyl accident. Thus, using the system based on MCP-N detectors, one is able simultaneously to monitor environmental radiation kerma rates at a large number of locations over periods of four days or less. Provided natural background kerma rates at selected monitoring points are available prior to the accident, the system can be applied to assess kerma rates rapidly in the environment, following a nuclear accident.

  19. 3,5-Diiodo-L-thyronine administration to hypothyroid rats rapidly enhances fatty acid oxidation rate and bioenergetic parameters in liver cells.

    Directory of Open Access Journals (Sweden)

    Alessandro Cavallo

    Full Text Available Growing evidence shows that, among triiodothyronine derivatives, 3,5 diiodo-L-thyronine (T(2 plays an important role in energy metabolism and fat storage. In the present study, short-term effects of T(2 administration to hypothyroid rats on fatty acid oxidation rate and bioenergetic parameters were investigated. Within 1 h following T(2 injection, state 3 and state 4 respiration rates, which were reduced in hypothyroid mitochondria, were noticeably increased particularly in succinate- with respect to glutamate/malate-energized mitochondria. Maximal respiratory activity, observed when glutamate/malate/succinate were simultaneously present in the respiratory medium, was significantly stimulated by T(2 treatment. A T(2-induced increase in respiratory rates was also observed when palmitoyl-CoA or L-palmitoylcarnitine were used as substrates. No significant change in respiratory control index and ADP/O ratio was observed. The activities of the mitochondrial respiratory chain complexes, especially Complex II, were increased in T(2-treated rats. In the latter, Complex V activities, assayed in both ATP synthesis and hydrolysis direction, were enhanced. The rate of fatty acid oxidation, followed by conversion of [(14C]palmitate to CO(2 and ketone bodies, was higher in hepatocytes isolated from T(2-treated rats. This increase occurs in parallel with the raise in the activity of carnitine palmitoyltransferase-I, the rate limiting enzyme of fatty acid β-oxidation, assayed in situ in digitonin-permeabilized hepatocytes. Overall, these results indicate that T(2 rapidly increases the ability of mitochondria to import and oxidize fatty acids. An emerging idea in the literature is the ability of T(2 to reduce adiposity and dyslipidemia and to prevent the development in liver steatosis. The results of the present study, showing a rapid T(2-induced increase in the ability of mitochondria to import and oxidize fatty acids, may contribute to understand the

  20. Rapid Generation of Multiplexed Cell Cocultures Using Acoustic Droplet Ejection Followed by Aqueous Two-Phase Exclusion Patterning

    Science.gov (United States)

    Fang, Yu; Frampton, John P.; Raghavan, Shreya; Sabahi-Kaviani, Rahman; Luker, Gary

    2012-01-01

    The development of tools for patterning cocultures of cells is a fundamental interest among cell biologists and tissue engineers. Although a variety of systems exist for micropatterning cells, the methods used to generate cell micropatterns are often cumbersome and difficult to adapt for tissue engineering purposes. This study combines acoustic droplet ejection and aqueous two-phase system exclusion patterning to introduce a method for patterning cocultures of cells in multiplexed arrays. This new method uses focused acoustic radiation pressure to eject discrete droplets of uniform size from the surface of a dextran solution containing cells. The size of droplets is controlled by adjusting ultrasound parameters, such as pulse, duration, and amplitude. The ejected dextran droplets are captured on a cell culture substrate that is manipulated by a computer-controlled 3D positioning system according to predesigned patterns. Polyethylene glycol solution containing an additional cell type is then added to the culture dish to produce a two-phase system capable of depositing different types of cells around the initial pattern of cells. We demonstrate that our method can produce patterns of islands or lines with two or more cell types. Further, we demonstrate that patterns can be multiplexed for studies involving combinations of multiple cell types. This method offers a tool to transfer cell-containing samples in a contact-free, nozzle-less manner, avoiding sample cross-contamination. It can be used to pattern cell cocultures without complicated fabrication of culture substrates. These capabilities were used to examine the response of cancer cells to the presence of a ligand (CXCL12) secreted from surrounding cocultured cells. PMID:22356298

  1. Magnetic solid phase extraction coupled with desorption corona beam ionization-mass spectrometry for rapid analysis of antidepressants in human body fluids.

    Science.gov (United States)

    Chen, Di; Zheng, Hao-Bo; Huang, Yun-Qing; Hu, Yu-Ning; Yu, Qiong-Wei; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-08-21

    Ambient ionization techniques show good potential in rapid analysis of target compounds. However, a direct application of these ambient ionization techniques for the determination of analytes in a complex matrix is difficult due to the matrix interference and ion suppression. To resolve this problem, here we developed a strategy by coupling magnetic solid phase extraction (MSPE) with desorption corona beam ionization (DCBI)-mass spectrometry (MS). As a proof of concept, the pyrrole-coated Fe3O4 magnetic nanoparticles (Fe3O4@Ppy) were prepared and used for the extraction of antidepressants. After extraction, the Fe3O4@Ppy with trapped antidepressants was then directly subjected to DCBI-MS analysis with the aid of a homemade magnetic glass capillary. As the MSPE process is rapid and the direct DCBI-MS analysis does not need solvent desorption or chromatographic separation processes, the overall analysis can be completed within 3 min. The proposed MSPE-DCBI-MS method was then successfully used to determine antidepressants in human urine and plasma. The calibration curves were obtained in the range of 0.005-0.5 μg mL(-1) for urine and 0.02-1 μg mL(-1) for plasma with reasonable linearity (R(2) > 0.951). The limits of detection of three antidepressants were in the range of 0.2-1 ng mL(-1) for urine and 2-5 ng mL(-1) for plasma. Acceptable reproducibility for rapid analysis was achieved with relative standard deviations less than 19.1% and the relative recoveries were 85.2-118.7%. Taken together, the developed MSPE-DCBI-MS strategy offers a powerful capacity for rapid analysis of target compounds in a complex matrix, which would greatly expand the applications of ambient ionization techniques with plentiful magnetic sorbents.

  2. Quantification of whey proteins by reversed phase-HPLC and effectiveness of mid-infrared spectroscopy for their rapid prediction in sweet whey.

    Science.gov (United States)

    Sturaro, Alba; De Marchi, Massimo; Masi, Antonio; Cassandro, Martino

    2016-01-01

    In the dairy industry, membrane filtration is used to reduce the amount of whey waste and, simultaneously, to recover whey proteins (WP). The composition of WP can strongly affect the filtration treatment of whey, and rapid determination of WP fractions would be of interest for dairy producers to monitor WP recovery. This study aimed to develop mid-infrared spectroscopy (MIRS) prediction models for the rapid quantification of protein in sweet whey, using a validated rapid reversed phase (RP)-HPLC as a reference method. Quantified WP included α-lactalbumin (α-LA), β-lactoglobulin (β-LG) A and B, bovine serum albumin, caseinomacropeptides, and proteose peptone. Validation of RP-HPLC was performed by calculating the relative standard deviation (RSD) in repeatability and reproducibility tests for WP retention time and peak areas. Samples of liquid whey (n=187) were analyzed by RP-HPLC and scanned through MIRS to collect spectral information (900 to 4,000 cm(-1)); statistical analysis was carried out through partial least squares regression and random cross-validation procedure. Retention times in RP-HPLC method were stable (RSD between 0.03 and 0.80%), whereas the RSD of peak area (from 0.25 to 8.48%) was affected by WP relative abundance. Higher coefficients of determination in validation for MIRS model were obtained for protein fractions present in whey in large amounts, such as β-LG (0.58), total identified WP (0.58), and α-LA (0.56). Results of this study suggest that MIRS is an easy method for rapid quantification of detail protein in sweet whey, even if better resolution was achieved with the method based on RP-HPLC. The prediction of WP in sweet whey by MIRS might be used for screening and for classifying sweet whey according to its total and individual WP contents. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Rapid determination of strontium-90 by solid phase extraction using DGA Resin® for seawater monitoring

    Science.gov (United States)

    Tazoe, H.; Obata, H.; Yamagata, T.; Karube, Z.; Yamada, M.

    2015-12-01

    Strontium-90 concentrations in seawater exceeding the background level have been observed at the accidents of nuclear facilities, such as Chernobyl and Fukushima. However, analytical procedure for strontium-90 in seawater is still quite complicated and challenging. Here we show a simple and rapid analytical technique for the determination of strontium-90 in seawater samples without time-consuming separation of strontium from calcium. The separation with DGA Resin® is used to determine the abundance of strontium-90, which selectively collects yttrium-90, progeny of strontium-90. Naturally occurring radioactive nuclides (such as potassium, lead, bismuth, uranium, and thorium) and anthropogenic radionuclides (such as cesium, barium, lanthanum, and cerium) were separated from yttrium. Through a sample separation procedure, a high chemical yield of yttrium-90 was achieved at 93.9 % for seawater. The result of IAEA 443 certified seawater analysis was in good agreement with the certified value. At 20 hrs counting a lower detection limit of 1.5 mBq L-1 was obtained from 3 L of seawater. The proposed method can finish analyzing 8 samples per day, which is a reasonably fast throughput in actual seawater monitoring. Reproducibility was found to be 3.4 % according to 10 separate analyses of natural seawater samples from the vicinity of Fukushima Daiichi Nuclear Power Plant in September 2013.

  4. A New Process for Hot Metal Production at Low Fuel Rate - Phase 1 Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Wei-Kao Lu

    2006-02-01

    The project is part of the continuing effort by the North American steel industry to develop a coal-based, cokeless process for hot metal production. The objective of Phase 1 is to determine the feasibility of designing and constructing a pilot scale facility with the capacity of 42,000 mtpy of direct reduced iron (DRI) with 95% metallization. The primary effort is performed by Bricmont, Inc., an international engineering firm, under the supervision of McMaster University. The study focused on the Paired Straight Hearth furnace concept developed previously by McMaster University, The American Iron and Steel Institute and the US Department of Energy.

  5. Nine-year change in statistical design, profile, and success rates of Phase II oncology trials.

    Science.gov (United States)

    Ivanova, Anastasia; Paul, Barry; Marchenko, Olga; Song, Guochen; Patel, Neerali; Moschos, Stergios J

    2016-01-01

    We investigated nine-year trends in statistical design and other features of Phase II oncology clinical trials published in 2005, 2010, and 2014 in five leading oncology journals: Cancer, Clinical Cancer Research, Journal of Clinical Oncology, Annals of Oncology, and Lancet Oncology. The features analyzed included cancer type, multicenter vs. single-institution, statistical design, primary endpoint, number of treatment arms, number of patients per treatment arm, whether or not statistical methods were well described, whether the drug was found effective based on rigorous statistical testing of the null hypothesis, and whether the drug was recommended for future studies.

  6. Gas-Phase Photolysis of Pyruvic Acid: The Effect of Pressure on Reaction Rates and Products.

    Science.gov (United States)

    Reed Harris, Allison E; Doussin, Jean-Francois; Carpenter, Barry K; Vaida, Veronica

    2016-12-29

    In this work, we investigate the impact of pressure and oxygen on the kinetics of and products from the gas-phase photolysis of pyruvic acid. The results reveal a decrease in the photolysis quantum yield as pressure of air or nitrogen is increased, a trend not yet documented in the literature. A Stern-Volmer analysis demonstrates this effect is due to deactivation of the singlet state of pyruvic acid when the photolysis is performed in nitrogen, and from quenching of both the singlet and triplet state in air. Consistent with previous studies, acetaldehyde and CO 2 are observed as the major products; however, other products, most notably acetic acid, are also identified in this work. The yield of acetic acid increases with increasing pressure of buffer gas, an effect that is amplified by the presence of oxygen. At least two mechanisms are necessary to explain the acetic acid, including one that requires reaction of photolysis intermediates with O 2 . These findings extend the fundamental understanding of the gas-phase photochemistry of pyruvic acid, highlighting the importance of pressure on the photolysis quantum yields and products.

  7. Rapid determination of 54 pharmaceutical and personal care products in fish samples using microwave-assisted extraction-Hollow fiber-Liquid/solid phase microextraction.

    Science.gov (United States)

    Zhang, Yi; Guo, Wen; Yue, Zhenfeng; Lin, Li; Zhao, Fengjuan; Chen, Peijin; Wu, Weidong; Zhu, Hong; Yang, Bo; Kuang, Yanyun; Wang, Jiong

    2017-04-15

    In this paper, a simple, rapid, solvent-less and environmental friendliness microextraction method, microwave-assisted extraction-hollow fiber-liquid/solid phase microextraction (MAE-HF-L/SME), was developed for simultaneous extraction and enrichment of 54 trace hydrophilic/lipophilic pharmaceutical and personal care products (PPCPs) from fish samples. A solid-phase extraction material, solid-phase microextraction (SPME) fiber, was synthesized. The SPME fiber had a homogeneous, loose structure and good mechanical properties, and they exhibited a good adsorption capacity for most PPCPs selected. The material formed the basis for the method of MAE-HF-L/SME. A method of liquid chromatography-high resolution mass spectroscopy (LC-HRMS) for analysis of 54 PPCPs. Under optimal synthesis and extraction conditions, the limits of detection (LODs, n=3) and the limits of quantitation (LOQs, n=10) for the 54 PPCPs were between 0.01-0.50μg·kg-1 and 0.052.00μg·kg-1, respectively. Percent recoveries and the relative standard deviations (RSDs) in spiked fish samples (n=6) were between 56.3%-119.9% and 0.3%-17.1%, respectively. The microextraction process of 54 PPCPs in MAE-HF-L/SME took approximately 12min. The method has a low matrix interference and high enrichment factor and may be applicable for determination of 54 different PPCPs in fish samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Rapid, bilateral changes in growth rate and curvature during gravitropism of cucumber hypocotyls: implications for mechanism of growth control

    Science.gov (United States)

    Cosgrove, D. J.

    1990-01-01

    The growth response of etiolated cucumber (Cucumis sativus L.) hypocotyls to gravitropic stimulation was examined by means of time-lapse photography and high-resolution analysis of surface expansion and curvature. In comparison with video analysis, the technique described here has five- to 20-fold better resolution; moreover, the mathematical fitting method (cubic splines) allows direct estimation of local and integrated curvature. After switching seedlings from a vertical to horizontal position, both upper and lower surfaces of the stem reacted after a lag of about 11 min with a two- to three-fold increase in surface expansion rate on the lower side and a cessation of expansion, or slight compression, on the upper surface. This growth asymmetry was initiated simultaneously along the length of the hypocotyl, on both upper and lower surfaces, and did not migrate basipetally from the apex. Later stages in the gravitropic response involved a complex reversal of the growth asymmetry, with the net result being a basipetal migration of the curved region. This secondary growth reversal may reflect oscillatory and/or self-regulatory behaviour of growing cells. With some qualifications, the kinetics and pattern of growth response are consistent with a mechanism involving hormone redistribution, although they do not prove such a mechanism. The growth kinetics require a growth mechanism which can be stimulated by two- to three-fold or completely inhibited within a few minutes.

  9. Live, video-rate super-resolution microscopy using structured illumination and rapid GPU-based parallel processing.

    Science.gov (United States)

    Lefman, Jonathan; Scott, Keana; Stranick, Stephan

    2011-04-01

    Structured illumination fluorescence microscopy is a powerful super-resolution method that is capable of achieving a resolution below 100 nm. Each super-resolution image is computationally constructed from a set of differentially illuminated images. However, real-time application of structured illumination microscopy (SIM) has generally been limited due to the computational overhead needed to generate super-resolution images. Here, we have developed a real-time SIM system that incorporates graphic processing unit (GPU) based in-line parallel processing of raw/differentially illuminated images. By using GPU processing, the system has achieved a 90-fold increase in processing speed compared to performing equivalent operations on a multiprocessor computer--the total throughput of the system is limited by data acquisition speed, but not by image processing. Overall, more than 350 raw images (16-bit depth, 512 × 512 pixels) can be processed per second, resulting in a maximum frame rate of 39 super-resolution images per second. This ultrafast processing capability is used to provide immediate feedback of super-resolution images for real-time display. These developments are increasing the potential for sophisticated super-resolution imaging applications.

  10. Automatic Stand Modeling of Casting Rate Influence on Solid Phase Growth of Round Ingot inside Crystallizer

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available The method of calculation and results of computer dynamics modeling of solid ingot skin in a crystallizer are presented in the paper. The paper shows influence of ingot drawing rate on dynamics of solid ingot skin growth in the continuous casting machine at steel grades used at Republic Unitary Enterprise «Belarussian Metallurgical Works» (BMZ.

  11. Rapid diagnosis and treatment of TIA results in low rates of stroke, myocardial infarction and vascular death.

    Science.gov (United States)

    Cocho, D; Monell, J; Planells, G; Ricciardi, A C; Pons, J; Boltes, A; Espinosa, J; Ayats, M; Garcia, N; Otermin, P

    2016-01-01

    The 90-day risk of cerebral infarction in patients with transient ischaemic attack (TIA) is estimated at between 8% and 20%. There is little consensus as to which diagnostic strategy is most effective. This study evaluates the benefits of early transthoracic echocardiography (TTE) with carotid and transcranial Doppler ultrasound in patients with TIA. Prospective study of patients with TIA in an emergency department setting. Demographic data, vascular risk factors, and ABCD(2) score were analysed. TIA aetiology was classified according to TOAST criteria. All patients underwent early vascular studies (<72hours), including TTE, carotid ultrasound, and transcranial Doppler. Primary endpoints were recurrence of stroke or TIA, myocardial infarction (MI), or vascular death during the first year. We evaluated 92 patients enrolled over 24 months. Mean age was 68.3±13 years and 61% were male. The mean ABCD(2) score was 3 points (≥5 in 30%). The distribution of TIA subtypes was as follows: 12% large-artery atherosclerosis; 30% cardioembolism; 10% small-vessel occlusion; 40% undetermined cause; and 8% rare causes. Findings from the early TTE led to a change in treatment strategy in 6 patients (6.5%) who displayed normal physical examination and ECG findings. At one year of follow-up, 3 patients had experienced stroke (3.2%) and 1 patient experienced MI (1%); no vascular deaths were identified. In our TIA patients, early vascular study and detecting patients with silent cardiomyopathy may have contributed to the low rate of vascular disease recurrence. Copyright © 2014 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  12. Automated method for the rapid and precise estimation of adherent cell culture characteristics from phase contrast microscopy images.

    Science.gov (United States)

    Jaccard, Nicolas; Griffin, Lewis D; Keser, Ana; Macown, Rhys J; Super, Alexandre; Veraitch, Farlan S; Szita, Nicolas

    2014-03-01

    The quantitative determination of key adherent cell culture characteristics such as confluency, morphology, and cell density is necessary for the evaluation of experimental outcomes and to provide a suitable basis for the establishment of robust cell culture protocols. Automated processing of images acquired using phase contrast microscopy (PCM), an imaging modality widely used for the visual inspection of adherent cell cultures, could enable the non-invasive determination of these characteristics. We present an image-processing approach that accurately detects cellular objects in PCM images through a combination of local contrast thresholding and post hoc correction of halo artifacts. The method was thoroughly validated using a variety of cell lines, microscope models and imaging conditions, demonstrating consistently high segmentation performance in all cases and very short processing times (microscopy image processing pipelines. Furthermore, PCM image segmentation was used to facilitate the interpretation and analysis of fluorescence microscopy data, enabling the determination of temporal and spatial expression patterns of a fluorescent reporter. We created a software toolbox (PHANTAST) that bundles all the algorithms and provides an easy to use graphical user interface. Source-code for MATLAB and ImageJ is freely available under a permissive open-source license. © 2013 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

  13. Rapid analysis of polybrominated diphenyl ethers in soil by matrix solid-phase dispersion using bamboo charcoal as dispersive sorbent.

    Science.gov (United States)

    Yuan, Jin-Peng; Zhao, Ru-Song; Cheng, Chuan-Ge; Wang, Xiao-Li; Cui, Zhao-Jie

    2012-09-01

    An expeditious and sensitive method for the analysis of eight major polybrominated diphenyl ethers (PBDEs) in soil is presented in this study. The method is based on matrix solid-phase dispersion (MSPD) extraction and gas chromatography with negative chemical ionization mass spectrometry. Bamboo charcoal, a cheap and potentially useful material, was selected for the first time as the MSPD dispersive sorbent. Parameters affecting the extraction efficiency, including the ratio of sorbent to sample, and the type and amount of eluent, were investigated and optimized in detail. Under optimal conditions, the spiked recovery of the PBDEs was in the range 71.7-105.9%, and the limits of detection varied from 10 to 400 pg g(-1) (dry weight). Excellent linearity with correlation coefficients (r(2)) of 0.9992-0.9999 was obtained over the concentration range of 0.10-500 ng g(-1) , except for BDE-209, for which the effective concentration range was 1.0-5000 ng g(-1) . The developed method has been successfully applied to the analysis of PBDEs in real soil samples. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Quantifying factors determining the rate of CTL escape and reversion during acute and chronic phases of HIV infection

    Energy Technology Data Exchange (ETDEWEB)

    Ganusov, Vitaly V [Los Alamos National Laboratory; Korber, Bette M [Los Alamos National Laboratory; Perelson, Alan S [Los Alamos National Laboratory

    2009-01-01

    Human immunodeficiency virus (HIV) often evades cytotoxic T cell (CTL) responses by generating variants that are not recognized by CTLs. However, the importance and quantitative details of CTL escape in humans are poorly understood. In part, this is because most studies looking at escape of HIV from CTL responses are cross-sectional and are limited to early or chronic phases of the infection. We use a novel technique of single genome amplification (SGA) to identify longitudinal changes in the transmitted/founder virus from the establishment of infection to the viral set point at 1 year after the infection. We find that HIV escapes from virus-specific CTL responses as early as 30-50 days since the infection, and the rates of viral escapes during acute phase of the infection are much higher than was estimated in previous studies. However, even though with time virus acquires additional escape mutations, these late mutations accumulate at a slower rate. A poor correlation between the rate of CTL escape in a particular epitope and the magnitude of the epitope-specific CTL response suggests that the lower rate of late escapes is unlikely due to a low efficacy of the HIV-specific CTL responses in the chronic phase of the infection. Instead, our results suggest that late and slow escapes are likely to arise because of high fitness cost to the viral replication associated with such CTL escapes. Targeting epitopes in which virus escapes slowly or does not escape at all by CTL responses may, therefore, be a promising direction for the development of T cell based HIV vaccines.

  15. High-data rate differential phase shift keying receiver for satellite-to-ground optical communication link

    Science.gov (United States)

    Zhi, Yan'an; Sun, Jianfeng; Dai, Enwen; Zhou, Yu; Wang, Lijuan; Lu, Wei; Hou, Peipei; Liu, Liren

    2012-10-01

    The high data-rate satellite-to-ground coherent optical communication link is limited because the phase integrity of a beam is impaired when passing through the atmospheric turbulence. Based on the interference of two successive data bits in an unequal arm-length Mach-Zehnder delay interferometer, the differential phase shift keying receiver is suited for high data-rate satellite-to-ground coherent optical communication links due to its immunity of the wave front impairment when passing through the atmospheric turbulence. In the time-delay self-homodyne interferometric detection used in 2×4 90 degree optical hybrid, the optical path difference corresponds to the duration of one bit. The optical path difference is stabilized to below one thousandth of the wavelength by moving a finely motorized platform with the close-loop control using the phase feedback from the outputs of the 90 degree hybrid. The 2.5 Gbps optical communication link has already been verified between two buildings over a distance of 2.4km in the worst-case atmospheric conditions. The design and experimental results are given in this paper.

  16. Stabilization and phase control of femtosecond Ti:sapphire laser with a repetition rate of 90MHz

    Science.gov (United States)

    Zhang, Wei; Han, Hainian; Wang, Peng; Wei, Zhiyi

    2007-01-01

    Carrier-enveloped phase controlled femtosecond laser has an important application in the absolute frequency measurement, which lead to a revolutionary progress in the frequency metrology. In this paper we will report a high stable optical frequency comb based on a 90MHz repetition rate Ti:sapphire laser, by using a photonic crystal fiber to broaden octave spanning spectrum and a self-reference technology to measure the offset frequency f ceo, both the repetition rate f rep and f ceo are locked simultaneously to a cesium clock with phase lock loop (PLL) technology. For simultaneous stabilization of f rep and f ceo, two sets of phase-locked loop electronics are introduced to control separately the laser cavity length for f rep with a PZT and the pump laser for f ceo with an acoustic optics modulation (AOM) respectively. As the result, we stabilized the f rep at a fluctuation within the order of μHz, and f ceo is in the order of mHz, which support a frequency comb with an uncertainty of 10 -14.

  17. Shutdown Dose Rate Analysis for the long-pulse D-D Operation Phase in KSTAR

    Directory of Open Access Journals (Sweden)

    Park Jin Hun

    2017-01-01

    Full Text Available KSTAR is a medium size fully superconducting tokamak. The deuterium-deuterium (D-D reaction in the KSTAR tokamak generates neutrons with a peak yield of 3.5x1016 per second through a pulse operation of 100 seconds. The effect of neutron generation from full D-D high power KSTAR operation mode to the machine, such as activation, shutdown dose rate, and nuclear heating, are estimated for an assurance of safety during operation, maintenance, and machine upgrade. The nuclear heating of the in-vessel components, and neutron activation of the surrounding materials have been investigated. The dose rates during operation and after shutdown of KSTAR have been calculated by a 3D CAD model of KSTAR with the Monte Carlo code MCNP5 (neutron flux and decay photon, the inventory code FISPACT (activation and decay photon and the FENDL 2.1 nuclear data library.

  18. Macroscopic rates, microscopic observations, and molecular models of the dissolution of carbonate phases.

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, Owen W. (Harvard University, Cambridge, MA); Cygan, Randall Timothy; Martin, Scot T. (Harvard University, Cambridge, MA)

    2004-05-01

    Bulk and surface energies are calculated for endmembers of the isostructural rhombohedral carbonate mineral family, including Ca, Cd, Co, Fe, Mg, Mn, Ni, and Zn compositions. The calculations for the bulk agree with the densities, bond distances, bond angles, and lattice enthalpies reported in the literature. The calculated energies also correlate with measured dissolution rates: the lattice energies show a log-linear relationship to the macroscopic dissolution rates at circumneutral pH. Moreover, the energies of ion pairs translated along surface steps are calculated and found to predict experimentally observed microscopic step retreat velocities. Finally, pit formation excess energies decrease with increasing pit size, which is consistent with the nonlinear dissolution kinetics hypothesized for the initial stages of pit formation.

  19. Rapid burst kinetics in the hydrolysis of 4-nitrophenyl acetate by penicillin G acylase from Kluyvera citrophila. Effects of mutation F360V on rate constants for acylation and de-acylation.

    Science.gov (United States)

    Roa, A; Goble, M L; García, J L; Acebal, C; Virden, R

    1996-06-01

    The kinetics of release of 4-nitrophenol were followed by stopped-flow spectrophotometry with two 4-nitrophenyl ester substrates of penicillin G acylase from Kluyvera citrophila. With the ester of acetic acid, but not of propionic acid, there was a pre-steady-state exponential phase, the kinetics of which were inhibited by phenylacetic acid (a product of hydrolysis of specific substrates) to the extent predicted from Ki values. This was interpreted as deriving from rapid formation (73 mM-1.s-1) and slow hydrolysis (0.76 s-1) of an acetyl derivative of the side chain of the catalytic-centre residue Ser-290. With the mutant F360V, which differs from the wild-type enzyme in its ability to hydrolyse adipyl-L-leucine and has a kcat for 4-nitrophenyl acetate one-twentieth that of the wild-type enzyme, the corresponding values for the rates of formation and hydrolysis of the acetyl-enzyme were 11.1 mM-1.s-1 and 0.051 s-1 respectively. The ratio of these rate constants was three times that for the wild-type enzyme, suggesting that the mutant is less impaired in the rate of formation of an acetyl-enzyme than in its subsequent hydrolysis.

  20. Repeated injections of D-Amphetamine evoke rapid and dynamic changesin phase synchrony between the prefrontal cortex and hippocampus

    Directory of Open Access Journals (Sweden)

    SUNGWOO eAHN

    2013-07-01

    Full Text Available Repeated drug use evokes a number of persistent alterations in oscillatory power and synchrony. How synchronous activity in cortico-hippocampal circuits is progressively modified with repeated drug exposure, however, remains to be characterized. Drugs of abuse induce both short-term and long-term adaptations in cortical and hippocampal circuits and these changes are likely important for the expression of the altered behavioral and neurobiological phenotype associated with addiction. The present study explores how the initial (up to one hour pharmacological response to D-Amphetamine (AMPH is altered with repeated injections in the rat. The methods employed herein allow for the progressive changes in synchronized dynamics with repeated intermittent AMPH exposure to be characterized over short time scales (minutes. Specifically, we examined the temporal variations of phase-locking strength in delta and theta bands within the prefrontal cortex (PFC and between PFC and hippocampus (HC shortly after drug injection. After the first injection of AMPH synchrony increased within the PFC in the delta band, which was followed, by an increase in theta synchrony between the PFC and HC several minutes later. This relationship switched after repeated AMPH injections, where increases in theta synchrony between the PFC and HC preceded increases in delta synchrony in the PFC. The time-course of increases in synchronous activity were negatively correlated between the PFC delta and the PFC-HC theta. Collectively these data highlight the potential role of PFC-HC circuits in the development of addiction and outline dynamic changes in the time-course that cortico-hippocampal circuits become synchronized with repeated AMPH exposure.

  1. Fischer-Tropsch synthesis in supercritical phase carbon dioxide: Recycle rates

    Science.gov (United States)

    Soti, Madhav

    With increasing oil prices and attention towards the reduction of anthropogenic CO2, the use of supercritical carbon dioxide for Fischer Tropsch Synthesis (FTS) is showing promise in fulfilling the demand of clean liquid fuels. The evidence of consumption of carbon dioxide means that it need not to be removed from the syngas feed to the Fischer Tropsch reactor after the gasification process. Over the last five years, research at SIUC have shown that FTS in supercritical CO2reduces the selectivities for methane, enhances conversion, reduces the net CO2produces in the coal to liquid fuels process and increase the life of the catalyst. The research has already evaluated the impact of various operating and feed conditions on the FTS for the once through process. We believe that the integration of unreacted feed recycle would enhance conversion, increase the yield and throughput of liquid fuels for the same reactor size. The proposed research aims at evaluating the impact of recycle of the unreacted feed gas along with associated product gases on the performance of supercritical CO2FTS. The previously identified conditions will be utilized and various recycle ratios will be evaluated in this research once the recycle pump and associated fittings have been integrated to the supercritical CO2FTS. In this research two different catalysts (Fe-Zn-K, Fe-Co-Zn-K) were analyzed under SC-FTS in different recycle rate at 350oC and 1200 psi. The use of recycle was found to improve conversion from 80% to close to 100% with both catalysts. The experiment recycle rate at 4.32 and 4.91 was clearly surpassing theoretical recycle curve. The steady state reaction rate constant was increased to 0.65 and 0.8 min-1 for recycle rate of 4.32 and 4.91 respectively. Carbon dioxide selectivity was decreased for both catalyst as it was converting to carbon monoxide. Carbon dioxide consumption was increased from 0.014 to 0.034 mole fraction. This concluded that CO2is being used in the system and

  2. Magnetic ionic liquid aqueous two-phase system coupled with high performance liquid chromatography: A rapid approach for determination of chloramphenicol in water environment.

    Science.gov (United States)

    Yao, Tian; Yao, Shun

    2017-01-20

    A novel organic magnetic ionic liquid based on guanidinium cation was synthesized and characterized. A new method of magnetic ionic liquid aqueous two-phase system (MILATPs) coupled with high-performance liquid chromatography (HPLC) was established to preconcentrate and determine trace amount of chloramphenicol (CAP) in water environment for the first time. In the absence of volatile organic solvents, MILATPs not only has the excellent properties of rapid extraction, but also exhibits a response to an external magnetic field which can be applied to assist phase separation. The phase behavior of MILATPs was investigated and phase equilibrium data were correlated by Merchuk equation. Various influencing factors on CAP recovery were systematically investigated and optimized. Under the optimal conditions, the preconcentration factor was 147.2 with the precision values (RSD%) of 2.42% and 4.45% for intra-day (n=6) and inter-day (n=6), respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.14ngmL(-1) and 0.42ngmL(-1), respectively. Fine linear range of 12.25ngmL(-1)-2200ngmL(-1) was obtained. Finally, the validated method was successfully applied for the analysis of CAP in some environmental waters with the recoveries for the spiked samples in the acceptable range of 94.6%-99.72%. Hopefully, MILATPs is showing great potential to promote new development in the field of extraction, separation and pretreatment of various biochemical samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Rapid determination of six carcinogenic primary aromatic amines in mainstream cigarette smoke by two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Bie, Zhenying; Lu, Wei; Zhu, You; Chen, Yusong; Ren, Hubo; Ji, Lishun

    2017-01-27

    A fully automated, rapid, and reliable method for simultaneous determination of six carcinogenic primary aromatic amines (AAs), including o-toluidine (o-TOL), 2, 6-dimethylaniline (2, 6-DMA), o-anisidine (o-ASD), 1-naphthylamine (1-ANP), 2-naphthylamine (2-ANP), and 4-aminobiphenyl (4-ABP), in mainstream cigarette smoke was established. The proposed method was based on two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry (SPE/LC-MS/MS). The particulate phase of the mainstream cigarette smoke was collected on a Cambridge filter pad and pretreated via ultrasonic extraction with 2% formic acid (FA), while the gas phase was trapped by 2% FA without pretreatment for determination. The two-dimensional online SPE comprised of two cartridges with different absorption characteristics was applied for sample pretreatment. Analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) under multiple reaction monitoring mode. Each sample required about 0.5h for solid phase extraction and analysis. The limit of detections (LODs) for six AAs ranged from 0.04 to 0.58ng/cig and recoveries were within 84.5%-122.9%. The relative standard deviations of intra- and inter-day tests for 3R4F reference cigarette were less than 6% and 7%, respectively, while no more than 7% and 8% separately for a type of Virginia cigarette. The proposed method enabled minimum sample pretreatment, full automation, and high throughput with high selectivity, sensitivity, and accuracy. As a part of the validation procedure, fifteen brands of cigarettes were tested by the designed method. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Rapid magnetic solid-phase extraction based on monodisperse magnetic single-crystal ferrite nanoparticles for the determination of free fatty acid content in edible oils.

    Science.gov (United States)

    Wei, Fang; Zhao, Qin; Lv, Xin; Dong, Xu-Yan; Feng, Yu-Qi; Chen, Hong

    2013-01-09

    This study proposes a rapid magnetic solid-phase extraction (MSPE) based on monodisperse magnetic single-crystal ferrite (Fe(3)O(4)) nanoparticles (NPs) for determining the quantities of eight free fatty acids (FFAs), including palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), arachidic acid (C20:0), eicosenoic acid (C20:1), and behenic acid (C22:0) in oil. The amine-functionalized mesoporous Fe(3)O(4) magnetic NPs were applied as a sorbent for MSPE of FFAs from oil samples in a process that is based on hydrophilic interaction. The extraction can be completed rapidly in a dispersive mode with the aid of vigorous vortex. Additional tedious processing steps such as centrifugation and evaporation of organic solvent were not necessary with this procedure. Furthermore, esterification of FFAs can be accomplished during the desorption procedure by using methanol/sulfuric acid (99:1, v/v) as the desorption solvent. Several parameters affecting the extraction efficiency were investigated, including the matrix solvent for extraction, the desorption solvent and desorption time, and the amount of sorbent and extraction time. The pretreatment process was rapid under optimal conditions, being accomplished within 15 min. When coupled with gas chromatography-flame ionization detection (GC-FID), a rapid, simple, and convenient MSPE-GC-FID method for the determination of FFAs in oil samples was established with a total analysis time within 25 min. The limits of detection for the target FFAs were found to be 7.22-26.26 ng/mL. Recoveries in oil samples were in the range of 81.33-117.75%, with RSDs of <6.4% (intraday) and <6.9% (interday). This method was applied successfully to the analysis of dynamic FFA formation in four types of edible oils subjected to an accelerated storage test. The simple, rapid, and cost-effective method developed in the current study offers a potential application for the extraction and

  5. Structure-activity relationship for the estimation of OH-oxidation rate constants of carbonyl compounds in the aqueous phase

    Science.gov (United States)

    Doussin, J.-F.; Monod, A.

    2013-12-01

    In the atmosphere, one important class of reactions occurs in the aqueous phase in which organic compounds are known to undergo oxidation towards a number of radicals, among which OH radicals are the most reactive oxidants. In 2008, Monod and Doussin have proposed a new structure-activity relationship (SAR) to calculate OH-oxidation rate constants in the aqueous phase. This estimation method is based on the group-additivity principle and was until now limited to alkanes, alcohols, acids, bases and related polyfunctional compounds. In this work, the initial SAR is extended to carbonyl compounds, including aldehydes, ketones, dicarbonyls, hydroxy carbonyls, acidic carbonyls, their conjugated bases, and the hydrated form of all these compounds. To do so, only five descriptors have been added and none of the previously attributed descriptors were modified. This extension leads now to a SAR which is based on a database of 102 distinct compounds for which 252 experimental kinetic rate constants have been gathered and reviewed. The efficiency of this updated SAR is such that 58% of the rate constants could be calculated within ±20% of the experimental data and 76% within ±40% (respectively 41 and 72% for the carbonyl compounds alone).

  6. Effects of rapid versus standard HIV voluntary counselling and testing on receipt rate of HIV test results: a meta-analysis.

    Science.gov (United States)

    Wang, Yuan; Guo, Jian; Lu, Wenli

    2015-03-01

    Rapid HIV voluntary counselling and testing (RVCT) is an alternative method of standard HIV voluntary counselling and testing (SVCT). Less is known about whether RVCT improves the receipt rate of HIV test results among clients who seek HIV counselling and testing. We aimed to evaluate effectiveness of RVCT on result receipt rate. We conducted a comprehensive search of databases containing Medline, EBSCO, Web of science, and Cochrane library to identify studies published up to August 2012. Reviewers extracted information independently. Risk of bias was evaluated with Cochrane Collaboration's tool for assessing study quality. Five randomised controlled trials were included and analysed for the result receipt rate using a random-effects model. The pooled receipt rate of HIV test results in the RVCT was significantly higher than in the SVCT (RR = 1.74, 95% CI = 1.47-2.07). Our results suggest RVCT as a favourable method to increase the receipt of HIV test results. Only two included studies assessed the modification of risk behaviour after HIV-CT in a different manner; also, the sample size was small in the current meta-analysis. In future research, it is necessary to confirm the effect of RVCT on disinhibition of post-test risk behaviour. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  7. A Novel Framework for Motion-Tolerant Instantaneous Heart Rate Estimation by Phase-Domain Multiview Dynamic Time Warping.

    Science.gov (United States)

    Zhang, Qingxue; Zhou, Dian; Zeng, Xuan

    long-term wearable instantaneous heart rate (IHR) monitoring is essential to enable pervasive heart health and fitness management. In this paper, a novel framework is proposed to robustly estimate the IHR from electrocardiogram (ECG) signals corrupted by large amounts of daily motion artifacts, which are one of the major impediments against the long-term IHR monitoring. the corrupted ECG signals are first projected to a high-dimensional phase space, where the constructed phase portraits of heartbeats are of many new geometrical properties and are expected to be powerful patterns more immune to the motion artifacts. Afterwards, a multiview dynamic time warping approach is applied on the constructed phase portraits, to effectively capture motion artifacts-induced inconsistencies and reveal heartbeats-related consistencies from corrupted signals. Finally, the phase portraits of heartbeats in the multidimensional phase space can be identified, and then, the IHR estimates are achieved. the proposed framework is evaluated on a wrist-ECG dataset acquired by a semicustomized platform and also a public ECG dataset. With a signal-to-noise ratio as low as -9 dB, the mean absolute error and root mean square error of the estimated IHR are 2.5 beats per minute (BPM) and 7.0 BPM, respectively. these results demonstrate that our framework can effectively identify the heartbeats from ECG signals continuously corrupted by intense and random motion artifacts and estimate the IHR. the proposed framework greatly outperforms previously reported approaches and is expected to contribute to long-term IHR monitoring. long-term wearable instantaneous heart rate (IHR) monitoring is essential to enable pervasive heart health and fitness management. In this paper, a novel framework is proposed to robustly estimate the IHR from electrocardiogram (ECG) signals corrupted by large amounts of daily motion artifacts, which are one of the major impediments against the long-term IHR monitoring. the

  8. Gas phase dispersion in compost as a function of different water contents and air flow rates

    Science.gov (United States)

    Sharma, Prabhakar; Poulsen, Tjalfe G.

    2009-07-01

    Gas phase dispersion in a natural porous medium (yard waste compost) was investigated as a function of gas flow velocity and compost volumetric water content using oxygen and nitrogen as tracer gases. The compost was chosen because it has a very wide water content range and because it represents a wide range of porous media, including soils and biofilter media. Column breakthrough curves for oxygen and nitrogen were measured at relatively low pore gas velocities, corresponding to those observed in for instance soil vapor extraction systems or biofilters for air cleaning at biogas plants or composting facilities. Total gas mechanical dispersion-molecular diffusion coefficients were fitted from the breakthrough curves using a one-dimensional numerical solution to the advection-dispersion equation and used to determine gas dispersivities at different volumetric gas contents. The results showed that gas mechanical dispersion dominated over molecular diffusion with mechanical dispersion for all water contents and pore gas velocities investigated. Importance of mechanical dispersion increased with increasing pore gas velocity and compost water content. The results further showed that gas dispersivity was relatively constant at high values of compost gas-filled porosity but increased with decreasing gas-filled porosity at lower values of gas-filled porosity. Results finally showed that measurement uncertainty in gas dispersivity is generally highest at low values of pore gas velocity.

  9. A rapid MCM-41 dispersive micro-solid phase extraction coupled with LC/MS/MS for quantification of ketoconazole and voriconazole in biological fluids.

    Science.gov (United States)

    Yahaya, Noorfatimah; Sanagi, Mohd Marsin; Abd Aziz, Noorizan; Wan Ibrahim, Wan Aini; Nur, Hadi; Loh, Saw Hong; Kamaruzaman, Sazlinda

    2017-02-01

    A rapid dispersive micro-solid phase extraction (D-μ-SPE) combined with LC/MS/MS method was developed and validated for the determination of ketoconazole and voriconazole in human urine and plasma samples. Synthesized mesoporous silica MCM-41 was used as sorbent in d-μ-SPE of the azole compounds from biological fluids. Important D-μ-SPE parameters, namely type desorption solvent, extraction time, sample pH, salt addition, desorption time, amount of sorbent and sample volume were optimized. Liquid chromatographic separations were carried out on a Zorbax SB-C 18 column (2.1 × 100 mm, 3.5 μm), using a mobile phase of acetonitrile-0.05% formic acid in 5 mm ammonium acetate buffer (70:30, v/v). A triple quadrupole mass spectrometer with positive ionization mode was used for the determination of target analytes. Under the optimized conditions, the calibration curves showed good linearity in the range of 0.1-10,000 μg/L with satisfactory limit of detection (≤0.06 μg/L) and limit of quantitation (≤0.3 μg/L). The proposed method also showed acceptable intra- and inter-day precisions for ketoconazole and voriconazole from urine and human plasma with RSD ≤16.5% and good relative recoveries in the range 84.3-114.8%. The MCM-41-D-μ-SPE method proved to be rapid and simple and requires a small volume of organic solvent (200 μL); thus it is advantageous for routine drug analysis. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Rapid detection of the addition of soybean proteins to cheese and other dairy products by reversed-phase perfusion chromatography.

    Science.gov (United States)

    García, M C; Marina, M L

    2006-04-01

    The undeclared addition of soybean proteins to milk products is forbidden and a method is needed for food control and enforcement. This paper reports the development of a chromatographic method for routine analysis enabling the detection of the addition of soybean proteins to dairy products. A perfusion chromatography column and a linear binary gradient of acetonitrile-water-0.1% (v/v) trifluoroacetic acid at a temperature of 60 degrees C were used. A very simple sample treatment consisting of mixing the sample with a suitable solvent (Milli-Q water or bicarbonate buffer (pH=11)) and centrifuging was used. The method enabled the separation of soybean proteins from milk proteins in less than 4 min (at a flow-rate of 3 ml/min). The method has been successfully applied to the detection of soybean proteins in milk, cheese, yogurt, and enteral formula. The correct quantitation of these vegetable proteins has also been possible in milk adulterated at origin with known sources of soybean proteins. The application of the method to samples adulterated at origin also leads to interesting conclusions as to the effect of the processing conditions used for the preparation of each dairy product on the determination of soybean proteins.

  11. INVESTIGATION INTO THE RATE OF TRIOCTYLAMINE PARTITIONING INTO THE MCU AQUEOUS PHASES

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T.; Couture, A.

    2013-07-16

    The Savannah River National Laboratory (SRNL) has examined the issue of trioctylamine (TOA) losses at the Modular Caustic-Side Solvent Extraction Unit (MCU) solvent. For this study, SRNL used partitioning and radiolysis data from the Oak Ridge National Laboratory (ORNL) as well as actual MCU operational data. From the radiolysis data, SRNL prepared a model on the rate of TOA degradation. From the combined sets of data, SRNL has calculated the largest possible value of TOA (although this value is not credible) in the Strip Effluent (SE) and also calculated two different conservative, more realistic values for TOA in the SE. Even under conservative assumptions, such as all of the TOA losses partitioning solely into the Strip Effluent (SE), the MCU operational data suggests that the maximum realistic TOA concentration in the SE is < 0.6 mg/L. Furthermore, from understanding the chemical differences between the old and new strip solutions, SRNL does not believe that the TOA will deplete from the blended BOBCalixC6 – Next Generation Solvent (NGS-MCU) at a rate higher than previously experienced. Finally, SRNL recommends pursuing analytical development of a method for TOA with a superior precision compared to the current method. However, as the TOA in the blended solvent will continuously decline during MCU operations, further improvements in the development of the understanding of TOA losses may not be cost effective.

  12. Stopping rules employing response rates, time to progression, and early progressive disease for phase II oncology trials

    Directory of Open Access Journals (Sweden)

    Goffin John R

    2011-12-01

    Full Text Available Abstract Background Response rate (RR, the most common early means of assessing oncology drugs, is not suitable as the sole endpoint for phase II trials of drugs which induce disease stability but not regression. Time to progression (TTP may be more sensitive to such agents, but induces recruitment delays in multistage studies. Early progressive disease (EPD is the earliest signal of time to progression, but is less intuitive to investigators, To study drugs with unknown anti-tumour effect, we designed the Combination Stopping Rule (CSR, which allows investigators to establish a hypothesis using RR and TTP, while the program also employs early progressive disease (EPD to assess for drug inactivity during the first stage of study accrual. Methods A computer program was created to generate stopping rules based on specified error rates, trial size, and RR and median TTP of interest and disinterest for a two-stage phase II trial. Rules were generated for stage II such that the null hypothesis (Hnul was rejected if either RR or TTP met desired thresholds, and accepted if both did not. Assuming an exponential distribution for progression, EPD thresholds were determined based on specified TTP values. Stopping rules were generated for stage I such that Hnul was accepted and the study stopped if both RR and EPD were unacceptable. Results Patient thresholds were generated for RR, median TTP, and EPD which achieved specified error rates and which allowed early stopping based on RR and EPD. For smaller proportional differences between interesting and disinteresting values of RR or TTP, larger trials are required to maintain alpha error, and early stopping is more common with a larger first stage. Conclusion Stopping rules are provided for phase II trials for drugs which have either a desirable RR or TTP. In addition, early stopping can be achieved using RR and EPD.

  13. Rapid and sensitive solid phase extraction-large volume injection-gas chromatography for the analysis of mineral oil saturated and aromatic hydrocarbons in cardboard and dried foods.

    Science.gov (United States)

    Moret, Sabrina; Barp, Laura; Purcaro, Giorgia; Conte, Lanfranco S

    2012-06-22

    A rapid off-line solid phase extraction-large volume injection-gas chromatography-flame ionisation detection (SPE-LVI-GC-FID) method, based on the use of silver silica gel and low solvent consumption, was developed for mineral oil saturated hydrocarbon (MOSH) and mineral oil aromatic hydrocarbon (MOAH) determination in cardboard and dried foods packaged in cardboard. The SPE method was validated using LVI with a conventional on-column injector and the retention gap technique (which allowed to inject up to 50 μL of the sample). Detector response was linear over all the concentration range tested (0.5-250 μg/mL), recoveries were practically quantitative, repeatability was good (coefficients of variation lower than 7%) and limit of quantification adequate to quantify the envisioned limit of 0.15 mg/kg proposed in Germany for MOAH analysis in food samples packaged in recycled cardboard. Rapid heating of the GC oven allowed to increase sample throughput (3-4 samples per hour) and to enhance sensitivity. The proposed method was used for MOSH and MOAH determination in selected food samples usually commercialised in cardboard packaging. The most contaminated was a tea sample (102.2 and 7.9 mg/kg of MOSH and MOAH below n-C25, respectively), followed by a rice and a sugar powder sample, all packaged in recycled cardboard. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. A rapid and reliable method for discriminating rice products from different regions using MCX-based solid-phase extraction and DI-MS/MS-based metabolomics approach.

    Science.gov (United States)

    Lim, Dong Kyu; Mo, Changyeun; Long, Nguyen Phuoc; Lim, Jongguk; Kwon, Sung Won

    2017-09-01

    The expansion of the global rice marketplace ultimately raises concerns about authenticity control. Several analytical methods for differentiating the geographical origin of rice have been developed, yet a high-throughput method is still in demand. In this study, we developed a rapid approach using direct infusion-mass spectrometry (DI-MS) to distinguish rice products from different countries. Specifically, the elimination of the matrix effect by a polytetrafluoroethylene (PTFE) filter, a mixed-mode cation exchange (MCX) solid-phase extraction (SPE) with 20% methanol, and an MCX SPE with 100% methanol were measured. Afterward, partial least squares discriminant analysis and random forests were applied to seek the optimal discrimination method. The results revealed that the combination of MCX SPE with 100% methanol and DI-MS in positive ion mode (accuracy=1.000, R2=0.916, Q2=0.720, B/W-based p-value=0.015) or the combination of MCX SPE with 20% methanol and targeted DI-MS/MS in positive ion mode (accuracy=1.000, R2=0.931, Q2=0.849, B/W-based p-value=0.002) showed the excellent discriminatory ability. Furthermore, differentially expressed metabolites including sodiated lysophosphatidylcholine, lysophosphatidylcholine, lysophosphatidylethanolamines and lysophosphatidylglycerol classes were found. In conclusion, our study provides a rapid and reliable platform for geographical discrimination of white rice and will contribute to the authenticity control of rice products. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A rapid, non-destructive methodology to monitor activity of sulfide-induced corrosion of concrete based on H2S uptake rate.

    Science.gov (United States)

    Sun, Xiaoyan; Jiang, Guangming; Bond, Philip L; Wells, Tony; Keller, Jurg

    2014-08-01

    Many existing methods to monitor the corrosion of concrete in sewers are either very slow or destructive measurements. To overcome these limitations, a rapid, non-invasive methodology was developed to monitor the sulfide-induced corrosion process on concrete through the measurement of the H2S uptake rates of concrete at various corrosion stages. The H2S uptake rate for a concrete coupon was determined by measuring the gaseous H2S concentrations over time in a temperature- and humidity-controlled gas-tight reactor. The reliability of this method was evaluated by carrying out repeated tests on different concrete coupons previously exposed to 50 ppm of H2S, at 30 °C and 100% relative humidity for over 32 months. The H2S uptake measurements showed good reproducibility. It was also shown that a severely corroded coupon exhibited higher sulfide uptake rates than a less corroded coupon. This could be explained by the corrosion layer in the more corroded coupon having a higher biological sulfide oxidation activity than the less corroded coupon. Additionally, temperature changes had a stronger effect on the uptake rate of the heavily corroded coupon compared to the less corroded coupon. A corrosion rate of 8.9 ± 0.5 mm/year, estimated from the H2S uptake results, agreed well with the corrosion rate observed in real sewers under similar conditions. The method could be applied to investigate important factors affecting sulfide-induced concrete corrosion, particularly temperature, fluctuating gaseous H2S concentrations, oxygen concentrations, surface pH and relative humidity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Indirect high-bandwidth stabilization of carrier-envelope phase of a high-energy, low-repetition-rate laser.

    Science.gov (United States)

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

    2016-06-13

    We demonstrate a method of stabilizing the carrier-envelope phase (CEP) of low-repetition-rate, high-energy femtosecond laser systems such as TW-PW class lasers. A relatively weak high-repetition-rate (~1 kHz) reference pulse copropagates with a low-repetition-rate (10 Hz) high-energy pulse, which are s- and p-polarized, respectively. Using a Brewster angle window, the reference pulse is separated after the power amplifier and used for feedback to stabilize its CEP. The single-shot CEP of the high-energy pulse is indirectly stabilized to 550 mrad RMS, which is the highest CEP stability ever reported for a low-repetition-rate (10-Hz) high-energy laser system. In this novel method, the feedback frequency of the reference pulse from the front-end preamplifier can be almost preserved. Thus, higher CEP stability can be realized than for lower frequencies. Of course, a reference pulse with an even higher repetition rate (e.g., 10 kHz) can be easily employed to sample and feed back CEP jitter over a broader frequency bandwidth.

  17. Maximum two-phase flow rates of subcooled nitrogen through a sharp-edged orifice

    Science.gov (United States)

    Simoneau, R. J.

    1975-01-01

    An experiment was conducted and data are presented in which subcooled liquid nitrogen was discharged through a sharp-edged orifice at flow rates near the maximum. The data covered a range of inlet stagnation pressure from slightly above saturation to twice the thermodynamic critical pressure. The data were taken along five separate inlet stagnation isotherms ranging from 0.75 to 1.035 times the thermodynamic critical temperature. The results indicate that: (1) subcooled liquids do not choke or approach maximum flow in an asymptotic manner even though the back pressure is well below saturation; (2) orifice flow coefficients are not constant as is frequently assumed. A metastable jet appears to exist which breaks down if the difference between back pressure and saturation pressure is large enough.

  18. Rapid solid-phase microwave synthesis of highly photoluminescent nitrogen-doped carbon dots for Fe3+ detection and cellular bioimaging

    Science.gov (United States)

    He, Guili; Xu, Minghan; Shu, Mengjun; Li, Xiaolin; Yang, Zhi; Zhang, Liling; Su, Yanjie; Hu, Nantao; Zhang, Yafei

    2016-09-01

    Recently, carbon dots (CDs) have been playing an increasingly important role in industrial production and biomedical field because of their excellent properties. As such, finding an efficient method to quickly synthesize a large scale of relatively high purity CDs is of great interest. Herein, a facile and novel microwave method has been applied to prepare nitrogen doped CDs (N-doped CDs) within 8 min using L-glutamic acid as the sole reaction precursor in the solid phase condition. The as-prepared N-doped CDs with an average size of 1.64 nm are well dispersed in aqueous solution. The photoluminescence of N-doped CDs is pH-sensitive and excitation-dependent. The N-doped CDs show a strong blue fluorescence with relatively high fluorescent quantum yield of 41.2%, which remains stable even under high ionic strength. Since the surface is rich in oxygen-containing functional groups, N-doped CDs can be applied to selectively detect Fe3+ with the limit of detection of 10-5 M. In addition, they are also used for cellular bioimaging because of their high fluorescent intensity and nearly zero cytotoxicity. The solid-phase microwave method seems to be an effective strategy to rapidly obtain high quality N-doped CDs and expands their applications in ion detection and cellular bioimaging.

  19. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-01-01

    Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD...... these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three...... parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ~4-6 h prior...

  20. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-01-01

    Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD...... these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three...... parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ∼4-6 h prior...

  1. A drop in the pond: the effect of rapid mass-loss on the dynamics and interaction rate of collisionless particles

    Science.gov (United States)

    Penoyre, Zephyr; Haiman, Zoltán

    2018-01-01

    In symmetric gravitating systems experiencing rapid mass-loss, particle orbits change almost instantaneously, which can lead to the development of a sharply contoured density profile, including singular caustics for collisionless systems. This framework can be used to model a variety of dynamical systems, such as accretion discs following a massive black hole merger and dwarf galaxies following violent early star formation feedback. Particle interactions in the high-density peaks seem a promising source of observable signatures of these mass-loss events (i.e. a possible EM counterpart for black hole mergers or strong gamma-ray emission from dark matter annihilation around young galaxies), because the interaction rate depends on the square of the density. We study post-mass-loss density profiles, both analytic and numerical, in idealized cases and present arguments and methods to extend to any general system. An analytic derivation is presented for particles on Keplerian orbits responding to a drop in the central mass. We argue that this case, with initially circular orbits, gives the most sharply contoured profile possible. We find that despite the presence of a set of singular caustics, the total particle interaction rate is reduced compared to the unperturbed system; this is a result of the overall expansion of the system dominating over the steep caustics. Finally, we argue that this result holds more generally, and the loss of central mass decreases the particle interaction rate in any physical system.

  2. Determination of rate constants and equilibrium constants for solution-phase drug-protein interactions by ultrafast affinity extraction.

    Science.gov (United States)

    Zheng, Xiwei; Li, Zhao; Podariu, Maria I; Hage, David S

    2014-07-01

    A method was created on the basis of ultrafast affinity extraction to determine both the dissociation rate constants and equilibrium constants for drug-protein interactions in solution. Human serum albumin (HSA), an important binding agent for many drugs in blood, was used as both a model soluble protein and as an immobilized binding agent in affinity microcolumns for the analysis of free drug fractions. Several drugs were examined that are known to bind to HSA. Various conditions to optimize in the use of ultrafast affinity extraction for equilibrium and kinetic studies were considered, and several approaches for these measurements were examined. The dissociation rate constants obtained for soluble HSA with each drug gave good agreement with previous rate constants reported for the same drugs or other solutes with comparable affinities for HSA. The equilibrium constants that were determined also showed good agreement with the literature. The results demonstrated that ultrafast affinity extraction could be used as a rapid approach to provide information on both the kinetics and thermodynamics of a drug-protein interaction in solution. This approach could be extended to other systems and should be valuable for high-throughput drug screening or biointeraction studies.

  3. Determination of glomerular filtration rate (GFR) from fractional renal accumulation of iodinated contrast material: a convenient and rapid single-kidney CT-GFR technique.

    Science.gov (United States)

    Yuan, XiaoDong; Tang, Wei; Shi, WenWei; Yu, Libao; Zhang, Jing; Yuan, Qing; You, Shan; Wu, Ning; Ao, Guokun; Ma, Tingting

    2018-02-09

    To develop a convenient and rapid single-kidney CT-GFR technique. One hundred and twelve patients referred for multiphasic renal CT and 99mTc-DTPA renal dynamic imaging Gates-GFR measurement were prospectively included and randomly divided into two groups of 56 patients each: the training group and the validation group. On the basis of the nephrographic phase images, the fractional renal accumulation (FRA) was calculated and correlated with the Gates-GFR in the training group. From this correlation a formula was derived for single-kidney CT-GFR calculation, which was validated by a paired t test and linear regression analysis with the single-kidney Gates-GFR in the validation group. In the training group, the FRA (x-axis) correlated well (r = 0.95, p < 0.001) with single-kidney Gates-GFR (y-axis), producing a regression equation of y = 1665x + 1.5 for single-kidney CT-GFR calculation. In the validation group, the difference between the methods of single-kidney GFR measurements was 0.38 ± 5.57 mL/min (p = 0.471); the regression line is identical to the diagonal (intercept = 0 and slope = 1) (p = 0.727 and p = 0.473, respectively), with a standard deviation of residuals of 5.56 mL/min. A convenient and rapid single-kidney CT-GFR technique was presented and validated in this investigation. • The new CT-GFR method takes about 2.5 min of patient time. • The CT-GFR method demonstrated identical results to the Gates-GFR method. • The CT-GFR method is based on the fractional renal accumulation of iodinated CM. • The CT-GFR method is achieved without additional radiation dose to the patient.

  4. A closed-form solution for moving source localization using LBI changing rate of phase difference only

    Directory of Open Access Journals (Sweden)

    Zhang Min

    2014-04-01

    Full Text Available Due to the deficiencies in the conventional multiple-receiver localization systems based on direction of arrival (DOA such as system complexity of interferometer or array and amplitude/phase unbalance between multiple receiving channels and constraint on antenna configuration, a new radiated source localization method using the changing rate of phase difference (CRPD measured by a long baseline interferometer (LBI only is studied. To solve the strictly nonlinear problem, a two-stage closed-form solution is proposed. In the first stage, the DOA and its changing rate are estimated from the CRPD of each observer by the pseudolinear least square (PLS method, and then in the second stage, the source position and velocity are found by another PLS minimization. The bias of the algorithm caused by the correlation between the measurement matrix and the noise in the second stage is analyzed. To reduce this bias, an instrumental variable (IV method is derived. A weighted IV estimator is given in order to reduce the estimation variance. The proposed method does not need any initial guess and the computation is small. The Cramer–Rao lower bound (CRLB and mean square error (MSE are also analyzed. Simulation results show that the proposed method can be close to the CRLB with moderate Gaussian measurement noise.

  5. Validation of the generalized model of two-phase thermosyphon loop based on experimental measurements of volumetric flow rate

    Directory of Open Access Journals (Sweden)

    Bieliński Henryk

    2016-09-01

    Full Text Available The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the lower vertical section and a condenser on the upper vertical section. The one-dimensional homogeneous and separated two-phase flow models were used in calculations. The latest minichannel heat transfer correlations available in literature were applied. A numerical analysis of the volumetric flow rate in the steady-state has been done. The experiment was conducted on a specially designed test apparatus. Ultrapure water was used as a working fluid. The results show that the theoretical predictions are in good agreement with the measured volumetric flow rate at steady-state.

  6. Validation of the generalized model of two-phase thermosyphon loop based on experimental measurements of volumetric flow rate

    Science.gov (United States)

    Bieliński, Henryk

    2016-09-01

    The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the lower vertical section and a condenser on the upper vertical section. The one-dimensional homogeneous and separated two-phase flow models were used in calculations. The latest minichannel heat transfer correlations available in literature were applied. A numerical analysis of the volumetric flow rate in the steady-state has been done. The experiment was conducted on a specially designed test apparatus. Ultrapure water was used as a working fluid. The results show that the theoretical predictions are in good agreement with the measured volumetric flow rate at steady-state.

  7. The Effect of a Rapid Heating Rate, Mechanical Vibration and Surfactant Chemistry on the Structure–Property Relationships of Epoxy/Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    Kevin Magniez

    2013-08-01

    Full Text Available The role of processing conditions and intercalant chemistry in montmorillonite clays on the dispersion, morphology and mechanical properties of two epoxy/clay nanocomposite systems was investigated in this paper. This work highlights the importance of employing complementary techniques (X-ray diffraction, small angle X-ray scattering, optical microscopy and transmission electron microscopy to correlate nanomorphology to macroscale properties. Materials were prepared using an out of autoclave manufacturing process equipped to generate rapid heating rates and mechanical vibration. The results suggested that the quaternary ammonium surfactant on C30B clay reacted with the epoxy during cure, while the primary ammonium surfactant (I.30E catalysed the polymerisation reaction. These effects led to important differences in nanocomposite clay morphologies. The use of mechanical vibration at 4 Hz prior to matrix gelation was found to facilitate clay dispersion and to reduce the area fraction of I.30E clay agglomerates in addition to increasing flexural strength by over 40%.

  8. Barley Leaf Area and Leaf Growth Rates Are Maximized during the Pre-Anthesis Phase

    Directory of Open Access Journals (Sweden)

    Ahmad M. Alqudah

    2015-04-01

    Full Text Available Leaf developmental traits are an important component of crop breeding in small-grain cereals. Surprisingly, little is known about the genetic basis for the differences in barley (Hordeum vulgare L. leaf development. The two barley row-type classes, i.e., two- and six-rowed, show clear-cut differences in leaf development. To quantify these differences and to measure the genetic component of the phenotypic variance for the leaf developmental differences in both row-type classes we investigated 32 representative spring barley accessions (14 two- and 18 six-rowed accessions under three independent growth conditions. Leaf mass area is lower in plants grown under greenhouse (GH conditions due to fewer, smaller, and lighter leaf blades per main culm compared to pot- and soil-grown field plants. Larger and heavier leaf blades of six-rowed barley correlate with higher main culm spike grain yield, spike dry weight, and harvest index; however, smaller leaf area (LA in two-rowed barley can be attributed to more spikes, tillers, and biological yield (aboveground parts. In general, leaf growth rate was significantly higher between awn primordium and tipping stages. Moderate to very high broad-sense heritabilities (0.67–0.90 were found under all growth conditions, indicating that these traits are predominantly genetically controlled. In addition, our data suggests that GH conditions are suitable for studying leaf developmental traits. Our results also demonstrated that LA impacts single plant yield and can be reconsidered in future breeding programs. Six-rowed spike 1 (Vrs1 is the major determinate of barley row-types, the differences in leaf development between two- and six-rowed barleys may be attributed to the regulation of Vrs1 in these two classes, which needs further testing.

  9. Effects of rapid aging and lower participation rate among younger adults on the short-term trend of physical activity in the National Health and Nutrition Survey, Japan.

    Science.gov (United States)

    Nishi, Nobuo; Yoshizawa, Takeshi; Okuda, Nagako

    2017-10-01

    The National Health and Nutrition Survey, Japan, has annually monitored two indicators of physical activity in adults. They are contrasting in the association with age; the prevalence of exercise habit is lower and step counts are higher among younger participants. The present study aimed to examine the effects of rapid aging of the Japanese population and the lower participation rate among younger adults on the short-term trend of two indicators of physical activity using tabulated data. The prevalence of exercise habit and step counts by age groups (≥20 years) from 2003 to 2010 were estimated using tabulated data from the National Health and Nutrition Survey by calculating sex-specific means weighted by age-specific Japanese population data for each year (population-weighted estimates) and for a fixed year (2005; age-standardized estimates). Linear regression analyses were used to test the statistical significance of their trends. Statistically significant increasing trends in the prevalence of exercise habit were observed for the crude means (P = 0.029), the population-weighted estimates (P = 0.007) and the age-standardized estimates (P = 0.016) only in men. Statistically significant decreasing trends in the step counts were observed for the crude means (P = 0.006 in men and P = 0.033 in women) and the population-weighted estimates (P = 0.008 in men and P = 0.049 in women) both in men and women, but for the age-standardized estimates (P = 0.039) only in men. The effects of rapid aging of the Japanese population and the lower participation rate among younger adults on the short-term trend are not small, and age-standardization is necessary to observe even the short-term trend of physical activity data. Geriatr Gerontol Int 2017; 17: 1677-1682. © 2017 Japan Geriatrics Society.

  10. Rapid Evolutionary Rates and Unique Genomic Signatures Discovered in the First Reference Genome for the Southern Ocean Salp, Salpa thompsoni (Urochordata, Thaliacea).

    Science.gov (United States)

    Jue, Nathaniel K; Batta-Lona, Paola G; Trusiak, Sarah; Obergfell, Craig; Bucklin, Ann; O'Neill, Michael J; O'Neill, Rachel J

    2016-10-30

    A preliminary genome sequence has been assembled for the Southern Ocean salp, Salpa thompsoni (Urochordata, Thaliacea). Despite the ecological importance of this species in Antarctic pelagic food webs and its potential role as an indicator of changing Southern Ocean ecosystems in response to climate change, no genomic resources are available for S. thompsoni or any closely related urochordate species. Using a multiple-platform, multiple-individual approach, we have produced a 318,767,936-bp genome sequence, covering >50% of the estimated 602 Mb (±173 Mb) genome size for S. thompsoni Using a nonredundant set of predicted proteins, >50% (16,823) of sequences showed significant homology to known proteins and ∼38% (12,151) of the total protein predictions were associated with Gene Ontology functional information. We have generated 109,958 SNP variant and 9,782 indel predictions for this species, serving as a resource for future phylogenomic and population genetic studies. Comparing the salp genome to available assemblies for four other urochordates, Botryllus schlosseri, Ciona intestinalis, Ciona savignyi and Oikopleura dioica, we found that S. thompsoni shares the previously estimated rapid rates of evolution for these species. High mutation rates are thus independent of genome size, suggesting that rates of evolution >1.5 times that observed for vertebrates are a broad taxonomic characteristic of urochordates. Tests for positive selection implemented in PAML revealed a small number of genes with sites undergoing rapid evolution, including genes involved in ribosome biogenesis and metabolic and immune process that may be reflective of both adaptation to polar, planktonic environments as well as the complex life history of the salps. Finally, we performed an initial survey of small RNAs, revealing the presence of known, conserved miRNAs, as well as novel miRNA genes; unique piRNAs; and mature miRNA signatures for varying developmental stages. Collectively, these

  11. A New Approach for Estimating Background Rates of Erosion Using Concentration of Meteoric 10-Be Adhered to River Sediment: Application to the Rapidly Eroding Waipaoa Basin, New Zealand

    Science.gov (United States)

    Reusser, L. J.; Bierman, P. R.; Pavich, M.; Finkel, R.

    2007-12-01

    New and existing data suggest that the concentration of atmospherically- produced, meteoric 10-Be adhered to river sediment provides a proxy for basin-scale erosion rates. Although the widely applied method of analyzing in situ produced 10-Be in river sediments has proven useful for estimating pre-anthropogenic rates of erosion in a variety of environments, there are lithologic limitation. In contrast, measuring the concentration of meteoric 10-Be adhered to river sediment allows erosion rate analysis in landscapes underlain by quartz-deficient or fine-grained lithologies, as well as in basins where the concentration of quartz varies spatially. By assuming that basins are in an overall isotopic steady-state, that erosion is rapid enough that decay is negligible, and that the integrated delivery rate of 10-Be from the atmosphere (D10-Be) can be estimated, basin-scale mass loss rates (Ms) can be solved by equating the 10-Be flux in from the atmosphere with the flux of 10-Be out of the basin on sediment (C10-Be) and expressed as sediment yield per unit area (Ys). Fin = Fout D10-Be * A = Ms * C10-Be Ms = (D10-Be * A)/ C10-Be Ys = D10-Be / C10-Be To validate this new approach, we examined the limited data that do exist and found reasonable correspondence between erosion rates estimated from meteoric 10-Be concentrations and estimated by other means. As a first application, we use meteoric 10-Be in river sediment to estimate basin-scale erosion rates from catchments within and near the mud-stone dominated Waipaoa River Basin draining the tectonically active east coast of New Zealand's North Island. Near total conversion of indigenous forest to pasture over the past century in the Waipaoa Basin has resulted in some of the most dramatic and widespread erosional features on the planet, and contemporary sediment yields that rank among the highest in the world (~7 million kg/(km2 * yr)). The amount of meteoric 10-Be adhered to eight river sediment samples suggests that modern

  12. Solid-phase microextraction low temperature plasma mass spectrometry for the direct and rapid analysis of chemical warfare simulants in complex mixtures.

    Science.gov (United States)

    Dumlao, Morphy C; Jeffress, Laura E; Gooding, J Justin; Donald, William A

    2016-06-21

    Solid-phase microextraction (SPME) is directly integrated with low temperature plasma ionisation mass spectrometry to rapidly detect organophosphate chemical warfare agent simulants and their hydrolysis products in chemical mixtures, including urine. In this sampling and ionization method, the fibre serves: (i) to extract molecules from their native environment, and (ii) as the ionization electrode that is used to desorb and ionize molecules directly from the SPME surface. By use of a custom fabricated SPME fibre consisting of a stainless steel needle coated with a Linde Type A (LTA) zeolitic microporous material and low temperature plasma mass spectrometry, protonated dimethyl methylphosphonate (DMMP), diethyl ethylphosphonate (DEEP) and pinacolyl methylphosphonic acid (PinMPA) can be detected at less than 100 ppb directly in water and urine. Organophosphates were not readily detected by this approach using an uncoated needle in negative control experiments. The use of the LTA coating significantly outperformed the use of a high alumina Zeolite Socony Mobil-5 (ZSM-5) coating of comparable thickness that is significantly less polar than LTA. By conditioning the LTA probe by immersion in an aqueous CuSO4 solution, the ion abundance for protonated DMMP increased by more than 300% compared to that obtained without any conditioning. Sample recovery values were between 96 and 100% for each analyte. The detection of chemical warfare agent analogues and hydrolysis products required less than 2 min per sample. A key advantage of this sampling and ionization method is that analyte ions can be directly and rapidly sampled from chemical mixtures, such as urine and seawater, without sample preparation or chromatography for sensitive detection by mass spectrometry. This ion source should prove beneficial for portable mass spectrometry applications because relatively low detection limits can be obtained without the use of compressed gases, fluid pumps, and lasers. Moreover, the

  13. [Rapid screening of fipronil and its metabolites in egg and egg products by solid phase extraction-liquid chromatography-quadrupole time-of-flight mass spectrometry].

    Science.gov (United States)

    Guo, Dehua; Shi, Yiyin; Li, You; Yi, Xionghai; Deng, Xiaojun; Xiao, Wenqing; Wang, Jian; Li, Xiao; Liu, Han; Shen, Weijian

    2017-12-08

    A method for rapid screening of fipronil and its metabolites in egg and egg products was developed by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QTOF MS). The samples were extracted by acid-acetonitrile, cleaned up by PRiME HLB SPE. The separation was performed on a Poroshell 120 EC C18 column (150 mm×3 mm, 2.7 μm) with gradient elution using water and acetonitrile as mobile phases. The target compounds were monitored under negative ionization mode with electrospray ionization (ESI) source and two databases of accurate mass and fragment ions were created. The matrix effects in four kinds of egg and egg products were considered and the quantification was carried out by internal standard method. The results demonstrated that the linear ranges were from 0.1 to 5 μg/L with good correlation coefficients (r2>0.99). The limits of detection (LODs, S/N>3) and limits of quantitation (LOQs, S/N>10) were 0.2 μg/kg and 1 μg/kg, respectively. The recoveries of fipronil and its metabolites in different matrixes spiked with 1, 2 and 5 μg/kg varied from 82.6%-98.1%, and the relative standard deviations (RSDs) were between 3.8%-9.9% (n=6). The method can effectively correct the ionization suppression. It is sensitive, accurate and suitable for the rapid screening of fipronil, fipronil sulfide, fipronil sulfone and fipronil desulfinyl in egg, egg noodle, cake and mayonnaise.

  14. Galaxy secular mass flow rate determination using the potential-density phase shift approach: Application to six nearby spiral galaxies

    Science.gov (United States)

    Zhang, Xiaolei; Buta, Ronald J.

    2015-01-01

    Using the potential-density phase shift approach developed by the present authors in earlier publications, we estimate the magnitude of radial mass accretion/excretion rates across the disks of six nearby spiral galaxies (NGC 628, NGC 3351, NGC 3627, NGC 4321, NGC 4736, and NGC 5194) having a range of Hubble types. Our goal is to examine these rates in the context of bulge building and secular morphological evolution along the Hubble sequence. Stellar surface density maps of the sample galaxies are derived from SINGS 3.6 μm and SDSS i-band images using colors as an indicator of mass-to-light ratios. Corresponding molecular and atomic gas surface densities are derived from published CO (1-0) and HI interferometric observations of the BIMA SONG, THINGS, and VIVA surveys. The mass flow rate calculations utilize a volume-type torque integral to calculate the angular momentum exchange rate between the basic state disk matter and what we assume to be density wave modes in the observed galaxies. This volume-type integral contains the contributions from both the gravitational surface torque couple and the advective surface torque couple at the nonlinear, quasi-steady state of the wave modes, in sharp contrast to its behavior in the linear regime, where it contains only the contribution from the gravitational surface torque couple used by Lynden-Bell & Kalnajs in 1972. The potential-density phase shift approach yields angular momentum transport rates several times higher than those estimated using the Lynden-Bell and Kalnajs approach. And unlike Lynden-Bell and Kalnajs, whose approach predicts zero mass redistribution across the majority of the disk surface (apart from the isolated locations of wave-particle resonances) for quasi-steady waves, the current approach leads to predictions of significant mass redistribution induced by the quasi-steady density wave modes, enough for the morphological types of disks to evolve substantially within its lifetime. This difference

  15. Achieving rapid Li-ion insertion kinetics in TiO2 mesoporous nanotube arrays for bifunctional high-rate energy storage smart windows.

    Science.gov (United States)

    Tong, Zhongqiu; Liu, Shikun; Li, Xingang; Mai, Liqiang; Zhao, Jiupeng; Li, Yao

    2018-01-31

    Smart electrochromic windows integrated with electrochemical energy storage capacity are receiving increasing interest for green buildings. However, the fabrication of bifunctional devices that demonstrate high-rate capability with stable and desirable optical modulation still remains a great challenge. Herein, a facile sacrificial template-accelerated hydrolysis approach is presented to prepare a designed lithium-ion insertion-type material layer on a fluorine-doped tin oxide substrate, with TiO2 mesoporous nanotube array (MNTA) film as an example, with rapid Li-ion insertion kinetics and without sacrificing window transparency, to meet requirements. A bifunctional device is assembled to exhibit the optical-electrochemical superiority of MNTA nanostructures. The as-assembled bifunctional smart window exhibits strong electrochromic contrast and high-rate capability in the fast galvanostatic charge/discharge process. For instance, at 1 A g-1, it completes the charge or discharge process within only 232 s and delivers a high, reversible and stable specific capacity of 60 mA h g-1, accompanying obvious transmittance modulation in the visible spectrum, with a typical value of ca. 30.4% at 700 nm, and strong color changes between deep blue and transparency.

  16. Influence of Heating Rate on Ferrite Recrystallization and Austenite Formation in Cold-Rolled Microalloyed Dual-Phase Steels

    Science.gov (United States)

    Philippot, C.; Bellavoine, M.; Dumont, M.; Hoummada, K.; Drillet, J.; Hebert, V.; Maugis, P.

    2017-11-01

    Compared with other dual-phase (DP) steels, initial microstructures of cold-rolled martensite-ferrite have scarcely been investigated, even though they represent a promising industrial alternative to conventional ferrite-pearlite cold-rolled microstructures. In this study, the influence of the heating rate (over the range of 1 to 10 K/s) on the development of microstructures in a microalloyed DP steel is investigated; this includes the tempering of martensite, precipitation of microalloying elements, recrystallization, and austenite formation. This study points out the influence of the degree of ferrite recrystallization prior to the austenite formation, as well as the importance of the cementite distribution. A low heating rate giving a high degree of recrystallization, leads to the formation of coarse austenite grains that are homogenously distributed in the ferrite matrix. However, a high heating rate leading to a low recrystallization degree, results in a banded-like structure with small austenite grains surrounded by large ferrite grains. A combined approach, involving relevant multiscale microstructural characterization and modeling to rationalize the effect of the coupled processes, highlights the role of the cold-worked initial microstructure, here a martensite-ferrite mixture: recrystallization and austenite formation commence in the former martensite islands before extending in the rest of the material.

  17. Optimization and phase matching of fiber-laser-driven high-order harmonic generation at high repetition rate.

    Science.gov (United States)

    Cabasse, Amélie; Machinet, Guillaume; Dubrouil, Antoine; Cormier, Eric; Constant, Eric

    2012-11-15

    High-repetition-rate sources are very attractive for high-order harmonic generation (HHG). However, due to their pulse characteristics (low energy, long duration), those systems require a tight focusing geometry to achieve the necessary intensity to generate harmonics. In this Letter, we investigate theoretically and experimentally the optimization of HHG in this geometry, to maximize the extreme UV (XUV) photon flux and improve the conversion efficiency. We analyze the influence of atomic gas media (Ar, Kr, or Xe), gas pressure, and interaction geometries (a gas jet and a finite and a semi-infinite gas cell). Numerical simulations allow us to define optimal conditions for HHG in this tight focusing regime and to observe the signature of on-axis phase matching. These conditions are implemented experimentally using a high-repetition-rate Yb-doped fiber laser system. We achieve optimization of emission with a recorded XUV photon flux of 4.5×10(12) photons/s generated in Xe at 100 kHz repetition rate.

  18. Rapid monitoring of iron-chelating therapy in thalassemia major by a new cardiovascular MR measure: the reduced transverse relaxation rate

    Science.gov (United States)

    Kim, Daniel; Jensen, Jens H.; Wu, Ed X.; Feng, Li; Au, Wing-Yan; Cheung, Jerry S.; Ha, Shau-Yin; Sheth, Sujit S.; Brittenham, Gary M.

    2011-01-01

    In iron overload, almost all the excess iron is stored intracellularly as rapidly mobilizable ferritin iron and slowly exchangeable hemosiderin iron. Increases in cytosolic iron may produce oxidative damage that ultimately results in cardiomyocyte dysfunction. Because intracellular ferritin iron is evidently in equilibrium with the low-molecular-weight cytosolic iron pool, measurements of ferritin iron potentially provide a clinically useful indicator of changes in cytosolic iron. The cardiovascular magnetic resonance (CMR) index of cardiac iron used clinically, the effective transverse relaxation rate (R2*), is principally influenced by hemosiderin iron and changes only slowly over several months, even with intensive iron-chelating therapy. Another conventional CMR index of cardiac iron, the transverse relaxation rate (R2), is sensitive to both hemosiderin iron and ferritin iron. We have developed a new MRI measure, the ‘reduced transverse relaxation rate’ (RR2), and have proposed in previous studies that this measure is primarily sensitive to ferritin iron and largely independent of hemosiderin iron in phantoms mimicking ferritin iron and human liver explants. We hypothesized that RR2 could detect changes produced by 1 week of iron-chelating therapy in patients with transfusion-dependent thalassemia. We imaged 10 patients with thalassemia major at 1.5 T in mid-ventricular short-axis planes of the heart, initially after suspending iron-chelating therapy for 1 week and subsequently after resuming oral deferasirox. After resuming iron-chelating therapy, significant decreases were observed in the mean myocardial RR2 (7.8%, p 0.90). Although the difference between changes in RR2 and R2 was not significant (p > 0.3), RR2 was consistently more sensitive than R2 (and R2*) to the resumption of iron-chelating therapy, as judged by the effect sizes of relaxation rate differences detected. Although further studies are needed, myocardial RR2 may be a promising

  19. Phase Engineering of Perovskite Materials for High-Efficiency Solar Cells: Rapid Conversion of CH3NH3PbI3to Phase-Pure CH3NH3PbCl3via Hydrochloric Acid Vapor Annealing Post-Treatment.

    Science.gov (United States)

    Zhou, Weiran; Zhou, Pengcheng; Lei, Xunyong; Fang, Zhimin; Zhang, Mengmeng; Liu, Qing; Chen, Tao; Zeng, Hualing; Ding, Liming; Zhu, Jun; Dai, Songyuan; Yang, Shangfeng

    2018-01-17

    Organometal halide CH 3 NH 3 PbI 3 (MAPbI 3 ) has been commonly used as the light absorber layer of perovskite solar cells (PSCs), and, especially, another halide element chlorine (Cl) has been often incorporated to assist the crystallization of perovskite film. However, in most cases, a predominant MAPbI 3 phase with trace of Cl - is obtained ultimately and the role of Cl involvement remains unclear. Herein, we develop a low-cost and facile method, named hydrochloric acid vapor annealing (HAVA) post-treatment, and realize a rapid conversion of MAPbI 3 to phase-pure MAPbCl 3 , demonstrating a new concept of phase engineering of perovskite materials toward efficiency enhancement of PSCs for the first time. The average grain size of perovskite film after HAVA post-treatment increases remarkably through an Ostwald ripening process, leading to a denser and smoother perovskite film with reduced trap states and enhanced crystallinity. More importantly, the generation of MAPbCl 3 secondary phase via phase engineering is beneficial for improving the carrier mobility with a more balanced carrier transport rate and enlarging the band gap of perovskite film along with optimized energy level alignment. As a result, under the optimized HAVA post-treatment time (2 min), we achieved a significant enhancement of the power conversion efficiency (PCE) of the MAPbI 3 -based planar heterojunction-PSC device from 14.02 to 17.40% (the highest PCE reaches 18.45%) with greatly suppressed hysteresis of the current-voltage response.

  20. Significant Treatment Effect of Bupropion in Patients With Bipolar Disorder but Similar Phase-Shifting Rate as Other Antidepressants

    Science.gov (United States)

    Li, Dian-Jeng; Tseng, Ping-Tao; Chen, Yen-Wen; Wu, Ching-Kuan; Lin, Pao-Yen

    2016-01-01

    Abstract Bupropion is widely used for treating bipolar disorder (BD), and especially those with depressive mood, based on its good treatment effect, safety profile, and lower risk of phase shifting. However, increasing evidence indicates that the safety of bupropion in BD patients may not be as good as previously thought. The aim of this study was to summarize data on the treatment effect and safety profile of bupropion in the treatment of BD via a meta-analysis. Electronic search through PubMed and ClinicalTrials.gov was performed. The inclusion criteria were: (i) studies comparing changes in disease severity before and after bupropion treatment or articles comparing the treatment effect of bupropion in BD patients with those receiving other standard treatments; (ii) articles on clinical trials in humans. The exclusion criteria were (i) case reports/series, and (ii) nonclinical trials. All effect sizes from 10 clinical trials were pooled using a random effects model. We examined the possible confounding variables using meta-regression and subgroup analysis. Bupropion significantly improved the severity of disease in BD patients (P bupropion and those who received other antidepressants. We could not perform a detailed meta-analysis of every category of antidepressant, nor could we rule out the possible confounding effect of concurrent psychotropics or include all drug side effects. Furthermore, the number of studies recruited in the meta-analysis was relatively small. Our findings reconfirm the benefits of bupropion for the treatment of bipolar depression, which are similar to those of other antidepressants. However, the rate of phase shifting with bupropion usage was not as low compared to other antidepressants as previously thought, which should serve to remind clinicians of the risk of phase shifting when prescribing bupropion to BD patients regardless of the suggestions of current clinical practice guidelines. PMID:27043678

  1. Decomposition reaction rate of BCl3-C3H6(propene)-H2 in the gas phase.

    Science.gov (United States)

    Xiao, Jun; Su, Kehe; Liu, Yan; Ren, Hongjiang; Zeng, Qingfeng; Cheng, Laifei; Zhang, Litong

    2012-07-05

    The decomposition reaction rate in the BCl(3)-C(3)H(6)-H(2) gas phase reaction system in preparing boron carbides was investigated based on the most favorable reaction pathways proposed by Jiang et al. [Theor. Chem. Accs. 2010, 127, 519] and Yang et al. [J. Theor. Comput. Chem. 2012, 11, 53]. The rate constants of all the elementary reactions were evaluated with the variational transition state theory. The vibrational frequencies for the stationary points as well as the selected points along the minimum energy paths (MEPs) were calculated with density functional theory at the B3PW91/6-311G(d,p) level and the energies were refined with the accurate model chemistry method G3(MP2). For the elementary reaction associated with a transition state, the MEP was obtained with the intrinsic reaction coordinates, while for the elementary reaction without transition state, the relaxed potential energy surface scan was employed to obtain the MEP. The rate constants were calculated for temperatures within 200-2000 K and fitted into three-parameter Arrhenius expressions. The reaction rates were investigated by using the COMSOL software to solve numerically the coupled differential rate equations. The results show that the reactions are, consistent with the experiments, appropriate at 1100-1500 K with the reaction time of 30 s for 1100 K, 1.5 s for 1200 K, 0.12 s for 1300 K, 0.011 s for 1400 K, or 0.001 s for 1500 K, for propene being almost completely consumed. The completely dissociated species, boron carbides C(3)B, C(2)B, and CB, have very low concentrations, and C(3)B is the main product at higher temperatures, while C(2)B is the main product at lower temperatures. For the reaction time 1 s, all these concentrations approach into a nearly constant. The maximum value (in mol/m(3)) is for the highest temperature 1500 K with the orders of -13, -17, and -23 for C(3)B, C(2)B, and CB, respectively. It was also found that the logarithm of the overall reaction rate and reciprocal

  2. Fluid-phase endocytosis does not contribute to rapid fluid secretion in the malpighian tubules of the house cricket, Acheta domesticus.

    Science.gov (United States)

    Hazelton, S Renee; Spring, Jeffrey H; Felgenhauer, Bruce E

    2002-01-01

    When the Malpighian tubules (Mt) of the house cricket (Acheta domesticus) are treated with dibutyryl adenosine 3', 5'-cyclic monophosphate (db-cAMP; 1 mM), which causes a doubling in secretion rate, more than 50% of the cell volume is occupied by vesicles within 420 sec of exposure. In view of the fact that the increase in vesiculation occurs concomitantly with stimulated fluid transport, we set out to determine whether the vesicles are formed as a result of fluid-phase endocytosis (pinocytosis) and subsequently used to transport fluid to the lumen as one means of increasing transport rate. We used fluorescent fluid-phase markers (Lucifer Yellow Carbohydrazide [LYCH] and Alexa 488 hydrazide) and an electron dense marker (cationized ferritin) to elucidate the degree of endocytosis that occurred with db-cAMP stimulation. We found that, although some fluid is taken into the cells of the mid-tubule via endocytosis, it does not coincide with the level of vacuolation present in stimulated tubules. The amount of LYCH transported into the primary urine by the db-cAMP-stimulated Mt decreased by 40% as compared to the unstimulated transport, and the rate of transport of LYCH was only 30% of the unstimulated tubules. In summary, our findings do not support the theory that the majority of the vesicles or vacuoles comprise intracellular, endocytotic compartments formed via a basolateral endocytotic pathway. We also found no evidence to support the functioning of vesicles or vacuoles as transcellular "shuttling" mechanisms to move fluid from the basal region to the apical membrane and into the lumen. Copyright 2002 Wiley-Liss, Inc.

  3. Effect of cooling rate during solidification on the hard phases of M23C6-type of cast CoCrMo alloy

    Directory of Open Access Journals (Sweden)

    M. Alvarez-Vera

    2016-07-01

    Full Text Available Microstructural morphology of CoCrMo alloy by control of the cooling rate during the solidification was investigated. Samples were obtained using both an induction furnace for slow cooling rate and electric arc furnace for fast cooling rate. Microstructural characterizations were performed with metallographic techniques. It was found that the difference between the formation temperature of hard secondary phases of M23C6-type carbides determine the reduction of carbide size by increasing the cooling rate.

  4. A rapid, solid phase extraction (SPE technique for the extraction and gas chromatographic determination lindane pesticide residue in tissue and milk

    Directory of Open Access Journals (Sweden)

    Yuningsih

    2006-03-01

    Full Text Available Organochlorine pesticide contamination in feed can cause residue in animal product (tissue and milk, so its become a problem in food safety. Solid phase extraction (SPE has been carried out for determination organochlorine pesticide residues in food animal production. The technique was rapid, not costly and produce limited amount of hazardous-waste. Samples were homogenized with acetonitrile trough cartridge C18, eluted in fluorocyl column with 2% ether-petroleum or acetonitrile fortissue and milk samples respectively. The recoveries of tissue sample by addition lindane standard solution: 0.50 and 1.00 μg are 85.10 and 103.10% respectively, while that of milk with the addition of 0.50, 1.00 and 1.50 μg are 83.80, 88.69 and 91.24% respectively. Three replicates were carried out for every sample. According of validation criteria of FAO/IAEA the recovery for analysis of pesticide residues was 70-110%. Therefore, the method is applicable.

  5. In Vivo Selective Capture and Rapid Identification of Luteolin and Its Metabolites in Rat Livers by Molecularly Imprinted Solid-Phase Microextraction.

    Science.gov (United States)

    Gao, Die; Wang, Dan-Dan; Zhang, Qian; Yang, Feng-Qing; Xia, Zhi-Ning; Zhang, Qi-Hui; Yuan, Chun-Su

    2017-02-15

    A method based on molecularly imprinted solid-phase microextraction (MIP-SPME) coupled with liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) was developed for the detection of luteolin and its metabolites in vivo. The MIP-SPME fibers were first fabricated by dopamine and silane, and then luteolin MIPs-coated fibers were successfully prepared using luteolin, acrylamide (AM), and ethylene glycol dimethacrylate (EGDMA) as the template, functional monomer and cross-linker, respectively. The characterizations of polymers were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and the Brunauer-Emmett-Teller method (BET). The properties involving adsorption and selective experiments were evaluated, and these results revealed that MIP fibers presented high adsorption capacity and selectivity to luteolin. Furthermore, the developed MIP-SPME coupled with the LC-QTOF-MS/MS method was adopted to capture and identify luteolin and its metabolites in rat livers in vivo, and eventually, apigenin, chrysoeriol, and diosmetin were rapidly identified as metabolites.

  6. Rapid determination of endogenous cytokinins in plant samples by combination of magnetic solid phase extraction with hydrophilic interaction chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Liu, Zhao; Cai, Bao-Dong; Feng, Yu-Qi

    2012-04-01

    A 2-acrylamido-2-methyl-1-propanesulfonic acid-co-ethylene glycol dimethacrylate (Fe₃O₄/SiO₂/P(AMPS-co-EGDMA)) copolymer was prepared and used as a magnetic solid phase extraction (MSPE) medium for recovery of endogenous cytokinins (CKs) from plant extracts. This magnetic porous polymer was characterized by electron microscopy, nitrogen sorption experiments, elemental analysis and Fourier-transformed infrared spectroscopy. It was demonstrated to have high extraction capacity toward CKs in plants due to its specificity, surface area and porous structure. Coupled with hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS), a rapid, simple, and effective MSPE-HILIC-MS/MS analytical method for the quantitative analysis of endogenous CKs in Oryza sativa (O. sativa) roots was successfully established. Good linearities were obtained for all CKs investigated with correlation coefficients (R²>0.9975. The results showed that LODs (S/N=3) were ranged from 0.18 to 3.65 pg mL⁻¹. Reproducibility of the method was obtained with intra-day and inter-day relative standard deviations (RSDs) less than 16.1% and the recoveries in plant samples ranged from 72.8% to 115.5%. Finally, the MSPE-HILIC-MS/MS method was applied to several plant samples, and the amounts of endogenous CKs in O. sativa roots, leaves and Arabidopsis thaliana (A. thaliana) were successfully determined. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. One pot synthesis of magnetic graphene/carbon nanotube composites as magnetic dispersive solid-phase extraction adsorbent for rapid determination of oxytetracycline in sewage water.

    Science.gov (United States)

    Sun, Yunyun; Tian, Jing; Wang, Lu; Yan, Hongyuan; Qiao, Fengxia; Qiao, Xiaoqiang

    2015-11-27

    A simple and time-saving one pot synthesis of magnetic graphene/carbon nanotube composites (M-G/CNTs) was developed that could avoid the tedious drying process of graphite oxide, and G/CNTs were modified by Fe3O4 nanoparticles in the reduction procedure. It contributed to a shorten duration of the synthesis process of M-G/CNTs. The obtained M-G/CNTs were characterized and the results indicated that CNTs and Fe3O4 nanoparticles were served as spacer distributing to the layers of graphene, which was beneficial for enlarging surface area and improving extraction efficiency. Moreover, M-G/CNTs showed good magnetic property and outstanding thermal stability. Then M-G/CNTs were applied as adsorbent of magnetic dispersive solid-phase extraction for rapid extraction and determination of oxytetracycline in sewage water. Under the optimum conditions, good linearity was obtained in the range of 20-800ngmL(-1) and the recoveries were ranged from 95.5% to 112.5% with relative standard deviations less than 5.8%. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Dynamic reverse phase transformation induced high-strain-rate superplasticity in low carbon low alloy steels with commercial potential.

    Science.gov (United States)

    Cao, Wenquan; Huang, Chongxiang; Wang, Chang; Dong, Han; Weng, Yuqing

    2017-08-23

    Superplastic materials are capable of exhibiting large tensile elongation at elevated temperature, which is of great industrial significance because it forms the basis of a fabrication method to produce complex shapes. Superplasticity with elongation larger than 500% has been widely realized in many metals and alloys, but seldomly been succeeded in low carbon low alloy steel, even though it is commercially applied in the largest quantity. Here we report ultrahigh superplastic elongation of 900-1200% in the FeMnAl low carbon steels at high strain rate of 10-2-10-3 s-1. Such high-strain-rate superplasticity was attributed to dynamic austenite reverse phase transformation from a heavily cold rolled ferrite to fine-grained ferrite/austenite duplex microstructure and subsequent limited dynamic grain coarsening, under which a large fraction of high angle boundaries can be resulted for superplastic deformation. It is believed that this finding of the low carbon low alloy steel with ultrahigh superplasticity and relative low cost would remarkably promote the application of superplastic forming technique in automobile, aeronautical, astronautical and other fields.

  9. Gas-Phase Reaction Pathways and Rate Coefficients for the Dichlorosilane-Hydrogen and Trichlorosilane-Hydrogen Systems

    Science.gov (United States)

    Dateo, Christopher E.; Walch, Stephen P.

    2002-01-01

    As part of NASA Ames Research Center's Integrated Process Team on Device/Process Modeling and Nanotechnology our goal is to create/contribute to a gas-phase chemical database for use in modeling microelectronics devices. In particular, we use ab initio methods to determine chemical reaction pathways and to evaluate reaction rate coefficients. Our initial studies concern reactions involved in the dichlorosilane-hydrogen (SiCl2H2--H2) and trichlorosilane-hydrogen (SiCl2H-H2) systems. Reactant, saddle point (transition state), and product geometries and their vibrational harmonic frequencies are determined using the complete-active-space self-consistent-field (CASSCF) electronic structure method with the correlation consistent polarized valence double-zeta basis set (cc-pVDZ). Reaction pathways are constructed by following the imaginary frequency mode of the saddle point to both the reactant and product. Accurate energetics are determined using the singles and doubles coupled-cluster method that includes a perturbational estimate of the effects of connected triple excitations (CCSD(T)) extrapolated to the complete basis set limit. Using the data from the electronic structure calculations, reaction rate coefficients are obtained using conventional and variational transition state and RRKM theories.

  10. Rapid rates of aerobic methane oxidation at the feather edge of gas hydrate stability in the waters of Hudson Canyon, US Atlantic Margin

    Science.gov (United States)

    Leonte, Mihai; Kessler, John D.; Kellermann, Matthias Y.; Arrington, Eleanor C.; Valentine, David L.; Sylva, Sean P.

    2017-05-01

    Aerobic oxidation is an important methane sink in seawater overlying gas seeps. Recent surveys have identified active methane seeps in the waters of Hudson Canyon, US Atlantic Margin near the updip limit of methane clathrate hydrate stability. The close proximity of these seeps to the upper stability limit of methane hydrates suggests that changing bottom water temperatures may influence the release rate of methane into the overlying water column. In order to assess the significance of aerobic methane oxidation in limiting the atmospheric expression of methane released from Hudson Canyon, the total extent of methane oxidized along with integrated oxidation rates were quantified. These calculations were performed by combining the measurements of the natural levels of methane concentrations, stable carbon isotopes, and water current velocities into kinetic isotope models yielding rates ranging from 22.8 ± 17 to 116 ± 76 nM/day with an average of 62.7 ± 37 nM/day. Furthermore, an average of 63% of methane released into the water column from an average depth of 515 m was oxidized before leaving this relatively small study area (6.5 km2). Results from the kinetic isotope model were compared to previously-published but concurrently-sampled ex situ measurements of oxidation potential performed using 13C-labeled methane. Ex situ rates were substantially lower, ranging from 0.1 to 22.5 nM/day with an average of 5.6 ± 2.3 nM/day, the discrepancy likely due to the inherent differences between these two techniques. Collectively, the results reveal exceptionally-rapid methane oxidation, with turnover times for methane as low as 0.3-3.7 days, indicating that methane released to the water column is removed quantitatively within the greater extent of Hudson Canyon. The red line represents the original Rayleigh model output, Eq. (1), detailed in the text. The red line represents the original Rayleigh model output, Eq. (1), detailed in the text.

  11. Imaging of vaporised sub-micron phase change contrast agents with high frame rate ultrasound and optics.

    Science.gov (United States)

    Lin, Shengtao; Zhang, Ge; Jamburidze, Akaki; Chee, Melisse; Leow, Chee Hau; Garbin, Valeria; Tang, Meng-Xing

    2018-01-31

    Phase-change ultrasound contrast agent (PCCA), or nanodroplet shows promises as an alternative to conventional microbubble agent over a wide range of diagnostic applications. In the meantime, high-frame-rate (HFR) ultrasound imaging with microbubbles enables unprecedentedly temporal resolution compared to traditional contrast-enhanced ultrasound imaging. The combination of HFR ultrasound imaging and PCCAs can offer opportunities to observe and better understand PCCA behaviour after vaporisation capturing the fast phenomenon at a high temporal resolution. In this study, we utilised HFR ultrasound at frame rates in the kilohertz range (5-20 kHz) to image the native and size-selected PCCA populations immediately after vaporisation in vitro with clinical acoustic parameters. The size-selected PCCAs through filtration are shown to preserve submicron-sized (mean diameter < 200 nm) population without micron-sized outliers (> 1 µm) that are originally from the native PCCA emulsion. The results demonstrate imaging signals with different amplitude and temporal features compared to that of microbubbles. Compared with microbubbles, both B-mode and Pulse-Inversion (PI) signals from vaporised PCCA populations were reduced significantly in the first tens of milliseconds, while only B-mode signals from the PCCAs recovered during the next 400 ms, suggesting significant changes to the size distribution of PCCAs after vaporisation. It is also shown that such recovery in signal over time is not evident when using size-selective PCCAs. Furthermore, it was found that signals from the vaporised PCCA populations are affected by the amplitude and frame rate of the HFR ultrasound imaging. Using high-speed optical camera observation (30 kHz), we observed the particle size change in the vaporised PCCA populations exposed to the HFR ultrasound imaging pulses. These findings can benefit the understandings of PCCA behaviour under HFR ultrasound imaging. © 2018 Institute of Physics and

  12. Comparison of false negative rates and limits of detection following macrofoam-swab sampling of Bacillus anthracis surrogates via Rapid Viability PCR and plate culture.

    Science.gov (United States)

    Hutchison, Janine R; Piepel, Greg F; Amidan, Brett G; Hess, Becky M; Sydor, Michael A; Deatherage Kaiser, Brooke L

    2018-01-21

    We evaluated the effects of Bacillus anthracis surrogates, low surface concentrations, surface materials, and assay methods on false-negative rate (FNR) and limit of detection (LOD 95 ) for recovering Bacillus spores using a macrofoam-swab sampling procedure. Bacillus anthracis Sterne or Bacillus atrophaeus Nakamura spores were deposited over a range of low target concentrations (2 - 500 coupon -1 ) onto glass, stainless steel, vinyl tile, and plastic. Samples were assayed using a modified Rapid Viability-PCR (mRV-PCR) method and the traditional plate culture method to obtain FNR and LOD 95 results. Mean FNRs tended to be lower for mRV-PCR compared to culturing, and increased as spore concentration decreased for all surface materials. Surface material, but not B. anthracis surrogate, influenced FNRs with the mRV-PCR method. The mRV-PCR LOD 95 was lowest for glass and highest for vinyl tile. LOD 95 values overall were lower for mRV-PCR than for the culture method. This study adds to the limited data on FNR and LOD 95 for mRV-PCR and culturing methods with low concentrations of B. anthracis sampled from various surface materials by the CDC macrofoam-swab method. These are key inputs for planning characterization and clearance studies for low contamination levels of B. anthracis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Exploitation of rapid acidification phenomena of food waste in reducing the hydraulic retention time (HRT) of high rate anaerobic digester without conceding on biogas yield.

    Science.gov (United States)

    Kuruti, Kranti; Begum, Sameena; Ahuja, Shruti; Anupoju, Gangagni Rao; Juntupally, Sudharshan; Gandu, Bharath; Ahuja, Devender Kumar

    2017-02-01

    The aim of the present work was to study and infer a full scale experience on co-digestion of 1000kg of FW (400kg cooked food waste and 600kg uncooked food waste) and 2000L of rice gruel (RG) on daily basis based on a high rate biomethanation technology called "Anaerobic gas lift reactor" (AGR). The pH of raw substrate was low (5.2-5.5) that resulted in rapid acidification phenomena with in 12h in the feed preparation tank that facilitated to obtain a lower hydraulic residence time (HRT) of 10days. At full load, AGR was fed with 245kg of total solids, 205kg of volatile solids (167kg of organic matter in terms of chemical oxygen demand) which resulted in the generation of biogas and bio manure of 140m3/day and 110kg/day respectively. The produced biogas replaced 60-70kg of LPG per day. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. On-line solid-phase extraction-short-column liquid chromatography combined with various tandem mass spectrometric scanning strategies for the rapid study of transformation of pesticides in surface water.

    NARCIS (Netherlands)

    Hogenboom, A.C.; Niessen, W.M.A.; Brinkman, U.A.T.

    1999-01-01

    The applicability of solid-phase extraction-short-column liquid chromatography using two short columns (i.e., 10 and 20 mm long) coupled on-line with tandem mass spectrometric detection is demonstrated for the rapid degradation study of pesticides and their transformation products in water at the

  15. Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase

    Directory of Open Access Journals (Sweden)

    Martínez-Valencia María Asunción

    2015-06-01

    Full Text Available Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak, a peak rate of force development (RFDpeak and time to RFD (TRFD in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001 in sprint times (20 and 30 m sprint for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s−1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s−1, p ≤ 0.01. Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

  16. A tool for rapid screening of direct DNA agents using reaction rates and relative interaction potency: towards screening environmental contaminants for hazard.

    Science.gov (United States)

    Gavina, Jennilee M A; Rubab, Mamoona; Zhang, Huijuan; Zhu, Jiping; Nong, Andy; Feng, Yong-Lai

    2011-11-01

    DNA damage represents a potential biomarker for determining the exposure risk to chemicals and may provide early warning data for identifying chemical hazards to human health. Here, we have demonstrated a simple chromatography-based method that can be used to rapidly screen for the presence of chemical hazards as well as to determine parameters relevant to hazard assessment. In this proof-of-principle study, a simple in vitro system was used to determine the interaction of pollutants and probable carcinogens, phenyl glycidyl ether (PGE), tetrachlorohydroquinone (Cl(4)HQ), methylmethane sulfonate (MMS), styrene-7,8-oxide (SO), and benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), a metabolite of benzo[a]pyrene (B[a]P), with single- and double-stranded DNA probes. Differences in potency and reaction kinetics were studied for chemical and DNA type. A relative interaction potency equivalency (PEQ) of a chemical was determined by ratio of interaction potency of a chemical to BPDE as the reference chemical in the reaction with single- and double-stranded oligodeoxynucleotides. PEQs were found to be BPDE > PGE > SO > MMS > Cl(4)HQ for single-stranded oligodeoxynucleotides while they were found to be BPDE > PGE > Cl(4)HQ > MMS > SO for double-stranded oligodeoxynucleotides. Kinetics evaluation revealed that BPDE reacted with both DNA probes at a significantly faster rate, as compared to the remaining test chemicals. Equilibrium was reached within an hour for BPDE, but required a minimum of 48 h for the remaining chemicals. First-order rate constants were (1.61 ± 0.2) × 10(-3) s(-1) and (3.18 ± 0.4) × 10(-4) s(-1) for reaction of BPDE with double- and single-stranded DNA, respectively. The remaining chemicals possessed rate constants from 2 to 13 × 10(-6) s(-1) with a relative kinetic order for reaction with DNA of BPDE ≫ MMS > SO > PGE > Cl(4)HQ for ds-DNA and BPDE ≫ SO ≈ Cl(4)HQ ≈ MMS > PGE for ss-DNA. We further found that the reaction potency, defined by

  17. A semi-empirical model for the complete orientation dependence of the growth rate for vapor phase epitaxy - Chloride VPE of GaAs

    Science.gov (United States)

    Seidel-Salinas, L. K.; Jones, S. H.; Duva, J. M.

    1992-01-01

    A semi-empirical model has been developed to determine the complete crystallographic orientation dependence of the growth rate for vapor phase epitaxy (VPE). Previous researchers have been able to determine this dependence for a limited range of orientations; however, our model yields relative growth rate information for any orientation. This model for diamond and zincblende structure materials is based on experimental growth rate data, gas phase diffusion, and surface reactions. Data for GaAs chloride VPE is used to illustrate the model. The resulting growth rate polar diagrams are used in conjunction with Wulff constructions to simulate epitaxial layer shapes as grown on patterned substrates. In general, this model can be applied to a variety of materials and vapor phase epitaxy systems.

  18. Preconcentration and sensitive determination of hexabromocyclododecane diastereomers in environmental water samples using solid phase extraction with bamboo charcoal cartridge prior to rapid resolution liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Zhao, Ru-Song; Hu, Cong; Zhou, Jia-Bin; Yuan, Jin-Peng; Wang, Shan-Shan; Wang, Xia

    2011-05-01

    In this paper, a simple and cheap method for the simultaneous preconcentration and sensitive determination of three hexabromocyclododecane (HBCD) diastereomers (α-, β-, and γ-HBCD) in environmental water samples has been developed. It was based on solid phase extraction (SPE) and rapid resolution liquid chromatography-electrospray tandem mass spectrometry. Bamboo charcoal, one kind of cheap material, was investigated and used as SPE adsorbent for the enrichment and determination of HBCD diastereomers. Related important parameters affecting extraction efficiencies, including type and volume of eluant, amount of sorbent, sample pH, flow rate, and sample volume, were investigated and optimized in detail. Under the optimum conditions, experimental data exhibited excellent linear relationships between peak area and concentrations over the range 0.1-10 μg L(-1). The limits of detection and precision were in the range of 0.005-0.015 μg L(-1) and 4.59-7.47%, respectively. The proposed method has been successfully applied for the trace analysis of HBCD diastereomers in real-world environmental water samples.

  19. Rapid in vivo determination of fluoroquinolones in cultured puffer fish (Takifugu obscurus) muscle by solid-phase microextraction coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Tang, Yijia; Xu, Jianqiao; Chen, Le; Qiu, Junlang; Liu, Yuan; Ouyang, Gangfeng

    2017-12-01

    Fluoroquinolones (FQs) are a group of antimicrobial agents that have been widely used for therapeutic purposes in clinical medicine for human and veterinary diseases, as well as in aquaculture production. Their residues, however, may survive in foods of animal origin, thus causing health risks for human. In this study, a rapid and sensitive method based on in vivo solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to detect the residues of five FQs in cultured puffer fish (Takifugu obscurus). In vitro fiber evaluation experiment demonstrated that, compared with the thicker polydimethylsiloxane (PDMS) coating (165µm), the custom-made biocompatible C18-PAN fibers (45µm) exhibited much higher extraction efficiencies towards FQs (approximately 9-31 times). The custom-made C18-PAN coating also possessed excellent reproducibility in fish muscle with the intra-fiber relative standard deviations (RSDs) ranging from 11.2% to 14.3% (n = 6) and inter-fiber RSDs ranging from 13.1% to 16.1% (n = 6), which was suitable for in vivo sampling. The custom-made SPME fibers were subsequently applied to determine fluoroquinolones in dorsal-epaxial muscle of living puffer fish. The accuracies were verified through the comparison with traditional liquid extraction (LE) method, and the sensitivities were demonstrated to be satisfying with the limits of detection (LODs) ranging from 0.3ngg -1 to 1.5ngg -1 . In general, this study presented a convenient and high-efficient method to determine fluoroquinolones in puffer fish by in vivo sampling. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Rapid in vivo determination of tetrodotoxin in pufferfish (Fugu) muscle by solid-phase microextraction coupled to high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Chen, Le; Qiu, Junlang; Tang, Yijia; Xu, Jianqiao; Huang, Shuyao; Liu, Yuan; Ouyang, Gangfeng

    2017-08-15

    Tetrodotoxin (TTX) is one of the most toxic substances of non-protein in nature. In present study, a rapid and sensitive method based on in vivo solid-phase microextraction (SPME) coupled to liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed to detect the endogenous TTX in pufferfish (Fugu). Fiber evaluation experiments demonstrated that, compared with the commercial PDMS and PA fibers, the home-made electrospun PS@PDA-GA fibers exhibited much better extraction performance towards to TTX in water (120 times and 20 times, respectively), under the optimized conditions. Then, the home-made SPME fibers were employed to extract TTX in spiked homogeneous fish muscle samples, and a LC-MS-MS was used for the analysis. The reproducibilities (RSDs of inter and intra fiber were 12.1%, and 7.9% respectively), linear range (10-1000ngg-1, R2=0.9963) and sensitivity (the LOD was 2.3ngg-1) of the method were found to be excellent and satisfactory for further in vivo experiments. Especially the LOD of the established method is lower than the National Standard Method of China (GB/T 23217-2008, LOD 50ngg-1). Subsequently, the method was successfully applied to detect the TTX in the dorsal muscle of living pufferfish, and the accuracy was verified with traditional liquid extraction (LE) method. In general, this is the first study to detect TTX in pufferfish by in vivo sampling method, which provided a promising alternative method for the studies of TTX, and also advanced the implementation of SPME for more in vivo studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. An Effective Continuum Model for the Liquid-to-Gas Phase Change in a Porous Medium Driven by Solute Diffusion: I. Constant Pressure Decline Rates

    Energy Technology Data Exchange (ETDEWEB)

    Tsimpanogiannis, Ioannis N.; Yortsos, Yanis C.

    2001-08-15

    This report, focuses on the isothermal gas phase growth from a supersaturated, slightly compressible, binary liquid in a porous medium. This is driven by mass transfer, the extent of which is controlled by the application of either a constant-rate decline of the system pressure or the withdrawal of the liquid at a constant rate. This report deals with the first process. Pressure depletion due to constant-rate liquid withdrawal is analyzed in a companion report .

  2. Nephrotic range proteinuria as a strong risk factor for rapid renal function decline during pre-dialysis phase in type 2 diabetic patients with severely impaired renal function.

    Science.gov (United States)

    Kitai, Yuichiro; Doi, Yohei; Osaki, Keisuke; Sugioka, Sayaka; Koshikawa, Masao; Sugawara, Akira

    2015-12-01

    Proteinuria is an established risk factor for progression of renal disease, including diabetic nephropathy. The predictive power of proteinuria, especially nephrotic range proteinuria, for progressive renal deterioration has been well demonstrated in diabetic patients with normal to relatively preserved renal function. However, little is known about the relationship between severity of proteinuria and renal outcome in pre-dialysis diabetic patients with severely impaired renal function. 125 incident dialysis patients with type 2 diabetes were identified. This study was aimed at retrospectively evaluating the impact of nephrotic range proteinuria (urinary protein-creatinine ratio above 3.5 g/gCr) on renal function decline during the 3 months just prior to dialysis initiation. In total, 103 patients (82.4 %) had nephrotic range proteinuria. The median rate of decline in estimated glomerular filtration rate (eGFR) in this study population was 0.98 (interquartile range 0.51-1.46) ml/min/1.73 m(2) per month. Compared to patients without nephrotic range proteinuria, patients with nephrotic range proteinuria showed significantly faster renal function decline (0.46 [0.24-1.25] versus 1.07 [0.64-1.54] ml/min/1.73 m(2) per month; p = 0.007). After adjusting for gender, age, systolic blood pressure, serum albumin, calcium-phosphorus product, hemoglobin A1c, and use of an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker, patients with nephrotic range proteinuria showed a 3.89-fold (95 % CI 1.08-14.5) increased risk for rapid renal function decline defined as a decline in eGFR ≥0.5 ml/min/1.73 m(2) per month. Nephrotic range proteinuria is the predominant renal risk factor in type 2 diabetic patients with severely impaired renal function receiving pre-dialysis care.

  3. Phase-rectified signal averaging for intrapartum electronic fetal heart rate monitoring is related to acidaemia at birth.

    Science.gov (United States)

    Georgieva, A; Papageorghiou, A T; Payne, S J; Moulden, M; Redman, C W G

    2014-06-01

    Recent studies suggest that phase-rectified signal averaging (PRSA), measured in antepartum fetal heart rate (FHR) traces, may sensitively indicate fetal status; however, its value has not been assessed during labour. We determined whether PRSA relates to acidaemia in labour, and compare its performance to short-term variation (STV), a related computerised FHR feature. Historical cohort. Large UK teaching hospital. All 7568 Oxford deliveries that met the study criteria from April 1993 to February 2008. We analysed the last 30 minutes of the FHR and associated outcomes of infants. We used computerised analysis to calculate PRSA decelerative capacity (DC(PRSA)), and its ability to predict umbilical arterial blood pH ≤ 7.05 using receiver operator characteristic (ROC) curves and event rate estimates (EveREst). We compared DC(PRSA) with STV calculated on the same traces. Umbilical arterial blood pH ≤ 7.05. We found that PRSA could be measured in all cases. DC(PRSA) predicted acidaemia significantly better than STV: the area under the ROC curve was 0.665 (95% CI 0.632-0.699) for DC(PRSA), and 0.606 (0.573-0.639) for STV (P = 0.007). EveREst plots showed that in the worst fifth centile of cases, the incidence of low pH was 17.75% for DC(PRSA) but 11.00% for STV (P < 0.001). DC(PRSA) was not highly correlated with STV. DC(PRSA) of the FHR can be measured in labour, and appears to predict acidaemia more accurately than STV. Further prospective evaluation is warranted to assess whether this could be clinically useful. The weak correlation between DC(PRSA) and STV suggests that they could be combined in multivariate FHR analyses. © 2014 Royal College of Obstetricians and Gynaecologists.

  4. Magnetic resonance measurement of blood and CSF flow rates with phase contrast--normal values, repeatability and CO2 reactivity.

    Science.gov (United States)

    Piechnik, Stefan K; Summers, Paul E; Jezzard, Peter; Byrne, James V

    2008-01-01

    Similarity in flow pulsatility has been proposed as a basis for semi-automated segmentation of vessel lumens for MR-based flow measurement, but re-examinations of salient aspects of the methodology have not been widely reported. 12 normal control subjects underwent repeated (3*Baseline+1*5%CO2) phase contrast measurements of CSF flow through the cerebral aqueduct and foramen magnum, and CBF through the 6 large cranial vessels at the level of the 1st vertebra. Average flows were calculated for regions temporally correlated (0.3 < or = Rthreshold < or = 0.95) to user defined seed points and their 3 x 3 neighbours. Arterial CBF averaged 710ml/min, with low variability (+/- 4%/17%, intra-individual/group CV respectively) and was the only flow to respond significantly to 5%/mmHg CO2. Venous outflow was much smaller (298ml/min +/- 10%/ 72%), possibly due to the weak venous pulse and variable venous anatomy. Average CSF flows exceeded the classical 0.4ml/min CSF production rate and were highly variable--aqueduct: 0.6ml/min (+/- 50%/93%), foramen magnum: -2.7ml/min (+/- 158%/226%). This preliminary analysis identified procedural steps that can improve the accuracy and repeatability of MR flow measurements, but the process remains user-dependent for the weakly pulsatile foramen magnum CSF and venous flows where variability remains a significant confound even to relatively large perturbations such as CO2 administration.

  5. Local anti-correlation between star-formation rate and gas-phase metallicity in disk galaxies

    Science.gov (United States)

    Sánchez Almeida, J.; Caon, N.; Muñoz-Tuñón, C.; Filho, M.; Cerviño, M.

    2018-02-01

    Using a representative sample of 14 star-forming dwarf galaxies in the local Universe, we show the existence of a spaxel-to-spaxel anti-correlation between the index N2 ≡ log ([NII]λ6583/Hα) and the Hα flux. These two quantities are commonly employed as proxies for gas-phase metallicity and star formation rate (SFR), respectively. Thus, the observed N2 to Hα relation may reflect the existence of an anti-correlation between the metallicity of the gas forming stars and the SFR it induces. Such an anti-correlation is to be expected if variable external metal-poor gas fuels the star-formation process. Alternatively, it can result from the contamination of the star-forming gas by stellar winds and SNe, provided that intense outflows drive most of the metals out of the star-forming regions. We also explore the possibility that the observed anti-correlation is due to variations in the physical conditions of the emitting gas, other than metallicity. Using alternative methods to compute metallicity, as well as previous observations of HII regions and photoionization models, we conclude that this possibility is unlikely. The radial gradient of metallicity characterizing disk galaxies does not produce the correlation either.

  6. Correlation between regular mouthing movements and heart rate patterns during non-rapid eye movement periods in normal human fetuses between 32 and 40 weeks of gestation.

    Science.gov (United States)

    Otera, Yuka; Morokuma, Seiichi; Fukushima, Kotaro; Wake, Norio; Kato, Kiyoko

    2013-06-01

    Regular mouthing movements (RMMs) are observed during fetal non-rapid eye movement (NREM) periods. To determine the correlation between RMM and fetal heart rate (FHR) patterns during NREM periods. Fetal eye and mouth movements and FHR patterns were observed and recorded. 50 normal singleton pregnancies between 32 and 40 weeks of gestation. Changes in the power spectrum ratio of 3-minute blocks of RMM clusters, FHR with RMM clusters (HR+), and FHR without RMM clusters (HR-) were calculated at a frequency band of 0.02 Hz among 3 gestational age groups: group 1, 32-34 weeks gestation; group 2, 35-37 weeks gestation; group 3, 38-40 weeks gestation. We calculated the percentage of cases showing dominant peak ratios of RMM and HR+ in the same frequency band, the maximum correlation coefficient, and its lag time. In group 3, the dominant peaks of both RM and HR+ were present at the same frequency band, 0.06-0.08 Hz; this was not seen in the other groups' relative power spectral patterns. The percentage of cases showing dominant peaks of RMM and HR+ in the same frequency band increased with advancing gestational age. The maximum correlation coefficient in groups 1 (0.28 ± 0.11) and 3 (0.45 ± 0.14) differed significantly (p<0.05). The correlation between RMM and FHR patterns became stronger, and their rhythmicity was similar, from 38 to 40 gestational weeks, suggesting that a common center starts to govern both patterns at approximately 38 weeks gestation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. High-Dose-Rate Brachytherapy as a Monotherapy for Favorable-Risk Prostate Cancer: A Phase II Trial

    Energy Technology Data Exchange (ETDEWEB)

    Barkati, Maroie [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Williams, Scott G., E-mail: scott.williams@petermac.org [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia); Foroudi, Farshad; Tai, Keen Hun; Chander, Sarat [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia); Dyk, Sylvia van [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); See, Andrew [Ballarat Austin Radiation Oncology Centre, Ballarat (Australia); Duchesne, Gillian M. [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia)

    2012-04-01

    Purpose: There are multiple treatment options for favorable-risk prostate cancer. High-dose-rate (HDR) brachytherapy as a monotherapy is appealing, but its use is still investigational. A Phase II trial was undertaken to explore the value of such treatment in low-to-intermediate risk prostate cancer. Methods and Materials: This was a single-institution, prospective study. Eligible patients had low-risk prostate cancer features but also Gleason scores of 7 (51% of patients) and stage T2b to T2c cancer. Treatment with HDR brachytherapy with a single implant was administered over 2 days. One of four fractionation schedules was used in a dose escalation study design: 3 fractions of 10, 10.5, 11, or 11.5 Gy. Patients were assessed with the Common Terminology Criteria for Adverse Events version 2.0 for urinary toxicity, the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scoring schema for rectal toxicity, and the Expanded Prostate Cancer Index Composite (EPIC) questionnaire to measure patient-reported health-related quality of life. Biochemical failure was defined as a prostate-specific antigen (PSA) nadir plus 2 ng/ml. Results: Between 2003 and 2008, 79 patients were enrolled. With a median follow-up of 39.5 months, biochemical relapse occurred in 7 patients. Three- and 5-year actuarial biochemical control rates were 88.4% (95% confidence interval [CI], 78.0-96.2%) and 85.1% (95% CI, 72.5-94.5%), respectively. Acute grade 3 urinary toxicity was seen in only 1 patient. There was no instance of acute grade 3 rectal toxicity. Rates of late grade 3 rectal toxicity, dysuria, hematuria, urinary retention, and urinary incontinence were 0%, 10.3%, 1.3%, 9.0%, and 0%, respectively. No grade 4 or greater toxicity was recorded. Among the four (urinary, bowel, sexual, and hormonal) domains assessed with the EPIC questionnaire, only the sexual domain did not recover with time. Conclusions: HDR brachytherapy as a monotherapy for favorable

  8. The Effect of Submicron Second-Phase Particles on the Rate of Grain Refinement in a Copper-Oxygen Alloy During Cold Spray

    Science.gov (United States)

    Zhang, Yinyin; Brodusch, Nicolas; Descartes, Sylvie; Shockley, J. Michael; Gauvin, Raynald; Chromik, Richard R.

    2017-10-01

    The effect of non-deformable submicron second-phase particles ( d = 200-500 nm) on microstructural refinement during cold spray was examined. Using single particle impact testing, two types of splats were fabricated using two different feedstocks: a Cu-0.21wt.%O powder containing Cu2O second-phase particles and a single-phase Cu. Microstructural evolution analysis using high-resolution electron backscatter diffraction shows grain refinement occurred at a higher rate in the Cu-0.21wt.%O powder. That was due to dynamic recrystallization initiated by particle-stimulated nucleation (PSN). High-strain-rate deformation of cold spray was found to be the key to activate PSN. The present study suggests cold spray is a possible technique to fabricate ultrafine-grained materials by using feedstock containing second-phase particles.

  9. Rate of force development

    DEFF Research Database (Denmark)

    Maffiuletti, Nicola A; Aagaard, Per; Blazevich, Anthony J

    2016-01-01

    The evaluation of rate of force development during rapid contractions has recently become quite popular for characterising explosive strength of athletes, elderly individuals and patients. The main aims of this narrative review are to describe the neuromuscular determinants of rate of force...... development and to discuss various methodological considerations inherent to its evaluation for research and clinical purposes. Rate of force development (1) seems to be mainly determined by the capacity to produce maximal voluntary activation in the early phase of an explosive contraction (first 50-75 ms......), particularly as a result of increased motor unit discharge rate; (2) can be improved by both explosive-type and heavy-resistance strength training in different subject populations, mainly through an improvement in rapid muscle activation; (3) is quite difficult to evaluate in a valid and reliable way...

  10. Rapid and Green Separation of Mono- and Diesters of Monochloropropanediols by Ultrahigh Performance Supercritical Fluid Chromatography-Mass Spectrometry Using Neat Carbon Dioxide as a Mobile Phase.

    Science.gov (United States)

    Jumaah, Firas; Jędrkiewicz, Renata; Gromadzka, Justyna; Namieśnik, Jacek; Essén, Sofia; Turner, Charlotta; Sandahl, Margareta

    2017-09-20

    This study demonstrates the effect of column selectivity and density of supercritical carbon dioxide (SC-CO 2 ) on the separation of monochloropropanediol (MCPD) esters, known as food toxicants, using SC-CO 2 without addition of cosolvent in ultrahigh performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS). This study shows that over 20 2-monochloropropanediol (2-MCPD) and 3-monochloropropanediol (3-MCPD) mono- and diesters are separated on a 2-picolylamine column in less than 12 min. The presence and position of a hydroxyl group in the structure, the number of unsaturated bonds, and the acyl chain length play a significant role in the separation of MCPD esters. The flow rate, backpressure, and column oven temperature, which affect the density of the mobile phase, were shown to have a substantial impact on retention, efficiency, and selectivity. The developed method was successfully applied for the determination of MCPD esters in refined oils and showed a close to excellent green analysis score using the Analytical Eco-Scale.

  11. Effect of Five-Finger Shoes on Vertical Ground Reaction Force Loading Rates and Perceived Comfort during the Stance Phase of the Running

    OpenAIRE

    Seyede Zeynab Hoseini; Mansor Eslami

    2016-01-01

    Objective:  Increased vertical ground reaction force loading rates and lack of comfort footwear in the early stance phase can increase the risk of overuse injuries. The purpose of this study was to investigate the effect of Five-finger shoes on vertical ground reaction force loading rate and perceived comfort during the stance phase of running. Methods: 15 male students (aged 24 ± 5/24 years, weight 75/8 ± 4/61 kg, height 178/6 ± 6/64 cm) were selected. Subjects ...

  12. Interaction of rare gas metastable atoms. [Differential and total cross sections, elastic scattering, ionization, potential scattering, phase shifts, rate constants

    Energy Technology Data Exchange (ETDEWEB)

    Wang, A.Z.F.

    1977-11-01

    The physical and chemical properties of metastable rare gas atoms are discussed and summarized. This is followed by a detailed examination of the various possible pathways whereby the metastable's excess electronic energy can be dissipated. The phenomenon of chemi-ionization is given special emphasis, and a theoretical treatment based on the use of complex (optical) potential is presented. This is followed by a discussion on the unique advantages offered by elastic differential cross section measurements in the apprehension of the fundamental forces governing the ionization process. The methodology generally adopted to extract information about the interaction potential for scattering data is also systematically outlined. Two widely studied chemi-ionization systems are then closely examined in the light of accurate differential cross section measurements obtained in this work. The first system is He(2/sup 3/S) + Ar for which one can obtain an interaction potential which is in good harmony with the experimental results of other investigators. The validity of using the first-order semiclassical approximation for the phase shifts calculation in the presence of significant opacities is also discussed. The second reaction studied is He*+D/sub 2/ for which measurements were made on both spin states of the metastable helium. A self-consistent interaction potential is obtained for the triplet system, and reasons are given for not being able to do likewise for the singlet system. The anomalous hump proposed by a number of laboratories is analyzed. Total elastic and ionization cross sections as well as rate constants are calculated for the triplet case. Good agreement with experimental data is found. Finally, the construction and operation of a high power repetitively pulsed nitrogen laser pumped dye laser system is described in great details. Details for the construction and operation of a flashlamp pumped dye laser are likewise given.

  13. Effects of Organic Loading Rate on the Performance of a Pressurized Anaerobic Filter in Two-Phase Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Yuling Chen

    2014-02-01

    Full Text Available The effect of organic loading rate (OLR on a pressurized anaerobic filter was studied in a laboratory two-phase anaerobic digestion system. The anaerobic filter was operated successively at two working pressures (9 bar and 1.5 bar. The OLR(COD for each pressure was increased from 5 to 17.5 kg·m−3·day−1. The best performance of the reactor at 9 bar was observed at OLR(COD of 12.5 kg·m−3·day−1 and hydraulic retention time (HRT of 1.8 day, with specific biogas productivity (SBP of 5.3 L·L−1·day−1 and COD degradation grade of 90.6%. At higher OLRs and shorter HRTs, the process became unstable. In contrast, there was no indication of digester failure during the experiments at 1.5 bar. The SBP peaked at OLR(COD of 17.5 kg·m−3·day−1 with 8.2 L·L−1·day−1, where COD degradation grade was 90.4%. The biogas collected from the reactor at 9 bar and 1.5 bar contained approximately 74.5% CH4 and 66.2% CH4, respectively, regardless of OLR variation. At OLR(COD of 5–12.5 kg·m−3·day−1, the reactor at 9 bar had the same specific methane yield as at 1.5 bar, which was in the range of 0.31–0.32 LN·g−1COD. Raising the working pressure in the reactor resulted in an increase of methane content of the produced biogas. However, the low pH value (approximately 6.5 inside the reactor, induced by high CO2 partial pressure seemed to limit the reactor performance at high OLRs and short HRT.

  14. Effect of temperature, water-phase salt and phenolic contents on Listeria monocytogenes growth rates on cold-smoked salmon and evaluation of secondary models

    OpenAIRE

    Cornu, M; Beaufort, A.; Rudelle, S.; Laloux, L.; Bergis, H; Miconnet, N; Serot, T.; Delignette-Muller, M. L.

    2006-01-01

    Salting and smoking are ancient processes for fish preservation. The effects of salt and phenolic smoke compounds on the growth rate of L. monocytogenes in cold-smoked salmon were investigated through physico-chemical analyses, challenge tests on surface of cold-smoked salmon at 4 degrees C and 8 degrees C, and a survey of the literature. Estimated growth rates were compared to predictions of existing secondary models, taking into account the effects of temperature, water phase salt content, ...

  15. Simulation of polymer crystallization induced by temperature using the phase field method: Focus on the Avrami rate constant

    Science.gov (United States)

    Gong, Yang Hao; Detrez, Fabrice; Luo, Yun Mei; Chevalier, Luc

    2017-10-01

    The phase field method has become more important and common as a technique to simulate microstructure evolution at mesoscale in present-day. In this paper, we are interested to model the evolution of isothermal crystallization at mesocopic scale by using the phase field method. The classical method is extended to multiphase field problems in order to describe the junction of spherulites: each phase is identified with an individual phase field and the transformation between all pairs of phases is treated with its own characteristics. The kinetic coefficient M(T) of the phase field model is adjusted in order to reproduce the experimental spherolitic evolution of the crystalline phase, and the crystallization kinetic (k = λ-n, where n is the Avrami exponent) of PET obtained from simulation at different temperature is in good agreement with the experimental data [1,2,3]. The simulation was implemented using the FEM with an explicit time scheme and a null flux as boundary conditions. We then focus on the influence of initial conditions by modeling the dispersion of position and size of the seed. This influence, for a given temperature, emerges from the result of a Monte Carlo simulation with initial random position and size of the seed. Results are discussed.

  16. White ash (Fraxinus americana) health in the Allegheny plateau region, Pennsylvania: Evaluating the relationship between FIA phase 3 crown variables and a categorical rating system

    Science.gov (United States)

    Alejandro A. Royo; Kathleen S. Knight; Jamie M. Himes; Ashley N. Will

    2012-01-01

    Following the detection of white ash (Fraxinus americana) decline in the Allegheny National Forest (ANF) of Pennsylvania, we established an intensified white ash monitoring network throughout the ANF. We rated crowns using both a categorical system as well as Forest Inventory and Analyses (FIA) Phase 3 measures of uncompacted live crown ratio,...

  17. First- and second-order phase transitions between quantum and classical regimes for the escape rate of a biaxial spin system

    CERN Document Server

    Kim, G H

    1999-01-01

    The particle Hamiltonian for a biaxial spin system with a transverse or longitudinal magnetic field is investigated. We apply the Hamiltonian to the quantum-classical escape rate transition in small magnets. It is found that the phase boundary separating the first- and second-order transition is greatly influenced by the transverse anisotropy constant as well as the external magnetic field.

  18. Effect of Acidified Sorbate Solutions on the Lag-Phase Durations and Growth Rates of Listeria monocytogenes on Meat Surfaces.

    Science.gov (United States)

    Hwang, Cheng-An; Huang, Lihan; Juneja, Vijay

    2015-06-01

    The surfaces of ready-to-eat meats are susceptible to postprocessing contamination by Listeria monocytogenes. This study quantified the lag-phase durations (LPD) and growth rates (GR) of L. monocytogenes on the surfaces of cooked ham as affected by sorbate solutions of different concentrations and pH levels. Slices of cooked ham inoculated with a four-strain mixture of L. monocytogenes (ca. 10(3) CFU/g) were surface treated with sorbate solutions of 0 to 4% (wt/vol) at pH 4.0 to 6.5, vacuum packaged, and stored at 4 to 12 °C for up to 45 days. The LPD and GR of L. monocytogenes were used to develop response surface models. The models estimated that the LPD of L. monocytogenes in samples treated with solutions of pH 4.0 to 5.5 (no sorbate) were 0 to 11 days and the GR were 0.25 to 0.36 log CFU/day, respectively, at 4 °C. With the treatments of 2 and 4% (wt/vol) sorbate solutions, the LPD were estimated to be extended to 2 to 26 days and 34 to >45 days, and the GR were reduced to 0.15 to 0.30 and 0 to 0.19 log CFU/day, respectively. At 4 °C, increasing sorbate concentrations by 1% (wt/vol) to 2, 3, and 4% (wt/vol) at pH 5.5 to 4.0 led to an extension of LPD by 2 to 11, 10 to 19, and 18 to 27 days, whereas the GR were reduced by 0.037 to 0.055, 0.048 to 0.066, and 0.060 to 0.078 log CFU/day, respectively. Sorbate also extended the LPD and reduced the GR of L. monocytogenes at 8 and 12 °C. Results indicated that sorbate concentration and pH level were significant factors affecting the LPD and GR of L. monocytogenes and that the combination of sorbate and low pH has potential for use as a surface treatment to control L. monocytogenes on meat surfaces.

  19. Solid-phase PCR for rapid multiplex detection of Salmonella spp. at the subspecies level, with amplification efficiency comparable to conventional PCR

    DEFF Research Database (Denmark)

    Chin, Wai Hoe; Sun, Yi; Høgberg, Jonas

    2017-01-01

    Solid-phase PCR (SP-PCR) has attracted considerable interest in different research fields since it allows parallel DNA amplification on the surface of a solid substrate. However, the applications of SP-PCR have been hampered by the low efficiency of the solid-phase amplification. In order...

  20. Rapid insight into heating-induced phase transformations in the solid state of the calcium salt of atorvastatin using multivariate data analysis

    DEFF Research Database (Denmark)

    Christensen, Niels Peter Aae; Van Eerdenbrugh, Bernard; Kwok, Kaho

    2013-01-01

    To investigate the heating-induced dehydration and melting behavior of the trihydrate phase of the calcium salt of atorvastatin.......To investigate the heating-induced dehydration and melting behavior of the trihydrate phase of the calcium salt of atorvastatin....

  1. A rapid and validated HPLC method to quantify sphingosine 1-phosphate in human plasma using solid-phase extraction followed by derivatization with fluorescence detection

    NARCIS (Netherlands)

    Butter, Jan J.; Koopmans, Richard P.; Michel, Martin C.

    2005-01-01

    We describe the development and validation of analytical methodology for the determination of sphingosine 1-phosphate (S1P) in plasma. It uses solid-phase extraction (SPE) followed by an automated reversed-phase gradient HPLC column-switching system with a pre-column derivatization with

  2. A Simulation Analysis of Errors in the Measurement of Standard Electrochemical Rate Constants from Phase-Selective Impedance Data.

    Science.gov (United States)

    1987-09-30

    systems the ksob is predicted to approach and possibly surpass the maximum values amenable to experimental evaluation, even when using rapid...simulated impedance data were then used to obtain "apparent" values of kSob k(app), using the conventional analysis involving the frequency-dependence

  3. Rapid vaporization of kidney stones, ex vivo, using a Thulium fiber laser at pulse rates up to 500 Hz with a stone basket

    Science.gov (United States)

    Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

    2014-03-01

    The Holmium:YAG laser (λ = 2120 nm) is currently the preferred laser for fragmenting kidney stones in the clinic. However, this laser has some limitations, including operation at low pulse rates and a multimode spatial beam profile which prohibits its use with smaller, more flexible optical fibers. Our laboratory is studying the Thulium fiber laser (λ = 1908 nm) as an alternative lithotripter. The TFL has several advantages, including lower stone ablation thresholds, use with smaller and more flexible fibers, and operation at arbitrary pulse lengths and pulse rates. Previous studies have reported increased stone ablation rates with TFL operation at higher pulse rates, however, stone retropulsion remains an obstacle to even more efficient stone ablation. This study explores TFL operation at high pulse rates in combination with a stone stabilization device (e.g. stone basket) for improved efficiency. A TFL beam with pulse energy of 35 mJ, pulse duration of 500-μs, and pulse rates of 10-500 Hz was coupled into 100-μm-core, low-OH, silica fibers, in contact mode with uric acid and calcium oxalate monohydrate stones, ex vivo. TFL operation at 500 Hz produced UA and COM stone ablation rates up to 5.0 mg/s and 1.3 mg/s, respectively. High TFL pulse rates produced increased stone ablation rates sufficient for use in the clinic.

  4. Liquid-Phase Heat-Release Rates of the Systems Hydrazine-Nitric Acid and Unsymmetrical Dimethylhydrazine-Nitric Acid

    Science.gov (United States)

    Somogyi, Dezso; Feiler, Charles E.

    1960-01-01

    The initial rates of heat release produced by the reactions of hydrazine and unsymmetrical dimethylhydrazine with nitric acid were determined in a bomb calorimeter under conditions of forced mixing. Fuel-oxidant weight ratio and injection velocity were varied. The rate of heat release apparently depended on the interfacial area between the propellants. Above a narrow range of injection velocities representing a critical amount of interfacial area, the rates reached a maximum and were almost constant with injection velocity. The maximum rate for hydrazine was about 70 percent greater than that for unsymmetrical dimethylhydrazine. The total heat released did not vary with mixture ratio over the range studied.

  5. Effect of Five-Finger Shoes on Vertical Ground Reaction Force Loading Rates and Perceived Comfort during the Stance Phase of the Running

    Directory of Open Access Journals (Sweden)

    Seyede Zeynab Hoseini

    2016-06-01

    Full Text Available Objective:  Increased vertical ground reaction force loading rates and lack of comfort footwear in the early stance phase can increase the risk of overuse injuries. The purpose of this study was to investigate the effect of Five-finger shoes on vertical ground reaction force loading rate and perceived comfort during the stance phase of running. Methods: 15 male students (aged 24 ± 5/24 years, weight 75/8 ± 4/61 kg, height 178/6 ± 6/64 cm were selected. Subjects were asked to run over a force plate, in control shoe, five finger shoe and barefoot conditions. Loading rate using the slope of the vertical reaction force and perceived comfort were determined using a visual analogue scale. One factor repeated measures ANOVA was used to test the loading rate hypothesis and Paired t-tests was used to test the meaningfulness of perceived comfort (P<0/05. Results: The effect of shoes on loading rate was found to be not significant (P=0.1. However, comfort of control shoes increased by 10. 92% as compared to that of five-finger shoes (P=0.001.  Conclusion: The loading rate of five-finger shoes is the same as that of barefoot during running; however, as subjects did not perceive them as comfortable as regular shoes are five-finger shoes cannot be advised as a desirable choice in exercises.

  6. Rapid determination of the volatile components in tobacco by ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Yang, Yanqin; Chu, Guohai; Zhou, Guojun; Jiang, Jian; Yuan, Kailong; Pan, Yuanjiang; Song, Zhiyu; Li, Zuguang; Xia, Qian; Lu, Xinbo; Xiao, Weiqiang

    2016-03-01

    An ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction was first employed to determine the volatile components in tobacco samples. The method combined the advantages of ultrasound, microwave, and headspace solid-phase microextraction. The extraction, separation, and enrichment were performed in a single step, which could greatly simplify the operation and reduce the whole pretreatment time. In the developed method, several experimental parameters, such as fiber type, ultrasound power, and irradiation time, were optimized to improve sampling efficiency. Under the optimal conditions, there were 37, 36, 34, and 36 components identified in tobacco from Guizhou, Hunan, Yunnan, and Zimbabwe, respectively, including esters, heterocycles, alkanes, ketones, terpenoids, acids, phenols, and alcohols. The compound types were roughly the same while the contents were varied from different origins due to the disparity of their growing conditions, such as soil, water, and climate. In addition, the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method was compared with the microwave-assisted extraction coupled to headspace solid-phase microextraction and headspace solid-phase microextraction methods. More types of volatile components were obtained by using the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method, moreover, the contents were high. The results indicated that the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction technique was a simple, time-saving and highly efficient approach, which was especially suitable for analysis of the volatile components in tobacco. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. A dilatometric study of the phase transformations in 300 and 350 maraging steels during continuous heating rates

    Directory of Open Access Journals (Sweden)

    Leandro Gomes de Carvalho

    2013-01-01

    Full Text Available The influences of the chemical composition and heating rate have been studied in 300 and 350 maraging steels using dilatometry. For these tests, heating was carried out with heating rates of 1, 10 and 28 °C/s. The results have shown that the precipitation mechanism for both materials in the studied range is by lattice diffusion. Furthermore, Co and Ti contents influence strongly the precipitation. The lattice diffusion mechanism in the martensite reversion is influenced by Ni and Co contents and heating rate. For small heating rates ( ~1 °C/s this mechanism prevails in the 300 maraging steel while for the 350 maraging steel has a minor importance. The mechanism of martensite reversion for 350 maraging steel in the studied range is mainly by shear mechanism. For higher heating rates (~28 ºC/s the shear mechanism prevails in both maraging steels.

  8. Liquid phase separation and rapid dendritic growth of highly undercooled ternary Fe62.5Cu27.5Sn10 alloy

    Science.gov (United States)

    Xia, Z. C.; Wang, W. L.; Luo, S. B.; Wei, B.

    2015-02-01

    The phase separation and dendritic growth characteristics of undercooled liquid Fe62.5Cu27.5Sn10 alloy have been investigated by glass fluxing and drop tube techniques. Three critical bulk undercoolings of microstructure evolution are experimentally determined as 7, 65, and 142 K. Equilibrium peritectic solidification proceeds in the small undercooling regime below 7 K. Metastable liquid phase separation takes place if bulk undercooling increases above 65 K. Remarkable macroscopic phase separation is induced providing that bulk undercooling overtakes the third threshold of 142 K. With the continuous increase of bulk undercooling, the solidified microstructure initially appears as well-branched dendrites, then displays microscale segregation morphology, and finally evolves into macrosegregation patterns. If alloy undercooling is smaller than 142 K, the dendritic growth velocity of γFe phase varies with undercooling according to a power function relationship. Once bulk undercooling exceeds 142 K, its dendritic growth velocity increases exponentially with undercooling, which reaches 30.4 m/s at the maximum undercooling of 360 K (0.21TL). As a comparative study, the liquid phase separation of Fe62.5Cu27.5Sn10 alloy droplets is also explored under the free fall condition. Theoretical calculations reveal that the thermal and solutal Marangoni migrations are the dynamic mechanisms responsible for the development of core-shell structure.

  9. MALDI-ToF mass spectrometry coupled with multivariate pattern recognition analysis for the rapid biomarker profiling of Escherichia coli in different growth phases.

    Science.gov (United States)

    Momo, Remi A; Povey, Jane F; Smales, C Mark; O'Malley, Christopher J; Montague, Gary A; Martin, Elaine B

    2013-10-01

    Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-ToF MS) has been exploited extensively in the field of microbiology for the characterisation of bacterial species, the detection of biomarkers for early disease diagnosis and bacterial identification. Here, the multivariate data analysis technique of partial least squares-discriminant analysis (PLS-DA) was applied to 'intact cell' MALDI-ToF MS data obtained from Escherichia coli cell samples to determine if such an approach could be used to distinguish between, and characterise, different growth phases. PLS-DA is a technique that has the potential to extract systematic variation from large and noisy data sets by identifying a lower-dimensional subspace that contains latent information. The application of PLS-DA to the MALDI-ToF data obtained from cells at different stages of growth resulted in the successful classification of the samples according to the growth phase of the bacteria cultures. A further outcome of the analysis was that it was possible to identify the mass-to-charge (m/z) ratio peaks or ion signals that contributed to the classification of the samples. The Swiss-Prot/TrEMBL database and primary literature were then used to provisionally assign a small number of these m/z ion signals to proteins, and these tentative assignments revealed that the major contributors from the exponential phase were ribosomal proteins. Additional assignments were possible for the stationary phase and the decline phase cultures where the proteins identified were consistent with previously observed biological interpretation. In summary, the results show that MALDI-ToF MS, PLS-DA and a protein database search can be used in combination to discriminate between 'intact cell' E. coli cell samples in different growth phases and thus could potentially be used as a tool in process development in the bioprocessing industry to enhance cell growth and cell engineering strategies.

  10. A rapid and robust assay for detection of S-phase cell cycle progression in plant cells and tissues by using ethynyl deoxyuridine

    Directory of Open Access Journals (Sweden)

    Horváth Gábor V

    2010-01-01

    Full Text Available Abstract Background Progress in plant cell cycle research is highly dependent on reliable methods for detection of cells replicating DNA. Frequency of S-phase cells (cells in DNA synthesis phase is a basic parameter in studies on the control of cell division cycle and the developmental events of plant cells. Here we extend the microscopy and flow cytometry applications of the recently developed EdU (5-ethynyl-2'-deoxyuridine-based S-phase assay to various plant species and tissues. We demonstrate that the presented protocols insure the improved preservation of cell and tissue structure and allow significant reduction in assay duration. In comparison with the frequently used detection of bromodeoxyuridine (BrdU and tritiated-thymidine incorporation, this new methodology offers several advantages as we discuss here. Results Applications of EdU-based S-phase assay in microscopy and flow cytometry are presented by using cultured cells of alfalfa, Arabidopsis, grape, maize, rice and tobacco. We present the advantages of EdU assay as compared to BrdU-based replication assay and demonstrate that EdU assay -which does not require plant cell wall digestion or DNA denaturation steps, offers reduced assay duration and better preservation of cellular, nuclear and chromosomal morphologies. We have also shown that fast and efficient EdU assay can also be an efficient tool for dual parameter flow cytometry analysis and for quantitative assessment of replication in thick root samples of rice. Conclusions In plant cell cycle studies, EdU-based S-phase detection offers a superior alternative to the existing S-phase assays. EdU method is reliable, versatile, fast, simple and non-radioactive and it can be readily applied to many different plant systems.

  11. Drivers of CO2 Emission Rates from Dead Wood Logs of 13 Tree Species in the Initial Decomposition Phase

    Directory of Open Access Journals (Sweden)

    Tiemo Kahl

    2015-07-01

    Full Text Available Large dead wood is an important structural component of forest ecosystems and a main component of forest carbon cycles. CO2 emissions from dead wood can be used as a proxy for actual decomposition rates. The main drivers of CO2 emission rates for dead wood of temperate European tree species are largely unknown. We applied a novel, closed chamber measurement technique to 360 dead wood logs of 13 important tree species in three regions in Germany. We found that tree species identity was with 71% independent contribution to the model (R2 = 0.62 the most important driver of volume-based CO2 emission rates, with angiosperms having on average higher rates than conifers. Wood temperature and fungal species richness had a positive effect on CO2 emission rates, whereas wood density had a negative effect. This is the first time that positive fungal species richness—wood decomposition relationship in temperate forests was shown. Certain fungal species were associated with high or low CO2 emission rates. In addition, as indicated by separate models for each tree species, forest management intensity, study region, and the water content as well as C and N concentration of dead wood influenced CO2 emission rates.

  12. Effect of Cooling Rate on the Longitudinal Modulus of Cu3Sn Phase of Ag-Sn-Cu Amalgam Alloy (Part II

    Directory of Open Access Journals (Sweden)

    R. H. Rusli

    2015-10-01

    Full Text Available Effects of cooling rate (at the time of solidification on the elastic constants of Cu3Sn phase of Ag-Sn-Cu dental amalgam alloy were studied. In this study, three types of alloys were made, with the composition Cu-38-37 wt% Sn by means of casting, where each alloy was subjected to different cooling rate, such as cooling on the air (AC, air blown (AB, and quenched in the water (WQ. X-ray diffraction, metallography, and Scanning Electron Microscopy with Energy Dispersive Spectroscopy studies of three alloys indicated the existence of Cu3Sn phase. Determination of the modulus of elasticity of Cu3Sn (ε phase was carried out by the measurement of longitudinal and transversal waves velocity using ultrasonic technique. The result shows that Cu3Sn (ε phase on AC gives higher modulus of elasticity values than those of Cu3Sn (ε on AB and WQ. The high modulus of elasticity value will produce a strong Ag-Sn-Cu dental amalagam alloy.

  13. Influence of the interface on growth rates in AlN/GaN short period superlattices via metal organic vapor phase epitaxy

    Science.gov (United States)

    Rodak, L. E.; Korakakis, D.

    2011-11-01

    AlN/GaN short period superlattices are well suited for a number of applications including, but not limited to, digital alloys, intersubband devices, and emitters. In this work, AlN/GaN superlattices with periodicities ranging from 10 to 20 Å have been grown via metal organic vapor phase epitaxy in order to investigate the influence of the interface on the binary alloy growth rates. The GaN growth rate at the interface was observed to decrease with increasing GaN thickness while the AlN growth rate remained constant. This has been attributed to a decrease in the decomposition rate of GaN at the hetero-interface as seen in other III-V hetero-structures.

  14. Validation of the generalized model of two-phase thermosyphon loop based on experimental measurements of volumetric flow rate

    OpenAIRE

    Bieliński Henryk

    2016-01-01

    The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the low...

  15. The effect of enemy combat tactics on PTSD prevalence rates: A comparison of Operation Iraqi Freedom deployment phases in a sample of male and female veterans.

    Science.gov (United States)

    Green, Jonathan D; Bovin, Michelle J; Erb, Sarah E; Lachowicz, Mark; Gorman, Kaitlyn R; Rosen, Raymond C; Keane, Terence M; Marx, Brian P

    2016-09-01

    Research suggests that the nature of combat may affect later development of posttraumatic stress disorder (PTSD) in combat veterans. Studies comparing rates of PTSD across different conflicts indicate that the use of asymmetric or guerilla-style tactics by enemy fighters may result in higher rates of PTSD among U.S. military personnel than the use of symmetric tactics, which mirror tactics used by U.S. forces. Investigations of the association between enemy combat tactics and PTSD across conflicts were limited because of cohort effects and a focus on male veterans. The current study examined rates of PTSD diagnosis in a sample of male and female veterans deployed to Operation Iraqi Freedom (OIF), a conflict with 3 distinct phases marked by varying enemy tactics. Participants were 738 veterans enrolled in Project VALOR (Veterans' After-Discharge Longitudinal Registry) who deployed once to OIF. Participants completed a clinician interview as well as self-report measures. Male veterans deployed during the OIF phase marked by asymmetric tactics were more than twice as likely to be diagnosed with PTSD as those deployed during the other 2 phases, even after controlling for extent of combat exposure, demographic characteristics, and other deployment-related risk factors for PTSD. Differing rates of PTSD across the 3 OIF phases were not observed among female participants. The nature of combat (specifically, asymmetric enemy tactics) may be a risk factor for the development of PTSD among males. Factors other than enemy tactics may be more important to the development of PTSD among females. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. Kinetic behaviour in supercritical fluid chromatography with modified mobile phase for 5 μm particle size and varied flow rates.

    Science.gov (United States)

    Lesellier, E; Fougere, L; Poe, Donald P

    2011-04-15

    After much development of stationary phase chemistry, in recent years the focus of many studies in HPLC has shifted to increase the efficiency and analysis speed. Ultra high pressure liquid chromatography (UHPLC) using sub-2 μm particles, and high temperature liquid chromatography (HTLC), using temperatures above 100°C have received much attention. These new approaches allow the use of flow rates higher than those classically used in HPLC, reducing the analysis duration. Due to the low viscosity of supercritical fluids, high velocities, i.e. high flow rates, can be achieved with classical pumping systems typically used in supercritical fluid chromatography (SFC). The effects of the flow rate increase with CO(2)/methanol mobile phase was studied on the inlet pressure, t(0), the retention factor of the compounds, and on the efficiency. Simple comparisons of efficiencies obtained at varied temperature between SFC and HPLC, with a packed column containing 5 μm particles, show the greater kinetic performances achieved with the CO(2)/methanol fluid, and underline specific behaviours of SFC, occurring for high flow rates and sub-ambient temperature. Some values (N/t(0)) are also compared to UHPLC data, showing that good performance can be achieved in SFC without applying drastic analytical conditions. Finally, simple kinetic plots (t(0) vs N) at constant column length are used to select combinations of temperature and flow rate necessary to achieve a required theoretical plate number. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. 210Pb-226Ra chronology reveals rapid growth rate of Madrepora oculata and Lophelia pertusa on world's largest cold-water coral reef

    Directory of Open Access Journals (Sweden)

    N. Tisnérat-Laborde

    2012-03-01

    Full Text Available Here we show the use of the 210Pb-226Ra excess method to determine the growth rate of two corals from the world's largest known cold-water coral reef, Røst Reef, north of the Arctic circle off Norway. Colonies of each of the two species that build the reef, Lophelia pertusa and Madrepora oculata, were collected alive at 350 m depth using a submersible. Pb and Ra isotopes were measured along the major growth axis of both specimens using low level alpha and gamma spectrometry and trace element compositions were studied. 210Pb and 226Ra differ in the way they are incorporated into coral skeletons. Hence, to assess growth rates, we considered the exponential decrease of initially incorporated 210Pb, as well as the increase in 210Pb from the decay of 226Ra and contamination with 210Pb associated with Mn-Fe coatings that we were unable to remove completely from the oldest parts of the skeletons. 226Ra activity was similar in both coral species, so, assuming constant uptake of 210Pb through time, we used the 210Pb-226Ra chronology to calculate growth rates. The 45.5 cm long branch of M. oculata was 31 yr with an average linear growth rate of 14.4 ± 1.1 mm yr−1 (2.6 polyps per year. Despite cleaning, a correction for Mn-Fe oxide contamination was required for the oldest part of the colony; this correction corroborated our radiocarbon date of 40 yr and a mean growth rate of 2 polyps yr−1. This rate is similar to the one obtained in aquarium experiments under optimal growth conditions. For the 80 cm-long L. pertusa colony, metal-oxide contamination remained in both the middle and basal part of the coral skeleton despite cleaning, inhibiting similar age and growth rate estimates. The youngest part of the colony was free of metal oxides and this 15 cm section had an estimated a growth rate of 8 mm yr−1, with high uncertainty (~1 polyp every two to three years. We are less certain of this 210Pb growth rate estimate which is within the lowermost

  18. Quasistatic in-depth local strain relaxation/creep rate mapping using phase-sensitive optical coherence tomography

    Science.gov (United States)

    Matveev, Lev A.; Karashtin, Dmitry A.; Sovetsky, Aleksandr A.; Gubarkova, Ekaterina V.; Sirotkina, Marina A.; Matveyev, Alexander L.; Shabanov, Dmitry V.; Gelikonov, Grigory V.; Gelikonov, Valentin M.; Druzhkova, Irina N.; Gladkova, Natalia D.; Vitkin, Alex; Zagaynova, Elena V.; Zaitsev, Vladimir Yu.

    2017-07-01

    OCT-based local strain relaxation/creep evaluation is an emerging tool for tissue viscoelasticity characterization. We present a tool for 2D visualization of local strain relaxation and creep time/rate inside the tissue.

  19. Glomerular filtration rate estimated from the uptake phase of 99mTc-DTPA renography in chronic renal failure

    DEFF Research Database (Denmark)

    Petersen, L J; Petersen, J R; Talleruphuus, U

    1999-01-01

    The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from 99mTc-DTPA renography with that estimated from the renal clearance of 51Cr-EDTA, creatinine and urea.......The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from 99mTc-DTPA renography with that estimated from the renal clearance of 51Cr-EDTA, creatinine and urea....

  20. A Lab on a chip device for rapid identification of Avian Influenza virus by on-chip sample preparation and solid phase PCR

    DEFF Research Database (Denmark)

    Yi, Sun; Dhumpa, Raghuram; Bang, Dang Duong

    2009-01-01

    In this paper, we describe a novel lab-on-a-chip device for fast AIV screening by integrating DNA microarray-based solid phase PCR on microchip. The device can handle viral samples in an automatic way. Moreover, multiplex PCR and sequence detection are done in one-step, which greatly simplifies...

  1. Electromembrane-surrounded solid-phase microextraction coupled to ion mobility spectrometry for the determination of nonsteroidal anti-inflammatory drugs: A rapid screening method in complicated matrices.

    Science.gov (United States)

    Abedi, Hamid; Ebrahimzadeh, Homeira

    2015-05-01

    A new robust method of electromembrane-surrounded solid-phase microextraction coupled to ion mobility mass spectrometry was applied for nonsteroidal anti-inflammatory drugs determination in complex matrices. This is the first time that a graphene/polyaniline composite coating is applied in electromembrane-surrounded solid-phase microextraction method. The homemade graphene/polyaniline composite is characterized by a high electrical conductivity and thermal stability. The variables affecting electromembrane-surrounded solid-phase microextraction, including extraction time; applied voltage and pH were optimized through chemometric methods, central composite design, and response surface methodology. Under the optimized conditions, limits of detection of 0.04 and 0.05 ng/mL were obtained for mefenamic acid and ibuprofen, respectively. The feasibility of electromembrane-surrounded solid-phase microextraction followed by ion mobility mass spectrometry was successfully confirmed by the extraction and determination of low levels of ibuprofen and mefenamic acid in human urine and plasma samples and satisfactory results were obtained. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Rapid decline of viral RNA in hepatitis C patients treated with VX-950: a phase Ib, placebo-controlled, randomized study

    NARCIS (Netherlands)

    Reesink, Hendrik W.; Zeuzem, Stefan; Weegink, Christine J.; Forestier, Nicole; van Vliet, Andre; van de Wetering de Rooij, Jeroen; McNair, Lindsay; Purdy, Susan; Kauffman, Robert; Alam, John; Jansen, Peter L. M.

    2006-01-01

    BACKGROUND & AIMS: VX-950 specifically inhibits the NS3.4A protease of hepatitis C and has antiviral activity in vitro. This phase I, placebo-controlled, double-blind study evaluated the antiviral activity, pharmacokinetics, and safety of VX-950 in patients with chronic hepatitis C (CHC). METHODS:

  3. Experimental investigation and simulation of temperature distributions in a 16Ah-LiMnNiCoO2 battery during rapid discharge rates

    Science.gov (United States)

    Panchal, S.; Dincer, I.; Agelin-Chaab, M.; Fraser, R.; Fowler, M.

    2017-03-01

    It is very important to have quantitative data regarding the temperature distributions of lithium-ion batteries at different discharge rates in order to design thermal management systems and also for battery thermal modellers. In this paper, the surface temperature distributions on a superior lithium polymer battery (SLPB) with lithium manganese nickel cobalt oxide (LiMnNiCoO2) cathode material (16 Ah capacity) at C/8, C/4, C/2, 1C, 2C, and 3C discharge rates are presented. Additionally, a battery thermal model is developed for this battery using a neural network approach with the Bayesian Regularization method and the simulated results are compared with experimental results in terms of temperature and voltage profiles at C/8, C/4, C/2, 1C, 2C, and 3C discharge rates. Thermal images, which were also captured during experiments with an IR camera at various discharge rates, and are reported in the paper. The results of this study show that the increased discharge rates between C/8 and 3C results in increased surface temperature distributions on the principal surface of the battery and decreased discharge capacity.

  4. Growth-Phase Sterigmatocystin Formation on Lactose Is Mediated via Low Specific Growth Rates in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Zoltán Németh

    2016-11-01

    Full Text Available Seed contamination with polyketide mycotoxins such as sterigmatocystin (ST produced by Aspergilli is a worldwide issue. The ST biosynthetic pathway is well-characterized in A. nidulans, but regulatory aspects related to the carbon source are still enigmatic. This is particularly true for lactose, inasmuch as some ST production mutant strains still synthesize ST on lactose but not on other carbon substrates. Here, kinetic data revealed that on d-glucose, ST forms only after the sugar is depleted from the medium, while on lactose, ST appears when most of the carbon source is still available. Biomass-specified ST production on lactose was significantly higher than on d-glucose, suggesting that ST formation may either be mediated by a carbon catabolite regulatory mechanism, or induced by low specific growth rates attainable on lactose. These hypotheses were tested by d-glucose limited chemostat-type continuous fermentations. No ST formed at a high growth rate, while a low growth rate led to the formation of 0.4 mg·L−1 ST. Similar results were obtained with a CreA mutant strain. We concluded that low specific growth rates may be the primary cause of mid-growth ST formation on lactose in A. nidulans, and that carbon utilization rates likely play a general regulatory role during biosynthesis.

  5. Growth-Phase Sterigmatocystin Formation on Lactose Is Mediated via Low Specific Growth Rates in Aspergillus nidulans.

    Science.gov (United States)

    Németh, Zoltán; Molnár, Ákos P; Fejes, Balázs; Novák, Levente; Karaffa, Levente; Keller, Nancy P; Fekete, Erzsébet

    2016-11-28

    Seed contamination with polyketide mycotoxins such as sterigmatocystin (ST) produced by Aspergilli is a worldwide issue. The ST biosynthetic pathway is well-characterized in A. nidulans, but regulatory aspects related to the carbon source are still enigmatic. This is particularly true for lactose, inasmuch as some ST production mutant strains still synthesize ST on lactose but not on other carbon substrates. Here, kinetic data revealed that on d-glucose, ST forms only after the sugar is depleted from the medium, while on lactose, ST appears when most of the carbon source is still available. Biomass-specified ST production on lactose was significantly higher than on d-glucose, suggesting that ST formation may either be mediated by a carbon catabolite regulatory mechanism, or induced by low specific growth rates attainable on lactose. These hypotheses were tested by d-glucose limited chemostat-type continuous fermentations. No ST formed at a high growth rate, while a low growth rate led to the formation of 0.4 mg·L(-1) ST. Similar results were obtained with a CreA mutant strain. We concluded that low specific growth rates may be the primary cause of mid-growth ST formation on lactose in A. nidulans, and that carbon utilization rates likely play a general regulatory role during biosynthesis.

  6. High-Sequence Diversity and Rapid Virus Turnover Contribute to Higher Rates of Coreceptor Switching in Treatment-Experienced Subjects with HIV-1 Viremia.

    Science.gov (United States)

    Nedellec, Rebecca; Herbeck, Joshua T; Hunt, Peter W; Deeks, Steven G; Mullins, James I; Anton, Elizabeth D; Reeves, Jacqueline D; Mosier, Donald E

    2017-03-01

    Coreceptor switching from CCR5 to CXCR4 is common during chronic HIV-1 infection, but is even more common in individuals who have failed antiretroviral therapy (ART). Prior studies have suggested rapid mutation and/or recombination of HIV-1 envelope (env) genes during coreceptor switching. We compared the functional and genotypic changes in env of viruses from viremic subjects who had failed ART just before and after coreceptor switching and compared those to viruses from matched subjects without coreceptor switching. Analysis of multiple unique functional env clones from each subject revealed extensive diversity at both sample time points and rapid diversification of sequences during the 4-month interval in viruses from both 9 subjects with coreceptor switching and 15 control subjects. Only two subjects had envs with evidence of recombination. Three findings distinguished env clones from subjects with coreceptor switching from controls: (1) lower entry efficiency via CCR5; (2) longer V1/V2 regions; and (3), lower nadir CD4 T cell counts during prior years of infection. Most of these subjects harbored virus with lower replicative capacity associated with protease (PR) and/or reverse transcriptase inhibitor resistance mutations, and the extensive diversification tended to lead either to improved entry efficiency via CCR5 or the gain of entry function via CXCR4. These results suggest that R5X4 or X4 variants emerge from a diverse, low-fitness landscape shaped by chronic infection, multiple ART resistance mutations, the availability of target cells, and reduced entry efficiency via CCR5.

  7. Rapid formation of Ni3Sn4 joints for die attachment of SiC-based high temperature power devices using ultrasound-induced transient liquid phase bonding process.

    Science.gov (United States)

    Li, Z L; Dong, H J; Song, X G; Zhao, H Y; Feng, J C; Liu, J H; Tian, H; Wang, S J

    2017-05-01

    High melting point Ni3Sn4 joints for the die attachment of SiC-based high temperature power devices was successfully achieved using an ultrasound-induced transient liquid phase (TLP) bonding process within a remarkably short bonding time of 8s. The formed intermetallic joints, which are completely composed of the refined equiaxial Ni3Sn4 grains with the average diameter of 2μm, perform the average shear strength of 26.7MPa. The sonochemical effects of ultrasonic waves dominate the mechanism and kinetics of the rapid formation of Ni3Sn4 joints. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Gas-phase rate coefficients of the reaction of ozone with four sesquiterpenes at 295 ± 2 K.

    Science.gov (United States)

    Richters, Stefanie; Herrmann, Hartmut; Berndt, Torsten

    2015-05-07

    The rate coefficients of the reaction of ozone with the four atmospherically relevant sesquiterpenes β-caryophyllene, α-humulene, α-cedrene and isolongifolene were investigated at 295 ± 2 K and atmospheric pressure by at least two independent experimental investigations for each reaction. Relative rate experiments were carried out in a flow tube using two different experimental approaches with GC-MS detection (RR 1) and PTR-MS analysis (RR 2) as the analytical techniques. Absolute rate coefficients were determined in a stopped-flow experiment following the ozone depletion by means of UV spectroscopy. The average rate coefficients from the combined investigations representing the mean values of the different experimental methods are (unit: cm(3) molecule(-1) s(-1)): k(O3+β-caryophyllene) = (1.1 ± 0.3) × 10(-14) (methods: RR 1, RR 2, absolute), k(O3+α-humulene) = (1.2 ± 0.3) × 10(-14) (RR 1, RR 2), k(O3+α-cedrene) = (1.7 ± 0.5) × 10(-16) (RR 2, absolute) and k(O3+isolongifolene) = (1.1 ± 0.5) × 10(-17) (RR 2, absolute). The high ozonolysis rate coefficients for β-caryophyllene and α-humulene agree well with the results by Shu and Atkinson (Int. J. Chem. Kinet., 1994, 26) and lead to short atmospheric lifetimes of about two minutes with respect to the ozone reaction. The relatively small rate coefficients for α-cedrene and isolongifolene differ from the available literature values by a factor of about 2.5-6. Possible reasons for the deviations are discussed. Finally, calibrated sesquiterpene FT-IR spectra were recorded for the first time.

  9. Phase transitions in tumor growth: IV relationship between metabolic rate and fractal dimension of human tumor cells

    Science.gov (United States)

    Betancourt-Mar, J. A.; Llanos-Pérez, J. A.; Cocho, G.; Mansilla, R.; Martin, R. R.; Montero, S.; Nieto-Villar, J. M.

    2017-05-01

    By the use of thermodynamics formalism of irreversible processes, complex systems theory and systems biology, it is derived a relationship between the production of entropy per unit time, the fractal dimension and the tumor growth rate for human tumors cells. The thermodynamics framework developed demonstrates that, the dissipation function is a Landau potential and also the Lyapunov function of the dynamical behavior of tumor growth, which indicate the directional character, stability and robustness of the phenomenon. The entropy production rate may be used as a quantitative index of the metastatic potential of tumors. The current theoretical framework will hopefully provide a better understanding of cancer and contribute to improvements in cancer treatment.

  10. A rapid space-resolved solid-phase microextraction method as a powerful tool to determine contaminants in wine based on their volatility.

    Science.gov (United States)

    Liu, Min; Peng, Qing-Qing; Chen, Yu-Feng; Tang, Qian; Feng, Qing

    2015-06-01

    A novel space-resolved solid phase microextraction (SR-SPME) technique was developed to facilitate simultaneously analyte monitoring within heterogeneous samples. Graphene (G) and graphene oxide (GO) were coated separately to the segmented fibers which were successfully used for the solid-phase microextraction of two contaminants with dramatically different volatility: 2,4,6-trichloroanisole (TCA) and dibutyl phthalate (DBP). The space-resolved fiber showed good precision (5.4%, 6.8%), low detection limits (0.3ng/L, 0.3ng/L), and wide linearity (1.0-250.0ng/L, 1.0-250.0ng/L) under the optimized conditions for TCA and DBP, respectively. The method was applied to simultaneous analysis of the two contaminates with satisfactory recoveries, which were 96.96% and 98.20% for wine samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Rapid analysis of phthalates in beverage and alcoholic samples by multi-walled carbon nanotubes/silica reinforced hollow fibre-solid phase microextraction.

    Science.gov (United States)

    Li, Jia; Su, Qiong; Li, Ke-Yao; Sun, Chu-Feng; Zhang, Wen-Bo

    2013-12-15

    A novel procedure based on multi-walled carbon nanotubes (MWCNTs)/silica reinforced hollow fibre solid-phase microextraction combined with gas chromatography-mass spectrometry has been developed to analyse trace phthalate acid esters in beverage and alcoholic samples. Because of their excellent adsorption capability towards hydrophobic compounds, functionalized MWCNTs, acting as solid-phase sorbent, were co-deposited with silica particles in the pores of polypropylene hollow fibre through a layer-by-layer self-assembly technique. The parameters influencing the extraction efficiency, such as pH values and ionic strength of sample solution, extraction time, temperature and desorption solvent were optimised. Recoveries for phthalates at spiking levels in different matrices were satisfactory (between 68% and 115%). Moreover, the results were further confirmed by comparing them with those obtained using a solvent extraction method according to the national standard of China. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. A rapid method for the simultaneous quantification of the major tocopherols, carotenoids, free and esterified sterols in canola (Brassica napus) oil using normal phase liquid chromatography.

    Science.gov (United States)

    Flakelar, Clare L; Prenzler, Paul D; Luckett, David J; Howitt, Julia A; Doran, Gregory

    2017-01-01

    A normal phase high performance liquid chromatography (HPLC) method was developed to simultaneously quantify several prominent bioactive compounds in canola oil vis. α-tocopherol, γ-tocopherol, δ-tocopherol, β-carotene, lutein, β-sitosterol, campesterol and brassicasterol. The use of sequential diode array detection (DAD) and tandem mass spectrometry (MS/MS) allowed direct injection of oils, diluted in hexane without derivatisation or saponification, greatly reducing sample preparation time, and permitting the quantification of both free sterols and intact sterol esters. Further advantages over existing methods included increased analytical selectivity, and a chromatographic run time substantially less than other reported normal phase methods. The HPLC-DAD-MS/MS method was applied to freshly extracted canola oil samples as well as commercially available canola, palm fruit, sunflower and olive oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Linear Electro Optic Effect for High Repetition Rate Carrier Envelope Phase Control of Ultra Short Laser Pulses

    Directory of Open Access Journals (Sweden)

    Michel Comte

    2013-02-01

    Full Text Available This paper is devoted to analyzing the principle and applications of the linear electro-optic (EO effect for the control of the carrier-envelope-phase (CEP. We introduce and detail here an original method, which relies on the use of an EO dispersive prism pair in a compressor-like configuration. We show that, by choosing an adequate geometry, it is possible to shift the CEP without changing the group delay (isochronous carrier-envelope-phase shifter or change the induced group delay without varying the CEP. According to our calculations, when applying an electric field around 400 V/cm to the rubidium titanyle phosphate (RTP prisms in a double pass configuration (2 × 40 mm total length, one obtains a CEP shift of π rad at 800 nm without inducing a group delay. In contrast, this CEP shift is obtained for an electric field around 1.4 kV/cm in a RTP rectangular slab of the same total length and, in this case, the group delay is of the order of a few fs.

  14. Solid-phase PCR for rapid multiplex detection of Salmonella spp. at the subspecies level, with amplification efficiency comparable to conventional PCR.

    Science.gov (United States)

    Chin, Wai Hoe; Sun, Yi; Høgberg, Jonas; Hung, Tran Quang; Wolff, Anders; Bang, Dang Duong

    2017-04-01

    Solid-phase PCR (SP-PCR) has attracted considerable interest in different research fields since it allows parallel DNA amplification on the surface of a solid substrate. However, the applications of SP-PCR have been hampered by the low efficiency of the solid-phase amplification. In order to increase the yield of the solid-phase amplification, we studied various parameters including the length, the density, as well as the annealing position of the solid support primer. A dramatic increase in the signal-to-noise (S/N) ratio was observed when increasing the length of solid support primers from 45 to 80 bp. The density of the primer on the surface was found to be important for the S/N ratio of the SP-PCR, and the optimal S/N was obtained with a density of 1.49 × 1011 molecules/mm2. In addition, the use of solid support primers with a short overhang at the 5' end would help improve the S/N ratio of the SP-PCR. With optimized conditions, SP-PCR can achieve amplification efficiency comparable to conventional PCR, with a limit of detection of 1.5 copies/μl (37.5 copies/reaction). These improvements will pave the way for wider applications of SP-PCR in various fields such as clinical diagnosis, high-throughput DNA sequencing, and single-nucleotide polymorphism analysis. Graphical abstract Schematic representation of solid-phase PCR.

  15. Disperse magnetic solid phase microextraction and surface enhanced Raman scattering (Dis-MSPME-SERS) for the rapid detection of trace illegally chemicals.

    Science.gov (United States)

    Yu, Shihua; Liu, Zhigang; Wang, Weixian; Jin, Li; Xu, Weiqing; Wu, Yuqing

    2018-02-01

    The technique of solid phase micro-extraction (SPME) is an important method for sample pretreatment in analytical chemistry, especially for the analysis in micro-systems. Surface enhanced Raman scattering (SERS) is an ultra-sensitive and fast detection technique. Both are particularly important in qualitative analysis of trace amount of substance. In this study, combining the magnetic nanoparticles with magnetic SPME device, we develop a high efficient new pretreatment method named as disperse magnetic solid phase micro-extraction (Dis-MSPME). In comparison to the traditional SPME, the proposed Dis-MSPME realizes solid phase micro-extraction from dispersive system, which improved the extraction efficiency largely. Conjunction the advantages both of Dis-MSPME and SERS is proposed as Dis-MSPME-SERS as a new detection method, which realize enrichment, magnetic separation and detection all-in-one. Making it a simpler, more efficient and sensitive approach in identifying the illegal additives. Sildenafil citrate (SC) in 500μL health wine as an example of illegal additive was successfully detected in a LOD of 1.0 × 10-8M. Moreover, comparative study on the extract efficient of Dis-MSPME-SERS with SPME-SERS shows it takes only 10min to detect sildenafil citrate in the health wine, from enrichment to detection by Dis-MSPME-SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Data Science Innovations That Streamline Development, Documentation, Reproducibility, and Dissemination of Models in Computational Thermodynamics: An Application of Image Processing Techniques for Rapid Computation, Parameterization and Modeling of Phase Diagrams

    Science.gov (United States)

    Ghiorso, M. S.

    2014-12-01

    Computational thermodynamics (CT) represents a collection of numerical techniques that are used to calculate quantitative results from thermodynamic theory. In the Earth sciences, CT is most often applied to estimate the equilibrium properties of solutions, to calculate phase equilibria from models of the thermodynamic properties of materials, and to approximate irreversible reaction pathways by modeling these as a series of local equilibrium steps. The thermodynamic models that underlie CT calculations relate the energy of a phase to temperature, pressure and composition. These relationships are not intuitive and they are seldom well constrained by experimental data; often, intuition must be applied to generate a robust model that satisfies the expectations of use. As a consequence of this situation, the models and databases the support CT applications in geochemistry and petrology are tedious to maintain as new data and observations arise. What is required to make the process more streamlined and responsive is a computational framework that permits the rapid generation of observable outcomes from the underlying data/model collections, and importantly, the ability to update and re-parameterize the constitutive models through direct manipulation of those outcomes. CT procedures that take models/data to the experiential reference frame of phase equilibria involve function minimization, gradient evaluation, the calculation of implicit lines, curves and surfaces, contour extraction, and other related geometrical measures. All these procedures are the mainstay of image processing analysis. Since the commercial escalation of video game technology, open source image processing libraries have emerged (e.g., VTK) that permit real time manipulation and analysis of images. These tools find immediate application to CT calculations of phase equilibria by permitting rapid calculation and real time feedback between model outcome and the underlying model parameters.

  17. Disparity mutagenesis model possesses the ability to realize both stable and rapid evolution in response to changing environments without altering mutation rates.

    Directory of Open Access Journals (Sweden)

    Ichiro Fujihara

    2016-08-01

    As long as the fidelity difference between the lagging and leading strand was kept high enough, the robustness of the disparity model was very high. The acceleration or slowdown of evolution can be unambiguously introduced only by environmental changes, and the seesawing mutation rate is not the necessary condition for changing the speed of evolution.

  18. Dynamic aspects of the continuity illusion: perception of level and of the depth, rate, and phase of modulation

    NARCIS (Netherlands)

    Lyzenga, J.; Carlyon, R.P.; Moore, B.C.

    2005-01-01

    The perception of modulation of a tone interrupted by a noise burst was investigated. The tone and its modulation were perceived as continuing through the noise. In experiment 1, subjects rated the similarity of an uninterrupted tone and a tone interrupted by noise, in terms of the perceived level

  19. Intraspecific Allometry of Basal Metabolic Rate : Relations with Body Size, Temperature, Composition, and Circadian Phase in the Kestrel, Falco tinnunculus

    NARCIS (Netherlands)

    Daan, Serge; Masman, Dirkjan; Strijkstra, Arjen; Verhulst, Simon

    1989-01-01

    The relationship between body size and basal metabolic rate (BMR) in homeotherms has been treated in the literature primarily by comparison between species of mammals or birds. This paper focuses on the intraindividual changes in BMR when body mass (W) varies with different maintenance regimens. BMR

  20. Effect of mixing rate and temperature on primary Si phase of hypereutectic Al-20Si alloy during controlled diffusion solidification (CDS process

    Directory of Open Access Journals (Sweden)

    Yuan-dong Li

    2015-05-01

    Full Text Available Controlled Diffusion Solidification (CDS is a promising process relied on mixing two liquid alloys of precisely controlled chemistry and temperature in order to produce a predetermined alloy composition. In this study, the CDS was employed to prepare hypereutectic Al-20%Si (mass fraction alloy using Al-30%Si and pure Al of different temperatures. The mixing rate was controlled using three small crucibles with a hole of different diameters in their bottom. The effect of mixing rate and temperature on the microstructure of the primary Si-phase during the mixing of molten Al and Al-30%Si was studied. The results showed that when the diameter of the small crucible bottom hole is 16 mm, a higher mass mixing rate 0.217 kg·s-1 would results in a lower stream velocity 0.414 m·s-1. Conversely a lower mass mixing rate 0.114 kg·s-1 (the diameter of the small crucible bottom hole is 8 mm would result in a higher fluid stream velocity 0.879 m·s-1. A lower mass mixing rate would be better to refine the primary Si than a higher mass mixing rate. Meanwhile, the morphology and distribution of primary Si could also be improved. Especially, when Al-30%Si alloy at 820 °C was mixed with pure Al at 670 °C in the case of a mass mixing rate of 0.114 kg·s-1 and a pouring temperature of 680 °C, the average size of the primary Si phase would be only 18.2 μm. Its morphology would mostly be octahedral and the primary Si would distribute uniformly in the matrix microstructure. The lower mass mixing rate (0.114 kg·s-1 will enhance the broken tendency of Al-30%Si steam and the mixing agitation of resultant melt, so the primary Si phase can be better refined.

  1. From micron to mountain-scale, using accessory phase petrochronology to quantify the rates of deformation in the Himalaya and beyond

    Science.gov (United States)

    Mottram, C. M.

    2016-12-01

    Mountains form where the Earth's plates collide; during this upheaval rocks are deformed by massive forces. The rates and timescales over which these deformational processes occur are determined from tiny accessory minerals that record geological time through radioactive decay. However, there remain major unresolved challenges in using chemical and microstructural markers to link the dates yielded from these accessory phases to specific deformation events and discerning the effects of deformation on the isotopic and elemental tracers in these phases. Here, the chemical signatures and deformation textures from micron-scale accessory phases are used to decode the record of mountain belt-scale deformational processes encrypted in the rocks. The Himalayan orogen is used as an ideal natural laboratory to understand the chemical processes that have modified the Earth's crust during orogenesis. Combined laser ablation split-stream U-Th-Pb and REE analysis of deformed monazite and titanite, along with Electron BackScatter Diffraction (EBSD) imaging and Pressure-Temperature (P-T) phase equilibria modelling are used to: (1) link accessory phase `age' to `metamorphic stage'; (2) to quantify the influence of deformation on monazite (re)crystallisation mechanisms and its subsequent effect on the crystallographic structure, ages and trace-element distribution in individual grains; and (3) understand how deformation is accommodated through different chemical and structural processes that operate at varying scales through time. This study highlights the importance of fully integrating the pressure-temperature-time-deformation history of multiple accessory phases to better interpret the deformational history of the cores of evolving mountain belts.

  2. Liquid-phase reduction synthesis of mono-dispersed gold nanoparticles on glass microfluidic device with flow rate control

    Science.gov (United States)

    Tanabe, Yu; Yagyu, Hiromasa

    2017-02-01

    Gold nanoparticles (GNPs) in aqueous dispersion were synthesized on a low-cost glass microfluidic device developed by authors. The effect of a channel width and a flow rate on the size distribution of synthesized GNPs was reported for synthesis of mono-dispersed GNPs. A soda-lime glass substrates was processed by the micropowder blasting. Three holes were processed on the upper substrate, and Y-shaped microchannel was processed on the bottom substrate. Tetrachloroauric (III) acid aqueous solution for Au ion and the mixture of aqueous solution of sodium citrate acid for reducing agent and tannic acid for the protective agent were injected to a microchannel in the device by syringe pump. From the analysis of absorption peak at around 530nm in absorption spectrum, the synthesized GNPs on the device has sharpen peak in comparison with that of GNPs synthesized on the beaker. Moreover, the spectrum with low flow rate showed a sharpened peak in comparison with that of high rate. In the channel width of 260μm, the full width at half maximum (FWHM) at the absorption peak affecting to a distribution of diameter of GNPs were 79.2nm for 0.05mL/min and 92.9nm for 0.06mL/min. Conversely, FWHM in the channel width of 430μm showed almost constant value. From TEM images, the synthesized GNPs using the channel width of 260μm at the flow rate of 0.05mL/min was found to have the mean diameter of 11.5nm and coefficient of variation of 0.09. These results confirmed that the combination of low flow rate and small channel width were attributed to realizing the mono-dispersed GNPs.

  3. Modulation of atomic exit and injection rates on the phase-dependent gain without inversion in a Doppler broadened open four-level system

    Science.gov (United States)

    Liu, Zhong-Bo; Jia, Ke-Ning; Liang, Ying; Tong, Dian-Min; Fan, Xi-Jun

    2012-06-01

    It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate (R0) and the ratio (S) of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with Ro increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case.

  4. Purification of quinoline yellow components using high-speed counter-current chromatography by stepwise increasing the flow-rate of the mobile phase.

    Science.gov (United States)

    Oka, Hisao; Harada, Ken-Ichi; Suzuki, Masanao; Fujii, Kiyonaga; Iwaya, Masato; Ito, Yuko; Goto, Tomomi; Matsumoto, Hiroshi; Ito, Yoichiro

    2003-03-14

    Quinoline yellow (Color Index No. 47005) consists of multiple components that show a large difference in their partition coefficients (K), ranging from 0.03 to 3.3 in the solvent system tert.-butyl methyl ether (MTBE)-1-butanol-acetonitrile-aqueous 0.1 M trifluoroacetic acid (TFA). Consequently, it requires an excessively long elution time for the simultaneous separation of all components by the standard high-speed counter-current chromatography technique, which uses a constant flow-rate of the mobile phase. In order to overcome this problem, we increased the flow-rate of the mobile phase stepwise from 0.1 to 2.0 mL/min. Using this new procedure, six components (0.2-6.1 mg) were successfully isolated from 25 mg of a commercial quinoline yellow preparation in a single run using a two-phase solvent system composed of MTBE-1-butanol-acetonitrile-aqueous 0.1 M TFA (1:3:1:5, v/v). The purified components were analyzed by high-performance liquid chromatography, electrospray ionization mass spectrometry, and nuclear magnetic resonance spectroscopy.

  5. Equilibrium Fermi's Golden Rule Charge Transfer Rate Constants in the Condensed Phase: The Linearized Semiclassical Method vs Classical Marcus Theory.

    Science.gov (United States)

    Sun, Xiang; Geva, Eitan

    2016-05-19

    In this article, we present a comprehensive comparison between the linearized semiclassical expression for the equilibrium Fermi's golden rule rate constant and the progression of more approximate expressions that lead to the classical Marcus expression. We do so within the context of the canonical Marcus model, where the donor and acceptor potential energy surface are parabolic and identical except for a shift in both the free energies and equilibrium geometries, and within the Condon region. The comparison is performed for two different spectral densities and over a wide range of frictions and temperatures, thereby providing a clear test for the validity, or lack thereof, of the more approximate expressions. We also comment on the computational cost and scaling associated with numerically calculating the linearized semiclassical expression for the rate constant and its dependence on the spectral density, temperature, and friction.

  6. Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

    Science.gov (United States)

    Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

    2016-03-01

    To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves. © IMechE 2016.

  7. Predictions of homogeneous nucleation rates for n-alkanes accounting for the diffuse phase interface and capillary waves.

    Science.gov (United States)

    Planková, Barbora; Vinš, Václav; Hrubý, Jan

    2017-10-28

    Homogeneous droplet nucleation has been studied for almost a century but has not yet been fully understood. In this work, we used the density gradient theory (DGT) and considered the influence of capillary waves (CWs) on the predicted size-dependent surface tensions and nucleation rates for selected n-alkanes. The DGT model was completed by an equation of state (EoS) based on the perturbed-chain statistical associating fluid theory and compared to the classical nucleation theory and the Peng-Robinson EoS. It was found that the critical clusters are practically free of CWs because they are so small that even the smallest wavelengths of CWs do not fit into their finite dimensions. The CWs contribute to the entropy of the system and thus decrease the surface tension. A correction for the effect of CWs on the surface tension is presented. The effect of the different EoSs is relatively small because by a fortuitous coincidence their predictions are similar in the relevant range of critical cluster sizes. The difference of the DGT predictions to the classical nucleation theory computations is important but not decisive. Of the effects investigated, the most pronounced is the suppression of CWs which causes a sizable decrease of the predicted nucleation rates. The major difference between experimental nucleation rate data and theoretical predictions remains in the temperature dependence. For normal alkanes, this discrepancy is much stronger than observed, e.g., for water. Theoretical corrections developed here have a minor influence on the temperature dependency. We provide empirical equations correcting the predicted nucleation rates to values comparable with experiments.

  8. High growth rate GaN on 200 mm silicon by metal-organic vapor phase epitaxy for high electron mobility transistors

    Science.gov (United States)

    Charles, M.; Baines, Y.; Bavard, A.; Bouveyron, R.

    2018-02-01

    It is increasingly important to reduce the cycle time of epitaxial growth, in order to reduce the costs of device fabrication, especially for GaN based structures which typically have growth cycles of several hours. We have performed a comprehensive study using metal-organic vapor phase epitaxy (MOVPE) investigating the effects of changing GaN growth rates from 0.9 to 14.5 μm/h. Although there is no significant effect on the strain incorporated in the layers, we have seen changes in the surface morphology which can be related to the change in dislocation behaviour and surface diffusion effects. At the small scale, as seen by AFM, increased dislocation density for higher growth rates leads to increased pinning of growth terraces, resulting in more closely spaced terraces. At a larger scale of hundreds of μm observed by optical profiling, we have related the formation of grains to the rate of surface diffusion of adatoms using a random walk model, implying diffusion distances from 30 μm for the highest growth rates up to 100 μm for the lowest. The increased growth rate also increases the intrinsic carbon incorporation which can increase the breakdown voltage of GaN films. Despite an increased threading dislocation density, these very high growth rates of 14.5 μm/hr by MOVPE have been shown to be appealing for reducing epitaxial growth cycle times and therefore costs in High Electron Mobility Transistor (HEMT) structures.

  9. Efficacy and safety of a 4-factor prothrombin complex concentrate for rapid vitamin K antagonist reversal in Japanese patients presenting with major bleeding or requiring urgent surgical or invasive procedures: a prospective, open-label, single-arm phase 3b study.

    Science.gov (United States)

    Kushimoto, Shigeki; Fukuoka, Toshio; Kimura, Akio; Toyoda, Kazunori; Brainsky, Andres; Harman, Amy; Chung, Thomas; Yasaka, Masahiro

    2017-12-01

    Rapid vitamin K antagonist (VKA) reversal is required in patients experiencing major bleeding or requiring urgent surgery. Four-factor prothrombin complex concentrate (4F-PCC; Beriplex®/Kcentra®) was shown in two large randomized controlled, international phase 3b trials to be an effective alternative to plasma for urgent VKA reversal. In the present prospective, open-label, single-arm phase 3b trial, we evaluate the efficacy and safety of 4F-PCC in Japanese patients. Eleven patients [international normalized ratio (INR) ≥2] requiring rapid VKA reversal owing to major bleeding (n = 6) or before urgent surgical/invasive procedures (n = 5) were administered 4F-PCC dosed based on INR and weight. INR reduction (≤1.3 0.5 h postinfusion; primary endpoint) was achieved in 81.8% of patients (major bleeding, 83.3%; surgical/invasive procedures, 80.0%). Effective hemostasis (main secondary endpoint) was met in 60.0% (major bleeding) and 100% (surgical/invasive procedure) of evaluable patients. Adverse events (AEs) and serious AEs were reported in 90.9 and 45.5% of patients, respectively. Two AEs were considered treatment-related; thromboembolic events rated mild and not clinically relevant by investigators. There were no deaths, fluid overload events, or viral transmission cases. Consistent with the previous results, 4F-PCC may be an effective and well-tolerated treatment for rapid VKA reversal in Japanese patients experiencing major bleeding or requiring urgent surgical/invasive procedures.

  10. Thermokarst Caves, Baydzherakhs, and Thaw Subsidence, Oh My! Combining Ground Based Geophysics and Survey Measurements With Airborne LiDAR to Understand Rates and Patterns of Rapid Permafrost Thaw

    Science.gov (United States)

    Douglas, T. A.; Hiemstra, C. A.; Bjella, K.

    2016-12-01

    Arctic and sub-Arctic discontinuous permafrost regions are nearing thaw instability. Warming temperatures, human or natural disturbance, altered precipitation, or a shift in the timing of seasonal transitions can lead to dramatic landscape changes on timescales of a few years. Much of the permafrost thaw surface expression is controlled by melting subsurface ice features, and these "hot spot" locations are currently not specifically mapped and are likely increasing in number and areal distribution. Tools are needed to identify where, how, and at what rate thermokarst, thaw subsidence, and altered hydrologic flowpaths develop. Galvanic coupled resistivity tomography (GRT) allows for an indirect qualitative identification of permafrost; frozen versus thawed, and ice-rich versus ice-poor. When GRT is combined with aboveground repeat imagery and LiDAR spatial information, permafrost landscape change can be detected and rates and scales of this change ascertained. This can also be combined with vegetation and ecological measurements to identify how rapidly subsurface changes in permafrost alter hydrologic and biogeochemical cycles. We are combining GRT, borehole mapping, airborne and ground-based LiDAR, and snow, soil, and vegetation measurements at a variety of Interior Alaska locations where permafrost landscapes have been exhibiting rapid change. Our features include an area where hillslope erosion developed subsurface thermokarst caverns meters deep and tens of meters long following intense summer precipitation events. We are studying thermokarst at a 600-m long lake that rapidly drained to expose a field of baydzherakhs meters tall and 5-10 meter across. We have also been monitoring rapid degradation and subsidence in lowland ice rich permafrost. The results from this study suggest the expression of permafrost degradation and thermokarst formation across the landscape are readily apparent and quantifiable. Baseline and recurrent surveying with these coupled

  11. Heat transfer rate distribution on North American Rockwell delta wing orbiter determined by phase change paint technique at a Mach number of 8, volume 1

    Science.gov (United States)

    Matthews, R. K.; Martindale, W. R.; Warmbrod, J. D.

    1972-01-01

    The results of a wind tunnel test program to determine aerodynamic heat transfer distributions on an orbiter configuration are presented. Heat-transfer rates were determined by the phase change paint technique on 0.013-scale Stycast models using Tempilaq as the surface temperature indicator. The nominal test conditions were; Mach 8, length Reynolds numbers of 6.0 x 1 million and 8.9 x 1 million, and angles of attack from 10 to 50 deg in 10-deg increments. At the higher Reynolds number, data were obtained with and without boundary layer trips. Model details, test conditions, and reduced heat-transfer data are presented. Data reduction of the phase-change paint photographs was performed by utilizing a new technique which is described in the data presentation section.

  12. Heat transfer rate distributions on McDonnell-Douglas booster determined by phase change technique for nominal Mach number of 8

    Science.gov (United States)

    Matthews, R. K.; Martindale, W. R.; Warmbrod, J. D.

    1972-01-01

    The results of a wind tunnel test program to determine aerodynamic heat transfer distributions on the McDonnell Douglas Booster configuration are presented. Heat-transfer rates were determined by the phase-change paint technique on 0.009-scale Stycast models using Tempilaq as the surface temperature indicator. The nominal test conditions were; Mach 8, length Reynolds numbers 5 million and 7.3 million, and angles of attack of 40, 50, and 60 deg. At the higher Reynolds number, data were obtained with and without boundary layer trips. Model details, test conditions, and reduced heat-transfer data are presented. Data reduction of the phase-change paint photographs was performed by utilizing a new technique which is described.

  13. A rapid hydrolysis method and DABS-Cl derivatization for complete amino acid analysis of octreotide acetate by reversed phase HPLC.

    Science.gov (United States)

    Akhlaghi, Yousef; Ghaffari, Solmaz; Attar, Hossein; Alamir Hoor, Amir

    2015-11-01

    Octreotide as a synthetic cyclic octapeptide is a somatostatin analog with longer half-life and more selectivity for inhibition of the growth hormone. The acetate salt of octreotide is currently used for medical treatment of somatostatin-related disorders such as endocrine and carcinoid tumors, acromegaly, and gigantism. Octreotide contains both cysteine and tryptophan residues which make the hydrolysis part of its amino acid analysis procedure very challenging. The current paper introduces a fast and additive-free method which preserves tryptophan and cysteine residues during the hydrolysis. Using only 6 M HCl, this hydrolysis process is completed in 30 min at 150 °C. This fast hydrolysis method followed by pre-column derivatization of the released amino acids with 4-N,N-dimethylaminoazobenzene-4'-sulfonyl chloride (DABS-Cl) which takes only 20 min, makes it possible to do the complete amino acid analysis of an octreotide sample in a few hours. The highly stable-colored DABS-Cl derivatives can be detected in 436 nm in a reversed phase chromatographic system, which eliminates spectral interferences to a great extent. The amino acid analysis of octreotide acetate including hydrolysis, derivatization, and reversed phase HPLC determination was validated according to International Conference of Harmonization (ICH) guidelines.

  14. Rapid determination of acetone in human plasma by gas chromatography-mass spectrometry and solid-phase microextraction with on-fiber derivatization.

    Science.gov (United States)

    Deng, Chunhui; Zhang, Wei; Zhang, Jie; Zhang, Xiangmin

    2004-06-15

    Acetone is an important volatile disease marker. Due to its nature of activity and volatility, it is a difficult task to measure the concentration of acetone in biological samples with accuracy. In this paper, we developed a novel method for determination of trace amount acetone in human plasma by solid-phase microextraction technique with on-fiber derivatization. In this method, the poly(dimethylsiloxane)/divinylbenzene (PDMS/DVB) fiber was used and O-2,3,4,5,6-(pentafluorobenzyl) hydroxylamine hydrochloride (PFBHA) was first loaded on the fiber. Acetone in plasma sample was agitated into headspace and extracted by solid-phase microextraction (SPME) fiber and subsequently derivatized with PFBHA on the fiber. Acetone oxime was analyzed by gas chromatography-mass spectrometry (GC-MS). Quantitative analysis of acetone in plasma was carried out by using external standard method. The SPME conditions (extraction temperature and time) and the method validation were studied. The present method was tested by determination of acetone in diabetes plasma and normal plasma. Acetone concentration in diabetes plasma was found to be higher than 1.8mM, while in normal plasma was lower than 0.017 mM. The results show that the present method is a potential tool for diagnosis of diabetes.

  15. Which luteal phase support is better for each IVF stimulation protocol to achieve the highest pregnancy rate? A superiority randomized clinical trial.

    Science.gov (United States)

    Gizzo, Salvatore; Andrisani, Alessandra; Esposito, Federica; Noventa, Marco; Di Gangi, Stefania; Angioni, Stefano; Litta, Pietro; Gangemi, Michele; Nardelli, Giovanni Battista

    2014-01-01

    In vitro fertilization (IVF) cycles generate abnormalities in luteal-phase sex steroid concentrations and this represent an important limiting factor to achieve a good pregnancy rate. Although there are evidences about the usefulness of luteal phase support (LPS) after IVF cycles, no consensus exist about the best dose and way of progesterone (PG) administration, the advantages of estradiol (E2) supplementation and which IVF protocol could benefit from one more than other LPS scheme. Aim of the study was to assess the best LPS (low-dose PG, high-dose PG, high-dose PG and E2 supplementation) to achieve the highest clinical/ongoing pregnancy rate according to stimulation protocol, E2 at ovulation induction, endometrial thickness at pick-up and women's age. We conducted a randomized trial on 360 women undergoing IVF (180 treated by long-GnRH agonist, 90 by short-GnRH agonist and 90 by short-GnRH antagonist protocol) and stimulated by recombinant follicle-stimulating hormone alone. Our data demonstrated that high-dose PG is better than low-dose to increase both clinical and ongoing pregnancy rate. E2 supplementation are mandatory in case of short-GnRH antagonist protocol and strongly suggested in all protocols when E2max 35 years, the real advantages of E2 supplementation remain debatable and require further confirmation.

  16. On the deposition of volatiles and semivolatiles from cigarette smoke aerosols: relative rates of transfer of nicotine and ammonia from particles to the gas phase.

    Science.gov (United States)

    Seeman, Jeffrey I; Lipowicz, Peter J; Piadé, Jean-Jacques; Poget, Laurent; Sanders, Edward B; Snyder, James P; Trowbridge, Clarence G

    2004-08-01

    The hypothesis that elevated levels of ammonia-releasing compounds in tobacco and ammonia in mainstream (MS) smoke increase the rate and amount of nicotine evaporation from the particles of MS smoke aerosol was examined by kinetic modeling and experiments with MS cigarette smoke. Computational simulation of a kinetic mechanism describing volatile loss of nicotine, ammonia, and acetic acid from an aqueous solution was used to compute the time-dependent concentration of all species in the model. Because of the high volatility of ammonia relative to that of nicotine, variation over a wide range of initial ammonia concentration had no significant effect upon the rate of loss of nicotine from the model system. The effects of a variation in the volatile loss rate constant for ammonia and for the acid were examined. The simulations show that ammonia is lost from the model solution at a greater rate than nicotine and acid, and the loss of volatile acid has a significant role in the rate and amount of nicotine loss. Simulations with a model system undergoing a continuous steady addition of ammonia showed that high rates of ammonia addition could significantly increase the rate of nicotine volatile loss from the model solution. A series of smoking experiments was performed using blended cigarettes connected to a denuder tube. Deposition of smoke constituents can occur directly from the gas phase and by the deposition of smoke aerosol particles themselves. As nicotine exists >99% in the particle phase of MS smoke, in the absence of particle deposition, denuder tube deposition of nicotine occurs via the evaporation-deposition pathway. Solanesol, a nonvolatile tobacco and smoke terpene, was used to quantify the amount of particle deposition onto the denuder tube. The amount of ammonia deposited on the denuder tube was an order of magnitude greater than that of nicotine, showing that ammonia evaporates from the MS smoke particles much faster than does nicotine. The experimental

  17. Retrieval of kinetic rates in reactions with semi batch liquid phase using ill-posed inverse problem theory

    Directory of Open Access Journals (Sweden)

    Rita C. O. Sebastião

    2011-01-01

    Full Text Available A neural network procedure to solve inverse chemical kinetic problems is discussed in this work. Rate constants are calculated from the product concentration of an irreversible consecutive reaction: the hydrogenation of Citral molecule, a process with industrial interest. Simulated and experimental data are considered. Errors in the simulated data, up to 7% in the concentrations, were assumed to investigate the robustness of the inverse procedure. Also, the proposed method is compared with two common methods in nonlinear analysis; the Simplex and Levenberg-Marquardt approaches. In all situations investigated, the neural network approach was numerically stable and robust with respect to deviations in the initial conditions or experimental noises.

  18. PEP3 overexpression shortens lag phase but does not alter growth rate in Saccharomyces cerevisiae exposed to acetic acid stress

    Science.gov (United States)

    Ding, Jun; Holzwarth, Garrett; Bradford, C. Samuel; Cooley, Ben; Yoshinaga, Allen S.; Patton-Vogt, Jana; Abeliovich, Hagai; Penner, Michael H.; Bakalinsky, Alan T.

    2017-01-01

    In fungi, two recognized mechanisms contribute to pH homeostasis: the plasma membrane proton-pumping ATPase that exports excess protons and the vacuolar proton-pumping ATPase (V-ATPase) that mediates vacuolar proton uptake. Here, we report that overexpression of PEP3 which encodes a component of the HOPS and CORVET complexes involved in vacuolar biogenesis, shortened lag phase in Saccharomyces cerevisiae exposed to acetic acid stress. By confocal microscopy, PEP3-overexpressing cells stained with the vacuolar membrane-specific dye, FM4-64 had more fragmented vacuoles than the wild-type control. The stained overexpression mutant was also found to exhibit about 3.6-fold more FM4-64 fluorescence than the wild-type control as determined by flow cytometry. While the vacuolar pH of the wild-type strain grown in the presence of 80 mM acetic acid was significantly higher than in the absence of added acid, no significant difference was observed in vacuolar pH of the overexpression strain grown either in the presence or absence of 80 mM acetic acid. Based on an indirect growth assay, the PEP3-overexpression strain exhibited higher V-ATPase activity. We hypothesize that PEP3 overexpression provides protection from acid stress by increasing vacuolar surface area and V-ATPase activity and, hence, proton-sequestering capacity. PMID:26051671

  19. Two-phase olive mill waste composting: enhancement of the composting rate and compost quality by grape stalks addition.

    Science.gov (United States)

    Cayuela, Maria Luz; Sánchez-Monedero, Miguel A; Roig, Asunción

    2010-06-01

    Two-phase olive mill waste (TPOMW) is a semisolid sludge generated by the olive oil industry. Its recycling as a soil amendment, either unprocessed or composted, is being promoted as a beneficial agricultural practice in the Mediterranean area. One of the major difficulties when composting TPOMW is the compaction of the material due to its dough-like texture, which leads to an inadequate aeration. For this reason, the addition of bulking agents is particularly important to attain a proper composting process. In this study we followed the evolution of two composting mixtures (A and B) prepared by mixing equal amounts of TPOMW and sheep litter (SL) (in a dry weight basis). In pile B grape stalks (GS) were added (10% dry weight) as bulking agent to study their effect on the development of the composting process and the final compost quality. The incorporation of grape stalks to the composting mixture changed the organic matter (OM) degradation dynamics and notably reduced the total amount of lixiviates. The evolution of several maturation indices (C/N, germination index, water soluble carbon, humification indices, C/N in the leachates) showed a faster and improved composting process when GS were added. Moreover, chemical (NH4+, NO3(-), cation exchange capacity, macro and micronutrients, heavy metals) and physical properties (bulk and real densities, air content, total water holding capacity, porosity) of the final composts were analysed and confirmed the superior quality of the compost where GS were added.

  20. PEP3 overexpression shortens lag phase but does not alter growth rate in Saccharomyces cerevisiae exposed to acetic acid stress.

    Science.gov (United States)

    Ding, Jun; Holzwarth, Garrett; Bradford, C Samuel; Cooley, Ben; Yoshinaga, Allen S; Patton-Vogt, Jana; Abeliovich, Hagai; Penner, Michael H; Bakalinsky, Alan T

    2015-10-01

    In fungi, two recognized mechanisms contribute to pH homeostasis: the plasma membrane proton-pumping ATPase that exports excess protons and the vacuolar proton-pumping ATPase (V-ATPase) that mediates vacuolar proton uptake. Here, we report that overexpression of PEP3 which encodes a component of the HOPS and CORVET complexes involved in vacuolar biogenesis, shortened lag phase in Saccharomyces cerevisiae exposed to acetic acid stress. By confocal microscopy, PEP3-overexpressing cells stained with the vacuolar membrane-specific dye, FM4-64 had more fragmented vacuoles than the wild-type control. The stained overexpression mutant was also found to exhibit about 3.6-fold more FM4-64 fluorescence than the wild-type control as determined by flow cytometry. While the vacuolar pH of the wild-type strain grown in the presence of 80 mM acetic acid was significantly higher than in the absence of added acid, no significant difference was observed in vacuolar pH of the overexpression strain grown either in the presence or absence of 80 mM acetic acid. Based on an indirect growth assay, the PEP3-overexpression strain exhibited higher V-ATPase activity. We hypothesize that PEP3 overexpression provides protection from acid stress by increasing vacuolar surface area and V-ATPase activity and, hence, proton-sequestering capacity.

  1. An Empirical Method Permitting Rapid Determination of the Area, Rate and Distribution of Water-Drop Impingement on an Airfoil of Arbitrary Section at Subsonic Speeds

    Science.gov (United States)

    Bergrun, N. R.

    1951-01-01

    An empirical method for the determination of the area, rate, and distribution of water-drop impingement on airfoils of arbitrary section is presented. The procedure represents an initial step toward the development of a method which is generally applicable in the design of thermal ice-prevention equipment for airplane wing and tail surfaces. Results given by the proposed empirical method are expected to be sufficiently accurate for the purpose of heated-wing design, and can be obtained from a few numerical computations once the velocity distribution over the airfoil has been determined. The empirical method presented for incompressible flow is based on results of extensive water-drop. trajectory computations for five airfoil cases which consisted of 15-percent-thick airfoils encompassing a moderate lift-coefficient range. The differential equations pertaining to the paths of the drops were solved by a differential analyzer. The method developed for incompressible flow is extended to the calculation of area and rate of impingement on straight wings in subsonic compressible flow to indicate the probable effects of compressibility for airfoils at low subsonic Mach numbers.

  2. A study on the physical fitness index, heart rate and blood pressure in different phases of lunar month on male human subjects

    Science.gov (United States)

    Chakraborty, Ujjwal; Ghosh, Tusharkanti

    2013-09-01

    The gravitational pull of the moon on the earth is not the same in all phases of the lunar month, i.e. new moon (NM), first quarter (FQ), full moon (FM) and third quarter (TQ), and as a result the amplitude of tide differs in different phases. The gravitational pull of the moon may have effects on the fluid compartments of the human body and hence the cardiovascular system may be affected differentially in the different phases of the lunar month. In the present study resting heart rate (HR) and blood pressure (BP), physical fitness index (PFI), peak HR and BP immediately after step test, and recovery HR and BP after step test were measured during different phases of the lunar month in 76 male university students (age 23.7 ± 1.7 years). At rest, both systolic and mean arterial BP were ˜5 mmHg lower in NM and FM compared to FQ and TQ, but resting HR was not significantly different between phases. Further, peak HR and peak systolic BP after step test were lower (˜4 beat/min and ˜5 mmHg, respectively) in NM and FM compared to FQ and TQ. PFI was also higher (˜5) in NM and FM compared to FQ and TQ. Recovery of HR after step test was quicker in NM and FM compared to that of FQ and TQ. It appears from this study that gravitational pull of the moon may affect the cardiovascular functions of the human body. Moreover, the physical efficiency of humans is increased in NM and FM due to these altered cardiovascular regulations.

  3. SU-F-P-39: End-To-End Validation of a 6 MV High Dose Rate Photon Beam, Configured for Eclipse AAA Algorithm Using Golden Beam Data, for SBRT Treatments Using RapidArc

    Energy Technology Data Exchange (ETDEWEB)

    Ferreyra, M; Salinas Aranda, F; Dodat, D; Sansogne, R; Arbiser, S [Vidt Centro Medico, Ciudad Autonoma De Buenos Aires, Ciudad Autonoma de Buenos Aire (Argentina)

    2016-06-15

    Purpose: To use end-to-end testing to validate a 6 MV high dose rate photon beam, configured for Eclipse AAA algorithm using Golden Beam Data (GBD), for SBRT treatments using RapidArc. Methods: Beam data was configured for Varian Eclipse AAA algorithm using the GBD provided by the vendor. Transverse and diagonals dose profiles, PDDs and output factors down to a field size of 2×2 cm2 were measured on a Varian Trilogy Linac and compared with GBD library using 2% 2mm 1D gamma analysis. The MLC transmission factor and dosimetric leaf gap were determined to characterize the MLC in Eclipse. Mechanical and dosimetric tests were performed combining different gantry rotation speeds, dose rates and leaf speeds to evaluate the delivery system performance according to VMAT accuracy requirements. An end-to-end test was implemented planning several SBRT RapidArc treatments on a CIRS 002LFC IMRT Thorax Phantom. The CT scanner calibration curve was acquired and loaded in Eclipse. PTW 31013 ionization chamber was used with Keithley 35617EBS electrometer for absolute point dose measurements in water and lung equivalent inserts. TPS calculated planar dose distributions were compared to those measured using EPID and MapCheck, as an independent verification method. Results were evaluated with gamma criteria of 2% dose difference and 2mm DTA for 95% of points. Results: GBD set vs. measured data passed 2% 2mm 1D gamma analysis even for small fields. Machine performance tests show results are independent of machine delivery configuration, as expected. Absolute point dosimetry comparison resulted within 4% for the worst case scenario in lung. Over 97% of the points evaluated in dose distributions passed gamma index analysis. Conclusion: Eclipse AAA algorithm configuration of the 6 MV high dose rate photon beam using GBD proved efficient. End-to-end test dose calculation results indicate it can be used clinically for SBRT using RapidArc.

  4. A rapid solid-phase extraction method for measurement of non-metabolised peripheral benzodiazepine receptor ligands, [{sup 18}F]PBR102 and [{sup 18}F]PBR111, in rat and primate plasma

    Energy Technology Data Exchange (ETDEWEB)

    Katsifis, Andrew, E-mail: andrew.katsifis@ansto.gov.a [ANSTO LifeSciences, Sydney, 2234 (Australia); Loc' h, Christian [ANSTO LifeSciences, Sydney, 2234 (Australia); Henderson, David [Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Sydney, 2050 (Australia); Bourdier, Thomas; Pham, Tien; Greguric, Ivan [ANSTO LifeSciences, Sydney, 2234 (Australia); Lam, Peter [Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Sydney, 2050 (Australia); Callaghan, Paul; Mattner, Filomena [ANSTO LifeSciences, Sydney, 2234 (Australia); Eberl, Stefan [Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Sydney, 2050 (Australia); School of Information Technology, University of Sydney, Sydney, 2006 (Australia); Fulham, Michael [Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Sydney, 2050 (Australia); School of Information Technology, University of Sydney, Sydney, 2006 (Australia); Sydney Medical School, University of Sydney, Sydney, 2006 (Australia)

    2011-01-15

    Objectives: To develop a rapid and reliable method for estimating non-metabolised PBR ligands fluoroethoxy ([{sup 18}F]PBR102)- and fluoropropoxy ([{sup 18}F]PBR111)-substituted 2-(6-chloro-2-phenyl)imidazo[1,2-a]pyridine-3-yl)-N,N-diethylacetamides in plasma. Methods: Rats and baboons were imaged with PET up to 2 h postinjection of [{sup 18}F]PBR102 and [{sup 18}F]PBR111 under baseline conditions, after pre-blocking or displacement with PK11195. Arterial plasma samples were directly analysed by reverse-phase solid-phase extraction (RP-SPE) and RP-HPLC and by normal-phase TLC. SPE cartridges were successively washed with acetonitrile/water mixtures. SPE eluant radioactivity was measured in a {gamma}-counter to determine the parent compound fraction and then analysed by HPLC and TLC for validation. Results: In SPE, hydrophilic and lipophilic radiolabelled metabolites were eluted in water and 20% acetonitrile/water. All non-metabolised [{sup 18}F]PBR102 and [{sup 18}F]PBR111 were in SPE acetonitrile fraction as confirmed by HPLC and TLC analysis. Unchanged (%) [{sup 18}F]PBR102 and [{sup 18}F]PBR111 from SPE analysis in rat and baboon plasma agreed with those from HPLC and TLC analysis. In rats and baboons, the fraction of unchanged tracer followed a bi-exponential decrease, with half-lives of 7 to 10 min for the fast component and >80 min for the slow component for both tracers. Conclusions: Direct plasma SPE analysis of [{sup 18}F]PBR102 and [{sup 18}F]PBR111 can reliably estimate parent compound fraction. SPE was superior to HPLC for samples with low activity; it allows rapid and accurate metabolite analysis of a large number of plasma samples for improved estimation of metabolite-corrected input function during quantitative PET imaging studies.

  5. Rapid analysis of Achillea tenuifolia Lam essential oils by polythiophene/hexagonally ordered silica nanocomposite coating as a solid-phase microextraction fibre.

    Science.gov (United States)

    Piryaei, Marzieh; Abolghasemi, Mir Mahdi; Nazemiyeh, Hossein

    2015-01-01

    In this work, a highly porous fibre coated with polythiophene/hexagonally ordered silica nanocomposite (PT/SBA-15) was prepared and used for extraction of essential oils with microwave-assisted distillation headspace solid phase microextraction (MA-HS-SPME) method. The prepared nanomaterials were immobilised on a stainless steel wire for fabrication of the SPME fibre. Using MA-HS-SPME followed by GC-MS, 24 compounds were separated and identified in Achillea tenuifolia, which mainly included limonene (28.6%), α-cadinol (12.7%), borneol (6.7%), caryophyllene oxide (3.2%), bornyl acetate (4.3%), camphene (3.2%) and para-cymene (2.3%). The experimental results showed that the polythiophene/hexagonally ordered silica nanocomposite fibres were suitable for the semi-quantitative study of the composition of essential oils in plant materials and for monitoring the variations in the volatile components of the plants.

  6. Rapid Screening for Potential Epitopes Reactive with a Polycolonal Antibody by Solution-Phase H/D Exchange Monitored by FT-ICR Mass Spectrometry

    Science.gov (United States)

    Zhang, Qian; Noble, Kyle A.; Mao, Yuan; Young, Nicolas L.; Sathe, Shridhar K.; Roux, Kenneth H.; Marshall, Alan G.

    2013-07-01

    The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.

  7. Impacts of uncertainty in AVOC emissions on the summer RO x budget and ozone production rate in the three most rapidly-developing economic growth regions of China

    Science.gov (United States)

    Wang, Feng; An, Junling; Li, Ying; Tang, Yujia; Lin, Jian; Qu, Yu; Chen, Yong; Zhang, Bing; Zhai, Jing

    2014-11-01

    High levels of uncertainty in non-methane volatile organic compound (NMVOC) emissions in China could lead to significant variation in the budget of the sum of hydroxyl (OH) and peroxy (HO2, RO2) radicals (RO x = OH + HO2 + RO2) and the ozone production rate [P(O3)], but few studies have investigated this possibility, particularly with three-dimensional air quality models. We added diagnostic variables into the WRF-Chem model to assess the impact of the uncertainty in anthropogenic NMVOC (AVOC) emissions on the RO x budget and P(O3) in the Beijing-Tianjin-Hebei region, Yangtze River Delta, and Pearl River Delta of China. The WRF-Chem simulations were compared with satellite and ground observations, and previous observation-based model studies. Results indicated that 68% increases (decreases) in AVOC emissions produced 4%-280% increases (2%-80% decreases) in the concentrations of OH, HO2, and RO2 in the three regions, and resulted in 35%-48% enhancements (26%-39% reductions) in the primary RO x production and ˜ 65% decreases (68%-73% increases) of the P(O3) in Beijing, Shanghai, and Guangzhou. For the three cities, the two largest contributors to the RO x production rate were the reaction of O1D + H2O and photolysis of HCHO, ALD2, and others; the reaction of OH + NO2 (71%-85%) was the major RO x sink; and the major contributor to P(O3) was the reaction of HO2 + NO (˜ 65%). Our results showed that AVOC emissions in 2006 from Zhang et al. (2009) have been underestimated by ˜ 68% in suburban areas and by > 68% in urban areas, implying that daily and hourly concentrations of secondary organic aerosols and inorganic aerosols could be substantially underestimated, and cloud condensation nuclei could be underestimated, whereas local and regional radiation was overestimated.

  8. A high repetition rate TEA CO II laser operating at λ=9.3-μm for the rapid and conservative ablation and modification of dental hard tissues

    Science.gov (United States)

    Fan, Kenneth; Fried, Daniel

    2006-02-01

    TEA CO II lasers tuned to the strong mineral absorption of hydroxyapatite near λ=9-μm are ideally suited for the efficient ablation of dental hard tissues if the laser-pulse is stretched to greater than 5-10-μs to avoid plasma shielding phenomena. Such CO II lasers are capable of operating at high repetition rates for the rapid removal of dental hard tissues. An Impact 2500 TEA CO II laser system from GSI Lumonics (Rugby, UK) custom modified by LightMachinery (Ottawa, Canada) with a repetition rate of 0-500 Hz was used for rapid tissue removal. The single pulse ablation rates through enamel were determined for incident fluence ranging from (1-160 J/cm2). Lateral incisions using a computer controlled scanning stage and water spray were produced and the crater morphology and chemical composition were measured using optical microscopy and high-resolution synchrotron radiation infrared spectromicroscopy. The transmission through 2-meter length 300, 500, 750 and 1000-μm silica hollow waveguides was measured and 80% transmission was achieved with 40-mJ per pulse. The λ=9.3-μm laser pulses efficiently removed dental enamel at rates exceeding 15-μm per pulses with minimal heat accumulation. The residual energy remaining in tooth samples was measured to be 30-40% without water cooling, significantly lower than for longer CO II laser pulses. These results suggest that high repetition rate TEA CO II laser systems operating at λ=9.3-μm with pulse durations of 10-20-μs are ideally suited for dental application.

  9. Rapid and sensitive analysis of phthalate metabolites, bisphenol A, and endogenous steroid hormones in human urine by mixed-mode solid-phase extraction, dansylation, and ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry.

    Science.gov (United States)

    Wang, He-xing; Wang, Bin; Zhou, Ying; Jiang, Qing-wu

    2013-05-01

    Steroid hormone levels in human urine are convenient and sensitive indicators for the impact of phthalates and/or bisphenol A (BPA) exposure on the human steroid hormone endocrine system. In this study, a rapid and sensitive method for determination of 14 phthalate metabolites, BPA, and ten endogenous steroid hormones in urine was developed and validated on the basis of ultra-performance liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry. The optimized mixed-mode solid phase-extraction separated the weakly acidic or neutral BPA and steroid hormones from acidic phthalate metabolites in urine: the former were determined in positive ion mode with a methanol/water mobile phase containing 10 mM ammonium formate; the latter were determined in negative ion mode with a acetonitrile/water mobile phase containing 0.1 % acetic acid, which significantly alleviated matrix effects for the analysis of BPA and steroid hormones. Dansylation of estrogens and BPA realized simultaneous and sensitive analysis of the endogenous steroid hormones and BPA in a single chromatographic run. The limits of detection were less than 0.84 ng/mL for phthalate metabolites and less than 0.22 ng/mL for endogenous steroid hormones and BPA. This proposed method had satisfactory precision and accuracy, and was successfully applied to the analyses of human urine samples. This method could be valuable when investigating the associations among endocrine-disrupting chemicals, endogenous steroid hormones, and relevant adverse outcomes in epidemiological studies.

  10. A quantum method for thermal rate constant calculations from stationary phase approximation of the thermal flux-flux correlation function integral.

    Science.gov (United States)

    Aieta, Chiara; Ceotto, Michele

    2017-06-07

    This paper presents a quantum mechanical approximation to the calculation of thermal rate constants. The rate is derived from a suitable stationary phase approximation to the time integral of the thermal flux-flux correlation function. The goal is to obtain an expression that barely depends on the position of the flux operators, i.e., of the dividing surfaces, so that it can be applied also to complex systems by arbitrarily locating the dividing surfaces. The approach is tested on one and two dimensional systems where quantum effects are predominant over a wide range of temperatures. The results are quite accurate, i.e., within a few percent of the exact values for a reasonable range of dividing surface positions.

  11. Predicting arene rate coefficients with respect to hydroxyl and other free radicals in the gas-phase: a simple and effective method using a single topological descriptor

    Directory of Open Access Journals (Sweden)

    M. R. McGillen

    2007-07-01

    Full Text Available The reactivity of aromatic compounds is of great relevance to pure and applied chemical disciplines, yet existing methods for estimating gas-phase rate coefficients for their reactions with free radicals lack accuracy and universality. Here a novel approach is taken, whereby strong relationships between rate coefficients of aromatic hydrocarbons and a Randić-type topological index are investigated, optimized and developed into a method which requires no specialist software or computing power.

    Measured gas-phase rate coefficients for the reaction of aromatic hydrocarbons with OH radicals were correlated with a calculated Randić-type index, and optimized by including a term for side chain length. Although this method is exclusively for use with hydrocarbons, it is more diverse than any single existing methodology since it incorporates alkenylbenzenes into correlations, and can be extended towards other radical species such as O(3P (and tentatively NO3, H and Cl. A comparison (with species common to both techniques is made between the topological approach advocated here and a popular approach based on electrophilic subsituent constants, where it compares favourably.

    A modelling study was carried out to assess the impact of using estimated rate coefficients as opposed to measured data in an atmospheric model. The difference in model output was negligible for a range of NOx concentrations, which implies that this method has utility in complex chemical models.

    Strong relationships (e.g. for OH, R2=0.96 between seemingly diverse compounds including benzene, multisubstituted benzenes with saturated, unsaturated, aliphatic and cyclic substitutions and the nonbenzenoid aromatic, azulene suggests that the Randić-type index presented here represents a new and effective way of describing aromatic reactivity, based on a quantitative structure-activity relationship (QSAR.

  12. Studies in Phylogeny, Development of Rapid IdentificationMethods, Antifungal Susceptibility, and Growth Rates of Clinical Strains of Sporothrix schenckii Complex in Japan.

    Science.gov (United States)

    Suzuki, Rumi; Yikelamu, Alimu; Tanaka, Reiko; Igawa, Ken; Yokozeki, Hiroo; Yaguchi, Takashi

    2016-01-01

    Sporotrichosis is a fungal infection caused by the Sporothrix species, which have distinct virulence profiles and geographic distributions. We performed a phylogenetic study in strains morphologically identified as Sporothrix schenckii from clinical specimens in Japan, which were preserved at the Medical Mycology Research Center, Chiba University. In addition, we examined the in vitro antifungal susceptibility and growth rate to evaluate their physiological features. Three hundred strains were examined using sequence analysis of the partial calmodulin gene, or polymerase chain reaction(PCR)method using newly designed species-specific primers; 291 strains were Sporothrix globosa and 9 strains were S. schenckii sensu stricto (in narrow sense, s. s.). S. globosa strains were further clustered into two subclades, and S. schenckii s. s. strains were divided into three subclades. In 38 strains of S. globosa for which antifungal profiles were determined, 4 strains (11%) showed high minimal inhibitory concentration (MIC) value for itraconazole. All tested strains of S. schenckii s. s. and S. globosa showed low sensitivity for amphotericin B. These antifungals are used for treatment of sporotrichosis when infection is severe. S. schenckii s. s. grew better than S. globosa; wherein S. globosa showed restricted growth at 35℃ and did not grow at 37℃. Our molecular data showed that S. globosa is the main causal agent of sporotrichosis in Japan. It is important to determine the antifungal profiles of each case, in addition to accurate species-level identification, to strategize the therapy for sporotrichosis.

  13. Development of C14 laves phase alloy for battery with good high-rate dischargeability; Koritsu hoden tokusei no sugureta denchiyo C14gata laves sogokin no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, H.; Wakao, S. [Tokai Univ., Tokyo (Japan); Mori, K. [Daido Steel Co. Ltd., Aichi (Japan)

    1998-07-05

    Authors have studied to develop Zr-Ti-V-Ni-Mn-Co(Fe,Mo) laves phase alloys for Ni-MH secondary batteries. The object of this study was to develop C14 laves phase alloys with good high-rate dischargeability. Alloys with enthalpy -triangleH for hydride formation in the range of 35 to 37 kJ/molH2 were designed using relations among the enthalpy, cell volume, and average atomic radius. The agreement between designed values and experimental results, and the differences of the enthalpy, cell volume and electrochemical characteristics, alloys with and without heat treatment, were studied. This paper describes first the principle of designing the alloys. Then the method of the experiment was explained The results and considerations were stated under the headings, i.e. Percentage of phase and cell volume, Enthalpy for hydride formation, Electrochemical characteristics of heat treated alloys and the same of as-cast alloys. 12 refs., 5 figs., 3 tabs.

  14. Preliminary studies on the use of solid-phase immunosorbent techniques for the rapid detection of Wesselsbron virus (WSLV) IgM by haemagglutination-inhibition.

    Science.gov (United States)

    Baba, S S; Fagbami, A H; Ojeh, C K

    1999-01-01

    Serum samples from 446 randomly selected persons belonging to different age groups and locations in Nigeria were tested for the presence of WSLV IgM using the flavivirus haemagglutination-inhibition (HI) test adopted to the solid-phase immunosorbent technique (SPIT). 61 (14%) persons had IgM to WSLV only, while 9 (2%) persons had heterologous IgM to WSLV and two other flaviviruses, namely yellow fever and Uganda S viruses. There was a high prevalence of IgM in people of younger age groups than those in older groups. The majority of the IgM positive sera (67 (96%) of the 70 positive sera reacted to high titres (>21:80). With the conventional HI tests, 314 (70%) of the total sera tested had HI antibodies to one or more flaviviruses (yellow fever, West Nile, Potiskum, Zika and Uganda S) out of which 305/314 (97%) had antibodies to 3 or more flaviviruses used in the tests. Although SPIT may not be as sensitive as the conventional HI test, it was found to be more specific and could be adopted for the detection of early WSLV infections in flavivirus hyperendemic environments.

  15. A rapid, sensitive and validated method for the determination of ondansetron in human plasma by reversed-phase high-pressure liquid chromatography.

    Science.gov (United States)

    Chandrasekar, Durairaj; Ramakrishna, Sistla; Diwan, Prakash V

    2004-01-01

    A simple and sensitive method for the determination of ondansetron (CAS 116002-70-1) in human plasma was developed using high-pressure liquid chromatography (HPLC). The procedure involves extraction of human plasma with tertiary butyl methyl ether containing 2 mol/l sodium hydroxide, followed by reversed-phase HPLC using a LiChrospher 100 RP-18e 5 microm column and UV detection at 305 nm. The retention times of ondansetron and internal standard (propranolol hydrochloride, CAS 318-98-9) were 9.38 and 13.40 min, respectively. The calibration curves were linear over the range of 10 ng/ml (lower limit of quantitation, LOQ) and 380 ng/ml for ondansetron. The intra- and inter-assay coefficients of variation for all the criteria of validation were less than 15% over the linearity range. Ondansetron was stable upon storage in human plasma. The sensitivity and precision of the method were within the accepted limits (< 15 %) throughout the validation period. The present method is useful for determination of plasma concentrations of ondansetron during human pharmacokinetic studies.

  16. Pipette tip solid-phase extraction and ultra-performance liquid chromatography/mass spectrometry based rapid analysis of picrosides from Picrorhiza scrophulariiflora.

    Science.gov (United States)

    Shen, Qing; Dong, Wei; Wang, Yixuan; Gong, Like; Dai, Zhiyuan; Cheung, Hon-Yeung

    2013-06-01

    Pipette tip solid-phase extraction (PT-SPE) is a technique popular in sample preparation of biological fluids and protein hydrolysates. In this study, we developed a microtechnic using a pipette tip packed with C18 as sorbent for extraction and purification of bioactive compounds, picroside-I, II and III, in crude herbal extracts from Picrorhiza scrophulariiflora (P. scrophulariiflora). Compared to conventional SPE, PT-SPE is fast, easy to operate, and the tools are very accessible (pipette tip and tube, without expensive SPE set-up). Moreover, it is also cost-effective because significant amount of sorbent and solvents can be saved. The eluate was analyzed by ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). Afterwards, the method was fully validated and the results demonstrated that the PT-SPE-UPLC-MS/MS method is an excellent technique for analysis of the herbal medicine. Finally, this PT-SPE-UPLC-MS/MS strategy was successfully applied to analyze the crude extracts from P. scrophulariiflora samples within 10min (2min for PT-SPE and 8min for UPLC), 3.5mL solvents (including water, 0.3mL for PT-SPE and 3.2mL for UPLC), and 2mg C18 sorbent for each sample. We believe this method to be very practical and, in particular, to be suitable for widespread herbal medicine analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Studies of second phase particles in different zirconium alloys using extractive carbon replica and an electrolytic anodic dissolution procedure [rapid communication

    Science.gov (United States)

    Toffolon-Masclet, Caroline; Brachet, Jean-Christophe; Jago, Gilles

    2002-10-01

    Zirconium alloys are widely studied for applications as cladding tubes and structural components of PWR fuel assemblies. Due to their influence on some of the alloys properties (corrosion resistance, irradiation growth, …), the crystallographic structure and the chemical stoichiometry of the second phase particles (SPP) precipitated in these alloys have to be well established. The aim of this paper is to present the results obtained using two methods of SPP extractions. The first one, the extractive carbon replica method, allowed us to determine the chemical composition of SPP in different zirconium alloys: Zr-Sn-Fe-Cr (Zircaloy-4 ®), Zr-Sn-Fe-Cr-(V,Mo), Zr-Nb and Zr-Nb-Fe alloys. The second one, an anodic dissolution procedure of the matrix, is an interesting way of isolating SPP from the surrounding α-Zr matrix, giving access to a precise determination of the crystallographic structure and lattice parameters of the SPP by X-ray diffraction. This procedure was validated for Zy-4 by comparing the SPP size distribution obtained by extraction with that directly measured on a massive Zy-4 alloy (i.e. the SPP size distributions were the same for both measurements).

  18. Rapid determination of five antibiotic residues in swine wastewater by online solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Tagiri-Endo, Misako; Suzuki, Shigeru; Nakamura, Tomoyuki; Hatakeyama, Takashi; Kawamukai, Kazuo

    2009-02-01

    A simple and quick online solid-phase extraction (SPE) coupled to liquid chromatography (LC)/tandem mass spectrometry (MS/MS) for the determination of the five antibiotics (florfenicol, FF; lincomycin, LCM; oxytetracyclin, OTC; tylosin, TS; valnemulin, VLM) in swine wastewater has been developed. After filtration, aliquots (100 microl) of wastewater samples were directly injected to a column-switching LC system. Some matrix interference was removed by washing up SPE column with 0.2% formic acid solution and acetonitrile. Antibiotics eluted from SPE column were separated on analytical column by converting switching valve and were detected by MS/MS. Calibration curves using the method of standard addition had very good correlation coefficients (r > 0.99) in the range of 0.1 to 2 ng/ml. The intra-day precision of the method was less than 12% and the inter-day precision was between 6 to 17%. The detection limits were 0.01-0.1 ng/ml. When this method was applied to wastewater samples in swine facilities, four compounds (LCM, OTC, TS, and VLM) were detected.

  19. A Rapid LC-HRMS Method for the Determination of Domoic Acid in Urine Using a Self-Assembly Pipette Tip Solid-Phase Extraction.

    Science.gov (United States)

    Zhang, Yiping; Chen, Dawei; Hong, Zhuan

    2015-12-29

    In this study, we developed a self-assembly pipette tip solid-phase extraction (PTSPE) method using a high molecular weight polymer material (PAX) as the adsorbent for the determination of domoic acid (DA) in human urine samples by liquid chromatography high-resolution mass spectrometry (LC-HRMS) analysis. The PTSPE cartridge, assembled by packing 9.1 mg of PAX as sorbent into a 200 μL pipette tip, showed high adsorption capacity for DA owing to the strong cationic properties of PAX. Compared with conventional SPE, the PTSPE is simple and fast, and shows some advantages in the aspects of less solvent consumption, low cost, the absence of the evaporation step, and short time requirement. All the parameters influencing the extraction efficiency such as pH, the amount of sorbent, the number of aspirating/dispensing cycles, and the type and volume of eluent in PTSPE were carefully investigated and optimized. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of DA were 0.12 μg/L and 0.37 μg/L respectively. The extraction recoveries of DA from the urine samples spiked at four different concentrations were in a range from 88.4% to 102.5%. The intra- and inter-day precisions varied from 2.1% to 7.6% and from 2.6% to 12.7%, respectively. The accuracy ranged from -1.9% to -7.4%.

  20. A Combined Aqueous Two-Phase System and Spot-Test Platform for the Rapid Detection of Escherichia coli O157:H7 in Milk.

    Science.gov (United States)

    Cheung, Sherine F; Yee, Matthew F; Le, Nguyen K; Gomes, Elizabeth A; Afrasiabi, Zahra; Kamei, Daniel T

    2017-09-01

    Foodborne illnesses are a public health concern in the United States and worldwide. Recent outbreaks of Escherichia coli O157:H7 have brought to light the need for improved ways to detect foodborne pathogens and minimize serious outbreaks. Unfortunately, current methods for the detection of foodborne pathogens are time intensive and complex. In this study, we designed a spot immunoassay that uses a UCON-potassium phosphate salt aqueous two-phase system (ATPS) for the preconcentration of O157:H7. This platform was tested with samples of O157:H7 spiked in phosphate-buffered saline and milk. The ATPS was found to improve the detection limit of the spot test, yielding detection at 10(6) cfu/mL within 30 min. This is the first known application of ATPSs to spot immunoassays. Moreover, detection was successfully achieved without upstream processing or dilution of the sample prior to testing, thereby further simplifying the detection process. This technology's ease of use, sensitivity, and short time to result highlight its potential to advance the spot test as a viable diagnostic tool for foodborne pathogens.

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

    Directory of Open Access Journals (Sweden)

    Giorgia La Barbera

    2017-04-01

    Full Text Available 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.

  2. Phased cell division, specific division rates and other biological observations of Dinophysis populations in sub-surface layers off the south coast of Ireland

    Science.gov (United States)

    Farrell, Hazel; Velo-Suarez, Lourdes; Reguera, Beatriz; Raine, Robin

    2014-03-01

    The proportions of viable cells of Dinophysis spp. that were paired (dividing) and recently divided during a cell cycle were measured on populations of D. acuta and D. acuminata observed off the south coast of Ireland in July 2007 and July 2009. Both species exhibited phased cell division in 2009 with maximum frequency of division (fmax) 2 h after sunrise. Different patterns of division (timing of fmax) were shown by D. acuta in 2007, when the population aggregated in a thin layer was transported by a coastal jet flow. High resolution (decimetre-scale) profiles within the thin layer showed large differences in the vertical distribution of biological properties (feeding status, mortality). Values of the specific growth rate μ were compared to estimates derived in similar fashion from observations on Dinophysis populations elsewhere. Different patterns exhibited by the same species in different regions may be attributed to adaptations to latitudinal differences (length of photoperiod). The question of whether phased cell division always occurs in Dinophysis populations, and the incorporation of the potential specific division rate into models of Dinophysis growth are discussed. Comprehensive field data sets demonstrate the impact of the results on the coherence of Dinophysis populations during their transport along the Irish coast in jet-like flows towards sites of intensive shellfish culture.

  3. Effect of higher heating rate during continuous annealing on microstructure and mechanical properties of cold-rolled 590 MPa dual-phase steel

    Directory of Open Access Journals (Sweden)

    Deng Yonggang

    2015-01-01

    Full Text Available In this presentation, the effect of higher heating rate in continuous annealing on microstructure and mechanical properties of a cold-rolled 590 MPa ferrite-martensite dual-phase steel were investigated by using microstructural observation and mechanical property measurement. The results show that compared with the conventional continuous annealed steels heated at a rate of 5 ∘C/s (CA, the average ferrite grain sizes heated at a higher rate (300 ∘C/s, HRA was obviously refined from 15.6 μm to 5.3 μm. The morphology of martensite is observed to shift from network along ferrite grain boundaries to uniformly dispersed in the final DP590 microstructure. Twinned substructure of martensite can be found when heated at a higher heating rate in continuous annealing. EBSD orientation maps show that the fraction of low angle grain boundary is increased in HRA sample compared to CA sample. The HRA sample has excellent mechanical properties when compared to the CA sample. The variations of strength, elongation, strain hardening behavior and fracture mechanism of the this DP590 steel with different heating routine were further discussed in relation to microstructural features.

  4. An evaluation of combat application tourniquets on training military personnel: changes in application times and success rates in three successive phases.

    Science.gov (United States)

    Unlu, Aytekin; Kaya, E; Guvenc, I; Kaymak, S; Cetinkaya, R A; Lapsekili, E O; Ozer, M T; Guler, A; Yildiz, R; Petrone, P; Harlak, A; Kilic, S

    2015-12-01

    Haemorrhage from the injured extremity is a significant cause of preventable death in military settings. This study evaluated the effect of training on the efficacy of the combat application tourniquet (CAT) and to define standards for military personnel. Participants from a training tank battalion were randomised. Data collected included age, body mass index, mean arterial pressure, hand dominance, femoral artery diameter and skin thickness. The study involved tourniquet application times (AT) and application success rates in basic, after-training and eyes-closed phases. Doppler ultrasound was used to identify the presence or absence of popliteal, radial and ulnar artery pulses. A total of 102 trainees participated. In the after-training phase, the left and right upper extremity ATs were 35 ± 13.1 s, and 34.8 ± 13.5 s and the right and left lower extremity ATs were 20.6 ± 6.0 s and 20.5 ± 5.5 s, respectively. The overall tourniquet success rates in three successive study phases were 69.6%, 82.4% and 91.2%, respectively. A negative significant relationship was found between extremity circumference and tourniquet success. The results show that the efficacy of CAT application increases with training. Further studies are required to investigate the reasons underlying application failures. This single group prospective randomised study involves level of evidence 4. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  5. A Rapid LC-HRMS Method for the Determination of Domoic Acid in Urine Using a Self-Assembly Pipette Tip Solid-Phase Extraction

    Directory of Open Access Journals (Sweden)

    Yiping Zhang

    2015-12-01

    Full Text Available In this study, we developed a self-assembly pipette tip solid-phase extraction (PTSPE method using a high molecular weight polymer material (PAX as the adsorbent for the determination of domoic acid (DA in human urine samples by liquid chromatography high-resolution mass spectrometry (LC-HRMS analysis. The PTSPE cartridge, assembled by packing 9.1 mg of PAX as sorbent into a 200 μL pipette tip, showed high adsorption capacity for DA owing to the strong cationic properties of PAX. Compared with conventional SPE, the PTSPE is simple and fast, and shows some advantages in the aspects of less solvent consumption, low cost, the absence of the evaporation step, and short time requirement. All the parameters influencing the extraction efficiency such as pH, the amount of sorbent, the number of aspirating/dispensing cycles, and the type and volume of eluent in PTSPE were carefully investigated and optimized. Under the optimized conditions, the limit of detection (LOD and limit of quantification (LOQ values of DA were 0.12 μg/L and 0.37 μg/L respectively. The extraction recoveries of DA from the urine samples spiked at four different concentrations were in a range from 88.4% to 102.5%. The intra- and inter-day precisions varied from 2.1% to 7.6% and from 2.6% to 12.7%, respectively. The accuracy ranged from −1.9% to −7.4%.

  6. Pressure drop-flow rate curves for single-phase steam in Combustion Engineering type steam generator U-tubes during severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Fynan, Douglas A.; Ahn, Kwang-Il, E-mail: kiahn@kaeri.re.kr

    2016-12-15

    Highlights: • Pressure drop-flow rate curves for superheated steam in U-tubes were generated. • Forward flow of hot steam is favored in the longer and taller U-tubes. • Reverse flow of cold steam is favored in short U-tubes. • Steam generator U-tube bundle geometry and tube diameter are important. • Need for correlation development for natural convention heat transfer coefficient. - Abstract: Characteristic pressure drop-flow rate curves are generated for all row numbers of the OPR1000 steam generators (SGs), representative of Combustion Engineering (CE) type SGs featuring square bend U-tubes. The pressure drop-flow rate curves are applicable to severe accident natural circulations of single-phase superheated steam during high pressure station blackout sequences with failed auxiliary feedwater and dry secondary side which are closely related to the thermally induced steam generator tube rupture event. The pressure drop-flow rate curves which determine the recirculation rate through the SG tubes are dependent on the tube bundle geometry and hydraulic diameter of the tubes. The larger CE type SGs have greater variation of tube length and height as a function of row number with forward flow of steam favored in the longer and taller high row number tubes and reverse flow favored in the short low row number tubes. Friction loss, natural convection heat transfer coefficients, and temperature differentials from the primary to secondary side are dominant parameters affecting the recirculation rate. The need for correlation development for natural convection heat transfer coefficients for external flow over tube bundles currently not modeled in system codes is discussed.

  7. THE GAS PHASE MASS METALLICITY RELATION FOR DWARF GALAXIES: DEPENDENCE ON STAR FORMATION RATE AND HI GAS MASS

    Energy Technology Data Exchange (ETDEWEB)

    Jimmy; Tran, Kim-Vy [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Saintonge, Amélie; Accurso, Gioacchino [Department of Physics and Astronomy, University College London, Gower Place, London WC1E 6BT (United Kingdom); Brough, Sarah; Oliva-Altamirano, Paola [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia)

    2015-10-20

    Using a sample of dwarf galaxies observed using the VIMOS IFU on the Very Large Telescope, we investigate the mass–metallicity relation (MZR) as a function of star formation rate (FMR{sub SFR}) as well as HI-gas mass (FMR{sub HI}). We combine our IFU data with a subsample of galaxies from the ALFALFA HI survey crossmatched to the Sloan Digital Sky Survey (SDSS) to study the FMR{sub SFR} and FMR{sub HI} across the stellar mass range 10{sup 6.6}–10{sup 8.8} M{sub ⊙}, with metallicities as low as 12 + log(O/H) = 7.67. We find the 1σ mean scatter in the MZR to be 0.05 dex. The 1σ mean scatter in the FMR{sub SFR} (0.02 dex) is significantly lower than that of the MZR. The FMR{sub SFR} is not consistent between the IFU observed galaxies and the ALFALFA/SDSS galaxies for SFRs lower than 10{sup −2.4} M{sub ⊙} yr{sup −1}, however, this could be the result of limitations of our measurements in that regime. The lowest mean scatter (0.01 dex) is found in the FMR{sub HI}. We also find that the FMR{sub HI} is consistent between the IFU observed dwarf galaxies and the ALFALFA/SDSS crossmatched sample. We introduce the fundamental metallicity luminosity counterpart to the FMR, again characterized in terms of SFR (FML{sub SFR}) and HI-gas mass (FML{sub HI}). We find that the FML{sub HI} relation is consistent between the IFU observed dwarf galaxy sample and the larger ALFALFA/SDSS sample. However, the 1σ scatter for the FML{sub HI} relation is not improved over the FMR{sub HI} scenario. This leads us to conclude that the FMR{sub HI} is the best candidate for a physically motivated fundamental metallicity relation.

  8. Rapid analysis of fungicides in tea infusions using ionic liquid immobilized fabric phase sorptive extraction with the assistance of surfactant fungicides analysis using IL-FPSE assisted with surfactant.

    Science.gov (United States)

    Yang, Miyi; Gu, Yihan; Wu, Xiaoling; Xi, Xuefei; Yang, Xiaoling; Zhou, Wenfeng; Zeng, Haozhe; Zhang, Sanbing; Lu, Runhua; Gao, Haixiang; Li, Jing

    2018-01-15

    A green, simple, inexpensive, and sensitive ionic liquid immobilized fabric phase sorptive extraction method coupled with high performance liquid chromatography was developed for rapid screening and simultaneous determination of four fungicides (azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin) residues in tea infusions. This IL modified extraction fiber is capable of extracting target analytes directly from complicated tea water matrices with the addition of surfactant. A series of extraction conditions were investigated by one-factor-at-a-time approach and orthogonal test. After a series experiments, the optimum conditions were found to be 10% [HIMIM]NTf2 as coating solution, 2min vortex time, 500μL acetonitrile as dispersive solvent and 2min desorption time. Under the above conditions, the proposed technique was applied to detect fungicides from real tea water samples with satisfactory results. Copyright © 2017. Published by Elsevier Ltd.

  9. Rapid ultra-trace analysis of sucralose in multiple-origin aqueous samples by online solid-phase extraction coupled to high-resolution mass spectrometry.

    Science.gov (United States)

    Batchu, Sudha Rani; Ramirez, Cesar E; Gardinali, Piero R

    2015-05-01

    Because of its widespread consumption and its persistence during wastewater treatment, the artificial sweetener sucralose has gained considerable interest as a proxy to detect wastewater intrusion into usable water resources. The molecular resilience of this compound dictates that coastal and oceanic waters are the final recipient of this compound with unknown effects on ecosystems. Furthermore, no suitable methodologies have been reported for routine, ultra-trace detection of sucralose in seawater as the sensitivity of traditional liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis is limited by a low yield of product ions upon collision-induced dissociation (CID). In this work, we report the development and field test of an alternative analysis tool for sucralose in environmental waters, with enough sensitivity for the proper quantitation and confirmation of this analyte in seawater. The methodology is based on automated online solid-phase extraction (SPE) and high-resolving-power orbitrap MS detection. Operating in full scan (no CID), detection of the unique isotopic pattern (100:96:31 for [M-H](-), [M-H+2](-), and [M-H+4](-), respectively) was used for ultra-trace quantitation and analyte identification. The method offers fast analysis (14 min per run) and low sample consumption (10 mL per sample) with method detection and confirmation limits (MDLs and MCLs) of 1.4 and 5.7 ng/L in seawater, respectively. The methodology involves low operating costs due to virtually no sample preparation steps or consumables. As an application example, samples were collected from 17 oceanic and estuarine sites in Broward County, FL, with varying salinity (6-40 PSU). Samples included the ocean outfall of the Southern Regional Wastewater Treatment Plant (WWTP) that serves Hollywood, FL. Sucralose was detected above MCL in 78% of the samples at concentrations ranging from 8 to 148 ng/L, with the exception of the WWTP ocean outfall (at pipe end, 28 m below the surface

  10. Nonequilibrium Phase Chemistry in High Temperature Structure Alloys

    Science.gov (United States)

    Wang, R.

    1991-01-01

    Titanium and nickel aluminides of nonequilibrium microstructures and in thin gauge thickness were identified, characterized and produced for potential high temperature applications. A high rate sputter deposition technique for rapid surveillance of the microstructures and nonequilibrium phase is demonstrated. Alloys with specific compositions were synthesized with extended solid solutions, stable dispersoids, and specific phase boundaries associated with different heat treatments. Phase stability and mechanical behavior of these nonequilibrium alloys were investigated and compared.

  11. A Rapid Centrifugation-Assisted Solid-Phase Extraction and Liquid Chromatography Method for Determination of Loureirin A and Loureirin B of Dragon's Blood Capsules in Rat Plasma and Urine After Oral Administration.

    Science.gov (United States)

    Chen, Xiaoshuang; Li, Gaofeng; Ma, Shangfang; Hu, Xujia

    2015-07-01

    A simple, sensitive and rapid centrifugation-assisted solid-phase extraction (SPE) with high-performance liquid chromatography (SPE-HPLC) method was developed for simultaneous determination of the metabolites loureirin A and loureirin B from Dragon's blood in rat plasma and urine. The development of the extraction procedure included optimization of some important extraction phases. After evaluation, the metabolites of Dragon's blood were extracted by centrifugation-assisted SPE and separated by using HPLC. This method showed good linearity (r(2) > 0.99), and in the rat plasma and urine, the recoveries were 93.1 and 95.7% for loureirin A and were 90.1 and 94.2% for loureirin B. The relative standard deviation (RSD) values of intraday and interday precision in rat plasma and urine for loureirin A were <3.84 and 2.01%, respectively. The RSD values of the intraday and interday precision in rat plasma and urine for loureirin B were below 4.25 and 5.83%, respectively. Thus, the established method is suitable for metabolism studies of loureirin A and loureirin B in rat plasma and urine. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. A rapid shaking-based ionic liquid dispersive liquid phase microextraction for the simultaneous determination of six synthetic food colourants in soft drinks, sugar- and gelatin-based confectionery by high-performance liquid chromatography.

    Science.gov (United States)

    Wu, Hao; Guo, Jing-Bo; Du, Li-Ming; Tian, Hong; Hao, Cheng-Xuan; Wang, Zhi-Feng; Wang, Jie-Yan

    2013-11-01

    A novel and simple rapid shaking-based method of ionic liquid dispersive liquid phase microextraction for the determination of six synthetic food colourants (Tartrazine, Amaranth, Sunset Yellow, Allura Red, Ponceau 4R, and Erythrosine) in soft drinks, sugar- and gelatin-based confectionery was established. High-performance liquid chromatography coupled with an ultraviolet detector was used for the determinations. The extraction procedure did not require a dispersive solvent, heat, ultrasonication, or additional chemical reagents. 1-Octyl-3-methylimidazolium tetrafluoroborate ([C8MIM][BF4]) was dispersed in an aqueous sample solution as fine droplets by manual shaking, enabling the easier migration of analytes into the ionic liquid phase. Factors such as the [C8MIM][BF4] volume, sample pH, extraction time, and centrifugation time were investigated. Under the optimum experimental conditions, the proposed method showed excellent detection sensitivity with limits of detection (signal-to-noise ratio=3) within 0.015-0.32 ng/mL. The method was also successfully used in analysing real food samples. Good spiked recoveries from 95.8%-104.5% were obtained. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Significant Treatment Effect of Bupropion in Patients With Bipolar Disorder but Similar Phase-Shifting Rate as Other Antidepressants: A Meta-Analysis Following the PRISMA Guidelines.

    Science.gov (United States)

    Li, Dian-Jeng; Tseng, Ping-Tao; Chen, Yen-Wen; Wu, Ching-Kuan; Lin, Pao-Yen

    2016-03-01

    Bupropion is widely used for treating bipolar disorder (BD), and especially those with depressive mood, based on its good treatment effect, safety profile, and lower risk of phase shifting. However, increasing evidence indicates that the safety of bupropion in BD patients may not be as good as previously thought. The aim of this study was to summarize data on the treatment effect and safety profile of bupropion in the treatment of BD via a meta-analysis. Electronic search through PubMed and ClinicalTrials.gov was performed. The inclusion criteria were: (i) studies comparing changes in disease severity before and after bupropion treatment or articles comparing the treatment effect of bupropion in BD patients with those receiving other standard treatments; (ii) articles on clinical trials in humans. The exclusion criteria were (i) case reports/series, and (ii) nonclinical trials. All effect sizes from 10 clinical trials were pooled using a random effects model. We examined the possible confounding variables using meta-regression and subgroup analysis. Bupropion significantly improved the severity of disease in BD patients (P bupropion and those who received other antidepressants. We could not perform a detailed meta-analysis of every category of antidepressant, nor could we rule out the possible confounding effect of concurrent psychotropics or include all drug side effects. Furthermore, the number of studies recruited in the meta-analysis was relatively small. Our findings reconfirm the benefits of bupropion for the treatment of bipolar depression, which are similar to those of other antidepressants. However, the rate of phase shifting with bupropion usage was not as low compared to other antidepressants as previously thought, which should serve to remind clinicians of the risk of phase shifting when prescribing bupropion to BD patients regardless of the suggestions of current clinical practice guidelines.

  14. Effects of ozone exposure on `Golden' papaya fruit by photoacoustic phase-resolved method: Physiological changes associated with carbon dioxide and ethylene emission rates during ripening

    Science.gov (United States)

    Corrêa, Savio Figueira; Mota, Leonardo; Paiva, Luisa Brito; Couto, Flávio Mota do; Silva, Marcelo Gomes da; Oliveira, Jurandi Gonçalves de; Sthel, Marcelo Silva; Vargas, Helion; Miklós, András

    2011-06-01

    This work addresses the effects of ozone activity on the physiology of `Golden' papaya fruit. Depth profile analysis of double-layer biological samples was accomplished using the phase-resolved photoacoustic spectroscopy. The feasibility of the method was demonstrated by singling out the spectra of the cuticle and the pigment layers of papaya fruit. The same approach was used to monitor changes occurring on the fruit during ripening when exposed to ozone. In addition, one has performed real time studies of fluorescence parameters and the emission rates of carbon dioxide and ethylene. Finally, the amount of pigments and the changes in waxy cuticle have been monitored. Results indicate that a fruit deliberately subjected to ozone at a level of 6 ppmv underwent ripening sooner (at least 24-48 h) than a fruit stored at ambient conditions. Moreover, ozone caused a reduction in the maximum quantum yield of photosynthetic apparatus located within the skin of papaya fruit.

  15. Modeling and simulation of non-isothermal rate-dependent damage processes in inhomogeneous materials using the phase-field approach

    Science.gov (United States)

    Radszuweit, Markus; Kraus, Christiane

    2017-07-01

    We present a continuum model that incorporates rate-dependent damage and fracture, a material order-parameter field and temperature within a phase-field approach. The models covers partial damage as well as the formation of macro-cracks. For the material order parameter we assume a Cahn Larché-type dynamics, which makes the model in particular applicable to binary alloys. We give thermodynamically consistent evolution equations resulting from a unified variational approach. Diverse coupling mechanisms can be covered within the model, such as heat dissipation, thermal-expansion-induced failure and crack deflection due to inhomogeneities. With help of an adaptive finite element code we conduct numerical experiments of different complexity in order to study the possibilities and limitations of the presented model. We furthermore include anisotropic linear elasticity in our model and investigate the effect on the crack pattern.

  16. PULSAR: A High-Repetition-Rate, High-Power, CE Phase-Locked Laser for the J.R. Macdonald Laboratory at Kansas State University

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Itzhak, Itzik [Kansas State Univ., Manhattan, KS (United States). Physics Dept. J.R. Macdonald Lab.; Carnes, Kevin D. [Kansas State Univ., Manhattan, KS (United States). Physics Dept. J.R. Macdonald Lab.; Cocke, C. Lew [Kansas State Univ., Manhattan, KS (United States). Physics Dept. J.R. Macdonald Lab.; Fehrenbach, Charles W. [Kansas State Univ., Manhattan, KS (United States). Physics Dept. J.R. Macdonald Lab.; Kumarappan, Vinod [Kansas State Univ., Manhattan, KS (United States). Physics Dept. J.R. Macdonald Lab.; Rudenko, Artem [Kansas State Univ., Manhattan, KS (United States). Physics Dept. J.R. Macdonald Lab.; Trallero, Carlos [Kansas State Univ., Manhattan, KS (United States). Physics Dept. J.R. Macdonald Lab.

    2014-05-09

    This instrumentation grant funded the development and installation of a state-of-the-art laser system to be used for the DOE funded research at the J.R. Macdonald Laboratory at Kansas State University. Specifically, we purchased a laser based on the KMLABs Red-Dragon design, which has a high repetition rate of 10-20 kHz crucial for multi-parameter coincidence measurements conducted in our lab. This laser system is carrier-envelope phase (CEP) locked and provides pulses as short as 21 fs directly from the amplifier (see details below). In addition, we have developed a pulse compression setup that provides sub 5 fs pulses and a CEP tagging capability that allows for long measurements of CEP dependent processes.

  17. Glycerol Overproduction by Engineered Saccharomyces cerevisiae Wine Yeast Strains Leads to Substantial Changes in By-Product Formation and to a Stimulation of Fermentation Rate in Stationary Phase

    Science.gov (United States)

    Remize, F.; Roustan, J. L.; Sablayrolles, J. M.; Barre, P.; Dequin, S.

    1999-01-01

    Six commercial wine yeast strains and three nonindustrial strains (two laboratory strains and one haploid strain derived from a wine yeast strain) were engineered to produce large amounts of glycerol with a lower ethanol yield. Overexpression of the GPD1 gene, encoding a glycerol-3-phosphate dehydrogenase, resulted in a 1.5- to 2.5-fold increase in glycerol production and a slight decrease in ethanol formation under conditions simulating wine fermentation. All the strains overexpressing GPD1 produced a larger amount of succinate and acetate, with marked differences in the level of these compounds between industrial and nonindustrial engineered strains. Acetoin and 2,3-butanediol formation was enhanced with significant variation between strains and in relation to the level of glycerol produced. Wine strains overproducing glycerol at moderate levels (12 to 18 g/liter) reduced acetoin almost completely to 2,3-butanediol. A lower biomass concentration was attained by GPD1-overexpressing strains, probably due to high acetaldehyde production during the growth phase. Despite the reduction in cell numbers, complete sugar exhaustion was achieved during fermentation in a sugar-rich medium. Surprisingly, the engineered wine yeast strains exhibited a significant increase in the fermentation rate in the stationary phase, which reduced the time of fermentation. PMID:9872772

  18. Rapid transitions

    Energy Technology Data Exchange (ETDEWEB)

    Hamrin, J.G.

    1980-01-01

    Solar energy programs are entering a critical transitional period as we move from the initial marketing of solar technologies into a phase of widespread commercialization. We face the dual challenge of trying to get enough solar systems in place fast enough to prove solar is a viable alternative, while trying to ensure the systems are designed and installed properly, proving the energy savings as promised. This is a period of both great opportunity and high risk as the field becomes crowded with new solar cheerleaders and supporters but seldom enough competent players. The status of existing and proposed programs for the accelerated commercialization of solar energy in California is described.

  19. Determining the effect of solid and liquid vectors on the gaseous interfacial area and oxygen transfer rates in two-phase partitioning bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Quijano, Guillermo [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y de Estudios, Avanzados del IPN (Cinvestav), Apdo. Postal 14-740, 07360 Mexico, D.F. (Mexico); Rocha-Rios, Jose [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Departamento de Ingenieria de Procesos e Hidraulica (IPH), Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 Mexico, D.F. (Mexico); Hernandez, Maria; Villaverde, Santiago [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Revah, Sergio [Departamento de Procesos y Tecnologia, Universidad Autonoma Metropolitana-Cuajimalpa, c/o IPH, UAM-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 Mexico, D.F. (Mexico); Munoz, Raul, E-mail: mutora@iq.uva.es [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Thalasso, Frederic [Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y de Estudios, Avanzados del IPN (Cinvestav), Apdo. Postal 14-740, 07360 Mexico, D.F. (Mexico)

    2010-03-15

    The effect of liquid and solid transfer vectors (silicone oil and Desmopan, respectively) on the gaseous interfacial area (a{sub g}) was evaluated in a two-phase partitioning bioreactor (TPPB) using fresh mineral salt medium and the cultivation broth of a toluene degradation culture (Pseudomonas putida DOT-T1E cultures continuously cultivated with and without silicone oil at low toluene loading rates). Higher values of a{sub g} were recorded in the presence of both silicone oil and Desmopan compared to the values obtained in the absence of a vector, regardless of the aqueous medium tested (1.6 and 3 times higher, respectively, using fresh mineral salt medium). These improvements in a{sub g} were well correlated to the oxygen mass transfer enhancements supported by the vectors (1.3 and 2.5 for liquid and solid vectors, respectively, using fresh medium). In this context, oxygen transfer rates of 2.5 g O{sub 2} L{sup -1} h{sup -1} and 1.3 g O{sub 2} L{sup -1} h{sup -1} were recorded in the presence of Desmopan and silicone oil, respectively, which are in agreement with previously reported values in literature. These results suggest that mass transfer enhancements in TPPBs might correspond to an increase in a{sub g} rather than to the establishment of a high-performance gas/vector/water transfer pathway.

  20. Effect of temperature, water-phase salt and phenolic contents on Listeria monocytogenes growth rates on cold-smoked salmon and evaluation of secondary models.

    Science.gov (United States)

    Cornu, M; Beaufort, A; Rudelle, S; Laloux, L; Bergis, H; Miconnet, N; Serot, T; Delignette-Muller, M L

    2006-02-01

    Salting and smoking are ancient processes for fish preservation. The effects of salt and phenolic smoke compounds on the growth rate of L. monocytogenes in cold-smoked salmon were investigated through physico-chemical analyses, challenge tests on surface of cold-smoked salmon at 4 degrees C and 8 degrees C, and a survey of the literature. Estimated growth rates were compared to predictions of existing secondary models, taking into account the effects of temperature, water phase salt content, phenolic content, and additional factors (e.g. pH, lactate, dissolved CO2). The secondary model proposed by Devlieghere et al. [Devlieghere, F., Geeraerd, A.H., Versyck, K.J., Vandewaetere, B., van Impe, J., Debevere, J., 2001. Growth of Listeria monocytogenes in modified atmosphere packed cooked meat products: a predictive model. Food Microbiology 18, 53-66.] and modified by Giménez and Dalgaard [Giménez, B., Dalgaard, P., 2004. Modelling and predicting the simultaneous growth of Listeria monocytogenes and spoilage micro-organisms in cold-smoked salmon. Journal of Applied Microbiology 96, 96-109.] appears appropriate. However, further research is needed to understand all effects affecting growth of L. monocytogenes in cold-smoked salmon and to obtain fully validated predictive models for use in quantitative risk assessment.