Learning Autonomy in Two or Three Steps: Linking Motivation, Authority, and Agency, with Open-ended Development

Directory of Open Access Journals (Sweden)

Tjeerd C Andringa

2013-10-01

Full Text Available In this paper we connect open-ended development, authority, agency, and motivation through 1 an analysis of the demands of existing in a complex world and 2 environmental appraisal in terms of affordance content and the complexity to select appropriate behavior. We do this by identifying a coherent core from a wide range of contributing fields. Open-ended development is a structured three-step process in which the agent first learns to master the body and then aims to make the mind into a reliable tool. Preconditioned on success in step two, step three aims to effectively co-create an optimal living environment. We argue that these steps correspond to right-left-right hemispheric dominance, where the left hemisphere specializes in control and the right hemisphere in exploration. Control (e.g., problem solving requires a closed and stable world that must be maintained by external authorities or, in step three, by the right hemisphere acting as internal authority. The three-step progression therefore corresponds to increasing autonomy and agency.Depending on how we appraise the environment, we formulate four qualitatively different motivational states: submission, control, exploration, and consolidation. Each of these four motivational states has associated reward signals of which the last three — successful control, discovery of novelty, and establishing new relations — form an open-ended development loop that, the more it is executed, helps the agent to become progressively more agentic and more able to co-create a pleasant-to-live-in world. We conclude that for autonomy to arise, the agent must exist in a (broad transition region between order and disorder in which both danger and opportunity (and with that open-ended development and motivation are defined. We conclude that a research agenda for artificial cognitive system research should include open-ended development through intrinsic motivations and ascribing more prominence to right

Programming for the Public Good: Ensuring Public Value Through the Cooperative Extension Program Development Model

Directory of Open Access Journals (Sweden)

Nancy Franz

2015-06-01

Full Text Available Effective Cooperative Extension programs produce important private and public value for individuals, families, businesses, and communities. However, the public value of Extension programming often goes unmeasured and unarticulated. Extension needs to reclaim its role as a key provider of public value for Land-Grant Universities through strong educational programs driven by infusing public value into all elements of the Extension Program Development Model. This article describes Extension’s public value movement including organizational, professional, program, and scholarship development efforts to enhance public good effectiveness articulation. Lessons learned, implications, and next steps for Extension’s public value success through a strong program development model are also shared.

Thermodynamic approach and comparison of two-step and single step DME (dimethyl ether) syntheses with carbon dioxide utilization

International Nuclear Information System (INIS)

Chen, Wei-Hsin; Hsu, Chih-Liang; Wang, Xiao-Dong

2016-01-01

DME (Dimethyl ether) synthesis from syngas with CO_2 utilization through two-step and single step processes is analyzed thermodynamically. The influences of reaction temperature, H_2/CO molar ratio, and CO_2/CO molar ratio on CO and CO_2 conversions, DME selectivity and yield, and thermal behavior are evaluated. Particular attention is paid to the comparison of the performance of DME synthesis between the two different methods. In the two-step method, the addition of CO_2 suppresses the CO conversion during methanol synthesis. An increase in CO_2/CO ratio decreases the CO_2 conversion (negative effect), but increases the total consumption amount of CO_2 (positive effect). At a given reaction temperature with H_2/CO = 4, the maximum DME yield develops at CO_2/CO = 1. In the single step method, over 98% of CO can be converted and the DME yield can be as high as 0.52 mol (mol CO)"−"1 at CO_2/CO = 2. The comparison of the single step and two-step processes indicates that the maximum CO conversion, DME selectivity, and DME yield in the former are higher than those in the latter, whereas an opposite result in the maximum CO_2 conversion is observed. These results reveal that the single step process has lower thermodynamic limitation and is a better option for DME synthesis. From CO_2 utilization point of view, the operation with low temperature, high H_2/CO ratio, and low CO_2/CO ratio results in higher CO_2 conversion, irrespective of two-step or single step DME synthesis. - Highlights: • DME (Dimethyl ether) synthesis with CO_2 utilization is analyzed thermodynamically. • Single step and two-step DME syntheses are studied and compared with each other. • CO_2 addition suppresses CO conversion in MeOH synthesis but increases MeOH yield. • The performance of the single step DME synthesis is better than that of the two-step one. • Increase CO_2/CO ratio decreases CO_2 conversion but increases CO_2 consumption amount.

Theory of two-step two-proton decays of nuclei

International Nuclear Information System (INIS)

Kadmensky, S. G.; Ivankov, Yu. V.

2014-01-01

A general theory of many-body diagonal and nondiagonal one-proton decays of spherical and deformed nuclei is developed on the basis of an approach not employing R-matrix theory in describing deep-subbarrier alpha and one-proton decays of nuclei but relying on integral formulas for the widths with respect to these decays. With the aid of this theory and by means of a diagram technique, a formalism is developed for describing two-step two-proton decays of a (Z, A) parent nucleus, which proceed as two successive time-separated one-proton decays of the parent and intermediate [(Z − 1, A − 1)] nuclei, these decays being related by the Green’s function for the intermediate nucleus, G(Z − 1, A − 1). It is shown that, upon taking into account, in this Green’s function, intermediate-nucleus states that are on- and off-shell states for the decaying system, there arise, respectively, sequential and virtual two-proton decays of parent nuclei. Expressions for the widths with respect to sequential and virtual two-proton decays from the ground and excited states of spherical and deformed nuclei and for the angular and energy distributions of emitted protons are obtained

Comparison of the Screening Tests for Gestational Diabetes Mellitus between "One-Step" and "Two-Step" Methods among Thai Pregnant Women.

Science.gov (United States)

Luewan, Suchaya; Bootchaingam, Phenphan; Tongsong, Theera

2018-01-01

To compare the prevalence and pregnancy outcomes of GDM between those screened by the "one-step" (75 gm GTT) and "two-step" (100 gm GTT) methods. A prospective study was conducted on singleton pregnancies at low or average risk of GDM. All were screened between 24 and 28 weeks, using the one-step or two-step method based on patients' preference. The primary outcome was prevalence of GDM, and secondary outcomes included birthweight, gestational age, rates of preterm birth, small/large-for-gestational age, low Apgar scores, cesarean section, and pregnancy-induced hypertension. A total of 648 women were screened: 278 in the one-step group and 370 in the two-step group. The prevalence of GDM was significantly higher in the one-step group; 32.0% versus 10.3%. Baseline characteristics and pregnancy outcomes in both groups were comparable. However, mean birthweight was significantly higher among pregnancies with GDM diagnosed by the two-step approach (3204 ± 555 versus 3009 ± 666 g; p =0.022). Likewise, the rate of large-for-date tended to be higher in the two-step group, but was not significant. The one-step approach is associated with very high prevalence of GDM among Thai population, without clear evidence of better outcomes. Thus, this approach may not be appropriate for screening in a busy antenatal care clinic like our setting or other centers in developing countries.

Comparative analysis of single-step and two-step biodiesel production using supercritical methanol on laboratory-scale

International Nuclear Information System (INIS)

Micic, Radoslav D.; Tomić, Milan D.; Kiss, Ferenc E.; Martinovic, Ferenc L.; Simikić, Mirko Ð.; Molnar, Tibor T.

2016-01-01

Highlights: • Single-step supercritical transesterification compared to the two-step process. • Two-step process: oil hydrolysis and subsequent supercritical methyl esterification. • Experiments were conducted in a laboratory-scale batch reactor. • Higher biodiesel yields in two-step process at milder reaction conditions. • Two-step process has potential to be cost-competitive with the single-step process. - Abstract: Single-step supercritical transesterification and two-step biodiesel production process consisting of oil hydrolysis and subsequent supercritical methyl esterification were studied and compared. For this purpose, comparative experiments were conducted in a laboratory-scale batch reactor and optimal reaction conditions (temperature, pressure, molar ratio and time) were determined. Results indicate that in comparison to a single-step transesterification, methyl esterification (second step of the two-step process) produces higher biodiesel yields (95 wt% vs. 91 wt%) at lower temperatures (270 °C vs. 350 °C), pressures (8 MPa vs. 12 MPa) and methanol to oil molar ratios (1:20 vs. 1:42). This can be explained by the fact that the reaction system consisting of free fatty acid (FFA) and methanol achieves supercritical condition at milder reaction conditions. Furthermore, the dissolved FFA increases the acidity of supercritical methanol and acts as an acid catalyst that increases the reaction rate. There is a direct correlation between FFA content of the product obtained in hydrolysis and biodiesel yields in methyl esterification. Therefore, the reaction parameters of hydrolysis were optimized to yield the highest FFA content at 12 MPa, 250 °C and 1:20 oil to water molar ratio. Results of direct material and energy costs comparison suggest that the process based on the two-step reaction has the potential to be cost-competitive with the process based on single-step supercritical transesterification. Higher biodiesel yields, similar or lower energy

Analysis of Approximations and Aperture Distortion for 3D Migration of Bistatic Radar Data with the Two-Step Approach

Directory of Open Access Journals (Sweden)

Zanzi Luigi

2010-01-01

Full Text Available The two-step approach is a fast algorithm for 3D migration originally introduced to process zero-offset seismic data. Its application to monostatic GPR (Ground Penetrating Radar data is straightforward. A direct extension of the algorithm for the application to bistatic radar data is possible provided that the TX-RX azimuth is constant. As for the zero-offset case, the two-step operator is exactly equivalent to the one-step 3D operator for a constant velocity medium and is an approximation of the one-step 3D operator for a medium where the velocity varies vertically. Two methods are explored for handling a heterogeneous medium; both are suitable for the application of the two-step approach, and they are compared in terms of accuracy of the final 3D operator. The aperture of the two-step operator is discussed, and a solution is proposed to optimize its shape. The analysis is of interest for any NDT application where the medium is expected to be heterogeneous, or where the antenna is not in direct contact with the medium (e.g., NDT of artworks, humanitarian demining, radar with air-launched antennas.

Two steps sintering alumina doped with niobia

International Nuclear Information System (INIS)

Gomes, L.B.; Hatzfeld, J.; Heck, M.; Pokorny, A.; Bergmann, C.P.

2014-01-01

In this work, high surface area commercial alumina was doped with niobia and sintered in two steps in order to obtain dense materials with lower processing temperatures. The powders were milled and uniaxially pressed (200 MPa). The first step of sintering took place at 1100°C for 3, 6, 9 and 12 hours, followed by the second step at 1350°C for 3 hours. The relative density, porosity and water absorption of the samples were determined by the Archimedes method. The crystalline phases were analyzed by X-ray Diffraction (XRD) and the morphology of the samples after sintering, evaluated by Scanning Electron Microscopy (SEM). The results indicate that the use of niobia combined with the two steps sintering promotes an increase in the density of the material, even at lower sintering temperatures. (author)

Uncertainty Principles on Two Step Nilpotent Lie Groups

Indian Academy of Sciences (India)

Abstract. We extend an uncertainty principle due to Cowling and Price to two step nilpotent Lie groups, which generalizes a classical theorem of Hardy. We also prove an analogue of Heisenberg inequality on two step nilpotent Lie groups.

Noise propagation in two-step series MAPK cascade.

Directory of Open Access Journals (Sweden)

Venkata Dhananjaneyulu

Full Text Available Series MAPK enzymatic cascades, ubiquitously found in signaling networks, act as signal amplifiers and play a key role in processing information during signal transduction in cells. In activated cascades, cell-to-cell variability or noise is bound to occur and thereby strongly affects the cellular response. Commonly used linearization method (LM applied to Langevin type stochastic model of the MAPK cascade fails to accurately predict intrinsic noise propagation in the cascade. We prove this by using extensive stochastic simulations for various ranges of biochemical parameters. This failure is due to the fact that the LM ignores the nonlinear effects on the noise. However, LM provides a good estimate of the extrinsic noise propagation. We show that the correct estimate of intrinsic noise propagation in signaling networks that contain at least one enzymatic step can be obtained only through stochastic simulations. Noise propagation in the cascade depends on the underlying biochemical parameters which are often unavailable. Based on a combination of global sensitivity analysis (GSA and stochastic simulations, we developed a systematic methodology to characterize noise propagation in the cascade. GSA predicts that noise propagation in MAPK cascade is sensitive to the total number of upstream enzyme molecules and the total number of molecules of the two substrates involved in the cascade. We argue that the general systematic approach proposed and demonstrated on MAPK cascade must accompany noise propagation studies in biological networks.

Two Step Synthesis of a Non-symmetric Acetylcholinesterase Reactivator

Directory of Open Access Journals (Sweden)

Vit Koleckar

2007-08-01

Full Text Available The newly developed and very promising acetylcholinesterase reactivator (E-1- (2-hydroxyiminomethylpyridinium-4-(4-hydroxyiminomethylpyridinium-but-2-ene dibromide was prepared using two different pathways via a two-step synthesis involving the appropriate (E-1-(4-bromobut-2-enyl-2- or 4-hydroxyiminomethyl-pyridinium bromides. Afterwards, purities and yields of the desired product prepared by both routes were compared. Finally, its potency to reactivate several nerve agent-inhibited acetylcholinesterases was tested.

Two-step estimation procedures for inhomogeneous shot-noise Cox processes

DEFF Research Database (Denmark)

Prokesová, Michaela; Dvorák, Jirí; Jensen, Eva B. Vedel

In the present paper we develop several two-step estimation procedures for inhomogeneous shot-noise Cox processes. The intensity function is parametrized by the inhomogeneity parameters while the pair-correlation function is parametrized by the interaction parameters. The suggested procedures...

Extension of CFD Codes Application to Two-Phase Flow Safety Problems - Phase 3

International Nuclear Information System (INIS)

Bestion, D.; Anglart, H.; Mahaffy, J.; Lucas, D.; Song, C.H.; Scheuerer, M.; Zigh, G.; Andreani, M.; Kasahara, F.; Heitsch, M.; Komen, E.; Moretti, F.; Morii, T.; Muehlbauer, P.; Smith, B.L.; Watanabe, T.

2014-11-01

. Identification of needs for additional experimental validation; - identification of a matrix of numerical benchmarks of special interest for the selected NRS problems; - establish the foundation of Best Practice Guidelines for two-phase CFD application to the selected NRS problems. This document is an extension of the first report produced by the Writing Group 3. A few NRS problems where two-phase CFD may bring real benefit are first selected to be further analysed in more detail according to some criteria. They must be high priority issues from the point of view of nuclear safety with some investigations going on and CFD investigations must have a reasonable chance to be successful in a reasonable period of time. They must address both the present generation of PWR and BWR and the Generation 3 water reactors and should possibly address all flow regimes so that they may, to some extent, envelop many other issues. A general multi-step methodology for application of two-phase CFD to nuclear safety issues is proposed. Many options are possible when using two phase CFD, for the basic model (one-fluid, two-fluid, multi-field,...), for the averaging or filtering of turbulent and two-phase scales (using RANS, LES,...), for the treatment of the interface either by an Interface Tracking Method or statistically by a volume fraction, an interfacial area equation,... The choices have to be justified after an in-depth analysis of the issue and an identification of all basic flow processes. Then closure relations have to be selected or developed for interfacial transfers, turbulent transfers and wall transfers, and a test matrix has to be established to validate all the models in a separate effect way. The method has been applied to the selected issues resulting in an updated state of the art and gaps were identified in the modelling. Available data for validation were reviewed and needs of additional data were identified. Verification tests were also identified. A few benchmarks are proposed

Comparison of single-step and two-step purified coagulants from Moringa oleifera seed for turbidity and DOC removal.

Science.gov (United States)

Sánchez-Martín, J; Ghebremichael, K; Beltrán-Heredia, J

2010-08-01

The coagulant proteins from Moringa oleifera purified with single-step and two-step ion-exchange processes were used for the coagulation of surface water from Meuse river in The Netherlands. The performances of the two purified coagulants and the crude extract were assessed in terms of turbidity and DOC removal. The results indicated that the optimum dosage of the single-step purified coagulant was more than two times higher compared to the two-step purified coagulant in terms of turbidity removal. And the residual DOC in the two-step purified coagulant was lower than in single-step purified coagulant or crude extract. (c) 2010 Elsevier Ltd. All rights reserved.

Two-step Raman spectroscopy method for tumor diagnosis

Science.gov (United States)

Zakharov, V. P.; Bratchenko, I. A.; Kozlov, S. V.; Moryatov, A. A.; Myakinin, O. O.; Artemyev, D. N.

2014-05-01

Two-step Raman spectroscopy phase method was proposed for differential diagnosis of malignant tumor in skin and lung tissue. It includes detection of malignant tumor in healthy tissue on first step with identification of concrete cancer type on the second step. Proposed phase method analyze spectral intensity alteration in 1300-1340 and 1640-1680 cm-1 Raman bands in relation to the intensity of the 1450 cm-1 band on first step, and relative differences between RS intensities for tumor area and healthy skin closely adjacent to the lesion on the second step. It was tested more than 40 ex vivo samples of lung tissue and more than 50 in vivo skin tumors. Linear Discriminant Analysis, Quadratic Discriminant Analysis and Support Vector Machine were used for tumors type classification on phase planes. It is shown that two-step phase method allows to reach 88.9% sensitivity and 87.8% specificity for malignant melanoma diagnosis (skin cancer); 100% sensitivity and 81.5% specificity for adenocarcinoma diagnosis (lung cancer); 90.9% sensitivity and 77.8% specificity for squamous cell carcinoma diagnosis (lung cancer).

Two Step Wittig/Dihydroxylation Synthetic Route to Higher Sugars

DEFF Research Database (Denmark)

Jørgensen, Morten; Madsen, Robert

1999-01-01

Higher carbon sugars are obtained by a two carbon, two step chain elongation of aldoses involving first a Wittig reaction and then an osmium tetroxide catalyzed dihydroxylation......Higher carbon sugars are obtained by a two carbon, two step chain elongation of aldoses involving first a Wittig reaction and then an osmium tetroxide catalyzed dihydroxylation...

Comparison of two-step versus four-step composite finishing/polishing disc systems: evaluation of a new two-step composite polishing disc system.

Science.gov (United States)

da Costa, Juliana B; Goncalves, Flavia; Ferracane, Jack L

2011-01-01

The purpose of this study was to evaluate surface finish and gloss of a two-step composite finishing/polishing (F/P) disc system compared with two multistep systems on five composites. Seventy-five disc-shaped composite specimens (D=10.0 mm, 2 mm thick, n=15 per composite) were made of microfill (Durafill-D), nanofill (Filtek Supreme-FS), nanohybrid (Premise-PR), and microhybrids (Filtek Z250-FZ, Esthet-EX). One side of each specimen was initially finished with a carbide bur. Five specimens of each resin composite were randomly assigned to receive full F/P by each of the disc systems: two-step (Enhance Flex NST-EF) and four-step (Sof-Lex-SL, Super-Snap-SS). Surface gloss was measured with a glossmeter and surface roughness was measured with a profilometer. Results were analyzed by two-way analysis of variance (ANOVA)/Tukey's (αgloss was noted among the three F/P systems when used with D and EX; no difference between SL and EF when used with any composite, except for FS; and no difference between SL and SS when used with any composite. SL and EF showed similar surface roughness when used on all composites, except for EX. EF and SS showed similar surface roughness on PR. SL and SS showed similar surface roughness values on every composite, except for FZ. EF was capable of providing similar gloss and surface roughness to SL on four composites evaluated but was not able to produce as glossy or as smooth a surface as SS for three of the five composites.

Time dependent theory of two-step absorption of two pulses

Energy Technology Data Exchange (ETDEWEB)

Rebane, Inna, E-mail: inna.rebane@ut.ee

2015-09-25

The time dependent theory of two step-absorption of two different light pulses with arbitrary duration in the electronic three-level model is proposed. The probability that the third level is excited at the moment t is found in depending on the time delay between pulses, the spectral widths of the pulses and the energy relaxation constants of the excited electronic levels. The time dependent perturbation theory is applied without using “doorway–window” approach. The time and spectral behavior of the spectrum using in calculations as simple as possible model is analyzed. - Highlights: • Time dependent theory of two-step absorption in the three-level model is proposed. • Two different light pulses with arbitrary duration is observed. • The time dependent perturbation theory is applied without “door–window” approach. • The time and spectral behavior of the spectra is analyzed for several cases.

Two-step membrane binding by the bacterial SRP receptor enable efficient and accurate Co-translational protein targeting.

Science.gov (United States)

Hwang Fu, Yu-Hsien; Huang, William Y C; Shen, Kuang; Groves, Jay T; Miller, Thomas; Shan, Shu-Ou

2017-07-28

The signal recognition particle (SRP) delivers ~30% of the proteome to the eukaryotic endoplasmic reticulum, or the bacterial plasma membrane. The precise mechanism by which the bacterial SRP receptor, FtsY, interacts with and is regulated at the target membrane remain unclear. Here, quantitative analysis of FtsY-lipid interactions at single-molecule resolution revealed a two-step mechanism in which FtsY initially contacts membrane via a Dynamic mode, followed by an SRP-induced conformational transition to a Stable mode that activates FtsY for downstream steps. Importantly, mutational analyses revealed extensive auto-inhibitory mechanisms that prevent free FtsY from engaging membrane in the Stable mode; an engineered FtsY pre-organized into the Stable mode led to indiscriminate targeting in vitro and disrupted FtsY function in vivo. Our results show that the two-step lipid-binding mechanism uncouples the membrane association of FtsY from its conformational activation, thus optimizing the balance between the efficiency and fidelity of co-translational protein targeting.

SU-F-J-66: Anatomy Deformation Based Comparison Between One-Step and Two-Step Optimization for Online ART

International Nuclear Information System (INIS)

Feng, Z; Yu, G; Qin, S; Li, D; Ma, C; Zhu, J; Yin, Y

2016-01-01

Purpose: This study investigated that how the quality of adapted plan was affected by inter-fractional anatomy deformation by using one-step and two-step optimization for on line adaptive radiotherapy (ART) procedure. Methods: 10 lung carcinoma patients were chosen randomly to produce IMRT plan by one-step and two-step algorithms respectively, and the prescribed dose was set as 60 Gy on the planning target volume (PTV) for all patients. To simulate inter-fractional target deformation, four specific cases were created by systematic anatomy variation; including target superior shift 0.5 cm, 0.3cm contraction, 0.3 cm expansion and 45-degree rotation. Based on these four anatomy deformation, adapted plan, regenerated plan and non-adapted plan were created to evaluate quality of adaptation. Adapted plans were generated automatically by using one-step and two-step algorithms respectively to optimize original plans, and regenerated plans were manually created by experience physicists. Non-adapted plans were produced by recalculating the dose distribution based on corresponding original plans. The deviations among these three plans were statistically analyzed by paired T-test. Results: In PTV superior shift case, adapted plans had significantly better PTV coverage by using two-step algorithm compared with one-step one, and meanwhile there was a significant difference of V95 by comparison with adapted and non-adapted plans (p=0.0025). In target contraction deformation, with almost same PTV coverage, the total lung received lower dose using one-step algorithm than two-step algorithm (p=0.0143,0.0126 for V20, Dmean respectively). In other two deformation cases, there were no significant differences observed by both two optimized algorithms. Conclusion: In geometry deformation such as target contraction, with comparable PTV coverage, one-step algorithm gave better OAR sparing than two-step algorithm. Reversely, the adaptation by using two-step algorithm had higher efficiency

SU-F-J-66: Anatomy Deformation Based Comparison Between One-Step and Two-Step Optimization for Online ART

Energy Technology Data Exchange (ETDEWEB)

Feng, Z; Yu, G; Qin, S; Li, D [Shandong Normal University, Jinan, Shandong (China); Ma, C; Zhu, J; Yin, Y [Shandong Cancer Hospital and Institute, Jinan, Shandong (China)

2016-06-15

Purpose: This study investigated that how the quality of adapted plan was affected by inter-fractional anatomy deformation by using one-step and two-step optimization for on line adaptive radiotherapy (ART) procedure. Methods: 10 lung carcinoma patients were chosen randomly to produce IMRT plan by one-step and two-step algorithms respectively, and the prescribed dose was set as 60 Gy on the planning target volume (PTV) for all patients. To simulate inter-fractional target deformation, four specific cases were created by systematic anatomy variation; including target superior shift 0.5 cm, 0.3cm contraction, 0.3 cm expansion and 45-degree rotation. Based on these four anatomy deformation, adapted plan, regenerated plan and non-adapted plan were created to evaluate quality of adaptation. Adapted plans were generated automatically by using one-step and two-step algorithms respectively to optimize original plans, and regenerated plans were manually created by experience physicists. Non-adapted plans were produced by recalculating the dose distribution based on corresponding original plans. The deviations among these three plans were statistically analyzed by paired T-test. Results: In PTV superior shift case, adapted plans had significantly better PTV coverage by using two-step algorithm compared with one-step one, and meanwhile there was a significant difference of V95 by comparison with adapted and non-adapted plans (p=0.0025). In target contraction deformation, with almost same PTV coverage, the total lung received lower dose using one-step algorithm than two-step algorithm (p=0.0143,0.0126 for V20, Dmean respectively). In other two deformation cases, there were no significant differences observed by both two optimized algorithms. Conclusion: In geometry deformation such as target contraction, with comparable PTV coverage, one-step algorithm gave better OAR sparing than two-step algorithm. Reversely, the adaptation by using two-step algorithm had higher efficiency

Do lightning positive leaders really "step"?

Science.gov (United States)

Petersen, D.

2015-12-01

It has been known for some time that positive leaders exhibit impulsive charge motion and optical emissions as they extend. However, laboratory and field observations have not produced any evidence of a process analogous to the space leader mechanism of negative leader extension. Instead, observations have suggested that the positive leader tip undergoes a continuous to intermittent series of corona streamer bursts, each burst resulting in a small forward extension of the positive leader channel. Traditionally, it has been held that lightning positive leaders extend in a continuous or quasi-continuous fashion. Lately, however, many have become concerned that this position is incongruous with observations of impulsive activity during lightning positive leader extension. It is increasingly suggested that this impulsive activity is evidence that positive leaders also undergo "stepping". There are two issues that must be addressed. The first issue concerns whether or not the physical processes underlying impulsive extension in negative and positive leaders are distinct. We argue that these processes are in fact physically distinct, and offer new high-speed video evidence to support this position. The second issue regards the proper use of the term "step" as an identifier for the impulsive forward extension of a leader. Traditional use of this term has been applied only to negative leaders, due primarily to their stronger impulsive charge motions and photographic evidence of clearly discontinuous forward progression of the luminous channel. Recently, due to the increasing understanding of the distinct "space leader" process of negative leader extension, the term "step" has increasingly come to be associated with the space leader process itself. Should this emerging association, "step" = space leader attachment, be canonized? If not, then it seems reasonable to use the term "step" to describe impulsive positive leader extension. If, however, we do wish to associate the

Two-step approach to the dynamics of coupled anharmonic oscillators

International Nuclear Information System (INIS)

Chung, N. N.; Chew, L. Y.

2009-01-01

We have further extended the two-step approach developed by Chung and Chew [N. N. Chung and L. Y. Chew, Phys. Rev. A 76, 032113 (2007)] to the solution of the quantum dynamics of general systems of N-coupled anharmonic oscillators. The idea is to employ an optimized basis set to represent the dynamical quantum states of these oscillator systems. The set is generated via the action of the optimized Bogoliubov transformed bosonic operators on the optimal squeezed vacuum product state. The procedure requires (i) applying the two-step approach to the eigendecomposition of the time evolution operator and (ii) transforming the representation of the initial state from the original to the optimal bases. We have applied the formalism to examine the dynamics of squeezing and entanglement of several anharmonic oscillator systems.

Development of F2 two-step fluorination process for non-aqueous reprocessing

International Nuclear Information System (INIS)

1976-02-01

To establish the F 2 two-step fluorination for stable and high recoveries of plutonium, the fluorination process has been studied with the simulated fuel to a FBR containing UO 2 - PuO 2 and non-radioactive fission products in the 2''phi fluid-bed. The process principle was demonstrated and the effect of FPs on fluorination of U and Pu and the possibility of reducing the Pu loss could be clarified. The feasibility of separating PuF 6 from UF 6 onto UO 2 F 2 by adsorption, was also indicated. (auth.)

Calculation of the MSD two-step process with the sudden approximation

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Shiro [Tohoku Univ., Sendai (Japan). Dept. of Physics; Kawano, Toshihiko [Kyushu Univ., Advanced Energy Engineering Science, Kasuga, Fukuoka (Japan)

2000-03-01

A calculation of the two-step process with the sudden approximation is described. The Green's function which connects the one-step matrix element to the two-step one is represented in {gamma}-space to avoid the on-energy-shell approximation. Microscopically calculated two-step cross sections are averaged together with an appropriate level density to give a two-step cross section. The calculated cross sections are compared with the experimental data, however the calculation still contains several simplifications at this moment. (author)

Incidence, risk factors, and pregnancy outcomes of gestational diabetes mellitus using one-step versus two-step diagnostic approaches: A population-based cohort study in Isfahan, Iran.

Science.gov (United States)

Hosseini, Elham; Janghorbani, Mohsen; Aminorroaya, Ashraf

2018-06-01

To study the incidence, risk factors, and pregnancy outcomes associated with gestational diabetes mellitus (GDM) diagnosed with one-step and two-step screening approaches. 1000 pregnant women who were eligible and consented to participate underwent fasting plasma glucose testing at the first prenatal visit (6-14 weeks). The women free from GDM or overt diabetes were screened at 24-28 weeks using the 50-g glucose challenge test (GCT) followed by 100-g, 3-h oral glucose tolerance test (OGTT) (two-step method). Regardless of the GCT result, all women underwent a 75-g, 2-h OGTT within one-week interval (one-step method). GDM incidence using the one-step and two-step methods was 9.3% (95% CI: 7.4-11.2) and 4.2% (95% CI: 2.9-5.5). GDM significantly increased the risk of macrosomia, gestational hypertension, preeclampsia, and cesarean section and older age and family history of diabetes significantly increased the risk of developing GDM in both approaches. In two-step method, higher pre-pregnancy body mass index and lower physical activity during pregnancy along with higher earlier cesarean section also increased significantly the risk of developing GDM. Despite a higher incidence of GDM using the one-step approach, more risk factors for and a stronger effect of GDM on adverse pregnancy outcomes were found when using the two-step approach. Longer follow-up of women with and without GDM may change the results using both approaches. Copyright © 2018 Elsevier B.V. All rights reserved.

Two-Step Oxidation of Refractory Gold Concentrates with Different Microbial Communities.

Science.gov (United States)

Wang, Guo-Hua; Xie, Jian-Ping; Li, Shou-Peng; Guo, Yu-Jie; Pan, Ying; Wu, Haiyan; Liu, Xin-Xing

2016-11-28

Bio-oxidation is an effective technology for treatment of refractory gold concentrates. However, the unsatisfactory oxidation rate and long residence time, which cause a lower cyanide leaching rate and gold recovery, are key factors that restrict the application of traditional bio-oxidation technology. In this study, the oxidation rate of refractory gold concentrates and the adaption of microorganisms were analyzed to evaluate a newly developed two-step pretreatment process, which includes a high temperature chemical oxidation step and a subsequent bio-oxidation step. The oxidation rate and recovery rate of gold were improved significantly after the two-step process. The results showed that the highest oxidation rate of sulfide sulfur could reach to 99.01 % with an extreme thermophile microbial community when the pulp density was 5%. Accordingly, the recovery rate of gold was elevated to 92.51%. Meanwhile, the results revealed that moderate thermophiles performed better than acidophilic mesophiles and extreme thermophiles, whose oxidation rates declined drastically when the pulp density was increased to 10% and 15%. The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the two-step pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample. Meanwhile, owing to the sensitivity of the microbial community under different pulp density levels, the optimization of microbial community in bio-oxidation is necessary in industry.

Coseismic Strain Steps of the 2008 Wenchuan Earthquake Indicate EW Extension of Tibetan Plateau and Increased Hazard South to Epicenter

Science.gov (United States)

Fu, G.; Shen, X.; Tang, J.; Fukuda, Y.

2008-12-01

The 2008 Wenchuan earthquake (Ms8.0) occurred at the east edge of Tibetan Plateau. It is the biggest seismic disaster in China since the 1976 Tangshan earthquake. To determine the effects of the earthquake on the deformation field of Tibetan Plateau, we collect and analyze continuing strain data of three stations before and after the earthquake in Tibetan Plateau observed by capacitance-type bore-hole strainmeters (Chi, 1985). We collect strain data in NS, EW, NE-SW and NW-NS directions at each borehole. Then we deduce the co-seismic strain steps at time point 14:28 of May 12, 2008 (at this time point the earthquake occurred) with the data before and after the earthquake using the least squares method. Our observation shows that in Tibetan Plateau significant co-seismic strain steps are accompanied with the 2008 Wenchuan earthquake. Extension in EW direction is observed at interior and north Tibetan Plateau which indicates a rapid EW extension of the whole Plateau. Field investigation shows that the 2008 Wenchuan earthquake is a manifestation of eastward growth of the Tibetan Plateau (Dong et al., 2008). Eastwards growth of the Tibetan Plateau results naturally in the extension of the Plateau in EW direction. Our co-seismic strain observation agrees well with the conclusion from surface rupture investigation. The magnitude of co-seismic strain step equals to five times of average year extensional strain rate throughout the plateau interior. Shortening in SE- NW direction is observed at the east edge of the Plateau. As hints that the eastward extension of Tibetan Plateau is resisted by Sichuan rigid basin which increases the potential earthquake hazard around the observation station, manifests the declaration from co-seismic stress changes calculation (Persons et al., 2008). Our observed co-seismic strain steps are in total lager than theoretical calculations of dislocation theories which indicate that magnitude of the great earthquake should be bigger than 7.9. Due

Two-Step Macrocycle Synthesis by Classical Ugi Reaction

NARCIS (Netherlands)

Abdelraheem, Eman M M; Khaksar, Samad; Kurpiewska, Katarzyna; Kalinowska-Tłuścik, Justyna; Shaabani, Shabnam; Dömling, Alexander

2018-01-01

The direct nonpeptidic macrocycle synthesis of α-isocyano-ω-amines via the classical Ugi four-component reaction (U-4CR) is introduced. Herein an efficient and flexible two-step procedure to complex macrocycles is reported. In the first step, the reaction between unprotected diamines and

Generalized Runge-Kutta method for two- and three-dimensional space-time diffusion equations with a variable time step

International Nuclear Information System (INIS)

Aboanber, A.E.; Hamada, Y.M.

2008-01-01

An extensive knowledge of the spatial power distribution is required for the design and analysis of different types of current-generation reactors, and that requires the development of more sophisticated theoretical methods. Therefore, the need to develop new methods for multidimensional transient reactor analysis still exists. The objective of this paper is to develop a computationally efficient numerical method for solving the multigroup, multidimensional, static and transient neutron diffusion kinetics equations. A generalized Runge-Kutta method has been developed for the numerical integration of the stiff space-time diffusion equations. The method is fourth-order accurate, using an embedded third-order solution to arrive at an estimate of the truncation error for automatic time step control. In addition, the A(α)-stability properties of the method are investigated. The analyses of two- and three-dimensional benchmark problems as well as static and transient problems, demonstrate that very accurate solutions can be obtained with assembly-sized spatial meshes. Preliminary numerical evaluations using two- and three-dimensional finite difference codes showed that the presented generalized Runge-Kutta method is highly accurate and efficient when compared with other optimized iterative numerical and conventional finite difference methods

Prostate ultrasound imaging: evaluation of a two-step scoring system in the diagnosis of prostate cancer.

Science.gov (United States)

Gao, Yong; Liao, Xin-Hong; Ma, Yan; Lu, Lu; Wei, Li-Yan; Yan, Xue

2017-12-01

This study aims to investigate the feasibility and performance of a two-step scoring system of ultrasound imaging in the diagnosis of prostate cancer. 75 patients with 888 consecutive histopathologically verified lesions were included in this study. Step 1, an initial 5-point scoring system was developed based on conventional transrectal ultrasound (TRUS). Step 2, a final scoring system was evaluated according to contrast-enhanced transrectal ultrasound (CE-TRUS). Each lesion was evaluated using the two-step scoring system (step 1 + step 2) and compared with only using conventional TRUS (step 1). 888 lesions were histologically verified: 315 of them were prostate cancer from 46 patients and 573 were benign prostatic hypertrophy (BPH) from 29 patients. According to the two-step scoring system, 284 lesions were upgraded and 130 lesions were downgraded from step 1 to step 2 (this means using step 2 to assess the results by step 1). However, 96 cases were improperly upgraded after step 2 and 48 malignant lesions were still missed after step 2 as score-1. For the two-step scoring system, the sensitivity, specificity, and accuracy were 84.7%, 83.2%, and 83.7%, respectively, versus 22.8%, 96.6%, and 70.4%, respectively, for conventional TRUS. The area under the ROC curve (AUC) for lesion diagnosis was 0.799-0.952 for the two-step scoring system, versus 0.479-0.712 for conventional TRUS. The difference in the diagnostic accuracy of the two-step scoring system and conventional TRUS was statistically significant (Pstep scoring system was straightforward to use and achieved a considerably accurate diagnostic performance for prostate cancer. The application of the two-step scoring system for prostate cancer is promising.

A step-by-step development of radioactive waste management strategy

International Nuclear Information System (INIS)

Lytsy, Tero; Yla-Mella, Mia

2013-01-01

Fennovoima is Finland's third nuclear power company founded in 2007. Fennovoima will build a new nuclear power plant, Hanhikivi 1, in Pyhajoki municipality located in Northern Finland. Currently Fennovoima is evaluating bids from reactor suppliers. Originally two suppliers, AREVA and Toshiba Heavy Industries were invited to bid for the plant but later also a bid from Rosatom were invited. The plant supplier will be selected in 2013. Platom is a Finnish company with extensive experience in radioactive waste management. In the beginning of 2008, Platom was assigned by Fennovoima as radioactive waste management consultant and to develop radioactive waste management strategy and to support Fennovoima in negotiations with plant suppliers in waste management aspects. Since Fennovoima has started, there have been some changes to the regulatory requirements which had to be taken into account while developing the strategy. One important change is due to the Government Degree 27.11.2008/736 which establishes a new waste category of very low-level waste following international development and the 'new' IAEA waste classification. Other important change was introduced by the change 342/2008 to the Nuclear Energy Act allowing some nuclear waste to be delivered to another country for treatment. These and many more requirements had to be considered when developing the strategy. Early work by Platom was mostly done to support development of application for Decision-in-Principle. This was the first important licensing step for Fennovoima. Work started with studies and plans which were used by Fennovoima to gather the know-how required to draw up the application. Descriptions of waste streams and waste management technologies were developed as well as preliminary waste inventories and studies for final disposal, including preliminary dimensioning of the repository facilities. Based on these plans nuclear regulator's preliminary safety assessment was performed. The

One step versus two step approach for gestational diabetes screening: systematic review and meta-analysis of the randomized trials.

Science.gov (United States)

Saccone, Gabriele; Caissutti, Claudia; Khalifeh, Adeeb; Meltzer, Sara; Scifres, Christina; Simhan, Hyagriv N; Kelekci, Sefa; Sevket, Osman; Berghella, Vincenzo

2017-12-03

To compare both the prevalence of gestational diabetes mellitus (GDM) as well as maternal and neonatal outcomes by either the one-step or the two-step approaches. Electronic databases were searched from their inception until June 2017. We included all randomized controlled trials (RCTs) comparing the one-step with the two-step approaches for the screening and diagnosis of GDM. The primary outcome was the incidence of GDM. Three RCTs (n = 2333 participants) were included in the meta-analysis. 910 were randomized to the one step approach (75 g, 2 hrs), and 1423 to the two step approach. No significant difference in the incidence of GDM was found comparing the one step versus the two step approaches (8.4 versus 4.3%; relative risk (RR) 1.64, 95%CI 0.77-3.48). Women screened with the one step approach had a significantly lower risk of preterm birth (PTB) (3.7 versus 7.6%; RR 0.49, 95%CI 0.27-0.88), cesarean delivery (16.3 versus 22.0%; RR 0.74, 95%CI 0.56-0.99), macrosomia (2.9 versus 6.9%; RR 0.43, 95%CI 0.22-0.82), neonatal hypoglycemia (1.7 versus 4.5%; RR 0.38, 95%CI 0.16-0.90), and admission to neonatal intensive care unit (NICU) (4.4 versus 9.0%; RR 0.49, 95%CI 0.29-0.84), compared to those randomized to screening with the two step approach. The one and the two step approaches were not associated with a significant difference in the incidence of GDM. However, the one step approach was associated with better maternal and perinatal outcomes.

Two-Step Incision for Periarterial Sympathectomy of the Hand

Directory of Open Access Journals (Sweden)

Seung Bae Jeon

2015-11-01

Full Text Available BackgroundSurgical scars on the palmar surface of the hand may lead to functional and also aesthetic and psychological consequences. The objective of this study was to introduce a new incision technique for periarterial sympathectomy of the hand and to compare the results of the new two-step incision technique with those of a Koman incision by using an objective questionnaire.MethodsA total of 40 patients (17 men and 23 women with intractable Raynaud's disease or syndrome underwent surgery in our hospital, conducted by a single surgeon, between January 2008 and January 2013. Patients who had undergone extended sympathectomy or vessel graft were excluded. Clinical evaluation of postoperative scars was performed in both groups one year after surgery using the patient and observer scar assessment scale (POSAS and the Wake Forest University rating scale.ResultsThe total patient score was 8.59 (range, 6-15 in the two-step incision group and 9.62 (range, 7-18 in the Koman incision group. A significant difference was found between the groups in the total PS score (P-value=0.034 but not in the total observer score. Our analysis found no significant difference in preoperative and postoperative Wake Forest University rating scale scores between the two-step and Koman incision groups. The time required for recovery prior to returning to work after surgery was shorter in the two-step incision group, with a mean of 29.48 days in the two-step incision group and 34.15 days in the Koman incision group (P=0.03.ConclusionsCompared to the Koman incision, the new two-step incision technique provides better aesthetic results, similar symptom improvement, and a reduction in the recovery time required before returning to work. Furthermore, this incision allows the surgeon to access a wide surgical field and a sufficient exposure of anatomical structures.

SPAR-H Step-by-Step Guidance

Energy Technology Data Exchange (ETDEWEB)

W. J. Galyean; A. M. Whaley; D. L. Kelly; R. L. Boring

2011-05-01

This guide provides step-by-step guidance on the use of the SPAR-H method for quantifying Human Failure Events (HFEs). This guide is intended to be used with the worksheets provided in: 'The SPAR-H Human Reliability Analysis Method,' NUREG/CR-6883, dated August 2005. Each step in the process of producing a Human Error Probability (HEP) is discussed. These steps are: Step-1, Categorizing the HFE as Diagnosis and/or Action; Step-2, Rate the Performance Shaping Factors; Step-3, Calculate PSF-Modified HEP; Step-4, Accounting for Dependence, and; Step-5, Minimum Value Cutoff. The discussions on dependence are extensive and include an appendix that describes insights obtained from the psychology literature.

SPAR-H Step-by-Step Guidance

International Nuclear Information System (INIS)

Galyean, W.J.; Whaley, A.M.; Kelly, D.L.; Boring, R.L.

2011-01-01

This guide provides step-by-step guidance on the use of the SPAR-H method for quantifying Human Failure Events (HFEs). This guide is intended to be used with the worksheets provided in: 'The SPAR-H Human Reliability Analysis Method,' NUREG/CR-6883, dated August 2005. Each step in the process of producing a Human Error Probability (HEP) is discussed. These steps are: Step-1, Categorizing the HFE as Diagnosis and/or Action; Step-2, Rate the Performance Shaping Factors; Step-3, Calculate PSF-Modified HEP; Step-4, Accounting for Dependence, and; Step-5, Minimum Value Cutoff. The discussions on dependence are extensive and include an appendix that describes insights obtained from the psychology literature.

Two step culture for production of recombinant herpes simplex virus ...

African Journals Online (AJOL)

Herpes simplex virus type 2 (HSV-2) was the major cause of genital herpes in humans. The HSV-2 glycoprotein D (gD2) had been proved to be a potentially effective vaccine for treatment of genital herpes. The present study was to develop a two step culture to express the recombinant gD2 protein using the immobilized ...

Study of CdTe quantum dots grown using a two-step annealing method

Science.gov (United States)

Sharma, Kriti; Pandey, Praveen K.; Nagpal, Swati; Bhatnagar, P. K.; Mathur, P. C.

2006-02-01

High size dispersion, large average radius of quantum dot and low-volume ratio has been a major hurdle in the development of quantum dot based devices. In the present paper, we have grown CdTe quantum dots in a borosilicate glass matrix using a two-step annealing method. Results of optical characterization and the theoretical model of absorption spectra have shown that quantum dots grown using two-step annealing have lower average radius, lesser size dispersion, higher volume ratio and higher decrease in bulk free energy as compared to quantum dots grown conventionally.

A Two-Step Approach for Analysis of Nonignorable Missing Outcomes in Longitudinal Regression: an Application to Upstate KIDS Study.

Science.gov (United States)

Liu, Danping; Yeung, Edwina H; McLain, Alexander C; Xie, Yunlong; Buck Louis, Germaine M; Sundaram, Rajeshwari

2017-09-01

Imperfect follow-up in longitudinal studies commonly leads to missing outcome data that can potentially bias the inference when the missingness is nonignorable; that is, the propensity of missingness depends on missing values in the data. In the Upstate KIDS Study, we seek to determine if the missingness of child development outcomes is nonignorable, and how a simple model assuming ignorable missingness would compare with more complicated models for a nonignorable mechanism. To correct for nonignorable missingness, the shared random effects model (SREM) jointly models the outcome and the missing mechanism. However, the computational complexity and lack of software packages has limited its practical applications. This paper proposes a novel two-step approach to handle nonignorable missing outcomes in generalized linear mixed models. We first analyse the missing mechanism with a generalized linear mixed model and predict values of the random effects; then, the outcome model is fitted adjusting for the predicted random effects to account for heterogeneity in the missingness propensity. Extensive simulation studies suggest that the proposed method is a reliable approximation to SREM, with a much faster computation. The nonignorability of missing data in the Upstate KIDS Study is estimated to be mild to moderate, and the analyses using the two-step approach or SREM are similar to the model assuming ignorable missingness. The two-step approach is a computationally straightforward method that can be conducted as sensitivity analyses in longitudinal studies to examine violations to the ignorable missingness assumption and the implications relative to health outcomes. © 2017 John Wiley & Sons Ltd.

Agricultural extension, research, and development for increased ...

African Journals Online (AJOL)

The challenges of food security and agricultural development in South Africa cannot simply be solved by limiting extension and research development to the public sector. However, if shortcomings arise in the public sector while addressing extension, research and development, the potential involvement of the private sector ...

Baryogenesis in the two doublet and inert singlet extension of the Standard Model

Energy Technology Data Exchange (ETDEWEB)

Alanne, Tommi [CP" 3-Origins, University of Southern Denmark,Campusvej 55, DK-5230 Odense M (Denmark); Kainulainen, Kimmo [Department of Physics, University of Jyväskylä,P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland); Helsinki Institute of Physics, University of Helsinki,P.O. Box 64, FI-00014 Helsinki (Finland); Tuominen, Kimmo [Department of Physics, University of Helsinki,P.O. Box 64, FI-00014 Helsinki (Finland); Helsinki Institute of Physics, University of Helsinki,P.O. Box 64, FI-00014 Helsinki (Finland); Vaskonen, Ville [Department of Physics, University of Jyväskylä,P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland); Helsinki Institute of Physics, University of Helsinki,P.O. Box 64, FI-00014 Helsinki (Finland)

2016-08-25

We investigate an extension of the Standard Model containing two Higgs doublets and a singlet scalar field (2HDSM). We show that the model can have a strongly first-order phase transition and give rise to the observed baryon asymmetry of the Universe, consistent with all experimental constraints. In particular, the constraints from the electron and neutron electric dipole moments are less constraining here than in pure two-Higgs-doublet model (2HDM). The two-step, first-order transition in 2HDSM, induced by the singlet field, may lead to strong supercooling and low nucleation temperatures in comparison with the critical temperature, T{sub n}≪T{sub c}, which can significantly alter the usual phase-transition pattern in 2HD models with T{sub n}≈T{sub c}. Furthermore, the singlet field can be the dark matter particle. However, in models with a strong first-order transition its abundance is typically but a thousandth of the observed dark matter abundance.

Two General Extension Algorithms of Latin Hypercube Sampling

Directory of Open Access Journals (Sweden)

Zhi-zhao Liu

2015-01-01

Full Text Available For reserving original sampling points to reduce the simulation runs, two general extension algorithms of Latin Hypercube Sampling (LHS are proposed. The extension algorithms start with an original LHS of size m and construct a new LHS of size m+n that contains the original points as many as possible. In order to get a strict LHS of larger size, some original points might be deleted. The relationship of original sampling points in the new LHS structure is shown by a simple undirected acyclic graph. The basic general extension algorithm is proposed to reserve the most original points, but it costs too much time. Therefore, a general extension algorithm based on greedy algorithm is proposed to reduce the extension time, which cannot guarantee to contain the most original points. These algorithms are illustrated by an example and applied to evaluating the sample means to demonstrate the effectiveness.

Two-step variable selection in quantile regression models

Directory of Open Access Journals (Sweden)

FAN Yali

2015-06-01

Full Text Available We propose a two-step variable selection procedure for high dimensional quantile regressions, in which the dimension of the covariates, pn is much larger than the sample size n. In the first step, we perform ℓ1 penalty, and we demonstrate that the first step penalized estimator with the LASSO penalty can reduce the model from an ultra-high dimensional to a model whose size has the same order as that of the true model, and the selected model can cover the true model. The second step excludes the remained irrelevant covariates by applying the adaptive LASSO penalty to the reduced model obtained from the first step. Under some regularity conditions, we show that our procedure enjoys the model selection consistency. We conduct a simulation study and a real data analysis to evaluate the finite sample performance of the proposed approach.

Control Software for Piezo Stepping Actuators

Science.gov (United States)

Shields, Joel F.

2013-01-01

A control system has been developed for the Space Interferometer Mission (SIM) piezo stepping actuator. Piezo stepping actuators are novel because they offer extreme dynamic range (centimeter stroke with nanometer resolution) with power, thermal, mass, and volume advantages over existing motorized actuation technology. These advantages come with the added benefit of greatly reduced complexity in the support electronics. The piezo stepping actuator consists of three fully redundant sets of piezoelectric transducers (PZTs), two sets of brake PZTs, and one set of extension PZTs. These PZTs are used to grasp and move a runner attached to the optic to be moved. By proper cycling of the two brake and extension PZTs, both forward and backward moves of the runner can be achieved. Each brake can be configured for either a power-on or power-off state. For SIM, the brakes and gate of the mechanism are configured in such a manner that, at the end of the step, the actuator is in a parked or power-off state. The control software uses asynchronous sampling of an optical encoder to monitor the position of the runner. These samples are timed to coincide with the end of the previous move, which may consist of a variable number of steps. This sampling technique linearizes the device by avoiding input saturation of the actuator and makes latencies of the plant vanish. The software also estimates, in real time, the scale factor of the device and a disturbance caused by cycling of the brakes. These estimates are used to actively cancel the brake disturbance. The control system also includes feedback and feedforward elements that regulate the position of the runner to a given reference position. Convergence time for smalland medium-sized reference positions (less than 200 microns) to within 10 nanometers can be achieved in under 10 seconds. Convergence times for large moves (greater than 1 millimeter) are limited by the step rate.

Testing a stepped care model for binge-eating disorder: a two-step randomized controlled trial.

Science.gov (United States)

Tasca, Giorgio A; Koszycki, Diana; Brugnera, Agostino; Chyurlia, Livia; Hammond, Nicole; Francis, Kylie; Ritchie, Kerri; Ivanova, Iryna; Proulx, Genevieve; Wilson, Brian; Beaulac, Julie; Bissada, Hany; Beasley, Erin; Mcquaid, Nancy; Grenon, Renee; Fortin-Langelier, Benjamin; Compare, Angelo; Balfour, Louise

2018-05-24

A stepped care approach involves patients first receiving low-intensity treatment followed by higher intensity treatment. This two-step randomized controlled trial investigated the efficacy of a sequential stepped care approach for the psychological treatment of binge-eating disorder (BED). In the first step, all participants with BED (n = 135) received unguided self-help (USH) based on a cognitive-behavioral therapy model. In the second step, participants who remained in the trial were randomized either to 16 weeks of group psychodynamic-interpersonal psychotherapy (GPIP) (n = 39) or to a no-treatment control condition (n = 46). Outcomes were assessed for USH in step 1, and then for step 2 up to 6-months post-treatment using multilevel regression slope discontinuity models. In the first step, USH resulted in large and statistically significant reductions in the frequency of binge eating. Statistically significant moderate to large reductions in eating disorder cognitions were also noted. In the second step, there was no difference in change in frequency of binge eating between GPIP and the control condition. Compared with controls, GPIP resulted in significant and large improvement in attachment avoidance and interpersonal problems. The findings indicated that a second step of a stepped care approach did not significantly reduce binge-eating symptoms beyond the effects of USH alone. The study provided some evidence for the second step potentially to reduce factors known to maintain binge eating in the long run, such as attachment avoidance and interpersonal problems.

Reactor vessel assessment and the development of a reactor vessel life extension program for Calvert Cliffs Units One and Two

International Nuclear Information System (INIS)

Montgomery, B.; Hijeck, P.J.

1988-01-01

A study has been undertaken to provide a general assessment of the life extension capabilities for the Calvert Cliffs Units One and Two reactor pressure vessels. The purpose of the study is to assess the general life extension capabilities for the Calvert Cliffs reactor pressure vessels based upon an extension and variation of the Surry pilot plant life extension study. This assessment provided a detailed reactor vessel surveillance program for plant life extension along with a hierarchy of specific tasks necessary for attaining maximum useful life. The assessment identified a number of critical issues which may impact life attainment and extension along with potential solutions to address these issues to ensure the life extension option is not precluded

Two-step rocket engine bipropellant valve concept

Science.gov (United States)

Capps, J. E.; Ferguson, R. E.; Pohl, H. O.

1969-01-01

Initiating combustion of altitude control rocket engines in a precombustion chamber of ductile material reduces high pressure surges generated by hypergolic propellants. Two-step bipropellant valve concepts control initial propellant flow into precombustion chamber and subsequent full flow into main chamber.

Advanced Laser Architecture for Two-Step Laser Tandem Mass Spectrometer

Science.gov (United States)

Fahey, Molly E.; Li, Steven X.; Yu, Anthony W.; Getty, Stephanie A.

2016-01-01

Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. These missions require advanced instrument techniques to fully and unambiguously characterize the composition of surface and dust materials. Laser desorptionionization mass spectrometry (LDMS) is an emerging instrument technology for in situ mass analysis of non-volatile sample composition. A recent Goddard LDMS advancement is the two-step laser tandem mass spectrometer (L2MS) instrument to address the need for future flight instrumentation to deconvolve complex organic signatures. The L2MS prototype uses a resonance enhanced multi-photon laser ionization mechanism to selectively detect aromatic species from a more complex sample. By neglecting the aliphatic and inorganic mineral signatures in the two-step mass spectrum, the L2MS approach can provide both mass assignments and clues to structural information for an in situ investigation of non-volatile sample composition. In this paper we will describe our development effort on a new laser architecture that is based on the previously flown Lunar Orbiter Laser Altimeter (LOLA) laser transmitter for the L2MS instrument. The laser provides two discrete midinfrared wavelengths (2.8 m and 3.4 m) using monolithic optical parametric oscillators and ultraviolet (UV) wavelength (266 nm) on a single laser bench with a straightforward development path toward flight readiness.

Two-step sintering of ultrafine-grained barium cerate proton conducting ceramics

International Nuclear Information System (INIS)

Wang, Siwei; Zhang, Lei; Zhang, Lingling; Brinkman, Kyle; Chen, Fanglin

2013-01-01

Ultra-fine grained dense BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3−δ (BZCYYb) ceramics have been successfully prepared via a two-step sintering method. Co-precipitation method has been adopted to prepare nano-sized BZCYYb precursors with an average particle size of 30 nm. By controlling the sintering profile, an average grain size of 184 nm was obtained for dense BZCYYb ceramics via the two-step sintering method, compared to 445 nm for the conventional sintered samples. The two-step sintered BZCYYb samples showed less impurity and an enhanced electrical conductivity compared with the conventional sintered ones. Further, the two-step sintering method was applied to fabricate anode supported solid oxide fuel cells (SOFCs) using BZCYYb as the electrolyte, resulting in dense ultrafine-grained electrolyte membranes and porous anode substrates with fine particles. Due to the reduced ohmic as well as polarization resistances, the maximum power output of the cells fabricated from the two-step sintering method reached 349 mW m −2 at 700 °C, significantly improved from 172 mW cm −2 for the conventional sintered cells, suggesting that two-step sintering method is very promising for optimizing the microstructure and thus enhancing the electrochemical performances for barium cerate based proton-conducting SOFCs.

Maximizing Efficiency in Two-step Solar-thermochemical Fuel Production

Energy Technology Data Exchange (ETDEWEB)

Ermanoski, I. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2015-05-01

Widespread solar fuel production depends on its economic viability, largely driven by the solar-to-fuel conversion efficiency. In this paper, the material and energy requirements in two-step solar-thermochemical cycles are considered.The need for advanced redox active materials is demonstrated, by considering the oxide mass flow requirements at a large scale. Two approaches are also identified for maximizing the efficiency: optimizing reaction temperatures, and minimizing the pressure in the thermal reduction step by staged thermal reduction. The results show that each approach individually, and especially the two in conjunction, result in significant efficiency gains.

A Two-Step Approach to Uncertainty Quantification of Core Simulators

Directory of Open Access Journals (Sweden)

Artem Yankov

2012-01-01

Full Text Available For the multiple sources of error introduced into the standard computational regime for simulating reactor cores, rigorous uncertainty analysis methods are available primarily to quantify the effects of cross section uncertainties. Two methods for propagating cross section uncertainties through core simulators are the XSUSA statistical approach and the “two-step” method. The XSUSA approach, which is based on the SUSA code package, is fundamentally a stochastic sampling method. Alternatively, the two-step method utilizes generalized perturbation theory in the first step and stochastic sampling in the second step. The consistency of these two methods in quantifying uncertainties in the multiplication factor and in the core power distribution was examined in the framework of phase I-3 of the OECD Uncertainty Analysis in Modeling benchmark. With the Three Mile Island Unit 1 core as a base model for analysis, the XSUSA and two-step methods were applied with certain limitations, and the results were compared to those produced by other stochastic sampling-based codes. Based on the uncertainty analysis results, conclusions were drawn as to the method that is currently more viable for computing uncertainties in burnup and transient calculations.

Two-phase 1D+1D model of a DMFC: development and validation on extensive operating conditions range

Energy Technology Data Exchange (ETDEWEB)

Casalegno, A.; Marchesi, R.; Parenti, D. [Dipartimento di Energetica, Politecnico di Milano (Italy)

2008-02-15

A two-phase 1D+1D model of a direct methanol fuel cell (DMFC) is developed, considering overall mass balance, methanol transport in gas phase through anode diffusion layer, methanol and water crossover. The model is quantitatively validated on an extensive range of operating conditions, 24 polarisation curves. The model accurately reproduces DMFC performance in the validation range and, outside this, it is able to predict values under feasible operating conditions. Finally, the estimations of methanol crossover flux are qualitatively and quantitatively similar to experimental measures and the main local quantities' trends are coherent with results obtained with more complex models. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

A new two-step tuning procedure for a photocathode gun

International Nuclear Information System (INIS)

Lal, Shankar; Pant, K.K.; Krishnagopal, S.

2008-01-01

An important aspect of the development of multi-cell RF accelerating structures is tuning the resonant frequency f of the operating mode, field balance e b , and waveguide to cavity coupling coefficient β to the desired values. Earlier theoretical analyses have not been able to predict all three parameters simultaneously for a coupled-cavity system. We have developed a generalized circuit analysis to predict f, e b , and β of a coupled structure, based on the RF properties of the individual, uncoupled, cells. This has been used to develop a simplified two-step tuning procedure to tune a BNL/SLAC/UCLA type 1.6 cell S-band photocathode gun by varying RF properties of individual half and full cells, which are easily measurable. This procedure has been validated by tuning two true-to-scale prototypes made of aluminum and ETP copper to the desired values of the RF parameters

A two-step Hilbert transform method for 2D image reconstruction

International Nuclear Information System (INIS)

Noo, Frederic; Clackdoyle, Rolf; Pack, Jed D

2004-01-01

The paper describes a new accurate two-dimensional (2D) image reconstruction method consisting of two steps. In the first step, the backprojected image is formed after taking the derivative of the parallel projection data. In the second step, a Hilbert filtering is applied along certain lines in the differentiated backprojection (DBP) image. Formulae for performing the DBP step in fan-beam geometry are also presented. The advantage of this two-step Hilbert transform approach is that in certain situations, regions of interest (ROIs) can be reconstructed from truncated projection data. Simulation results are presented that illustrate very similar reconstructed image quality using the new method compared to standard filtered backprojection, and that show the capability to correctly handle truncated projections. In particular, a simulation is presented of a wide patient whose projections are truncated laterally yet for which highly accurate ROI reconstruction is obtained

A two-step method for rapid characterization of electroosmotic flows in capillary electrophoresis.

Science.gov (United States)

Zhang, Wenjing; He, Muyi; Yuan, Tao; Xu, Wei

2017-12-01

The measurement of electroosmotic flow (EOF) is important in a capillary electrophoresis (CE) experiment in terms of performance optimization and stability improvement. Although several methods exist, there are demanding needs to accurately characterize ultra-low electroosmotic flow rates (EOF rates), such as in coated capillaries used in protein separations. In this work, a new method, called the two-step method, was developed to accurately and rapidly measure EOF rates in a capillary, especially for measuring the ultra-low EOF rates in coated capillaries. In this two-step method, the EOF rates were calculated by measuring the migration time difference of a neutral marker in two consecutive experiments, in which a pressure driven was introduced to accelerate the migration and the DC voltage was reversed to switch the EOF direction. Uncoated capillaries were first characterized by both this two-step method and a conventional method to confirm the validity of this new method. Then this new method was applied in the study of coated capillaries. Results show that this new method is not only fast in speed, but also better in accuracy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of an omental pedicle extension technique in the dog.

Science.gov (United States)

Ross, W E; Pardo, A D

1993-01-01

A two-step omental pedicle extension technique was performed on 10 dogs. Step 1 of the pedicle extension involved release of the dorsal leaf of the omentum from its pancreatic attachment, whereas step 2 consisted of an inverse L-shaped incision to double the length of the pedicle. The pedicle dimensions were measured and the distance reached when extended toward the hind limb, forelimb, and the muzzle recorded after each stage of the procedure. The vascular patency of the pedicle was determined by intravenous injection of fluorescein dye after the second stage of omental extension. Mean pedicle lengths were 44.5 cm with the first stage of extension and 82.0 cm after full extension. The mean width at the caudal extent of the pedicles after dorsal and full extension was 30.4 cm and 17.2 cm, respectively. Eight of the 10 pedicles were patent after full extension. The fully extended omental pedicles reached and, in most cases, extended beyond the distal extremities and the muzzle. The findings in this study suggest that the canine omentum can be extended to any part of the body without being detached from its vascular supply.

Performance enhancement of a heterojunction bipolar transistor (HBT) by two-step passivation

International Nuclear Information System (INIS)

Fu, S.-I.; Lai, P.-H.; Tsai, Y.-Y.; Hung, C.-W.; Yen, C.-H.; Cheng, S.-Y.; Liu, W.-C.

2006-01-01

An interesting two-step passivation (with ledge structure and sulphide based chemical treatment) on base surface, for the first time, is demonstrated to study the temperature-dependent DC characteristics and noise performance of an InGaP/GaAs heterojunction bipolar transistor (HBT). Improved transistor behaviors on maximum current gain β max , offset voltage ΔV CE , and emitter size effect are obtained by using the two-step passivation. Moreover, the device with the two-step passivation exhibits relatively temperature-independent and improved thermal stable performances as the temperature is increased. Therefore, the two-step passivationed device can be used for high-temperature and low-power electronics applications

Two-Step Classification of Unemployed People in the Czech Republic

OpenAIRE

Zdeněk Šulc; Marina Stecenková; Jiří Vild

2015-01-01

The paper analyzes structure and behavior of unemployed people in the Czech Republic by means of latent class analysis (LCA) and CHAID analysis where the output of LCA serves as the input for CHAID. The unemployed are classified in two steps; for each step different characteristics are used. In the first step, respondents are split into latent classes according to their answers to questions concerning ways of searching for a new job. In the second step, CHAID analysis is performed with result...

A simple and accurate two-step long DNA sequences synthesis strategy to improve heterologous gene expression in pichia.

Directory of Open Access Journals (Sweden)

Jiang-Ke Yang

Full Text Available In vitro gene chemical synthesis is a powerful tool to improve the expression of gene in heterologous system. In this study, a two-step gene synthesis strategy that combines an assembly PCR and an overlap extension PCR (AOE was developed. In this strategy, the chemically synthesized oligonucleotides were assembled into several 200-500 bp fragments with 20-25 bp overlap at each end by assembly PCR, and then an overlap extension PCR was conducted to assemble all these fragments into a full length DNA sequence. Using this method, we de novo designed and optimized the codon of Rhizopus oryzae lipase gene ROL (810 bp and Aspergillus niger phytase gene phyA (1404 bp. Compared with the original ROL gene and phyA gene, the codon-optimized genes expressed at a significantly higher level in yeasts after methanol induction. We believe this AOE method to be of special interest as it is simple, accurate and has no limitation with respect to the size of the gene to be synthesized. Combined with de novo design, this method allows the rapid synthesis of a gene optimized for expression in the system of choice and production of sufficient biological material for molecular characterization and biotechnological application.

A Two-Step Approach for Analytical Optimal Hedging with Two Triggers

Directory of Open Access Journals (Sweden)

Tiesong Hu

2016-02-01

Full Text Available Hedging is widely used to mitigate severe water shortages in the operation of reservoirs during droughts. Rationing is usually instituted with one hedging policy, which is based only on one trigger, i.e., initial storage level or current water availability. It may perform poorly in balancing the benefits of a release during the current period versus those of carryover storage during future droughts. This study proposes a novel hedging rule to improve the efficiency of a reservoir operated to supply water, in which, based on two triggers, hedging is initiated with three different hedging sub-rules through a two-step approach. In the first step, the sub-rule is triggered based on the relationship between the initial reservoir storage level and the level of the target rule curve or the firm rule curve at the end of the current period. This step is mainly concerned with increasing the water level or not in the current period. Hedging is then triggered under the sub-rule based on current water availability in the second step, in which the trigger implicitly considers both initial and ending reservoir storage levels in the current period. Moreover, the amount of hedging is analytically derived based on the Karush–Kuhn–Tucker (KKT conditions. In addition, the hedging parameters are optimized using the improved particle swarm optimization (IPSO algorithm coupled with a rule-based simulation. A single water-supply reservoir located in Hubei Province in central China is selected as a case study. The operation results show that the proposed rule is reasonable and significantly improves the reservoir operation performance for both long-term and critical periods relative to other operation policies, such as the standard operating policy (SOP and the most commonly used hedging rules.

Two-level image authentication by two-step phase-shifting interferometry and compressive sensing

Science.gov (United States)

Zhang, Xue; Meng, Xiangfeng; Yin, Yongkai; Yang, Xiulun; Wang, Yurong; Li, Xianye; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

2018-01-01

A two-level image authentication method is proposed; the method is based on two-step phase-shifting interferometry, double random phase encoding, and compressive sensing (CS) theory, by which the certification image can be encoded into two interferograms. Through discrete wavelet transform (DWT), sparseness processing, Arnold transform, and data compression, two compressed signals can be generated and delivered to two different participants of the authentication system. Only the participant who possesses the first compressed signal attempts to pass the low-level authentication. The application of Orthogonal Match Pursuit CS algorithm reconstruction, inverse Arnold transform, inverse DWT, two-step phase-shifting wavefront reconstruction, and inverse Fresnel transform can result in the output of a remarkable peak in the central location of the nonlinear correlation coefficient distributions of the recovered image and the standard certification image. Then, the other participant, who possesses the second compressed signal, is authorized to carry out the high-level authentication. Therefore, both compressed signals are collected to reconstruct the original meaningful certification image with a high correlation coefficient. Theoretical analysis and numerical simulations verify the feasibility of the proposed method.

Numerical simulation in a two dimensional turbulent flow over a backward-facing step

International Nuclear Information System (INIS)

Silveira Neto, A. da; Grand, D.

1991-01-01

Numerical simulations of turbulent flows in complex geometries are generally restricted to the prediction of the mean flow and use semi-empirical turbulence models. The present study is devoted to the simulation of the coherence structures which develop in a flow submitted to a velocity change, downstream of a backward facing step. Two aspect ratios (height of the step over height of the channel) have been explored and the values of the Reynolds number vary from (6000 to 90000). In the isothermal case coherent structures have been obtained by the numerical simulation in the mixing layer downstream of the step. The numerical simulations provides results in fairly good agreement with available experimental results. In a second step a thermal stratification is imposed on this flow for one value of Richardson number (0.5) the coherent structures disappear downstream for increasing values of Richardson number. (author)

The gradual development steps of the external coupled RELAP5 - DYN3D code

International Nuclear Information System (INIS)

Strmensky, C.

2001-01-01

This paper describes the on-going and finished parts of project: 'The external coupled RELAP5-DYN3D code'. The development progress was divided into four steps. In present time, second and third steps are performed and four step is started. The two parameters of coolant was selected and are exchanged between codes RELAP5 and DYN3D. (authors)

Investigation to biodiesel production by the two-step homogeneous base-catalyzed transesterification.

Science.gov (United States)

Ye, Jianchu; Tu, Song; Sha, Yong

2010-10-01

For the two-step transesterification biodiesel production made from the sunflower oil, based on the kinetics model of the homogeneous base-catalyzed transesterification and the liquid-liquid phase equilibrium of the transesterification product, the total methanol/oil mole ratio, the total reaction time, and the split ratios of methanol and reaction time between the two reactors in the stage of the two-step reaction are determined quantitatively. In consideration of the transesterification intermediate product, both the traditional distillation separation process and the improved separation process of the two-step reaction product are investigated in detail by means of the rigorous process simulation. In comparison with the traditional distillation process, the improved separation process of the two-step reaction product has distinct advantage in the energy duty and equipment requirement due to replacement of the costly methanol-biodiesel distillation column. Copyright 2010 Elsevier Ltd. All rights reserved.

Two steps hydrothermal growth and characterisations of BaTiO3 films composed of nanowires

Science.gov (United States)

Zawawi, Che Zaheerah Najeehah Che Mohd; Salleh, Shahril; Oon Jew, Lee; Tufail Chaudhary, Kashif; Helmi, Mohamad; Safwan Aziz, Muhammad; Haider, Zuhaib; Ali, Jalil

2018-05-01

Barium titanate (BaTiO3) films composed of nanowires have gained considerable research interest due to their lead-free composition and strong energy conversion efficiency. BaTiO3 films can be developed with a simple two steps hydrothermal reactions, which are low cost effective. In this research, BaTiO3 films were fabricated on titanium foil through two steps hydrothermal method namely, the growth of TiO2 and followed by BaTiO3 films. The structural evolutions and the dielectric properties of the films were investigated as well. The structural evolutions of titanium dioxide (TiO2) and BaTiO3 nanowires were characterized using X-ray diffraction and scanning electron microscopy. First step of hydrothermal reaction, TiO2 nanowires were prepared in varied temperatures of 160 °C, 200 °C and 250 °C respectively. Second step of hydrothermal reaction was performed to produce a layer of BaTiO3 films.

Two-stage categorization in brand extension evaluation: electrophysiological time course evidence.

Directory of Open Access Journals (Sweden)

Qingguo Ma

Full Text Available A brand name can be considered a mental category. Similarity-based categorization theory has been used to explain how consumers judge a new product as a member of a known brand, a process called brand extension evaluation. This study was an event-related potential study conducted in two experiments. The study found a two-stage categorization process reflected by the P2 and N400 components in brand extension evaluation. In experiment 1, a prime-probe paradigm was presented in a pair consisting of a brand name and a product name in three conditions, i.e., in-category extension, similar-category extension, and out-of-category extension. Although the task was unrelated to brand extension evaluation, P2 distinguished out-of-category extensions from similar-category and in-category ones, and N400 distinguished similar-category extensions from in-category ones. In experiment 2, a prime-probe paradigm with a related task was used, in which product names included subcategory and major-category product names. The N400 elicited by subcategory products was more significantly negative than that elicited by major-category products, with no salient difference in P2. We speculated that P2 could reflect the early low-level and similarity-based processing in the first stage, whereas N400 could reflect the late analytic and category-based processing in the second stage.

Examining Extension's Capacity in Community Resource and Economic Development: Viewpoints of Extension Administrators on the Role of Community Resource and Economic Development in the Extension Portfolio

Science.gov (United States)

Urbanowitz, Seth C.; Wilcox, Michael D., Jr.

2013-01-01

The survey-based research reported here offers insights on community, resource, and economic development (CRED) Extension programming at the national and regional level. The results present a national picture of CRED programming, research, and potential future programming opportunities that Extension could capitalize on. The research shows that…

A Two-Step Resume Information Extraction Algorithm

Directory of Open Access Journals (Sweden)

Jie Chen

2018-01-01

Full Text Available With the rapid growth of Internet-based recruiting, there are a great number of personal resumes among recruiting systems. To gain more attention from the recruiters, most resumes are written in diverse formats, including varying font size, font colour, and table cells. However, the diversity of format is harmful to data mining, such as resume information extraction, automatic job matching, and candidates ranking. Supervised methods and rule-based methods have been proposed to extract facts from resumes, but they strongly rely on hierarchical structure information and large amounts of labelled data, which are hard to collect in reality. In this paper, we propose a two-step resume information extraction approach. In the first step, raw text of resume is identified as different resume blocks. To achieve the goal, we design a novel feature, Writing Style, to model sentence syntax information. Besides word index and punctuation index, word lexical attribute and prediction results of classifiers are included in Writing Style. In the second step, multiple classifiers are employed to identify different attributes of fact information in resumes. Experimental results on a real-world dataset show that the algorithm is feasible and effective.

Vygotsky's Principle "One Step in Learning - One Hundred Steps In Development": From Idea To Practice

Directory of Open Access Journals (Sweden)

Zaretsky V.K.,

2016-12-01

Full Text Available The article reviews Lev Vygotsky’s published works to trace the evolution of his understanding of child development. The authors believe that his assumption that one step in learning may mean one hundred steps in development, is as important as the two other key postulates of the cultural-historical theory: the principle that learning precedes development and the concept of zone of proximal development. The authors provide a rationale for utilization of these assumptions in the practice of development-facilitating psychological and educational assistance. A mechanism of this learning-development relationship is hypothesized. The article outlines a multidimensional model of the zone of proximal development illustrating the above mechanism. This model is one of the conceptual tools of the Reflection and Activity Approach helping children overcome learning difficulties and promoting their development. Having given the account of how they proceeded “from the idea to the problem” and “from the idea to the mechanism”, the authors provide case studies showing how this mechanism allows working with learning difficulties to trigger simultaneous improvement in multiple developmental dimensions. The article reports on the experience of running special Summer Schools for children with learning difficulties, implementing the “Chess for General Development” Project, and assisting orphaned children with severe somatic conditions. A case study of a female college student displaying signs of the learned helplessness syndrome is presented. The authors infer that Vygotsky’s idea of a specific relationship between learning and development may be of fundamental theoretical and practical value, especially for working with children with special needs.

Two-step evolution of endosymbiosis between hydra and algae.

Science.gov (United States)

Ishikawa, Masakazu; Shimizu, Hiroshi; Nozawa, Masafumi; Ikeo, Kazuho; Gojobori, Takashi

2016-10-01

In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians. Copyright © 2016 Elsevier Inc. All rights reserved.

Two-Step Evolution of Endosymbiosis between Hydra and Algae

KAUST Repository

Ishikawa, Masakazu

2016-07-09

In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians.

Development process and data management of TurnSTEP, a STEP-compliant CNC system for turning

NARCIS (Netherlands)

Choi, I.; Suh, S.-H; Kim, K.; Song, M.S.; Jang, M.; Lee, B.-E.

2006-01-01

TurnSTEP is one of the earliest STEP-compliant CNC systems for turning. Based on the STEP-NC data model formalized as ISO 14649-12 and 121, it is designed to support intelligent and autonomous control of NC machines for e-manufacturing. The present paper introduces the development process and data

Rapid One-Step Selection Method for Generating Nucleic Acid Aptamers: Development of a DNA Aptamer against alpha-Bungarotoxin

DEFF Research Database (Denmark)

Lauridsen, Lasse Holm; Shamaileh, Hadi A.; Edwards, Stacey L.

2012-01-01

Background: Nucleic acids based therapeutic approaches have gained significant interest in recent years towards the development of therapeutics against many diseases. Recently, research on aptamers led to the marketing of Macugen (R), an inhibitor of vascular endothelial growth factor (VEGF......) for the treatment of age related macular degeneration (AMD). Aptamer technology may prove useful as a therapeutic alternative against an array of human maladies. Considering the increased interest in aptamer technology globally that rival antibody mediated therapeutic approaches, a simplified selection, possibly...... in one-step, technique is required for developing aptamers in limited time period. Principal Findings: Herein, we present a simple one-step selection of DNA aptamers against alpha-bungarotoxin. A toxin immobilized glass coverslip was subjected to nucleic acid pool binding and extensive washing followed...

Development of a Ground Test and Analysis Protocol to Support NASA's NextSTEP Phase 2 Habitation Concepts

Science.gov (United States)

Beaton, Kara H.; Chappell, Steven P.; Bekdash, Omar S.; Gernhardt, Michael L.

2018-01-01

The NASA Next Space Technologies for Exploration Partnerships (NextSTEP) program is a public-private partnership model that seeks commercial development of deep space exploration capabilities to support extensive human spaceflight missions around and beyond cislunar space. NASA first issued the Phase 1 NextSTEP Broad Agency Announcement to U.S. industries in 2014, which called for innovative cislunar habitation concepts that leveraged commercialization plans for low Earth orbit. These habitats will be part of the Deep Space Gateway (DSG), the cislunar space station planned by NASA for construction in the 2020s. In 2016, Phase 2 of the NextSTEP program selected five commercial partners to develop ground prototypes. A team of NASA research engineers and subject matter experts have been tasked with developing the ground test protocol that will serve as the primary means by which these Phase 2 prototype habitats will be evaluated. Since 2008, this core test team has successfully conducted multiple spaceflight analog mission evaluations utilizing a consistent set of operational products, tools, methods, and metrics to enable the iterative development, testing, analysis, and validation of evolving exploration architectures, operations concepts, and vehicle designs. The purpose of implementing a similar evaluation process for the NextSTEP Phase 2 Habitation Concepts is to consistently evaluate the different commercial partner ground prototypes to provide data-driven, actionable recommendations for Phase 3.

Two-Step Condensation of the Ideal Bose Gas in Highly Anisotropic Traps

International Nuclear Information System (INIS)

van Druten, N.J.; Ketterle, W.

1997-01-01

The ideal Bose gas in a highly anisotropic harmonic potential is studied. It is found that Bose-Einstein condensation occurs in two distinct steps as the temperature is lowered. In the first step the specific heat shows a sharp feature, but the system still occupies many one-dimensional quantum states. In the second step, at a significantly lower temperature, the ground state becomes macroscopically occupied. It should be possible to verify these predictions using present-day atom traps. The two-step behavior can occur in a rather general class of anisotropic traps, including the box potential. copyright 1997 The American Physical Society

Two-step impression/ injection, an alternative putty/ wash impression technique: case report.

Science.gov (United States)

Caputi, S; Murmura, G; Sinjari, B; Varvara, G

2012-01-01

We here describe a new technique for making a definitive impression that we refer to as the two-step impression/injection technique. This technique initially follows the classical one-step putty/ light-body impression technique with the polymerization of the putty and the light-body compound. This is then followed by the second step: injection of extra-light-body compound into the preparation through a hole in the metal stock tray. The aim of this additional step is to control the wash bulk and minimize the changes that can produce unfavorable impression results. This new two-step impression/injection technique allows displacement of soft tissues, such as the tongue, during the first seating of the putty and wash materials, while in the second step, the extra-light-body compound records all of the finer details without being compressed.

The effects of age and step length on joint kinematics and kinetics of large out-and-back steps.

Science.gov (United States)

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2008-06-01

Maximum step length (MSL) is a clinical test that has been shown to correlate with age, various measures of fall risk, and knee and hip joint extension speed, strength, and power capacities, but little is known about the kinematics and kinetics of the large out-and-back step utilized. Body motions and ground reaction forces were recorded for 11 unimpaired younger and 10 older women while attaining maximum step length. Joint kinematics and kinetics were calculated using inverse dynamics. The effects of age group and step length on the biomechanics of these large out-and-back steps were determined. Maximum step length was 40% greater in the younger than in the older women (P<0.0001). Peak knee and hip, but not ankle, angle, velocity, moment, and power were generally greater for younger women and longer steps. After controlling for age group, step length generally explained significant additional variance in hip and torso kinematics and kinetics (incremental R2=0.09-0.37). The young reached their peak knee extension moment immediately after landing of the step out, while the old reached their peak knee extension moment just before the return step liftoff (P=0.03). Maximum step length is strongly associated with hip kinematics and kinetics. Delays in peak knee extension moment that appear to be unrelated to step length, may indicate a reduced ability of older women to rapidly apply force to the ground with the stepping leg and thus arrest the momentum of a fall.

Thickness measurement by two-sided step-heating thermal imaging

Science.gov (United States)

Li, Xiaoli; Tao, Ning; Sun, J. G.; Zhang, Cunlin; Zhao, Yuejin

2018-01-01

Infrared thermal imaging is a promising nondestructive technique for thickness prediction. However, it is usually thought to be only appropriate for testing the thickness of thin objects or near-surface structures. In this study, we present a new two-sided step-heating thermal imaging method which employed a low-cost portable halogen lamp as the heating source and verified it with two stainless steel step wedges with thicknesses ranging from 5 mm to 24 mm. We first derived the one-dimensional step-heating thermography theory with the consideration of warm-up time of the lamp, and then applied the nonlinear regression method to fit the experimental data by the derived function to determine the thickness. After evaluating the reliability and accuracy of the experimental results, we concluded that this method is capable of testing thick objects. In addition, we provided the criterions for both the required data length and the applicable thickness range of the testing material. It is evident that this method will broaden the thermal imaging application for thickness measurement.

Decentralised treatment of concentrated sewage at low temperature in a two-step anaerobic system: two upflow-hybrid septic tanks.

Science.gov (United States)

Elmitwalli, T A; Sayed, S; Groendijk, L; van Lier, J; Zeeman, G; Lettinga, G

2003-01-01

The decentralised treatment of concentrated sewage (about 3,600 mgCOD/l) at low temperature was investigated in a two-step anaerobic system: two-anaerobic hybrid (AH) septic tanks (each 0.575 m3). The two reactors were placed in a temperature controlled-room and the HRT was 2.5 days for each reactor. The system was fed with concentrated domestic sewage, mainly black water from about 40 toilets flushed with only 4 litre of water and a limited amount of grey water. The system showed high removal efficiency for the different COD fractions. Mean removal efficiencies in the two-step AH-septic tank at 5 days HRT and 13 degrees C were 94, 98, 74 and 78% for total COD, suspended COD, colloidal COD and dissolved COD respectively. The results of short run experiments indicated that the presence of reticulated polyurethane foam (RPF) media in the AH-septic tank improved the removal of suspended COD by 22%. The first AH-septic tank was full of sludge after 4 months of operation due to the high removal of particulate COD and the limited hydrolysis at low temperature conditions. Therefore, a simple mathematical model was developed based on ADM1 (the IWA model in 2002). Based on the experimental results and the mathematical model, only a one-step AH septic tank is required. An HRT of 5.5-7.5 days is needed for that one-step AH septic tank to treat concentrated sewage at a low temperature of 13 degrees C. Such a system can provide a total COD removal as high as 87% and will be full of sludge after a period of more than a year.

Modified Two-Step Dimethyl Ether (DME Synthesis Simulation from Indonesian Brown Coal

Directory of Open Access Journals (Sweden)

Dwiwahju Sasongko

2016-08-01

Full Text Available A theoretical study was conducted to investigate the performance of dimethyl ether (DME synthesis from coal. This paper presents a model for two-step DME synthesis from brown coal represented by the following processes: drying, gasification, water-gas reaction, acid gas removal, and DME synthesis reactions. The results of the simulation suggest that a feedstock ratio of coal : oxygen : steam of 1 : 0.13 : 0.821 produces the highest DME concentration. The water-gas reactor simulation at a temperature of 400°C and a pressure of 20 bar gave the ratio of H2/CO closest to 2, the optimal value for two-step DME synthesis. As for the DME synthesis reactor simulation, high pressure and low temperature promote a high DME concentration. It is predicted that a temperature of 300°C and a pressure of 140 bar are the optimum conditions for the DME synthesis reaction. This study also showed that the DME concentration produced by the two-step route is higher than that produced by one-step DME synthesis, implying that further improvement and research are needed to apply two-step DME synthesis to production of this liquid fuel.

An overview on STEP-NC compliant controller development

Science.gov (United States)

Othman, M. A.; Minhat, M.; Jamaludin, Z.

2017-10-01

The capabilities of conventional Computer Numerical Control (CNC) machine tools as termination organiser to fabricate high-quality parts promptly, economically and precisely are undeniable. To date, most CNCs follow the programming standard of ISO 6983, also called G & M code. However, in fluctuating shop floor environment, flexibility and interoperability of current CNC system to react dynamically and adaptively are believed still limited. This outdated programming language does not explicitly relate to each other to have control of arbitrary locations other than the motion of the block-by-block. To address this limitation, new standard known as STEP-NC was developed in late 1990s and is formalized as an ISO 14649. It adds intelligence to the CNC in term of interoperability, flexibility, adaptability and openness. This paper presents an overview of the research work that have been done in developing a STEP-NC controller standard and the capabilities of STEP-NC to overcome modern manufacturing demands. Reviews stated that most existing STEP-NC controller prototypes are based on type 1 and type 2 implementation levels. There are still lack of effort being done to develop type 3 and type 4 STEP-NC compliant controller.

Step-By-Step: Life Cycle Radioactive Waste Management

International Nuclear Information System (INIS)

2014-01-01

Radioactive waste is an unavoidable by-product when nuclear technologies are used for electricity production and for beneficial practices in medicine, agriculture, research and industry. When the radioactivity of the waste is above a certain threshold, the waste requires special disposal methods. Through extensive research, standards and approaches have been developed for safely and securely preparing for and managing radioactive waste disposal. In the course of its journey from the point of generation to disposal, radioactive waste undergoes a number of predisposal management treatment steps to transform it into a safe, stable and manageable form suitable for transport, storage and disposal

Railgun-type two step accelerator

International Nuclear Information System (INIS)

Kasai, Satoshi; Maeda, Hikosuke; Onozuka, Masanori; Oda, Yasutsugu; Azuma, Kingo.

1995-01-01

In the two step-type railgun accelerator used in an experimental nuclear fusion device of the present invention, energy of laser beams to be irradiated in an acceleration gas behind a flying object can be reduced, and the voltage applied between the rails can be lowered. Charged particles are generated and supplied to the acceleration gas behind the flying object by a charged particle generating and supplying device so as to promote generation of plasmas caused by irradiation of laser beams. As a result, dielectric break down is caused between the rails by a Paschen's law by application of voltage lower than dielectric breakdown voltage, thereby enabling to generate plasmas easily. Accordingly, the energy of laser beams can be suppressed and the voltage applied between the rails can be lowered. (I.S.)

Railgun-type two step accelerator

Energy Technology Data Exchange (ETDEWEB)

Kasai, Satoshi; Maeda, Hikosuke [Japan Atomic Energy Research Inst., Tokyo (Japan); Onozuka, Masanori; Oda, Yasutsugu; Azuma, Kingo

1995-10-13

In the two step-type railgun accelerator used in an experimental nuclear fusion device of the present invention, energy of laser beams to be irradiated in an acceleration gas behind a flying object can be reduced, and the voltage applied between the rails can be lowered. Charged particles are generated and supplied to the acceleration gas behind the flying object by a charged particle generating and supplying device so as to promote generation of plasmas caused by irradiation of laser beams. As a result, dielectric break down is caused between the rails by a Paschen`s law by application of voltage lower than dielectric breakdown voltage, thereby enabling to generate plasmas easily. Accordingly, the energy of laser beams can be suppressed and the voltage applied between the rails can be lowered. (I.S.).

Action research: A practical step-by-step guide for Agricultural ...

African Journals Online (AJOL)

Based on the findings, the extensionists will be able to identify the action required to improve upon the existing situation. This calls for knowledge and skills in action oriented research. This paper provides simple, easy to follow, step-by-step guidelines which should be suitable for many situations in extension research ...

Development of STEP-NC Adaptor for Advanced Web Manufacturing System

Science.gov (United States)

Ajay Konapala, Mr.; Koona, Ramji, Dr.

2017-08-01

Information systems play a key role in the modern era of Information Technology. Rapid developments in IT & global competition calls for many changes in basic CAD/CAM/CAPP/CNC manufacturing chain of operations. ‘STEP-NC’ an enhancement to STEP for operating CNC machines, creating new opportunities for collaborative, concurrent, adaptive works across the manufacturing chain of operations. Schemas and data models defined by ISO14649 in liaison with ISO10303 standards made STEP-NC file rich with feature based, rather than mere point to point information of G/M Code format. But one needs to have a suitable information system to understand and modify these files. Various STEP-NC information systems are reviewed to understand the suitability of STEP-NC for web manufacturing. Present work also deals with the development of an adaptor which imports STEP-NC file, organizes its information, allowing modifications to entity values and finally generates a new STEP-NC file to export. The system is designed and developed to work on web to avail additional benefits through the web and also to be part of a proposed ‘Web based STEP-NC manufacturing platform’ which is under development and explained as future scope.

A Two-Step Approach to Analyze Satisfaction Data

Science.gov (United States)

Ferrari, Pier Alda; Pagani, Laura; Fiorio, Carlo V.

2011-01-01

In this paper a two-step procedure based on Nonlinear Principal Component Analysis (NLPCA) and Multilevel models (MLM) for the analysis of satisfaction data is proposed. The basic hypothesis is that observed ordinal variables describe different aspects of a latent continuous variable, which depends on covariates connected with individual and…

CIDOC-CRM extensions for conservation processes: A methodological approach

Science.gov (United States)

Vassilakaki, Evgenia; Zervos, Spiros; Giannakopoulos, Georgios

2015-02-01

This paper aims to report the steps taken to create the CIDOC Conceptual Reference Model (CIDOC-CRM) extensions and the relationships established to accommodate the depiction of conservation processes. In particular, the specific steps undertaken for developing and applying the CIDOC-CRM extensions for defining the conservation interventions performed on the cultural artifacts of the National Archaeological Museum of Athens, Greece are presented in detail. A report on the preliminary design of the DOC-CULTURE project (Development of an integrated information environment for assessment and documentation of conservation interventions to cultural works/objects with nondestructive testing techniques [NDTs], www.ndt-lab.gr/docculture), co-financed by the European Union NSRF THALES program, can be found in Kyriaki-Manessi, Zervos & Giannakopoulos (1) whereas the NDT&E methods and their output data through CIDOC-CRM extension of the DOC-CULTURE project approach to standardize the documentation of the conservation were further reported in Kouis et al. (2).

Participatory Contact Farmer Selection: Survey of two Extension ...

African Journals Online (AJOL)

This paper tested individual and group socio-metric nomination of potential contact farmers and compared the nominations with the CFs working in two extension circles. It was shown that only three (3) CFs out of eight (8) in the study appeared on both the individual and group nominations. It was recommended that EAs ...

A two-step quantum secure direct communication protocol with hyperentanglement

International Nuclear Information System (INIS)

Gu Bin; Zhang Cheng-Yi; Huang Yu-Gai; Fang Xia

2011-01-01

We propose a two-step quantum secure direct communication (QSDC) protocol with hyperentanglement in both the spatial-mode and the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal. The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently. This QSDC protocol has a higher capacity than the original two-step QSDC protocol as each photon pair can carry 4 bits of information. Compared with the QSDC protocol based on hyperdense coding, this QSDC protocol has the immunity to Trojan horse attack strategies with the process for determining the number of the photons in each quantum signal as it is a one-way quantum communication protocol. (general)

Coupling of Spinosad Fermentation and Separation Process via Two-Step Macroporous Resin Adsorption Method.

Science.gov (United States)

Zhao, Fanglong; Zhang, Chuanbo; Yin, Jing; Shen, Yueqi; Lu, Wenyu

2015-08-01

In this paper, a two-step resin adsorption technology was investigated for spinosad production and separation as follows: the first step resin addition into the fermentor at early cultivation period to decrease the timely product concentration in the broth; the second step of resin addition was used after fermentation to adsorb and extract the spinosad. Based on this, a two-step macroporous resin adsorption-membrane separation process for spinosad fermentation, separation, and purification was established. Spinosad concentration in 5-L fermentor increased by 14.45 % after adding 50 g/L macroporous at the beginning of fermentation. The established two-step macroporous resin adsorption-membrane separation process got the 95.43 % purity and 87 % yield for spinosad, which were both higher than that of the conventional crystallization of spinosad from aqueous phase that were 93.23 and 79.15 % separately. The two-step macroporous resin adsorption method has not only carried out the coupling of spinosad fermentation and separation but also increased spinosad productivity. In addition, the two-step macroporous resin adsorption-membrane separation process performs better in spinosad yield and purity.

Two-Step Amyloid Aggregation: Sequential Lag Phase Intermediates

Science.gov (United States)

Castello, Fabio; Paredes, Jose M.; Ruedas-Rama, Maria J.; Martin, Miguel; Roldan, Mar; Casares, Salvador; Orte, Angel

2017-01-01

The self-assembly of proteins into fibrillar structures called amyloid fibrils underlies the onset and symptoms of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. However, the molecular basis and mechanism of amyloid aggregation are not completely understood. For many amyloidogenic proteins, certain oligomeric intermediates that form in the early aggregation phase appear to be the principal cause of cellular toxicity. Recent computational studies have suggested the importance of nonspecific interactions for the initiation of the oligomerization process prior to the structural conversion steps and template seeding, particularly at low protein concentrations. Here, using advanced single-molecule fluorescence spectroscopy and imaging of a model SH3 domain, we obtained direct evidence that nonspecific aggregates are required in a two-step nucleation mechanism of amyloid aggregation. We identified three different oligomeric types according to their sizes and compactness and performed a full mechanistic study that revealed a mandatory rate-limiting conformational conversion step. We also identified the most cytotoxic species, which may be possible targets for inhibiting and preventing amyloid aggregation.

Influence of step complexity and presentation style on step performance of computerized emergency operating procedures

Energy Technology Data Exchange (ETDEWEB)

Xu Song [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China); Li Zhizhong [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: zzli@tsinghua.edu.cn; Song Fei; Luo Wei; Zhao Qianyi; Salvendy, Gavriel [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China)

2009-02-15

With the development of information technology, computerized emergency operating procedures (EOPs) are taking the place of paper-based ones. However, ergonomics issues of computerized EOPs have not been studied adequately since the industrial practice is quite limited yet. This study examined the influence of step complexity and presentation style of EOPs on step performance. A simulated computerized EOP system was developed in two presentation styles: Style A: one- and two-dimensional flowcharts combination; Style B: two-dimensional flowchart and success logic tree combination. Step complexity was quantified by a complexity measure model based on an entropy concept. Forty subjects participated in the experiment of EOP execution using the simulated system. The results of data analysis on the experiment data indicate that step complexity and presentation style could significantly influence step performance (both step error rate and operation time). Regression models were also developed. The regression analysis results imply that operation time of a step could be well predicted by step complexity while step error rate could only partly predicted by it. The result of a questionnaire investigation implies that step error rate was influenced not only by the operation task itself but also by other human factors. These findings may be useful for the design and assessment of computerized EOPs.

Professional development and extension programs

Energy Technology Data Exchange (ETDEWEB)

Bereznai, G. [University of Ontario Institute of Technology, Oshawa, ON (Canada)

2015-07-01

Professional Development (PD) refers to the means by which people acquire, develop, maintain and enhance the specialist knowledge and skills needed to practice in their profession. Extension Programs (aka Continuing Education) are offered by most post-secondary degree/diploma/certificate granting institutions.The courses are typically taken on a part-time basis, and course delivery often includes distance learning technology. An important implementation of PD is via workplace training, industry specific seminars, workshops and non-credit courses offered by a wide range of service providers.

Professional development and extension programs

International Nuclear Information System (INIS)

Bereznai, G.

2015-01-01

Professional Development (PD) refers to the means by which people acquire, develop, maintain and enhance the specialist knowledge and skills needed to practice in their profession. Extension Programs (aka Continuing Education) are offered by most post-secondary degree/diploma/certificate granting institutions.The courses are typically taken on a part-time basis, and course delivery often includes distance learning technology. An important implementation of PD is via workplace training, industry specific seminars, workshops and non-credit courses offered by a wide range of service providers.

Two endogenous proteins that induce cell wall extension in plants

Science.gov (United States)

McQueen-Mason, S.; Durachko, D. M.; Cosgrove, D. J.

1992-01-01

Plant cell enlargement is regulated by wall relaxation and yielding, which is thought to be catalyzed by elusive "wall-loosening" enzymes. By employing a reconstitution approach, we found that a crude protein extract from the cell walls of growing cucumber seedlings possessed the ability to induce the extension of isolated cell walls. This activity was restricted to the growing region of the stem and could induce the extension of isolated cell walls from various dicot stems and the leaves of amaryllidaceous monocots, but was less effective on grass coleoptile walls. Endogenous and reconstituted wall extension activities showed similar sensitivities to pH, metal ions, thiol reducing agents, proteases, and boiling in methanol or water. Sequential HPLC fractionation of the active wall extract revealed two proteins with molecular masses of 29 and 30 kD associated with the activity. Each protein, by itself, could induce wall extension without detectable hydrolytic breakdown of the wall. These proteins appear to mediate "acid growth" responses of isolated walls and may catalyze plant cell wall extension by a novel biochemical mechanism.

MIDPOINT TWO- STEPS RULE FOR THE SQUARE ROOT METHOD

African Journals Online (AJOL)

DR S.E UWAMUSI

Aberth third order method for finding zeros of a polynomial in interval ... KEY WORDS: Square root iteration, midpoint two steps Method, ...... A New set of Methods for the simultaneous determination of zeros of polynomial equation and iterative ...

Using Informal Articles in Extensive Reading (ER Program: A Personal Experience

Directory of Open Access Journals (Sweden)

Chothibul Umam

2015-12-01

Full Text Available In this digital age, informal articles which contain some valuable informations and extensive input to develop the learners’ language proficiency are easily found on internet or other reading sources. Unfortunately most literature shows that informal articles are not widely used in extensive reading (henceforth ER program. For this reason, the paper introduces steps procedure in using informal articles as authentic material in one semester ER program for Indonesian EFL college learners. The procedure is developed on the basis of my great interest in creating innovative way in teaching ER at one of the State Institute for Islamic Studies in Indonesia. The proposed steps are expected to be an alternative pathway in teaching ER for English teachers particularly at a college-university level. Keywords: Extensive Reading, informal article.Copyright © 2015 by Al-Ta'lim All right reserved

Efficient One-Step Fusion PCR Based on Dual-Asymmetric Primers and Two-Step Annealing

DEFF Research Database (Denmark)

Liu, Yilan; Chen, Jinjin; Thygesen, Anders

2018-01-01

Gene splicing by fusion PCR is a versatile and widely used methodology, especially in synthetic biology. We here describe a rapid method for splicing two fragments by one-round fusion PCR with a dual-asymmetric primers and two-step annealing (ODT) method. During the process, the asymmetric...... intermediate fragments were generated in the early stage. Thereafter, they were hybridized in the subsequent cycles to serve as template for the target full-length product. The process parameters such as primer ratio, elongation temperature and cycle numbers were optimized. In addition, the fusion products...

Two-Step Classification of Unemployed People in the Czech Republic

Directory of Open Access Journals (Sweden)

Zdeněk Šulc

2015-03-01

Full Text Available The paper analyzes structure and behavior of unemployed people in the Czech Republic by means of latent class analysis (LCA and CHAID analysis where the output of LCA serves as the input for CHAID. The unemployed are classified in two steps; for each step different characteristics are used. In the first step, respondents are split into latent classes according to their answers to questions concerning ways of searching for a new job. In the second step, CHAID analysis is performed with results obtained from LCA as a dependent variable. In the paper, data from periodical Labor Force Survey conducted in Czech Republic in spring 2011 are used. The results indicate that unemployed people in the Czech Republic can be divided into four segments: Active, Passive, Typical and Specific. A special attention is paid to extreme segments Active and Passive.

A two-step transport pathway allows the mother cell to nurture the developing spore in Bacillus subtilis.

Science.gov (United States)

Ramírez-Guadiana, Fernando H; Meeske, Alexander J; Rodrigues, Christopher D A; Barajas-Ornelas, Rocío Del Carmen; Kruse, Andrew C; Rudner, David Z

2017-09-01

One of the hallmarks of bacterial endospore formation is the accumulation of high concentrations of pyridine-2,6-dicarboxylic acid (dipicolinic acid or DPA) in the developing spore. This small molecule comprises 5-15% of the dry weight of dormant spores and plays a central role in resistance to both wet heat and desiccation. DPA is synthesized in the mother cell at a late stage in sporulation and must be translocated across two membranes (the inner and outer forespore membranes) that separate the mother cell and forespore. The enzymes that synthesize DPA and the proteins required to translocate it across the inner forespore membrane were identified over two decades ago but the factors that transport DPA across the outer forespore membrane have remained mysterious. Here, we report that SpoVV (formerly YlbJ) is the missing DPA transporter. SpoVV is produced in the mother cell during the morphological process of engulfment and specifically localizes in the outer forespore membrane. Sporulating cells lacking SpoVV produce spores with low levels of DPA and cells engineered to express SpoVV and the DPA synthase during vegetative growth accumulate high levels of DPA in the culture medium. SpoVV resembles concentrative nucleoside transporters and mutagenesis of residues predicted to form the substrate-binding pocket supports the idea that SpoVV has a similar structure and could therefore function similarly. These findings provide a simple two-step transport mechanism by which the mother cell nurtures the developing spore. DPA produced in the mother cell is first translocated into the intermembrane space by SpoVV and is then imported into the forespore by the SpoVA complex. This pathway is likely to be broadly conserved as DPA synthase, SpoVV, and SpoVA proteins can be found in virtually all endospore forming bacteria.

Nonvolatile two-step, two-color holography with continuous-wave lights for both congruent and near-stoichiometric LiNbO3:Fe

International Nuclear Information System (INIS)

Shen Yan; Zhang Guoquan; Fu Bo; Xu Qingjun; Xu Jingjun

2004-01-01

We have studied theoretically the steady-state nonvolatile two-step, two-color holographic recording performance for both the congruent and the near-stoichiometric LiNbO 3 :Fe based on the two-center model (the deep-trap and the shallow-trap centers are Fe 2+ /Fe 3+ and Nb Li 4+ /Nb Li 5+ , respectively). The results show that the direct electron exchange between the Fe 2+ /Fe 3+ centers and the Nb Li 4+ /Nb Li 5+ centers due to the tunneling effect dominates the charge-transfer process during the nonvolatile two-step, two-color holography and determines the two-step, two-color holography performance in LiNbO 3 :Fe. We have further studied the effects of the crystal stoichiometry on the performance of the two-step, two-color holography. It is shown that, as far as the total space-charge field is considered, the nonvolatile two-step, two-color holography performance in the near-stoichiometric LiNbO 3 :Fe is much better than that in the congruent LiNbO 3 :Fe within the intensity range reachable by the continuous-wave lights

A two-step superplastic forging forming of semi-continuously cast AZ70 magnesium alloy

Directory of Open Access Journals (Sweden)

Pan Wang

2015-03-01

Full Text Available A two-step technology combined forging with superplastic forming has been developed to enhance the forgeability of semi-continuously cast AZ70 magnesium alloy and realize the application of the as-cast magnesium alloy in large deformation bullet shell. In the first step, fine-grained microstructure preforms that are suitable for superplastic forming were obtained by reasonably designing the size of the initial blanks with the specific height-to-diameter ratio, upsetting the blanks and subsequent annealing. In the second step, the heat treated preforms were forged into the end products at the superplastic conditions. The end products exhibit high quality surface and satisfied microstructure. Consequently, this forming technology that not only avoids complicating the material preparation but also utilizes higher strain rate superplastic provides a near net-shaped novel method on magnesium forging forming technology using as-cast billet.

Trainer variability during step training after spinal cord injury: Implications for robotic gait-training device design.

Science.gov (United States)

Galvez, Jose A; Budovitch, Amy; Harkema, Susan J; Reinkensmeyer, David J

2011-01-01

Robotic devices are being developed to automate repetitive aspects of walking retraining after neurological injuries, in part because they might improve the consistency and quality of training. However, it is unclear how inconsistent manual training actually is or whether stepping quality depends strongly on the trainers' manual skill. The objective of this study was to quantify trainer variability of manual skill during step training using body-weight support on a treadmill and assess factors of trainer skill. We attached a sensorized orthosis to one leg of each patient with spinal cord injury and measured the shank kinematics and forces exerted by different trainers during six training sessions. An expert trainer rated the trainers' skill level based on videotape recordings. Between-trainer force variability was substantial, about two times greater than within-trainer variability. Trainer skill rating correlated strongly with two gait features: better knee extension during stance and fewer episodes of toe dragging. Better knee extension correlated directly with larger knee horizontal assistance force, but better toe clearance did not correlate with larger ankle push-up force; rather, it correlated with better knee and hip extension. These results are useful to inform robotic gait-training design.

From representing to modelling knowledge: Proposing a two-step training for excellence in concept mapping

Directory of Open Access Journals (Sweden)

Joana G. Aguiar

2017-09-01

Full Text Available Training users in the concept mapping technique is critical for ensuring a high-quality concept map in terms of graphical structure and content accuracy. However, assessing excellence in concept mapping through structural and content features is a complex task. This paper proposes a two-step sequential training in concept mapping. The first step requires the fulfilment of low-order cognitive objectives (remember, understand and apply to facilitate novices’ development into good Cmappers by honing their knowledge representation skills. The second step requires the fulfilment of high-order cognitive objectives (analyse, evaluate and create to grow good Cmappers into excellent ones through the development of knowledge modelling skills. Based on Bloom’s revised taxonomy and cognitive load theory, this paper presents theoretical accounts to (1 identify the criteria distinguishing good and excellent concept maps, (2 inform instructional tasks for concept map elaboration and (3 propose a prototype for training users on concept mapping combining online and face-to-face activities. The proposed training application and the institutional certification are the next steps for the mature use of concept maps for educational as well as business purposes.

Lateral stability of the spring-mass hopper suggests a two-step control strategy for running.

Science.gov (United States)

Carver, Sean G; Cowan, Noah J; Guckenheimer, John M

2009-06-01

This paper investigates the control of running gaits in the context of a spring loaded inverted pendulum model in three dimensions. Specifically, it determines the minimal number of steps required for an animal to recover from a perturbation to a specified gait. The model has four control inputs per step: two touchdown angles (azimuth and elevation) and two spring constants (compression and decompression). By representing the locomotor movement as a discrete-time return map and using the implicit function theorem we show that the number of recovery steps needed following a perturbation depends upon the goals of the control mechanism. When the goal is to follow a straight line, two steps are necessary and sufficient for small lateral perturbations. Multistep control laws have a larger number of control inputs than outputs, so solutions of the control problem are not unique. Additional constraints, referred to here as synergies, are imposed to determine unique control inputs for perturbations. For some choices of synergies, two-step control can be expressed as two iterations of its first step policy and designed so that recovery occurs in just one step for all perturbations for which one-step recovery is possible.

Efficiency enhancement of the MAPbI3-xClx-based perovskite solar cell by a two-step annealing procedure

Science.gov (United States)

Huang, Jin; Wang, Minqiang; Ding, Lei; Deng, Jianping; Yao, Xi

2016-02-01

The development of a novel two-step annealing method has contributed to the significantly improved performance of the MAPbI3-xClx based perovskite solar cell (PSC). By utilizing a two-step annealing method, we obtained a high power conversion efficiency (PCE) of 12.72% with a current density (J sc) of 18.35 mA cm-2, an open circuit voltage (V oc) of 0.90 V and a fill factor (FF) of 0.71. Noticeably, the two-step annealed device shows no hysteresis and exhibits a PCE which is approximately 1.2 times greater than that of the one-step annealed device. The improvement in device efficiency is ascribed to the reduced series resistance, increased parallel resistance, better surface coverage, lower leakage current and stronger crystallization of the MAPbI3-xClx perovskite layer.

Morphology-photovoltaic property correlation in perovskite solar cells: One-step versus two-step deposition of CH3NH3PbI3

Directory of Open Access Journals (Sweden)

Jeong-Hyeok Im

2014-08-01

Full Text Available Perovskite CH3NH3PbI3 light absorber is deposited on the mesoporous TiO2 layer via one-step and two-step coating methods and their photovoltaic performances are compared. One-step coating using a solution containing CH3NH3I and PbI2 shows average power conversion efficiency (PCE of 7.5%, while higher average PCE of 13.9% is obtained from two-step coating method, mainly due to higher voltage and fill factor. The coverage, pore-filling, and morphology of the deposited perovskite are found to be critical in photovoltaic performance of the mesoporous TiO2 based perovskite solar cells.

a comparative study of two agricultural extension approaches in ...

African Journals Online (AJOL)

each approach are described and their strengths and weaknesses are revealed including the implications of having two extension ... line of technical support and administrative control, b) to change the multi-purpose role ... evaluation and training plots called Management Training Plots (MTPs). According to Quinones et al; ...

Two-centre interference effects on the Thomas two-step scattering mechanisms

International Nuclear Information System (INIS)

Adivi, E Ghanbari

2010-01-01

The charge transfer process in the collision of fast protons with hydrogen molecules is theoretically investigated using the second-order Born approximation with correct boundary conditions. In addition to two first-order terms, the present calculations include the three second-order terms which correspond to the Thomas two-step scattering mechanisms. The interference effects, due to the scattering of the particles from two atomic centres, on the electron capture differential cross sections vary significantly with the orientation of the molecule and with the impact energy. After the averaging over all molecular orientations the interference patterns disappear but the Thomas peak becomes more pronounced. These patterns are also apparent in the differential cross sections as a function of the angle between the molecular axis and the incident beam direction. The integrated cross sections are calculated and the results are compared with available experimental data.

Strong Stability Preserving Two-step Runge–Kutta Methods

KAUST Repository

Ketcheson, David I.; Gottlieb, Sigal; Macdonald, Colin B.

2011-01-01

We investigate the strong stability preserving (SSP) property of two-step Runge–Kutta (TSRK) methods. We prove that all SSP TSRK methods belong to a particularly simple subclass of TSRK methods, in which stages from the previous step are not used. We derive simple order conditions for this subclass. Whereas explicit SSP Runge–Kutta methods have order at most four, we prove that explicit SSP TSRK methods have order at most eight. We present explicit TSRK methods of up to eighth order that were found by numerical search. These methods have larger SSP coefficients than any known methods of the same order of accuracy and may be implemented in a form with relatively modest storage requirements. The usefulness of the TSRK methods is demonstrated through numerical examples, including integration of very high order weighted essentially non-oscillatory discretizations.

Strong Stability Preserving Two-step Runge–Kutta Methods

KAUST Repository

Ketcheson, David I.

2011-12-22

We investigate the strong stability preserving (SSP) property of two-step Runge–Kutta (TSRK) methods. We prove that all SSP TSRK methods belong to a particularly simple subclass of TSRK methods, in which stages from the previous step are not used. We derive simple order conditions for this subclass. Whereas explicit SSP Runge–Kutta methods have order at most four, we prove that explicit SSP TSRK methods have order at most eight. We present explicit TSRK methods of up to eighth order that were found by numerical search. These methods have larger SSP coefficients than any known methods of the same order of accuracy and may be implemented in a form with relatively modest storage requirements. The usefulness of the TSRK methods is demonstrated through numerical examples, including integration of very high order weighted essentially non-oscillatory discretizations.

Effect of two-step and one-step surface conditioning of glass ceramic on adhesion strength of orthodontic bracket and effect of thermo-cycling on adhesion strength.

Science.gov (United States)

Asiry, Moshabab A; AlShahrani, Ibrahim; Alaqeel, Samer M; Durgesh, Bangalore H; Ramakrishnaiah, Ravikumar

2018-08-01

The adhesion strength of orthodontic brackets bonded to dental glass ceramics was evaluated after ceramic surface was treated with two-step and one-step surface conditioning systems, and subjecting to thermo-cycling. A total of forty specimens were fabricated from silica based glass ceramic (lithium disilicate) by duplicating the buccal surface of maxillary first premolar. The specimens were randomly assigned to two experimental groups (n = 20), group one specimens were treated with two-step surface conditioning system (IPS ceramic etching gel™ and Monobond plus™) and group two specimens were treated with one-step surface conditioning system (Monobond etch and prime™). The surface roughness of the specimens after treatment with two-step and one-step surface conditioning system was measured using non-contact surface profilometer. Ten randomly selected specimens from each group were subjected to thermo-cycling and the remaining ten served as baseline. The shear bond strength of the specimens was measured using universal material testing machine. The adhesive remnant index score was calculated, and the results of surface roughness and bond strength were tabulated and subjected to analysis of variance and post hoc tukey's test at a significance level of p step conditioning system had higher surface roughness and bond strength than one-step conditioning system. The majority of the specimens treated with both two-step and one-step conditioned specimens showed adhesive failure after subjecting thermo-cycling. Traditional two-step conditioning provides better bond strength. The clinical importance of the study is that, the silane promoted adhesion significantly reduces on exposure to thermo-cycling. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Development of a National Agricultural Extension Policy in Bangladesh.

Science.gov (United States)

Walker, M.; Sarkar, A. A.

1996-01-01

The background of agriculture in Bangladesh and the process of developing a national agricultural extension policy focused on sustainable development are described. The policy explicates the meaning of agricultural extension, use of agricultural knowledge and information systems, and 11 core principles. (SK)

Zinc hexacyanoferrate film as an effective protecting layer in two-step and one-step electropolymerization of pyrrole on zinc substrate

Energy Technology Data Exchange (ETDEWEB)

Pournaghi-Azar, M.H. [Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)]. E-mail: pournaghiazar@tabrizu.ac.ir; Nahalparvari, H. [Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

2005-03-15

The two-step and one-step electrosynthesis processes of polypyrrole (PPy) films on the zinc substrate are described. The two-step process includes (i) the zinc surface pretreatment with hexacyanoferrate ion in the aqueous medium in order to form a zinc hexacyanoferrate (ZnHCF) film non-blocking passive layer on the surface and with the view to prevent its reactivity and (ii) electropolymerization of pyrrole on the ZnHCF vertical bar Zn-modified electrode in aqueous pyrrole solution. In this context, both the non-electrolytic and electrolytic procedures were adapted, and the effect of some experimental conditions such as supporting electrolyte, pH and temperature of the solution at the zinc surface pretreatment step as well as pyrrole concentration and electrochemical techniques at the polymerization step was investigated. By optimizing the experimental conditions in both steps, we have obtained a homogeneous and strongly adherent PPy films on the zinc substrate. The one-step process is based on the use of an aqueous medium containing Fe(CN){sub 6}{sup 4-} and pyrrole. The ferrocyanide ion passivates the substrate by formation of ZnHCF film during the electropolymerization process of pyrrole and therefore makes it possible to obtain strongly adherent PPy films, with controlled thickness, either by cyclic voltammetry or by electrolysis at constant current or constant potential without any previously treatment of the zinc electrode surface. The polypyrrole films deposited on the zinc electrode were characterized by cyclic voltammetry and scanning electron microscopic (SEM) measurement.

Zinc hexacyanoferrate film as an effective protecting layer in two-step and one-step electropolymerization of pyrrole on zinc substrate

International Nuclear Information System (INIS)

Pournaghi-Azar, M.H.; Nahalparvari, H.

2005-01-01

The two-step and one-step electrosynthesis processes of polypyrrole (PPy) films on the zinc substrate are described. The two-step process includes (i) the zinc surface pretreatment with hexacyanoferrate ion in the aqueous medium in order to form a zinc hexacyanoferrate (ZnHCF) film non-blocking passive layer on the surface and with the view to prevent its reactivity and (ii) electropolymerization of pyrrole on the ZnHCF vertical bar Zn-modified electrode in aqueous pyrrole solution. In this context, both the non-electrolytic and electrolytic procedures were adapted, and the effect of some experimental conditions such as supporting electrolyte, pH and temperature of the solution at the zinc surface pretreatment step as well as pyrrole concentration and electrochemical techniques at the polymerization step was investigated. By optimizing the experimental conditions in both steps, we have obtained a homogeneous and strongly adherent PPy films on the zinc substrate. The one-step process is based on the use of an aqueous medium containing Fe(CN) 6 4- and pyrrole. The ferrocyanide ion passivates the substrate by formation of ZnHCF film during the electropolymerization process of pyrrole and therefore makes it possible to obtain strongly adherent PPy films, with controlled thickness, either by cyclic voltammetry or by electrolysis at constant current or constant potential without any previously treatment of the zinc electrode surface. The polypyrrole films deposited on the zinc electrode were characterized by cyclic voltammetry and scanning electron microscopic (SEM) measurement

Tardily accelerated neurologic deterioration in two-step thallium intoxication.

Science.gov (United States)

Kuroda, Hiroshi; Mukai, Yoshiyuki; Nishiyama, Shuhei; Takeshita, Takayuki; Tateyama, Maki; Takeda, Atsushi; Aoki, Masashi

2016-12-01

Thallium intoxication was reported in cases with accidental ingestion, suicide attempt, and criminal adulteration. Reported cases were mostly one-time ingestion, therefore, the clinical course of divisional ingestion has not been fully known. Here, we report a case with two-step thallium intoxication manifesting as tardily accelerated neurologic deterioration. A 16-year-old adolescent was cryptically poisoned with thallium sulfate twice at an interval of 52days. After the first ingestion, neurologic symptoms including visual loss, myalgia, and weakness in legs developed about 40days after the development of acute gastrointestinal symptoms and alopecia. After the second ingestion, neurologic symptoms deteriorated rapidly and severely without gastrointestinal or cutaneous symptoms. Brain magnetic resonance imaging exhibited bilateral optic nerve atrophy. Nerve conduction studies revealed severe peripheral neuropathies in legs. Thallium intoxication was confirmed by an increase in urine thallium egestion. Most of the neurologic manifestations ameliorated in two years, but the visual loss persisted. The source of thallium ingestion was unraveled afterward because a murder suspect in another homicidal assault confessed the forepast adulteration. This discriminating clinical course may be attributable to the cumulative neurotoxicity due to the longer washout-time of thallium in the nervous system than other organs. It is noteworthy that the divisional thallium intoxication may manifest as progressive optic and peripheral neuropathy without gastrointestinal or cutaneous symptoms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Step-by-Step Visual Manuals: Design and Development

Science.gov (United States)

Urata, Toshiyuki

2004-01-01

The types of handouts and manuals that are used in technology training vary. Some describe procedures in a narrative way without graphics; some employ step-by-step instructions with screen captures. According to Thirlway (1994), a training manual should be like a tutor that permits a student to learn at his own pace and gives him confidence for…

Preparation of three-dimensional shaped aluminum alloy foam by two-step foaming

International Nuclear Information System (INIS)

Shang, J.T.; Xuming, Chu; Deping, He

2008-01-01

A novel method, named two-step foaming, was investigated to prepare three-dimensional shaped aluminum alloy foam used in car industry, spaceflight, packaging and related areas. Calculations of thermal decomposition kinetics of titanium hydride showed that there is a considerable amount of hydrogen releasing when the titanium hydride is heated at a relatively high temperature after heated at a lower temperature. The hydrogen mass to sustain aluminum alloy foam, having a high porosity, was also estimated by calculations. Calculations indicated that as-received titanium hydride without any pre-treatment can be used as foaming agents in two-step foaming. The processes of two-step foaming, including preparing precursors and baking, were also studied by experiments. Results showed that, low titanium hydride dispersion temperature, long titanium hydride dispersion time and low precursors porosity are beneficial to prepare three-dimensional shaped aluminum alloy foams with uniform pores

A permeation theory for single-file ion channels: one- and two-step models.

Science.gov (United States)

Nelson, Peter Hugo

2011-04-28

How many steps are required to model permeation through ion channels? This question is investigated by comparing one- and two-step models of permeation with experiment and MD simulation for the first time. In recent MD simulations, the observed permeation mechanism was identified as resembling a Hodgkin and Keynes knock-on mechanism with one voltage-dependent rate-determining step [Jensen et al., PNAS 107, 5833 (2010)]. These previously published simulation data are fitted to a one-step knock-on model that successfully explains the highly non-Ohmic current-voltage curve observed in the simulation. However, these predictions (and the simulations upon which they are based) are not representative of real channel behavior, which is typically Ohmic at low voltages. A two-step association/dissociation (A/D) model is then compared with experiment for the first time. This two-parameter model is shown to be remarkably consistent with previously published permeation experiments through the MaxiK potassium channel over a wide range of concentrations and positive voltages. The A/D model also provides a first-order explanation of permeation through the Shaker potassium channel, but it does not explain the asymmetry observed experimentally. To address this, a new asymmetric variant of the A/D model is developed using the present theoretical framework. It includes a third parameter that represents the value of the "permeation coordinate" (fractional electric potential energy) corresponding to the triply occupied state n of the channel. This asymmetric A/D model is fitted to published permeation data through the Shaker potassium channel at physiological concentrations, and it successfully predicts qualitative changes in the negative current-voltage data (including a transition to super-Ohmic behavior) based solely on a fit to positive-voltage data (that appear linear). The A/D model appears to be qualitatively consistent with a large group of published MD simulations, but no

A two-dimensional lattice equation as an extension of the Heideman-Hogan recurrence

Science.gov (United States)

Kamiya, Ryo; Kanki, Masataka; Mase, Takafumi; Tokihiro, Tetsuji

2018-03-01

We consider a two dimensional extension of the so-called linearizable mappings. In particular, we start from the Heideman-Hogan recurrence, which is known as one of the linearizable Somos-like recurrences, and introduce one of its two dimensional extensions. The two dimensional lattice equation we present is linearizable in both directions, and has the Laurent and the coprimeness properties. Moreover, its reduction produces a generalized family of the Heideman-Hogan recurrence. Higher order examples of two dimensional linearizable lattice equations related to the Dana Scott recurrence are also discussed.

Ultrasonic transesterification of Jatrophacurcas L. oil to biodiesel by a two-step process

International Nuclear Information System (INIS)

Deng Xin; Fang Zhen; Liu Yunhu

2010-01-01

Transesterification of high free fatty acid content Jatropha oil with methanol to biodiesel catalyzed directly by NaOH and high-concentrated H 2 SO 4 or by two-step process were studied in an ultrasonic reactor at 60 deg. C. If NaOH was used as catalyst, biodiesel yield was only 47.2% with saponification problem. With H 2 SO 4 as catalyst, biodiesel yield was increased to 92.8%. However, longer reaction time (4 h) was needed and the biodiesel was not stable. A two-step, acid-esterification and base-transesterification process was further used for biodiesel production. It was found that after the first-step pretreatment with H 2 SO 4 for 1 h, the acid value of Jatropha oil was reduced from 10.45 to 1.2 mg KOH/g, and subsequently, NaOH was used for the second-step transesterification. Stable and clear yellowish biodiesel was obtained with 96.4% yield after reaction for 0.5 h. The total production time was only 1.5 h that is just half of the previous reported. The two-step process with ultrasonic radiation is effective and time-saving for biodiesel production from Jatropha oil.

Managing BWR plant life extension

International Nuclear Information System (INIS)

Ianni, P.W.; Kiss, E.

1985-01-01

Recent studies have confirmed that extending the useful life of a large nuclear plant can be justified with very high cost benefit ratio. In turn, experience with large power plant systems and equipment has shown that a well-integrated and -managed plan is essential in order to achieve potential economic benefits. Consequently, General Electric's efforts have been directed at establishing a life extension plan that considers alternative options and cost-effective steps that can be taken in early life, those appropriate during middle life, and those required in late life. This paper briefly describes an approach designed to provide the plant owner a maximum of flexibility in developing a life extension plan

Two-step condensation of the ideal Bose gas in highly anisotropic traps

NARCIS (Netherlands)

van Druten, N.J.; Ketterle, W.

1997-01-01

The ideal Bose gas in a highly anisotropic harmonic potential is studied. It is found that Bose-Einstein condensation occurs in two distinct steps as the temperature is lowered. In the first step the specific heat shows a sharp feature, but the system still occupies many one-dimensional quantum

Temporomandibular joint formation requires two distinct hedgehog-dependent steps.

Science.gov (United States)

Purcell, Patricia; Joo, Brian W; Hu, Jimmy K; Tran, Pamela V; Calicchio, Monica L; O'Connell, Daniel J; Maas, Richard L; Tabin, Clifford J

2009-10-27

We conducted a genetic analysis of the developing temporo-mandibular or temporomandi-bular joint (TMJ), a highly specialized synovial joint that permits movement and function of the mammalian jaw. First, we used laser capture microdissection to perform a genome-wide expression analysis of each of its developing components. The expression patterns of genes identified in this screen were examined in the TMJ and compared with those of other synovial joints, including the shoulder and the hip joints. Striking differences were noted, indicating that the TMJ forms via a distinct molecular program. Several components of the hedgehog (Hh) signaling pathway are among the genes identified in the screen, including Gli2, which is expressed specifically in the condyle and in the disk of the developing TMJ. We found that mice deficient in Gli2 display aberrant TMJ development such that the condyle loses its growth-plate-like cellular organization and no disk is formed. In addition, we used a conditional strategy to remove Smo, a positive effector of the Hh signaling pathway, from chondrocyte progenitors. This cell autonomous loss of Hh signaling allows for disk formation, but the resulting structure fails to separate from the condyle. Thus, these experiments establish that Hh signaling acts at two distinct steps in disk morphogenesis, condyle initiation, and disk-condyle separation and provide a molecular framework for future studies of the TMJ.

Development of in Silico Models for Predicting P-Glycoprotein Inhibitors Based on a Two-Step Approach for Feature Selection and Its Application to Chinese Herbal Medicine Screening.

Science.gov (United States)

Yang, Ming; Chen, Jialei; Shi, Xiufeng; Xu, Liwen; Xi, Zhijun; You, Lisha; An, Rui; Wang, Xinhong

2015-10-05

P-glycoprotein (P-gp) is regarded as an important factor in determining the ADMET (absorption, distribution, metabolism, elimination, and toxicity) characteristics of drugs and drug candidates. Successful prediction of P-gp inhibitors can thus lead to an improved understanding of the underlying mechanisms of both changes in the pharmacokinetics of drugs and drug-drug interactions. Therefore, there has been considerable interest in the development of in silico modeling of P-gp inhibitors in recent years. Considering that a large number of molecular descriptors are used to characterize diverse structural moleculars, efficient feature selection methods are required to extract the most informative predictors. In this work, we constructed an extensive available data set of 2428 molecules that includes 1518 P-gp inhibitors and 910 P-gp noninhibitors from multiple resources. Importantly, a two-step feature selection approach based on a genetic algorithm and a greedy forward-searching algorithm was employed to select the minimum set of the most informative descriptors that contribute to the prediction of P-gp inhibitors. To determine the best machine learning algorithm, 18 classifiers coupled with the feature selection method were compared. The top three best-performing models (flexible discriminant analysis, support vector machine, and random forest) and their ensemble model using respectively only 3, 9, 7, and 14 descriptors achieve an overall accuracy of 83.2%-86.7% for the training set containing 1040 compounds, an overall accuracy of 82.3%-85.5% for the test set containing 1039 compounds, and a prediction accuracy of 77.4%-79.9% for the external validation set containing 349 compounds. The models were further extensively validated by DrugBank database (1890 compounds). The proposed models are competitive with and in some cases better than other published models in terms of prediction accuracy and minimum number of descriptors. Applicability domain then was addressed

N-terminus of Cardiac Myosin Essential Light Chain Modulates Myosin Step-Size

Science.gov (United States)

Wang, Yihua; Ajtai, Katalin; Kazmierczak, Katarzyna; Szczesna-Cordary, Danuta; Burghardt, Thomas P.

2016-01-01

Muscle myosin cyclically hydrolyzes ATP to translate actin. Ventricular cardiac myosin (βmys) moves actin with three distinct unitary step-sizes resulting from its lever-arm rotation and with step-frequencies that are modulated in a myosin regulation mechanism. The lever-arm associated essential light chain (vELC) binds actin by its 43 residue N-terminal extension. Unitary steps were proposed to involve the vELC N-terminal extension with the 8 nm step engaging the vELC/actin bond facilitating an extra ~19 degrees of lever-arm rotation while the predominant 5 nm step forgoes vELC/actin binding. A minor 3 nm step is the unlikely conversion of the completed 5 to the 8 nm step. This hypothesis was tested using a 17 residue N-terminal truncated vELC in porcine βmys (Δ17βmys) and a 43 residue N-terminal truncated human vELC expressed in transgenic mouse heart (Δ43αmys). Step-size and step-frequency were measured using the Qdot motility assay. Both Δ17βmys and Δ43αmys had significantly increased 5 nm step-frequency and coincident loss in the 8 nm step-frequency compared to native proteins suggesting the vELC/actin interaction drives step-size preference. Step-size and step-frequency probability densities depend on the relative fraction of truncated vELC and relate linearly to pure myosin species concentrations in a mixture containing native vELC homodimer, two truncated vELCs in the modified homodimer, and one native and one truncated vELC in the heterodimer. Step-size and step-frequency, measured for native homodimer and at two or more known relative fractions of truncated vELC, are surmised for each pure species by using a new analytical method. PMID:26671638

Benchmarking Professional Development Practices across Youth-Serving Organizations: Implications for Extension

Science.gov (United States)

Garst, Barry A.; Baughman, Sarah; Franz, Nancy

2014-01-01

Examining traditional and contemporary professional development practices of youth-serving organizations can inform practices across Extension, particularly in light of the barriers that have been noted for effectively developing the professional competencies of Extension educators. With professional development systems changing quickly,…

Two-step synthesis of silver selenide semiconductor with a linear magnetoresistance effect

International Nuclear Information System (INIS)

Yang, Fengxia; Xiong, Shuangtao; Liu, Fengxian; Han, Chong; Zhang, Duanming; Xia, Zhengcai

2012-01-01

A two-step synthesis method for polycrystalline β-silver selenide (β-Ag 2 Se) was developed. In the first step, nanopowder was prepared using a chemical conversion method at room temperature. In the second step, the nanopowder was compressed and then the bulk Ag 2 Se was fabricated by the solid-state sintering process. The crystalline phase and morphology were examined. The results showed that β-Ag 2 Se was fast fabricated at room temperature. The dense polycrystalline Ag-rich Ag 2 Se was synthesized successfully at 450 °C for 0.5 h under Argon flow. For the polycrystalline, the electronic properties and transverse magnetoresistance (TMR) in a pulsed magnetic field were investigated. The samples displayed n-type semiconducting behaviors and a critical temperature with a broaden temperature range of 140–150 K. Also, it presented a positive and nearly linear dependence on magnetic field H at H ≥ H c (crossover field) ranging from 2 to 20 T. Moreover, the linear dependence of TMR at strong field was non-saturating up to 35 T. Combining with the observation of morphology, it is thought that this unusual TMR effect was caused by slightly excess Ag. This new synthesis method provided a potential route to synthesize nonstoichiometric silver selenide. (paper)

Comparative Effectiveness of Two Walking Interventions on Participation, Step Counts, and Health.

Science.gov (United States)

Smith-McLallen, Aaron; Heller, Debbie; Vernisi, Kristin; Gulick, Diana; Cruz, Samantha; Snyder, Richard L

2017-03-01

To (1) compare the effects of two worksite-based walking interventions on employee participation rates; (2) compare average daily step counts between conditions, and; (3) examine the effects of increases in average daily step counts on biometric and psychologic outcomes. We conducted a cluster-randomized trial in which six employer groups were randomly selected and randomly assigned to condition. Four manufacturing worksites and two office-based worksite served as the setting. A total of 474 employees from six employer groups were included. A standard walking program was compared to an enhanced program that included incentives, feedback, competitive challenges, and monthly wellness workshops. Walking was measured by self-reported daily step counts. Survey measures and biometric screenings were administered at baseline and 3, 6, and 9 months after baseline. Analysis used linear mixed models with repeated measures. During 9 months, participants in the enhanced condition averaged 726 more steps per day compared with those in the standard condition (p women (-2.1 lbs.), and reductions in body mass index (-0.41 men, -0.31 women). Higher step counts were also associated with improvements in mood, having more energy, and higher ratings of overall health. An enhanced walking program significantly increases participation rates and daily step counts, which were associated with weight loss and reductions in body mass index.

Are women positive for the One Step but negative for the Two Step screening tests for gestational diabetes at higher risk for adverse outcomes?

Science.gov (United States)

Caissutti, Claudia; Khalifeh, Adeeb; Saccone, Gabriele; Berghella, Vincenzo

2018-02-01

The aim of this study was to evaluate if women meeting criteria for gestational diabetes mellitus (GDM) by the One Step test as per International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria but not by other less strict criteria have adverse pregnancy outcomes compared with GDM-negative controls. The primary outcome was the incidence of macrosomia, defined as birthweight > 4000 g. Electronic databases were searched from their inception until May 2017. All studies identifying pregnant women negative at the Two Step test, but positive at the One Step test for IADPSG criteria were included. We excluded studies that randomized women to the One Step vs. the Two Step tests; studies that compared different criteria within the same screening method; randomized studies comparing treatments for GDM; and studies comparing incidence of GDM in women doing the One Step test vs. the Two Step test. Eight retrospective cohort studies, including 29 983 women, were included. Five study groups and four control groups were identified. The heterogeneity between the studies was high. Gestational hypertension, preeclampsia and large for gestational age, as well as in some analyses cesarean delivery, macrosomia and preterm birth, were significantly more frequent, and small for gestational age in some analyses significantly less frequent, in women GDM-positive by the One Step, but not the Two Step. Women meeting criteria for GDM by IADPSG criteria but not by other less strict criteria have an increased risk of adverse pregnancy outcomes such as gestational hypertension, preeclampsia and large for gestational age, compared with GDM-negative controls. Based on these findings, and evidence from other studies that treatment decreases these adverse outcomes, we suggest screening for GDM using the One Step IADPSG criteria. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Interdisciplinary Professional Development Needs of Cooperative Extension Field Educators

Science.gov (United States)

Sondgerath, Travis

2016-01-01

The study discussed in this article sought to identify cross-program professional development needs of county-based Extension professionals (field educators). The study instrument was completed by 105 county-based Extension professionals. Interdisciplinary topics, such as program evaluation and volunteer management, were identified as subjects of…

Ehrenfest's theorem and the validity of the two-step model for strong-field ionization

DEFF Research Database (Denmark)

Shvetsov-Shilovskiy, Nikolay; Dimitrovski, Darko; Madsen, Lars Bojer

By comparison with the solution of the time-dependent Schrodinger equation we explore the validity of the two-step semiclassical model for strong-field ionization in elliptically polarized laser pulses. We find that the discrepancy between the two-step model and the quantum theory correlates...

Cyclic deformation behaviour of quenched and tempered AISI 4140 at two-step tensile-compressive-loading

Energy Technology Data Exchange (ETDEWEB)

Schulze, V.; Lang, K.-H.; Voehringer, O.; Macherauch, E. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Werkstoffkunde 1

1997-08-30

The cyclic deformation behaviour in stress-controlled two-step experiments with one or more changes between two blocks of certain lengths and amplitudes was investigated at the technically important steel AISI 4140 (German grade 42 CrMo 4). In all two-step experiments cyclic worksoftening behaviour is found. The degree of work softening is discussed in comparison to single-step experiments. In several cases effects of static strain-ageing can be found. (orig.) 10 refs.

Lessons from a Train-the-Trainer Professional Development Program: The Sustainable Trainer Engagement Program (STEP)

Science.gov (United States)

Shupla, Christine; Gladney, Alicia; Dalton, Heather; LaConte, Keliann; Truxillo, Jeannette; Shipp, Stephanie

2015-11-01

The Sustainable Trainer Engagement Program (STEP) is a modified train-the-trainer professional development program being conducted by the Lunar and Planetary Institute (LPI). STEP has provided two cohorts of 6-8th grade science specialists and lead teachers in the Houston region with in-depth Earth and Space Science (ESS) content, activities, and pedagogy over 15 days each, aligned with Texas science standards. This project has two over-arching goals: to improve middle school ESS instruction, and to create and test an innovative model for Train-the-Trainer.This poster will share details regarding STEP’s activities and resources, program achievements, and its main findings to date. STEP is being evaluated by external evaluators at the Research Institute of Texas, part of the Harris County Department of Education. External evaluation shows an increase after one year in STEP participants’ knowledge (cohort 1 showed a 10% increase; cohort 2 showed a 20% increase), confidence in teaching Earth and Space Science effectively (cohort 1 demonstrated a 10% increase; cohort 2 showed a 20% increase), and confidence in preparing other teachers (cohort 1 demonstrated a 12% increase; cohort 2 showed a 20% increase). By September 2015, STEP participants led (or assisted in leading) approximately 40 workshops for about 1800 science teachers in Texas. Surveys of teachers attending professional development conducted by STEP participants show very positive responses, with averages for conference workshop evaluations ranging from 3.6 on a 4 point scale, and other evaluations averaging from 4.1 to 5.0 on a 5 point scale.Main lessons for the team on the train-the-trainer model include: a lack of confidence by leaders in K-12 science education in presenting ESS professional development, difficulties in arranging for school or district content-specific professional development, the minimal duration of most school and district professional development sessions, and uncertainties in

Enrolling Advisers in Governing Privatised Agricultural Extension in Australia: Challenges and Opportunities for the Research, Development and Extension System

Science.gov (United States)

Paschen, Jana-Axinja; Reichelt, Nicole; King, Barbara; Ayre, Margaret; Nettle, Ruth

2017-01-01

Purpose: Current developments in the Australian agricultural research, development and extension (RD&E) system exemplify the complex governance challenges arising from the international privatisation of agricultural extension. Presenting early challenges emerging from a multi-stakeholder project aimed at stimulating the role of the private…

Adiabatic tapered optical fiber fabrication in two step etching

Science.gov (United States)

Chenari, Z.; Latifi, H.; Ghamari, S.; Hashemi, R. S.; Doroodmand, F.

2016-01-01

A two-step etching method using HF acid and Buffered HF is proposed to fabricate adiabatic biconical optical fiber tapers. Due to the fact that the etching rate in second step is almost 3 times slower than the previous droplet etching method, terminating the fabrication process is controllable enough to achieve a desirable fiber diameter. By monitoring transmitted spectrum, final diameter and adiabaticity of tapers are deduced. Tapers with losses about 0.3 dB in air and 4.2 dB in water are produced. The biconical fiber taper fabricated using this method is used to excite whispering gallery modes (WGMs) on a microsphere surface in an aquatic environment. So that they are suitable to be used in applications like WGM biosensors.

Production of Biodiesel from Acid Oil via a Two-Step Enzymatic Transesterification.

Science.gov (United States)

Choi, Nakyung; Lee, Jeom-Sig; Kwak, Jieun; Lee, Junsoo; Kim, In-Hwan

2016-11-01

A two-step enzymatic transesterification process in a solvent-free system has been developed as a novel approach to the production of biodiesel using acid oil from rice bran oil soapstock. The acid oil consisted of 53.7 wt% fatty acids, 2.4 wt% monoacylglycerols, 9.1 wt% diacylglycerols, 28.8 wt% triacylglycerols, and 6.0 wt% others. Three immobilized lipases were evaluated as potential biocatalysts, including Novozym 435 from Candida antarctica, Lipozyme RM IM from Rhizomucor miehei, and Lipozyme TL IM from Thermomyces lanuginosus. The effects of molar ratio of acid oil to ethanol, temperature, and enzyme loading were investigated to determine the optimum conditions for the transesterification with the three immobilized lipases. The optimum conditions of the three immobilized lipases were a molar ratio of 1:5 (acid oil to ethanol), the temperature range of 30-40°C, and the enzyme loading range of 5-10%. The two-step transesterification was then conducted under the optimum conditions of each lipase. The stepwise use of Novozym 435 and Lipozyme TL IM or Lipozyme RM IM and Lipozyme TL IM resulted in similar or higher levels of yield to the individual lipases. The maximum yields obtained in both stepwise uses were ca. 92%.

Rapid one-step selection method for generating nucleic acid aptamers: development of a DNA aptamer against α-bungarotoxin.

Directory of Open Access Journals (Sweden)

Lasse H Lauridsen

Full Text Available BACKGROUND: Nucleic acids based therapeutic approaches have gained significant interest in recent years towards the development of therapeutics against many diseases. Recently, research on aptamers led to the marketing of Macugen®, an inhibitor of vascular endothelial growth factor (VEGF for the treatment of age related macular degeneration (AMD. Aptamer technology may prove useful as a therapeutic alternative against an array of human maladies. Considering the increased interest in aptamer technology globally that rival antibody mediated therapeutic approaches, a simplified selection, possibly in one-step, technique is required for developing aptamers in limited time period. PRINCIPAL FINDINGS: Herein, we present a simple one-step selection of DNA aptamers against α-bungarotoxin. A toxin immobilized glass coverslip was subjected to nucleic acid pool binding and extensive washing followed by PCR enrichment of the selected aptamers. One round of selection successfully identified a DNA aptamer sequence with a binding affinity of 7.58 µM. CONCLUSION: We have demonstrated a one-step method for rapid production of nucleic acid aptamers. Although the reported binding affinity is in the low micromolar range, we believe that this could be further improved by using larger targets, increasing the stringency of selection and also by combining a capillary electrophoresis separation prior to the one-step selection. Furthermore, the method presented here is a user-friendly, cheap and an easy way of deriving an aptamer unlike the time consuming conventional SELEX-based approach. The most important application of this method is that chemically-modified nucleic acid libraries can also be used for aptamer selection as it requires only one enzymatic step. This method could equally be suitable for developing RNA aptamers.

Ultrasonic transesterification of Jatrophacurcas L. oil to biodiesel by a two-step process

Energy Technology Data Exchange (ETDEWEB)

Deng, Xin; Fang, Zhen; Liu, Yun-hu [Biomass Group, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 88 Xuefulu, Kunming, Yunnan Province 650223 (China)

2010-12-15

Transesterification of high free fatty acid content Jatropha oil with methanol to biodiesel catalyzed directly by NaOH and high-concentrated H{sub 2}SO{sub 4} or by two-step process were studied in an ultrasonic reactor at 60 C. If NaOH was used as catalyst, biodiesel yield was only 47.2% with saponification problem. With H{sub 2}SO{sub 4} as catalyst, biodiesel yield was increased to 92.8%. However, longer reaction time (4 h) was needed and the biodiesel was not stable. A two-step, acid-esterification and base-transesterification process was further used for biodiesel production. It was found that after the first-step pretreatment with H{sub 2}SO{sub 4} for 1 h, the acid value of Jatropha oil was reduced from 10.45 to 1.2 mg KOH/g, and subsequently, NaOH was used for the second-step transesterification. Stable and clear yellowish biodiesel was obtained with 96.4% yield after reaction for 0.5 h. The total production time was only 1.5 h that is just half of the previous reported. The two-step process with ultrasonic radiation is effective and time-saving for biodiesel production from Jatropha oil. (author)

Ultrasonic transesterification of Jatrophacurcas L. oil to biodiesel by a two-step process

Energy Technology Data Exchange (ETDEWEB)

Deng Xin [Biomass Group, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 88 Xuefulu, Kunming, Yunnan Province 650223 (China); Fang Zhen, E-mail: zhenfang@xtbg.ac.c [Biomass Group, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 88 Xuefulu, Kunming, Yunnan Province 650223 (China); Liu Yunhu [Biomass Group, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 88 Xuefulu, Kunming, Yunnan Province 650223 (China)

2010-12-15

Transesterification of high free fatty acid content Jatropha oil with methanol to biodiesel catalyzed directly by NaOH and high-concentrated H{sub 2}SO{sub 4} or by two-step process were studied in an ultrasonic reactor at 60 deg. C. If NaOH was used as catalyst, biodiesel yield was only 47.2% with saponification problem. With H{sub 2}SO{sub 4} as catalyst, biodiesel yield was increased to 92.8%. However, longer reaction time (4 h) was needed and the biodiesel was not stable. A two-step, acid-esterification and base-transesterification process was further used for biodiesel production. It was found that after the first-step pretreatment with H{sub 2}SO{sub 4} for 1 h, the acid value of Jatropha oil was reduced from 10.45 to 1.2 mg KOH/g, and subsequently, NaOH was used for the second-step transesterification. Stable and clear yellowish biodiesel was obtained with 96.4% yield after reaction for 0.5 h. The total production time was only 1.5 h that is just half of the previous reported. The two-step process with ultrasonic radiation is effective and time-saving for biodiesel production from Jatropha oil.

Two-step flash light sintering process for crack-free inkjet-printed Ag films

International Nuclear Information System (INIS)

Park, Sung-Hyeon; Kim, Hak-Sung; Jang, Shin; Lee, Dong-Jun; Oh, Jehoon

2013-01-01

In this paper, a two-step flash light sintering process for inkjet-printed Ag films is investigated with the aim of improving the quality of sintered Ag films. The flash light sintering process is divided into two steps: a preheating step and a main sintering step. The preheating step is used to remove the organic binder without abrupt vaporization. The main sintering step is used to complete the necking connections among the silver nanoparticles and achieve high electrical conductivity. The process minimizes the damage on the polymer substrate and the interface between the sintered Ag film and polymer substrate. The electrical conductivity is calculated by measuring the resistance and cross-sectional area with an LCR meter and 3D optical profiler, respectively. It is found that the resistivity of the optimal flash light-sintered Ag films (36.32 nΩ m), which is 228.86% of that of bulk silver, is lower than that of thermally sintered ones (40.84 nΩ m). Additionally, the polyimide film used as the substrate is preserved with the inkjet-printed pattern shape during the flash light sintering process without delamination or defects. (paper)

The design of a real-time formative evaluation of the implementation process of lifestyle interventions at two worksites using a 7-step strategy (BRAVO@Work).

Science.gov (United States)

Wierenga, Debbie; Engbers, Luuk H; van Empelen, Pepijn; Hildebrandt, Vincent H; van Mechelen, Willem

2012-08-07

Worksite health promotion programs (WHPPs) offer an attractive opportunity to improve the lifestyle of employees. Nevertheless, broad scale and successful implementation of WHPPs in daily practice often fails. In the present study, called BRAVO@Work, a 7-step implementation strategy was used to develop, implement and embed a WHPP in two different worksites with a focus on multiple lifestyle interventions.This article describes the design and framework for the formative evaluation of this 7-step strategy under real-time conditions by an embedded scientist with the purpose to gain insight into whether this this 7-step strategy is a useful and effective implementation strategy. Furthermore, we aim to gain insight into factors that either facilitate or hamper the implementation process, the quality of the implemented lifestyle interventions and the degree of adoption, implementation and continuation of these interventions. This study is a formative evaluation within two different worksites with an embedded scientist on site to continuously monitor the implementation process. Each worksite (i.e. a University of Applied Sciences and an Academic Hospital) will assign a participating faculty or a department, to implement a WHPP focusing on lifestyle interventions using the 7-step strategy. The primary focus will be to describe the natural course of development, implementation and maintenance of a WHPP by studying [a] the use and adherence to the 7-step strategy, [b] barriers and facilitators that influence the natural course of adoption, implementation and maintenance, and [c] the implementation process of the lifestyle interventions. All data will be collected using qualitative (i.e. real-time monitoring and semi-structured interviews) and quantitative methods (i.e. process evaluation questionnaires) applying data triangulation. Except for the real-time monitoring, the data collection will take place at baseline and after 6, 12 and 18 months. This is one of the few

The design of a real-time formative evaluation of the implementation process of lifestyle interventions at two worksites using a 7-step strategy (BRAVO@Work

Directory of Open Access Journals (Sweden)

Wierenga Debbie

2012-08-01

Full Text Available Abstract Background Worksite health promotion programs (WHPPs offer an attractive opportunity to improve the lifestyle of employees. Nevertheless, broad scale and successful implementation of WHPPs in daily practice often fails. In the present study, called BRAVO@Work, a 7-step implementation strategy was used to develop, implement and embed a WHPP in two different worksites with a focus on multiple lifestyle interventions. This article describes the design and framework for the formative evaluation of this 7-step strategy under real-time conditions by an embedded scientist with the purpose to gain insight into whether this this 7-step strategy is a useful and effective implementation strategy. Furthermore, we aim to gain insight into factors that either facilitate or hamper the implementation process, the quality of the implemented lifestyle interventions and the degree of adoption, implementation and continuation of these interventions. Methods and design This study is a formative evaluation within two different worksites with an embedded scientist on site to continuously monitor the implementation process. Each worksite (i.e. a University of Applied Sciences and an Academic Hospital will assign a participating faculty or a department, to implement a WHPP focusing on lifestyle interventions using the 7-step strategy. The primary focus will be to describe the natural course of development, implementation and maintenance of a WHPP by studying [a] the use and adherence to the 7-step strategy, [b] barriers and facilitators that influence the natural course of adoption, implementation and maintenance, and [c] the implementation process of the lifestyle interventions. All data will be collected using qualitative (i.e. real-time monitoring and semi-structured interviews and quantitative methods (i.e. process evaluation questionnaires applying data triangulation. Except for the real-time monitoring, the data collection will take place at baseline and

Effect of bur-cut dentin on bond strength using two all-in-one and one two-step adhesive systems.

Science.gov (United States)

Koase, Kaori; Inoue, Satoshi; Noda, Mamoru; Tanaka, Toru; Kawamoto, Chiharu; Takahashi, Akiko; Nakaoki, Yasuko; Sano, Hidehiko

2004-01-01

To compare the microtensile bond strength (MTBS) of two all-in-one adhesive systems and one experimental two-step self-etching adhesive system to two types of bur-cut dentin. Using one of the three adhesives, Xeno CF Bond (Xeno), Prompt L-Pop (PL), or the experimental two-step system ABF (ABF), resin composite was bonded to flat buccal and root dentin surfaces of eight extracted human premolars. These surfaces were produced using either regular-grit or superfine-grit diamond burs. After storage overnight in 37 degrees C water, the bonded specimens were sectioned into six or seven slices approximately 0.7 mm thick perpendicular to the bonded surface. They were then subjected to microtensile testing. The surfaces of the fractured specimens were observed microscopically to determine the failure mode. In addition, to observe the effect of conditioning, the two types of bur-cut dentin surfaces were conditioned with the adhesives, rinsed with acetone, and observed with SEM. When Xeno and PL were bonded to dentin cut with a regular-grit diamond bur, MTBS values were lower than to superfine bur-cut dentin, and failures occurred adhesively at the interface, whereas the experimental two-step adhesive showed no significant difference in microtensile bond strength between two differently cut surfaces. The all-in-one adhesives tested here improved bond strengths when bonded to superfine bur-cut dentin as a substrate, whereas the experimental two-step adhesive system showed unchanged bonding to both regular and superfine bur-cut dentin surfaces.

Design, fabrication and characterization of a two-step released silicon dioxide piezoresistive microcantilever immunosensor

International Nuclear Information System (INIS)

Zhou, Youzheng; Wang, Zheyao; Wang, Chaonan; Ruan, Wenzhou; Liu, Litian

2009-01-01

This paper presents the design, fabrication and characterization of a silicon dioxide piezoresistive microcantilever immunosensor fabricated on silicon-on-insulator (SOI) wafers. The microcantilever consists of two strips of single crystalline silicon piezoresistors sandwiched in between two silicon dioxide layers. A theoretical model for the laminated microcantilever with a discontinuous layer is deduced using classic laminated beam theory. A two-step release method combining anisotropic and isotropic etching is developed to suspend the microcantilever, and the fabrication results show an excellent yield. The residual stress-induced free bending of the microcantilever and the stress caused by self-heating of the piezoresistors are discussed. The microcantilever sensor is characterized as an immunosensor using specific binding of antigen and antibody. These methods and some conclusions are also applicable to the development of other piezoresistive sensors that use laminated structures

Core-shell polymer nanorods by a two-step template wetting process

International Nuclear Information System (INIS)

Dougherty, S; Liang, J

2009-01-01

One-dimensional core-shell polymer nanowires offer many advantages and great potential for many different applications. In this paper we introduce a highly versatile two-step template wetting process to fabricate two-component core-shell polymer nanowires with controllable shell thickness. PLLA and PMMA were chosen as model polymers to demonstrate the feasibility of this process. Solution wetting with different concentrations of polymer solutions was used to fabricate the shell layer and melt wetting was used to fill the shell with the core polymer. The shell thickness was analyzed as a function of the polymer solution concentration and viscosity, and the core-shell morphology was observed with TEM. This paper demonstrates the feasibility of fabricating polymer core-shell nanostructures using our two-step template wetting process and opens the arena for optimization and future experiments with polymers that are desirable for specific applications.

Two-step laser ionization schemes for in-gas laser ionization and spectroscopy of radioactive isotopesa

OpenAIRE

Kudryavtsev, Yuri; Ferrer, Rafael; Huyse, Mark; Van den Bergh, Paul; Van Duppen, Piet; Vermeeren, L.

2014-01-01

The in-gas laser ionization and spectroscopy technique has been developed at the Leuven isotope separator on-line facility for the production and in-source laser spectroscopy studies of short-lived radioactive isotopes. In this article, results from a study to identify efficient optical schemes for the two-step resonance laser ionization of 18 elements are presented. © 2013 AIP Publishing LLC.

Voluntary movement frequencies in submaximal one- and two-legged knee extension exercise and pedaling

Directory of Open Access Journals (Sweden)

Julie Sørbø Stang

2016-02-01

Full Text Available Understanding of behavior and control of human voluntary rhythmic stereotyped leg movements is useful in work to improve performance, function, and rehabilitation of exercising, healthy, and injured humans. The present study aimed at adding to the existing understanding within this field. To pursue the aim, correlations between freely chosen movement frequencies in relatively simple, single-joint, one- and two-legged knee extension exercise were investigated. The same was done for more complex, multiple-joint, one- and two-legged pedaling. These particular activities were chosen because they could be considered related to some extent, as they shared a key aspect of knee extension, and because they at the same time were different. The activities were performed at submaximal intensities, by healthy individuals (n=16, thereof 8 women; 23.4±2.7 years; 1.70±0.11 m; 68.6±11.2 kg.High and fair correlations (R-values of 0.99 and 0.75 occurred between frequencies generated with the dominant leg and the nondominant leg during knee extension exercise and pedaling, respectively. Fair to high correlations (R-values between 0.71 and 0.95 occurred between frequencies performed with each of the two legs in an activity, and the two-legged frequency performed in the same type of activity. In general, the correlations were higher for knee extension exercise than for pedaling. Correlations between knee extension and pedaling frequencies were of modest occurrence.The correlations between movement frequencies generated separately by each of the legs might be interpreted to support the following working hypothesis, which was based on existing literature. It is likely that involved central pattern generators (CPGs of the two legs share a common frequency generator or that separate frequency generators of each leg are attuned via interneuronal connections. Further, activity type appeared to be relevant. Thus, the apparent common rhythmogenesis for the two legs

ChromAlign: A two-step algorithmic procedure for time alignment of three-dimensional LC-MS chromatographic surfaces.

Science.gov (United States)

Sadygov, Rovshan G; Maroto, Fernando Martin; Hühmer, Andreas F R

2006-12-15

We present an algorithmic approach to align three-dimensional chromatographic surfaces of LC-MS data of complex mixture samples. The approach consists of two steps. In the first step, we prealign chromatographic profiles: two-dimensional projections of chromatographic surfaces. This is accomplished by correlation analysis using fast Fourier transforms. In this step, a temporal offset that maximizes the overlap and dot product between two chromatographic profiles is determined. In the second step, the algorithm generates correlation matrix elements between full mass scans of the reference and sample chromatographic surfaces. The temporal offset from the first step indicates a range of the mass scans that are possibly correlated, then the correlation matrix is calculated only for these mass scans. The correlation matrix carries information on highly correlated scans, but it does not itself determine the scan or time alignment. Alignment is determined as a path in the correlation matrix that maximizes the sum of the correlation matrix elements. The computational complexity of the optimal path generation problem is reduced by the use of dynamic programming. The program produces time-aligned surfaces. The use of the temporal offset from the first step in the second step reduces the computation time for generating the correlation matrix and speeds up the process. The algorithm has been implemented in a program, ChromAlign, developed in C++ language for the .NET2 environment in WINDOWS XP. In this work, we demonstrate the applications of ChromAlign to alignment of LC-MS surfaces of several datasets: a mixture of known proteins, samples from digests of surface proteins of T-cells, and samples prepared from digests of cerebrospinal fluid. ChromAlign accurately aligns the LC-MS surfaces we studied. In these examples, we discuss various aspects of the alignment by ChromAlign, such as constant time axis shifts and warping of chromatographic surfaces.

Developing a Marketing Mind-Set: Training and Mentoring for County Extension Employees

Science.gov (United States)

Sneed, Christopher T.; Elizer, Amy Hastings; Hastings, Shirley; Barry, Michael

2016-01-01

Marketing the county Extension program is a critical responsibility of the entire county staff. This article describes a unique peer-to-peer training and mentoring program developed to assist county Extension staff in improving marketing skills and successfully developing and implementing a county Extension marketing plan. Data demonstrating…

Two-step flash light sintering of copper nanoparticle ink to remove substrate warping

Energy Technology Data Exchange (ETDEWEB)

Ryu, Chung-Hyeon; Joo, Sung-Jun [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul, 133-791 (Korea, Republic of)

2016-10-30

Highlights: • We performed the two-step flash light sintering for copper nanoparticle ink to remove substrate warping. • 12 J/cm{sup 2} of preheating and 7 J/cm{sup 2} of main sintering energies were determined as optimum conditions to sinter the copper nanoparticle ink. • The resistivity of two-step sintered copper nanoparticle ink was 3.81 μΩ cm with 5B adhesion level, 2.3 times greater than that of bulk copper. • The two-step sintered case showed a high conductivity without any substrate warping. - Abstract: A two-step flash light sintering process was devised to reduce the warping of polymer substrates during the sintering of copper nanoparticle ink. To determine the optimum sintering conditions of the copper nanoparticle ink, the flash light irradiation conditions (pulse power, pulse number, on-time, and off-time) were varied and optimized. In order to monitor the flash light sintering process, in situ resistance and temperature monitoring of copper nanoink were conducted during the flash light sintering process. Also, a transient heat transfer analysis was performed by using the finite-element program ABAQUS to predict the temperature changes of copper nanoink and polymer substrate. The microstructures of the sintered copper nanoink films were analyzed by scanning electron microscopy. Additionally, an X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize the crystal phase change of the sintered copper nanoparticles. The resulting two-step flash light sintered copper nanoink films exhibited a low resistivity (3.81 μΩ cm, 2.3 times of that of bulk copper) and 5B level of adhesion strength without warping of the polymer substrate.

Development of a novel and customizable two-solution mixing type spray nozzle for one-step preparation of nanoparticle-containing microparticles.

Science.gov (United States)

Ozeki, Tetsuya; Akiyama, Yusuke; Takahashi, Norimitsu; Tagami, Tatsuaki; Tanaka, Toshiyuki; Fujii, Masashi; Okada, Hiroaki

2012-01-01

Production of drug nanoparticles is an effective strategy to enhance solubility and oral absorption of water-insoluble drugs. The handling of drug nanoparticles has been an important issue in drug formulation because nanoparticles easily aggregate each other and redispersion of these particles is very difficult. In the present study, we developed a unique two-solution mixing type spray nozzle that can prepare drug nanoparticles in microparticles in one step without any common solvent and surfactant, and then, the prepared formulation were evaluated. Ethylcellulose (EC) and mannitol (MAN) were used as a model polymer of water-insoluble compound and a water-soluble carrier, respectively. We characterized the EC/MAN microparticles produced by the novel spray nozzle when customizing the nozzle parts to mix EC and MAN solution. Relatively smaller EC nanoparticles (customizable parts in the nozzle. In addition, the core of EC nanoparticles (<50 nm) was also observed by atomic force microscopy. We also found that the mixing time in the nozzle parts affected the size and the standard deviation of EC nanoparticles. These results suggest that the size of EC nanoparticles in MAN microparticles is controllable by using this unique nozzle. After all, we could prepare MAN microparticles containing EC nanoparticles in one step by using the novel nozzle. The drug/MAN microparticles formulation produced by the nozzle may be useful for the handling of drug nanoparticles.

48 CFR 52.214-23 - Late submissions, modifications, revisions, and withdrawals of technical proposals under two-step...

Science.gov (United States)

2010-10-01

..., modifications, revisions, and withdrawals of technical proposals under two-step sealed bidding. 52.214-23... Late submissions, modifications, revisions, and withdrawals of technical proposals under two-step..., Modifications, Revisions, and Withdrawals of Technical Proposals Under Two-Step Sealed Bidding (NOV 1999) (a...

Two Extension Block Kirschner Wires’ Technique for Bony Mallet Thumb

Directory of Open Access Journals (Sweden)

Yutaka Mifune

2016-01-01

Full Text Available Mallet fingers with an avulsion fracture of the distal phalanx or rupture of the terminal tendon of the extensor mechanism is known as a common injury, while mallet thumb is very rare. In this paper, the case of a 19-year-old woman with a sprained left thumb sustained while playing basketball is presented. Plain radiographs and computed tomography revealed an avulsion fracture involving more than half of the articular surface at the base of the distal phalanx. Closed reduction and percutaneous fixation were performed using the two extension block Kirschner wires’ technique under digital block anesthesia. At 4 months postoperatively, the patient had achieved excellent results according to Crawford’s evaluation criteria and had no difficulties in working or playing basketball. Various conservative and operative treatment strategies have been reported for management of mallet thumb. We chose the two extension block Kirschner wires’ technique to minimize invasion of the extensor mechanism and nail bed and to stabilize the large fracture fragment.

First-step nucleation growth dependence of InAs/InGaAs/InP quantum dot formation in two-step growth

International Nuclear Information System (INIS)

Yin Zongyou; Tang Xiaohong; Deny, Sentosa; Chin, Mee Koy; Zhang Jixuan; Teng Jinghua; Du Anyan

2008-01-01

First-step nucleation growth has an important impact on the two-step growth of high-quality mid-infrared emissive InAs/InGaAs/InP quantum dots (QDs). It has been found that an optimized growth rate for first-step nucleation is critical for forming QDs with narrow size distribution, high dot density and high crystal quality. High growth temperature has an advantage in removing defects in the QDs formed, but the dot density will be reduced. Contrasting behavior in forming InAs QDs using metal-organic vapor phase epitaxy (MOVPE) by varying the input flux ratio of group-V versus group-III source (V/III ratio) in the first-step nucleation growth has been observed and investigated. High-density, 2.5 x 10 10 cm -2 , InAs QDs emitting at>2.15 μm have been formed with narrow size distribution, ∼1 nm standard deviation, by reducing the V/III ratio to zero in first-step nucleation growth

Ultralow-density SiO2 aerogels prepared by a two-step sol-gel process

International Nuclear Information System (INIS)

Wang Jue; Li Qing; Shen Jun; Zhou Bin; Chen Lingyan; Jiang; Weiyang

1996-01-01

Low density SiO 2 gels are prepared by a two-step sol-gel process from TEOS. The influence of various solution ratios on the gelation process is investigated. The comparative characterization of gels using different solvent, such as ethanol, acetone and methyl cyanide, is also given. The ultralow-density SiO 2 aerogels with density less than 10 kg/m 3 are prepared by CO 2 supercritical drying technique. The structure difference between SiO 2 aerogels prepared by conventional single-step process and the two-step process is also presented

Human exposure assessment for biocides in the EU development of step by step guidance and worked examples

NARCIS (Netherlands)

Gerritsen-Ebben, R.M.G.; Hemmen, J.J. van

2007-01-01

Directive 98/8/EC(1) concerns EU harmonisation of placing biocidal products on the market. In the present short paper the preliminary results of an ongoing project are presented in which step by step guidance on human exposure assessment with worked examples is developed. For all 23 biocidal product

Two step continuous method to synthesize colloidal spheroid gold nanorods.

Science.gov (United States)

Chandra, S; Doran, J; McCormack, S J

2015-12-01

This research investigated a two-step continuous process to synthesize colloidal suspension of spheroid gold nanorods. In the first step; gold precursor was reduced to seed-like particles in the presence of polyvinylpyrrolidone and ascorbic acid. In continuous second step; silver nitrate and alkaline sodium hydroxide produced various shape and size Au nanoparticles. The shape was manipulated through weight ratio of ascorbic acid to silver nitrate by varying silver nitrate concentration. The specific weight ratio of 1.35-1.75 grew spheroid gold nanorods of aspect ratio ∼1.85 to ∼2.2. Lower weight ratio of 0.5-1.1 formed spherical nanoparticle. The alkaline medium increased the yield of gold nanorods and reduced reaction time at room temperature. The synthesized gold nanorods retained their shape and size in ethanol. The surface plasmon resonance was red shifted by ∼5 nm due to higher refractive index of ethanol than water. Copyright © 2015 Elsevier Inc. All rights reserved.

Impact of first-step potential and time on the vertical growth of ZnO nanorods on ITO substrate by two-step electrochemical deposition

International Nuclear Information System (INIS)

Kim, Tae Gyoum; Jang, Jin-Tak; Ryu, Hyukhyun; Lee, Won-Jae

2013-01-01

Highlights: •We grew vertical ZnO nanorods on ITO substrate using a two-step continuous potential process. •The nucleation for the ZnO nanorods growth was changed by first-step potential and duration. •The vertical ZnO nanorods were well grown when first-step potential was −1.2 V and 10 s. -- Abstract: In this study, we analyzed the growth of ZnO nanorods on an ITO (indium doped tin oxide) substrate by electrochemical deposition using a two-step, continuous potential process. We examined the effect of changing the first-step potential as well as the first-step duration on the morphological, structural and optical properties of ZnO nanorods, measured via using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and photoluminescence (PL), respectively. As a result, vertical ZnO nanorods were grown on ITO substrate without the need for a template when the first-step potential was set to −1.2 V for a duration of 10 s, and the second-step potential was set to −0.7 V for a duration of 1190 s. The ZnO nanorods on this sample showed the highest XRD (0 0 2)/(1 0 0) peak intensity ratio and the highest PL near band edge emission to deep level emission peak intensity ratio (NBE/DLE). In this study, the nucleation for vertical ZnO nanorod growth on an ITO substrate was found to be affected by changes in the first-step potential and first-step duration

some generalized two-step block hybrid numerov method for solving ...

African Journals Online (AJOL)

Nwokem et al.

ABSTRACT. This paper proposes a class of generalized two-step Numerov methods, a block hybrid type for the direct solution of general second order ordinary differential equations. Both the main method and additional methods were derived via interpolation and collocation procedures. The basic properties of zero ...

A novel two-step method for screening shade tolerant mutant plants via dwarfism

Directory of Open Access Journals (Sweden)

Wei Li

2016-10-01

Full Text Available When subjected to shade, plants undergo rapid shoot elongation, which often makes them more prone to disease and mechanical damage. Shade-tolerant plants can be difficult to breed; however, they offer a substantial benefit over other varieties in low-light areas. Although perennial ryegrass (Lolium perenne L. is a popular species of turf grasses because of their good appearance and fast establishment, the plant normally does not perform well under shade conditions. It has been reported that, in turfgrass, induced dwarfism can enhance shade tolerance. Here we describe a two-step procedure for isolating shade tolerant mutants of perennial ryegrass by first screening for dominant dwarf mutants, and then screening dwarf plants for shade tolerance. The two-step screening process to isolate shade tolerant mutants can be done efficiently with limited space at early seedling stages, which enables quick and efficient isolation of shade tolerant mutants, and thus facilitates development of shade tolerant new cultivars of turfgrasses. Using the method, we isolated 136 dwarf mutants from 300,000 mutagenized seeds, with 65 being shade tolerant (0.022%. When screened directly for shade tolerance, we recovered only four mutants from a population of 150,000 (0.003% mutagenized seeds. One shade tolerant mutant, shadow-1, was characterized in detail. In addition to dwarfism, shadow-1 and its sexual progeny displayed high degrees of tolerance to both natural and artificial shade. We showed that endogenous gibberellin (GA content in shadow-1 was higher than wild-type controls, and shadow-1 was also partially GA insensitive. Our novel, simple and effective two-step screening method should be applicable to breeding shade tolerant cultivars of turfgrasses, ground covers, and other economically important crop plants that can be used under canopies of existing vegetation to increase productivity per unit area of land.

Two-step method for creating a gastric tube during laparoscopic-thoracoscopic Ivor-Lewis esophagectomy.

Science.gov (United States)

Liu, Yu; Li, Ji-Jia; Zu, Peng; Liu, Hong-Xu; Yu, Zhan-Wu; Ren, Yi

2017-12-07

To introduce a two-step method for creating a gastric tube during laparoscopic-thoracoscopic Ivor-Lewis esophagectomy and assess its clinical application. One hundred and twenty-two patients with middle or lower esophageal cancer who underwent laparoscopic-thoracoscopic Ivor-Lewis esophagectomy at Liaoning Cancer Hospital and Institute from March 2014 to March 2016 were included in this study, and divided into two groups based on the procedure used for creating a gastric tube. One group used a two-step method for creating a gastric tube, and the other group used the conventional method. The two groups were compared regarding the operating time, surgical complications, and number of stapler cartridges used. The mean operating time was significantly shorter in the two-step method group than in the conventional method group [238 (179-293) min vs 272 (189-347) min, P creating a gastric tube during laparoscopic-thoracoscopic Ivor-Lewis esophagectomy has the advantages of simple operation, minimal damage to the tubular stomach, and reduced use of stapler cartridges.

Rural Development And Agricultural Extension Administration In ...

African Journals Online (AJOL)

This paper reviewed the wide range of policies and approaches formulated and implemented to effect agricultural and rural development in Nigeria. The paper reveals that the common feature of all the strategies is the use of institutionalized agricultural extension service, devoted principally to augment smallholder ...

Rapid transformation of two libraries using Kotter's Eight Steps of Change.

Science.gov (United States)

Wheeler, Terrie R; Holmes, Kristi L

2017-07-01

Two new directors were each charged by their institutions to catalyze transformational change in their libraries and to develop dynamic and evolving information ecosystems ready for the information challenges of the future. The directors approached this transformational change using a strategic, forward-looking approach. This paper presents examples of actions that served as catalysts for change at the two libraries using Kotter's Eight Steps of Change as a framework. Small and large changes are critical for successfully transforming library services, resources, and personnel. Libraries are faced with incredible pressure to adapt to meet emerging and intensifying information needs on today's academic medical campuses. These pressures offer an opportunity for libraries to accelerate their evolution at the micro and macro levels. This commentary reports the expansion of new services and areas of support, enhancement of professional visibility of the libraries on their campuses, and overall, a more positive and productive environment at the respective institutions.

Barriers and Effective Educational Strategies to Develop Extension Agents' Professional Competencies

Science.gov (United States)

Lakai, Dona; Jayaratne, K. S. U.; Moore, Gary E.; Kistler, Mark J.

2012-01-01

The study reported here determined the barriers and effective educational strategies to develop Extension agents' professional competencies. This was a descriptive survey research conducted with a random sample of Extension agents. Increased workload and lack of time and funding were identified as the most constraining barriers of Extension agents…

Design innovations of the next-step spherical torus experiment and spherical torus development path

International Nuclear Information System (INIS)

Ono, M.; Kessel, C.; Peng, M.

2003-01-01

The spherical torus (ST) fusion energy development path is complementary to the tokamak burning plasma experiment such as ITER as it focuses toward the compact Component Test Facility (CTF) and higher toroidal beta regimes to improve the design of DEMO and a Power Plant. To support the ST development path, one option of a Next Step Spherical Torus (NSST) device is examined. NSST is a 'performance extension' (PE) stage ST with a plasma current of 5 - 10 MA, R = 1.5, B T ≤ 2.7 T with flexible physics capability to 1) Provide a sufficient physics basis for the design of the CTF, 2) Explore advanced operating scenarios with high bootstrap current fraction/high performance regimes, which can then be utilized by CTF, DEMO, and Power Plants, 3) Contribute to the general plasma/fusion science of high β toroidal plasmas. The NSST facility is designed to utilize the TFTR site to minimize the cost and time required for the construction. (author)

A Two-Step Theory of the Evolution of Human Thinking

Directory of Open Access Journals (Sweden)

Satne Glenda

2016-03-01

Full Text Available Social accounts of objective content, like the one advanced by Tomasello (2014, are traditionally challenged by an ‘essential tension’ (Hutto and Satne 2015. The tension is the following: while sociality is deemed to be at the basis of thinking, in order to explain sociality, some form of thinking seems to be necessarily presupposed. In this contribution I analyse Tomasello’s two-step theory of the evolution of human thinking vis-à-vis this challenge. While his theory is in principle suited to address it, I claim that the specifics of the first step and the notion of perspective that infuse it are problematic in this regard. I end by briefly sketching an alternative.

Using an isomorphic problem pair to learn introductory physics: Transferring from a two-step problem to a three-step problem

Directory of Open Access Journals (Sweden)

Shih-Yin Lin

2013-10-01

Full Text Available In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. 382 students from a calculus-based and an algebra-based introductory physics course were administered a quiz in the recitation in which they had to learn from a solved problem provided and take advantage of what they learned from it to solve another isomorphic problem (which we call the quiz problem. The solved problem provided has two subproblems while the quiz problem has three subproblems, which is known from previous research to be challenging for introductory students. In addition to the solved problem, students also received extra scaffolding supports that were intended to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. The data analysis suggests that students had great difficulty in transferring what they learned from a two-step problem to a three-step problem. Although most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem, they were not necessarily able to apply the principles correctly. We also conducted think-aloud interviews with six introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. The interviews suggest that students often superficially mapped the principles employed in the solved problem to the quiz problem without necessarily understanding the governing conditions underlying each principle and examining the applicability of the principle in the new situation in an in-depth manner. Findings suggest that more scaffolding is needed to help students in transferring from a two-step problem to a three-step problem and applying the physics principles appropriately. We outline a few

Using an isomorphic problem pair to learn introductory physics: Transferring from a two-step problem to a three-step problem

Science.gov (United States)

Lin, Shih-Yin; Singh, Chandralekha

2013-12-01

In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. 382 students from a calculus-based and an algebra-based introductory physics course were administered a quiz in the recitation in which they had to learn from a solved problem provided and take advantage of what they learned from it to solve another isomorphic problem (which we call the quiz problem). The solved problem provided has two subproblems while the quiz problem has three subproblems, which is known from previous research to be challenging for introductory students. In addition to the solved problem, students also received extra scaffolding supports that were intended to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. The data analysis suggests that students had great difficulty in transferring what they learned from a two-step problem to a three-step problem. Although most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem, they were not necessarily able to apply the principles correctly. We also conducted think-aloud interviews with six introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. The interviews suggest that students often superficially mapped the principles employed in the solved problem to the quiz problem without necessarily understanding the governing conditions underlying each principle and examining the applicability of the principle in the new situation in an in-depth manner. Findings suggest that more scaffolding is needed to help students in transferring from a two-step problem to a three-step problem and applying the physics principles appropriately. We outline a few possible strategies

Stress corrosion cracking resistance of aluminum alloy 7000 series after two-step aging

Directory of Open Access Journals (Sweden)

Jegdić Bore V.

2015-01-01

Full Text Available The effect of one step-and a new (short two-step aging on the resistance to stress corrosion cracking of an aluminum alloy 7000 series was investigated, using slow strain rate test and fracture mechanics method. Aging level in the tested alloy was evaluated by means of scanning electron microscopy and measurements of electrical resistivity. It was shown that the alloy after the new two-step aging is significantly more resistant to stress corrosion cracking. Values of tensile properties and fracture toughness are similar for both thermal states. Processes that take place at the crack tip have been considered. The effect of the testing solution temperature on the crack growth rate on the plateau was determined. Two values of the apparent activation energy were obtained. These values correspond to different processes that control crack growth rate on the plateau at higher and lower temperatures. [Projekat Ministarstva nauke Republike Srbije, br. TR 34028 i br. TR 34016

L.S. Vygotsky's Principle "One Step in Learning — A Hundred Steps in Development": In Search of Evidence

Directory of Open Access Journals (Sweden)

V.K. Zaretsky

2015-10-01

Full Text Available On the basis of L.S. Vygotsky's published works the paper attempts to trace the dynamics of his concepts of child development and to provide evidence supporting Vygotsky's statement that one step in learning equals a hundred in development, which is one of the key principles of culturalhistorical theory in its application to child development. This statement is put in a row with two other major principles: one arguing that learning precedes development and the other referring to the zone of proximal development. The paper outlines a multivector model of the zone of proximal development as one of the conceptual tools of the reflective and activity approach to helping children overcome learning difficulties and promoting their development. The paper also describes a case study in which an orphan child with a disability received psychological and educational support that obviously contributed to the child's development. It is argued that L.S. Vygotsky's idea of the specific relationship between learning and development has fundamental theoretical and practical implications, in particular, for working with children with special needs

Effect of two-step aging on the mechanical properties of AA2219 DC cast alloy

Energy Technology Data Exchange (ETDEWEB)

Elgallad, E.M., E-mail: eelgalla@uqac.ca; Zhang, Z.; Chen, X.-G.

2015-02-11

With its combination of high specific strength, good machinability and excellent weldability, AA2219 direct chill (DC) cast alloy has become a new category of materials for manufacturing large molds for the plastics and automotive industries. The effect of two-step aging on the microstructural evolution and mechanical properties of AA2219 DC cast alloy was investigated. The precipitate microstructure was characterized under different heat treatment conditions using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The poor mechanical properties of the air-quenched alloy were attributed to the presence of quench-induced coarse θ′ and θ precipitates, which had very limited contribution to the precipitation hardening during the aging treatment. The two-step aging treatment of the air-quenched AA2219 alloy involved the precipitation of GP zones in the first step followed by their transformation into fine θ″ strengthening precipitates in the second step, which considerably improved the mechanical properties. After undergoing 120 °C/36 h+190 °C/8 h two-step aging, the hardness, YS and UTS of the air-quenched alloy were increased by 27%, 46% and 15%, respectively, compared with 190 °C/8 h one-step aging.

Effectiveness of en masse versus two-step retraction: a systematic review and meta-analysis

Directory of Open Access Journals (Sweden)

Mumen Z. Rizk

2018-01-01

Full Text Available Abstract Background This review aims to compare the effectiveness of en masse and two-step retraction methods during orthodontic space closure regarding anchorage preservation and anterior segment retraction and to assess their effect on the duration of treatment and root resorption. Methods An electronic search for potentially eligible randomized controlled trials and prospective controlled trials was performed in five electronic databases up to July 2017. The process of study selection, data extraction, and quality assessment was performed by two reviewers independently. A narrative review is presented in addition to a quantitative synthesis of the pooled results where possible. The Cochrane risk of bias tool and the Newcastle-Ottawa Scale were used for the methodological quality assessment of the included studies. Results Eight studies were included in the qualitative synthesis in this review. Four studies were included in the quantitative synthesis. En masse/miniscrew combination showed a statistically significant standard mean difference regarding anchorage preservation − 2.55 mm (95% CI − 2.99 to − 2.11 and the amount of upper incisor retraction − 0.38 mm (95% CI − 0.70 to − 0.06 when compared to a two-step/conventional anchorage combination. Qualitative synthesis suggested that en masse retraction requires less time than two-step retraction with no difference in the amount of root resorption. Conclusions Both en masse and two-step retraction methods are effective during the space closure phase. The en masse/miniscrew combination is superior to the two-step/conventional anchorage combination with regard to anchorage preservation and amount of retraction. Limited evidence suggests that anchorage reinforcement with a headgear produces similar results with both retraction methods. Limited evidence also suggests that en masse retraction may require less time and that no significant differences exist in the amount of root

Microstructure and superconducting properties of Bi-2223/Ag tapes fabricated in the two-step sintering process

International Nuclear Information System (INIS)

Lu, X.Y.; Nagata, A.; Sugawara, K.

2008-01-01

The microstructure and superconducting properties of Bi-2223/Ag tapes fabricated in the two-step sintering process were investigated. The tapes were then subjected to two heat treatments with an intermediate rolling. All the tapes were sintered at 835 deg. C for 24 h at initial sintering stage. A two-step sintering procedure was then used in the final sintering stage. In the first step, the tapes are sintered at 840-865 deg. C for 1 h. In the second step, they were sintered at 835 deg. C for 120 h. The results show that the first step sintering temperature has significant influence on the microstructure and the critical current density J c . The observed microstructures are consistent well with the different J c performances of the tapes first-step-sintered at different temperatures. The tape first-step-sintered at 850 deg. C, which has small secondary phases, stronger c-axis grain alignment, higher proportion of Bi-2223 phase, and no cracks, exhibits the highest J c value

SPAR-H Step-by-Step Guidance

Energy Technology Data Exchange (ETDEWEB)

April M. Whaley; Dana L. Kelly; Ronald L. Boring; William J. Galyean

2012-06-01

Step-by-step guidance was developed recently at Idaho National Laboratory for the US Nuclear Regulatory Commission on the use of the Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method for quantifying Human Failure Events (HFEs). This work was done to address SPAR-H user needs, specifically requests for additional guidance on the proper application of various aspects of the methodology. This paper overviews the steps of the SPAR-H analysis process and highlights some of the most important insights gained during the development of the step-by-step directions. This supplemental guidance for analysts is applicable when plant-specific information is available, and goes beyond the general guidance provided in existing SPAR-H documentation. The steps highlighted in this paper are: Step-1, Categorizing the HFE as Diagnosis and/or Action; Step-2, Rate the Performance Shaping Factors; Step-3, Calculate PSF-Modified HEP; Step-4, Accounting for Dependence, and; Step-5, Minimum Value Cutoff.

Comparison of single-entry and double-entry two-step couple screening for cystic fibrosis carriers

NARCIS (Netherlands)

tenKate, LP; Verheij, JBGM; Wildhagen, MF; Hilderink, HBM; Kooij, L; Verzijl, JG; Habbema, JDF

1996-01-01

Both single-entry two-step (SETS) couple screening and double-entry two-step (DETS) couple screening have been recommended as methods to screen for cystic fibrosis gene carriers. In this paper we compare the expected results from both types of screening. In general, DETS results in a higher

Efficient Hydrolysis of Rice Straw into Xylose and Glucose by a Two-step Process

Directory of Open Access Journals (Sweden)

YAN Lu-lu

2016-07-01

Full Text Available The hydrolysis of rice straw into xylose and glucose in dilute sulfuric acid aqueous solution was studied with a two-step process in batch autoclave reactor. The results showed that compared with the traditional one-step acid hydrolysis, both xylose and glucose could be produced in high yields from rice straw by using the two-step acid hydrolysis process. The effects of reaction temperature, reaction time, the amount of rice straw and acid concentration on the hydrolysis of rice straw were systematically studied, and showed that except initial rice straw loading amount, the other parameters had remarkable influence on the products distribution and yields. In the first-step of the hydrolysis process, a high xylose yield of 162.6 g·kg-1 was obtained at 140℃ after 120 min reaction time. When the solid residues from the first step were subjected to a second-step hydrolysis, a glucose yield as high as 216.5 g·kg-1 could be achieved at 180℃ after 120 min. This work provides a promising strategy for the efficient and value-added utilization of agricultural wastes such as rice straw.

a Two-Step Classification Approach to Distinguishing Similar Objects in Mobile LIDAR Point Clouds

Science.gov (United States)

He, H.; Khoshelham, K.; Fraser, C.

2017-09-01

Nowadays, lidar is widely used in cultural heritage documentation, urban modeling, and driverless car technology for its fast and accurate 3D scanning ability. However, full exploitation of the potential of point cloud data for efficient and automatic object recognition remains elusive. Recently, feature-based methods have become very popular in object recognition on account of their good performance in capturing object details. Compared with global features describing the whole shape of the object, local features recording the fractional details are more discriminative and are applicable for object classes with considerable similarity. In this paper, we propose a two-step classification approach based on point feature histograms and the bag-of-features method for automatic recognition of similar objects in mobile lidar point clouds. Lamp post, street light and traffic sign are grouped as one category in the first-step classification for their inter similarity compared with tree and vehicle. A finer classification of the lamp post, street light and traffic sign based on the result of the first-step classification is implemented in the second step. The proposed two-step classification approach is shown to yield a considerable improvement over the conventional one-step classification approach.

Smoke regions extraction based on two steps segmentation and motion detection in early fire

Science.gov (United States)

Jian, Wenlin; Wu, Kaizhi; Yu, Zirong; Chen, Lijuan

2018-03-01

Aiming at the early problems of video-based smoke detection in fire video, this paper proposes a method to extract smoke suspected regions by combining two steps segmentation and motion characteristics. Early smoldering smoke can be seen as gray or gray-white regions. In the first stage, regions of interests (ROIs) with smoke are obtained by using two step segmentation methods. Then, suspected smoke regions are detected by combining the two step segmentation and motion detection. Finally, morphological processing is used for smoke regions extracting. The Otsu algorithm is used as segmentation method and the ViBe algorithm is used to detect the motion of smoke. The proposed method was tested on 6 test videos with smoke. The experimental results show the effectiveness of our proposed method over visual observation.

Association between the gait pattern characteristics of older people and their two-step test scores.

Science.gov (United States)

Kobayashi, Yoshiyuki; Ogata, Toru

2018-04-27

The Two-Step test is one of three official tests authorized by the Japanese Orthopedic Association to evaluate the risk of locomotive syndrome (a condition of reduced mobility caused by an impairment of the locomotive organs). It has been reported that the Two-Step test score has a good correlation with one's walking ability; however, its association with the gait pattern of older people during normal walking is still unknown. Therefore, this study aims to clarify the associations between the gait patterns of older people observed during normal walking and their Two-Step test scores. We analyzed the whole waveforms obtained from the lower-extremity joint angles and joint moments of 26 older people in various stages of locomotive syndrome using principal component analysis (PCA). The PCA was conducted using a 260 × 2424 input matrix constructed from the participants' time-normalized pelvic and right-lower-limb-joint angles along three axes (ten trials of 26 participants, 101 time points, 4 angles, 3 axes, and 2 variable types per trial). The Pearson product-moment correlation coefficient between the scores of the principal component vectors (PCVs) and the scores of the Two-Step test revealed that only one PCV (PCV 2) among the 61 obtained relevant PCVs is significantly related to the score of the Two-Step test. We therefore concluded that the joint angles and joint moments related to PCV 2-ankle plantar-flexion, ankle plantar-flexor moments during the late stance phase, ranges of motion and moments on the hip, knee, and ankle joints in the sagittal plane during the entire stance phase-are the motions associated with the Two-Step test.

A two-step annealing process for enhancing the ferroelectric properties of poly(vinylidene fluoride) (PVDF) devices

KAUST Repository

Park, Jihoon; Kurra, Narendra; AlMadhoun, M. N.; Odeh, Ihab N.; Alshareef, Husam N.

2015-01-01

We report a simple two-step annealing scheme for the fabrication of stable non-volatile memory devices employing poly(vinylidene fluoride) (PVDF) polymer thin-films. The proposed two-step annealing scheme comprises the crystallization

Two-step source tracing strategy of Yersinia pestis and its historical epidemiology in a specific region.

Directory of Open Access Journals (Sweden)

Yanfeng Yan

Full Text Available Source tracing of pathogens is critical for the control and prevention of infectious diseases. Genome sequencing by high throughput technologies is currently feasible and popular, leading to the burst of deciphered bacterial genome sequences. Utilizing the flooding genomic data for source tracing of pathogens in outbreaks is promising, and challenging as well. Here, we employed Yersinia pestis genomes from a plague outbreak at Xinghai county of China in 2009 as an example, to develop a simple two-step strategy for rapid source tracing of the outbreak. The first step was to define the phylogenetic position of the outbreak strains in a whole species tree, and the next step was to provide a detailed relationship across the outbreak strains and their suspected relatives. Through this strategy, we observed that the Xinghai plague outbreak was caused by Y. pestis that circulated in the local plague focus, where the majority of historical plague epidemics in the Qinghai-Tibet Plateau may originate from. The analytical strategy developed here will be of great help in fighting against the outbreaks of emerging infectious diseases, by pinpointing the source of pathogens rapidly with genomic epidemiological data and microbial forensics information.

Two-step bioleaching of copper and gold from discarded printed circuit boards (PCB).

Science.gov (United States)

Işıldar, Arda; van de Vossenberg, Jack; Rene, Eldon R; van Hullebusch, Eric D; Lens, Piet N L

2016-11-01

An effective strategy for environmentally sound biological recovery of copper and gold from discarded printed circuit boards (PCB) in a two-step bioleaching process was experimented. In the first step, chemolithotrophic acidophilic Acidithiobacillus ferrivorans and Acidithiobacillus thiooxidans were used. In the second step, cyanide-producing heterotrophic Pseudomonas fluorescens and Pseudomonas putida were used. Results showed that at a 1% pulp density (10g/L PCB concentration), 98.4% of the copper was bioleached by a mixture of A. ferrivorans and A. thiooxidans at pH 1.0-1.6 and ambient temperature (23±2°C) in 7days. A pure culture of P. putida (strain WCS361) produced 21.5 (±1.5)mg/L cyanide with 10g/L glycine as the substrate. This gold complexing agent was used in the subsequent bioleaching step using the Cu-leached (by A. ferrivorans and A. thiooxidans) PCB material, 44.0% of the gold was mobilized in alkaline conditions at pH 7.3-8.6, and 30°C in 2days. This study provided a proof-of-concept of a two-step approach in metal bioleaching from PCB, by bacterially produced lixiviants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Integrated concept development of next-step helical-axis advanced stellarators

Energy Technology Data Exchange (ETDEWEB)

Warmer, Felix

2016-04-13

shows that the total construction costs are of the same order for both concepts. One main goal of this work - consolidating the aforementioned aspects - is the assessment of the physics and engineering dimensions of an intermediate-step burning-plasma stellarator which may be desired to mitigate development risks on the way to commercial fusion. Therefore, two boundary cases for such a device are presented. A small fast-track option using mostly today's technology and a technologically more sophisticated DEMO-like device. There is about a factor two difference in the construction costs between those two boundary cases.

Rapid Two-Step Procedure for Large-Scale Purification of Pediocin-Like Bacteriocins and Other Cationic Antimicrobial Peptides from Complex Culture Medium

OpenAIRE

Uteng, Marianne; Hauge, Håvard Hildeng; Brondz, Ilia; Nissen-Meyer, Jon; Fimland, Gunnar

2002-01-01

A rapid and simple two-step procedure suitable for both small- and large-scale purification of pediocin-like bacteriocins and other cationic peptides has been developed. In the first step, the bacterial culture was applied directly on a cation-exchange column (1-ml cation exchanger per 100-ml cell culture). Bacteria and anionic compounds passed through the column, and cationic bacteriocins were subsequently eluted with 1 M NaCl. In the second step, the bacteriocin fraction was applied on a lo...

Honeycomb development on Alexander Island, glacial history of George VI Sound and palaeoclimatic implications (Two Step Cliffs/Mars Oasis, W Antarctica)

Science.gov (United States)

André, Marie-Françoise; Hall, Kevin

2005-02-01

Analysis of three generations of glacial deposits and of a range of geomorphic features including widespread honeycombs and tafonis at Two Step Cliffs/Mars Oasis (71°52‧S, 68°15‧W) provides new insights into the geomorphological evolution of West Antarctica, with special respect to alveolar weathering. At Two Step Terrace, indicators of the inherited character of cavernous weathering were found, such as 97% non-flaking and varnished backwalls, and 80% tafoni floors that are till-covered and/or sealed by lithobiontic coatings. Based on the NE predominant aspect of the alveolized boulder faces, tafoni initiation is attributed to coastal salt spray weathering by halite coming from the George VI Sound during the 6.5 ka BP open water period. The present-day activity of these inherited cavities is restricted to roof flaking attributed to a combination of processes involving thermal stresses. This 6.5 ka BP phase of coastal alveolization is the first step of a six-stage Holocene geomorphological scenario that includes alternatively phases of glacial advance or stationing, and phases of vegetal colonization and/or rock weathering and aeolian abrasion on the deglaciated outcrops. This geomorphic scenario is tentatively correlated with the available palaeoenvironmental record in the Antarctic Peninsula region, with two potential geomorphic indicators of the Holocene Optimum being identified: (1) clusters of centimetric honeycombs facing the sound (marine optimum at 6.5 ka BP); (2) salmon-pink lithobiontic coatings preserved inside cavities and at the boulder surface (terrestrial optimum at 4 3 ka BP).

The Use of an e-Learning System for Agricultural Extension: A Case Study of the Rural Development Administration, Korea

Science.gov (United States)

Park, Duk-Byeong; Cho, Yong-Been; Lee, Minsoo

2007-01-01

The study explores the e-learning system of the Computer-Based Agricultural Extension Program (CBAES) and examines the differences in user satisfaction and preferences between the two systems for Agricultural Education and Extension at the Rural Development Administration (RDA) in Korea. It also describes the architecture, services, user…

A two-step annealing process for enhancing the ferroelectric properties of poly(vinylidene fluoride) (PVDF) devices

KAUST Repository

Park, Jihoon

2015-01-01

We report a simple two-step annealing scheme for the fabrication of stable non-volatile memory devices employing poly(vinylidene fluoride) (PVDF) polymer thin-films. The proposed two-step annealing scheme comprises the crystallization of the ferroelectric gamma-phase during the first step and enhancement of the PVDF film dense morphology during the second step. Moreover, when we extended the processing time of the second step, we obtained good hysteresis curves down to 1 Hz, the first such report for ferroelectric PVDF films. The PVDF films also exhibit a coercive field of 113 MV m-1 and a ferroelectric polarization of 5.4 μC cm-2. © The Royal Society of Chemistry 2015.

Blastocyst utilization rates after continuous culture in two commercial single-step media: a prospective randomized study with sibling oocytes.

Science.gov (United States)

Sfontouris, Ioannis A; Kolibianakis, Efstratios M; Lainas, George T; Venetis, Christos A; Petsas, George K; Tarlatzis, Basil C; Lainas, Tryfon G

2017-10-01

The aim of this study is to determine whether blastocyst utilization rates are different after continuous culture in two different commercial single-step media. This is a paired randomized controlled trial with sibling oocytes conducted in infertility patients, aged ≤40 years with ≥10 oocytes retrieved assigned to blastocyst culture and transfer. Retrieved oocytes were randomly allocated to continuous culture in either Sage one-step medium (Origio) or Continuous Single Culture (CSC) medium (Irvine Scientific) without medium renewal up to day 5 post oocyte retrieval. Main outcome measure was the proportion of embryos suitable for clinical use (utilization rate). A total of 502 oocytes from 33 women were randomly allocated to continuous culture in either Sage one-step medium (n = 250) or CSC medium (n = 252). Fertilization was performed by either in vitro fertilization or intracytoplasmic sperm injection, and embryo transfers were performed on day 5. Two patients had all blastocysts frozen due to the occurrence of severe ovarian hyperstimulation syndrome. Fertilization and cleavage rates, as well as embryo quality on day 3, were similar in the two media. Blastocyst utilization rates (%, 95% CI) [55.4% (46.4-64.1) vs 54.7% (44.9-64.6), p = 0.717], blastocyst formation rates [53.6% (44.6-62.5) vs 51.9 (42.2-61.6), p = 0.755], and proportion of good quality blastocysts [36.8% (28.1-45.4) vs 36.1% (27.2-45.0), p = 0.850] were similar in Sage one-step and CSC media, respectively. Continuous culture of embryos in Sage one-step and CSC media is associated with similar blastocyst development and utilization rates. Both single-step media appear to provide adequate support during in vitro preimplantation embryo development. Whether these observations are also valid for other continuous single medium protocols remains to be determined. NCT02302638.

Xylose Isomerization with Zeolites in a Two-Step Alcohol–Water Process

DEFF Research Database (Denmark)

Paniagua, Marta; Shunmugavel, Saravanamurugan; Melián Rodriguez, Mayra

2015-01-01

Isomerization of xylose to xylulose was efficiently catalyzed by large-pore zeolites in a two-step methanol–water process that enhanced the product yield significantly. The reaction pathway involves xylose isomerization to xylulose, which, in part, subsequently reacts with methanol to form methyl...

Next-Step Spherical Torus Experiment and Spherical Torus Strategy in the Fusion Energy Development Path

International Nuclear Information System (INIS)

Ono, M.; Peng, M.; Kessel, C.; Neumeyer, C.; Schmidt, J.; Chrzanowski, J.; Darrow, D.; Grisham, L.; Heitzenroeder, P.; Jarboe, T.; Jun, C.; Kaye, S.; Menard, J.; Raman, R.; Stevenson, T.; Viola, M.; Wilson, J.; Woolley, R.; Zatz, I.

2003-01-01

A spherical torus (ST) fusion energy development path which is complementary to proposed tokamak burning plasma experiments such as ITER is described. The ST strategy focuses on a compact Component Test Facility (CTF) and higher performance advanced regimes leading to more attractive DEMO and Power Plant scale reactors. To provide the physics basis for the CTF an intermediate step needs to be taken which we refer to as the ''Next Step Spherical Torus'' (NSST) device and examine in some detail herein. NSST is a ''performance extension'' (PE) stage ST with the plasma current of 5-10 MA, R = 1.5 m, and Beta(sub)T less than or equal to 2.7 T with flexible physics capability. The mission of NSST is to: (1) provide a sufficient physics basis for the design of CTF, (2) explore advanced operating scenarios with high bootstrap current fraction/high performance regimes, which can then be utilized by CTF, DEMO, and Power Plants, and (3) contribute to the general plasma/fusion science of high beta toroidal plasmas. The NSST facility is designed to utilize the Tokamak Fusion Test Reactor (or similar) site to minimize the cost and time required for the design and construction

A TWO-STEP CLASSIFICATION APPROACH TO DISTINGUISHING SIMILAR OBJECTS IN MOBILE LIDAR POINT CLOUDS

Directory of Open Access Journals (Sweden)

H. He

2017-09-01

Full Text Available Nowadays, lidar is widely used in cultural heritage documentation, urban modeling, and driverless car technology for its fast and accurate 3D scanning ability. However, full exploitation of the potential of point cloud data for efficient and automatic object recognition remains elusive. Recently, feature-based methods have become very popular in object recognition on account of their good performance in capturing object details. Compared with global features describing the whole shape of the object, local features recording the fractional details are more discriminative and are applicable for object classes with considerable similarity. In this paper, we propose a two-step classification approach based on point feature histograms and the bag-of-features method for automatic recognition of similar objects in mobile lidar point clouds. Lamp post, street light and traffic sign are grouped as one category in the first-step classification for their inter similarity compared with tree and vehicle. A finer classification of the lamp post, street light and traffic sign based on the result of the first-step classification is implemented in the second step. The proposed two-step classification approach is shown to yield a considerable improvement over the conventional one-step classification approach.

Human factors that derail extension services delivery in developing countries: implications for policy

Directory of Open Access Journals (Sweden)

E.N. Ajani

2012-12-01

Full Text Available The paper examines human factors derailing extension services delivery in developing countries. Poor management of rewards and incentives; quality of work life; poor assessment system; limited quality of human resource; inadequate extension support training materials; inconsistencies of government programmes; inadequate staff training and poor extension programme evaluation were viewed as major constraints. Considering the role of extension to agricultural development, the paper recommends that efforts should be made by the various stakeholders in agricultural extension services to improve the capability of human resources involved in extension services and highlights the need for government agricultural programmes to be consistent to enable the beneficiaries of such programmes derive the benefits that will boost productivity in agriculture.

Extension Stakeholder Engagement: An Exploration of Two Cases Exemplifying 21st Century Adaptions

Directory of Open Access Journals (Sweden)

Charles French

2015-06-01

Full Text Available Over the past 100 years, a number of societal trends have influenced how Cooperative Extension engages public audiences in its outreach and education efforts. These trends include rapid evolution in communication technology, greater specialization of Land-Grant University faculty, and diversification of funding sources. In response, Extension organizations have adapted their engagement approach, incorporated new technologies, modified their organizational structures, and even expanded the notion of public stakeholders to include funders, program nonparticipants, and others. This article explores the implications for future Extension efforts using two case studies—one which explores how a community visioning program incorporated new ways of engaging local audiences, and another which explores how an Extension business retention program used participatory action research and educational organizing approaches to strengthen participation in a research-based program.

“One Step and Two Steps” freezing methods of dog’s semen in coconut water and ethylene glycol extender Métodos de congelamento "One Step" e "Two Steps" do sêmen de cães, diluído em solução de água de coco e etilenoglicol

Directory of Open Access Journals (Sweden)

Marco Antonio da Rocha Ferreira

2009-06-01

Full Text Available The objective of this study was to verify the influence of One Step and Two Steps freezing methods on dog’s spermatic viability. The experiment was performed using 20 ejaculates from 11 previously selected dogs which presented progressive motility over 70% and vigor equal or superior to 3. The samples were frozen in medium composed by coconut water and ethylene glycol as crioprotectant by the methods, One and Two Steps. After thawing, progressive motility, vigor, live spermatozoa percentage and plasmatic membrane integrity were evaluated. The results showed that there was no difference (P>0.05 in evaluated seminal characteristics. For progressive motility, the results (mean ± standard deviation were respectively for One and Two Steps, 47.3% ± 16.6% and 50.5% ±1 7.4%. As well as, the results for vigor, live spermatozoa percentage, plasmatic membrane integrity were 2.64 ± 0.67 and 2.9 ± 0.74; 52.2% ± 24.16 and 52.2% ± 24.48%; 15.27% ± 10.19% and 23.3% ± 11.6% for One and Two Steps methods, respectively. In conclusion, the One Step and Two Steps techniques can be used as semen cryopreservation methods in dog’s assisted reproduction and there is no difference between the evaluated characteristics of frozen-thawed semen using one or other technique.Objetivou-se, com este estudo, verificar a influência dos métodos de congelamento, One Step e Two Steps, na viabilidade espermática em cães. Foram utilizados 20 ejaculados de 11 cães, previamente selecionados, que apresentaram motilidade progressiva acima de 70% e vigor igual ou superior a três. As amostras foram congeladas em meio composto de água de coco e etilenoglicol, pelos métodos de One e Two Steps, e avaliadas após descongelamento, quanto à motilidade progressiva, vigor, porcentagem de espermatozóides vivos e integridade de membrana plasmática. Após o processo de diluição e congelamento One Step e Two Steps, verificou-se que não houve diferença (P>0,05 nas caracter

Chondroitin sulfate synthase-2 is necessary for chain extension of chondroitin sulfate but not critical for skeletal development.

Science.gov (United States)

Ogawa, Hiroyasu; Hatano, Sonoko; Sugiura, Nobuo; Nagai, Naoko; Sato, Takashi; Shimizu, Katsuji; Kimata, Koji; Narimatsu, Hisashi; Watanabe, Hideto

2012-01-01

Chondroitin sulfate (CS) is a linear polysaccharide consisting of repeating disaccharide units of N-acetyl-D-galactosamine and D-glucuronic acid residues, modified with sulfated residues at various positions. Based on its structural diversity in chain length and sulfation patterns, CS provides specific biological functions in cell adhesion, morphogenesis, neural network formation, and cell division. To date, six glycosyltransferases are known to be involved in the biosynthesis of chondroitin saccharide chains, and a hetero-oligomer complex of chondroitin sulfate synthase-1 (CSS1)/chondroitin synthase-1 and chondroitin sulfate synthase-2 (CSS2)/chondroitin polymerizing factor is known to have the strongest polymerizing activity. Here, we generated and analyzed CSS2(-/-) mice. Although they were viable and fertile, exhibiting no overt morphological abnormalities or osteoarthritis, their cartilage contained CS chains with a shorter length and at a similar number to wild type. Further analysis using CSS2(-/-) chondrocyte culture systems, together with siRNA of CSS1, revealed the presence of two CS chain species in length, suggesting two steps of CS chain polymerization; i.e., elongation from the linkage region up to Mr ∼10,000, and further extension. There, CSS2 mainly participated in the extension, whereas CSS1 participated in both the extension and the initiation. Our study demonstrates the distinct function of CSS1 and CSS2, providing a clue in the elucidation of the mechanism of CS biosynthesis.

Step-Up: Promoting Youth Mental Health and Development in Inner-City High Schools.

Science.gov (United States)

Alicea, Stacey; Pardo, Gisselle; Conover, Kelly; Gopalan, Geetha; McKay, Mary

2012-06-01

African American and Latino youth who reside in inner-city communities are at heightened risk for compromised mental health, as their neighborhoods are too often associated with serious stressors, including elevated rates of poverty, substance abuse, community violence, as well as scarce youth-supportive resources, and mental health care options. Many aspects of disadvantaged urban contexts have the potential to thwart successful youth development. Adolescents with elevated mental health needs may experience impaired judgment, poor problem-solving skills, and conflictual interpersonal relationships, resulting in unsafe sexual behavior and drug use. However, mental health services are frequently avoided by urban adolescents who could gain substantial benefit from care. Thus, the development of culturally sensitive, contextually relevant and effective services for urban, low-income African American and Latino adolescents is critical. Given the complexity of the mental health and social needs of urban youth, novel approaches to service delivery may need to consider individual (i.e., motivation to succeed in the future), family (i.e., adult support within and outside of the family), and community-level (i.e., work and school opportunities) clinical components. Step-Up, a high school-based mental health service delivery model has been developed to bolster key family, youth and school processes related to youth mental health and positive youth development. Step-Up (1) intervenes with urban minority adolescents across inner-city ecological domains; (2) addresses multiple levels (school, family and community) in order to target youth mental health difficulties; and (3) provides opportunities for increasing youth social problem-solving and life skills. Further, Step-Up integrates existing theory-driven, evidence-based interventions. This article describes Step-Up clinical goals, theoretical influences, as well as components and key features, and presents preliminary data on

Two steps to suicide in crickets harbouring hairworms

DEFF Research Database (Denmark)

Sanchez, M.I.; Ponton, F.; Schmidt-Rhaesa, A.

2008-01-01

predicted that hairworms should adaptively manipulate host behaviour to maximize parasite reproductive success. Our results supported the hypothesis that the host manipulation strategy of hairworms consists of at least two distinct steps, first the induction of erratic behaviour and then suicidal behaviour...... per se. Hairworms secured mating by starting to manipulate their host before being fully mature. Once induced, the cricket's suicidal behaviour was maintained until the host found water but the fecundity of worms decreased over time. As expected, the fecundity of worms was better in crickets...... with suicidal rather than erratic behaviour. (C) 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved...

Numerical calculation on a two-step subdiffusion behavior of lateral protein movement in plasma membranes

Science.gov (United States)

Sumi, Tomonari; Okumoto, Atsushi; Goto, Hitoshi; Sekino, Hideo

2017-10-01

A two-step subdiffusion behavior of lateral movement of transmembrane proteins in plasma membranes has been observed by using single-molecule experiments. A nested double-compartment model where large compartments are divided into several smaller ones has been proposed in order to explain this observation. These compartments are considered to be delimited by membrane-skeleton "fences" and membrane-protein "pickets" bound to the fences. We perform numerical simulations of a master equation using a simple two-dimensional lattice model to investigate the heterogeneous diffusion dynamics behavior of transmembrane proteins within plasma membranes. We show that the experimentally observed two-step subdiffusion process can be described using fence and picket models combined with decreased local diffusivity of transmembrane proteins in the vicinity of the pickets. This allows us to explain the two-step subdiffusion behavior without explicitly introducing nested double compartments.

Two-step calibration method for multi-algorithm score-based face recognition systems by minimizing discrimination loss

NARCIS (Netherlands)

Susyanto, N.; Veldhuis, R.N.J.; Spreeuwers, L.J.; Klaassen, C.A.J.; Fierrez, J.; Li, S.Z.; Ross, A.; Veldhuis, R.; Alonso-Fernandez, F.; Bigun, J.

2016-01-01

We propose a new method for combining multi-algorithm score-based face recognition systems, which we call the two-step calibration method. Typically, algorithms for face recognition systems produce dependent scores. The two-step method is based on parametric copulas to handle this dependence. Its

Two-step optimization of pressure and recovery of reverse osmosis desalination process.

Science.gov (United States)

Liang, Shuang; Liu, Cui; Song, Lianfa

2009-05-01

Driving pressure and recovery are two primary design variables of a reverse osmosis process that largely determine the total cost of seawater and brackish water desalination. A two-step optimization procedure was developed in this paper to determine the values of driving pressure and recovery that minimize the total cost of RO desalination. It was demonstrated that the optimal net driving pressure is solely determined by the electricity price and the membrane price index, which is a lumped parameter to collectively reflect membrane price, resistance, and service time. On the other hand, the optimal recovery is determined by the electricity price, initial osmotic pressure, and costs for pretreatment of raw water and handling of retentate. Concise equations were derived for the optimal net driving pressure and recovery. The dependences of the optimal net driving pressure and recovery on the electricity price, membrane price, and costs for raw water pretreatment and retentate handling were discussed.

ADDING A NEW STEP WITH SPATIAL AUTOCORRELATION TO IMPROVE THE FOUR-STEP TRAVEL DEMAND MODEL WITH FEEDBACK FOR A DEVELOPING CITY

Directory of Open Access Journals (Sweden)

Xuesong FENG, Ph.D Candidate

2009-01-01

Full Text Available It is expected that improvement of transport networks could give rise to the change of spatial distributions of population-related factors and car ownership, which are expected to further influence travel demand. To properly reflect such an interdependence mechanism, an aggregate multinomial logit (A-MNL model was firstly applied to represent the spatial distributions of these exogenous variables of the travel demand model by reflecting the influence of transport networks. Next, the spatial autocorrelation analysis is introduced into the log-transformed A-MNL model (called SPA-MNL model. Thereafter, the SPA-MNL model is integrated into the four-step travel demand model with feedback (called 4-STEP model. As a result, an integrated travel demand model is newly developed and named as the SPA-STEP model. Using person trip data collected in Beijing, the performance of the SPA-STEP model is empirically compared with the 4-STEP model. It was proven that the SPA-STEP model is superior to the 4-STEP model in accuracy; most of the estimated parameters showed statistical differences in values. Moreover, though the results of the simulations to the same set of assumed scenarios by the 4-STEP model and the SPA-STEP model consistently suggested the same sustainable path for the future development of Beijing, it was found that the environmental sustainability and the traffic congestion for these scenarios were generally overestimated by the 4-STEP model compared with the corresponding analyses by the SPA-STEP model. Such differences were clearly generated by the introduction of the new modeling step with spatial autocorrelation.

Preparation for the Nuclear Non-Proliferation Treaty Extension Conference in 1995

International Nuclear Information System (INIS)

Chrzanowski, P.L.

1993-01-01

About 30 specialists in non-proliferation participated in a workshop to explore ideas for US Government preparatory steps leading to the 1995 Nuclear Non-Proliferation Treaty (NPT) Extension Conference. To that end, workshop sessions were devoted to reviewing the lessons learned from previous Review Conferences, discussing the threats to the non-proliferation regime together with ways of preserving and strengthening it, and examining the management of international nuclear commerce. A fundamental premise shared by workshop participants was that extension of the NPT is immensely important to international security. The importance of stemming proliferation and, more specifically, extending the Treaty, is growing as a result of the significant changes in the world. If the conferees of the Extension Conference decide on no extension or extension for a short limited duration, some technically advanced states that have foregone development of nuclear weapons may begin to rethink their options. Also, other arms control measures, such as the Chemical Weapons Convention, could start to unravel. The US must provide strong international leadership to ensure that the Extension Conference is a success, resulting in Treaty extension, perhaps through successive terms, into the indefinite future. Workshop participants were struck by the urgent need for the US to take organizational steps so that it is highly effective in its advance preparations for the Extension Conference. Moreover, the Extension Conference provides both a challenge and an opportunity to mold a cohesive set of US policy actions to define the future role of nuclear weapons and combat their proliferation

Tranfusion risk: is "two-step" vaginal delivery a risk for postpartum hemorrhage?

Science.gov (United States)

Straface, Gianluca; Bassi, Emma; De Santis, Marco; Scambia, Giovanni; Zanardo, Vincenzo

2015-01-01

In the active management strategy of third stage of labor, the optimal timing for clamping the umbilical cord after birth has been a subject of controversy. We want to evaluate if "two-step" delivery is a risk factor for postpartum hemorrhage (PPH), defined as need of transfusion, comparing to operative delivery, elective caesarean delivery and emergency caesarean delivery. This is a retrospective cohort study conducted in division of Perinatal Medicine, Policlinico Abano Terme. We evaluated the need of transfusion in all cases of PPH verified in all single deliveries between January 2011 and December 2012. The main outcome measure was blood loss and red blood cell transfusion. We found 17 cases of PPH (0.88%). The distribution of PPH in relation to mode of delivery was 0.71%, 2.46% and 1.98% respectively for two-step vaginal delivery (RR = 0.81 (0.56-1.22)), emergency cesarean section (RR = 2.88 (1.27-7.77)) and operative vaginal delivery (RR = 2.88 (0.59-5.66)). In labor induction there is a stronger relative risk association between PPH and as emergency cesarean delivery (p < 0.05) as operative vaginal delivery (p < 0.05). "Two-step" delivery approach did not increase the risk of PPH with respect to operative delivery, elective caesarean section and emergency caesarean section.

Electrohydraulic linear actuator with two stepping motors controlled by overshoot-free algorithm

Science.gov (United States)

Milecki, Andrzej; Ortmann, Jarosław

2017-11-01

The paper describes electrohydraulic spool valves with stepping motors used as electromechanical transducers. A new concept of a proportional valve in which two stepping motors are working differentially is introduced. Such valve changes the fluid flow proportionally to the sum or difference of the motors' steps numbers. The valve design and principle of its operation is described. Theoretical equations and simulation models are proposed for all elements of the drive, i.e., the stepping motor units, hydraulic valve and cylinder. The main features of the valve and drive operation are described; some specific problem areas covering the nature of stepping motors and their differential work in the valve are also considered. The whole servo drive non-linear model is proposed and used further for simulation investigations. The initial simulation investigations of the drive with a new valve have shown that there is a significant overshoot in the drive step response, which is not allowed in positioning process. Therefore additional effort is spent to reduce the overshoot and in consequence reduce the settling time. A special predictive algorithm is proposed to this end. Then the proposed control method is tested and further improved in simulations. Further on, the model is implemented in reality and the whole servo drive system is tested. The investigation results presented in this paper, are showing an overshoot-free positioning process which enables high positioning accuracy.

Two-stage bargaining with coverage extension in a dual labour market

DEFF Research Database (Denmark)

Roberts, Mark A.; Stæhr, Karsten; Tranæs, Torben

2000-01-01

This paper studies coverage extension in a simple general equilibrium model with a dual labour market. The union sector is characterized by two-stage bargaining whereas the firms set wages in the non-union sector. In this model firms and unions of the union sector have a commonality of interest...

Structural comparison of anodic nanoporous-titania fabricated from single-step and three-step of anodization using two paralleled-electrodes anodizing cell

Directory of Open Access Journals (Sweden)

Mallika Thabuot

2016-02-01

Full Text Available Anodization of Ti sheet in the ethylene glycol electrolyte containing 0.38wt% NH4F with the addition of 1.79wt% H2O at room temperature was studied. Applied potential of 10-60 V and anodizing time of 1-3 h were conducted by single-step and three-step of anodization within the two paralleled-electrodes anodizing cell. Their structural and textural properties were investigated by X-ray diffraction (XRD and scanning electron microscopy (SEM. After annealing at 600°C in the air furnace for 3 h, TiO2-nanotubes was transformed to the higher proportion of anatase crystal phase. Also crystallization of anatase phase was enhanced as the duration of anodization as the final step increased. By using single-step of anodization, pore texture of oxide film was started to reveal at the applied potential of 30 V. Better orderly arrangement of the TiO2-nanotubes array with larger pore size was obtained with the increase of applied potential. The applied potential of 60 V was selected for the three-step of anodization with anodizing time of 1-3 h. Results showed that the well-smooth surface coverage with higher density of porous-TiO2 was achieved using prolonging time at the first and second step, however, discontinuity tube in length was produced instead of the long-vertical tube. Layer thickness of anodic oxide film depended on the anodizing time at the last step of anodization. More well arrangement of nanostructured-TiO2 was produced using three-step of anodization under 60 V with 3 h for each step.

Estimating reaction rate constants from a two-step reaction: a comparison between two-way and three-way methods

NARCIS (Netherlands)

Bijlsma, S.; Smilde, A. K.

2000-01-01

In this paper, two different spectral datasets are used in order to estimate reaction rate constants using different algorithms. Dataset 1 consists of short-wavelength near-infrared (SW NIR) spectra taken in time of the two-step epoxidation of 2,5-di-tert-butyl-1,4-benzoquinone using tert-butyl

Development of Stepped-Frequency Ground-Penetrating Radar

DEFF Research Database (Denmark)

Jakobsen, Kaj Bjarne

1998-01-01

The status of the development of a multi-monostatic stepped-frequency ground-penetrating radar (GPR) at The Department of Applied Electronics (IAE), The Technical University of Denmark (DTU) is presented. The feasibility of the used approach is demonstrated by the successful detection of small me...... metallic and non-metallic objects with a diameter of 54 mm buried in loamy soil....

Preparation of biodiesel from waste cooking oil via two-step catalyzed process

International Nuclear Information System (INIS)

Wang Yong; Liu Pengzhan; Ou Shiyi; Zhang Zhisen

2007-01-01

Waste cooking oils (WCO), which contain large amounts of free fatty acids produced in restaurants, are collected by the environmental protection agency in the main cities of China and should be disposed in a suitable way. In this research, a two step catalyzed process was adopted to prepare biodiesel from waste cooking oil whose acid value was 75.92 ± 0.036 mgKOH/g. The free fatty acids of WCO were esterified with methanol catalyzed by ferric sulfate in the first step, and the triglycerides (TGs) in WCO were transesterified with methanol catalyzed by potassium hydroxide in the second step. The results showed that ferric sulfate had high activity to catalyze the esterification of free fatty acids (FFA) with methanol, The conversion rate of FFA reached 97.22% when 2 wt% of ferric sulfate was added to the reaction system containing methanol to TG in10:1 (mole ratio) composition and reacted at 95 deg. C for 4 h. The methanol was vacuum evaporated, and transesterification of the remained triglycerides was performed at 65 deg. C for 1 h in a reaction system containing 1 wt% of potassium hydroxide and 6:1 mole ratio of methanol to TG. The final product with 97.02% of biodiesel, obtained after the two step catalyzed process, was analyzed by gas chromatography. This new process has many advantages compared with the old processes, such as no acidic waste water, high efficiency, low equipment cost and easy recovery of the catalyst

Effectiveness of a two-step population-based osteoporosis screening program using FRAX

DEFF Research Database (Denmark)

Rubin, K H; Rothmann, M J; Holmberg, T

2018-01-01

The Risk-stratified Osteoporosis Strategy Evaluation (ROSE) study investigated the effectiveness of a two-step screening program for osteoporosis in women. We found no overall reduction in fractures from systematic screening compared to the current case-finding strategy. The group of moderate......- to high-risk women, who accepted the invitation to DXA, seemed to benefit from the program. INTRODUCTION: The purpose of the ROSE study was to investigate the effectiveness of a two-step population-based osteoporosis screening program using the Fracture Risk Assessment Tool (FRAX) derived from a self......-administered questionnaire to select women for DXA scan. After the scanning, standard osteoporosis management according to Danish national guidelines was followed. METHODS: Participants were randomized to either screening or control group, and randomization was stratified according to age and area of residence. Inclusion...

Design of a Two-Step Calibration Method of Kinematic Parameters for Serial Robots

Science.gov (United States)

WANG, Wei; WANG, Lei; YUN, Chao

2017-03-01

Serial robots are used to handle workpieces with large dimensions, and calibrating kinematic parameters is one of the most efficient ways to upgrade their accuracy. Many models are set up to investigate how many kinematic parameters can be identified to meet the minimal principle, but the base frame and the kinematic parameter are indistinctly calibrated in a one-step way. A two-step method of calibrating kinematic parameters is proposed to improve the accuracy of the robot's base frame and kinematic parameters. The forward kinematics described with respect to the measuring coordinate frame are established based on the product-of-exponential (POE) formula. In the first step the robot's base coordinate frame is calibrated by the unit quaternion form. The errors of both the robot's reference configuration and the base coordinate frame's pose are equivalently transformed to the zero-position errors of the robot's joints. The simplified model of the robot's positioning error is established in second-power explicit expressions. Then the identification model is finished by the least square method, requiring measuring position coordinates only. The complete subtasks of calibrating the robot's 39 kinematic parameters are finished in the second step. It's proved by a group of calibration experiments that by the proposed two-step calibration method the average absolute accuracy of industrial robots is updated to 0.23 mm. This paper presents that the robot's base frame should be calibrated before its kinematic parameters in order to upgrade its absolute positioning accuracy.

Getting started with OpenCart module development

CERN Document Server

Nepali, Rupak

2013-01-01

Written as a step-by-step guide, Getting Started with OpenCart Module Development will teach you all you need to know about OpenCart, from custom extensions to module development.This book is for developers who want to develop OpenCart extensions and for those who want to learn more about the code workflow of OpenCart. Basic knowledge of OpenCart would be an added advantage.

Normal Range of Head-to-body Delivery Interval by Two-step Delivery

Directory of Open Access Journals (Sweden)

Hong-Yu Zhang

2016-01-01

Conclusions: The average time of head-to-body delivery interval was longer than 60 s by two-step delivery. Majority shoulders were delivered at the first contraction. Majority shoulders emerged from perineum rather from under pubic arch. The routine one-step method of shoulder delivery where the downward force applied is not necessary and is not the right direction. Baby's breath, making faces, sucking, bubble from noses and mouth, and the light blue color of the faces, all those signs during shoulder delivery indicated a normal live birth.

Preparation and photocatalytic degradation performance of Ag_3PO_4 with a two-step approach

International Nuclear Information System (INIS)

Li, Jiwen; Ji, Xiaojing; Li, Xian; Hu, Xianghua; Sun, Yanfang; Ma, Jingjun; Qiao, Gaowei

2016-01-01

Highlights: • Ag_3PO_4 photocatalysts were synthesized via one-step and two-step ion-exchange reaction. • Photocatalytic properties of Ag_3PO_4 photocatalysts was investigated, the result indicated the Ag_3PO_4 (2) was higher than that of Ag_3PO_4 (1) under the same experimental condition. • Ag_3PO_4 (2) particles were larger than Ag_3PO_4 (1) particles and many polygonal-shaped surfaces could be clearly observed in the Ag_3PO_4 (2) particles. - Abstract: Ag_3PO_4 photocatalysts were prepared via two and one-step through a facile ion-exchange route. The photocatalysts were then characterized through powder X-ray diffraction, scanning electron microscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of the samples was evaluated on the basis of the photocatalytic degradation of methyl orange (MO) and methylene blue (MB) under solar irradiation. The MO degradation rate of the Photocatalyst synthesized by the two-step ion-exchange route was 89.18% in 60 min. This value was four times that of the Photocatalyst synthesized by the one-step approach.The MB degradation rate was 97% in 40 min. After six cycling runs were completed, the MO degradation rate was 73%

Decentralised treatment of concentrated sewage at low temperature in a two-step anaerobic system: two upflow-hybrid septic tanks

NARCIS (Netherlands)

Elmitwally, T.A.; Sayed, S.; Groendijk, L.; Lier, van J.B.; Zeeman, G.; Lettinga, G.

2003-01-01

The decentralised treatment of concentrated sewage (about 3,600 mgCOD/1) at low temperature was investigated in a two-step anaerobic system: two-anaerobic hybrid (AH) septic tanks (each 0.575 m(3)). The two reactors were placed in a temperature controlled-room and the HRT was 2.5 days for each

Development of procedural requirements for life extension of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Hoon; Son, Moon Kyu [Korea Association for Nuclear Technology, Taejon (Korea, Republic of); Jeong, Ji Hwan [Baekseok College, Cheonan (Korea, Republic of); Chang, Keun Sun [Sunmoon Univ., Asan (Korea, Republic of); Ham, Chul Hoon [The Catholic University of Korea, Seoul (Korea, Republic of); Chang, Soon Hong [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

2002-03-15

Technical issues relevant to life extension of NPP were investigated. The GALL report, domestic PSR and periodic inspection rules were reviewed. Technical issues appearing in the safety evaluation reports related to license renewal of Calvert Ciffs 1 and 2 and Qconee 1,2 and 3 NPPs were reviewed. Preliminary study on PSA usage in NPP life extension assessment was performed and further works were suggested. The environment of rules and regulations was analyzed from the viewpoint of plant life extension. Two alternatives are suggested to revise the current domestic nuclear acts.

Development of procedural requirements for life extension of nuclear power plants

International Nuclear Information System (INIS)

Lee, Sang Hoon; Son, Moon Kyu; Jeong, Ji Hwan; Chang, Keun Sun; Ham, Chul Hoon; Chang, Soon Hong

2002-03-01

Technical issues relevant to life extension of NPP were investigated. The GALL report, domestic PSR and periodic inspection rules were reviewed. Technical issues appearing in the safety evaluation reports related to license renewal of Calvert Ciffs 1 and 2 and Qconee 1,2 and 3 NPPs were reviewed. Preliminary study on PSA usage in NPP life extension assessment was performed and further works were suggested. The environment of rules and regulations was analyzed from the viewpoint of plant life extension. Two alternatives are suggested to revise the current domestic nuclear acts

Using C Language Extensions for Developing Embedded Software : A Case Study

NARCIS (Netherlands)

Voelter, M.; Van Deursen, A.; Kolb, B.; Eberle, S.

2015-01-01

We report on an industrial case study on developing the embedded software for a smart meter using the C programming language and domain-specific extensions of C such as components, physical units, state machines, registers and interrupts. We find that the extensions help significantly with managing

Purdue Extension: Employee Engagement and Leadership Style

Science.gov (United States)

Abbott, Angela R.

2017-01-01

The purpose of this quantitative study was to assess the Purdue Extension county directors' level of engagement and leadership style and to examine the relationship between these two variables. The study aimed to inform a professional development training program for all Purdue Extension county extension directors. Survey data were collected from…

Approaches of Extension Specialists to Teaching Community and Economic Development.

Science.gov (United States)

Leones, Julie

1995-01-01

Responses from 64 of 80 extension agents specializing in community resources and economic development identified the "Journal of the Community Development Society" as the primary source of ideas and information. Frequently cited program topics were entrepreneurship, fiscal policy, budgeting, strategic planning, and leadership development. Among…

Liquid-phase reforming and hydrodeoxygenation as a two-step route to aromatics from lignin

NARCIS (Netherlands)

Jongerius, A.L.; Bruijnincx, P.C.A.; Weckhuysen, B.M.

2013-01-01

A two-step approach to the conversion of organosolv, kraft and sugarcane bagasse lignin to monoaromatic compounds of low oxygen content is presented. The first step consists of lignin depolymerization in a liquid phase reforming (LPR) reaction over a 1 wt% Pt/γ-Al2O3 catalyst at 225 °C in alkaline

Forward-backward rapidity correlations in a two-step scenario

International Nuclear Information System (INIS)

Brogueira, P.; Dias de Deus, J.

2007-01-01

We argue that two-step models, like String and Glasma models, with creation first of sources extended in rapidity that after locally decay into particles, lead to long range forward-backward correlations due to fluctuations in the number or the colour of the sources, and to a similar expression for the F-B correlation parameter b. In the simplest String percolation scenario, b increases with centrality or the number of participating nucleons. However, asymptotically it decreases with energy. This is different from the Glasma model where b increases with both, centrality and energy

Two-step purification of His-tagged Nef protein in native condition using heparin and immobilized metal ion affinity chromatographies.

Science.gov (United States)

Finzi, Andrés; Cloutier, Jonathan; Cohen, Eric A

2003-07-01

The Nef protein encoded by human immunodeficiency virus type 1 (HIV-1) has been shown to be an important factor of progression of viral growth and pathogenesis in both in vitro and in vivo. The lack of a simple procedure to purify Nef in its native conformation has limited molecular studies on Nef function. A two-step procedure that includes heparin and immobilized metal ion affinity chromatographies (IMACs) was developed to purify His-tagged Nef (His(6)-Nef) expressed in bacteria in native condition. During the elaboration of this purification procedure, we identified two closely SDS-PAGE-migrating contaminating bacterial proteins, SlyD and GCHI, that co-eluted with His(6)-Nef in IMAC in denaturing condition and developed purification steps to eliminate these contaminants in native condition. Overall, this study describes a protocol that allows rapid purification of His(6)-Nef protein expressed in bacteria in native condition and that removes metal affinity resin-binding bacterial proteins that can contaminate recombinant His-tagged protein preparation.

Development of the step complexity measure for emergency operating procedures using entropy concepts

International Nuclear Information System (INIS)

Park, Jinkyun; Jung, Wondea; Ha, Jaejoo

2001-01-01

For a nuclear power plant (NPP), symptom-based emergency operating procedures (EOPs) have been adopted to enhance the safety of NPPs through reduction of operators' workload under emergency conditions. Symptom-based EOPs, however, could place a workload on operators because they have to not only identify related symptoms, but also understand the context of steps that should be carried out. Therefore, many qualitative checklists are suggested to ensure the appropriateness of steps included in EOPs. However, since these qualitative evaluations have some drawbacks, a quantitative measure that can roughly estimate the complexity of EOP steps is imperative to compensate for them. In this paper, a method to evaluate the complexity of an EOP step is developed based on entropy measures that have been used in software engineering. Based on these, step complexity (SC) measure that can evaluate SC from various viewpoints (such as the amount of information/operators' actions included in each EOP step, and the logic structure of each EOP step) was developed. To verify the suitableness of the SC measure, estimated SC values are compared with subjective task load scores obtained from the NASA-TLX (task load index) method and step performance time obtained from a full scope simulator. From these comparisons, it was observed that estimated SC values generally agree with the NASA-TLX scores and step performance time data. Thus, it could be concluded that the developed SC measure would be considered for evaluating SC of an EOP step

Study of the highly ordered TiO2 nanotubes physical properties prepared with two-step anodization

Science.gov (United States)

Pishkar, Negin; Ghoranneviss, Mahmood; Ghorannevis, Zohreh; Akbari, Hossein

2018-06-01

Highly ordered hexagonal closely packed titanium dioxide nanotubes (TiO2 NTs) were successfully grown by a two-step anodization process. The TiO2 NTs were synthesized by electrochemical anodization of titanium foils in an ethylene glycol based electrolyte solution containing 0.3 wt% NH4F and 2 vol% deionized (DI) water at constant potential (50 V) for 1 h at room temperature. Physical properties of the TiO2 NTs, which were prepared via one and two-step anodization, were investigated. Atomic Force Microscopy (AFM) analysis revealed that anodization and subsequently peeled off the TiO2 NTs caused to the periodic pattern on the Ti surface. In order To study the nanotubes morphology, Field Emission Scanning Electron Microscopy (FESEM) was used, which was revealed that the two-step anodization resulted highly ordered hexagonal TiO2 NTs. Crystal structures of the TiO2 NTs were mainly anatase, determined by X-ray diffraction analysis. Optical studies were performed by Diffuse Reflection Spectra (DRS) and Photoluminescence (PL) analysis showed that the band gap of TiO2 NTs prepared via two-step anodization was lower than the band gap of samples prepared by one-step anodization process.

Dimension and extensions

CERN Document Server

Aarts, JM

1993-01-01

Two types of seemingly unrelated extension problems are discussed in this book. Their common focus is a long-standing problem of Johannes de Groot, the main conjecture of which was recently resolved. As is true of many important conjectures, a wide range of mathematical investigations had developed, which have been grouped into the two extension problems. The first concerns the extending of spaces, the second concerns extending the theory of dimension by replacing the empty space with other spaces. The problem of de Groot concerned compactifications of spaces by means of an adjunction of a set of minimal dimension. This minimal dimension was called the compactness deficiency of a space. Early success in 1942 lead de Groot to invent a generalization of the dimension function, called the compactness degree of a space, with the hope that this function would internally characterize the compactness deficiency which is a topological invariant of a space that is externally defined by means of compact extensions of a...

High efficiency two-step evaporator in a cooling system; Hocheffiziente zweistufige Verdampfung in einer Kaelteanlage - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Meister, R.; Haenni, E. [BMS-Energieanlagen AG, Wilderswil (Switzerland)

2005-07-01

A two-step evaporator was installed in parallel in an existing refrigeration plant with an operating capacity Q{sub o} of 130 kW. This ensured the possibility of a practical comparison between conventional evaporation and our high-efficiency two-step evaporator, without having to resort only to theoretical data. The result of this virtually one-on-one comparison in identical ambient conditions (which is not normally possible, as two systems cannot generally be installed in parallel) has confirmed what the advance calculations demonstrated, i.e. a 10% improvement in performance provided by the high-efficiency two-step evaporator. Thanks to the changeover from semi-floated to overflow operation (only tested in winter) it was possible, again as shown in previous calculations, to achieve an additional increase in performance of 5%. A basic objective was to use the high-efficiency two-step evaporator to provide stable performance in any operating situation - i.e. even after defrosting. This objective was achieved in both operating modes: semi-floated and overflow. Summer operation in overflow mode remains to be tested however, as the system has only been running in this mode since November 2004. (author)

Novel two-step method to form silk fibroin fibrous hydrogel

International Nuclear Information System (INIS)

Ming, Jinfa; Li, Mengmeng; Han, Yuhui; Chen, Ying; Li, Han; Zuo, Baoqi; Pan, Fukui

2016-01-01

Hydrogels prepared by silk fibroin solution have been studied. However, mimicking the nanofibrous structures of extracellular matrix for fabricating biomaterials remains a challenge. Here, a novel two-step method was applied to prepare fibrous hydrogels using regenerated silk fibroin solution containing nanofibrils in a range of tens to hundreds of nanometers. When the gelation process of silk solution occurred, it showed a top-down type gel within 30 min. After gelation, silk fibroin fibrous hydrogels exhibited nanofiber network morphology with β-sheet structure. Moreover, the compressive stress and modulus of fibrous hydrogels were 31.9 ± 2.6 and 2.8 ± 0.8 kPa, respectively, which was formed using 2.0 wt.% concentration solutions. In addition, fibrous hydrogels supported BMSCs attachment and proliferation over 12 days. This study provides important insight in the in vitro processing of silk fibroin into useful new materials. - Highlights: • SF fibrous hydrogel was prepared by a novel two-step method. • SF solution containing nanofibrils in a range of tens to hundreds of nanometers was prepared. • Gelation process was top-down type gel with several minutes. • SF fibrous hydrogels exhibited nanofiber network morphology with β-sheet structure. • Fibrous hydrogels had higher compressive stresses superior to porous hydrogels.

78 FR 54756 - Extension of Expiration Dates for Two Body System Listings

Science.gov (United States)

2013-09-06

... Security Online, at http://www.socialsecurity.gov . SUPPLEMENTARY INFORMATION: Background We use the... SOCIAL SECURITY ADMINISTRATION 20 CFR Part 404 [Docket No. SSA-2013-0039] RIN 0960-AH60 Extension of Expiration Dates for Two Body System Listings AGENCY: Social Security Administration. ACTION...

Two-step superconducting transition in Cu-V-Si alloys

International Nuclear Information System (INIS)

Sharma, R.G.; Krishna, M.M.; Narlikar, A.V.

1980-01-01

Copper ternary alloys containing small amounts of vanadium and silicon exhibit a two-step superconducting resistive transition. The first transition occurs around 17 K, the transition temperature of β-W V 3 Si, followed by a plateau and a second transition around 10 K. The resistivity, however, does not drop to zero down to 2.5 K. Reduction of the wire diameter causes the two transitions to shift to lower temperatures. Complete superconductivity in these specimens is absent for two reasons. Firstly, the superconducting volume fraction present in these alloy-wires is below the threshold given by either the effective-medium theory or the site percolation theory. Secondly, the superconducting phase V 3 Si does not precipitate in copper matrix in a fine structure and the proximity effect does not operate strongly. Annealing causes the superconducting particles to coalesce and grow in size and suppresses the proximity effect and superconductivity further in these alloy wires. (author)

On Parseval Wavelet Frames with Two or Three Generators via the Unitary Extension Principle

DEFF Research Database (Denmark)

Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

2014-01-01

The unitary extension principle (UEP) by A. Ron and Z. Shen yields a sufficient condition for the construction of Parseval wavelet frames with multiple generators. In this paper we characterize the UEP-type wavelet systems that can be extended to a Parseval wavelet frame by adding just one UEP......-type wavelet system. We derive a condition that is necessary for the extension of a UEP-type wavelet system to any Parseval wavelet frame with any number of generators and prove that this condition is also sufficient to ensure that an extension with just two generators is possible....

77 FR 6517 - Economic Development Administration Regulatory Revision; Comment Period Extension

Science.gov (United States)

2012-02-08

... DEPARTMENT OF COMMERCE Economic Development Administration 13 CFR Parts 300, 301, 302, 303, 304... Development Administration Regulatory Revision; Comment Period Extension AGENCY: Economic Development.... SUMMARY: On December 7, 2011, the Department of Commerce's Economic Development Administration (EDA...

Subharmonic structure of Shapiro steps in frustrated superconducting arrays

International Nuclear Information System (INIS)

Kim, S.; Kim, B.J.; Choi, M.Y.

1995-01-01

Two-dimensional superconducting arrays with combined direct and alternating applied currents are studied both analytically and numerically. In particular, we investigate in detail current-voltage characteristics of a square array with 1/2 flux quantum per plaquette and triangular arrays with 1/2 and 1/4 flux quantum per plaquette. At zero temperature reduced equations of motion are obtained through the use of the translational symmetry present in the systems. The reduced equations lead to a series of subharmonic steps in addition to the standard integer and fractional giant Shapiro steps, producing devil's staircase structure. This devil's staircase structure reflects the existence of dynamically generated states in addition to the states originating from degenerate ground states in equilibrium. Widths of the subharmonic steps as functions of the amplitudes of alternating currents display Bessel-function-type behavior. We also present results of extensive numerical simulations, which indeed reveal the subharmonic steps together with their stability against small thermal fluctuations. Implications for topological invariance are also discussed

Life extension economic analysis

International Nuclear Information System (INIS)

Smithling, A.P.

1992-01-01

Life extension economic analyses of fossil fueled power plants need the development of consistent methods which consider the capital costs associated with component replacement or repair and estimates of normal station capital expenditures over the units remaining life. In order to link capital and production costs, Niagra Mohawk Power Corp. develops most and worst cases. A most case includes capital components that would definitely need replacement or modification for life extension. The worst case scenario contains must case capital costs plus various components which may need replacement or modification. In addition, two forecasted conditions are used, base case capacity and low capacity

Safety of the two-step tuberculin skin test in Indian health care workers.

Science.gov (United States)

Christopher, Devasahayam J; Shankar, Deepa; Datey, Ashima; Zwerling, Alice; Pai, Madhukar

2014-12-01

Health care workers (HCW) in low and middle income countries are at high risk of nosocomial tuberculosis infection. Periodic screening of health workers for both TB disease and infection can play a critical role in TB infection control. Occupational health programs that implement serial tuberculin skin testing (TST) are advised to use a two-step baseline TST. This helps to ensure that boosting of waned immune response is not mistaken as new TB infection (i.e. conversion). However, there are no data on safety of the two-step TST in the Indian context where HCWs are repeatedly exposed. Nursing students were recruited from 2007 to 2009 at the Christian Medical College and Hospital, Vellore, India. Consenting nursing students were screened with a baseline two-step TST at the time of recruitment. From 2007 to 2008 adverse events were recorded when reported during the TST reading (Cohort A). Nurses recruited in the final study year (2009) answered an investigator administered questionnaire assessing all likely side-effects Cohort B). This information was extracted from the case report forms and analysed. Between 2007 and 09, 800 trainees consented to participate in the annual TB screening study and 779 did not have a past history of TB or recall a positive TST and were selected to administer TST. Of these, 755 returned for reading the result and had complete data and were included for the final analysis - 623 subjects in (cohort A) and 132 in (cohort B). These were included for the final analysis. In cohort A only 1.3% reported adverse events. In cohort B, as per the investigator administered questionnaire; 25% reported minor side effects. Itching and local pain were the most common side effects encountered. There were no major adverse events reported. In particular, the adverse events were similar in the second step of the test and not more severe. Screening of HCWs with two-step TST for LTBI is simple and safe, and hence suitable for wide scale implementation in high

A re-examination of two-step lateral stress history in silicon carbide

International Nuclear Information System (INIS)

Dandekar, Dattatraya P.

2004-01-01

The observed two-step lateral stress history in silicon carbide, SiC-B under plane shock wave propagation [N. K. Bourne, J. Millett, and I. Pickup, J. Appl. Phys. 81, 6019 (1997)] is attributed to a delayed failure in SiC-B due to propagation of a slow moving front traveling behind the main shock wave. According to this attribution, the first lower magnitude, step corresponds to the lateral stress in intact shock compressed silicon carbide as a result of the fast moving plane shock wave. The second step of higher magnitude, observed after a few hundred nanoseconds, corresponds to the lateral stress in failed silicon carbide due to propagation of the slower moving front. The current analysis, takes into account additional relevant existing results dealing with shock response of SiC-B, and shows that the suggested explanation for the observed phenomenon remains in doubt

Development and Validation of an Automated Step Ergometer

Directory of Open Access Journals (Sweden)

C. de Sousa Maria do Socorro

2014-12-01

Full Text Available Laboratory ergometers have high costs, becoming inaccessible for most of the population, hence, it is imperative to develop affordable devices making evaluations like cardiorespiratory fitness feasible and easier. The objective of this study was to develop and validate an Automated Step Ergometer (ASE, adjusted according to the height of the subject, for predicting VO2max through a progressive test. The development process was comprised by three steps, the theoretical part, the prototype assembly and further validation. The ASE consists in an elevating platform that makes the step at a higher or lower level as required for testing. The ASE validation was obtained by comparing the values of predicted VO2max (equation and direct gas analysis on the prototype and on a, treadmill. For the validation process 167 subjects with average age of 31.24 ± 14.38 years, of both genders and different degrees of cardiorespiratory fitness, were randomized and divided by gender and training condition, into untrained (n=106, active (n=24 and trained (n=37 subjects. Each participant performed a progressive test on which the ASE started at the same height (20 cm for all. Then, according to the subject’s height, it varied to a maximum of 45 cm. Time in each stage and rhythm was chosen in accordance with training condition from lowest to highest (60-180 s; 116-160 bpm, respectively. Data was compared with the student’s t test and ANOVA; correlations were tested with Pearson’s r. The value of α was set at 0.05. No differences were found between the predicted VO2max and the direct gas analysis VO2max, nor between the ASE and treadmill VO2max (p= 0.365 with high correlation between ergometers (r= 0.974. The values for repeatability, reproducibility, and reliability of male and female groups measures were, respectively, 4.08 and 5.02; 0.50 and 1.11; 4.11 and 5.15. The values of internal consistency (Cronbach’s alpha among measures were all >0.90. It was verified

Metronome-Cued Stepping in Place after Hemiparetic Stroke: Comparison of a One- and Two-Tone Beat

OpenAIRE

Wright, Rachel L.; Masood, Afia; Maccormac, Elinor S.; Pratt, David; Sackley, Catherine M.; Wing, Alan M.

2013-01-01

Hemiparetic gait is characterised by temporal asymmetry and variability, and these variables are improved by auditory cueing. Stepping in place incorporates aspects of gait and may be a useful tool for locomotor training. The aim of this pilot study was to investigate the use of a single-tone and dual-tone metronome to cue stepping in place after hemiparetic stroke. Eight participants completed an uncued baseline stepping condition and two cued stepping conditions utilising a single-tone and ...

[Deep alkali burns: Evaluation of a two-step surgical strategy].

Science.gov (United States)

Devinck, F; Deveaux, C; Bennis, Y; Deken-Delannoy, V; Jeanne, M; Martinot-Duquennoy, V; Guerreschi, P; Pasquesoone, L

2018-04-10

Chemical burns are rare but often lead to deep cutaneous lesions. Alkali agents have a deep and long lasting penetrating power, causing burns that evolve over several days. The local treatment for these patients is excision of the wound and split thickness skin graft. Early excision and immediate skin grafting of alkali burns are more likely to be complicated by graft failure and delayed wound healing. We propose a two-step method that delays skin grafting until two-three days after burn wound excision. Our population included 25 controls and 16 cases. Men were predominant with a mean age of 41.9 years. In 78% of cases, burns were located on the lower limbs. The mean delay between the burn and excision was 16.5 days. In cases, the skin graft was performed at a mean of 11.3 days after the initial excision. We did not unveil any significant difference between both groups for the total skin surface affected, topography of the burns and the causal agent. Wound healing was significantly shorter in cases vs controls (37.5 days vs 50.3 days; P<0.025). Furthermore, we observed a decreased number of graft failures in cases vs controls (13.3% vs 46.7%; P=0.059). Our study shows the relevance of a two-step surgical strategy in patients with alkali chemical burns. Early excision followed by interval skin grafting is associated with quicker wound healing and decreased rate of graft failure. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A Million Steps: Developing a Health Promotion Program at the Workplace to Enhance Physical Activity.

Science.gov (United States)

González-Dominguez, María Eugenia; Romero-Sánchez, José Manuel; Ares-Camerino, Antonio; Marchena-Aparicio, Jose Carlos; Flores-Muñoz, Manuel; Infantes-Guzmán, Inés; León-Asuero, José Manuel; Casals-Martín, Fernando

2017-11-01

The workplace is a key setting for the prevention of occupational risks and for promoting healthy activities such as physical activity. Developing a physically active lifestyle results in many health benefits, improving both well-being and quality of life. This article details the experience of two Spanish companies that implemented a program to promote physical exercise in the workplace, called "A Million Steps." This program aimed to increase the physical activity of participants, challenging them to reach at least a million steps in a month through group walks. Participant workers reached the set goal and highlighted the motivational and interpersonal functions of the program.

Power generation options. Rehabilitation for life extension and cogeneration

International Nuclear Information System (INIS)

1993-01-01

The first step in evaluating a life extension or upgrading project is to determine the project's economic benefit to the utility. A screening study should be performed for as many candidate plants as are available; two of the most useful screening tools for rapid economic analysis of life extension possibilities are: Present Worth Revenue Requirements (PWRR) Analysis, and Life Cycle Cost (LCC) Analysis. (Examples of both methods are discussed). PWRR analysis considers only the expenses associated with operation of a plant or electrical system, and the revenue required to meet those expenses. The total revenue that may be received from the system is not considered in the analysis. The estimated costs for a base case (usually no rehabilitation or life extension) is compared to the operating costs of various alternatives, calculated over an operating life span of several years, and reduced to a Present Worth value, usually for the year in which the study started. If the PWRR of any alternative is estimated to be less than the base case, then an investment in the alternative plant equal to or less than this differential is a preferred economic choice. PWRR analysis is useful if future systems development and future gross revenue to the utility is difficult to estimate; it is also useful when comparing like technologies when differences in fuel supply and fuel cost are minimal

Improving the Elevated-Temperature Properties by Two-Step Heat Treatments in Al-Mn-Mg 3004 Alloys

Science.gov (United States)

Liu, K.; Ma, H.; Chen, X. Grant

2018-05-01

In the present work, two-step heat treatments with preheating at different temperatures (175 °C, 250 °C, and 330 °C) as the first step followed by the peak precipitation treatment (375 °C/48 h) as the second step were performed in Al-Mn-Mg 3004 alloys to study their effects on the formation of dispersoids and the evolution of the elevated-temperature strength and creep resistance. During the two-step heat treatments, the microhardness is gradually increased with increasing time to a plateau after 24 hours when first treated at 250 °C and 330 °C, while there is a minor decrease with time when first treated at 175 °C. Results show that both the yield strength (YS) and creep resistance at 300 °C reach the peak values after the two-step treatment of 250 °C/24 h + 375 °C/48 h. The formation of dispersoids is greatly related to the type and size of pre-existing Mg2Si precipitated during the preheating treatments. It was found that coarse rodlike β ' -Mg2Si strongly promotes the nucleation of dispersoids, while fine needle like β ″-Mg2Si has less influence. Under optimized two-step heat treatment and modified alloying elements, the YS at 300 °C can reach as high as 97 MPa with the minimum creep rate of 2.2 × 10-9 s-1 at 300 °C in Al-Mn-Mg 3004 alloys, enabling them as one of the most promising candidates in lightweight aluminum alloys for elevated-temperature applications.

Nonlinear Stability and Convergence of Two-Step Runge-Kutta Methods for Volterra Delay Integro-Differential Equations

Directory of Open Access Journals (Sweden)

Haiyan Yuan

2013-01-01

Full Text Available This paper introduces the stability and convergence of two-step Runge-Kutta methods with compound quadrature formula for solving nonlinear Volterra delay integro-differential equations. First, the definitions of (k,l-algebraically stable and asymptotically stable are introduced; then the asymptotical stability of a (k,l-algebraically stable two-step Runge-Kutta method with 0two-step Runge-Kutta method is algebraically stable and diagonally stable and its generalized stage order is p, then the method with compound quadrature formula is D-convergent of order at least min{p,ν}, where ν depends on the compound quadrature formula.

Two-Step Optimization for Spatial Accessibility Improvement: A Case Study of Health Care Planning in Rural China

Directory of Open Access Journals (Sweden)

Jing Luo

2017-01-01

Full Text Available A recent advancement in location-allocation modeling formulates a two-step approach to a new problem of minimizing disparity of spatial accessibility. Our field work in a health care planning project in a rural county in China indicated that residents valued distance or travel time from the nearest hospital foremost and then considered quality of care including less waiting time as a secondary desirability. Based on the case study, this paper further clarifies the sequential decision-making approach, termed “two-step optimization for spatial accessibility improvement (2SO4SAI.” The first step is to find the best locations to site new facilities by emphasizing accessibility as proximity to the nearest facilities with several alternative objectives under consideration. The second step adjusts the capacities of facilities for minimal inequality in accessibility, where the measure of accessibility accounts for the match ratio of supply and demand and complex spatial interaction between them. The case study illustrates how the two-step optimization method improves both aspects of spatial accessibility for health care access in rural China.

Stepping Theories of Active Logic with Two Kinds of Negation

Directory of Open Access Journals (Sweden)

Mikhail M. Vinkov

2017-01-01

Full Text Available This paper formulates a stepping theory formalism with two kinds of negation dealing with one of the areas of Active Logic, a new kind of logic aimed at performing practical tasks in real time knowledge-based AI systems. In addition to the standard logical negation, the proposed formalism uses the so-called subjective negation interpreted as inability to arrive at some conclusion through reasoning by a current time. The semantics of the proposed formalism is defined as an~argumentation structure.

Two-step frequency conversion for connecting distant quantum memories by transmission through an optical fiber

Science.gov (United States)

Tamura, Shuhei; Ikeda, Kohei; Okamura, Kotaro; Yoshii, Kazumichi; Hong, Feng-Lei; Horikiri, Tomoyuki; Kosaka, Hideo

2018-06-01

Long-distance quantum communication requires entanglement between distant quantum memories. For this purpose, photon transmission is necessary to connect the distant memories. Here, for the first time, we develop a two-step frequency conversion process (from a visible wavelength to a telecommunication wavelength and back) involving the use of independent two-frequency conversion media where the target quantum memories are nitrogen-vacancy centers in diamonds (with an emission/absorption wavelength of 637.2 nm), and experimentally characterize the performance of this process acting on light from an attenuated CW laser. A total conversion efficiency of approximately 7% is achieved. The noise generated in the frequency conversion processes is measured, and the signal-to-noise ratio is estimated for a single photon signal emitted by a nitrogen-vacancy (NV) center. The developed frequency conversion system has future applications via transmission through a long optical fiber channel at a telecommunication wavelength for a quantum repeater network.

A simple two-step method to fabricate highly transparent ITO/polymer nanocomposite films

International Nuclear Information System (INIS)

Liu, Haitao; Zeng, Xiaofei; Kong, Xiangrong; Bian, Shuguang; Chen, Jianfeng

2012-01-01

Highlights: ► A simple two-step method without further surface modification step was employed. ► ITO nanoparticles were easily to be uniformly dispersed in polymer matrix. ► ITO/polymer nanocomposite film had high transparency and UV/IR blocking properties. - Abstract: Transparent functional indium tin oxide (ITO)/polymer nanocomposite films were fabricated via a simple approach with two steps. Firstly, the functional monodisperse ITO nanoparticles were synthesized via a facile nonaqueous solvothermal method using bifunctional chemical agent (N-methyl-pyrrolidone, NMP) as the reaction solvent and surface modifier. Secondly, the ITO/acrylics polyurethane (PUA) nanocomposite films were fabricated by a simple sol-solution mixing method without any further surface modification step as often employed traditionally. Flower-like ITO nanoclusters with about 45 nm in diameter were mono-dispersed in ethyl acetate and each nanocluster was assembled by nearly spherical nanoparticles with primary size of 7–9 nm in diameter. The ITO nanoclusters exhibited an excellent dispersibility in polymer matrix of PUA, remaining their original size without any further agglomeration. When the loading content of ITO nanoclusters reached to 5 wt%, the transparent functional nanocomposite film featured a high transparency more than 85% in the visible light region (at 550 nm), meanwhile cutting off near-infrared radiation about 50% at 1500 nm and blocking UV ray about 45% at 350 nm. It could be potential for transparent functional coating materials applications.

Two-Step Multi-Physics Analysis of an Annular Linear Induction Pump for Fission Power Systems

Science.gov (United States)

Geng, Steven M.; Reid, Terry V.

2016-01-01

One of the key technologies associated with fission power systems (FPS) is the annular linear induction pump (ALIP). ALIPs are used to circulate liquid-metal fluid for transporting thermal energy from the nuclear reactor to the power conversion device. ALIPs designed and built to date for FPS project applications have not performed up to expectations. A unique, two-step approach was taken toward the multi-physics examination of an ALIP using ANSYS Maxwell 3D and Fluent. This multi-physics approach was developed so that engineers could investigate design variations that might improve pump performance. Of interest was to determine if simple geometric modifications could be made to the ALIP components with the goal of increasing the Lorentz forces acting on the liquid-metal fluid, which in turn would increase pumping capacity. The multi-physics model first calculates the Lorentz forces acting on the liquid metal fluid in the ALIP annulus. These forces are then used in a computational fluid dynamics simulation as (a) internal boundary conditions and (b) source functions in the momentum equations within the Navier-Stokes equations. The end result of the two-step analysis is a predicted pump pressure rise that can be compared with experimental data.

Grandparenting and adolescent adjustment in two-parent biological, lone-parent, and step-families.

Science.gov (United States)

Attar-Schwartz, Shalhevet; Tan, Jo-Pei; Buchanan, Ann; Flouri, Eirini; Griggs, Julia

2009-02-01

There is limited research on the links between grandparenting and adolescents' well-being, especially from the perspective of the adolescents. The study examined whether grandparent involvement varied in two-parent biological, lone-parent, and step-families and whether this had a different contribution to the emotional and behavioral adjustment of adolescents across different family structures. The study is based on a sample of 1,515 secondary school students (ages 11-16 years) from England and Wales who completed a structured questionnaire. Findings of hierarchical regression analyses showed that among the whole sample, greater grandparent involvement was associated with fewer emotional problems (p < .01) and with more prosocial behavior (p < .001). In addition, while there were no differences in the level of grandparent involvement across the different family structures, grandparent involvement was more strongly associated with reduced adjustment difficulties among adolescents from lone-parent and step-families than those from two-parent biological families. A possible implication is that the positive role of grandparent involvement in lone-parent and step- families should be more emphasized in family psychology. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Comparison of crossover and jab step start techniques for base stealing in baseball.

Science.gov (United States)

Miyanishi, Tomohisa; Endo, So; Nagahara, Ryu

2017-11-01

Base stealing is an important tactic for increasing the chance of scoring in baseball. This study aimed to compare the crossover step (CS) and jab step (JS) starts for base stealing start performance and to clarify the differences between CS and JS starts in terms of three-dimensional lower extremity joint kinetics. Twelve male baseball players performed CS and JS starts, during which their motion and the force they applied to the ground were simultaneously recorded using a motion-capture system and two force platforms. The results showed that the normalised average forward external power, the average forward-backward force exerted by the left leg, and the forward velocities of the whole body centre of gravity generated by both legs and the left leg were significantly higher for the JS start than for the CS start. Moreover, the positive work done by hip extension during the left leg push-off was two-times greater for the JS start than the CS start. In conclusion, this study has demonstrated that the jab step start may be the better technique for a base stealing start and that greater positive work produced by left hip extension is probably responsible for producing its larger forward ground reaction force.

A theoretical model investigation of peptide bond formation involving two water molecules in ribosome supports the two-step and eight membered ring mechanism

International Nuclear Information System (INIS)

Wang, Qiang; Gao, Jun; Zhang, Dongju; Liu, Chengbu

2015-01-01

Highlights: • We theoretical studied peptide bond formation reaction mechanism with two water molecules. • The first water molecule can decrease the reaction barriers by forming hydrogen bonds. • The water molecule mediated three-proton transfer mechanism is the favorable mechanism. • Our calculation supports the two-step and eight membered ring mechanism. - Abstract: The ribosome is the macromolecular machine that catalyzes protein synthesis. The kinetic isotope effect analysis reported by Strobel group supports the two-step mechanism. However, the destination of the proton originating from the nucleophilic amine is uncertain. A computational simulation of different mechanisms including water molecules is carried out using the same reaction model and theoretical level. Formation the tetrahedral intermediate with proton transfer from nucleophilic nitrogen, is the rate-limiting step when two water molecules participate in peptide bond formation. The first water molecule forming hydrogen bonds with O9′ and H15′ in the A site can decrease the reaction barriers. Combined with results of the solvent isotope effects analysis, we conclude that the three-proton transfer mechanism in which water molecule mediate the proton shuttle between amino and carbon oxygen in rate-limiting step is the favorable mechanism. Our results will shield light on a better understand the reaction mechanism of ribosome

Developing Boundary/PMI Solutions for Next-Step Fusion Devices

Science.gov (United States)

Guo, H. Y.; Leonard, A. W.; Thomas, D. M.; Allen, S. L.; Hill, D. N.; Unterberg, Z.

2014-10-01

The path towards next-step fusion development requires increased emphasis on the boundary/plasma-material interface. The new DIII-D Boundary/Plasma-Material Interactions (PMI) Center has been established to address these critical issues on a timescale relevant to the design of FNSF, adopting the following transformational approaches: (1) Develop and test advanced divertor configurations on DIII-D compatible with core plasma high performance operational scenarios in FNSF; (2) Validate candidate reactor PFC materials at reactor-relevant temperatures in DIII-D high-performance plasmas, in collaboration with the broad material research/development community; (3) Integrate validated boundary-materials interface with high performance plasmas to provide viable boundary/PMI solutions for next-step fusion devices. This program leverages unique DIII-D capabilities, promotes synergistic programs within the broad PMI community, including linear material research facilities. It will also enable us to build a compelling bridge for the US research on long-pulse facilities. Work supported by the US DOE under DE-FC02-04ER54698 and DE-AC52-07NA27344, DE-AC05-00OR2725.

Volunteers: A Challenge For Extension Workers: Developing Volunteer Leaders From Disadvantaged Families.

Science.gov (United States)

Partin, Minerva O.; And Others

A series of guidelines for use by Extension agents, as they involve socially and economically disadvantaged youth and adults in volunteer leadership roles in rural and urban Extension programs, is presented. Section headings are: Know Your Audience, Establish Rapport, Levels of Leadership, Leader Development, Leadership Roles, Volunteer…

Two-Step Injection Method for Collecting Digital Evidence in Digital Forensics

Directory of Open Access Journals (Sweden)

Nana Rachmana Syambas

2015-01-01

Full Text Available In digital forensic investigations, the investigators take digital evidence from computers, laptops or other electronic goods. There are many complications when a suspect or related person does not want to cooperate or has removed digital evidence. A lot of research has been done with the goal of retrieving data from flash memory or other digital storage media from which the content has been deleted. Unfortunately, such methods cannot guarantee that all data will be recovered. Most data can only be recovered partially and sometimes not perfectly, so that some or all files cannot be opened. This paper proposes the development of a new method for the retrieval of digital evidence called the Two-Step Injection method (TSI. It focuses on the prevention of the loss of digital evidence through the deletion of data by suspects or other parties. The advantage of this method is that the system works in secret and can be combined with other digital evidence applications that already exist, so that the accuracy and completeness of the resulting digital evidence can be improved. An experiment to test the effectiveness of the method was set up. The developed TSI system worked properly and had a 100% success rate.

Reconstructing Genetic Regulatory Networks Using Two-Step Algorithms with the Differential Equation Models of Neural Networks.

Science.gov (United States)

Chen, Chi-Kan

2017-07-26

The identification of genetic regulatory networks (GRNs) provides insights into complex cellular processes. A class of recurrent neural networks (RNNs) captures the dynamics of GRN. Algorithms combining the RNN and machine learning schemes were proposed to reconstruct small-scale GRNs using gene expression time series. We present new GRN reconstruction methods with neural networks. The RNN is extended to a class of recurrent multilayer perceptrons (RMLPs) with latent nodes. Our methods contain two steps: the edge rank assignment step and the network construction step. The former assigns ranks to all possible edges by a recursive procedure based on the estimated weights of wires of RNN/RMLP (RE RNN /RE RMLP ), and the latter constructs a network consisting of top-ranked edges under which the optimized RNN simulates the gene expression time series. The particle swarm optimization (PSO) is applied to optimize the parameters of RNNs and RMLPs in a two-step algorithm. The proposed RE RNN -RNN and RE RMLP -RNN algorithms are tested on synthetic and experimental gene expression time series of small GRNs of about 10 genes. The experimental time series are from the studies of yeast cell cycle regulated genes and E. coli DNA repair genes. The unstable estimation of RNN using experimental time series having limited data points can lead to fairly arbitrary predicted GRNs. Our methods incorporate RNN and RMLP into a two-step structure learning procedure. Results show that the RE RMLP using the RMLP with a suitable number of latent nodes to reduce the parameter dimension often result in more accurate edge ranks than the RE RNN using the regularized RNN on short simulated time series. Combining by a weighted majority voting rule the networks derived by the RE RMLP -RNN using different numbers of latent nodes in step one to infer the GRN, the method performs consistently and outperforms published algorithms for GRN reconstruction on most benchmark time series. The framework of two-step

Three-year randomized controlled clinical study of a one step universal adhesive and a two-step self-etch adhesive in Class II resin composite restorations

DEFF Research Database (Denmark)

van Dijken, Jan WV; Pallesen, Ulla

2017-01-01

Purpose: To evaluate in a randomized clinical evaluation the 3-year clinical durability of a one-step universal adhesive bonding system and compare it intraindividually with a 2-step self-etch adhesive in Class II restorations. Materials and Methods: Each of 57 participants (mean age 58.3 yr......) received at least two, as similar as possible, extended Class II restorations. The cavities in each of the 60 individual pairs of cavities were randomly distributed to the 1-step universal adhesive (All Bond Universal: AU) and the control 2-step self-etch adhesive (Optibond XTR: OX). A low shrinkage resin......) success rates (p>0.05). Annual failure rates were 1.8% and 2.6%, respectively.The main reason for failure was resin composite fracture. Conclusion: Class II resin composite restorations placed with a one-step universal adhesive showed good short time effectiveness....

Gender equality in rural development and agricultural extension in ...

African Journals Online (AJOL)

... (implementation, access to and control of resources) of women in maleheaded households, female-headed households and male-headed households in rural development and agricultural extension was the focus of this study. The district was purposively selected based on crop and livestock farming systems of the zone.

Preparation and optical properties of mesoporous TiO2 thin films by a two-step sol-gel technique

International Nuclear Information System (INIS)

Kartini, I.; Lu, G.Q.; Meredith, P.; Zhao, X.S.

2002-01-01

This paper concerns the preparation of mesoporous titania nanopowders and thin films for use in next generation photoelectrochemical solar cells. We have recently developed a novel method for preparing mesoporous TiO 2 powders using a Two-Step Sol-gel method (TSS). These materials have crystalline domains characteristic of anatase. The first step of the process involves the hydrolysis of titanium isopropoxide in a basic aqueous solution mediated by neutral surfactant. The solid product resulting from Step-1 is then treated in acidified ethanol solution containing a titanium precursor to yield anatase TiO 2 . The resultant powder exhibits a high surface area and large pore volume with uniform mesopores. Slurries made from the resultant powder of Steps 1 and 2 have been used to produce thin titania films on glass slides. The optical and structural properties of these films have been compared to the films made of a commercial titania (Degussa P25, BASF). We will discuss these properties with respect to the possible use of such mesoporous titania films as the wide band gap semiconductor in dye-sensitized nanocrystalline TiO 2 solar cells

Rapid Two-Step Procedure for Large-Scale Purification of Pediocin-Like Bacteriocins and Other Cationic Antimicrobial Peptides from Complex Culture Medium

Science.gov (United States)

Uteng, Marianne; Hauge, Håvard Hildeng; Brondz, Ilia; Nissen-Meyer, Jon; Fimland, Gunnar

2002-01-01

A rapid and simple two-step procedure suitable for both small- and large-scale purification of pediocin-like bacteriocins and other cationic peptides has been developed. In the first step, the bacterial culture was applied directly on a cation-exchange column (1-ml cation exchanger per 100-ml cell culture). Bacteria and anionic compounds passed through the column, and cationic bacteriocins were subsequently eluted with 1 M NaCl. In the second step, the bacteriocin fraction was applied on a low-pressure, reverse-phase column and the bacteriocins were detected as major optical density peaks upon elution with propanol. More than 80% of the activity that was initially in the culture supernatant was recovered in both purification steps, and the final bacteriocin preparation was more than 90% pure as judged by analytical reverse-phase chromatography and capillary electrophoresis. PMID:11823243

Biodiesel production from microalgae Spirulina maxima by two step process: Optimization of process variable

Directory of Open Access Journals (Sweden)

M.A. Rahman

2017-04-01

Full Text Available Biodiesel from green energy source is gaining tremendous attention for ecofriendly and economically aspect. In this investigation, a two-step process was developed for the production of biodiesel from microalgae Spirulina maxima and determined best operating conditions for the steps. In the first stage, acid esterification was conducted to lessen acid value (AV from 10.66 to 0.51 mgKOH/g of the feedstock and optimal conditions for maximum esterified oil yielding were found at molar ratio 12:1, temperature 60°C, 1% (wt% H2SO4, and mixing intensity 400 rpm for a reaction time of 90 min. The second stage alkali transesterification was carried out for maximum biodiesel yielding (86.1% and optimal conditions were found at molar ratio 9:1, temperature 65°C, mixing intensity 600 rpm, catalyst concentration 0.75% (wt% KOH for a reaction time of 20 min. Biodiesel were analyzed according to ASTM standards and results were within standards limit. Results will helpful to produce third generation algal biodiesel from microalgae Spirulina maxima in an efficient manner.

Two-step adaptive management for choosing between two management actions.

Science.gov (United States)

Moore, Alana L; Walker, Leila; Runge, Michael C; McDonald-Madden, Eve; McCarthy, Michael A

2017-06-01

Adaptive management is widely advocated to improve environmental management. Derivations of optimal strategies for adaptive management, however, tend to be case specific and time consuming. In contrast, managers might seek relatively simple guidance, such as insight into when a new potential management action should be considered, and how much effort should be expended on trialing such an action. We constructed a two-time-step scenario where a manager is choosing between two possible management actions. The manager has a total budget that can be split between a learning phase and an implementation phase. We use this scenario to investigate when and how much a manager should invest in learning about the management actions available. The optimal investment in learning can be understood intuitively by accounting for the expected value of sample information, the benefits that accrue during learning, the direct costs of learning, and the opportunity costs of learning. We find that the optimal proportion of the budget to spend on learning is characterized by several critical thresholds that mark a jump from spending a large proportion of the budget on learning to spending nothing. For example, as sampling variance increases, it is optimal to spend a larger proportion of the budget on learning, up to a point: if the sampling variance passes a critical threshold, it is no longer beneficial to invest in learning. Similar thresholds are observed as a function of the total budget and the difference in the expected performance of the two actions. We illustrate how this model can be applied using a case study of choosing between alternative rearing diets for hihi, an endangered New Zealand passerine. Although the model presented is a simplified scenario, we believe it is relevant to many management situations. Managers often have relatively short time horizons for management, and might be reluctant to consider further investment in learning and monitoring beyond collecting data

Two-step adaptive management for choosing between two management actions

Science.gov (United States)

Moore, Alana L.; Walker, Leila; Runge, Michael C.; McDonald-Madden, Eve; McCarthy, Michael A

2017-01-01

Adaptive management is widely advocated to improve environmental management. Derivations of optimal strategies for adaptive management, however, tend to be case specific and time consuming. In contrast, managers might seek relatively simple guidance, such as insight into when a new potential management action should be considered, and how much effort should be expended on trialing such an action. We constructed a two-time-step scenario where a manager is choosing between two possible management actions. The manager has a total budget that can be split between a learning phase and an implementation phase. We use this scenario to investigate when and how much a manager should invest in learning about the management actions available. The optimal investment in learning can be understood intuitively by accounting for the expected value of sample information, the benefits that accrue during learning, the direct costs of learning, and the opportunity costs of learning. We find that the optimal proportion of the budget to spend on learning is characterized by several critical thresholds that mark a jump from spending a large proportion of the budget on learning to spending nothing. For example, as sampling variance increases, it is optimal to spend a larger proportion of the budget on learning, up to a point: if the sampling variance passes a critical threshold, it is no longer beneficial to invest in learning. Similar thresholds are observed as a function of the total budget and the difference in the expected performance of the two actions. We illustrate how this model can be applied using a case study of choosing between alternative rearing diets for hihi, an endangered New Zealand passerine. Although the model presented is a simplified scenario, we believe it is relevant to many management situations. Managers often have relatively short time horizons for management, and might be reluctant to consider further investment in learning and monitoring beyond collecting data

A two-step method for fast and reliable EUV mask metrology

Science.gov (United States)

Helfenstein, Patrick; Mochi, Iacopo; Rajendran, Rajeev; Yoshitake, Shusuke; Ekinci, Yasin

2017-03-01

One of the major obstacles towards the implementation of extreme ultraviolet lithography for upcoming technology nodes in semiconductor industry remains the realization of a fast and reliable detection methods patterned mask defects. We are developing a reflective EUV mask-scanning lensless imaging tool (RESCAN), installed at the Swiss Light Source synchrotron at the Paul Scherrer Institut. Our system is based on a two-step defect inspection method. In the first step, a low-resolution defect map is generated by die to die comparison of the diffraction patterns from areas with programmed defects, to those from areas that are known to be defect-free on our test sample. In a later stage, a die to database comparison will be implemented in which the measured diffraction patterns will be compared to those calculated directly from the mask layout. This Scattering Scanning Contrast Microscopy technique operates purely in the Fourier domain without the need to obtain the aerial image and, given a sufficient signal to noise ratio, defects are found in a fast and reliable way, albeit with a location accuracy limited by the spot size of the incident illumination. Having thus identified rough locations for the defects, a fine scan is carried out in the vicinity of these locations. Since our source delivers coherent illumination, we can use an iterative phase-retrieval method to reconstruct the aerial image of the scanned area with - in principle - diffraction-limited resolution without the need of an objective lens. Here, we will focus on the aerial image reconstruction technique and give a few examples to illustrate the capability of the method.

In situ synthesis carbonated hydroxyapatite layers on enamel slices with acidic amino acids by a novel two-step method

International Nuclear Information System (INIS)

Wu, Xiaoguang; Zhao, Xu; Li, Yi; Yang, Tao; Yan, Xiujuan; Wang, Ke

2015-01-01

hydroxyapatite (CHA) remineralization layer on an enamel slice was completed in a novel, biomimetic two-step method. The results show that the rod-like carbonated hydroxyapatite grows into bundles, which are similar in size and appearance to prisms in human enamel, when using the two-step method with either aspartic acid or acidic glutamate (20.00 mmol/L). Compared with images B and C, the length of enamel prisms in the artificially repaired area is much longer than the enamel prisms in the unrepaired area. - Highlights: • A novel method of hydroxyapatite remineralization on enamel slices was developed. • CaCO 3 layer on the demineralized enamel surface was synthesized in the first step. • Hydroxyapatite was synthesized with CaCO 3 as a sacrificial template and reactant. • The appearance of hydroxyapatite crystals is similar to the prisms in human enamel

In situ synthesis carbonated hydroxyapatite layers on enamel slices with acidic amino acids by a novel two-step method

Energy Technology Data Exchange (ETDEWEB)

Wu, Xiaoguang [Department of Pediatric Dentistry, The Hospital of Stomatology, Jilin University, Changchun 130021 (China); Zhao, Xu [College of Chemistry, Jilin University, Changchun 130021 (China); Li, Yi, E-mail: lyi99@jlu.edu.cn [Department of Pediatric Dentistry, The Hospital of Stomatology, Jilin University, Changchun 130021 (China); Yang, Tao [Department of Stomatology, Children' s Hospital of Changchun, 130051 (China); Yan, Xiujuan; Wang, Ke [Department of Pediatric Dentistry, The Hospital of Stomatology, Jilin University, Changchun 130021 (China)

2015-09-01

carbonated hydroxyapatite (CHA) remineralization layer on an enamel slice was completed in a novel, biomimetic two-step method. The results show that the rod-like carbonated hydroxyapatite grows into bundles, which are similar in size and appearance to prisms in human enamel, when using the two-step method with either aspartic acid or acidic glutamate (20.00 mmol/L). Compared with images B and C, the length of enamel prisms in the artificially repaired area is much longer than the enamel prisms in the unrepaired area. - Highlights: • A novel method of hydroxyapatite remineralization on enamel slices was developed. • CaCO{sub 3} layer on the demineralized enamel surface was synthesized in the first step. • Hydroxyapatite was synthesized with CaCO{sub 3} as a sacrificial template and reactant. • The appearance of hydroxyapatite crystals is similar to the prisms in human enamel.

Eight-year randomized clinical evaluation of Class II nanohybrid resin composite restorations bonded with a one-step self-etch or a two-step etch-and-rinse adhesive

DEFF Research Database (Denmark)

van Dijken, Jan WV; Pallesen, Ulla

2015-01-01

(13.5 %) and nine in the two-step etch-and-rinse group (13.0 %). This resulted in nonsignificant different annual failure rates of 1.69 and 1.63 %, respectively. Fracture of restoration was the main reason for failure. Conclusion: Good clinical performance was shown during the 8-year evaluation....... Results: One hundred and fifty-eight restorations were evaluated after 8 years. Three participants with five restorations (three Xeno III, two Excite) were registered as dropouts. Twenty-one failed restorations (13.3 %) were observed during the follow-up. Twelve in the one-step self-etch adhesive group...... and no significant difference in overall clinical performance between the two adhesives. Fracture was the main reason for failure. Clinical relevance: The one-step self-etch adhesive showed a good long-term clinical effectiveness in combination with the nanohybrid resin composite in Class II restorations....

Development of a real time activity monitoring Android application utilizing SmartStep.

Science.gov (United States)

Hegde, Nagaraj; Melanson, Edward; Sazonov, Edward

2016-08-01

Footwear based activity monitoring systems are becoming popular in academic research as well as consumer industry segments. In our previous work, we had presented developmental aspects of an insole based activity and gait monitoring system-SmartStep, which is a socially acceptable, fully wireless and versatile insole. The present work describes the development of an Android application that captures the SmartStep data wirelessly over Bluetooth Low energy (BLE), computes features on the received data, runs activity classification algorithms and provides real time feedback. The development of activity classification methods was based on the the data from a human study involving 4 participants. Participants were asked to perform activities of sitting, standing, walking, and cycling while they wore SmartStep insole system. Multinomial Logistic Discrimination (MLD) was utilized in the development of machine learning model for activity prediction. The resulting classification model was implemented in an Android Smartphone. The Android application was benchmarked for power consumption and CPU loading. Leave one out cross validation resulted in average accuracy of 96.9% during model training phase. The Android application for real time activity classification was tested on a human subject wearing SmartStep resulting in testing accuracy of 95.4%.

Comparison between two methodologies for uniformity correction of extensive reference sources

International Nuclear Information System (INIS)

Junior, Iremar Alves S.; Siqueira, Paulo de T.D.; Vivolo, Vitor; Potiens, Maria da Penha A.; Nascimento, Eduardo

2016-01-01

This article presents the procedures to obtain the uniformity correction factors for extensive reference sources proposed by two different methodologies. The first methodology is presented by the Good Practice Guide of Nº 14 of the NPL, which provides a numerical correction. The second one uses the radiation transport code, MCNP5, to obtain the correction factor. Both methods retrieve very similar corrections factor values, with a maximum deviation of 0.24%. (author)

Theoretical aspects of several successive two-step redox mechanisms in protein-film cyclic staircase voltammetry

International Nuclear Information System (INIS)

Gulaboski, Rubin; Kokoškarova, Pavlinka; Mitrev, Saša

2012-01-01

Highlights: ► Theoretical models for 2e− successive mechanisms are considered. ► The models are compatible for various metal-containing redox proteins. ► Diagnostic criteria are provided to recognize the particular redox mechanism. - Abstract: Protein-film voltammetry (PFV) is a versatile tool designed to provide insight into the enzymes physiological functions by studying the redox properties of various oxido-reductases with suitable voltammetric technique. The determination of the thermodynamic and kinetic parameters relevant to protein's physiological properties is achieved via methodologies established from theoretical considerations of various mechanisms in PFV. So far, the majority of the mathematical models in PFV have been developed for redox proteins undergoing a single-step electron transfer reactions. However, there are many oxido-reductases containing quinone moieties or polyvalent ions of transition metals like Mo, Mn, W, Fe or Co as redox centers, whose redox chemistry can be described only via mathematical models considering successive two-step electron transformation. In this work we consider theoretically the protein-film redox mechanisms of the EE (Electrochemical–Electrochemical), ECE (Electrochemical–Chemical–Electrochemical), and EECat (Electrochemical–Electrochemical–Catalytic) systems under conditions of cyclic staircase voltammetry. We also propose methodologies to determine the kinetics of electron transfer steps by all considered mechanisms. The experimentalists working with PFV can get large benefits from the simulated voltammograms given in this work.

Two-step preparation of nano-scaled magnetic chitosan particles using Triton X-100 reversed-phase water-in-oil microemulsion system

International Nuclear Information System (INIS)

Zhou, Zhengkun; Jiang, Feihong; Lee, Tung-Ching; Yue, Tianli

2013-01-01

Highlights: •A new two-step route for nano-scaled magnetic chitosan particles preparation. •Triton X-100 reversed-phase microemulsion system was used for chitosan coating. •Narrow size distribution of magnetic chitosan nanoparticles was achieved. •Quantitative evaluation of recoverability for the magnetic chitosan nanoparticles. -- Abstract: A new two-step route for the preparation of nano-scaled magnetic chitosan particles has been developed, different from reported one-step in situ preparation and two-step preparation method of reversed-phase suspension, Triton X-100 reversed-phase water-in-oil microemulsion encapsulation method was employed in coating the pre-prepared Fe 3 O 4 nanoparticles with chitosan. The resultant magnetic chitosan particles owned a narrow size distribution ranging from 50 to 92 nm. X-ray diffraction patterns (XRD) indicated that the chitosan coating procedure did not change the spinal structure of Fe 3 O 4 magnetic nanoparticles. The results of Fourier transform infrared (FTIR) analysis and thermogravimetric analysis (TGA) demonstrated that the chitosan was coated on Fe 3 O 4 nanoparticles and its average mass content was ∼50%. The saturated magnetization of the magnetic Fe 3 O 4 /chitosan nanoparticles reached 18.62 emu/g, meanwhile, the nanoparticles showed the characteristics of superparamagnetism. The magnetic chitosan nanoparticles showed a high recoverability of 99.99% in 10 min when pH exceeded 4. The results suggested that the as-prepared magnetic chitosan particles were nano-scaled with a narrow size distribution and a high recoverability

Culture and the Sequence of Steps in Theory of Mind Development

Science.gov (United States)

Shahaeian, Ameneh; Peterson, Candida C.; Slaughter, Virginia; Wellman, Henry M.

2011-01-01

To examine cultural contrasts in the ordered sequence of conceptual developments leading to theory of mind (ToM), we compared 135 3- to 6-year-olds (77 Australians; 58 Iranians) on an established 5-step ToM scale (Wellman & Liu, 2004). There was a cross-cultural difference in the sequencing of ToM steps but not in overall rates of ToM mastery.…

From raw material to dish: pasta quality step by step.

Science.gov (United States)

Sicignano, Angelo; Di Monaco, Rossella; Masi, Paolo; Cavella, Silvana

2015-10-01

Pasta is a traditional Italian cereal-based food that is popular worldwide because of its convenience, versatility, sensory and nutritional value. The aim of this review is to present a step-by-step guide to facilitate the understanding of the most important events that can affect pasta characteristics, directing the reader to the appropriate production steps. Owing to its unique flavor, color, composition and rheological properties, durum wheat semolina is the best raw material for pasta production. Although pasta is traditionally made from only two ingredients, sensory quality and chemical/physical characteristics of the final product may vary greatly. Starting from the same ingredients, there are a lot of different events in each step of pasta production that can result in the development of varieties of pasta with different characteristics. In particular, numerous studies have demonstrated the importance of temperature and humidity conditions of the pasta drying operation as well as the significance of the choice of raw material and operating conditions on pasta quality. © 2015 Society of Chemical Industry.

Comparison of microbial community shifts in two parallel multi-step drinking water treatment processes.

Science.gov (United States)

Xu, Jiajiong; Tang, Wei; Ma, Jun; Wang, Hong

2017-07-01

Drinking water treatment processes remove undesirable chemicals and microorganisms from source water, which is vital to public health protection. The purpose of this study was to investigate the effects of treatment processes and configuration on the microbiome by comparing microbial community shifts in two series of different treatment processes operated in parallel within a full-scale drinking water treatment plant (DWTP) in Southeast China. Illumina sequencing of 16S rRNA genes of water samples demonstrated little effect of coagulation/sedimentation and pre-oxidation steps on bacterial communities, in contrast to dramatic and concurrent microbial community shifts during ozonation, granular activated carbon treatment, sand filtration, and disinfection for both series. A large number of unique operational taxonomic units (OTUs) at these four treatment steps further illustrated their strong shaping power towards the drinking water microbial communities. Interestingly, multidimensional scaling analysis revealed tight clustering of biofilm samples collected from different treatment steps, with Nitrospira, the nitrite-oxidizing bacteria, noted at higher relative abundances in biofilm compared to water samples. Overall, this study provides a snapshot of step-to-step microbial evolvement in multi-step drinking water treatment systems, and the results provide insight to control and manipulation of the drinking water microbiome via optimization of DWTP design and operation.

Finite cluster renormalization and new two step renormalization group for Ising model

International Nuclear Information System (INIS)

Benyoussef, A.; El Kenz, A.

1989-09-01

New types of renormalization group theory using the generalized Callen identities are exploited in the study of the Ising model. Another type of two-step renormalization is proposed. Critical couplings and critical exponents y T and y H are calculated by these methods for square and simple cubic lattices, using different size clusters. (author). 17 refs, 2 tabs

Controllable two-step growth and photoluminescence of waterweed-like SnO{sub 2} nanowires

Energy Technology Data Exchange (ETDEWEB)

Chang, Li-Wei, E-mail: liwei0509@gmail.com [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Huang, Meng-Wen [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan (China); Li, Chung-Tien [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Shih, Han C., E-mail: hcshih@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan (China); Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Department of Chemical and Materials Engineering, Chinese Culture University, Taipei 111, Taiwan (China)

2013-08-15

Waterweed-like SnO{sub 2} nanowires (NWs) were synthesized via a two-step thermal chemical vapor deposition (TVCD) process. Nanowhiskers with enlarged surface-to-volume ratio can be grown on NWs accurately, because of the product synthesized via the two-step process. These NWs and nanowhiskers with unusual [1 0 1] and [121{sup ¯}] growth directions have very straight and uniform diameters and lengths. Photoluminescence shows that waterweed-like SnO{sub 2} NWs have three prominent emission bands at 540, 612, and 668 nm. The waterweed-like SnO{sub 2} can be applied in optoelectronic devices and potential applications to lithium-ion batteries, because of its high surface-to-volume ratio and high electric capacity properties.

Extensions of conformal symmetry in two-dimensional quantum field theory

International Nuclear Information System (INIS)

Schoutens, C.J.M.

1989-01-01

Conformal symmetry extensions in a two-dimensional quantum field theory are the main theme of the work presented in this thesis. After a brief exposition of the formalism for conformal field theory, the motivation for studying extended symmetries in conformal field theory is presented in some detail. Supersymmetric extensions of conformal symmetry are introduced. An overview of the algebraic superconformal symmetry is given. The relevance of higher-spin bosonic extensions of the Virasoro algebra in relation to the classification program for so-called rational conformal theories is explained. The construction of a large class of bosonic extended algebras, the so-called Casimir algebras, are presented. The representation theory of these algebras is discussed and a large class of new unitary models is identified. The superspace formalism for O(N)-extended superconformal quantum field theory is presented. It is shown that such theories exist for N ≤ 4. Special attention is paid to the case N = 4 and it is shown that the allowed central charges are c(n + ,n - ) = 6n + n - /(n + ,n - ), where n + and n - are positive integers. A different class of so(N)-extended superconformal algebras is analyzed. The representation theory is studied and it is established that certain free field theories provide realizations of the algebras with level S = 1. Finally the so-called BRST construction for extended conformal algebras is considered. A nilpotent BRST charge is constructed for a large class of algebras, which contains quadratically nonlinear algebras that fall outside the traditional class if finitely generated Lie (super)algebras. The results are especially relevant for the construction of string models based on extended conformal symmetry. (author). 118 refs.; 7 tabs

Community Development and Divergent Forces in Philippine State Universities and Colleges: Developing a Protocol in Evaluating Extension Projects Towards Community Empowerment

Directory of Open Access Journals (Sweden)

Dexter S. Ontoy

2016-11-01

Full Text Available Divergent paradigms operate in State Universities and Colleges SUCs, which influence the performance of extension projects towards attainment of full empowerment as the ultimate goal implied by the universally-accepted definition of community development. In particular, a livelihood and environment project of Cebu Normal University (CNU implemented in Caputatan Norte, Medillin, Cebu, Philippines was assessed based on five (5 primary parameters and two (2 secondary parameters. A novel protocol using Delphi Method shows was developed and used for this particular study, which could be adapted in evaluating the performance of community extension projects. In this particular case, the performance of CNU livelihood and environment project falls between ―demonstration‖ and ―community organizing‖. The evaluation shows that there is still a need to reinforce activities to the ultimate goal. However, it is also implied that the secondary parameters are more robust indicators in assessing the outcomes of the project implementation towards full community empowerment.

With or without you: consumer acceptance of two national brand portfolio extension options

NARCIS (Netherlands)

Bakker, Diederich; Nenycz-Thiel, Magda

2011-01-01

The aim of this paper is to investigate which portfolio extension option: either a cheaper subbrand or a private label endorsed by the national brand is better from the consumer perspective. Two hypothetical product concepts from a leading beer brand were tested among Dutch consumers. The findings

Stepping Stones to Resiliency following a community-based two-generation Canadian preschool programme.

Science.gov (United States)

Ginn, Carla S; Benzies, Karen M; Keown, Leslie Anne; Raffin Bouchal, Shelley; Thurston, Wilfreda E Billlie

2018-05-01

Early intervention programmes are designed to address complex inequities for Canadian families living with low income, affecting social relationships, well-being and mental health. However, there is limited understanding of resiliency and change in families living with low income over time. We conducted a mixed methods study with recent immigrant, other Canadian-born, and Aboriginal families living with low income, who attended a two-generation preschool programme (CUPS One World) between 2002 and 2008. The aim of this study was to develop an understanding of the processes of change. We included 134 children and their caregivers living with low income, and experiencing mental health problems, addiction or social isolation. Children's receptive language, a proxy for school readiness, was measured at programme intake, exit, and age 10 years using the Peabody Picture Vocabulary Test 3rd Edition (PPVT-III). In Phase I (quantitative), we identified children with receptive language scores in the top and bottom 25th percentile, informing participant selection for Phase II. In Phase II (qualitative), we engaged in constructivist grounded theory to explore experiences of 14 biological mothers, after their children (n = 25) reached age 10 years. Interviews were conducted between June and September 2015. The core category, Stepping Stones to Resiliency, encompassed Perceptions of Family, Moving Forward, Achieving Goals, and Completely Different. Perceptions of Family influenced families' capabilities to move across the Stepping Stones to Resiliency. Stepping Stones to Resiliency provides a lens from which to view others in their daily challenges to break free of painful intergenerational cycles. It is a reminder of our struggle, our shared humanness, and that movement towards resiliency is more difficult for some than others. Our findings challenge traditional episodic, biomedical treatment paradigms for low-income families also experiencing intergenerational cycles of

Velocity-space observation regions of high-resolution two-step reaction gamma-ray spectroscopy

DEFF Research Database (Denmark)

Salewski, Mirko; Nocente, M.; Gorini, G.

2015-01-01

High-resolution γ-ray spectroscopy (GRS) measurements resolve spectral shapes of Dopplerbroadened γ-rays. We calculate weight functions describing velocity-space sensitivities of any two-step reaction GRS measurements in magnetized plasmas using the resonant nuclear reaction 9Be(α, nγ)12C...

Type 1 Does The Two-Step: Type 1 Secretion Substrates With A Functional Periplasmic Intermediate.

Science.gov (United States)

Smith, Timothy J; Sondermann, Holger; O'Toole, George A

2018-06-04

Bacteria have evolved several secretion strategies for polling and responding to environmental flux and insult. Of these, the type 1 secretion system (T1SS) is known to secrete an array of biologically diverse proteins - from small < 10 kDa bacteriocins to gigantic adhesins with a mass over 1 MDa. For the last several decades T1SS have been characterized as a one-step translocation strategy whereby the secreted substrate is transported directly into the extracellular environment from the cytoplasm with no periplasmic intermediate. Recent phylogenetic, biochemical, and genetic evidence point to a distinct sub-group of T1SS machinery linked with a bacterial transglutaminase-like cysteine proteinase (BTLCP), which uses a two-step secretion mechanism. BTLCP-linked T1SS transport a class of repeats-in-toxin (RTX) adhesins that are critical for biofilm formation. The prototype of this RTX adhesin group, LapA of Pseudomonas fluorescens Pf0-1, uses a novel N-terminal retention module to anchor the adhesin at the cell surface as a secretion intermediate threaded through the outer membrane-localized, TolC-like protein LapE. This secretion intermediate is post-translationally cleaved by the BTLCP family LapG protein to release LapA from its cognate T1SS pore. Thus, secretion of LapA and related RTX adhesins into the extracellular environment appears to be a T1SS-mediated, two-step process that involves a periplasmic intermediate. In this review, we contrast the T1SS machinery and substrates of the BLTCP-linked two-step secretion process with those of the classical one-step T1SS to better understand the newly recognized and expanded role of this secretion machinery. Copyright © 2018 American Society for Microbiology.

Comparison of enamel bond fatigue durability between universal adhesives and two-step self-etch adhesives: Effect of phosphoric acid pre-etching.

Science.gov (United States)

Suda, Shunichi; Tsujimoto, Akimasa; Barkmeier, Wayne W; Nojiri, Kie; Nagura, Yuko; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

2018-03-30

The effect of phosphoric acid pre-etching on enamel bond fatigue durability of universal adhesives and two-step self-etch adhesives was investigated. Four universal adhesives and three two-step self-etch adhesives were used. The initial shear bond strengths and shear fatigue strengths to enamel with and without phosphoric acid pre-etching using the adhesives were determined. SEM observations were also conducted. Phosphoric acid pre-etching of enamel was found to increase the bond fatigue durability of universal adhesives, but its effect on two-step self-etch adhesives was material-dependent. In addition, some universal adhesives with phosphoric acid pre-etching showed similar bond fatigue durability to the two-step self-etch adhesives, although the bond fatigue durability of universal adhesives in self-etch mode was lower than that of the two-step self-etch adhesives. Phosphoric acid pre-etching enhances enamel bond fatigue durability of universal adhesives, but the effect of phosphoric acid pre-etching on the bond fatigue durability of two-step self-etch adhesives was material-dependent.

ORDERED POROUS ANODIC ALUMINUM OXIDE FILMS MADE BY TWO-STEP ANODIZATION

OpenAIRE

HANSONG XUE; HUAJI LI; YU YI; HUIFANG HU

2007-01-01

Porous Anodic Aluminum Oxide (AAO) films were prepared by two-step anodizing in sulfuric and oxalic acid solutions and observed by transmission electron microscope (TEM) and X-ray diffraction. The results show that the form of AAO film is affected by the varieties and concentrations of electrolyte, anodizing voltage, and the anodizing time; the formation and evolution processes of the AAO film are relative with the anodizing voltage severely, and the appropriate voltage is helpful to the orde...

Lyondell develops one step isobutylene process

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that Lyondell Petrochemical Co., Houston, has developed a one step process to convert normal butylenes to isobutylene, a key component of methyl tertiary butyl ether (MTBE). MTBE is expected to become the additive of choice among U.S. refiners to blend oxygenated gasolines required by 1990 amendments to the Clean Air Act. Lyondell Pres. and Chief Executive Officer Bob Gower the the new process could help assure adequate supplies of MTBE to meet U.S. demand for cleaner burning fuels. Lyondell estimates the capital cost of building a grassroots plant to produce isobutylene with the new process would be less than half the cost of a grassroot plant to produce isobutylene with existing technology starting with normal butane

Two-Step Proximal Gradient Algorithm for Low-Rank Matrix Completion

Directory of Open Access Journals (Sweden)

Qiuyu Wang

2016-06-01

Full Text Available In this paper, we  propose a two-step proximal gradient algorithm to solve nuclear norm regularized least squares for the purpose of recovering low-rank data matrix from sampling of its entries. Each iteration generated by the proposed algorithm is a combination of the latest three points, namely, the previous point, the current iterate, and its proximal gradient point. This algorithm preserves the computational simplicity of classical proximal gradient algorithm where a singular value decomposition in proximal operator is involved. Global convergence is followed directly in the literature. Numerical results are reported to show the efficiency of the algorithm.

Two-step photoionization of hydrogen atoms in interplanetary space

International Nuclear Information System (INIS)

Gruntman, M.A.

1990-01-01

Photoionization is one of the key processes which determine the properties of fluxes of neutral atoms in interplanetary space. A new two-step channel (called indirect) of photoionization of hydrogen atoms is proposed. Hydrogen atoms are at first excited to states with principal quantum number n > 2, then decay to metastable H(2S) states, where they can be photoionized. Competing processes due to the interaction with solar wind plasma and solar radiation are considered and the photoionization rate through the proposed indirect channel is calculated. This rate depends on distance from the Sun as ∝ 1/R 4 at large distances (R > 1-2 a.u.) and as ∝ 1/R 2 at close approaches, where it is higher than the rate of direct photoionization. (author)

Two step esterification-transesterification process of wet greasy sewage sludge for biodiesel production.

Science.gov (United States)

Urrutia, C; Sangaletti-Gerhard, N; Cea, M; Suazo, A; Aliberti, A; Navia, R

2016-01-01

Sewage sludge generated in municipal wastewater treatment plants was used as a feedstock for biodiesel production via esterification/transesterification in a two-step process. In the first esterification step, greasy and secondary sludge were tested using acid and enzymatic catalysts. The results indicate that both catalysts performed the esterification of free fatty acids (FFA) simultaneously with the transesterification of triacylglycerols (TAG). Acid catalyst demonstrated better performance in FFA esterification compared to TAG transesterification, while enzymatic catalyst showed the ability to first hydrolyze TAG in FFA, which were esterified to methyl esters. In addition, FAME concentration using greasy sludge were higher (63.9% and 58.7%), compared with those of secondary sludge (11% and 16%), using acid and enzymatic catalysts, respectively. Therefore, only greasy sludge was used in the second step of alkaline transesterification. The alkaline transesterification of the previously esterified greasy sludge reached a maximum FAME concentration of 65.4% when using acid catalyst. Copyright © 2015 Elsevier Ltd. All rights reserved.

Turning an Extension Aide into an Extension Agent

Science.gov (United States)

Seevers, Brenda; Dormody, Thomas J.

2010-01-01

For any organization to remain sustainable, a renewable source of faculty and staff needs to be available. The Extension Internship Program for Juniors and Seniors in High School is a new tool for recruiting and developing new Extension agents. Students get "hands on" experience working in an Extension office and earn college credit…

Amino Acids Regulate mTORC1 by an Obligate Two-step Mechanism*

Science.gov (United States)

Dyachok, Julia; Earnest, Svetlana; Iturraran, Erica N.; Cobb, Melanie H.

2016-01-01

The mechanistic target of rapamycin complex 1 (mTORC1) coordinates cell growth with its nutritional, hormonal, energy, and stress status. Amino acids are critical regulators of mTORC1 that permit other inputs to mTORC1 activity. However, the roles of individual amino acids and their interactions in mTORC1 activation are not well understood. Here we demonstrate that activation of mTORC1 by amino acids includes two discrete and separable steps: priming and activation. Sensitizing mTORC1 activation by priming amino acids is a prerequisite for subsequent stimulation of mTORC1 by activating amino acids. Priming is achieved by a group of amino acids that includes l-asparagine, l-glutamine, l-threonine, l-arginine, l-glycine, l-proline, l-serine, l-alanine, and l-glutamic acid. The group of activating amino acids is dominated by l-leucine but also includes l-methionine, l-isoleucine, and l-valine. l-Cysteine predominantly inhibits priming but not the activating step. Priming and activating steps differ in their requirements for amino acid concentration and duration of treatment. Priming and activating amino acids use mechanisms that are distinct both from each other and from growth factor signaling. Neither step requires intact tuberous sclerosis complex of proteins to activate mTORC1. Concerted action of priming and activating amino acids is required to localize mTORC1 to lysosomes and achieve its activation. PMID:27587390

Two-Step Time of Arrival Estimation for Pulse-Based Ultra-Wideband Systems

Directory of Open Access Journals (Sweden)

H. Vincent Poor

2008-05-01

Full Text Available In cooperative localization systems, wireless nodes need to exchange accurate position-related information such as time-of-arrival (TOA and angle-of-arrival (AOA, in order to obtain accurate location information. One alternative for providing accurate position-related information is to use ultra-wideband (UWB signals. The high time resolution of UWB signals presents a potential for very accurate positioning based on TOA estimation. However, it is challenging to realize very accurate positioning systems in practical scenarios, due to both complexity/cost constraints and adverse channel conditions such as multipath propagation. In this paper, a two-step TOA estimation algorithm is proposed for UWB systems in order to provide accurate TOA estimation under practical constraints. In order to speed up the estimation process, the first step estimates a coarse TOA of the received signal based on received signal energy. Then, in the second step, the arrival time of the first signal path is estimated by considering a hypothesis testing approach. The proposed scheme uses low-rate correlation outputs and is able to perform accurate TOA estimation in reasonable time intervals. The simulation results are presented to analyze the performance of the estimator.

The cc-bar and bb-bar spectroscopy in the two-step potential model

International Nuclear Information System (INIS)

Kulshreshtha, D.S.; Kaiserslautern Univ.

1984-07-01

We investigate the spectroscopy of the charmonium (cc-bar) and bottonium (bb-bar) bound states in a static flavour independent nonrelativistic quark-antiquark (qq-bar) two-step potential model proposed earlier. Our predictions are in good agreement with experimental data and with other theoretical predictions. (author)

A novel two-step method for screening shade tolerant mutant plants via dwarfism

Science.gov (United States)

When subjected to shade, plants undergo rapid shoot elongation, which often makes them more prone to disease and mechanical damage. It has been reported that, in turfgrass, induced dwarfism can enhance shade tolerance. Here, we describe a two-step procedure for isolating shade tolerant mutants of ...

Video-Recorded Validation of Wearable Step Counters under Free-living Conditions.

Science.gov (United States)

Toth, Lindsay P; Park, Susan; Springer, Cary M; Feyerabend, McKenzie D; Steeves, Jeremy A; Bassett, David R

2018-06-01

The purpose of this study was to determine the accuracy of 14-step counting methods under free-living conditions. Twelve adults (mean ± SD age, 35 ± 13 yr) wore a chest harness that held a GoPro camera pointed down at the feet during all waking hours for 1 d. The GoPro continuously recorded video of all steps taken throughout the day. Simultaneously, participants wore two StepWatch (SW) devices on each ankle (all programmed with different settings), one activPAL on each thigh, four devices at the waist (Fitbit Zip, Yamax Digi-Walker SW-200, New Lifestyles NL-2000, and ActiGraph GT9X (AG)), and two devices on the dominant and nondominant wrists (Fitbit Charge and AG). The GoPro videos were downloaded to a computer and researchers counted steps using a hand tally device, which served as the criterion method. The SW devices recorded between 95.3% and 102.8% of actual steps taken throughout the day (P > 0.05). Eleven step counting methods estimated less than 100% of actual steps; Fitbit Zip, Yamax Digi-Walker SW-200, and AG with the moving average vector magnitude algorithm on both wrists recorded 71% to 91% of steps (P > 0.05), whereas the activPAL, New Lifestyles NL-2000, and AG (without low-frequency extension (no-LFE), moving average vector magnitude) worn on the hip, and Fitbit Charge recorded 69% to 84% of steps (P 0.05), whereas the AG (LFE) on both wrists and the hip recorded 128% to 220% of steps (P < 0.05). Across all waking hours of 1 d, step counts differ between devices. The SW, regardless of settings, was the most accurate method of counting steps.

Improving the two-step remediation process for CCA-treated wood. Part I, Evaluating oxalic acid extraction

Science.gov (United States)

Carol Clausen

2004-01-01

In this study, three possible improvements to a remediation process for chromated-copper-arsenate (CCA) treated wood were evaluated. The process involves two steps: oxalic acid extraction of wood fiber followed by bacterial culture with Bacillus licheniformis CC01. The three potential improvements to the oxalic acid extraction step were (1) reusing oxalic acid for...

Two-step preparation of nano-scaled magnetic chitosan particles using Triton X-100 reversed-phase water-in-oil microemulsion system

Energy Technology Data Exchange (ETDEWEB)

Zhou, Zhengkun; Jiang, Feihong [College of Food Science and Engineering, Northwest A and F University, Yangling, Shaanxi 712100 (China); Lee, Tung-Ching, E-mail: lee@aesop.rutgers.edu [Department of Food Science, Rutgers, the State University of New Jersey, 65 Dudley Road, New Brunswick, NJ 08901 (United States); Yue, Tianli, E-mail: yuetl305@nwsuaf.edu.cn [College of Food Science and Engineering, Northwest A and F University, Yangling, Shaanxi 712100 (China)

2013-12-25

Highlights: •A new two-step route for nano-scaled magnetic chitosan particles preparation. •Triton X-100 reversed-phase microemulsion system was used for chitosan coating. •Narrow size distribution of magnetic chitosan nanoparticles was achieved. •Quantitative evaluation of recoverability for the magnetic chitosan nanoparticles. -- Abstract: A new two-step route for the preparation of nano-scaled magnetic chitosan particles has been developed, different from reported one-step in situ preparation and two-step preparation method of reversed-phase suspension, Triton X-100 reversed-phase water-in-oil microemulsion encapsulation method was employed in coating the pre-prepared Fe{sub 3}O{sub 4} nanoparticles with chitosan. The resultant magnetic chitosan particles owned a narrow size distribution ranging from 50 to 92 nm. X-ray diffraction patterns (XRD) indicated that the chitosan coating procedure did not change the spinal structure of Fe{sub 3}O{sub 4} magnetic nanoparticles. The results of Fourier transform infrared (FTIR) analysis and thermogravimetric analysis (TGA) demonstrated that the chitosan was coated on Fe{sub 3}O{sub 4} nanoparticles and its average mass content was ∼50%. The saturated magnetization of the magnetic Fe{sub 3}O{sub 4}/chitosan nanoparticles reached 18.62 emu/g, meanwhile, the nanoparticles showed the characteristics of superparamagnetism. The magnetic chitosan nanoparticles showed a high recoverability of 99.99% in 10 min when pH exceeded 4. The results suggested that the as-prepared magnetic chitosan particles were nano-scaled with a narrow size distribution and a high recoverability.

Finding First-Year Success in Extension: Navigating Stakeholders Needs and Institutional Expectations

Directory of Open Access Journals (Sweden)

Donald A. Llewellyn

2013-06-01

Full Text Available Functioning within a defined administrative framework and meeting the needs of the stakeholders are essential in an Extension appointment. The first day of employment starts the promotion and tenure clock. It is the responsibility of the new Extension professional to take immediate steps to move forward with development of programming and application of the skill set that they bring to the job. Finding success in the first year of an Extension appointment revolves around understanding the expectations of the institution and the needs of the stakeholders. Once the institutional expectations and programming needs are understood, formulating a strategy that includes plans of work and logic models, measurement of outcomes and impacts, team building, professional development, peer mentoring, grant writing, and scholarship will provide a foundation for first year success in Extension. A willingness to follow a timely and systematic approach to meeting the expectations of the institution and stakeholders will provide for an efficient transition and relieve many of the stressors associated with a new appointment. This paper is based primarily on the author’s first year experience as an Extension faculty member and summarizes several best practices.

A Two-Step Model for Assessing Relative Interest in E-Books Compared to Print

Science.gov (United States)

Knowlton, Steven A.

2016-01-01

Librarians often wish to know whether readers in a particular discipline favor e-books or print books. Because print circulation and e-book usage statistics are not directly comparable, it can be hard to determine the relative interest of readers in the two types of books. This study demonstrates a two-step method by which librarians can assess…

pH-Controlled Two-Step Uncoating of Influenza Virus

Science.gov (United States)

Li, Sai; Sieben, Christian; Ludwig, Kai; Höfer, Chris T.; Chiantia, Salvatore; Herrmann, Andreas; Eghiaian, Frederic; Schaap, Iwan A.T.

2014-01-01

Upon endocytosis in its cellular host, influenza A virus transits via early to late endosomes. To efficiently release its genome, the composite viral shell must undergo significant structural rearrangement, but the exact sequence of events leading to viral uncoating remains largely speculative. In addition, no change in viral structure has ever been identified at the level of early endosomes, raising a question about their role. We performed AFM indentation on single viruses in conjunction with cellular assays under conditions that mimicked gradual acidification from early to late endosomes. We found that the release of the influenza genome requires sequential exposure to the pH of both early and late endosomes, with each step corresponding to changes in the virus mechanical response. Step 1 (pH 7.5–6) involves a modification of both hemagglutinin and the viral lumen and is reversible, whereas Step 2 (pH pH step or blocking the envelope proton channel M2 precludes proper genome release and efficient infection, illustrating the importance of viral lumen acidification during the early endosomal residence for influenza virus infection. PMID:24703306

Dynamics Of Innovation Diffusion With Two Step Decision Process

Directory of Open Access Journals (Sweden)

Szymczyk Michał

2014-02-01

Full Text Available The paper discusses the dynamics of innovation diffusion among heterogeneous consumers. We assume that customers’ decision making process is divided into two steps: testing the innovation and later potential adopting. Such a model setup is designed to imitate the mobile applications market. An innovation provider, to some extent, can control the innovation diffusion by two parameters: product quality and marketing activity. Using the multi-agent approach we identify factors influencing the saturation level and the speed of innovation adaptation in the artificial population. The results show that the expected level of innovation adoption among customer’s friends and relative product quality and marketing campaign intensity are crucial factors explaining them. It has to be stressed that the product quality is more important for innovation saturation level and marketing campaign has bigger influence on the speed of diffusion. The topology of social network between customers is found important, but within investigated parameter range it has lover impact on innovation diffusion dynamics than the above mentioned factors

Overview of plant life extension technology development in Japan

International Nuclear Information System (INIS)

Takahashi, T.; Arai, H.; Akiyama, M.; Mishima, Y.; Okubo, T.

1993-01-01

In Japan, it is expected that the nuclear power will continue to play an important role in electric power supply. Since it is expected that the fast breeder reactor (FBR) will be introduced sometime during the first half of the 21st century, light water reactors (LWRs) will continue to play a key role some 30 to 40 years to come. For this reason, technology development projects are being implemented to further enhance light water reactor technology and thereby improve the reliability of LWRs. From this point, the Plant Life Extension (PLEX) technology development program [1-4] is entrusted by the Ministry of International Trade and Industry to the Japan Power Engineering and Inspection Corporation (JAPEIC). This program is an 11-year plan which started in 1985. The objectives are to extend the service lives of existing LWRs to increase the energy generated by these plants during their lifetime, and to reduce the lifetime generating costs. In this report, we will present our project overview and recent activities with respect to extensive verification tests on component material behavior. The JAPEIC PLEX project is divided into 3 phases. Phase I is the feasibility study. Phase 2 involves the verification tests and the evaluation of life extension technologies. The overall evaluation of the project will be conducted in Phase 3. The feasibility study of Phase I has been completed in fiscal year 1985 and 1986. In Phase I, the important components (the components and structures that are likely to govern the lives of nuclear power plants) have been selected. (author)

Fabrication of conductive copper patterns using reactive inkjet printing followed by two-step electroless plating

International Nuclear Information System (INIS)

Chen, Jin-Ju; Lin, Guo-Qiang; Wang, Yan; Sowade, Enrico; Baumann, Reinhard R.; Feng, Zhe-Sheng

2017-01-01

Highlights: • Copper patterns were fabricated by reactive inkjet printing and two-step electroless plating. • Cu particles produced via reactive inkjet printing act as catalyst for copper electroless plating. • High conductivity can be obtained without many printing passes and high temperature sintering. • This approach can largely avoid nozzle-clogging problems. • This approach presents a potential way in the flexible printed electronics with simple process. - Abstract: A simple and low-cost process for fabricating conductive copper patterns on flexible polyimide substrates was demonstrated. Copper catalyst patterns were first produced on polyimide substrates using reactive inkjet printing of Cu (II)-bearing ink and reducing ink, and then the conductive copper patterns were generated after a two-step electroless plating procedure. The copper layers were characterized by optical microscope, SEM, XRD and EDS. Homogeneously distributed copper nanoclusters were found in the catalyst patterns. A thin copper layer with uniform particle size was formed after first-step electroless plating, and a thick copper layer of about 14.3 μm with closely packed structure and fine crystallinity was produced after second-step electroless plating. This resulting copper layer had good solderability, reliable adhesion strength and a low resistivity of 5.68 μΩ cm without any sintering process.

Fabrication of conductive copper patterns using reactive inkjet printing followed by two-step electroless plating

Energy Technology Data Exchange (ETDEWEB)

Chen, Jin-Ju; Lin, Guo-Qiang; Wang, Yan [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Sowade, Enrico; Baumann, Reinhard R. [Digital Printing and Imaging Technology, Technische Universität Chemnitz, Chemnitz, 09126 (Germany); Feng, Zhe-Sheng, E-mail: fzs@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

2017-02-28

Highlights: • Copper patterns were fabricated by reactive inkjet printing and two-step electroless plating. • Cu particles produced via reactive inkjet printing act as catalyst for copper electroless plating. • High conductivity can be obtained without many printing passes and high temperature sintering. • This approach can largely avoid nozzle-clogging problems. • This approach presents a potential way in the flexible printed electronics with simple process. - Abstract: A simple and low-cost process for fabricating conductive copper patterns on flexible polyimide substrates was demonstrated. Copper catalyst patterns were first produced on polyimide substrates using reactive inkjet printing of Cu (II)-bearing ink and reducing ink, and then the conductive copper patterns were generated after a two-step electroless plating procedure. The copper layers were characterized by optical microscope, SEM, XRD and EDS. Homogeneously distributed copper nanoclusters were found in the catalyst patterns. A thin copper layer with uniform particle size was formed after first-step electroless plating, and a thick copper layer of about 14.3 μm with closely packed structure and fine crystallinity was produced after second-step electroless plating. This resulting copper layer had good solderability, reliable adhesion strength and a low resistivity of 5.68 μΩ cm without any sintering process.

A two-step acid-catalyzed process for the production of biodiesel from rice bran oil

Energy Technology Data Exchange (ETDEWEB)

Zullaikah, S.; Lai, Chao Chin; Vali, S.R.; Ju, Yi Hsu [National Taiwan Univ. of Science and Technology, Taipei (China). Dept. of Chemical Engineering

2005-11-15

A study was undertaken to examine the effect of temperature, moisture and storage time on the accumulation of free fatty acid in the rice bran. Rice bran stored at room temperature showed that most triacylglyceride was hydrolyzed and free fatty acid (FFA) content was raised up to 76% in six months. A two-step acid-catalyzed methanolysis process was employed for the efficient conversion of rice bran oil into fatty acid methyl ester (FAME). The first step was carried out at 60 {sup o}C. Depending on the initial FFA content of oil, 55-90% FAME content in the reaction product was obtained. More than 98% FFA and less than 35% of TG were reacted in 2 h. The organic phase of the first step reaction product was used as the substrate for a second acid-catalyzed methanolysis at 100 {sup o}C. By this two-step methanolysis reaction, more than 98% FAME in the product can be obtained in less than 8 h. Distillation of reaction product gave 99.8% FAME (biodiesel) with recovery of more than 96%. The residue contains enriched nutraceuticals such as {gamma}-oryzanol (16-18%), mixture of phytosterol, tocol and steryl ester (19-21%). (author)

Four-year clinical evaluation of Class II nano-hybrid resin composite restorations bonded with a one-step self-etch and a two-step etch-and-rinse adhesive

DEFF Research Database (Denmark)

van Dijken, Jan W V; Pallesen, Ulla

2011-01-01

The objective of this prospective clinical trial was to evaluate the 4-year clinical performance of an ormocer-based nano-hybrid resin composite (Ceram X; Dentsply/DeTrey) in Class II restorations placed with a one-step self-etch (Xeno III; Dentsply/DeTrey) and two-step etch-and-rinse adhesive (I...

Spectrum analysis of the reduction degree of two-step reduced graphene oxide (GO) and the polymer/r-GO composites

Energy Technology Data Exchange (ETDEWEB)

She, Xilin, E-mail: xlshe@qdu.edu.cn [College of Chemical and Environmental Engineering, Qingdao University, Qingdao 266071 (China); Liu, Tongchao; Wu, Nan [College of Chemical and Environmental Engineering, Qingdao University, Qingdao 266071 (China); Xu, Xijin [School of Physics and Technology, University of Jinan, Jinan 250022 (China); Li, Jianjiang [College of Chemical and Environmental Engineering, Qingdao University, Qingdao 266071 (China); Yang, Dongjiang, E-mail: d.yang@qdu.edu.cn [College of Chemical and Environmental Engineering, Qingdao University, Qingdao 266071 (China); School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray [School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

2013-12-16

In this paper, the reduction degree of graphene oxide (GO) reduced using chemical reduction and thermal reduction methods was characterized by spectrum analysis. The optimized conditions of reducing GO were determined that the hydrazine hydrate is the best reducing agent and the appropriate thermal reduction temperature is at 240 °C. The obtained GO solution was mixed with polystyrene (PS) solution to prepare PS/r-GO composites by using two-step reduction technique under the optimized conditions. The structure and micro-morphology of GO, r-GO and PS/r-GO composites were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) respectively. It is also observed that the two-step reduction pathway is more effective than one-step reduction for improving the reduction degree of GO. Accordingly, the electric conductivity of PS/r-GO composites prepared by two-step reduction technique is as high as 21.45 S m{sup −1}, which is much higher than that of composites fabricated by one-step reduction method. The spectrum techniques will highlight new opportunities for investigating the reduction degree of GO in polymer composites. - Highlights: • Spectrum analysis on the reduction degree of GO reduced by different methods. • Determine the optimized reduction conditions of GO and polymer/r-GO composites. • The two-step reduction is more effective than one-step reduction.

Spectrum analysis of the reduction degree of two-step reduced graphene oxide (GO) and the polymer/r-GO composites

International Nuclear Information System (INIS)

She, Xilin; Liu, Tongchao; Wu, Nan; Xu, Xijin; Li, Jianjiang; Yang, Dongjiang; Frost, Ray

2013-01-01

In this paper, the reduction degree of graphene oxide (GO) reduced using chemical reduction and thermal reduction methods was characterized by spectrum analysis. The optimized conditions of reducing GO were determined that the hydrazine hydrate is the best reducing agent and the appropriate thermal reduction temperature is at 240 °C. The obtained GO solution was mixed with polystyrene (PS) solution to prepare PS/r-GO composites by using two-step reduction technique under the optimized conditions. The structure and micro-morphology of GO, r-GO and PS/r-GO composites were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) respectively. It is also observed that the two-step reduction pathway is more effective than one-step reduction for improving the reduction degree of GO. Accordingly, the electric conductivity of PS/r-GO composites prepared by two-step reduction technique is as high as 21.45 S m −1 , which is much higher than that of composites fabricated by one-step reduction method. The spectrum techniques will highlight new opportunities for investigating the reduction degree of GO in polymer composites. - Highlights: • Spectrum analysis on the reduction degree of GO reduced by different methods. • Determine the optimized reduction conditions of GO and polymer/r-GO composites. • The two-step reduction is more effective than one-step reduction

Step growth of two flexible ABf monomers

DEFF Research Database (Denmark)

Cameron, Colin; Fawcett, Allan H.; Hetherington, Cecil R.

2000-01-01

A three-dimensional lattice model was used to simulate the competition between the growth of hyperbranched structures and cycle formation that occurs when flexible ABf monomers undergo step growth. The monomers in the model are mapped onto several lattice sites. The effect of functionality...

Developing novel extensions to support prototyping for interactive social robots

NARCIS (Netherlands)

Bhömer, ten M.; Bartneck, C.; Hu, J.; Ahn, R.M.C.; Tuyls, K.P.; Delbressine, F.L.M.; Feijs, L.M.G.

2009-01-01

Lego Mindstorms NXT is a platform highly suitable for prototyping in the field of interactive social robotics. During a technology masterclass at Eindhoven University of Technology students from the department of Industrial Design have developed five novel extensions (sensors and actuators) for the

Game Theory and Technical Communication: Interpreting the Texas Two-Step through Harsanyi Transformation

Science.gov (United States)

Williams, Miriam F.

2012-01-01

The author uses game theoretical models to identify technical communication breakdowns encountered during the notoriously confusing Texas Two-Step voting and caucusing process. Specifically, the author uses narrative theory and game theory to highlight areas where caucus participants needed instructions to better understand the rules of the game…

Supersymmetric extensions of K field theories

Science.gov (United States)

Adam, C.; Queiruga, J. M.; Sanchez-Guillen, J.; Wereszczynski, A.

2012-02-01

We review the recently developed supersymmetric extensions of field theories with non-standard kinetic terms (so-called K field theories) in two an three dimensions. Further, we study the issue of topological defect formation in these supersymmetric theories. Specifically, we find supersymmetric K field theories which support topological kinks in 1+1 dimensions as well as supersymmetric extensions of the baby Skyrme model for arbitrary nonnegative potentials in 2+1 dimensions.

Recovery of forward stepping in spinal cord injured patients does not transfer to untrained backward stepping.

Science.gov (United States)

Grasso, Renato; Ivanenko, Yuri P; Zago, Myrka; Molinari, Marco; Scivoletto, Giorgio; Lacquaniti, Francesco

2004-08-01

Six spinal cord injured (SCI) patients were trained to step on a treadmill with body-weight support for 1.5-3 months. At the end of training, foot motion recovered the shape and the step-by-step reproducibility that characterize normal gait. They were then asked to step backward on the treadmill belt that moved in the opposite direction relative to standard forward training. In contrast to healthy subjects, who can immediately reverse the direction of walking by time-reversing the kinematic waveforms, patients were unable to step backward. Similarly patients were unable to perform another untrained locomotor task, namely stepping in place on the idle treadmill. Two patients who were trained to step backward for 2-3 weeks were able to develop control of foot motion appropriate for this task. The results show that locomotor improvement does not transfer to untrained tasks, thus supporting the idea of task-dependent plasticity in human locomotor networks.

Cloning-free template DNA preparation for cell-free protein synthesis via two-step PCR using versatile primer designs with short 3'-UTR.

Science.gov (United States)

Nomoto, Mika; Tada, Yasuomi

2018-01-01

Cell-free protein synthesis (CFPS) systems largely retain the endogenous translation machinery of the host organism, making them highly applicable for proteomics analysis of diverse biological processes. However, laborious and time-consuming cloning procedures hinder progress with CFPS systems. Herein, we report the development of a rapid and efficient two-step polymerase chain reaction (PCR) method to prepare linear DNA templates for a wheat germ CFPS system. We developed a novel, effective short 3'-untranslated region (3'-UTR) sequence that facilitates translation. Application of the short 3'-UTR to two-step PCR enabled the generation of various transcription templates from the same plasmid, including fusion proteins with N- or C-terminal tags, and truncated proteins. Our method supports the cloning-free expression of target proteins using an mRNA pool from biological material. The established system is a highly versatile platform for in vitro protein synthesis using wheat germ CFPS. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Low temperature synthesis of nano alpha-alumina powder by two-step hydrolysis

International Nuclear Information System (INIS)

Yan, Ting; Guo, Xiaode; Zhang, Xiang; Wang, Zhixiang; Shi, Jinqiu

2016-01-01

Highlights: • The nano α-Al 2 O 3 with good dispersion was prepared by two-step hydrolysis. • α-Al 2 O 3 powders were added as seed particles in the hydrolysis. • This article indicated that the glucose could impel the γ-Al 2 O 3 transformed to α-Al 2 O 3 directly. • This article indicated that the addictive of α-Al 2 O 3 seed could improve the phase transformation rate of γ-Al 2 O 3 to α-Al 2 O 3 . • In this article, the pure α-Al 2 O 3 could be obtained by calcining at 1000 °C for 1.5 h. - Abstract: The ultral fine alpha-alumina powder has been successfully synthesized via two-step hydrolysis of aluminum isopropoxide. Glucose and polyvinyl pyrrolidone were used as surfactants during the appropriate processing step. The alpha-alumina powder was used as seed particles. Several synthesis parameters, such as the amount of seeds, surfactants, and calcination temperature, were studied by X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), Thermogravimetry-differential scanning calorimetry (TG-DSC), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results showed that glucose greatly lower the phase transformation temperature of alpha-alumina by impelling the gamma-alumina transformed to alpha-alumina directly, and the seed could improve the phase transformation rate of alpha-alumina, the polyvinylpyrrolidone have an effect on preventing excessive grain growth and agglomeration of alpha-alumina powder. Comparatively well dispersed alpha-alumina powder with particle size less than 50 nm can be synthesized through this method after calcinations at 1000 °C for 2 h.

DEVELOPMENT OF HOLE RECOGNITION SYSTEM FROM STEP FILE

Directory of Open Access Journals (Sweden)

C. F. Tan

2017-11-01

Full Text Available This paper describes the development of Hole Recognition System (HRS for Computer-Aided Process Planning (CAPP using a neutral data format produced by CAD system. The geometrical data of holes is retrieved from STandard for the Exchange of Product model data (STEP. Rule-based algorithm is used during recognising process. Current implementation of feature recognition is limited to simple hole feat ures. Test results are presented to demonstrate the capabilities of the feature recognition algorithm.

Defining Audience Segments for Extension Programming Using Reported Water Conservation Practices

Science.gov (United States)

Monaghan, Paul; Ott, Emily; Wilber, Wendy; Gouldthorpe, Jessica; Racevskis, Laila

2013-01-01

A tool from social marketing can help Extension agents understand distinct audience segments among their constituents. Defining targeted audiences for Extension programming is a first step to influencing behavior change among the public. An online survey was conducted using an Extension email list for urban households receiving a monthly lawn and…

Kalman Filtering for Discrete Stochastic Systems with Multiplicative Noises and Random Two-Step Sensor Delays

Directory of Open Access Journals (Sweden)

Dongyan Chen

2015-01-01

Full Text Available This paper is concerned with the optimal Kalman filtering problem for a class of discrete stochastic systems with multiplicative noises and random two-step sensor delays. Three Bernoulli distributed random variables with known conditional probabilities are introduced to characterize the phenomena of the random two-step sensor delays which may happen during the data transmission. By using the state augmentation approach and innovation analysis technique, an optimal Kalman filter is constructed for the augmented system in the sense of the minimum mean square error (MMSE. Subsequently, the optimal Kalman filtering is derived for corresponding augmented system in initial instants. Finally, a simulation example is provided to demonstrate the feasibility and effectiveness of the proposed filtering method.

A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters

DEFF Research Database (Denmark)

Hovgård, Holger

1996-01-01

by normal distributions and could be related to mesh size in accordance with the principle of geometrical similarity. In the second step the selection parameters were estimated by a nonlinear least squares fit. The model also estimated the relative efficiency of the two capture processes and the fishing......Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described...

One step forward, two steps back? The GMC, the common law and 'informed' consent.

Science.gov (United States)

Fovargue, Sara; Miola, José

2010-08-01

Until 2008, if doctors followed the General Medical Council's (GMC's) guidance on providing information prior to obtaining a patient's consent to treatment, they would be going beyond what was technically required by the law. It was hoped that the common law would catch up with this guidance and encourage respect for patients' autonomy by facilitating informed decision-making. Regrettably, this has not occurred. For once, the law's inability to keep up with changing medical practice and standards is not the problem. The authors argue that while the common law has moved forward and started to recognise the importance of patient autonomy and informed decision-making, the GMC has taken a step back in their 2008 guidance on consent. Indeed, doctors are now required to tell their patients less than they were in 1998 when the last guidance was produced. This is an unfortunate development and the authors urge the GMC to revisit their guidance.

Simple Plans or Sophisticated Habits? State, Transition and Learning Interactions in the Two-Step Task.

Directory of Open Access Journals (Sweden)

Thomas Akam

2015-12-01

Full Text Available The recently developed 'two-step' behavioural task promises to differentiate model-based from model-free reinforcement learning, while generating neurophysiologically-friendly decision datasets with parametric variation of decision variables. These desirable features have prompted its widespread adoption. Here, we analyse the interactions between a range of different strategies and the structure of transitions and outcomes in order to examine constraints on what can be learned from behavioural performance. The task involves a trade-off between the need for stochasticity, to allow strategies to be discriminated, and a need for determinism, so that it is worth subjects' investment of effort to exploit the contingencies optimally. We show through simulation that under certain conditions model-free strategies can masquerade as being model-based. We first show that seemingly innocuous modifications to the task structure can induce correlations between action values at the start of the trial and the subsequent trial events in such a way that analysis based on comparing successive trials can lead to erroneous conclusions. We confirm the power of a suggested correction to the analysis that can alleviate this problem. We then consider model-free reinforcement learning strategies that exploit correlations between where rewards are obtained and which actions have high expected value. These generate behaviour that appears model-based under these, and also more sophisticated, analyses. Exploiting the full potential of the two-step task as a tool for behavioural neuroscience requires an understanding of these issues.

Simple Plans or Sophisticated Habits? State, Transition and Learning Interactions in the Two-Step Task.

Science.gov (United States)

Akam, Thomas; Costa, Rui; Dayan, Peter

2015-12-01

The recently developed 'two-step' behavioural task promises to differentiate model-based from model-free reinforcement learning, while generating neurophysiologically-friendly decision datasets with parametric variation of decision variables. These desirable features have prompted its widespread adoption. Here, we analyse the interactions between a range of different strategies and the structure of transitions and outcomes in order to examine constraints on what can be learned from behavioural performance. The task involves a trade-off between the need for stochasticity, to allow strategies to be discriminated, and a need for determinism, so that it is worth subjects' investment of effort to exploit the contingencies optimally. We show through simulation that under certain conditions model-free strategies can masquerade as being model-based. We first show that seemingly innocuous modifications to the task structure can induce correlations between action values at the start of the trial and the subsequent trial events in such a way that analysis based on comparing successive trials can lead to erroneous conclusions. We confirm the power of a suggested correction to the analysis that can alleviate this problem. We then consider model-free reinforcement learning strategies that exploit correlations between where rewards are obtained and which actions have high expected value. These generate behaviour that appears model-based under these, and also more sophisticated, analyses. Exploiting the full potential of the two-step task as a tool for behavioural neuroscience requires an understanding of these issues.

Two-step Purification Method for Aging Pigments A2E and Iso-A2E Using Medium Pressure Liquid Chromatography

International Nuclear Information System (INIS)

Park, Sang Il; Park, Sang Cheol; Kim, So Ra; Jang, Young Pyo

2016-01-01

A newly modified method for the efficient purification of A2E and iso-A2E using reverse phase silica gel resin with medium pressure liquid chromatography (MPLC) was suggested. MPLC is one of the various preparative column chromatography techniques and separation under pressure renders the use of smaller particle size resins possible and increases the diversity of available stationary phases. A simplified two-step purification method was developed for the purification of aging pigments in eye, A2E and iso-A2E. With simple two-step elution of mobile phase in reverse phase MPLC, A2E and iso-A2E were successfully purified with great efficiency compare with previous column chromatography and HPLC method. This method provides more simple, convenient, cost-effective, and less time-consuming procedure for mass purification of aging pigments A2E and iso-A2E

Two-step Purification Method for Aging Pigments A2E and Iso-A2E Using Medium Pressure Liquid Chromatography

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Il; Park, Sang Cheol [Kyunghee Univ., Seoul (Korea, Republic of); Kim, So Ra; Jang, Young Pyo [Seoul National Univ., Seoul (Korea, Republic of)

2016-09-15

A newly modified method for the efficient purification of A2E and iso-A2E using reverse phase silica gel resin with medium pressure liquid chromatography (MPLC) was suggested. MPLC is one of the various preparative column chromatography techniques and separation under pressure renders the use of smaller particle size resins possible and increases the diversity of available stationary phases. A simplified two-step purification method was developed for the purification of aging pigments in eye, A2E and iso-A2E. With simple two-step elution of mobile phase in reverse phase MPLC, A2E and iso-A2E were successfully purified with great efficiency compare with previous column chromatography and HPLC method. This method provides more simple, convenient, cost-effective, and less time-consuming procedure for mass purification of aging pigments A2E and iso-A2E.

Analyzing angular distributions for two-step dissociation mechanisms in velocity map imaging.

Science.gov (United States)

Straus, Daniel B; Butler, Lynne M; Alligood, Bridget W; Butler, Laurie J

2013-08-15

Increasingly, velocity map imaging is becoming the method of choice to study photoinduced molecular dissociation processes. This paper introduces an algorithm to analyze the measured net speed, P(vnet), and angular, β(vnet), distributions of the products from a two-step dissociation mechanism, where the first step but not the second is induced by absorption of linearly polarized laser light. Typically, this might be the photodissociation of a C-X bond (X = halogen or other atom) to produce an atom and a momentum-matched radical that has enough internal energy to subsequently dissociate (without the absorption of an additional photon). It is this second step, the dissociation of the unstable radicals, that one wishes to study, but the measured net velocity of the final products is the vector sum of the velocity imparted to the radical in the primary photodissociation (which is determined by taking data on the momentum-matched atomic cophotofragment) and the additional velocity vector imparted in the subsequent dissociation of the unstable radical. The algorithm allows one to determine, from the forward-convolution fitting of the net velocity distribution, the distribution of velocity vectors imparted in the second step of the mechanism. One can thus deduce the secondary velocity distribution, characterized by a speed distribution P(v1,2°) and an angular distribution I(θ2°), where θ2° is the angle between the dissociating radical's velocity vector and the additional velocity vector imparted to the product detected from the subsequent dissociation of the radical.

Factors affecting job satisfaction of front-line extension workers in ...

African Journals Online (AJOL)

The study examined the factors affecting job satisfaction of field extension workers in Enugu State Agricultural Development Programme. Forty-two extension staff randomly selected across the three agricultural zones were used for the study. The field extension workers indicated low level of satisfaction with their job content, ...

SYSTEMATIZATION OF THE BASIC STEPS OF THE STEP-AEROBICS

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Darinka Korovljev

2011-03-01

Full Text Available Following the development of the powerful sport industry, in front of us appeared a lot of new opportunities for creating of the new programmes of exercising with certain requisites. One of such programmes is certainly step-aerobics. Step-aerobics can be defined as a type of aerobics consisting of the basic aerobic steps (basic steps applied in exercising on stepper (step bench, with a possibility to regulate its height. Step-aerobics itself can be divided into several groups, depending on the following: type of music, working methods and adopted knowledge of the attendants. In this work, the systematization of the basic steps in step-aerobics was made on the basis of the following criteria: steps origin, number of leg motions in stepping and relating the body support at the end of the step. Systematization of the basic steps of the step-aerobics is quite significant for making a concrete review of the existing basic steps, thus making creation of the step-aerobics lesson easier

Two-step versus one-step FT4 assays in heparin treated patients and non-thyroidal illness

International Nuclear Information System (INIS)

Reiners, C.; Bieler, G.; Ertl, G.; Gloss, H.; Boerner, W.

1985-01-01

The primary intention of this study is to inform the clinician about the direction and the order of magnitude of possible disturbances of different FT 4 parameters under the condition mentioned last, which is not uncommon in daily routine. No single FT 4 -RIA proved be valid in severe NTI. There is the risk to misinterprete hyperthyroidism as euthyroidism with 1step assays and the possibility to classify euthyroid patients falsely as hyperthyroid with 2step assays. In relation to this problem, the sometimes lowered FT 4 values by 1step methods are clinically not so important. It has to be established, wether TSH assays of high sensitivity are able to overcome some of the difficulties with determinations of peripheral thyroid hormones in NTI. (orig./MG)

On the limitations of fixed-step-size adaptive methods with response confidence.

Science.gov (United States)

Hsu, Yung-Fong; Chin, Ching-Lan

2014-05-01

The family of (non-parametric, fixed-step-size) adaptive methods, also known as 'up-down' or 'staircase' methods, has been used extensively in psychophysical studies for threshold estimation. Extensions of adaptive methods to non-binary responses have also been proposed. An example is the three-category weighted up-down (WUD) method (Kaernbach, 2001) and its four-category extension (Klein, 2001). Such an extension, however, is somewhat restricted, and in this paper we discuss its limitations. To facilitate the discussion, we characterize the extension of WUD by an algorithm that incorporates response confidence into a family of adaptive methods. This algorithm can also be applied to two other adaptive methods, namely Derman's up-down method and the biased-coin design, which are suitable for estimating any threshold quantiles. We then discuss via simulations of the above three methods the limitations of the algorithm. To illustrate, we conduct a small scale of experiment using the extended WUD under different response confidence formats to evaluate the consistency of threshold estimation. © 2013 The British Psychological Society.

Comparison of enamel bond fatigue durability of universal adhesives and two-step self-etch adhesives in self-etch mode.

Science.gov (United States)

Tsujimoto, Akimasa; Barkmeier, Wayne W; Hosoya, Yumiko; Nojiri, Kie; Nagura, Yuko; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

2017-10-01

To comparatively evaluate universal adhesives and two-step self-etch adhesives for enamel bond fatigue durability in self-etch mode. Three universal adhesives (Clearfil Universal Bond; G-Premio Bond; Scotchbond Universal Adhesive) and three two-step self-etch adhesives (Clearfil SE Bond; Clearfil SE Bond 2; OptiBond XTR) were used. The initial shear bond strength and shear fatigue strength of the adhesive to enamel in self-etch mode were determined. The initial shear bond strengths of the universal adhesives to enamel in self-etch mode was significantly lower than those of two-step self-etch adhesives and initial shear bond strengths were not influenced by type of adhesive in each adhesive category. The shear fatigue strengths of universal adhesives to enamel in self-etch mode were significantly lower than that of Clearfil SE Bond and Clearfil SE Bond 2, but similar to that OptiBond XTR. Unlike two-step self-etch adhesives, the initial shear bond strength and shear fatigue strength of universal adhesives to enamel in self-etch mode was not influenced by the type of adhesive. This laboratory study showed that the enamel bond fatigue durability of universal adhesives was lower than Clearfil SE Bond and Clearfil SE Bond 2, similar to Optibond XTR, and was not influenced by type of adhesive, unlike two-step self-etch adhesives.

R.f.-induced steps in mutually coupled, two-dimensional distributed Josephson tunnel junctions

International Nuclear Information System (INIS)

Klein, U.; Dammschneider, P.

1991-01-01

This paper reports on the amplitudes of the current steps in the I-V characteristics of mutually coupled two-dimensional distributed Josephson tunnel junctions driven by microwaves. For this purpose we use a numerical computation algorithm based on a planar resonator model for the individual Josephson tunnel junctions to calculate the d.c. current density distribution. In addition to the fundamental microwave frequency, harmonic contents of the tunneling current are also considered. The lateral dimensions of the individual junctions are small compared to the microwave wavelength and the Josephson penetration depth, giving an almost constant current density distribution. Therefore, the coupled junctions can give much greater step amplitudes than a single junction with an equal tunneling area, because of their nonuniform current density distribution

Interpenetrating networks of two conducting polymers

DEFF Research Database (Denmark)

Winther-Jensen, Bjørn; West, Keld

2005-01-01

Interpenetrating networks (IPNs) of two conjugated polymers are prepared by a combination of a chemical oxidation step and a vapour phase polymerisation step on non-conducting surfaces. In this work ferric tosylate was used as the oxidant as it gives very smooth and homogeneous coatings, and beca......Interpenetrating networks (IPNs) of two conjugated polymers are prepared by a combination of a chemical oxidation step and a vapour phase polymerisation step on non-conducting surfaces. In this work ferric tosylate was used as the oxidant as it gives very smooth and homogeneous coatings......, and because its reaction products can be removed efficiently after the formation of the composite. Several combinations of polymers are demonstrated, and the versatility of the proposed method allows extensions to a wide range of conjugated polymers. The IPNs show optical and electrochemical characteristics......, which are sums of the characteristics from the participating conducting polymers....

Standardization of a two-step real-time polymerase chain reaction based method for species-specific detection of medically important Aspergillus species.

Science.gov (United States)

Das, P; Pandey, P; Harishankar, A; Chandy, M; Bhattacharya, S; Chakrabarti, A

2017-01-01

Standardization of Aspergillus polymerase chain reaction (PCR) poses two technical challenges (a) standardization of DNA extraction, (b) optimization of PCR against various medically important Aspergillus species. Many cases of aspergillosis go undiagnosed because of relative insensitivity of conventional diagnostic methods such as microscopy, culture or antigen detection. The present study is an attempt to standardize real-time PCR assay for rapid sensitive and specific detection of Aspergillus DNA in EDTA whole blood. Three nucleic acid extraction protocols were compared and a two-step real-time PCR assay was developed and validated following the recommendations of the European Aspergillus PCR Initiative in our setup. In the first PCR step (pan-Aspergillus PCR), the target was 28S rDNA gene, whereas in the second step, species specific PCR the targets were beta-tubulin (for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus), gene and calmodulin gene (for Aspergillus niger). Species specific identification of four medically important Aspergillus species, namely, A. fumigatus, A. flavus, A. niger and A. terreus were achieved by this PCR. Specificity of the PCR was tested against 34 different DNA source including bacteria, virus, yeast, other Aspergillus sp., other fungal species and for human DNA and had no false-positive reactions. The analytical sensitivity of the PCR was found to be 102 CFU/ml. The present protocol of two-step real-time PCR assays for genus- and species-specific identification for commonly isolated species in whole blood for diagnosis of invasive Aspergillus infections offers a rapid, sensitive and specific assay option and requires clinical validation at multiple centers.

Enhanced age-strengthening by two-step progressive solution treatment in an Mg–Zn–Al–Re alloy

International Nuclear Information System (INIS)

Zhang, Jing; Yuan, Fuqing; Du, Yong

2013-01-01

Highlights: • A two-step progressive solution treatment schedule was proposed. • The treatment enhanced dissolution of ternary eutectic phases in Mg–Zn–Al alloy. • Solution temperature could break the limit of the ternary eutectic temperature. • There was no microstructural over-heating defect during the progressive heating. • The τ precipitates have a remarkable dispersion strengthening effect. - Abstract: A two-step progressive solution treatment was designed and performed on an as-extruded Mg–7Zn–3Al–0.7Er alloy. The resultant microstructure and mechanical properties were examined by means of scanning electron microscopy, X-ray diffractometer, differential scanning calorimetry and hardness testing. The results showed that the two-step progressive solution treatment could enhance the dissolution of the ternary eutectic phases in the Mg–Zn–Al system without the formation of microstructure over-heating defects. After homogenization for 50 h at 325 °C, the volume fraction of the undissolved particles in the Mg–7Zn–3Al–0.7Er alloy ingot was ∼4.1%. Two-step progressive solution treatment performed on the as-extruded alloy could further dissolve the particles. Only 1.5% undissolved particles remained after the treatment. The supersaturated degree of both the dissolved solute atoms and vacancies in the α-Mg matrix was expected to be increased, resulting in an enhanced age-strengthening, compared with normal solution and aging treatments. Moreover, the processed alloy exhibited a homogenous and stable fine grain structure. Remarkable dispersion strengthening effect of ternary τ (Mg 32 (Al,Zn) 49 ) precipitates occurred in Mg–Zn–Al alloy was also identified

The ‘SAR Matrix’ method and its extensions for applications in medicinal chemistry and chemogenomics [v1; ref status: indexed, http://f1000r.es/3gh

Directory of Open Access Journals (Sweden)

Disha Gupta-Ostermann

2014-05-01

Full Text Available We describe the ‘Structure-Activity Relationship (SAR Matrix’ (SARM methodology that is based upon a special two-step application of the matched molecular pair (MMP formalism. The SARM method has originally been designed for the extraction, organization, and visualization of compound series and associated SAR information from compound data sets. It has been further developed and adapted for other applications including compound design, activity prediction, library extension, and the navigation of multi-target activity spaces. The SARM approach and its extensions are presented here in context to introduce different types of applications and provide an example for the evolution of a computational methodology in pharmaceutical research.

The ‘SAR Matrix’ method and its extensions for applications in medicinal chemistry and chemogenomics [v2; ref status: indexed, http://f1000r.es/3rg

Directory of Open Access Journals (Sweden)

Disha Gupta-Ostermann

2014-06-01

Full Text Available We describe the ‘Structure-Activity Relationship (SAR Matrix’ (SARM methodology that is based upon a special two-step application of the matched molecular pair (MMP formalism. The SARM method has originally been designed for the extraction, organization, and visualization of compound series and associated SAR information from compound data sets. It has been further developed and adapted for other applications including compound design, activity prediction, library extension, and the navigation of multi-target activity spaces. The SARM approach and its extensions are presented here in context to introduce different types of applications and provide an example for the evolution of a computational methodology in pharmaceutical research.

Two-step deposition of Al-doped ZnO on p-GaN to form ohmic contacts

Science.gov (United States)

Su, Xi; Zhang, Guozhen; Wang, Xiao; Chen, Chao; Wu, Hao; Liu, Chang

2017-07-01

Al-doped ZnO (AZO) thin films were deposited directly on p-GaN substrates by using a two-step deposition consisting of polymer assisted deposition (PAD) and atomic layer deposition (ALD) methods. Ohmic contacts of the AZO on p-GaN have been formed. The lowest sheet resistance of the two-step prepared AZO films reached to 145 Ω/sq, and the specific contact resistance reduced to 1.47 × 10-2 Ω·cm2. Transmittance of the AZO films remained above 80% in the visible region. The combination of PAD and ALD technique can be used to prepare p-type ohmic contacts for optoelectronics.

THE DEVELOPMENT OF AIR-THEME INTEGRATED SCIENCE TEACHING MATERIAL USING FOUR STEPS TEACHING MATERIAL DEVELOPMENT

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A. Arifin

2016-01-01

Full Text Available The purposes of this study are to develop, to test the feasibility, to describe the characteristic, and to test the students understanding about integrated science teaching material about air using Four Steps Teaching Material Development (4S TMD. The Research and Development method was use to develop integrated science teaching materials which is involving  all science perspectives that are not presented in junior high school science book. The air theme was chosen in this study since it can be explained using biology, chemistry, physics, and earth and space science  perspectives. Development the teaching materials was consists of selection, structuring, characterization, and reduction didactic steps. Based on the of feasibility test results, the teaching material is qualified in content, presentation, language, and graphic feasibility aspects. The characteristic of this teaching material expose the closeness theme with student daily lifes and its compatibility with National Books Standard. Based on the understanding test results, the teaching material is qualified in understanding aspect with high category. It can be concluded that the teaching material qualified to be used as supplement teaching material of science learning.Penelitian ini bertujuan untuk mengembangkan, menguji kelayakan, memaparkan karakteristik, dan menguji keterpahaman bahan ajar IPA terpadu pada tema udara untuk siswa SMP kelas VII melalui Four Steps Teaching Material Development (4S TMD. Penelitian dengan metode Research and Development (R&D ini dilatar belakangi oleh tidak tersedianya bahan ajar IPA SMP yang disajikan secara terpadu melalui tema udara. Pengembangan bahan ajar IPA terpadu tema udara terdiri dari tahap seleksi, strukturisasi, karakterisasi dan reduksi didaktik. Berdasarkan uji kelayakan, bahan ajar telah memenuhi aspek kelayakan isi, kelayakan penyajian, kelayakan bahasa dan kelayakan kegrafikan. Karakteristik bahan ajar meliputi kedekatan tema bahan ajar

Two Step Procedure Using a 1-D Slab Spectral Geometry in a Pebble Bed Reactor Core Analysis

International Nuclear Information System (INIS)

Lee, Hyun Chul; Kim, Kang Seog; Noh, Jae Man; Joo, Hyung Kook

2005-01-01

A strong spectral interaction between the core and the reflector has been one of the main concerns in the analysis of pebble bed reactor cores. To resolve this problem, VSOP adopted iteration between the spectrum calculation in a spectral zone and the global core calculation. In VSOP, the whole problem domain is divided into many spectral zones in which the fine group spectrum is calculated using bucklings for fast groups and albedos for thermal groups from the global core calculation. The resulting spectrum in each spectral zone is used to generate broad group cross sections of the spectral zone for the global core calculation. In this paper, we demonstrate a two step procedure in a pebble bed reactor core analysis. In the first step, we generate equivalent cross sections from a 1-D slab spectral geometry model with the help of the equivalence theory. The equivalent cross sections generated in this way include the effect of the spectral interaction between the core and the reflector. In the second step, we perform a diffusion calculation using the equivalent cross sections generated in the first step. A simple benchmark problem derived from the PMBR-400 Reactor was introduced to verify this approach. We compared the two step solutions with the Monte Carlo (MC) solutions for the problem

Extension's Role in Developing a Farmers' Market

Science.gov (United States)

Civittolo, David

2012-01-01

Interest in access to local food is increasing. Communities of all types and sizes have volunteers interested in creating farmers' markets. Extension can play an important role in the development of farmers' markets because it is ideally suited to organize and coordinate these volunteer energies. By helping community volunteers focus…

One step beyond: Different step-to-step transitions exist during continuous contact brachiation in siamangs

Directory of Open Access Journals (Sweden)

Fana Michilsens

2012-02-01

In brachiation, two main gaits are distinguished, ricochetal brachiation and continuous contact brachiation. During ricochetal brachiation, a flight phase exists and the body centre of mass (bCOM describes a parabolic trajectory. For continuous contact brachiation, where at least one hand is always in contact with the substrate, we showed in an earlier paper that four step-to-step transition types occur. We referred to these as a ‘point’, a ‘loop’, a ‘backward pendulum’ and a ‘parabolic’ transition. Only the first two transition types have previously been mentioned in the existing literature on gibbon brachiation. In the current study, we used three-dimensional video and force analysis to describe and characterize these four step-to-step transition types. Results show that, although individual preference occurs, the brachiation strides characterized by each transition type are mainly associated with speed. Yet, these four transitions seem to form a continuum rather than four distinct types. Energy recovery and collision fraction are used as estimators of mechanical efficiency of brachiation and, remarkably, these parameters do not differ between strides with different transition types. All strides show high energy recoveries (mean  = 70±11.4% and low collision fractions (mean  = 0.2±0.13, regardless of the step-to-step transition type used. We conclude that siamangs have efficient means of modifying locomotor speed during continuous contact brachiation by choosing particular step-to-step transition types, which all minimize collision fraction and enhance energy recovery.

Radiation grafting of pH-sensitive acrylic acid and 4-vinyl pyridine onto nylon-6 using one- and two-step methods

International Nuclear Information System (INIS)

Ortega, Alejandra; Alarcón, Darío; Muñoz-Muñoz, Franklin; Garzón-Fontecha, Angélica; Burillo, Guillermina

2015-01-01

Acrylic acid (AAc) and 4-vinyl pyridine (4VP) were γ-ray grafted onto nylon-6 (Ny 6 ) films via pre-irradiation oxidative method. These monomers were grafted using a one-step method to render Ny 6 -g–(AAc/4VP). A two-step or sequential method was used to render (Ny 6 -g–AAc)-g–4VP. Random copolymer branches were obtained when the grafting was carried out via one-step method using the two monomers together. The two-step method was applied to graft chains of 4VP on both Ny 6 substrate and previously grafted AAc chains (Ny 6 -g–AAc). The two types of binary copolymers synthesized were characterized to determine the amount of grafted polymers, the thermal behavior (DSC and TGA), the surface composition (XPS), and the pH responsiveness. In the two-step process, it is possible to achieve a higher graft yield, better control of the amount of each monomer, good reversibility in the swelling/deswelling process and shorter time to achieve equilibrium swelling. - Highlights: • A new binary graft of 4VP and AAc onto Ny 6 films was synthesized by γ-radiation. • The binary grafted material has potential application for heavy ion retention. • The two-step method shows better conditions in swelling and reversibility properties. • Surface distribution of monomers was evaluate by XPS characterization

Using a Two-Step Method to Measure Transgender Identity in Latin America/the Caribbean, Portugal, and Spain

Science.gov (United States)

Reisner, Sari L.; Biello, Katie; Rosenberger, Joshua G.; Austin, S. Bryn; Haneuse, Sebastien; Perez-Brumer, Amaya; Novak, David S.; Mimiaga, Matthew J.

2014-01-01

Few comparative data are available internationally to examine health differences by transgender identity. A barrier to monitoring the health and well-being of transgender people is the lack of inclusion of measures to assess natal sex/gender identity status in surveys. Data were from a cross-sectional anonymous online survey of members (n > 36,000) of a sexual networking website targeting men who have sex with men in Spanish- and Portuguese-speaking countries/ territories in Latin America/the Caribbean, Portugal, and Spain. Natal sex/gender identity status was assessed using a two-step method (Step 1: assigned birth sex, Step 2: current gender identity). Male-to-female (MTF) and female-to-male (FTM) participants were compared to non-transgender males in age-adjusted regression models on socioeconomic status (SES) (education, income, sex work), masculine gender conformity, psychological health and well-being (lifetime suicidality, past-week depressive distress, positive self-worth, general self-rated health, gender related stressors), and sexual health (HIV-infection, past-year STIs, past-3 month unprotected anal or vaginal sex). The two-step method identified 190 transgender participants (0.54%; 158 MTF, 32 FTM). Of the 12 health-related variables, six showed significant differences between the three groups: SES, masculine gender conformity, lifetime suicidality, depressive distress, positive self-worth, and past-year genital herpes. A two-step approach is recommended for health surveillance efforts to assess natal sex/gender identity status. Cognitive testing to formally validate assigned birth sex and current gender identity survey items in Spanish and Portuguese is encouraged. PMID:25030120

Development and design of advanced two-photon microscope used in neuroscience

International Nuclear Information System (INIS)

Doronin, M S; Popov, A V

2016-01-01

This work represents the real steps to development and design advanced two-photon microscope by efforts of laboratory staff. Self-developed microscopy system provides possibility to service it and modify the structure of microscope depending on highly specialized experimental design and scientific goals. We are presenting here module-based microscopy system which provides an opportunity to looking for new applications of this setup depending on laboratories needs using with galvo and resonant scanners. (paper)

Hemolysis research of implantable axial flow pump for two -step heart transplantation in children

Directory of Open Access Journals (Sweden)

O. Yu. Dmitrieva

2017-01-01

Full Text Available Introduction. One of the main indicators characterizing mechanical circulatory support devices (artificial valve, implantable pumps, etc. is trauma of blood cells. Therefore, while developing new pumps, one of the key studies in vitro is to evaluate blood hemolysis. For an objective hemolysis analysis of pump it is required to create a standardized methodology of hemolysis studies. The object of the study in this paper is implantable axial pump DON for two-step heart transplantation in children.The aim of study is to develop a standardized methodology of hemolysis studies of blood pumps and to conduct research of pediatric axial pump DON.Materials and methods. To conduct hemolysis research we created a mock circulatory system consisting of a reservoir placed in water bath maintaining a constant working fluid (blood temperature, hydrodynamic resistance, connecting tubes, ports for blood sampling and pressure and flow measurement systems, and research pump. Test method is to estimate levels of free hemoglobin pHb obtained by blood samples during pump working in operating mode (for pediatric pump: blood flow 2.5 l/min, pressure difference 80 mmHg. Using the data obtained the standardized indices of hemolysis NIH and MIH are calculated based on pHb values, hematocrit, total hemoglobin, blood flow and working pump time.Results. We developed and realized a standardized methodology of hemolysis research by which we evaluated hemolysis of pediatric axial pump. The results of hemolysis tests allowed us to optimize the design of DON. Obtained values of hemolysis of the latest version of pediatric pump DON-3 have shown that they do conform to the requirements of minimum blood injury and it allows us to proceed to the next step of pediatric pump research – animal experiments.Conclusion. Developed methods and evaluation tools of hemolysis allow us to provide objective information on one of the most important indicators of developing

Developing and Testing Twelve-Step Facilitation for Adolescents with Substance Use Disorder: Manual Development and Preliminary Outcomes

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John F. Kelly

2016-01-01

Full Text Available Adolescent substance use disorder treatment programs are often based on the 12-step philosophy of Alcoholics Anonymous and/or link adolescents to these free resources. Despite this, no studies have developed and rigorously tested a twelve-step facilitation (TSF intervention for young people, leaving a significant evidence gap. This study describes the first systematic development of an outpatient adolescent TSF treatment. An integrated twelve-step facilitation (iTSF treatment incorporated TSF, motivational enhancement therapy, and cognitive behavioral therapy elements and was developed in an iterative manner with weekly feedback provided by 36 adolescents ( M age 17 years [SD = 1.4]; 52.8% white with DSM-IV substance use disorder recruited from the community. Assessments were conducted at baseline and at three and six months. Participants completed 6 of 10 sessions on average (8 participants completed all 10. Notable treatment developments were the inclusion of “in-services” led by Marijuana Anonymous members, including parents in a portion of individual sessions to provide a rationale for TSF, and use of a Socratic therapeutic interaction style. Acceptability and feasibility of the treatment were excellent (treatment satisfaction was 4.29 [SD = 0.59] out of 5. In keeping with TSF theory, the intervention substantially increased 12-step participation, and greater participation related to greater abstinence. iTSF is a replicable manualized treatment that can be implemented and tested in outpatient settings. Given the widespread compatibility of iTSF with the current adolescent treatment, if found efficacious, iTSF could be relatively easily adopted, implemented, and sustained and could provide an evidence-based option that could undergird current practice.

Separation of uranium and rare earth elements from Rirang ore leach solution by two-step precipitation

International Nuclear Information System (INIS)

Sradjono; Erni Rifandriyah, A.; Zahardi

1995-01-01

Separation of uranium and rare-earth elements from Rirang ore leach solution was carried out through a two-step precipitation. Several condition affecting the separation processes were examined including solution pH, reagent concentration, and reaction prepitation time. Optimum conditions for the first and second precipitation steps include adjustment of precipitation pH to 1.3 and 2.3, respectively by the addition of 7.3% of NH 4 OH solution and allowing 60 minutes precipitation/reaction time. Based on the conditions, about 6% of Th, 3% of U, 0.9% of PO 4 3- , and none of RE were recovered in the first precipitation step meanwhile, about 99% of RE, 55% of U, 76% of PO 4 3- , and of the Th were recovered in the second step. (author). 3 refs. 4 tabs. 4 figs

Effect of two-step intercritical annealing on microstructure and mechanical properties of hot-rolled medium manganese TRIP steel containing δ-ferrite

International Nuclear Information System (INIS)

Xu, Yun-bo; Hu, Zhi-ping; Zou, Ying; Tan, Xiao-dong; Han, Ding-ting; Chen, Shu-qing; Ma, De-gang; Misra, R.D.K.

2017-01-01

The microstructure-properties relationship, work-hardening behavior and retained austenite stability have been systematically investigated in a hot-rolled medium manganese transformation-induced-plasticity (TRIP) steel containing δ-ferrite subjected to one-step and two-step intercritical annealing. The steel exhibited tensile strength of 752 MPa and total elongation of 52.7% for one-step intercritical annealing at 740 °C, tensile strength of 954 MPa and total elongation of 39.2% in the case of intercritical quenching at 800 °C and annealing at 740 °C. The austenite obtained by two-step annealing mostly consists of refined lath structures and increased fraction of block-type particles existing at various kinds of sites, which is highly distinguished from those characterized by long lath morphology and small amounts of granular shape in one-step annealed samples. In spite of a higher C and Mn content in austenite and finer austenite laths, two-step annealing can lead to an active and continuous TRIP effect provided by a mixed blocky and lath-type austenitic structure with lower stability, contributing to a higher UTS. In contrast, one-step annealing gave rise to a less active but sustained TRIP effect given by the dominant lath-like austenite having higher stability, leading to a very high elongation. The further precipitation of vanadium carbides and the presence of both dislocation substructure and fine equiaxed grain in ferrite matrix facilitate the increase of yield strength after double annealing. - Highlights: • A novel two-step process was applied to a hot-rolled Fe-0.2C-6.5Mn-3Al steel. • The interplay between different microstructures and mechanical properties was studied. • Two-step annealing led to an active and continuous TRIP. • An outstanding combination of strength of 954 MPa and elongation of 39.2% was obtained.

Effect of two-step intercritical annealing on microstructure and mechanical properties of hot-rolled medium manganese TRIP steel containing δ-ferrite

Energy Technology Data Exchange (ETDEWEB)

Xu, Yun-bo [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, People' s Republic China (China); Hu, Zhi-ping, E-mail: huzhiping900401@126.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, People' s Republic China (China); Zou, Ying; Tan, Xiao-dong; Han, Ding-ting; Chen, Shu-qing [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, People' s Republic China (China); Ma, De-gang [Tangshan Iron and Steel Company, Tangshan 063000, People' s Republic China (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials and Biomedical Engineering, University of Texas at El Paso, TX 79968 (United States)

2017-03-14

The microstructure-properties relationship, work-hardening behavior and retained austenite stability have been systematically investigated in a hot-rolled medium manganese transformation-induced-plasticity (TRIP) steel containing δ-ferrite subjected to one-step and two-step intercritical annealing. The steel exhibited tensile strength of 752 MPa and total elongation of 52.7% for one-step intercritical annealing at 740 °C, tensile strength of 954 MPa and total elongation of 39.2% in the case of intercritical quenching at 800 °C and annealing at 740 °C. The austenite obtained by two-step annealing mostly consists of refined lath structures and increased fraction of block-type particles existing at various kinds of sites, which is highly distinguished from those characterized by long lath morphology and small amounts of granular shape in one-step annealed samples. In spite of a higher C and Mn content in austenite and finer austenite laths, two-step annealing can lead to an active and continuous TRIP effect provided by a mixed blocky and lath-type austenitic structure with lower stability, contributing to a higher UTS. In contrast, one-step annealing gave rise to a less active but sustained TRIP effect given by the dominant lath-like austenite having higher stability, leading to a very high elongation. The further precipitation of vanadium carbides and the presence of both dislocation substructure and fine equiaxed grain in ferrite matrix facilitate the increase of yield strength after double annealing. - Highlights: • A novel two-step process was applied to a hot-rolled Fe-0.2C-6.5Mn-3Al steel. • The interplay between different microstructures and mechanical properties was studied. • Two-step annealing led to an active and continuous TRIP. • An outstanding combination of strength of 954 MPa and elongation of 39.2% was obtained.

A two-step FEM-SEM approach for wave propagation analysis in cable structures

Science.gov (United States)

Zhang, Songhan; Shen, Ruili; Wang, Tao; De Roeck, Guido; Lombaert, Geert

2018-02-01

Vibration-based methods are among the most widely studied in structural health monitoring (SHM). It is well known, however, that the low-order modes, characterizing the global dynamic behaviour of structures, are relatively insensitive to local damage. Such local damage may be easier to detect by methods based on wave propagation which involve local high frequency behaviour. The present work considers the numerical analysis of wave propagation in cables. A two-step approach is proposed which allows taking into account the cable sag and the distribution of the axial forces in the wave propagation analysis. In the first step, the static deformation and internal forces are obtained by the finite element method (FEM), taking into account geometric nonlinear effects. In the second step, the results from the static analysis are used to define the initial state of the dynamic analysis which is performed by means of the spectral element method (SEM). The use of the SEM in the second step of the analysis allows for a significant reduction in computational costs as compared to a FE analysis. This methodology is first verified by means of a full FE analysis for a single stretched cable. Next, simulations are made to study the effects of damage in a single stretched cable and a cable-supported truss. The results of the simulations show how damage significantly affects the high frequency response, confirming the potential of wave propagation based methods for SHM.

Discrimination between Native and Tn6010-Associated oqxAB in Klebsiella spp., Raoultella spp., and other Enterobacteriaceae by Using a Two-Step Strategy

DEFF Research Database (Denmark)

Guillard, Thomas; Lebreil, Anne-Laure; Hansen, Lars Hestbjerg

2015-01-01

ABSTRACT We developed a two-step PCR-based strategy to detect genes encoding OqxAB, allowing a specific assignment of Tn6010-associated oqxAB in Enterobacteriaceae. Chromosomal location in this setup was confirmed by hybridization with I-CeuI-restricted genomes. This approach led us to find...

CAPACITY BUILDING FOR CLIMATE CHANGE ADAPTATION: MODULES FOR AGRICULTURAL EXTENSION CURRICULUM DEVELOPMENT

Directory of Open Access Journals (Sweden)

B.O. Ogunbameru

2013-02-01

Full Text Available Basically, climate change refers to any change in climate overtime, generally caused by natural variability and/or human activities. It has great devastating impact, particularly on agriculture and by extrapolation on farmers and the national economy. The frontline agricultural extension workers are expected to be among the principal stakeholders to teach farmers how to cope with climate change. Consequently, there is a need to develop appropriate teaching package for the training of the frontline agricultural extension workers, based on the myriad of adaptation strategies and practices available in the literature. This paper synthesizes the rationale for capacity building in climate change and the adaptation or coping strategies. The modules (train-the-trainer for teaching agricultural extension workers and farmers are documented in the paper.

Two-step purification of scutellarin from Erigeron breviscapus (vant.) Hand. Mazz. by high-speed counter-current chromatography.

Science.gov (United States)

Gao, Min; Gu, Ming; Liu, Chun-Zhao

2006-07-11

Scutellarin, a flavone glycoside, popularly applied for the treatment of cardiopathy, has been purified in two-step purification by high-speed counter-current chromatography (HSCCC) from Erigeron breviscapus (vant.) Hand. Mazz. (Deng-zhan-hua in Chinese), a well-known traditional Chinese medicinal plant for heart disease. Two solvent systems, n-hexane-ethyl acetate-methanol-acetic acid-water (1:6:1.5:1:4, v/v/v/v/v) and ethyl acetate-n-butanol-acetonitrile-0.1% HCl (5:2:5:10, v/v/v/v) were used for the two-step purification. The purity of the collected fraction of scutellarin was 95.6%. This study supplies a new alternative method for purification of scutellarin.

Minimizing cows' stress when calves were early weaned using the two-step method with nose flaps.

Science.gov (United States)

Ungerfeld, R; Quintans, G; Hötzel, M J

2016-11-01

Early weaning may be used in beef cattle production to improve reproduction rates in range conditions. However, weaning causes a stress response in cows, which may be especially strong in early weaning management, as the bond between the cow and the calf is still strong. We hypothesized that weaning calves in two steps, with the aid of anti-sucking devices (nose flaps) would reduce the behavioural stress response in the cows separated from their calves 2 months after parturition. We compared the behaviour frequency and weight change in cows that were weaned abruptly, by separation of the calf on day 0 of the study, or in two steps, consisting of the use of anti-sucking nose flaps for 5 days before permanent separation; a third group was not weaned to serve as control. Thirty-six crossbred multiparous Aberdeen Angus×Hereford cows and their calves (n=12/treatment) were managed in three paddocks with similar pasture availability, with four dyads from each treatment per paddock. Cows' behaviour was observed by direct visual instantaneous sampling, at 10 min intervals from days -3 to 11. Weaning the calves in two steps clearly attenuated the behavioural stress response observed in abruptly weaned cows, which included reductions in grazing and lying, and increases in pacing, walking and vocalizing. Our results corroborate those previously shown for cows nursing older calves, and indicate that step weaning can reduce the behavioural stress response of cows at weaning, even when the calf is weaned shortly after birth, when the bond between the cow and calf is still very strong.

Fabrication of ITO-rGO/Ag NPs nanocomposite by two-step chronoamperometry electrodeposition and its characterization as SERS substrate

International Nuclear Information System (INIS)

Wang, Rong; Xu, Yi; Wang, Chunyan; Zhao, Huazhou; Wang, Renjie; Liao, Xin; Chen, Li; Chen, Gang

2015-01-01

Highlights: • A novel structure of ITO-rGO/Ag NPs substrate was developed for SERS application. • Two-step chronoamperometry deposition method was used to prepare SERS substrate. • The SERS substrate had high SERS activity, good uniformity and reproducibility. - Abstract: A novel composite structure of reduced graphene oxide (rGO)–Ag nanoparticles (Ag NPs) nanocomposite, which was integrated on the indium tin oxide (ITO) glass by a facile and rapid two-step chronoamperometry electrodeposition route, was proposed and developed in this paper. SERS-activity of the rGO/Ag NPs nanocomposite was mainly affected by the structure and size of the fabricated rGO/Ag NPs nanocomposite. In the experiments, the operational conditions of electrodeposition process were studied in details. The electrodeposited time was the important controllable factor, which decided the particle size and surface coverage of the deposited Ag NPs on ITO glass. Under the optimized conditions, the detection limit for rhodamine6G (R6G) was as low as 10 −11 M and the Raman enhancement factor was as large as 5.9 × 10 8 , which was 24 times higher than that for the ITO–Ag NPs substrate. Apart from this higher enhancement effect, it was also illustrated that extremely good uniformity and reproducibility with low standard deviation could be obtained by the prepared ITO-rGO/Ag NPs nanocomposite for SRES detection

A two-step recognition of signal sequences determines the translocation efficiency of proteins.

Science.gov (United States)

Belin, D; Bost, S; Vassalli, J D; Strub, K

1996-02-01

The cytosolic and secreted, N-glycosylated, forms of plasminogen activator inhibitor-2 (PAI-2) are generated by facultative translocation. To study the molecular events that result in the bi-topological distribution of proteins, we determined in vitro the capacities of several signal sequences to bind the signal recognition particle (SRP) during targeting, and to promote vectorial transport of murine PAI-2 (mPAI-2). Interestingly, the six signal sequences we compared (mPAI-2 and three mutated derivatives thereof, ovalbumin and preprolactin) were found to have the differential activities in the two events. For example, the mPAI-2 signal sequence first binds SRP with moderate efficiency and secondly promotes the vectorial transport of only a fraction of the SRP-bound nascent chains. Our results provide evidence that the translocation efficiency of proteins can be controlled by the recognition of their signal sequences at two steps: during SRP-mediated targeting and during formation of a committed translocation complex. This second recognition may occur at several time points during the insertion/translocation step. In conclusion, signal sequences have a more complex structure than previously anticipated, allowing for multiple and independent interactions with the translocation machinery.

Development of One Dimensional Hyperbolic Coupled Solver for Two-Phase Flows

International Nuclear Information System (INIS)

Kim, Eoi Jin; Kim, Jong Tae; Jeong, Jae June

2008-08-01

The purpose of this study is a code development for one dimensional two-phase two-fluid flows. In this study, the computations of two-phase flow were performed by using the Roe scheme which is one of the upwind schemes. The upwind scheme is widely used in the computational fluid dynamics because it can capture discontinuities clearly such as a shock. And this scheme is applicable to multi-phase flows by the extension methods which were developed by Toumi, Stadtke, etc. In this study, the extended Roe upwind scheme by Toumi for two-phase flow was implemented in the one-dimensional code. The scheme was applied to a shock tube problem and a water faucet problem. This numerical method seems efficient for non oscillating solutions of two phase flow problems, and also capable for capturing discontinuities

Development of One Dimensional Hyperbolic Coupled Solver for Two-Phase Flows

Energy Technology Data Exchange (ETDEWEB)

Kim, Eoi Jin; Kim, Jong Tae; Jeong, Jae June

2008-08-15

The purpose of this study is a code development for one dimensional two-phase two-fluid flows. In this study, the computations of two-phase flow were performed by using the Roe scheme which is one of the upwind schemes. The upwind scheme is widely used in the computational fluid dynamics because it can capture discontinuities clearly such as a shock. And this scheme is applicable to multi-phase flows by the extension methods which were developed by Toumi, Stadtke, etc. In this study, the extended Roe upwind scheme by Toumi for two-phase flow was implemented in the one-dimensional code. The scheme was applied to a shock tube problem and a water faucet problem. This numerical method seems efficient for non oscillating solutions of two phase flow problems, and also capable for capturing discontinuities.

The 12 Steps of Addiction Recovery Programs as an influence on leadership development: a personal narrative

Directory of Open Access Journals (Sweden)

Friedman Mitchell

2016-12-01

Full Text Available My participation in a 12-step addiction program based on the principles and traditions of Alcoholics Anonymous (AA has been critical for my leadership development. As I worked to refrain from addictive behaviors and practiced 12-step principles, I experienced a shift from individualistic, self-centered leadership towards a servant leader orientation. I thus consider the 12-step recovery process, which commenced in 2001, a leadership formative experience (LFE as it had the greatest influence on my subsequent development. My experience of thinking about and rethinking my life in reference to leadership and followership lends itself to a personal inquiry. It draws on work on the12 steps; self-assessments and personal journal entries; and memory of life events. I aim to contribute to the leadership development literature by exploring the influence of participation in a 12-step recovery program and posing it as an LFE, subjects that have received little attention.

Tailoring structures through two-step annealing process in nanostructured aluminum produced by accumulative roll-bonding

DEFF Research Database (Denmark)

Kamikawa, Naoya; Huang, Xiaoxu; Hansen, Niels

2008-01-01

temperature before annealing at high temperature. By this two-step process, the structure is homogenized and the stored energy is reduced significantly during the first annealing step. As an example, high-purity aluminum has been deformed to a total reduction of 98.4% (equivalent strain of 4.......8) by accumulative roll-bonding at room temperature. Isochronal annealing for 0.5 h of the deformed samples shows the occurrence of recrystallization at 200 °C and above. However, when introducing an annealing step for 6 h at 175 °C, no significant recrystallization is observed and relatively homogeneous structures...... are obtained when the samples afterwards are annealed at higher temperatures up to 300 °C. To underpin these observations, the structural evolution has been characterized by transmission electron microscopy, showing that significant annihilation of high-angle boundaries, low-angle dislocation boundaries...

Microleakage assessment of one- and two-step self-etch adhesive systems with ‎the low shrinkage composites

Directory of Open Access Journals (Sweden)

Razieh Hoseinifar

2015-07-01

Full Text Available BACKGROUND AND AIM: Different studies evaluating one-step self-etch (SE adhesive systems show contradictory findings, so the aim of this study was to compare the microleakage of one-step SE adhesive systems and CLEARFIL SE BOND (that serves as the “gold-standard” SE adhesive with low shrinkage composites. METHODS: In this in vitro study, Class V cavities with the occlusal margin in enamel and cervical margin in cementum were prepared on the buccal and lingual surfaces of 36 human premolars and molars (72 cavities. The enamel surfaces of the cavities were etched with 37% phosphoric acid and then the specimens were divided into six groups of 6 (12 cavities and the cavities were restored according bellow: Group 1 (Kalore-GC + G-Bond, Group 2 (Grandio + Futurabond NR, Group 3 (Aelite LS Posterior + All Bond SE, Group 4 (Kalore-GC + CLEARFIL SE BOND, Group 5 (Grandio + CLEARFIL SE BOND, and Group 6 (Aelite LS Posterior + CLEARFIL SE BOND. All the specimens were thermocycled for 2000 cycles (5-55 °C and then placed in 0.5% basic fuchsine dye for 24 hours at 37 °C and finally sectioned and observed under the stereomicroscope. Data were analyzed using Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests at a P 0.050. There were no significant differences in microleakage among two-step and one-step SE adhesive systems on both the occlusal and gingival margins. CONCLUSION: According to this study, two-step SE adhesive system (CLEARFIL SE BOND did not provide better marginal seal than the one-step SE adhesive systems.

Novel Two-Step Classifier for Torsades de Pointes Risk Stratification from Direct Features

Directory of Open Access Journals (Sweden)

Jaimit Parikh

2017-11-01

Full Text Available While pre-clinical Torsades de Pointes (TdP risk classifiers had initially been based on drug-induced block of hERG potassium channels, it is now well established that improved risk prediction can be achieved by considering block of non-hERG ion channels. The current multi-channel TdP classifiers can be categorized into two classes. First, the classifiers that take as input the values of drug-induced block of ion channels (direct features. Second, the classifiers that are built on features extracted from output of the drug-induced multi-channel blockage simulations in the in-silico models (derived features. The classifiers built on derived features have thus far not consistently provided increased prediction accuracies, and hence casts doubt on the value of such approaches given the cost of including biophysical detail. Here, we propose a new two-step method for TdP risk classification, referred to as Multi-Channel Blockage at Early After Depolarization (MCB@EAD. In the first step, we classified the compound that produced insufficient hERG block as non-torsadogenic. In the second step, the role of non-hERG channels to modulate TdP risk are considered by constructing classifiers based on direct or derived features at critical hERG block concentrations that generates EADs in the computational cardiac cell models. MCB@EAD provides comparable or superior TdP risk classification of the drugs from the direct features in tests against published methods. TdP risk for the drugs highly correlated to the propensity to generate EADs in the model. However, the derived features of the biophysical models did not improve the predictive capability for TdP risk assessment.

Energy Extension Service Pilot Program: evaluation report after two years. Volume II. State reports

Energy Technology Data Exchange (ETDEWEB)

None

1980-04-01

This report, Vol. II, presents a discussion of the operations of the ten EES pilot state programs during the period from October 1, 1977 through September 30, 1979. Each of the ten pilot states - Alabama, Connecticut, Michigan, New Mexico, Pennsylvania, Tennessee, Texas, Washington, Wisconsin, and Wyoming - received a grant of approximately $1.1 million to develop and implement an 18-month program beginning on October 1, 1977. In September 1978, each State received an additional $370,000 for service-delivery programs for the extension of the pilot program, April 1979 through September 1979. A case-study description of the operations of the pilot program in each State is provided here, with special attention given to the two programs selected in each State for more-detailed study and survey research. Although the thrust of this volume is descriptive, some survey data and analyses are presented for the emphasis programs. Two telephone surveys of clients and a non-client sample were conducted, one at the end of the first year of the pilot program (October 1977 - September 1978) and one at the end of the second year (October 1978 - September 1979).

Two-step technique for posterior optic buttonholing of intraocular lens.

Science.gov (United States)

Agarwal, Tushar; Jhanji, Vishal; Singh, Digvijay; Khokhar, Sudarshan

2014-04-01

This study aims to describe a two-step surgical technique for placement of a posterior chamber intraocular lens (IOL) in cases with crystalline lens subluxation resulting from non-progressive zonular dialysis. The first stage entails a phacoemulsification with creation of a 4-mm posterior capsular opening using an automated vitrector. The second stage performed 6 weeks later includes an anterior vitrectomy and injection of a foldable three-piece IOL in the sulcus. The haptics of IOL are positioned in the sulcus while the optic is pushed behind the posterior capsular opening therefore "buttonholing" the IOL. Seven eyes of seven patients with posttraumatic zonular dialysis were operated using this technique. Follow-up of all cases revealed a well-centered IOL with good postoperative visual acuity (20/20 to 20/80). Our two-stage surgical technique precludes the insertion of capsular tension ring in cases with non-progressive zonular dialysis. The technique is recommended in the presence of less than or equal to 6 clock hours of zonular dialysis with preexisting posterior capsular tear or herniation of vitreous in the anterior chamber.

New Bayesian inference method using two steps of Markov chain Monte Carlo and its application to shock tube experiment data of Furan oxidation

KAUST Repository

Kim, Daesang

2016-01-06

A new Bayesian inference method has been developed and applied to Furan shock tube experimental data for efficient statistical inferences of the Arrhenius parameters of two OH radical consumption reactions. The collected experimental data, which consist of time series signals of OH radical concentrations of 14 shock tube experiments, may require several days for MCMC computations even with the support of a fast surrogate of the combustion simulation model, while the new method reduces it to several hours by splitting the process into two steps of MCMC: the first inference of rate constants and the second inference of the Arrhenius parameters. Each step has low dimensional parameter spaces and the second step does not need the executions of the combustion simulation. Furthermore, the new approach has more flexibility in choosing the ranges of the inference parameters, and the higher speed and flexibility enable the more accurate inferences and the analyses of the propagation of errors in the measured temperatures and the alignment of the experimental time to the inference results.

The Value of Step-by-Step Risk Assessment for Unmanned Aircraft

DEFF Research Database (Denmark)

La Cour-Harbo, Anders

2018-01-01

The new European legislation expected in 2018 or 2019 will introduce a step-by-step process for conducting risk assessments for unmanned aircraft flight operations. This is a relatively simple approach to a very complex challenge. This work compares this step-by-step process to high fidelity risk...... modeling, and shows that at least for a series of example flight missions there is reasonable agreement between the two very different methods....

Single step synthesis, characterization and applications of curcumin functionalized iron oxide magnetic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Bhandari, Rohit; Gupta, Prachi; Dziubla, Thomas; Hilt, J. Zach, E-mail: zach.hilt@uky.edu

2016-10-01

Magnetic iron oxide nanoparticles have been well known for their applications in magnetic resonance imaging (MRI), hyperthermia, targeted drug delivery, etc. The surface modification of these magnetic nanoparticles has been explored extensively to achieve functionalized materials with potential application in biomedical, environmental and catalysis field. Herein, we report a novel and versatile single step methodology for developing curcumin functionalized magnetic Fe{sub 3}O{sub 4} nanoparticles without any additional linkers, using a simple coprecipitation technique. The magnetic nanoparticles (MNPs) were characterized using transmission electron microscopy, X-ray diffraction, fourier transform infrared spectroscopy and thermogravimetric analysis. The developed MNPs were employed in a cellular application for protection against an inflammatory agent, a polychlorinated biphenyl (PCB) molecule. - Graphical abstract: Novel single step curcumin coated magnetic Fe{sub 3}O{sub 4} nanoparticles without any additional linkers for medical, environmental, and other applications. Display Omitted - Highlights: • A novel and versatile single step methodology for developing curcumin functionalized magnetic Fe{sub 3}O{sub 4} nanoparticles is reported. • The magnetic nanoparticles (MNPs) were characterized using TEM, XRD, FTIR and TGA. • The developed MNPs were employed in a cellular application for protection against an inflammatory agent, a polychlorinated biphenyl (PCB).

Advancing the Public Value Movement: Sustaining Extension during Tough Times

Science.gov (United States)

Franz, Nancy K.

2011-01-01

Extension must more fully and adeptly embrace the public value movement to be sustainable as a publicly funded organization, or our demise as an organization will continue. The public value steps outlined here and piloted with several Extension systems and national work groups can be informative for others interested in capturing and sharing the…

Evaluation of one-step luminescent cyanoacrylate fuming.

Science.gov (United States)

Khuu, Alicia; Chadwick, Scott; Spindler, Xanthe; Lam, Rolanda; Moret, Sébastien; Roux, Claude

2016-06-01

One-step luminescent cyanoacrylates have recently been introduced as an alternative to the conventional cyanoacrylate fuming methods. These new techniques do not require the application of a luminescent post-treatment in order to enhance cyanoacrylate-developed fingermarks. In this study, three one-step polymer cyanoacrylates: CN Yellow Crystals (Aneval Inc.), PolyCyano UV (Foster+Freeman Ltd.) and PECA Multiband (BVDA), and one monomer cyanoacrylate: Lumikit™ (Crime Scene Technology), were evaluated against a conventional two-step cyanoacrylate fuming method (Cyanobloom (Foster+Freeman Ltd.) with rhodamine 6G stain). The manufacturers' recommended conditions or conditions compatible with the MVC™ 1000/D (Foster+Freeman Ltd.) were assessed with fingermarks aged for up to 8 weeks on non-porous and semi-porous substrates. Under white light, Cyanobloom generally gave better development than the one-step treatments across the substrates. Similarly when viewed under the respective luminescent conditions, Cyanobloom with rhodamine 6G stain resulted in improved contrast against the one-step treatments except on polystyrene, where PolyCyano UV and PECA Multiband gave better visualisation. Rhodamine 6G post-treatment of one-step samples did not significantly enhance the contrast of any of the one-step treatments against Cyanobloom/rhodamine 6G-treated samples. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

An improved protocol and a new grinding device for extraction of genomic DNA from microorganisms by a two-step extraction procedure.

Science.gov (United States)

Zhang, S S; Chen, D; Lu, Q

2012-05-21

Current protocols to extract genomic DNA from microorganisms are still laborious, tedious and costly, especially for the species with thick cell walls. In order to improve the effectiveness of extracting DNA from microbial samples, a novel protocol, defined as two-step extraction method, along with an improved tissue-grinding device, was developed. The protocol included two steps, disruption of microbial cells or spores by grinding the sample together with silica sand in a new device and extraction of DNA with an effective buffer containing cell lysis chemicals. The device was prepared by using a commercial electric mini-grinder, adapted with a grinding stone, and a sample cup processed by lathing from a polytetrafluoroethylene rod. We tested the method with vegetative cells of four microbial species and two microbial spores that have thick cell walls and are therefore hard to process; these included Escherichia coli JM109, Bacillus subtilis WB600, Sacchromyces cerevisiae INVSc1, Trichoderma viride AS3.3711, and the spores of S. cerevisiae and T. viride, respectively, representing Gram-positive bacteria, Gram-negative bacteria, yeast, filamentous fungi. We found that this new method and device extracted usable quantities of genomic DNA from the samples. The DNA fragments that were extracted exceeded 23 kb. The target sequences up to about 5 kb were successfully and exclusively amplified by PCR using extracted DNA as the template. In addition, the DNA extraction was finalized within 1.5 h. Thus, we conclude that this two-step extraction method is an effective and improved protocol for extraction of genomic DNA from microbial samples.

A ten-step process to develop case management plans.

Science.gov (United States)

Tahan, Hussein A

2002-01-01

The use of case management plans has contained cost and improved quality of care successfully. However, the process of developing these plans remains a great challenge for healthcare executives, in this article, the author presents the answer to this challenge by discussing a 10-step formal process that administrators of patient care services and case managers can adapt to their institutions. It also can be used by interdisciplinary team members as a practical guide to develop a specific case management plan. This process is applicable to any care setting (acute, ambulatory, long term, and home care), diagnosis, or procedure. It is particularly important for those organizations that currently do not have a deliberate and systematic process to develop case management plans and are struggling with how to improve the efficiency and productivity of interdisciplinary teams charged with developing case management plans.

Priorities for Extension.

Science.gov (United States)

Hayward, J. A.

Agricultural extension is one component in an array including research, training, education, marketing, international trade, etc. which develop together to bring about growth, and sustained growth determines the priorities for extension. These priorities depend inevitably on the stage of development of a country or region, and on the current…

Extended Kalman filter (EKF) application in vitamin C two-step fermentation process.

Science.gov (United States)

Wei, D; Yuan, W; Yuan, Z; Yin, G; Chen, M

1993-01-01

Based on kinetic model study of vitamin C two-step fermentation, the extended Kalman filter (EKF) theory is conducted for studying the process which is disturbed by white noise to some extent caused by the model, the fermentation system and operation fluctuation. EKF shows that calculated results from estimated process parameters agree with the experimental results considerably better than model prediction without using estimated parameters. Parameter analysis gives a better understanding of the kinetics and provides a basis for state estimation and state prediction.

A cascaded two-step Kalman filter for estimation of human body segment orientation using MEMS-IMU.

Science.gov (United States)

Zihajehzadeh, S; Loh, D; Lee, M; Hoskinson, R; Park, E J

2014-01-01

Orientation of human body segments is an important quantity in many biomechanical analyses. To get robust and drift-free 3-D orientation, raw data from miniature body worn MEMS-based inertial measurement units (IMU) should be blended in a Kalman filter. Aiming at less computational cost, this work presents a novel cascaded two-step Kalman filter orientation estimation algorithm. Tilt angles are estimated in the first step of the proposed cascaded Kalman filter. The estimated tilt angles are passed to the second step of the filter for yaw angle calculation. The orientation results are benchmarked against the ones from a highly accurate tactical grade IMU. Experimental results reveal that the proposed algorithm provides robust orientation estimation in both kinematically and magnetically disturbed conditions.

A two-step obtainment of quantum confinement in ZnO nanorods

Energy Technology Data Exchange (ETDEWEB)

Mofor, A C; El-Shaer, A; Suleiman, M; Bakin, A; Waag, A [Institute of Semiconductor Technology, Technical University Braunschweig, Hans-Sommer-Strasse 66, D-38106 Braunschweig (Germany)

2006-10-14

ZnO nanorod-based single quantum well heterostructures were fabricated in a two-step process. Nanorods were first grown using vapour transport. Subsequently, high-quality ZnO/Zn{sub 0.85}Mg{sub 0.15}O heterostructures were grown on the nanorods using molecular beam epitaxy. The nanorods are well aligned along the c-axis of ZnO, as indicated by a very narrow rocking curve full width at half maximum. Quantum confinement was clearly observed within the ZnO well for different well widths. The quantum wells show photoluminescence peaks with a full width at half maximum as small as 15 meV.

A Data-Driven Approach to SEM Development at a Two-Year College

Science.gov (United States)

Pirius, Landon K.

2014-01-01

This article explores implementation of strategic enrollment management (SEM) at a two-year college and why SEM is critical to the long-term viability of an institution. This article also outlines the five initial steps needed to implement SEM, including identifying SEM leadership, building a SEM committee, developing a common understanding of…

Characteristic analysis of laser isotope separation process by two-step photodissociation method

International Nuclear Information System (INIS)

Okamoto, Tsuyoshi; Suzuki, Atsuyuki; Kiyose, Ryohei

1981-01-01

A large number of laser isotope separation experiments have been performed actively in many countries. In this paper, the selective two-step photodissociation method is chosen and simultaneous nonlinear differential equations that express the separation process are solved directly by using computer. Predicted separation factors are investigated in relation to the incident pulse energy and the concentration of desired molecules. Furthermore, the concept of separative work is used to evaluate the results of separation for this method. It is shown from an example of numerical calculation that a very large separation factor can be obtained if the concentration of desired molecules is lowered and two laser pulses to be closely synchronized are not always required in operation for the photodissociation of molecules. (author)

Microsoft Office professional 2010 step by step

CERN Document Server

Cox, Joyce; Frye, Curtis

2011-01-01

Teach yourself exactly what you need to know about using Office Professional 2010-one step at a time! With STEP BY STEP, you build and practice new skills hands-on, at your own pace. Covering Microsoft Word, PowerPoint, Outlook, Excel, Access, Publisher, and OneNote, this book will help you learn the core features and capabilities needed to: Create attractive documents, publications, and spreadsheetsManage your e-mail, calendar, meetings, and communicationsPut your business data to workDevelop and deliver great presentationsOrganize your ideas and notes in one placeConnect, share, and accom

Prenylcoumarins in One or Two Steps by a Microwave-Promoted Tandem Claisen Rearrangement/Wittig Olefination/Cyclization Sequence.

Science.gov (United States)

Schultze, Christiane; Schmidt, Bernd

2018-05-04

The one-pot synthesis of 8-prenylcoumarins from 1,1-dimethylallylated salicylaldehydes and the stabilized ylide [(ethoxycarbonyl)methylene]triphenylphosphorane under microwave conditions was found to have a limited scope. The sequence suffers from a difficult and sometimes low-yielding synthesis of the precursors and from a competing deprenylation upon microwave irradiation. This side reaction occurs in particular with electron rich arenes with two or more alkoxy groups at adjacent positions, a prominent substitution pattern in naturally occurring 8-prenylcoumarins. Both limitations of this one-step sequence were overcome by a two-step synthesis consisting of a microwave-promoted tandem allyl ether Claisen rearrangement/Wittig olefination and a subsequent olefin cross metathesis with 2-methyl-2-butene. The cross metathesis step proceeds with a high selectivity and yields exclusively the desired prenyl, rather than the alternative crotyl substituent. Several naturally occurring 8-prenylcoumarins that were previously inaccessible have been synthesized in good overall yields along this route.

SiO2 sol-gel films after ammonia and heat two-step treatments

International Nuclear Information System (INIS)

Zhang Chunlai; Wang Biyi; Tian Dongbin; Yin Wei; Jiang Xiaodong; Yuan Xiaodong; Yan Lianghong; Zhang Hongliang; Zhao Songnan; Lv Haibing

2008-01-01

SiO 2 thin films were deposited using tetraethoxylsilane as precursor, ammonia as catalyst on K9 glass by sol-gel method. These films were post-treated by ammonia and heat. The properties of the coatings were characterized by ellipsometer, UV-vis spectrophotometry, FTIR-spectroscopy, scanning probe microscope and contact angle measurement apparatus. The resuits indicate that the thickness of the films with ammonia and heat treatment tend to decrease. Both the refractive index and water contact angle increase after ammonia treatment. However, they both decrease after heat treatment. The former increases by 0.236 for the first step, then decreases by 0.202 for the second. The latter increases to 58.92 degree, then decreases to 38.07 degree. The transmittance of the coatings turn to be better and continuously shift to short wave by UV-vis spectrophotometry. The surface becomes smoother by AFM after the two-step treatment. (authors)

Photon strength function in the Hf-181 nucleus by method of two-step cascade

International Nuclear Information System (INIS)

Le Hong Khiem

2003-01-01

The applicability of sum-coincidence measurements of two-step cascade gamma ray spectra determining Photon Strength Function (PSF) of Hf-181 induced from Hf-180 (n,2γ) Hf-181 reaction is presented. Up to 80% intensity of the primary gamma ray transitions in a wide energy range have been deduced and compared to model calculation. (author)

Synthesis of core/shell ZnO/ZnSe nanowires using novel low cost two-steps electrochemical deposition technique

Energy Technology Data Exchange (ETDEWEB)

Ghoul, M., E-mail: ghoulmed2009@yahoo.fr [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l' Energie Technopole BorjCedria, Bp 95, Hammammlif 2050 (Tunisia); Braiek, Z. [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l' Energie Technopole BorjCedria, Bp 95, Hammammlif 2050 (Tunisia); Brayek, A. [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l' Energie Technopole BorjCedria, Bp 95, Hammammlif 2050 (Tunisia); ITODYS, Université Paris Diderot, Sorbonne Paris Cité, CNRS UMR – 7086, 75205 Paris (France); Ben Assaker, I.; Khalifa, N.; Ben Naceur, J.; Souissi, A.; Lamouchi, A. [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l' Energie Technopole BorjCedria, Bp 95, Hammammlif 2050 (Tunisia); Ammar, S. [ITODYS, Université Paris Diderot, Sorbonne Paris Cité, CNRS UMR – 7086, 75205 Paris (France); Chtourou, R. [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l' Energie Technopole BorjCedria, Bp 95, Hammammlif 2050 (Tunisia)

2015-10-25

This work highlights the original use of a two-step electrochemical deposition protocol to grow ZnO/ZnSe core/shell nanowires on a Sn-doped In{sub 2}O{sub 3} (ITO)/glass substrate. The good alignment of the nanowires is verified by the scanning electron microscopy characterization technique in addition to the surface roughness after the ZnSe electrodeposition on the ZnO nanowires lateral facets. The X-ray diffraction patterns and Raman spectra allow estimating that ZnO has grown along the wurtzite (W) structure c-axis. The presence of the type-II interfacial transition between the valence band of ZnSe and the conduction band of ZnO was confirmed by UV–visible spectroscopy. It was proved that the absorbed energy of the developed nanostructures is extended to the near infrared which is well recommended for the photovoltaic applications. - Graphical abstract: Fabrication of the ZnO–ZnSe core–shell nanowires through a solution based all-electrochemical approach, and their application as photoanodes in photoelectrochemical water splitting cells. - Highlights: • Deposition of ZnO/ZnSe nanowires by two steps electrodeposition method. • The morphology studies show the formation of ZnO/ZnSe core/Shell nanowires. • XRD and Raman spectroscopy confirm the presence of the wurtzite ZnO and blende ZnSe junction. • Optical properties demonstrate the evidence type-II interfacial transition between the two semiconductors.

Two-step single slope/SAR ADC with error correction for CMOS image sensor.

Science.gov (United States)

Tang, Fang; Bermak, Amine; Amira, Abbes; Amor Benammar, Mohieddine; He, Debiao; Zhao, Xiaojin

2014-01-01

Conventional two-step ADC for CMOS image sensor requires full resolution noise performance in the first stage single slope ADC, leading to high power consumption and large chip area. This paper presents an 11-bit two-step single slope/successive approximation register (SAR) ADC scheme for CMOS image sensor applications. The first stage single slope ADC generates a 3-bit data and 1 redundant bit. The redundant bit is combined with the following 8-bit SAR ADC output code using a proposed error correction algorithm. Instead of requiring full resolution noise performance, the first stage single slope circuit of the proposed ADC can tolerate up to 3.125% quantization noise. With the proposed error correction mechanism, the power consumption and chip area of the single slope ADC are significantly reduced. The prototype ADC is fabricated using 0.18 μ m CMOS technology. The chip area of the proposed ADC is 7 μ m × 500 μ m. The measurement results show that the energy efficiency figure-of-merit (FOM) of the proposed ADC core is only 125 pJ/sample under 1.4 V power supply and the chip area efficiency is 84 k  μ m(2) · cycles/sample.

Two-Step Single Slope/SAR ADC with Error Correction for CMOS Image Sensor

Directory of Open Access Journals (Sweden)

Fang Tang

2014-01-01

Full Text Available Conventional two-step ADC for CMOS image sensor requires full resolution noise performance in the first stage single slope ADC, leading to high power consumption and large chip area. This paper presents an 11-bit two-step single slope/successive approximation register (SAR ADC scheme for CMOS image sensor applications. The first stage single slope ADC generates a 3-bit data and 1 redundant bit. The redundant bit is combined with the following 8-bit SAR ADC output code using a proposed error correction algorithm. Instead of requiring full resolution noise performance, the first stage single slope circuit of the proposed ADC can tolerate up to 3.125% quantization noise. With the proposed error correction mechanism, the power consumption and chip area of the single slope ADC are significantly reduced. The prototype ADC is fabricated using 0.18 μm CMOS technology. The chip area of the proposed ADC is 7 μm × 500 μm. The measurement results show that the energy efficiency figure-of-merit (FOM of the proposed ADC core is only 125 pJ/sample under 1.4 V power supply and the chip area efficiency is 84 k μm2·cycles/sample.

xSPDE: Extensible software for stochastic equations

Directory of Open Access Journals (Sweden)

Simon Kiesewetter

2016-01-01

Full Text Available We introduce an extensible software toolbox, xSPDE, for solving ordinary and partial stochastic differential equations. The toolbox makes extensive use of vector and parallel methods. Inputs are exceptionally simple, to reduce the learning curve, with default options for all of the many input parameters. The code calculates functional means, correlations and spectra, checks for errors in both time-step and sampling, and provides several choices of algorithm. Most aspects of the code, including the numerical algorithm, have a modular functional design to allow user modifications.

Development of Stepping Endurance Test Plan on CRDM of a Research Reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, DongHyun; Kim, Hyeonil; Park, Suki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Various types of the irradiation targets can be loaded and unloaded during power operation, according to the purpose of research reactor utilization. And their reactivity worth varies as well. The insertion rate of reactivity is dependent to reactivity worth of targets, travel length during loading or unloading and transfer device speed. Due to the reactivity transition during loading and unloading, neutron power is changed and reaches an action point of the reactor regulating system. Based on the measured neutron rate of change, reactor power control system controls the power with its own algorithm. It generates the signals and transmits these to the CRDM for motor driving. Stepping motors on the CRDM move the control rods with step signals. The process repeats until power is stabilized. Accordingly, the stepping behaviours of CRDM should be modelled upon an understanding of the control process and reactor responses. Methodology for a stepping endurance test plan on the CRDM of a research reactor is developed since CRDM endurance is very important for reactor controller and should be ensured for a certain period of time throughout the life of a research reactor. Therefore, it is expected to provide a reasonable stepping test plan. In the future, the simulation will be performed with specific design values.

Fabrication of ITO-rGO/Ag NPs nanocomposite by two-step chronoamperometry electrodeposition and its characterization as SERS substrate

Energy Technology Data Exchange (ETDEWEB)

Wang, Rong [Chemistry and Chemical Engineering College, Chongqing University, Shapingba, Chongqing 400044 (China); Key Disciplines Lab of Novel Micro-Nano Devices and System Technology, and School of Optoelectronics Engineering, Chongqing University, Shapingba, Chongqing 400044 (China); Analytical and Testing Center, Sichuan University of Science & Engineering, Zigong, Sichuan 643000 (China); Xu, Yi [Chemistry and Chemical Engineering College, Chongqing University, Shapingba, Chongqing 400044 (China); Key Disciplines Lab of Novel Micro-Nano Devices and System Technology, and School of Optoelectronics Engineering, Chongqing University, Shapingba, Chongqing 400044 (China); Wang, Chunyan [Key Disciplines Lab of Novel Micro-Nano Devices and System Technology, and School of Optoelectronics Engineering, Chongqing University, Shapingba, Chongqing 400044 (China); School of Optoelectronic Engineering, Chongqing University, Shapingba, Chongqing 400044 (China); Zhao, Huazhou; Wang, Renjie; Liao, Xin [Chemistry and Chemical Engineering College, Chongqing University, Shapingba, Chongqing 400044 (China); Key Disciplines Lab of Novel Micro-Nano Devices and System Technology, and School of Optoelectronics Engineering, Chongqing University, Shapingba, Chongqing 400044 (China); Chen, Li; Chen, Gang [Key Disciplines Lab of Novel Micro-Nano Devices and System Technology, and School of Optoelectronics Engineering, Chongqing University, Shapingba, Chongqing 400044 (China); School of Optoelectronic Engineering, Chongqing University, Shapingba, Chongqing 400044 (China)

2015-09-15

Highlights: • A novel structure of ITO-rGO/Ag NPs substrate was developed for SERS application. • Two-step chronoamperometry deposition method was used to prepare SERS substrate. • The SERS substrate had high SERS activity, good uniformity and reproducibility. - Abstract: A novel composite structure of reduced graphene oxide (rGO)–Ag nanoparticles (Ag NPs) nanocomposite, which was integrated on the indium tin oxide (ITO) glass by a facile and rapid two-step chronoamperometry electrodeposition route, was proposed and developed in this paper. SERS-activity of the rGO/Ag NPs nanocomposite was mainly affected by the structure and size of the fabricated rGO/Ag NPs nanocomposite. In the experiments, the operational conditions of electrodeposition process were studied in details. The electrodeposited time was the important controllable factor, which decided the particle size and surface coverage of the deposited Ag NPs on ITO glass. Under the optimized conditions, the detection limit for rhodamine6G (R6G) was as low as 10{sup −11} M and the Raman enhancement factor was as large as 5.9 × 10{sup 8}, which was 24 times higher than that for the ITO–Ag NPs substrate. Apart from this higher enhancement effect, it was also illustrated that extremely good uniformity and reproducibility with low standard deviation could be obtained by the prepared ITO-rGO/Ag NPs nanocomposite for SRES detection.

Stabilization of a three-dimensional limit cycle walking model through step-to-step ankle control.

Science.gov (United States)

Kim, Myunghee; Collins, Steven H

2013-06-01

Unilateral, below-knee amputation is associated with an increased risk of falls, which may be partially related to a loss of active ankle control. If ankle control can contribute significantly to maintaining balance, even in the presence of active foot placement, this might provide an opportunity to improve balance using robotic ankle-foot prostheses. We investigated ankle- and hip-based walking stabilization methods in a three-dimensional model of human gait that included ankle plantarflexion, ankle inversion-eversion, hip flexion-extension, and hip ad/abduction. We generated discrete feedback control laws (linear quadratic regulators) that altered nominal actuation parameters once per step. We used ankle push-off, lateral ankle stiffness and damping, fore-aft foot placement, lateral foot placement, or all of these as control inputs. We modeled environmental disturbances as random, bounded, unexpected changes in floor height, and defined balance performance as the maximum allowable disturbance value for which the model walked 500 steps without falling. Nominal walking motions were unstable, but were stabilized by all of the step-to-step control laws we tested. Surprisingly, step-by-step modulation of ankle push-off alone led to better balance performance (3.2% leg length) than lateral foot placement (1.2% leg length) for these control laws. These results suggest that appropriate control of robotic ankle-foot prosthesis push-off could make balancing during walking easier for individuals with amputation.

The effect of fish oil on two-step tuberculin test in hospitalized patients: A randomized controlled trial

Directory of Open Access Journals (Sweden)

N. Arfa

2018-02-01

Full Text Available Background: According to national tuberculosis control guide, two-step tuberculin skin test (TST should be done in the elderly, if the initial test is negative. However, it raises questions about the usefulness of this approach. Objective: This study aimed to explore the effects of fish oil supplements on the two-step tuberculin test in hospitalized patients. Methods: In this randomized controlled clinical trial, 128 patients randomly allocated to control group (receiving placebo, n=64 and treatment group (receiving fish oil supplements, n=64 during 2016. Fish oil supplement group was treated with 2 g daily for 4 consecutive days. The outcome was considered a change in 2 sequential TST induration sizes. Significant increase in the size of the secondary induration compared to primary was considered 6 mm or more. Findings: There was significant difference between primary and secondary indurations of two groups (higher in treatment group (P=0.04. According to the results of analysis of variance and correlation tests, two effective factors were identified: initial induration and residence location (P=0.014 and P=0.002, respectively. In both groups, no clinically significant increase in the size of induration was observed. Conclusion: It seems that the number of cases considered as infected with tuberculosis does not increase with two- rather than one-step tuberculin skin test. Also, the short-term administration of fish oil supplements does not change this result.

Distributed temperature sensors development using an stepped-helical ultrasonic waveguide

Science.gov (United States)

Periyannan, Suresh; Rajagopal, Prabhu; Balasubramaniam, Krishnan

2018-04-01

This paper presents the design and development of the distributed ultrasonic waveguide temperature sensors using some stepped-helical structures. Distributed sensing has several applications in various industries (oil, glass, steel) for measurement of physical parameters such as level, temperature, viscosity, etc. This waveguide incorporates a special notch or bend for obtaining ultrasonic wave reflections from the desired locations (Gage-lengths) where local measurements are desired. In this paper, a multi-location measurement wave-guide, with a measurement capability of 18 locations in a single wire, has been fabricated. The distribution of these sensors is both in the axial as well as radial directions using a stepped-helical spring configuration. Also, different high temperature materials have been chosen for the wave-guide. Both lower order axi-symmetric guided ultrasonic modes (L(0,1) and T(0,1)) were employed. These wave modes were generated/received (pulse-echo approach) using conventional longitudinal and shear transducers, respectively. Also, both the wave modes were simultaneously generated/received and compared using shear transducer for developing the distributed helical wave-guide sensors. The effect of dispersion of the wave modes due to curvature effects will also be discussed.

Linear lesions may assist early diagnosis of neuromyelitis optica and longitudinally extensive transverse myelitis, two subtypes of NMOSD.

Science.gov (United States)

Cai, Wei; Tan, Sha; Zhang, Lei; Shan, Yilong; Wang, Yanqiang; Lin, Yinyao; Zhou, Fangjing; Zhang, Bingjun; Chen, Xiaoyu; Zhou, Li; Wang, Yuge; Huang, Xuehong; Men, Xuejiao; Li, Haiyan; Qiu, Wei; Hu, Xueqiang; Lu, Zhengqi

2016-01-15

To investigate the relationship between linear lesions (LL) and the development of longitudinally extensive spinal cord lesions (LESCL) in Chinese patients with neuromyelitis optica or longitudinally extensive transverse myelitis. The clinical records of 143 patients with these conditions were reviewed. Forty-one patients with LL were divided into three groups according to the order of appearance of LL and LESCL (simultaneously [n=10], LL first [n=26], or LESCL first [n=5]). The remaining 102 patients without LL were used as a control group. Patients who developed LL first demonstrated a lower annualized relapse rate than those in the simultaneous group (1.00 [0.23-10.00] vs. 4.38 [0.60-6.67], p=0.017) and the control group (1.00 [0.23-10.00] vs. 2.00 [0.24-10.00], p=0.007). Among all patients with LL, there were significantly more who developed them before LESCL than those who developed them after LESCL (poptica and longitudinally extensive transverse myelitis. Copyright © 2015 Elsevier B.V. All rights reserved.

Compiling the parallel programming language NestStep to the CELL processor

OpenAIRE

Holm, Magnus

2010-01-01

The goal of this project is to create a source-to-source compiler which will translate NestStep code to C code. The compiler's job is to replace NestStep constructs with a series of function calls to the NestStep runtime system. NestStep is a parallel programming language extension based on the BSP model. It adds constructs for parallel programming on top of an imperative programming language. For this project, only constructs extending the C language are relevant. The output code will compil...

Superthermostability of nanoscale TIC-reinforced copper alloys manufactured by a two-step ball-milling process

Science.gov (United States)

Wang, Fenglin; Li, Yunping; Xu, Xiandong; Koizumi, Yuichiro; Yamanaka, Kenta; Bian, Huakang; Chiba, Akihiko

2015-12-01

A Cu-TiC alloy, with nanoscale TiC particles highly dispersed in the submicron-grained Cu matrix, was manufactured by a self-developed two-step ball-milling process on Cu, Ti and C powders. The thermostability of the composite was evaluated by high-temperature isothermal annealing treatments, with temperatures ranging from 727 to 1273 K. The semicoherent nanoscale TiC particles with Cu matrix, mainly located along the grain boundaries, were found to exhibit the promising trait of blocking grain boundary migrations, which leads to a super-stabilized microstructures up to approximately the melting point of copper (1223 K). Furthermore, the Cu-TiC alloys after annealing at 1323 K showed a slight decrease in Vickers hardness as well as the duplex microstructure due to selective grain growth, which were discussed in terms of hardness contributions from various mechanisms.

Issues in measure-preserving three dimensional flow integrators: Self-adjointness, reversibility, and non-uniform time stepping

International Nuclear Information System (INIS)

Finn, John M.

2015-01-01

Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a “special divergence-free” (SDF) property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. We also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Feng and Shang [Numer. Math. 71, 451 (1995)], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Richardson and Finn [Plasma Phys. Controlled Fusion 54, 014004 (2012

Two types of lateral extension in juvenile nasopharyngeal angiofibroma: diagnostic and therapeutic management.

Science.gov (United States)

Szymańska, Anna; Szymański, Marcin; Czekajska-Chehab, Elżbieta; Szczerbo-Trojanowska, Małgorzata

2015-01-01

Juvenile nasopharyngeal angiofibroma is a benign, locally aggressive nasopharyngeal tumor. Apart from anterior lateral extension to the pterygopalatine fossa, it may spread laterally posterior to the pterygoid process, showing posterior lateral growth pattern, which is less common and more difficult to identify during surgery. We analyzed the routes of lateral spread, modalities useful in its diagnosis, the incidence of lateral extension and its influence on outcomes of surgical treatment. The records of 37 patients with laterally extending JNA treated at our institution between 1987 and 2011 were retrospectively evaluated. Computed tomography was performed in all patients and magnetic resonance imaging in 17 (46 %) patients. CT and MRI were evaluated to determine routes and extension of JNA lateral spread. Anterior lateral extension to the pterygopalatine fossa occurred in 36 (97 %) patients and further to the infratemporal fossa in 20 (54 %) patients. In 16 (43 %) cases posterior lateral spread was observed: posterior to the pterygoid process and/or between its plates. The recurrence rate was 29.7 % (11/37). The majority of residual lesions was located behind the pterygoid process (7/11). Recurrent disease occurred in 3/21 patients with anterior lateral extension, in 7/15 patients with both types of lateral extensions and in 1 patient with posterior lateral extension. JNA posterior lateral extension may spread behind the pterygoid process or between its plates. The recurrence rate in patients with anterior and/or posterior lateral extension is significantly higher than in patients with anterior lateral extension only. Both CT and MRI allow identification of the anterior and posterior lateral extensions.

Step-to-step reproducibility and asymmetry to study gait auto-optimization in healthy and cerebral palsied subjects.

Science.gov (United States)

Descatoire, A; Femery, V; Potdevin, F; Moretto, P

2009-05-01

The purpose of our study was to compare plantar pressure asymmetry and step-to-step reproducibility in both able-bodied persons and two groups of hemiplegics. The relevance of the research was to determine the efficiency of asymmetry and reproducibility as indexes for diagnosis and rehabilitation processes. This study comprised 31 healthy young subjects and 20 young subjects suffering from cerebral palsy hemiplegia assigned to two groups of 10 subjects according to the severity of their musculoskeletal disorders. The peaks of plantar pressure and the time to peak pressure were recorded with an in-shoe measurement system. The intra-individual coefficient of variability was calculated to indicate the consistency of plantar pressure during walking and to define gait stability. The effect size was computed to quantify the asymmetry and measurements were conducted at eight footprint locations. Results indicated few differences in step-to-step reproducibility between the healthy group and the less spastic group while the most affected group showed a more asymmetrical and unstable gait. From the concept of self-optimisation and depending on the neuromotor disorders the organism could make priorities based on pain, mobility, stability or energy expenditure to develop the best gait auto-optimisation.

The Search for Extension: 7 Steps to Help People Find Research-Based Information on the Internet

Science.gov (United States)

Hill, Paul; Rader, Heidi B.; Hino, Jeff

2012-01-01

For Extension's unbiased, research-based content to be found by people searching the Internet, it needs to be organized in a way conducive to the ranking criteria of a search engine. With proper web design and search engine optimization techniques, Extension's content can be found, recognized, and properly indexed by search engines and…

Two-step freezing of hybridoma cells in 96-well microculture plates.

Science.gov (United States)

Pĕknicová, J; Kristofová, H

1985-01-01

Stabile hybridoma cells, colonies of hybridoma cells 14 days after fusion of immune spleen and myeloma cells, myeloma cells and fibroblasts cultured in 96-well microculture plates were frozen by the method of two-step freezing. The culture medium was aspirated, and 50 microliter of the medium containing a cryoprotectant (5% dimethyl sulphoxide) was added for 10 min at room temperature. The plates were put into microtene bags, placed at -25 degrees C in a freezer for 30 min and then stored at -100 degrees C in liquid nitrogen vapour. Plates with cells were thawed rapidly in a 50 degree C water bath. After thawing the hybrid cells were viable and continued to produce the specific antibody.

Application of Displacement Height and Surface Roughness Length to Determination Boundary Layer Development Length over Stepped Spillway

Directory of Open Access Journals (Sweden)

Xiangju Cheng

2014-12-01

Full Text Available One of the most uncertain parameters in stepped spillway design is the length (from the crest of boundary layer development. The normal velocity profiles responding to the steps as bed roughness are investigated in the developing non-aerated flow region. A detailed analysis of the logarithmic vertical velocity profiles on stepped spillways is conducted through experimental data to verify the computational code and numerical experiments to expand the data available. To determine development length, the hydraulic roughness and displacement thickness, along with the shear velocity, are needed. This includes determining displacement height d and surface roughness length z0 and the relationship of d and z0 to the step geometry. The results show that the hydraulic roughness height ks is the primary factor on which d and z0 depend. In different step height, step width, discharge and intake Froude number, the relations d/ks = 0.22–0.27, z0/ks = 0.06–0.1 and d/z0 = 2.2–4 result in a good estimate. Using the computational code and numerical experiments, air inception will occur over stepped spillway flow as long as the Bauer-defined boundary layer thickness is between 0.72 and 0.79.

Surface Activity of Sulfactin Recovered and Purified from Fermentation Broth Using a Two-Step Ultrafiltration (UF) Process

International Nuclear Information System (INIS)

Mohd Hafez Mohd Isa; Frazier, A.R.; Jauregi, P.

2011-01-01

B. subtilis under certain types of media and fermentation conditions can produce surfactant, a bio surfactant which belongs to the lipo peptide class. Surfactant has exceptional surfactant activity, and exhibits some interesting biological characteristics such as antibacterial activity, anti tumoral activity against ascites carcinoma cells, and a hypercholesterolaemia activity that inhibits cAMP phosphodiesterase, as well as having anti-HIV properties. A cost effective recovery and purification of surfactant from fermentation broth using a two-step ultrafiltration (UF) process has been developed in order to reduce the cost of surfactant production. In this study, competitive adsorption of surfactant and proteins at the air-water interface was studied using surface pressure measurements. Small volumes of bovine serum albumin (BSA) and β-casein solutions were added to the air-water interface on a Langmuir trough and allowed to stabilise before the addition of surfactant to the sub phase. Contrasting interfacial behaviour of proteins was observed with β-casein showing faster initial adsorption compared to BSA. On introduction of surfactant both proteins were displaced but a longer time were taken to displace β-casein. Overall the results showed surfactant were highly surface-active by forming a β-sheet structure at the air-water interface after reaching its critical micelle concentration (CMC) and were effective in removing both protein films, which can be explained following the orogenic mechanism. Results showed that the two-step UF process was effective to achieve high purity and fully functional surfactant. (author)

Conventional and two step sintering of PZT-PCN ceramics

Science.gov (United States)

Keshavarzi, Mostafa; Rahmani, Hooman; Nemati, Ali; Hashemi, Mahdieh

2018-02-01

In this study, PZT-PCN ceramic was made via sol-gel seeding method and effects of conventional sintering (CS) as well as two-step sintering (TSS) were investigated on microstructure, phase formation, density, dielectric and piezoelectric properties. First, high quality powder was achieved by seeding method in which the mixture of Co3O4 and Nb2O5 powder was added to the prepared PZT sol to form PZT-PCN gel. After drying and calcination, pyrochlore free PZT-PCN powder was synthesized. Second, CS and TSS were applied to achieve dense ceramic. The optimum temperature used for 2 h of conventional sintering was obtained at 1150 °C; finally, undesired ZrO2 phase formed in CS procedure was removed successfully with TSS procedure and dielectric and piezoelectric properties were improved compared to the CS procedure. The best electrical properties obtained for the sample sintered by TSS in the initial temperature of T 1 = 1200 °C and secondary temperature of T 2 = 1000 °C for 12 h.

A simple two-step purification procedure for the iC3b binding collectin conglutinin

DEFF Research Database (Denmark)

Krogh-Meibom, Thomas; Ingvartsen, Klaus Lønne; Tornoe, Ida

2010-01-01

Bovine conglutinin is a serum protein involved in innate immunity. It binds calcium dependently to iC3b, a product of the complement component C3 deposited on cell surfaces, immune complexes or artificial surfaces after complement activation. We here present a simple and efficient two-step proced...

A Novel Walking Detection and Step Counting Algorithm Using Unconstrained Smartphones.

Science.gov (United States)

Kang, Xiaomin; Huang, Baoqi; Qi, Guodong

2018-01-19

Recently, with the development of artificial intelligence technologies and the popularity of mobile devices, walking detection and step counting have gained much attention since they play an important role in the fields of equipment positioning, saving energy, behavior recognition, etc. In this paper, a novel algorithm is proposed to simultaneously detect walking motion and count steps through unconstrained smartphones in the sense that the smartphone placement is not only arbitrary but also alterable. On account of the periodicity of the walking motion and sensitivity of gyroscopes, the proposed algorithm extracts the frequency domain features from three-dimensional (3D) angular velocities of a smartphone through FFT (fast Fourier transform) and identifies whether its holder is walking or not irrespective of its placement. Furthermore, the corresponding step frequency is recursively updated to evaluate the step count in real time. Extensive experiments are conducted by involving eight subjects and different walking scenarios in a realistic environment. It is shown that the proposed method achieves the precision of 93.76 % and recall of 93.65 % for walking detection, and its overall performance is significantly better than other well-known methods. Moreover, the accuracy of step counting by the proposed method is 95.74 % , and is better than both of the several well-known counterparts and commercial products.

Effect of One-Step and Multi-Steps Polishing System on Enamel Roughness

Directory of Open Access Journals (Sweden)

Cynthia Sumali

2013-07-01

Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 The final procedures of orthodontic treatment are bracket debonding and cleaning the remaining adhesive. Multi-step polishing system is the most common method used. The disadvantage of that system is long working time, because of the stages that should be done. Therefore, dental material manufacturer make an improvement to the system, to reduce several stages into one stage only. This new system is known as one-step polishing system. Objective: To compare the effect of one-step and multi-step polishing system on enamel roughness after orthodontic bracket debonding. Methods: Randomized control trial was conducted included twenty-eight maxillary premolar randomized into two polishing system; one-step OptraPol (Ivoclar, Vivadent and multi-step AstroPol (Ivoclar, Vivadent. After bracket debonding, the remaining adhesive on each group was cleaned by subjective polishing system for ninety seconds using low speed handpiece. The enamel roughness was subjected to profilometer, registering two roughness parameters (Ra, Rz. Independent t-test was used to analyze the mean score of enamel roughness in each group. Results: There was no significant difference of enamel roughness between one-step and multi-step polishing system (p>0.005. Conclusion: One-step polishing system can produce a similar enamel roughness to multi-step polishing system after bracket debonding and adhesive cleaning.DOI: 10.14693/jdi.v19i3.136

Effects of acute alcohol intoxication on automated processing: evidence from the double-step paradigm.

Science.gov (United States)

Vorstius, Christian; Radach, Ralph; Lang, Alan R

2012-02-01

Reflexive and voluntary levels of processing have been studied extensively with respect to possible impairments due to alcohol intoxication. This study examined alcohol effects at the 'automated' level of processing essential to many complex visual processing tasks (e.g., reading, visual search) that involve ongoing modifications or reprogramming of well-practiced routines. Data from 30 participants (16 male) were collected in two counterbalanced sessions (alcohol vs. no-alcohol control; mean breath alcohol concentration = 68 mg/dL vs. 0 mg/dL). Eye movements were recorded during a double-step task where 75% of trials involved two target stimuli in rapid succession (inter-stimulus interval [ISI]=40, 70, or 100 ms) so that they could elicit two distinct saccades or eye movements (double steps). On 25% of trials a single target appeared. Results indicated that saccade latencies were longer under alcohol. In addition, the proportion of single-step responses and the mean saccade amplitude (length) of primary saccades decreased significantly with increasing ISI. The key novel finding, however, was that the reprogramming time needed to cancel the first saccade and adjust saccade amplitude was extended significantly by alcohol. The additional time made available by prolonged latencies due to alcohol was not utilized by the saccade programming system to decrease the number of two-step responses. These results represent the first demonstration of specific alcohol-induced programming deficits at the automated level of oculomotor processing.

MANAGEMENT OF RENEWABLE ENERGY AND REGIONAL DEVELOPMENT: EUROPEAN EXPERIENCES AND STEPS FORWARD

OpenAIRE

Andreea Ileana Zamfir

2011-01-01

The issues of the renewable energy and regional development have become major priorities for public policymakers across the globe. Therefore, this study explores some European experiences and steps forward in the field of the management of renewable energy and regional development. Firstly, an overview of renewable energy issues in European regions is revealed, and secondly, some measures and actions for managing regional development of renewable energy in Romania taking into account the fina...

Facile fabrication of a silicon nanowire sensor by two size reduction steps for detection of alpha-fetoprotein biomarker of liver cancer

International Nuclear Information System (INIS)

Pham, Van Binh; Pham, Xuan ThanhTung; Phan, Thanh Nhat Khoa; Le, Thi Thanh Tuyen; Dang, Mau Chien

2015-01-01

We present a facile technique that only uses conventional micro-techniques and two size-reduction steps to fabricate wafer-scale silicon nanowire (SiNW) with widths of 200 nm. Initially, conventional lithography was used to pattern SiNW with 2 μm width. Then the nanowire width was decreased to 200 nm by two size-reduction steps with isotropic wet etching. The fabricated SiNW was further investigated when used with nanowire field-effect sensors. The electrical characteristics of the fabricated SiNW devices were characterized and pH sensitivity was investigated. Then a simple and effective surface modification process was carried out to modify SiNW for subsequent binding of a desired receptor. The complete SiNW-based biosensor was then used to detect alpha-fetoprotein (AFP), one of the medically approved biomarkers for liver cancer diagnosis. Electrical measurements showed that the developed SiNW biosensor could detect AFP with concentrations of about 100 ng mL"−"1. This concentration is lower than the necessary AFP concentration for liver cancer diagnosis. (paper)

Facile fabrication of a silicon nanowire sensor by two size reduction steps for detection of alpha-fetoprotein biomarker of liver cancer

Science.gov (United States)

Binh Pham, Van; ThanhTung Pham, Xuan; Nhat Khoa Phan, Thanh; Thanh Tuyen Le, Thi; Chien Dang, Mau

2015-12-01

We present a facile technique that only uses conventional micro-techniques and two size-reduction steps to fabricate wafer-scale silicon nanowire (SiNW) with widths of 200 nm. Initially, conventional lithography was used to pattern SiNW with 2 μm width. Then the nanowire width was decreased to 200 nm by two size-reduction steps with isotropic wet etching. The fabricated SiNW was further investigated when used with nanowire field-effect sensors. The electrical characteristics of the fabricated SiNW devices were characterized and pH sensitivity was investigated. Then a simple and effective surface modification process was carried out to modify SiNW for subsequent binding of a desired receptor. The complete SiNW-based biosensor was then used to detect alpha-fetoprotein (AFP), one of the medically approved biomarkers for liver cancer diagnosis. Electrical measurements showed that the developed SiNW biosensor could detect AFP with concentrations of about 100 ng mL-1. This concentration is lower than the necessary AFP concentration for liver cancer diagnosis.

Semi-Automated Hydrophobic Interaction Chromatography Column Scouting Used in the Two-Step Purification of Recombinant Green Fluorescent Protein

Science.gov (United States)

Murphy, Patrick J. M.

2014-01-01

Background Hydrophobic interaction chromatography (HIC) most commonly requires experimental determination (i.e., scouting) in order to select an optimal chromatographic medium for purifying a given target protein. Neither a two-step purification of untagged green fluorescent protein (GFP) from crude bacterial lysate using sequential HIC and size exclusion chromatography (SEC), nor HIC column scouting elution profiles of GFP, have been previously reported. Methods and Results Bacterial lysate expressing recombinant GFP was sequentially adsorbed to commercially available HIC columns containing butyl, octyl, and phenyl-based HIC ligands coupled to matrices of varying bead size. The lysate was fractionated using a linear ammonium phosphate salt gradient at constant pH. Collected HIC eluate fractions containing retained GFP were then pooled and further purified using high-resolution preparative SEC. Significant differences in presumptive GFP elution profiles were observed using in-line absorption spectrophotometry (A395) and post-run fluorimetry. SDS-PAGE and western blot demonstrated that fluorometric detection was the more accurate indicator of GFP elution in both HIC and SEC purification steps. Comparison of composite HIC column scouting data indicated that a phenyl ligand coupled to a 34 µm matrix produced the highest degree of target protein capture and separation. Conclusions Conducting two-step protein purification using the preferred HIC medium followed by SEC resulted in a final, concentrated product with >98% protein purity. In-line absorbance spectrophotometry was not as precise of an indicator of GFP elution as post-run fluorimetry. These findings demonstrate the importance of utilizing a combination of detection methods when evaluating purification strategies. GFP is a well-characterized model protein, used heavily in educational settings and by researchers with limited protein purification experience, and the data and strategies presented here may aid in

Design and Development of a Step Climbing Wheeled Robot

Directory of Open Access Journals (Sweden)

Srijan BHATTACHARYA

2009-08-01

Full Text Available This paper presents a design of Step Climbing Robot that can move in uneven environment and traverse a slope or staircase. The condition imposed on this new system of robot is that it will move only in linear fashion, which will reduce the demands on the physical complexity of the robot unit. A summary of the current state of research in the field of mobile robots as it relates to robot stair climbing and moving in uneven surfaces. The architecture of the robot is developed and compared with the previous design.

Enhancement of the photo conversion efficiencies in Cu(In,Ga)(Se,S){sub 2} solar cells fabricated by two-step sulfurization process

Energy Technology Data Exchange (ETDEWEB)

Yang, JungYup; Nam, Junggyu; Kim, Dongseop; Lee, Dongho, E-mail: dhlee0333@gmail.com, E-mail: ddang@korea.ac.kr [Photovoltaic Development Team, Energy Storage Business Division, Samsung SDI, Cheonan-si 331-300 (Korea, Republic of); Kim, GeeYeong; Jo, William [Department of Physics and New and Renewable Energy Research Center, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Kang, Yoonmook, E-mail: dhlee0333@gmail.com, E-mail: ddang@korea.ac.kr [KUKIST Green School, Graduate School of Energy and Environment, Korea University, Seoul 136-701 (Korea, Republic of)

2015-11-09

Cu(In,Ga)(Se,S){sub 2} (CIGSS) absorber layers were fabricated by using a modified two-stage sputter and a sequential selenization/sulfurization method, and the sulfurization process is changed from one-step to two-step. The two-step sulfurization was controlled with two different H{sub 2}S gas concentrations during the sulfurization treatment. This two-step process yielded remarkable improvements in the efficiency (+0.7%), open circuit voltage (+14 mV), short circuit current (+0.23 mA/cm{sup 2}), and fill factor (+0.21%) of a CIGSS device with 30 × 30 cm{sup 2} in size, owing to the good passivation at the grain boundary surface, uniform material composition among the grain boundaries, and modified depth profile of Ga and S. The deterioration of the P/N junction quality was prevented by the optimized S content in the CIGSS absorber layer. The effects of the passivation quality at the grain boundary surface, the material uniformity, the compositional depth profiles, the microstructure, and the electrical characteristics were examined by Kelvin probe force microscopy, X-ray diffraction, secondary ion mass spectrometry, scanning electron microscopy, and current-voltage curves, respectively. The two-step sulfurization process is experimentally found to be useful for obtaining good surface conditions and, enhancing the efficiency, for the mass production of large CIGSS modules.

An implicit second order numerical method for two-fluid models

International Nuclear Information System (INIS)

Toumi, I.

1995-01-01

We present an implicit upwind numerical method for a six equation two-fluid model based on a linearized Riemann solver. The construction of this approximate Riemann solver uses an extension of Roe's scheme. Extension to second order accurate method is achieved using a piecewise linear approximation of the solution and a slope limiter method. For advancing in time, a linearized implicit integrating step is used. In practice this new numerical method has proved to be stable and capable of generating accurate non-oscillating solutions for two-phase flow calculations. The scheme was applied both to shock tube problems and to standard tests for two-fluid codes. (author)

Development of an aging evaluation and life extension program for the Advanced Test Reactor

International Nuclear Information System (INIS)

Dwight, J.E. Jr.

1988-01-01

A life extension program has been developed for the US Department of Energy's Advanced Test Reactor. The program is an adaptation of life extension pilot programs at the Surry Unit 1 and Monticello generating stations and is being completed in three phases. In Phase 1, the critical plant components were identified. In Phase 2, existing lifetime analyses and support data for the critical components were reviewed. The results from the review give a preliminary indication that an overall plant lifetime in excess of forty years is feasible. In Phase 3, now in progress, detailed evaluations for component life extensions are being performed. 2 refs., 2 figs., 1 tab

The eXtensible ontology development (XOD) principles and tool implementation to support ontology interoperability.

Science.gov (United States)

He, Yongqun; Xiang, Zuoshuang; Zheng, Jie; Lin, Yu; Overton, James A; Ong, Edison

2018-01-12

Ontologies are critical to data/metadata and knowledge standardization, sharing, and analysis. With hundreds of biological and biomedical ontologies developed, it has become critical to ensure ontology interoperability and the usage of interoperable ontologies for standardized data representation and integration. The suite of web-based Ontoanimal tools (e.g., Ontofox, Ontorat, and Ontobee) support different aspects of extensible ontology development. By summarizing the common features of Ontoanimal and other similar tools, we identified and proposed an "eXtensible Ontology Development" (XOD) strategy and its associated four principles. These XOD principles reuse existing terms and semantic relations from reliable ontologies, develop and apply well-established ontology design patterns (ODPs), and involve community efforts to support new ontology development, promoting standardized and interoperable data and knowledge representation and integration. The adoption of the XOD strategy, together with robust XOD tool development, will greatly support ontology interoperability and robust ontology applications to support data to be Findable, Accessible, Interoperable and Reusable (i.e., FAIR).

The ATP hydrolysis and phosphate release steps control the time course of force development in rabbit skeletal muscle.

Science.gov (United States)

Sleep, John; Irving, Malcolm; Burton, Kevin

2005-03-15

The time course of isometric force development following photolytic release of ATP in the presence of Ca(2+) was characterized in single skinned fibres from rabbit psoas muscle. Pre-photolysis force was minimized using apyrase to remove contaminating ATP and ADP. After the initial force rise induced by ATP release, a rapid shortening ramp terminated by a step stretch to the original length was imposed, and the time course of the subsequent force redevelopment was again characterized. Force development after ATP release was accurately described by a lag phase followed by one or two exponential components. At 20 degrees C, the lag was 5.6 +/- 0.4 ms (s.e.m., n = 11), and the force rise was well fitted by a single exponential with rate constant 71 +/- 4 s(-1). Force redevelopment after shortening-restretch began from about half the plateau force level, and its single-exponential rate constant was 68 +/- 3 s(-1), very similar to that following ATP release. When fibres were activated by the addition of Ca(2+) in ATP-containing solution, force developed more slowly, and the rate constant for force redevelopment following shortening-restretch reached a maximum value of 38 +/- 4 s(-1) (n = 6) after about 6 s of activation. This lower value may be associated with progressive sarcomere disorder at elevated temperature. Force development following ATP release was much slower at 5 degrees C than at 20 degrees C. The rate constant of a single-exponential fit to the force rise was 4.3 +/- 0.4 s(-1) (n = 22), and this was again similar to that after shortening-restretch in the same activation at this temperature, 3.8 +/- 0.2 s(-1). We conclude that force development after ATP release and shortening-restretch are controlled by the same steps in the actin-myosin ATPase cycle. The present results and much previous work on mechanical-chemical coupling in muscle can be explained by a kinetic scheme in which force is generated by a rapid conformational change bracketed by two

Effects of V{sub 2}O{sub 5} addition on NiZn ferrite synthesized using two-step sintering process

Energy Technology Data Exchange (ETDEWEB)

Hu Jun [College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Shi Gang; Ni Zheming; Zheng Li [College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Chen Aimin, E-mail: hjzjut@zjut.edu.cn [College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)

2012-06-15

The combined influence of a two-step sintering (TSS) process and addition of V{sub 2}O{sub 5} on the microstructure and magnetic properties of NiZn ferrite was investigated. As comparison, samples prepared by the conventional single-step sintering (SSS) procedure were also studied. It was found that with 0.3 wt% V{sub 2}O{sub 5} additive, the sample sintered by the two-step sintering process at a high temperature of 1250 Degree-Sign C for 30 min and a lower temperature of 1180 Degree-Sign C for 3 h exhibited more homogeneous microstructure and higher permeability with a high Q-factor. The results showed that the TSS method with suitable additive brought positive improvement of the microstructure and magnetic properties of NiZn ferrite.

Characteristics of MAO coating obtained on ZK60 Mg alloy under two and three steps voltage-increasing modes in dual electrolyte

Science.gov (United States)

Yang, Jun; Wang, Ze-Xin; Lu, Sheng; Lv, Wei-gang; Jiang, Xi-zhi; Sun, Lei

2017-03-01

The micro-arc oxidation process was conducted on ZK60 Mg alloy under two and three steps voltage-increasing modes by DC pulse electrical source. The effect of each mode on current-time responses during MAO process and the coating characteristic were analysed and discussed systematically. The microstructure, thickness and corrosion resistance of MAO coatings were evaluated by scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), microscope with super-depth of field and electrochemical impedance spectroscopy (EIS). The results indicate that two and three steps voltage-increasing modes can improve weak spark discharges with insufficient breakdown strength in later period during the MAO process. Due to higher value of voltage and voltage increment, the coating with maximum thickness of about 20.20μm formed under two steps voltage-increasing mode shows the best corrosion resistance. In addition, the coating fabricated under three steps voltage-increasing mode shows a smoother coating with better corrosion resistance due to the lower amplitude of voltage-increasing.

STEPS: A NARRATIVE ACCOUNT OF A GABAPENTIN SEEDING TRIAL

Science.gov (United States)

Krumholz, Samuel D.; Egilman, David S.; Ross, Joseph S.

2012-01-01

Background Seeding trials, clinical studies conducted by pharmaceutical companies for marketing purposes, have rarely been described in detail. Methods We examined all documents relating to the clinical trial Study of Neurontin: Titrate to Effect, Profile of Safety (STEPS) produced during the Neurontin marketing, sales practices and product liability litigation, including company internal and external correspondence, reports, and presentations, as well as depositions elicited in legal proceedings of Harden Manufacturing v. Pfizer and Franklin v. Warner-Lambert, the majority of which were created between 1990 and 2009. Using a systematic search strategy, we identified and reviewed all documents related to the STEPS trial, in order to identify key themes related to the trial’s conduct and determine the extent of marketing involvement in its planning and implementation. Results Documents demonstrated that STEPS was a seeding trial posing as a legitimate scientific study. Documents consistently described the trial itself, not trial results, to be a marketing tactic in the company’s marketing plans. Documents demonstrated that several external sources questioned the validity of the study before execution, and that data quality during the study was often compromised. Furthermore, documents described company analyses examining the impact of participating as a STEPS investigator on rates and dosages of gabapentin prescribing, finding a positive association. None of these findings were reported in two published papers. Conclusions The STEPS trial was a seeding trial, used to promote gabapentin and increase prescribing among investigators, and marketing was extensively involved in its planning and implementation. PMID:21709111

Two-step excitation structure changes of luminescence centers and strong tunable blue emission on surface of silica nanospheres

Energy Technology Data Exchange (ETDEWEB)

Yang, Lei, E-mail: nanoyang@qq.com; Jiang, Zhongcheng; Dong, Jiazhang; Zhang, Liuqian [Hunan University, College of Materials Science and Engineering (China); Pan, Anlian, E-mail: anlian.pan@gmail.com; Zhuang, Xiujuan [Hunan University, Key Laboratory for Micro-Nano Physics and Technology of Hunan Province (China)

2015-10-15

We report a scheme for investigating two-step stimulated structure change of luminescence centers. Amorphous silica nanospheres with uniform diameter of 9–15 nm have been synthesized by Stöber method. Strong hydroxyl-related infrared-absorption band is observed in infrared spectrum. The surface hydroxyl groups exert great influence on the luminescent behavior of silica. They provide stable and intermediate energy states to accommodate excitation electrons. The existence of these surface states reduces the energy barrier of photochemical reactions, creating conditions for two-step excitation process. By carefully examining excitation and emission process, the nearest excitation band is absent in both optical absorption spectrum and excitation spectrum. This later generated state confirms the generation of new luminescence centers as well as the existence of photochemical reactions. Stimulated by different energies, two-step excitation process impels different photochemical reactions, prompting generation of different lattice defects on surface area of silica. Thereby, tunable luminescence is achieved. After thermal treatment, strong gap excitation band appears with the disappearance of strong surface excitation band. Strong blue luminescence also disappears. The research is significance to precise introducing structural defects and controlling position of luminescence peaks.

The importance of a two-step impression procedure for complete denture fabrication: a systematic review of the literature.

Science.gov (United States)

Regis, R R; Alves, C C S; Rocha, S S M; Negreiros, W A; Freitas-Pontes, K M

2016-10-01

The literature has questioned the real need for some clinical and laboratory procedures considered essential for achieving better results for complete denture fabrication. The aim of this study was to review the current literature concerning the relevance of a two-step impression procedure to achieve better clinical results in fabricating conventional complete dentures. Through an electronic search strategy of the PubMed/MEDLINE database, randomised controlled clinical trials which compared complete denture fabrication in adults in which one or two steps of impressions occurred were identified. The selections were made by three independent reviewers. Among the 540 titles initially identified, four studies (seven published papers) reporting on 257 patients evaluating aspects such as oral health-related quality of life, patient satisfaction with dentures in use, masticatory performance and chewing ability, denture quality, direct and indirect costs were considered eligible. The quality of included studies was assessed according to the Cochrane guidelines. The clinical studies considered for this review suggest that a two-step impression procedure may not be mandatory for the success of conventional complete denture fabrication regarding a variety of clinical aspects of denture quality and patients' perceptions of the treatment. © 2016 John Wiley & Sons Ltd.

A New Two-Step Approach for Hands-On Teaching of Gene Technology: Effects on Students' Activities During Experimentation in an Outreach Gene Technology Lab

Science.gov (United States)

Scharfenberg, Franz-Josef; Bogner, Franz X.

2011-08-01

Emphasis on improving higher level biology education continues. A new two-step approach to the experimental phases within an outreach gene technology lab, derived from cognitive load theory, is presented. We compared our approach using a quasi-experimental design with the conventional one-step mode. The difference consisted of additional focused discussions combined with students writing down their ideas (step one) prior to starting any experimental procedure (step two). We monitored students' activities during the experimental phases by continuously videotaping 20 work groups within each approach ( N = 131). Subsequent classification of students' activities yielded 10 categories (with well-fitting intra- and inter-observer scores with respect to reliability). Based on the students' individual time budgets, we evaluated students' roles during experimentation from their prevalent activities (by independently using two cluster analysis methods). Independently of the approach, two common clusters emerged, which we labeled as `all-rounders' and as `passive students', and two clusters specific to each approach: `observers' as well as `high-experimenters' were identified only within the one-step approach whereas under the two-step conditions `managers' and `scribes' were identified. Potential changes in group-leadership style during experimentation are discussed, and conclusions for optimizing science teaching are drawn.

Two-step estimation in ratio-of-mediator-probability weighted causal mediation analysis.

Science.gov (United States)

Bein, Edward; Deutsch, Jonah; Hong, Guanglei; Porter, Kristin E; Qin, Xu; Yang, Cheng

2018-04-15

This study investigates appropriate estimation of estimator variability in the context of causal mediation analysis that employs propensity score-based weighting. Such an analysis decomposes the total effect of a treatment on the outcome into an indirect effect transmitted through a focal mediator and a direct effect bypassing the mediator. Ratio-of-mediator-probability weighting estimates these causal effects by adjusting for the confounding impact of a large number of pretreatment covariates through propensity score-based weighting. In step 1, a propensity score model is estimated. In step 2, the causal effects of interest are estimated using weights derived from the prior step's regression coefficient estimates. Statistical inferences obtained from this 2-step estimation procedure are potentially problematic if the estimated standard errors of the causal effect estimates do not reflect the sampling uncertainty in the estimation of the weights. This study extends to ratio-of-mediator-probability weighting analysis a solution to the 2-step estimation problem by stacking the score functions from both steps. We derive the asymptotic variance-covariance matrix for the indirect effect and direct effect 2-step estimators, provide simulation results, and illustrate with an application study. Our simulation results indicate that the sampling uncertainty in the estimated weights should not be ignored. The standard error estimation using the stacking procedure offers a viable alternative to bootstrap standard error estimation. We discuss broad implications of this approach for causal analysis involving propensity score-based weighting. Copyright © 2018 John Wiley & Sons, Ltd.

Reduction of NOx in synthetic diesel exhaust via two-step plasma-catalysis treatment

International Nuclear Information System (INIS)

Tonkyn, R.G.; Barlow, S.E.; Hoard, John W.

2003-01-01

Significant reduction of NO x in synthetic light duty diesel exhaust has been achieved over a broad temperature window by combining atmospheric plasma with appropriate catalysts. The technique relies on the addition of hydrocarbon reductant prior to passing the simulated exhaust through a non-thermal plasma and a catalyst bed. The observed chemistry in the plasma includes conversion of NO to NO 2 as well as the partial oxidation of the hydrocarbon. The overall NO x reduction has a maximum of less than 80%, with this maximum obtained only at high-energy input into the plasma, high concentration of hydrocarbon reductant and low space velocity. We present data in this paper illustrating that a multiple-step treatment strategy, whereby two or more plasma-catalyst reactors are utilized in series, can increase the maximum NO x conversion obtainable. Alternatively, this technique can reduce the energy and/or hydrocarbon requirements for a fixed conversion efficiency. When propene is used as the reductant, the limiting reagent for the overall process is most likely acetaldehyde. The data suggest that acetaldehyde is formed in concert with NO oxidation to NO 2 in the plasma stage. The limited NO x reduction efficiency attained in a single step, even with excess energy, oxygen content and/or hydrocarbon-to-NO x ratio is well explained by this hypothesis, as is the effectiveness of the multiple-step treatment strategy. We present the data here illustrating the advantage of this approach under a wide variety of conditions

New examples of frobenius extensions

CERN Document Server

Kadison, Lars

1999-01-01

This volume is based on the author's lecture courses to algebraists at Munich and at G�teborg. He presents, for the first time in book form, a unified approach from the point of view of Frobenius algebras/extensions to diverse topics, such as Jones' subfactor theory, Hopf algebras and Hopf subalgebras, the Yang-Baxter Equation and 2-dimensional topological quantum field theories. Other Features: Initial steps toward a theory of noncommutative ring extensions. Self-contained sections on Azumaya algebras and strongly separable algebras. Applications and generalizations of Morita theory and Azumaya algebra due to Hirata and Sugano. Understanding the text requires no prior background in Frobenius algebras or Hopf algebras. An index and a thorough list of further references are included. There is an appendix giving a brief historical guide to the literature.

A two-parameter extension of classical nucleation theory

Science.gov (United States)

Lutsko, James F.; Durán-Olivencia, Miguel A.

2015-06-01

A two-variable stochastic model for diffusion-limited nucleation is developed using a formalism derived from fluctuating hydrodynamics. The model is a direct generalization of the standard classical nucleation theory (CNT). The nucleation rate and pathway are calculated in the weak-noise approximation and are shown to be in good agreement with direct numerical simulations for the weak-solution/strong-solution transition in globular proteins. We find that CNT underestimates the time needed for the formation of a critical cluster by two orders of magnitude and that this discrepancy is due to the more complex dynamics of the two variable model and not, as often is assumed, a result of errors in the estimation of the free energy barrier.

Two-dimensional nucleonics calculations for a ''FIRST STEP'' conceptual ICF reactor

International Nuclear Information System (INIS)

Davidson, J.W.; Battat, M.E.; Saylor, W.W.; Pendergrass, J.H.; Dudziak, D.J.

1985-01-01

A detailed two-dimensional nucleonic analysis has been performed for the FIRST STEP conceptual ICF reactor blanket design. The reactor concept incorporated in this design is a modified wetted-wall cavity with target illumination geometry left as a design variable. The 2-m radius spherical cavity is surrounded by a blanket containing lithium and 238 U as fertile species and also as energy multipliers. The blanket is configured as 0.6-m-thick cylindrical annuli containing modified LMFBR-type fuel elements with 0.5-m-thick fuel-bearing axial end plugs. Liquid lithium surrounds the inner blanket regions and serves as the coolant for both the blanket and the first wall. The two-dimensional analysis of the blanket performance was made using the 2-D discrete-ordinates code TRISM, and benchmarked with the 3-D Monte Carlo code MCNP. Integral responses including the tritium breeding ratio (TBR), plutonium breeding ratio (PUBR), and blanket energy multiplication were calculated for axial and radial blanket regions. Spatial distributions were calculated for steady-state rates of fission, neutron heating, prompt gamma-ray heating, and fuel breeding

Trap and corral: a two-step approach for constructing and constraining dynamic cell contact events in differentiating progenitor cell populations

International Nuclear Information System (INIS)

Chen, S; Patel, N; Schaffer, D; Maharbiz, M M

2011-01-01

Cells are constantly subjected to a host of external signals which can influence their state, phenotype and behavior. Mammalian cells are dependent on signals from surrounding cells to maintain viability, proliferate and coordinate their actions. During developmental and regenerative processes, these lateral signals between cells provide instructive cues informing stem cells how, when and where to differentiate. Moreover, differentiating cells often experience cell–cell contact events interspersed with bouts of motility, process extension and multi-cell agglomeration (Gage 2000 Science 287 1433–8) processes which are not easily recapitulated in existing cell capture devices. Here, we present a two-step process involving microwells to trap cells with high efficiency followed by the alignment of a PDMS mesh around the cells to corral them after the trapping. The microwells trap single cells and paired cells with up to 90% and 80% efficiencies, respectively. After seeding, the PDMS mesh is aligned with the seeded wells to create a 150 µm × 150 µm corral around each trap, allowing cells to interact in a larger arena. The corralling must be done in liquid after seeding because the seeding requires high cell densities to achieve near-full occupancy in the wells. Low-density seeding of the PDMS corrals alone can result in two cells being trapped in each well, but in those conditions, the two cells often engage in very little contact or none at all (and seeding obeys a non-desirable Poisson distribution). Interestingly, trapping cells in proximity and then corralling them elicits much higher contact times than simply seeding into corrals

Development of two-phase Flow Model, 'SOBOIL', for Sodium

International Nuclear Information System (INIS)

Hahn, Do Hee; Chang, Won Pyo; Kim, In Chul; Kwon, Young Min; Lee, Yong Bum

2000-03-01

The objective of this research is to develop a sodium two-phase flow analysis model, 'SOBOIL', for the assessment of the initial stage of the KALIMER HCDA (Hypotherical Core Disruptive Accident). The 'SOBOIL' is basically similar to the multi-bubble slug ejection model used in SAS2A[1]. When a bubble is formed within the liquid slug, the bubble fills the whole cross section of the coolant channel except for a film left on the cladding or on the structure. Up to nine bubbles, separated by the liquid slugs, are allowed in the channel at any time. Each liquid slug flow rate in the model is performed in 2 steps. In the first step, the preliminary flow rate in the liquid slug is calculated neglecting the effect of changes in the vapor bubble pressures over the time step. The temperature and pressure distributions, and interface velocity at the interface between the liquid slug and vapor bubble are also calculated during this process. The new vapor temperature and pressure are then determined from the balance between the net energy transferred into the vapor and the change of the vapor energy. The liquid flow is finally calculated considering the change of the vapor pressure over a time step and the calculation is repeated until specified elapsed time is met. Continuous effort, therefore, must be made on the examination and improvement for the model to become reliable. To this end, much interest must be concentrated in the relevant international collaborations for access to a reference model or test data for the verification

Applications and extensions of degradation modeling

International Nuclear Information System (INIS)

Hsu, F.; Subudhi, M.; Samanta, P.K.; Vesely, W.E.

1991-01-01

Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs

Applications and extensions of degradation modeling