Relating crash frequency and severity: evaluating the effectiveness of shoulder rumble strips on reducing fatal and major injury crashes.

PubMed

Wu, Kun-Feng; Donnell, Eric T; Aguero-Valverde, Jonathan

2014-06-01

To approach the goal of "Toward Zero Deaths," there is a need to develop an analysis paradigm to better understand the effects of a countermeasure on reducing the number of severe crashes. One of the goals in traffic safety research is to search for an effective treatment to reduce fatal and major injury crashes, referred to as severe crashes. To achieve this goal, the selection of promising countermeasures is of utmost importance, and relies on the effectiveness of candidate countermeasures in reducing severe crashes. Although it is important to precisely evaluate the effectiveness of candidate countermeasures in reducing the number of severe crashes at a site, the current state-of-the-practice often leads to biased estimates. While there have been a few advanced statistical models developed to mitigate the problem in practice, these models are computationally difficult to estimate because severe crashes are dispersed spatially and temporally, and cannot be integrated into the Highway Safety Manual framework, which develops a series of safety performance functions and crash modification factors to predict the number of crashes. Crash severity outcomes are generally integrated into the Highway Safety Manual using deterministic distributions rather than statistical models. Accounting for the variability in crash severity as a function geometric design, traffic flow, and other roadway and roadside features is afforded by estimating statistical models. Therefore, there is a need to develop a new analysis paradigm to resolve the limitations in the current Highway Safety Manual methods. We propose an approach which decomposes the severe crash frequency into a function of the change in the total number of crashes and the probability of a crash becoming a severe crash before and after a countermeasure is implemented. We tested this approach by evaluating the effectiveness of shoulder rumble strips on reducing the number of severe crashes. A total of 310 segments that have had shoulder rumble strips installed during 2002-2009 are included in the analysis. It was found that shoulder rumble strips reduce the total number of crashes, but have no statistically significant effect on reducing the probability of a severe crash outcome. Copyright © 2014 Elsevier Ltd. All rights reserved.

Generalized thick strip modelling for vortex-induced vibration of long flexible cylinders

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

Bao, Y., E-mail: ybao@sjtu.edu.cn; Department of Aeronautics, Imperial College London, South Kensington Campus, London; Palacios, R., E-mail: r.palacios@imperial.ac.uk

2016-09-15

We propose a generalized strip modelling method that is computationally efficient for the VIV prediction of long flexible cylinders in three-dimensional incompressible flow. In order to overcome the shortcomings of conventional strip-theory-based 2D models, the fluid domain is divided into “thick” strips, which are sufficiently thick to locally resolve the small scale turbulence effects and three dimensionality of the flow around the cylinder. An attractive feature of the model is that we independently construct a three-dimensional scale resolving model for individual strips, which have local spanwise scale along the cylinder's axial direction and are only coupled through the structural modelmore » of the cylinder. Therefore, this approach is able to cover the full spectrum for fully resolved 3D modelling to 2D strip theory. The connection between these strips is achieved through the calculation of a tensioned beam equation, which is used to represent the dynamics of the flexible body. In the limit, however, a single “thick” strip would fill the full 3D domain. A parallel Fourier spectral/hp element method is employed to solve the 3D flow dynamics in the strip-domain, and then the VIV response prediction is achieved through the strip–structure interactions. Numerical tests on both laminar and turbulent flows as well as the comparison against the fully resolved DNS are presented to demonstrate the applicability of this approach.« less

Constraints on the Evolution of the Galaxy Stellar Mass Function I: Role of Star Formation, Mergers, and Stellar Stripping

NASA Astrophysics Data System (ADS)

Contini, E.; Kang, Xi; Romeo, A. D.; Xia, Q.

2017-03-01

We study the connection between the observed star formation rate-stellar mass (SFR-M *) relation and the evolution of the stellar mass function (SMF) by means of a subhalo abundance matching technique coupled to merger trees extracted from an N-body simulation. Our approach, which considers both galaxy mergers and stellar stripping, is to force the model to match the observed SMF at redshift z> 2, and let it evolve down to the present time according to the observed SFR-M * relation. In this study, we use two different sets of SMFs and two SFR-M * relations: a simple power law and a relation with a mass-dependent slope. Our analysis shows that the evolution of the SMF is more consistent with an SFR-M * relation with a mass-dependent slope, in agreement with predictions from other models of galaxy evolution and recent observations. In order to fully and realistically describe the evolution of the SMF, both mergers and stellar stripping must be considered, and we find that both have almost equal effects on the evolution of SMF at the massive end. Taking into account the systematic uncertainties in the observed data, the high-mass end of the SMF obtained by considering stellar stripping results in good agreement with recent observational data from the Sloan Digital Sky Survey. At {log} {M}* < 11.2, our prediction at z = 0.1 is close to Li & White data, but the high-mass end ({log} {M}* > 11.2) is in better agreement with D’Souza et al. data which account for more massive galaxies.

Addressing the too big to fail problem with baryon physics and sterile neutrino dark matter

NASA Astrophysics Data System (ADS)

Lovell, Mark R.; Gonzalez-Perez, Violeta; Bose, Sownak; Boyarsky, Alexey; Cole, Shaun; Frenk, Carlos S.; Ruchayskiy, Oleg

2017-07-01

N-body dark matter simulations of structure formation in the Λ cold dark matter (ΛCDM) model predict a population of subhaloes within Galactic haloes that have higher central densities than inferred for the Milky Way satellites, a tension known as the 'too big to fail' problem. Proposed solutions include baryonic effects, a smaller mass for the Milky Way halo and warm dark matter (WDM). We test these possibilities using a semi-analytic model of galaxy formation to generate luminosity functions for Milky Way halo-analogue satellite populations, the results of which are then coupled to the Jiang & van den Bosch model of subhalo stripping to predict the subhalo Vmax functions for the 10 brightest satellites. We find that selecting the brightest satellites (as opposed to the most massive) and modelling the expulsion of gas by supernovae at early times increases the likelihood of generating the observed Milky Way satellite Vmax function. The preferred halo mass is 6 × 1011 M⊙, which has a 14 per cent probability to host a Vmax function like that of the Milky Way satellites. We conclude that the Milky Way satellite Vmax function is compatible with a CDM cosmology, as previously found by Sawala et al. using hydrodynamic simulations. Sterile neutrino-WDM models achieve a higher degree of agreement with the observations, with a maximum 50 per cent chance of generating the observed Milky Way satellite Vmax function. However, more work is required to check that the semi-analytic stripping model is calibrated correctly for each sterile neutrino cosmology.

Airfoil System for Cruising Flight

NASA Technical Reports Server (NTRS)

Shams, Qamar A. (Inventor); Liu, Tianshu (Inventor)

2014-01-01

An airfoil system includes an airfoil body and at least one flexible strip. The airfoil body has a top surface and a bottom surface, a chord length, a span, and a maximum thickness. Each flexible strip is attached along at least one edge thereof to either the top or bottom surface of the airfoil body. The flexible strip has a spanwise length that is a function of the airfoil body's span, a chordwise width that is a function of the airfoil body's chord length, and a thickness that is a function of the airfoil body's maximum thickness.

Austenite grain growth kinetics in Al-killed plain carbon steels

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

Militzer, M.; Giumelli, A.; Hawbolt, E.B.

1996-11-01

Austenite grain growth kinetics have been investigated in three Al-killed plain carbon steels. Experimental results have been validated using the statistical grain growth model by Abbruzzese and Luecke, which takes pinning by second-phase particles into account. It is shown that the pinning force is a function of the pre-heat-treatment schedule. Extrapolation to the conditions of a hot-strip mill indicates that grain growth occurs without pinning during conventional processing. Analytical relations are proposed to simulate austenite grain growth for Al-killed plain carbon steels for any thermal path in a hot-strip mill.

Quadratic forms involving Green's and Robin functions

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

Dubinin, Vladimir N

2009-10-31

General inequalities for quadratic forms with coefficients depending on the values of Green's and Robin functions are obtained. These inequalities cover also the reduced moduli of strips and half-strips. Some applications of the results obtained to extremal partitioning problems and related questions of geometric function theory are discussed. Bibliography: 29 titles.

A model for prediction of profile and flatness of hot and cold rolled flat products in four-high mills

NASA Astrophysics Data System (ADS)

Overhagen, Christian; Mauk, Paul Josef

2018-05-01

For flat rolled products, the thickness profile in the transversal direction is one of the most important product properties. For further processing, a defined crown of the product is necessary. In the rolling process, several mechanical and thermal influences interact with each other to form the strip shape at the roll gap exit. In the present analysis, a process model for rolling of strip and sheet is presented. The core feature of the process model is a two-dimensional stress distribution model based on von Karman's differential equation. Sub models for the mechanical influences of work roll flattening as well as work and backup roll deflection and the thermal influence of work roll expansion have been developed or extended. The two-dimensional stress distribution serves as an input parameter for the roll deformation models. For work roll flattening, a three-dimensional model based on the Boussinesq problem is adopted, while the work and backup roll deflection, including contact flattening is calculated by means of finite beam elements. The thermal work roll crown is calculated with help of an axisymmetric numerical solution of the heat equation for the work roll, considering azimuthal averaging for the boundary conditions at the work roll surface. Results are presented for hot rolling of a strip in a seven-stand finishing train of a hot strip mill, showing the calculated evolution of the strip profile. A variation of the strip profile from the first to the 20th rolled strip is shown. This variation is addressed to the progressive increase of work roll temperature during the first 20 strips. It is shown that a CVC® system can lead to improvements in strip profile and therefore flatness.

Getting More Power from Your Flowers: Multi-Functional Flower Strips Enhance Pollinators and Pest Control Agents in Apple Orchards.

PubMed

Campbell, Alistair John; Wilby, Andrew; Sutton, Peter; Wäckers, Felix

2017-09-20

Flower strips are commonly recommended to boost biodiversity and multiple ecosystem services (e.g., pollination and pest control) on farmland. However, significant knowledge gaps remain regards the extent to which they deliver on these aims. Here, we tested the efficacy of flower strips that targeted different subsets of beneficial arthropods (pollinators and natural enemies) and their ecosystem services in cider apple orchards. Treatments included mixes that specifically targeted: (1) pollinators ('concealed-nectar plants'); (2) natural enemies ('open-nectar plants'); or (3) both groups concurrently (i.e., 'multi-functional' mix). Flower strips were established in alleyways of four orchards and compared to control alleyways (no flowers). Pollinator (e.g., bees) and natural enemy (e.g., parasitoid wasps, predatory flies and beetles) visitation to flower strips, alongside measures of pest control (aphid colony densities, sentinel prey predation), and fruit production, were monitored in orchards over two consecutive growing seasons. Targeted flower strips attracted either pollinators or natural enemies, whereas mixed flower strips attracted both groups in similar abundance to targeted mixes. Natural enemy densities on apple trees were higher in plots containing open-nectar plants compared to other treatments, but effects were stronger for non-aphidophagous taxa. Predation of sentinel prey was enhanced in all flowering plots compared to controls but pest aphid densities and fruit yield were unaffected by flower strips. We conclude that 'multi-functional' flower strips that contain flowering plant species with opposing floral traits can provide nectar and pollen for both pollinators and natural enemies, but further work is required to understand their potential for improving pest control services and yield in cider apple orchards.

Vehicle influence on permeation through intact and compromised skin.

PubMed

Gujjar, Meera; Banga, Ajay K

2014-09-10

The purpose of this study was to compare the transdermal permeation of a model compound, diclofenac diethylamine, from a hydrophilic and lipophilic vehicle across in vitro models simulating compromised skin. Mineral oil served as a lipophilic vehicle while 10mM phosphate buffered saline served as a hydrophilic vehicle. Compromised skin was simulated by tape stripping, delipidization, or microneedle application and compared with intact skin as a control. Transepidermal water loss was measured to assess barrier function. Skin compromised with tape stripping and delipidization significantly (p<0.05) increased permeation of diclofenac diethylamine compared to intact and microneedle treated skin with phosphate buffered saline vehicle. A similar trend in permeation was observed with mineral oil as the vehicle. For both vehicles, permeation across skin increased in the same order and correlated with degree of barrier impairment as indicated by transepidermal water loss values: intact

Daikenchuto ameliorates muscle hypercontractility in a murine T-cell-mediated persistent gut motor dysfunction model.

PubMed

Akiho, Hirotada; Nakamura, Kazuhiko

2011-01-01

Low-grade inflammation and immunological alterations are evident in functional gastrointestinal disorders such as irritable bowel syndrome (IBS). We evaluated the effects of daikenchuto (DKT), a pharmaceutical grade Japanese herbal medicine, on the hypercontractility of intestinal smooth muscle persisting after acute inflammation induced by a T-cell-activating anti-CD3 antibody (αCD3). BALB/c mice were injected with αCD3 (12.5 μg, i.p.), and DKT (2.7 g/kg) was administered orally once daily for 1 week. The contraction of isolated small intestinal muscle strips and muscle cells was examined on day 7 after αCD3 injection. The gene and protein expressions in the small intestines were evaluated by real-time PCR and multiplex immunoassays, respectively, on days 1, 3 and 7 after αCD3 injection. αCD3 injection resulted in significant increases in carbachol-evoked contractility in the muscle strips and isolated smooth muscle cells on day 7. DKT ameliorated the αCD3-induced muscle hypercontractility on day 7 in both the muscle strips and smooth muscle cells. αCD3 injection rapidly up- and downregulated the mRNA and protein expressions of pro- and anti-inflammatory cytokines, respectively. Although the influence of DKT on the mRNA expressions was moderate, the protein expressions of IL-13 and IL-17 were significantly decreased. We observed changes in the intestinal muscle contractility in muscle strips and muscle cells following resolution of inflammation in a T-cell-mediated model of enteropathy. The observed modulation of cytokine expression and function by DKT may lead to the development of new pharmacotherapeutic strategies aimed at a wide variety of gut motor dysfunction disorders. Copyright © 2011 S. Karger AG, Basel.

Approximate strip exchanging.

PubMed

Roy, Swapnoneel; Thakur, Ashok Kumar

2008-01-01

Genome rearrangements have been modelled by a variety of primitives such as reversals, transpositions, block moves and block interchanges. We consider such a genome rearrangement primitive Strip Exchanges. Given a permutation, the challenge is to sort it by using minimum number of strip exchanges. A strip exchanging move interchanges the positions of two chosen strips so that they merge with other strips. The strip exchange problem is to sort a permutation using minimum number of strip exchanges. We present here the first non-trivial 2-approximation algorithm to this problem. We also observe that sorting by strip-exchanges is fixed-parameter-tractable. Lastly we discuss the application of strip exchanges in a different area Optical Character Recognition (OCR) with an example.

Equivalent-circuit models for electret-based vibration energy harvesters

NASA Astrophysics Data System (ADS)

Phu Le, Cuong; Halvorsen, Einar

2017-08-01

This paper presents a complete analysis to build a tool for modelling electret-based vibration energy harvesters. The calculational approach includes all possible effects of fringing fields that may have significant impact on output power. The transducer configuration consists of two sets of metal strip electrodes on a top substrate that faces electret strips deposited on a bottom movable substrate functioning as a proof mass. Charge distribution on each metal strip is expressed by series expansion using Chebyshev polynomials multiplied by a reciprocal square-root form. The Galerkin method is then applied to extract all charge induction coefficients. The approach is validated by finite element calculations. From the analytic tool, a variety of connection schemes for power extraction in slot-effect and cross-wafer configurations can be lumped to a standard equivalent circuit with inclusion of parasitic capacitance. Fast calculation of the coefficients is also obtained by a proposed closed-form solution based on leading terms of the series expansions. The achieved analytical result is an important step for further optimisation of the transducer geometry and maximising harvester performance.

[Comparative experiments of stripping sheep maxillary sinus mucosal with new-type stripper and umbrella detacher].

PubMed

Jiadong, Fan; Yanfeng, Li; Le, Liu; Yishi, Han; Pin, Hu; Yue, Zhang; Wenya, Bao

2016-10-01

To compare the stripping length obtained through the model of 0.012 and 0.014 of the nickel-titanium dual-stage maxillary sinus mucosa stripper, and the umbrella detacher. Twenty-four goats (1.5-2 years old) were chosen, randomly divided into A, B, C groups, each group of eight. Group A was 0.012 model group, group B was 0.014 model group, group C was umbrella detacher group. Animal model was established, and maxillary sinus mucosa was stripped to the left and right sides of the bottom of the sinus in three groups. The data was measured when stripping to the limit or being perforated. The average length of group A was 12.41 mm±4.35 mm, two cases perforated. The average length of group B was 23.38 mm±4.84 mm, one case perforated. The average length of group C was 2.61 mm±0.30 mm. The population mean of stripping length in three groups was not all the same calculated by analysis of variance (P<0.01). There were significant differences in the stripping length of the three groups by the SNK test (P<0.05). The nickel-titanium dual-stage maxillary sinus mucosa stripper can achieve a larger mucosal stripping range. The stripper with a model of 0.014 has a moderate flexibility and safety, and it can strip a large area of sinus mucosa.
.

Study of electrode pattern design for a CZT-based PET detector.

PubMed

Gu, Y; Levin, C S

2014-06-07

We are developing a 1 mm resolution small animal positron emission tomography (PET) system using 3D positioning cadmium zinc telluride photon detectors comprising 40 mm × 40 mm × 5 mm crystals metalized with a cross-strip electrode pattern with a 1 mm anode strip pitch. We optimized the electrode pattern design for intrinsic sensitivity and spatial, energy and time resolution performance using a test detector comprising cathode and steering electrode strips of varying dimensions. The study found 3 and 5 mm width cathode strips locate charge-shared photon interactions near cathode strip boundaries with equal precision. 3 mm width cathode strips exhibited large time resolution variability as a function of photon interaction location between the anode and cathode planes (~26 to ~127.5 ns full width at half maximum (FWHM) for 0.5 mm and 4.2 mm depths, respectively). 5 mm width cathode strips by contrast exhibited more stable time resolution for the same interaction locations (~34 to ~83 ns FWHM), provided more linear spatial positioning in the direction orthogonal to the electrode planes, and as much as 68.4% improvement in photon sensitivity over the 3 mm wide cathode strips. The results were understood by analyzing the cathode strips' weighting functions, which indicated a stronger 'small pixel' effect in the 3 mm wide cathode strips. Photon sensitivity and anode energy resolution were seen to improve with decreasing steering electrode bias from 0 to -80 V w.r.t. the anode potential. A slight improvement in energy resolution was seen for wider steering electrode strips (400 versus 100 µm) for charge-shared photon interactions. Although this study successfully focused on electrode pattern features for PET performance, the results are generally applicable to semiconductor photon detectors employing cross-trip electrode patterns.

Fracture analysis of a transversely isotropic high temperature superconductor strip based on real fundamental solutions

NASA Astrophysics Data System (ADS)

Gao, Zhiwen; Zhou, Youhe

2015-04-01

Real fundamental solution for fracture problem of transversely isotropic high temperature superconductor (HTS) strip is obtained. The superconductor E-J constitutive law is characterized by the Bean model where the critical current density is independent of the flux density. Fracture analysis is performed by the methods of singular integral equations which are solved numerically by Gauss-Lobatto-Chybeshev (GSL) collocation method. To guarantee a satisfactory accuracy, the convergence behavior of the kernel function is investigated. Numerical results of fracture parameters are obtained and the effects of the geometric characteristics, applied magnetic field and critical current density on the stress intensity factors (SIF) are discussed.

Erosion rills offset the efficacy of vegetated buffer strips to mitigate pesticide exposure in surface waters.

PubMed

Stehle, Sebastian; Dabrowski, James Michael; Bangert, Uli; Schulz, Ralf

2016-03-01

Regulatory risk assessment considers vegetated buffer strips as effective risk mitigation measures for the reduction of runoff-related pesticide exposure of surface waters. However, apart from buffer strip widths, further characteristics such as vegetation density or the presence of erosion rills are generally neglected in the determination of buffer strip mitigation efficacies. This study conducted a field survey of fruit orchards (average slope 3.1-12.2%) of the Lourens River catchment, South Africa, which specifically focused on the characteristics and attributes of buffer strips separating orchard areas from tributary streams. In addition, in-stream and erosion rill water samples were collected during three runoff events and GIS-based modeling was employed to predict losses of pesticides associated with runoff. The results show that erosion rills are common in buffer strips (on average 13 to 24 m wide) of the tributaries (up to 6.5 erosion rills per km flow length) and that erosion rills represent concentrated entry pathways of pesticide runoff into the tributaries during rainfall events. Exposure modeling shows that measured pesticide surface water concentrations correlated significantly (R(2)=0.626; p<0.001) with runoff losses predicted by the modeling approach in which buffer strip width was set to zero at sites with erosion rills; in contrast, no relationship between predicted runoff losses and in-stream pesticide concentrations were detected in the modeling approach that neglected erosion rills and thus assumed efficient buffer strips. Overall, the results of our study show that erosion rills may substantially reduce buffer strip pesticide retention efficacies during runoff events and suggest that the capability of buffer strips as a risk mitigation tool for runoff is largely overestimated in current regulatory risk assessment procedures conducted for pesticide authorization. Copyright © 2015 Elsevier B.V. All rights reserved.

Rematching AGS Booster synchrotron injection lattice for smaller transverse beam emittances

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

Liu, C.; Beebe-Wang, J.; Brown, K.

2017-01-25

The polarized proton beam is injected into the booster via the charge-exchange (H- to H+) scheme. The emittance growth due to scattering at the stripping foil is proportional to the beta functions at the foil. It was demonstrated that the current scheme of reducing the beta functions at the stripping foil preserves the emittance better; however the betatron tunes are above but very close to half integer. Due to concern of space charge and half integer in general, options of lattice designs aimed towards reducing the beta functions at the stripping foil with tunes at more favorable places are explored.

Evaluation of the relative roles of a vegetative filter strip and a biofiltration swale in a treatment train for road runoff.

PubMed

Flanagan, Kelsey; Branchu, Philippe; Ramier, David; Gromaire, Marie-Christine

2017-02-01

In order to determine the relative importance of a vegetative filter strip and a biofiltration swale in a treatment train for road runoff, US EPA Storm Water Management Model was used to model infiltration and runoff from the filter strip. The model consisted of a series of subcatchments representing the road, the filter strip and the side-slopes of the swale. Simulations were carried out for different rain scenarios representing a variety of climatic conditions. In addition, a sensitivity analysis was conducted for the model's different parameters (soil characteristics and initial humidity, roughness, geometry, etc.). This exercise showed that for the system studied, the majority of road runoff is treated by the filter strip rather than the biofiltration swale, an effect observed especially during periods of low-intensity rainfall. Additionally, it was observed that the combination of infiltration of road runoff in the filter strip and direct rainfall on the system leads to a significant and variable dilution of the runoff reaching the swale. This result has important implications for evaluating the treatment efficiency of the system.

Multidimensional Models of Type Ia Supernova Nebular Spectra: Strong Emission Lines from Stripped Companion Gas Rule Out Classic Single-degenerate Systems

NASA Astrophysics Data System (ADS)

Botyánszki, János; Kasen, Daniel; Plewa, Tomasz

2018-01-01

The classic single-degenerate model for the progenitors of Type Ia supernova (SN Ia) predicts that the supernova ejecta should be enriched with solar-like abundance material stripped from the companion star. Spectroscopic observations of normal SNe Ia at late times, however, have not resulted in definite detection of hydrogen. In this Letter, we study line formation in SNe Ia at nebular times using non-LTE spectral modeling. We present, for the first time, multidimensional radiative transfer calculations of SNe Ia with stripped material mixed in the ejecta core, based on hydrodynamical simulations of ejecta–companion interaction. We find that interaction models with main-sequence companions produce significant Hα emission at late times, ruling out these types of binaries being viable progenitors of SNe Ia. We also predict significant He I line emission at optical and near-infrared wavelengths for both hydrogen-rich or helium-rich material, providing an additional observational probe of stripped ejecta. We produce models with reduced stripped masses and find a more stringent mass limit of M st ≲ 1 × 10‑4 M ⊙ of stripped companion material for SN 2011fe.

Optimal Cluster Mill Pass Scheduling With an Accurate and Rapid New Strip Crown Model

NASA Astrophysics Data System (ADS)

Malik, Arif S.; Grandhi, Ramana V.; Zipf, Mark E.

2007-05-01

Besides the requirement to roll coiled sheet at high levels of productivity, the optimal pass scheduling of cluster-type reversing cold mills presents the added challenge of assigning mill parameters that facilitate the best possible strip flatness. The pressures of intense global competition, and the requirements for increasingly thinner, higher quality specialty sheet products that are more difficult to roll, continue to force metal producers to commission innovative flatness-control technologies. This means that during the on-line computerized set-up of rolling mills, the mathematical model should not only determine the minimum total number of passes and maximum rolling speed, it should simultaneously optimize the pass-schedule so that desired flatness is assured, either by manual or automated means. In many cases today, however, on-line prediction of strip crown and corresponding flatness for the complex cluster-type rolling mills is typically addressed either by trial and error, by approximate deflection models for equivalent vertical roll-stacks, or by non-physical pattern recognition style models. The abundance of the aforementioned methods is largely due to the complexity of cluster-type mill configurations and the lack of deflection models with sufficient accuracy and speed for on-line use. Without adequate assignment of the pass-schedule set-up parameters, it may be difficult or impossible to achieve the required strip flatness. In this paper, we demonstrate optimization of cluster mill pass-schedules using a new accurate and rapid strip crown model. This pass-schedule optimization includes computations of the predicted strip thickness profile to validate mathematical constraints. In contrast to many of the existing methods for on-line prediction of strip crown and flatness on cluster mills, the demonstrated method requires minimal prior tuning and no extensive training with collected mill data. To rapidly and accurately solve the multi-contact problem and predict the strip crown, a new customized semi-analytical modeling technique that couples the Finite Element Method (FEM) with classical solid mechanics was developed to model the deflection of the rolls and strip while under load. The technique employed offers several important advantages over traditional methods to calculate strip crown, including continuity of elastic foundations, non-iterative solution when using predetermined foundation moduli, continuous third-order displacement fields, simple stress-field determination, and a comparatively faster solution time.

Study of electrode pattern design for a CZT-based PET detector

PubMed Central

Gu, Y; Levin, C S

2014-01-01

We are developing a 1 mm resolution small animal positron emission tomography (PET) system using 3-D positioning Cadmium Zinc Telluride (CZT) photon detectors comprising 40 mm × 40 mm × 5 mm crystals metalized with a cross-strip electrode pattern with a 1 mm anode strip pitch. We optimized the electrode pattern design for intrinsic sensitivity and spatial, energy and time resolution performance using a test detector comprising cathode and steering electrode strips of varying dimensions. The study found 3 mm and 5 mm width cathode strips locate charge-shared photon interactions near cathode strip boundaries with equal precision. 3 mm width cathode strips exhibited large time resolution variability as a function of photon interaction location between the anode and cathode planes (~26 ns to ~127.5 ns FWHM for 0.5 mm and 4.2 mm depths, respectively). 5 mm width cathode strips by contrast exhibited more stable time resolution for the same interaction locations (~34 ns to ~83 ns FWHM), provided more linear spatial positioning in the direction orthogonal to the electrode planes, and as much as 68.4% improvement in photon sensitivity over the 3 mm wide cathode strips. The results were understood by analyzing the cathode strips’ weighting functions, which indicated a stronger “small pixel” effect in the 3 mm wide cathode strips. Photon sensitivity and anode energy resolution were seen to improve with decreasing steering electrode bias from 0 V to −80 V w.r.t the anode potential. A slight improvement in energy resolution was seen for wider steering electrode strips (400 μm vs. 100 μm) for charge-shared photon interactions. Although this study successfully focused on electrode pattern features for PET performance, the results are generally applicable to semiconductor photon detectors employing cross-trip electrode patterns. PMID:24786208

Extensions in Pen Ink Dosimetry: Ultraviolet Calibration Applications for Primary and Secondary Schools

ERIC Educational Resources Information Center

Downs, Nathan; Parisi, Alfio; Powell, Samantha; Turner, Joanna; Brennan, Chris

2010-01-01

A technique has previously been described for secondary school-aged children to make ultraviolet (UV) dosimeters from highlighter pen ink drawn onto strips of paper. This technique required digital comparison of exposed ink paper strips with unexposed ink paper strips to determine a simple calibration function relating the degree of ink fading to…

Design, Fabrication, and Implementation of a Wireless, Passive Implantable Pressure Sensor Based on Magnetic Higher-Order Harmonic Fields

PubMed Central

Tan, Ee Lim; DeRouin, Andrew J.; Pereles, Brandon D.; Ong, Keat Ghee

2011-01-01

A passive and wireless sensor was developed for monitoring pressure in vivo. Structurally, the pressure sensor, referred to as the magneto-harmonic pressure sensor, is an airtight chamber sealed with an elastic pressure membrane. A strip of magnetically-soft material is attached to the bottom of the chamber and a permanent magnet strip is embedded inside the membrane. Under the excitation of an externally applied AC magnetic field, the magnetically-soft strip produces a higher-order magnetic signature that can be remotely detected with an external receiving coil. As ambient pressure varies, the pressure membrane deflects, altering the separation distance between the magnetically-soft strip and the permanent magnet. This shifts the higher-order harmonic signal, allowing for detection of pressure change as a function of harmonic shifting. The wireless, passive nature of this sensor technology allows for continuous long-term pressure monitoring, particularly useful for biomedical applications such as monitoring pressure in aneurysm sac and sphincter of Oddi. In addition to demonstrating its pressure sensing capability, an animal model was used to investigate the efficacy and feasibility of the pressure sensor in a biological environment. PMID:25585564

Avoiding social traps in the ecosystem stewardship: The Italian Fontanile lowland spring.

PubMed

Balderacchi, Matteo; Perego, Alessia; Lazzari, Giovanni; Muñoz-Carpena, Rafael; Acutis, Marco; Laini, Alex; Giussani, Andrea; Sanna, Mattia; Kane, David; Trevisan, Marco

2016-01-01

Fontanile is a Po Valley (Italy) quasi-natural lowland spring built in the middle age. This paper identifies options for the conservation of the Fontanile water dependent ecosystem, using scenarios and simulations, and exploring different policy options. Three modeling analysis have been performed: the first was carried out for estimating groundwater contamination and recharge from above, the second for evaluating the function of vegetative filter strip on the surface water quality and the last one for testing pesticide drift reduction due to the vegetative filter strip. Uncertainty characterization included climate change projections. Despite the nitrate concentration in water could favorite the eutrophication phenomena, this not occurs because of the low phosphate concentration in water and of the presence of arboreal shade. Therefore, the protection strategies must focus on sustaining desirable water quantity conditions. Water saving and conservation technologies that improve the agricultural productivity but reduce the Fontanile water flow and large buffer strips that have a limited efficacy due to the Fontanile hydrological settings can be judged as ecological traps. Inefficient irrigation systems, good agricultural practices, integrated pest management and arboreal filter strip can preserve the quality of those ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Model modifications for simulation of flow through stratified rocks in eastern Ohio

USGS Publications Warehouse

Helgesen, J.O.; Razem, A.C.; Larson, S.P.

1982-01-01

A quasi three-dimensional groundwater flow model is being used as part of a study to determine impacts of coal-strip mining on local hydrologic systems. Modifications to the model were necessary to simulate local hydrologic conditions properly. Perched water tables required that the method of calculating vertical flow rate be changed. A head-dependent spring-discharge function and a head-dependent stream aquifer-interchange function were added to the program. Modifications were also made to allow recharge from precipitation to any layer. The modified program, data deck instructions, and sample input and output are presented. (USGS)

Integrated Joule switches for the control of current dynamics in parallel superconducting strips

NASA Astrophysics Data System (ADS)

Casaburi, A.; Heath, R. M.; Cristiano, R.; Ejrnaes, M.; Zen, N.; Ohkubo, M.; Hadfield, R. H.

2018-06-01

Understanding and harnessing the physics of the dynamic current distribution in parallel superconducting strips holds the key to creating next generation sensors for single molecule and single photon detection. Non-uniformity in the current distribution in parallel superconducting strips leads to low detection efficiency and unstable operation, preventing the scale up to large area sensors. Recent studies indicate that non-uniform current distributions occurring in parallel strips can be understood and modeled in the framework of the generalized London model. Here we build on this important physical insight, investigating an innovative design with integrated superconducting-to-resistive Joule switches to break the superconducting loops between the strips and thus control the current dynamics. Employing precision low temperature nano-optical techniques, we map the uniformity of the current distribution before- and after the resistive strip switching event, confirming the effectiveness of our design. These results provide important insights for the development of next generation large area superconducting strip-based sensors.

Experiments on the Motion of Drops on a Horizontal Solid Surface due to a Wettability Gradient

NASA Technical Reports Server (NTRS)

Moumen, Nadjoua; Subramanian, R, Shankar; MLaughlin, john B.

2006-01-01

Results from experiments performed on the motion of drops of tetraethylene glycol in a wettability gradient present on a silicon surface are reported and compared with predictions from a recently developed theoretical model. The gradient in wettability was formed by exposing strips cut from a silicon wafer to decyltrichlorosiland vapors. Video images of the drops captured during the experiments were subsequently analyzed for drop size and velocity as functions of position along the gradient. In separate experiments on the same strips, the static contact angle formed by small drops was measured and used to obtain the local wettability gradient to which a drop is subjected. The velocity of the drops was found to be a strong function of position along the gradient. A quasi-steady theoretical model that balances the local hydrodynamic resistance with the local driving force generally describes the observations; possible reasons for the remaining discrepancies are discussed. It is shown that a model in which the driving force is reduced to accomodate the hysteresis effect inferred from the data is able to remove most of the discrepancy between the observed and predicted velocities.

Analysis of a Generally Oriented Crack in a Functionally Graded Strip Sandwiched Between Two Homogeneous Half Planes

NASA Technical Reports Server (NTRS)

Shbeeb, N.; Binienda, W. K.; Kreider, K.

1999-01-01

The driving forces for a generally oriented crack embedded in a Functionally Graded strip sandwiched between two half planes are analyzed using singular integral equations with Cauchy kernels, and integrated using Lobatto-Chebyshev collocation. Mixed-mode Stress Intensity Factors (SIF) and Strain Energy Release Rates (SERR) are calculated. The Stress Intensity Factors are compared for accuracy with previously published results. Parametric studies are conducted for various nonhomogeneity ratios, crack lengths. crack orientation and thickness of the strip. It is shown that the SERR is more complete and should be used for crack propagation analysis.

Evaluation of radio-tracking and strip transect methods for determining foraging ranges of Black-Legged Kittiwakes

USGS Publications Warehouse

Ostrand, William D.; Drew, G.S.; Suryan, R.M.; McDonald, L.L.

1998-01-01

We compared strip transect and radio-tracking methods of determining foraging range of Black-legged Kittiwakes (Rissa tridactyla). The mean distance birds were observed from their colony determined by radio-tracking was significantly greater than the mean value calculated from strip transects. We determined that this difference was due to two sources of bias: (1) as distance from the colony increased, the area of available habitat also increased resulting in decreasing bird densities (bird spreading). Consequently, the probability of detecting birds during transect surveys also would decrease as distance from the colony increased, and (2) the maximum distance birds were observed from the colony during radio-tracking exceeded the extent of the strip transect survey. We compared the observed number of birds seen on the strip transect survey to the predictions of a model of the decreasing probability of detection due to bird spreading. Strip transect data were significantly different from modeled data; however, the field data were consistently equal to or below the model predictions, indicating a general conformity to the concept of declining detection at increasing distance. We conclude that radio-tracking data gave a more representative indication of foraging distances than did strip transect sampling. Previous studies of seabirds that have used strip transect sampling without accounting for bird spreading or the effects of study-area limitations probably underestimated foraging range.

A design aid for determining width of filter strips

Treesearch

M.G. Dosskey; M.J. Helmers; D.E. Eisenhauer

2008-01-01

watershed planners need a tool for determining width of filter strips that is accurate enough for developing cost-effective site designs and easy enough to use for making quick determinations on a large number and variety of sites.This study employed the process-based Vegetative Filter Strip Model to evaluate the relationship between filter strip width and trapping...

Stability of barotropic vortex strip on a rotating sphere

PubMed Central

Sohn, Sung-Ik; Kim, Sun-Chul

2018-01-01

We study the stability of a barotropic vortex strip on a rotating sphere, as a simple model of jet streams. The flow is approximated by a piecewise-continuous vorticity distribution by zonal bands of uniform vorticity. The linear stability analysis shows that the vortex strip becomes stable as the strip widens or the rotation speed increases. When the vorticity constants in the upper and the lower regions of the vortex strip have the same positive value, the inner flow region of the vortex strip becomes the most unstable. However, when the upper and the lower vorticity constants in the polar regions have different signs, a complex pattern of instability is found, depending on the wavenumber of perturbations, and interestingly, a boundary far away from the vortex strip can be unstable. We also compute the nonlinear evolution of the vortex strip on the rotating sphere and compare with the linear stability analysis. When the width of the vortex strip is small, we observe a good agreement in the growth rate of perturbation at an early time, and the eigenvector corresponding to the unstable eigenvalue coincides with the most unstable part of the flow. We demonstrate that a large structure of rolling-up vortex cores appears in the vortex strip after a long-time evolution. Furthermore, the geophysical relevance of the model to jet streams of Jupiter, Saturn and Earth is examined. PMID:29507524

Stability of barotropic vortex strip on a rotating sphere.

PubMed

Sohn, Sung-Ik; Sakajo, Takashi; Kim, Sun-Chul

2018-02-01

We study the stability of a barotropic vortex strip on a rotating sphere, as a simple model of jet streams. The flow is approximated by a piecewise-continuous vorticity distribution by zonal bands of uniform vorticity. The linear stability analysis shows that the vortex strip becomes stable as the strip widens or the rotation speed increases. When the vorticity constants in the upper and the lower regions of the vortex strip have the same positive value, the inner flow region of the vortex strip becomes the most unstable. However, when the upper and the lower vorticity constants in the polar regions have different signs, a complex pattern of instability is found, depending on the wavenumber of perturbations, and interestingly, a boundary far away from the vortex strip can be unstable. We also compute the nonlinear evolution of the vortex strip on the rotating sphere and compare with the linear stability analysis. When the width of the vortex strip is small, we observe a good agreement in the growth rate of perturbation at an early time, and the eigenvector corresponding to the unstable eigenvalue coincides with the most unstable part of the flow. We demonstrate that a large structure of rolling-up vortex cores appears in the vortex strip after a long-time evolution. Furthermore, the geophysical relevance of the model to jet streams of Jupiter, Saturn and Earth is examined.

Prototyping of Silicon Strip Detectors for the Inner Tracker of the ALICE Experiment

NASA Astrophysics Data System (ADS)

Sokolov, Oleksiy

2006-04-01

The ALICE experiment at CERN will study heavy ion collisions at a center-of-mass energy 5.5˜TeV per nucleon. Particle tracking around the interaction region at radii r<45 cm is done by the Inner Tracking System (ITS), consisting of six cylindrical layers of silicon detectors. The outer two layers of the ITS use double-sided silicon strip detectors. This thesis focuses on testing of these detectors and performance studies of the detector module prototypes at the beam test. Silicon strip detector layers will require about 20 thousand HAL25 front-end readout chips and about 3.5 thousand hybrids each containing 6 HAL25 chips. During the assembly procedure, chips are bonded on a patterned TAB aluminium microcables which connect to all the chip input and output pads, and then the chips are assembled on the hybrids. Bonding failures at the chip or hybrid level may either render the component non-functional or deteriorate its the performance such that it can not be used for the module production. After each bonding operation, the component testing is done to reject the non-functional or poorly performing chips and hybrids. The LabView-controlled test station for this operation has been built at Utrecht University and was successfully used for mass production acceptance tests of chips and hybrids at three production labs. The functionality of the chip registers, bonding quality and analogue functionality of the chips and hybrids are addressed in the test. The test routines were optimized to minimize the testing time to make sure that testing is not a bottleneck of the mass production. For testing of complete modules the laser scanning station with 1060 nm diode laser has been assembled at Utrecht University. The testing method relies of the fact that a response of the detector module to a short collimated laser beam pulse resembles a response to a minimum ionizing particle. A small beam spot size (˜7 μm ) allows to deposit the charge in a narrow region and measure the response of individual detector channels. First several module prototypes have been studied with this setup, the strip gain and charge sharing function have been measured, the later is compared with the model predictions. It was also shown that for a laser beam of a high monochromaticity, interference in the sensor bulk significantly modulates the deposited charge and introduces a systematic error of the gain measurement. Signatures of disconnected strips and pinholes defects have been observed, the response of the disconnected strips to the laser beam has been correlated with the noise measurements. Beam test of four prototype modules have been carried out at PS accelerator at CERN using 7 GeV/c pions. It was demonstrated that the modules provide an excellent signal-to-noise ratio in the range 40-75. The estimated spatial resolution for the normally incident tracks is about 18 μm using the center-of-gravity cluster reconstruction method. A non-iterative method for spatial resolution determination was developed, it was shown that in order to determine the resolution of each individual detector in the telescope, the telescope should consist of at least 5 detectors. The detectors showed high detection efficiency, in the order 99%. It was shown that the particle loss occurs mostly in the defected regions near the noisy strips or strips with a very low gain. The efficiency of the sensor area with nominal characteristics is consistent with 100%.

Ourchestra.

ERIC Educational Resources Information Center

Sherman, Ross; Wright, Gary

1996-01-01

Provides a teaching strategy that uses Bloom's taxonomy and newspaper comic strips to promote higher-level thinking in elementary and secondary classrooms. Explains and demonstrates two functions of questioning (centering and expansion) using a Peanuts comic strip. (RS)

A design aid for sizing filter strips using buffer area ratio

Treesearch

M.G. Dosskey; M.J. Helmers; D.E. Eisenhauer

2011-01-01

Nonuniform field runoff can reduce the effectiveness of filter strips that are a uniform size along a field margin. Effectiveness can be improved by placing more filter strip where the runoff load is greater and less where the load is smaller. A modeling analysis was conducted of the relationship between pollutant trapping efficiency and the ratio of filter strip area...

Characterization of near-stoichiometric Ti:LiNbO(3) strip waveguides with varied substrate refractive index in the guiding layer.

PubMed

Zhang, De-Long; Zhang, Pei; Zhou, Hao-Jiang; Pun, Edwin Yue-Bun

2008-10-01

We have demonstrated the possibility that near-stoichiometric Ti:LiNbO(3) strip waveguides are fabricated by carrying out vapor transport equilibration at 1060 degrees C for 12 h on a congruent LiNbO(3) substrate with photolithographically patterned 4-8 microm wide, 115 nm thick Ti strips. Optical characterizations show that these waveguides are single mode at 1.5 microm and show a waveguide loss of 1.3 dB/cm for TM mode and 1.1 dB/cm for TE mode. In the width/depth direction of the waveguide, the mode field follows the Gauss/Hermite-Gauss function. Secondary-ion-mass spectrometry (SIMS) was used to study Ti-concentration profiles in the depth direction and on the surface of the 6 microm wide waveguide. The result shows that the Ti profile follows a sum of two error functions along the width direction and a complementary error function in the depth direction. The surface Ti concentration, 1/e width and depth, and mean diffusivities along the width and depth directions of the guide are similar to 3.0 x 10(21) cm(-3), 3.8 microm, 2.6 microm, 0.30 and 0.14 microm(2)/h, respectively. Micro-Raman analysis was carried out on the waveguide endface to characterize the depth profile of Li composition in the guiding layer. The results show that the depth profile of Li composition also follows a complementary error function with a 1/e depth of 3.64 microm. The mean ([Li(Li)]+[Ti(Li)])/([Nb(Nb)]+[Ti(Nb)]) ratio in the waveguide layer is about 0.98. The inhomogeneous Li-composition profile results in a varied substrate index in the guiding layer. A two-dimensional refractive index profile model in the waveguide is proposed by taking into consideration the varied substrate index and assuming linearity between Ti-induced index change and Ti concentration. The net waveguide surface index increments at 1545 nm are 0.0114 and 0.0212 for ordinary and extraordinary rays, respectively. Based upon the constructed index model, the fundamental mode field profile was calculated using the beam propagation method, and the mode sizes and effective index versus the Ti-strip width were calculated for three lower TM and TE modes using the variational method. An agreement between theory and experiment is obtained.

Study of surface properties of ATLAS12 strip sensors and their radiation resistance

NASA Astrophysics Data System (ADS)

Mikestikova, M.; Allport, P. P.; Baca, M.; Broughton, J.; Chisholm, A.; Nikolopoulos, K.; Pyatt, S.; Thomas, J. P.; Wilson, J. A.; Kierstead, J.; Kuczewski, P.; Lynn, D.; Hommels, L. B. A.; Ullan, M.; Bloch, I.; Gregor, I. M.; Tackmann, K.; Hauser, M.; Jakobs, K.; Kuehn, S.; Mahboubi, K.; Mori, R.; Parzefall, U.; Clark, A.; Ferrere, D.; Sevilla, S. Gonzalez; Ashby, J.; Blue, A.; Bates, R.; Buttar, C.; Doherty, F.; McMullen, T.; McEwan, F.; O'Shea, V.; Kamada, S.; Yamamura, K.; Ikegami, Y.; Nakamura, K.; Takubo, Y.; Unno, Y.; Takashima, R.; Chilingarov, A.; Fox, H.; Affolder, A. A.; Casse, G.; Dervan, P.; Forshaw, D.; Greenall, A.; Wonsak, S.; Wormald, M.; Cindro, V.; Kramberger, G.; Mandić, I.; Mikuž, M.; Gorelov, I.; Hoeferkamp, M.; Palni, P.; Seidel, S.; Taylor, A.; Toms, K.; Wang, R.; Hessey, N. P.; Valencic, N.; Hanagaki, K.; Dolezal, Z.; Kodys, P.; Bohm, J.; Stastny, J.; Bevan, A.; Beck, G.; Milke, C.; Domingo, M.; Fadeyev, V.; Galloway, Z.; Hibbard-Lubow, D.; Liang, Z.; Sadrozinski, H. F.-W.; Seiden, A.; To, K.; French, R.; Hodgson, P.; Marin-Reyes, H.; Parker, K.; Jinnouchi, O.; Hara, K.; Sato, K.; Hagihara, M.; Iwabuchi, S.; Bernabeu, J.; Civera, J. V.; Garcia, C.; Lacasta, C.; Marti i Garcia, S.; Rodriguez, D.; Santoyo, D.; Solaz, C.; Soldevila, U.

2016-09-01

A radiation hard n+-in-p micro-strip sensor for the use in the Upgrade of the strip tracker of the ATLAS experiment at the High Luminosity Large Hadron Collider (HL-LHC) has been developed by the "ATLAS ITk Strip Sensor collaboration" and produced by Hamamatsu Photonics. Surface properties of different types of end-cap and barrel miniature sensors of the latest sensor design ATLAS12 have been studied before and after irradiation. The tested barrel sensors vary in "punch-through protection" (PTP) structure, and the end-cap sensors, whose stereo-strips differ in fan geometry, in strip pitch and in edge strip ganging options. Sensors have been irradiated with proton fluences of up to 1×1016 neq/cm2, by reactor neutron fluence of 1×1015 neq/cm2 and by gamma rays from 60Co up to dose of 1 MGy. The main goal of the present study is to characterize the leakage current for micro-discharge breakdown voltage estimation, the inter-strip resistance and capacitance, the bias resistance and the effectiveness of PTP structures as a function of bias voltage and fluence. It has been verified that the ATLAS12 sensors have high breakdown voltage well above the operational voltage which implies that different geometries of sensors do not influence their stability. The inter-strip isolation is a strong function of irradiation fluence, however the sensor performance is acceptable in the expected range for HL-LHC. New gated PTP structure exhibits low PTP onset voltage and sharp cut-off of effective resistance even at the highest tested radiation fluence. The inter-strip capacitance complies with the technical specification required before irradiation and no radiation-induced degradation was observed. A summary of ATLAS12 sensors tests is presented including a comparison of results from different irradiation sites. The measured characteristics are compared with the previous prototype of the sensor design, ATLAS07.

Development of Lateral Flow Immunochromatographic Strips for Micropollutant Screening Using Colorants of Aptamer-Functionalized Nanogold Particles, Part II: Experimental Verification with Aflatoxin B1 and Chloramphenicol.

PubMed

Zhang, Shan; Zhao, Shuai; Wang, Sai; Liu, Jiahui; Dong, Yiyang

2018-05-09

Lateral flow immunochromatographic strips based on colorants of aptamer-functionalized nanogold particles weredeveloped for the detection of micropollutants aflatoxin B1 (AFB1) and chloramphenicol (CAP). The lateral flow immunochromatographic strip was based on a competitive reaction of thiolated-aptamer between micropollutants and bio-DNA probe-streptavidin as capture material immobilized at the test line. General crucial parameters that might influence the sensitivity have been systematically investigated. To test the effectiveness and applicability of the optimized conditions, two structurally unrelated micropollutants, that is, AFB1 and CAP, were chosen for detection. In the present study, lateral flow immunochromatographic strips for AFB1 and CAP analysis by combining the high selectivity and affinity of aptamers with the unique optical properties of nanogold in municipal water samples were reported for the first time. With the optimized conditions, the immunochromatographic strip showed a visual LOD of 10 ppb and a quantitative LOD of 1.05 ppb using an immunochromatographic reader for AFB1 detection and a quantitative LOD of 63.4 ppb using an immunochromatographic reader for CAP detection. Furthermore, the sensitive strip provided a good linear detection range of approximately 0-50 ppm for AFB1 detection and a wider liner detection range of approximately 0-160 ppm for CAP detection. Moreover, the immunochromatographic strip provided recovery rates for water samples of 90-110% in the AFB1 analysis and 84-108% in the CAP analysis. The results demonstrated that the immunochromatographic strip has excellent potential for wide applicability and verified that the strip methods for the optimized conditions are applicable to a variety of micropollutants. The lateral flow immunochromatographic strip could be used as a simple, rapid, and efficient screening tool for rapid on-site detection of a variety of micropollutants.

Glucose-Driven Fuel Cell Constructed from Enzymes and Filter Paper

ERIC Educational Resources Information Center

Ge, Jun; Schirhagl, Romana; Zare, Richard N.

2011-01-01

A glucose-driven enzymatic filter-paper fuel cell is described. A strip of filter paper coated with carbon nanotubes and the glucose oxidase enzyme functions as the anode of the enzyme fuel cell. Another strip of filter paper coated with carbon nanotubes and the laccase enzyme functions as the cathode. Between the anode and the cathode, a third…

Theoretical Investigation of the Interfacial Reactions during Hot-Dip Galvanizing of Steel

NASA Astrophysics Data System (ADS)

Mandal, G. K.; Balasubramaniam, R.; Mehrotra, S. P.

2009-03-01

In the modern galvanizing line, as soon as the steel strip enters the aluminum-containing zinc bath, two reactions occur at the strip and the liquid-zinc alloy interface: (1) iron rapidly dissolves from the strip surface, raising the iron concentration in the liquid phase at the strip-liquid interface; and (2) aluminum forms a stable aluminum-iron intermetallic compound layer at the strip-coating interface due to its greater affinity toward iron. The main objective of this study is to develop a simple and realistic mathematical model for better understanding of the kinetics of galvanizing reactions at the strip and the liquid-zinc alloy interface. In the present study, a model is proposed to simulate the effect of various process parameters on iron dissolution in the bath, as well as, aluminum-rich inhibition layer formation at the substrate-coating interface. The transient-temperature profile of the immersed strip is predicted based on conductive and convective heat-transfer mechanisms. The inhibition-layer thickness at the substrate-coating interface is predicted by assuming the cooling path of the immersed strip consists of a series of isothermal holds of infinitesimal time-step. The influence of galvanizing reaction is assessed by considering nucleation and growth mechanisms at each hold time, which is used to estimate the total effect of the immersion time on the formation mechanism of the inhibition layer. The iron- dissolution model is developed based on well established principles of diffusion taking into consideration the area fraction covered by the intermetallic on the strip surface during formation of the inhibition layer. The model can be effectively used to monitor the dross formation in the bath by optimizing the process parameters. Theoretical predictions are compared with the findings of other researchers. Simulated results are in good agreement with the theoretical and experimental observation carried out by other investigators.

Measurement of transepidermal water loss (TEWL) in cats with experimental skin barrier dysfunction using a closed chamber system.

PubMed

Momota, Yutaka; Shimada, Kenichiro; Gin, Azusa; Matsubara, Takako; Azakami, Daigo; Ishioka, Katsumi; Nakamura, Yuka; Sako, Toshinori

2016-10-01

A closed chamber evaporimeter is suitable for measuring transepidermal water loss (TEWL) in cats because of the compact device size, tolerance to sudden movement and short measuring time. TEWL is a representative parameter for skin barrier dysfunction, which is one of the clinical signs of atopic dermatitis in humans and dogs. Measurement of feline TEWL has been reported, but applicability of this parameter has not been validated. The aims of this study were to determine if tape stripping is a valid experimental model in cats for studying TEWL and to determine if a closed chambered system is a suitable measurement tool for cats. Ten clinically normal cats. In order to evaluate variation of the measured values, TEWL was measured at the right and left side of the three clipped regions (axillae, lateral thigh and groin). Subsequently, TEWL was measured using sequential tape stripping of the stratum corneum as a model of acute barrier disruption. The variations between both sides of the three regions showed no significant difference. Sequential tape stripping was associated with increasing values for TEWL. Feline TEWL was shown to reflect changes in the skin barrier in an experimental model using a closed chamber system and has the potential for evaluating skin barrier function in cats with skin diseases. © 2016 ESVD and ACVD.

Damage tolerance of woven graphite-epoxy buffer strip panels

NASA Technical Reports Server (NTRS)

Kennedy, John M.

1990-01-01

Graphite-epoxy panels with S glass buffer strips were tested in tension and shear to measure their residual strengths with crack-like damage. The buffer strips were regularly spaced narrow strips of continuous S glass. Panels were made with a uniweave graphite cloth where the S glass buffer material was woven directly into the cloth. Panels were made with different width and thickness buffer strips. The panels were loaded to failure while remote strain, strain at the end of the slit, and crack opening displacement were monitoring. The notched region and nearby buffer strips were radiographed periodically to reveal crack growth and damage. Except for panels with short slits, the buffer strips arrested the propagating crack. The strength (or failing strain) of the panels was significantly higher than the strength of all-graphite panels with the same length slit. Panels with wide, thick buffer strips were stronger than panels with thin, narrow buffer strips. A shear-lag model predicted the failing strength of tension panels with wide buffer strips accurately, but over-estimated the strength of the shear panels and the tension panels with narrow buffer strips.

Numerical procedure to determine geometric view factors for surfaces occluded by cylinders

NASA Technical Reports Server (NTRS)

Sawyer, P. L.

1978-01-01

A numerical procedure was developed to determine geometric view factors between connected infinite strips occluded by any number of infinite circular cylinders. The procedure requires a two-dimensional cross-sectional model of the configuration of interest. The two-dimensional model consists of a convex polygon enclosing any number of circles. Each side of the polygon represents one strip, and each circle represents a circular cylinder. A description and listing of a computer program based on this procedure are included in this report. The program calculates geometric view factors between individual strips and between individual strips and the collection of occluding cylinders.

Microstructure Engineering in Hot Strip Mills, Part 1 of 2: Integrated mathematical Model

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

J.K. Brimacombe; I.V. Samaraseker; E.B. Hawbolt

1998-09-30

This report describes the work of developing an integrated model used to predict the thermal history, deformation, roll forces, microstructural evaluation and mechanical properties of steel strip in a hot-strip mill. This achievement results from a join research effort that is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. DOE and fifteen North American steel makers.

Cranial biomechanics of Diplodocus (Dinosauria, Sauropoda): testing hypotheses of feeding behaviour in an extinct megaherbivore

NASA Astrophysics Data System (ADS)

Young, Mark T.; Rayfield, Emily J.; Holliday, Casey M.; Witmer, Lawrence M.; Button, David J.; Upchurch, Paul; Barrett, Paul M.

2012-08-01

Sauropod dinosaurs were the largest terrestrial herbivores and pushed at the limits of vertebrate biomechanics and physiology. Sauropods exhibit high craniodental diversity in ecosystems where numerous species co-existed, leading to the hypothesis that this biodiversity is linked to niche subdivision driven by ecological specialisation. Here, we quantitatively investigate feeding behaviour hypotheses for the iconic sauropod Diplodocus. Biomechanical modelling, using finite element analysis, was used to examine the performance of the Diplodocus skull. Three feeding behaviours were modelled: muscle-driven static biting, branch stripping and bark stripping. The skull was found to be `over engineered' for static biting, overall experiencing low stress with only the dentition enduring high stress. When branch stripping, the skull, similarly, is under low stress, with little appreciable difference between those models. When simulated for bark stripping, the skull experiences far greater stresses, especially in the teeth and at the jaw joint. Therefore, we refute the bark-stripping hypothesis, while the hypotheses of branch stripping and/or precision biting are both consistent with our findings, showing that branch stripping is a biomechanically plausible feeding behaviour for diplodocids. Interestingly, in all simulations, peak stress is observed in the premaxillary-maxillary `lateral plates', supporting the hypothesis that these structures evolved to dissipate stress induced while feeding. These results lead us to conclude that the aberrant craniodental form of Diplodocus was adapted for food procurement rather than resisting high bite forces.

Efficient hybrid evolutionary algorithm for optimization of a strip coiling process

NASA Astrophysics Data System (ADS)

Pholdee, Nantiwat; Park, Won-Woong; Kim, Dong-Kyu; Im, Yong-Taek; Bureerat, Sujin; Kwon, Hyuck-Cheol; Chun, Myung-Sik

2015-04-01

This article proposes an efficient metaheuristic based on hybridization of teaching-learning-based optimization and differential evolution for optimization to improve the flatness of a strip during a strip coiling process. Differential evolution operators were integrated into the teaching-learning-based optimization with a Latin hypercube sampling technique for generation of an initial population. The objective function was introduced to reduce axial inhomogeneity of the stress distribution and the maximum compressive stress calculated by Love's elastic solution within the thin strip, which may cause an irregular surface profile of the strip during the strip coiling process. The hybrid optimizer and several well-established evolutionary algorithms (EAs) were used to solve the optimization problem. The comparative studies show that the proposed hybrid algorithm outperformed other EAs in terms of convergence rate and consistency. It was found that the proposed hybrid approach was powerful for process optimization, especially with a large-scale design problem.

Evaluating the effect of different vegetative filter strip designs on sediment movement in an agricultural watershed using LISEM, Iowa, USA

NASA Astrophysics Data System (ADS)

Luquin Oroz, Eduardo; Cruse, Rick; Baartman, Jantiene; Keesstra, Saskia

2016-04-01

Although restoration of native vegetation in vulnerable areas would decrease soil loss, this approach is not feasible in communities that base their income on agriculture. However, an alternative exists: strategically placing a small percentage of vegetative filter strips (VFS) within agriculture fields for erosion control. Factors influencing their effectiveness are shallow conditions, vegetation type, filter strip width, slope, soil type, and rainfall characteristics. Generally, the first few meters of the strip are where most sediments deposit. For slopes higher than 10%, effectiveness decreases with increasing slope gradient. Usually, high rainfall intensity and sediment load in overland flow decrease vegetative filter strips' effectiveness. Nowadays, Iowa (USA), experiences increasingly stronger rainstorms; climate change is expected to increase rainfall erosive forces between 16 to 58%. Thus, there is a need to obtain new insights about strip design and its influence on sediment dynamics. Therefore, the objective of this study is to analyze strip design (width) impact on soil and water movement. To do so, different strip widths (no strips, 1.5, 3, 5, 7.5 and 10 meters wide) were analyzed under four rainfall intensities (increments of 10, 25, 50 and 75%) The event-based, hydrological and soil erosion model LISEM was used to simulate different scenarios. The model has been calibrated with data from 3-ha 'Interim 1' watershed, which is part of Walnut Creek (Iowa, USA). During a single event with sediment load, on July 18th 2010, intensities reached up to 80 mm/h. Two different land covers exist: (i) perennial vegetation, which has prairie vegetation covering patches and strips; and (ii) row crop agriculture where corn and soybeans are the main two crops in the area. Based on the different combination of widths and intensities, 24 scenarios were generated. At the moment, the model is on the final part of the calibration; scenario results will be presented on the poster.

Nano-solenoid: helicoid carbon-boron nitride hetero-nanotube

NASA Astrophysics Data System (ADS)

Zhang, Zi-Yue; Miao, Chunyang; Guo, Wanlin

2013-11-01

As a fundamental element of a nanoscale passive circuit, a nano-inductor is proposed based on a hetero-nanotube consisting of a spiral carbon strip and a spiral boron nitride strip. It is shown by density functional theory associated with nonequilibrium Green function calculations that the nanotube exhibits attractive transport properties tunable by tube chirality, diameter, component proportion and connection manner between the two strips, with excellent `OFF' state performance and high current on the order of 10-100 μA. All the hetero-nanotubes show negative differential resistance. The transmission peaks of current are absolutely derived from the helicoid carbon strips or C-BN boundaries, giving rise to a spiral current analogous with an energized nano-solenoid. According to Ampere's Law, the energized nano-solenoid can generate a uniform and tremendous magnetic field of more than 1 tesla, closing to that generated by the main magnet of medical nuclear magnetic resonance. Moreover, the magnitude of magnetic field can be easily modulated by bias voltage, providing great promise for a nano-inductor to realize electromagnetic conversion at the nanoscale.As a fundamental element of a nanoscale passive circuit, a nano-inductor is proposed based on a hetero-nanotube consisting of a spiral carbon strip and a spiral boron nitride strip. It is shown by density functional theory associated with nonequilibrium Green function calculations that the nanotube exhibits attractive transport properties tunable by tube chirality, diameter, component proportion and connection manner between the two strips, with excellent `OFF' state performance and high current on the order of 10-100 μA. All the hetero-nanotubes show negative differential resistance. The transmission peaks of current are absolutely derived from the helicoid carbon strips or C-BN boundaries, giving rise to a spiral current analogous with an energized nano-solenoid. According to Ampere's Law, the energized nano-solenoid can generate a uniform and tremendous magnetic field of more than 1 tesla, closing to that generated by the main magnet of medical nuclear magnetic resonance. Moreover, the magnitude of magnetic field can be easily modulated by bias voltage, providing great promise for a nano-inductor to realize electromagnetic conversion at the nanoscale. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr02914j

The Effect of Spray Strips on the Take-off Performance of a Model of a Flying-Boat Hull

NASA Technical Reports Server (NTRS)

Truscott, Starr

1935-01-01

The effect on the take-off performance of a model of the hull of a typical flying boat, Navy PH-1, of fitting spray strips of four different widths, each at three different angles, was determined by model tests in the NACA Tank. Spray strips of widths up to 3 percent of the beam improve the general performance at speeds near the hump and reduce the spray thrown. A downward angle of 30 degrees to 45 degrees in the neighborhood of the step seems most favorable for the reduction of the spray. The spray strips have a large effect in reducing the trimming moments at speeds near the hump speed, but have little effect on them at high speeds.

Quantum calculus of classical vortex images, integrable models and quantum states

NASA Astrophysics Data System (ADS)

Pashaev, Oktay K.

2016-10-01

From two circle theorem described in terms of q-periodic functions, in the limit q→1 we have derived the strip theorem and the stream function for N vortex problem. For regular N-vortex polygon we find compact expression for the velocity of uniform rotation and show that it represents a nonlinear oscillator. We describe q-dispersive extensions of the linear and nonlinear Schrodinger equations, as well as the q-semiclassical expansions in terms of Bernoulli and Euler polynomials. Different kind of q-analytic functions are introduced, including the pq-analytic and the golden analytic functions.

The water crisis in the gaza strip: prospects for resolution.

PubMed

Weinthal, E; Vengosh, A; Marei, A; Kloppmann, W

2005-01-01

Israel and the Palestinian Authority share the southern Mediterranean coastal aquifer. Long-term overexploitation in the Gaza Strip has resulted in a decreasing water table, accompanied by the degradation of its water quality. Due to high levels of salinity and nitrate and boron pollution, most of the ground water is inadequate for both domestic and agricultural consumption. The rapid rate of population growth in the Gaza Strip and dependence upon ground water as a single water source present a serious challenge for future political stability and economic development. Here, we integrate the results of geochemical studies and numerical modeling to postulate different management scenarios for joint management between Israel and the Palestinian Authority. The chemical and isotopic data show that most of the salinity phenomena in the Gaza Strip are derived from the natural flow of saline ground water from Israel toward the Gaza Strip. As a result, the southern coastal aquifer does not resemble a classic "upstream-downstream" dispute because Israel's pumping of the saline ground water reduces the salinization rates of ground water in the Gaza Strip. Simulation of different pumping scenarios using a monolayer, hydrodynamic, two-dimensional model (MARTHE) confirms the hypothesis that increasing pumping along the Gaza Strip border combined with a moderate reduction of pumping within the Gaza Strip would improve ground water quality within the Gaza Strip. We find that pumping the saline ground water for a source of reverse-osmosis desalination and then supplying the desalinated water to the Gaza Strip should be an essential component of a future joint management strategy between Israel and the Palestinian Authority.

Chaotic advection at large Péclet number: Electromagnetically driven experiments, numerical simulations, and theoretical predictions

NASA Astrophysics Data System (ADS)

Figueroa, Aldo; Meunier, Patrice; Cuevas, Sergio; Villermaux, Emmanuel; Ramos, Eduardo

2014-01-01

We present a combination of experiment, theory, and modelling on laminar mixing at large Péclet number. The flow is produced by oscillating electromagnetic forces in a thin electrolytic fluid layer, leading to oscillating dipoles, quadrupoles, octopoles, and disordered flows. The numerical simulations are based on the Diffusive Strip Method (DSM) which was recently introduced (P. Meunier and E. Villermaux, "The diffusive strip method for scalar mixing in two-dimensions," J. Fluid Mech. 662, 134-172 (2010)) to solve the advection-diffusion problem by combining Lagrangian techniques and theoretical modelling of the diffusion. Numerical simulations obtained with the DSM are in reasonable agreement with quantitative dye visualization experiments of the scalar fields. A theoretical model based on log-normal Probability Density Functions (PDFs) of stretching factors, characteristic of homogeneous turbulence in the Batchelor regime, allows to predict the PDFs of scalar in agreement with numerical and experimental results. This model also indicates that the PDFs of scalar are asymptotically close to log-normal at late stages, except for the large concentration levels which correspond to low stretching factors.

Differential photoelectric charging of nonconducting surfaces in space. [on sunlit strip

NASA Technical Reports Server (NTRS)

Pelizzari, M. A.; Criswell, D. R.

1978-01-01

The photoelectric charging caused by an infinitely long strip of sunlight across a nonconducting plane is studied by use of a model which contains an electrical cutoff radius, and the results of numerical calculations are presented. The model simulates charging of a sunlit area with dimensions equal to the strip's width, exposed to a plasma with a comparatively large Debye length. Uniform potential is quickly established on a uniformly sunlit strip as a result of charge redistribution by low-energy photoelectrons. The results are in accord with a theoretical surface conductivity derived for photoelectron sheaths above highly charged sunlit areas. The surface potential, which drops sharply across the sunlight-shadow boundary, is discussed.

Brief Report: Assessment of the Social-Emotional Profile in Children with Autism Spectrum Disorders Using a Novel Comic Strip Task

ERIC Educational Resources Information Center

Sivaratnam, Carmel S.; Cornish, Kim; Gray, Kylie M.; Howlin, Patricia; Rinehart, Nicole J.

2012-01-01

This study investigated whether the novel Comic Strip Task (CST) could be used to detect Theory-of-Mind impairments (ToM) in 4- to 8-year-old children with high functioning Autism Spectrum Disorders (ASD). Twelve children with either high-functioning autism or Asperger's Disorder and 12 typically-developing children completed the 21-item measure.…

A line transect model for aerial surveys

USGS Publications Warehouse

Quang, Pham Xuan; Lanctot, Richard B.

1991-01-01

We employ a line transect method to estimate the density of the common and Pacific loon in the Yukon Flats National Wildlife Refuge from aerial survey data. Line transect methods have the advantage of automatically taking into account “visibility bias” due to detectability difference of animals at different distances from the transect line. However, line transect methods must overcome two difficulties when applied to inaccurate recording of sighting distances due to high travel speeds, so that in fact only a few reliable distance class counts are available. We propose a unimodal detection function that provides an estimate of the effective area lost due to the blind strip, under the assumption that a line of perfect detection exists parallel to the transect line. The unimodal detection function can also be applied when a blind strip is absent, and in certain instances when the maximum probability of detection is less than 100%. A simple bootstrap procedure to estimate standard error is illustrated. Finally, we present results from a small set of Monte Carlo experiments.

AISI/DOE Advanced Process Control Program Vol. 3 of 6 Microstructure Engineering in Hot Strip Mills, Part 1 of 2: Integrated Mathematical Model

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

J.K. Brimacombe; I.V. Samarasekera; E.B. Hawbolt

1999-07-31

This report describes the work of developing an integrated model used to predict the thermal history, deformation, roll forces, microstructural evolution and mechanical properties of steel strip in a hot-strip mill. This achievement results from a joint research effort that is part of the American Iron and Steel Institute's (AIS) Advanced Process Control Program, a collaboration between the U.S. DOE and fifteen North American Steelmakers.

Interpretation of the human skin biotribological behaviour after tape stripping

PubMed Central

Pailler-Mattei, C.; Guerret-Piécourt, C.; Zahouani, H.; Nicoli, S.

2011-01-01

The present study deals with the modification of the human skin biotribological behaviour after tape stripping. The tape-stripping procedure consists in the sequential application and removal of adhesive tapes on the skin surface in order to remove stratum corneum (SC) layers, which electrically charges the skin surface. The skin electric charges generated by tape stripping highly change the skin friction behaviour by increasing the adhesion component of the skin friction coefficient. It has been proposed to rewrite the friction adhesion component as the sum of two terms: the first classical adhesion term depending on the intrinsic shear strength, τ0, and the second term depending on the electric shear strength, τelec. The experimental results allowed to estimate a numerical value of the electric shear strength τelec. Moreover, a plan capacitor model with a dielectric material inside was used to modelize the experimental system. This physical model permitted to evaluate the friction electric force and the electric shear strength values to calculate the skin friction coefficient after the tape stripping. The comparison between the experimental and the theoretical value of the skin friction coefficient after the tape stripping has shown the importance of the electric charges on skin biotribological behaviour. The static electric charges produced by tape stripping on the skin surface are probably able to highly modify the interaction of formulations with the skin surface and their spreading properties. This phenomenon, generally overlooked, should be taken into consideration as it could be involved in alteration of drug absorption. PMID:21227961

Interpretation of the human skin biotribological behaviour after tape stripping.

PubMed

Pailler-Mattei, C; Guerret-Piécourt, C; Zahouani, H; Nicoli, S

2011-07-06

The present study deals with the modification of the human skin biotribological behaviour after tape stripping. The tape-stripping procedure consists in the sequential application and removal of adhesive tapes on the skin surface in order to remove stratum corneum (SC) layers, which electrically charges the skin surface. The skin electric charges generated by tape stripping highly change the skin friction behaviour by increasing the adhesion component of the skin friction coefficient. It has been proposed to rewrite the friction adhesion component as the sum of two terms: the first classical adhesion term depending on the intrinsic shear strength, τ(0), and the second term depending on the electric shear strength, τ(elec). The experimental results allowed to estimate a numerical value of the electric shear strength τ(elec). Moreover, a plan capacitor model with a dielectric material inside was used to modelize the experimental system. This physical model permitted to evaluate the friction electric force and the electric shear strength values to calculate the skin friction coefficient after the tape stripping. The comparison between the experimental and the theoretical value of the skin friction coefficient after the tape stripping has shown the importance of the electric charges on skin biotribological behaviour. The static electric charges produced by tape stripping on the skin surface are probably able to highly modify the interaction of formulations with the skin surface and their spreading properties. This phenomenon, generally overlooked, should be taken into consideration as it could be involved in alteration of drug absorption.

The morphologic changes in lamellar bodies and intercorneocyte lipids after tape stripping and occlusion with a water vapor-impermeable membrane.

PubMed

Jiang, S; Koo, S W; Lee, S H

1998-03-01

It has been reported that artificial restoration of barrier function by a water vapor-impermeable membrane after tape stripping induces barrier abrogation in hairless mice, impeding rather than enhancing barrier recovery. To address this issue, we examined the morphologic changes in the epidermis after tape stripping and occlusion with a water vapor-impermeable membrane in murine skin. Male hairless mice were used for all studies of barrier perturbation and occlusion. Barrier disruption was achieved by repeated application of cellophane tape. Immediately after tape stripping the animals were wrapped in a tightly fitting water vapor-impermeable membrane. Transepidermal water loss (TEWL) was measured 20 min after tape stripping and 14, 24, 36, 48 and 60 h after occlusion. For electron microscopy the samples were treated with osmium tetroxide (OsO4) or ruthenium tetroxide (RuO4). When tape-stripped animals were wrapped in a water vapor-impermeable membrane, thereby preventing water flux, barrier function did not recover normally. These results demonstrate that an artificial block to TEWL with an impermeable membrane did not enhance barrier recovery. By electron microscopy many transitional cells and lacunae of various sizes were seen within the intercellular spaces of the stratum corneum after occlusion following tape stripping. Occlusion also caused alterations in both lipid lamellar membrane structures in the stratum corneum interstices and the lamellar bodies in the cytosol of granulocytes and transitional cells. Secreted lamellar body contents also appeared to be abnormal in the stratum corneum-stratum granulosum junction.

Shape control of NITINOL-reinforced composite beams

NASA Astrophysics Data System (ADS)

Baz, Amr M.; Chen, Tung-Huei; Ro, Jeng-Jong

1994-05-01

The shape of composite beams is controlled by sets of flat strips of a shape memory nickel-titanium alloy (NITINOL). A mathematical model is developed to describe the behavior of this class of SMART composites. The model describes the interaction between the elastic characteristics of the composite beams and the thermally- induced shape memory effect of the NITINOL strips. The effect of various activation strategies of the NITINOL strips on the shape of the composite beams is determined. The theoretical predictions of the model are validated experimentally using a fiberglass composite beam made of 8 plies of unidirectional BASF 5216 prepregs which are 9.75-cm wide and 21.20 cm long. The beams are provided with four NITINOL-55 strips which are 1.2 mm thick and 1.25 cm wide. The time response characteristics of the beam are monitored and compared with the corresponding theoretical characteristics. Close agreement is obtained between the theoretical predictions and the experimental results. The obtained results suggest the potential of the NITINOL strips in controlling the shape of composite beams without compromising their structural stiffness.

Thermodynamic Behavior Research Analysis of Twin-roll Casting Lead Alloy Strip Process

NASA Astrophysics Data System (ADS)

Jiang, Chengcan; Rui, Yannian

2017-03-01

The thermodynamic behavior of twin-roll casting (TRC) lead alloy strip process directly affects the forming of the lead strip, the quality of the lead strip and the production efficiency. However, there is little research on the thermodynamics of lead alloy strip at home and abroad. The TRC lead process is studied in four parameters: the pouring temperature of molten lead, the depth of molten pool, the roll casting speed, and the rolling thickness of continuous casting. Firstly, the thermodynamic model for TRC lead process is built. Secondly, the thermodynamic behavior of the TRC process is simulated with the use of Fluent. Through the thermodynamics research and analysis, the process parameters of cast rolling lead strip can be obtained: the pouring temperature of molten lead: 360-400 °C, the depth of molten pool: 250-300 mm, the roll casting speed: 2.5-3 m/min, the rolling thickness: 8-9 mm. Based on the above process parameters, the optimal parameters(the pouring temperature of molten lead: 375-390 °C, the depth of molten pool: 285-300 mm, the roll casting speed: 2.75-3 m/min, the rolling thickness: 8.5-9 mm) can be gained with the use of the orthogonal experiment. Finally, the engineering test of TRC lead alloy strip is carried out and the test proves the thermodynamic model is scientific, necessary and correct. In this paper, a detailed study on the thermodynamic behavior of lead alloy strip is carried out and the process parameters of lead strip forming are obtained through the research, which provide an effective theoretical guide for TRC lead alloy strip process.

HEAT TRANSFER FROM SURFACES OF NON-UNIFORM TEMPERATURE DISTRIBUTION. PART II. TURBULENT TRANSFER FROM ISOTHERMAL SPANWISE STRIPS ON A FLAT PLATE

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

Sogin, H.H.; Goldstein, R.J.

1960-02-01

Experiments were performed on mass transfer by forced convection from naphthalene strips on a flat plate to an air stream at ordinary temperature and pressure. Turbulence was induced in the boundary layer by means of a wire strip. In all cases there was a hydrodynamic starting length upstream of the strips. The ratio of this inert length to the total length was varied from about 0.80 to 0.96. The flow was practically incompressible with Reynolds number, based on the total length, varying from 175,000 to 486,000. The Schmidt number was 2.5. The experimental results fell in proximity to the Sebanmore » step function factor when they were reduced after the massmomentum analysis of Deissler and Loeffler for a surface of uniform vapor pressure. When Karman's formulation of the mass- momentum analogy was assumed, the data fell between the values predicted by the Seban and by the Rubesin expression for the step function factor. The results were well correlated by the Colburn analogy in conjunction with the Rubesin step function factor. (auth)« less

Crack propagation in functionally graded strip under thermal shock

NASA Astrophysics Data System (ADS)

Ivanov, I. V.; Sadowski, T.; Pietras, D.

2013-09-01

The thermal shock problem in a strip made of functionally graded composite with an interpenetrating network micro-structure of Al2O3 and Al is analysed numerically. The material considered here could be used in brake disks or cylinder liners. In both applications it is subjected to thermal shock. The description of the position-dependent properties of the considered functionally graded material are based on experimental data. Continuous functions were constructed for the Young's modulus, thermal expansion coefficient, thermal conductivity and thermal diffusivity and implemented as user-defined material properties in user-defined subroutines of the commercial finite element software ABAQUS™. The thermal stress and the residual stress of the manufacturing process distributions inside the strip are considered. The solution of the transient heat conduction problem for thermal shock is used for crack propagation simulation using the XFEM method. The crack length developed during the thermal shock is the criterion for crack resistance of the different graduation profiles as a step towards optimization of the composition gradient with respect to thermal shock sensitivity.

Rapidly solidified titanium alloys by melt overflow

NASA Technical Reports Server (NTRS)

Gaspar, Thomas A.; Bruce, Thomas J., Jr.; Hackman, Lloyd E.; Brasmer, Susan E.; Dantzig, Jonathan A.; Baeslack, William A., III

1989-01-01

A pilot plant scale furnace was designed and constructed for casting titanium alloy strips. The furnace combines plasma arc skull melting techniques with melt overflow rapid solidification technology. A mathematical model of the melting and casting process was developed. The furnace cast strip of a suitable length and width for use with honeycomb structures. Titanium alloys Ti-6Al-4V and Ti-14Al-21 Nb were successfully cast into strips. The strips were evaluated by optical metallography, microhardness measurements, chemical analysis, and cold rolling.

Impedance of strip-traveling waves on an elastic half space - Asymptotic solution

NASA Technical Reports Server (NTRS)

Crandall, S. H.; Nigam, A. K.

1973-01-01

The dynamic normal-load distribution across a strip that is required to maintain a plane progressive wave along its length is studied for the case where the strip is of infinite length and lies on the surface of a homogeneous isotropic elastic half space. This configuration is proposed as a preliminary idealized model for analyzing the dynamic interaction between soils and flexible foundations. The surface load distribution across the strip and the motion of the strip are related by a pair of dual integral equations. An asymptotic solution is obtained for the limiting case of small wavelength. The nature of this solution depends importantly on the propagation velocity of the strip-traveling wave in comparison with the Rayleigh wave speed, the shear wave speed and the dilatational wave speed. When the strip-traveling wave propagates faster than the Rayleigh wave speed, a pattern of trailing Rayleigh waves is shed from the strip. The limiting amplitude of the trailing waves is provided by the asymptotic solution.

Numerical Analysis of Effectiveness of Strengthening Concrete Slab in Tension of the Steel-Concrete Composite Beam Using Pretensioned CFRP Strips

NASA Astrophysics Data System (ADS)

Jankowiak, Iwona; Madaj, Arkadiusz

2017-12-01

One of the methods to increase the load carrying capacity of the reinforced concrete (RC) structure is its strengthening by using carbon fiber (CFRP) strips. There are two methods of strengthening using CFRP strips - passive method and active method. In the passive method a strip is applied to the concrete surface without initial strains, unlike in the active method a strip is initially pretensioned before its application. In the case of a steel-concrete composite beam, strips may be used to strengthen the concrete slab located in the tension zone (in the parts of beams with negative bending moments). The finite element model has been developed and validated by experimental tests to evaluate the strengthening efficiency of the composite girder with pretensioned CFRP strips applied to concrete slab in its tension zone.

A hybrid skull-stripping algorithm based on adaptive balloon snake models

NASA Astrophysics Data System (ADS)

Liu, Hung-Ting; Sheu, Tony W. H.; Chang, Herng-Hua

2013-02-01

Skull-stripping is one of the most important preprocessing steps in neuroimage analysis. We proposed a hybrid algorithm based on an adaptive balloon snake model to handle this challenging task. The proposed framework consists of two stages: first, the fuzzy possibilistic c-means (FPCM) is used for voxel clustering, which provides a labeled image for the snake contour initialization. In the second stage, the contour is initialized outside the brain surface based on the FPCM result and evolves under the guidance of the balloon snake model, which drives the contour with an adaptive inward normal force to capture the boundary of the brain. The similarity indices indicate that our method outperformed the BSE and BET methods in skull-stripping the MR image volumes in the IBSR data set. Experimental results show the effectiveness of this new scheme and potential applications in a wide variety of skull-stripping applications.

ENEL overall PWR plant models and neutronic integrated computing systems

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

Pedroni, G.; Pollachini, L.; Vimercati, G.

1987-01-01

To support the design activity of the Italian nuclear energy program for the construction of pressurized water reactors, the Italian Electricity Board (ENEL) needs to verify the design as a whole (that is, the nuclear steam supply system and balance of plant) both in steady-state operation and in transient. The ENEL has therefore developed two computer models to analyze both operational and incidental transients. The models, named STRIP and SFINCS, perform the analysis of the nuclear as well as the conventional part of the plant (the control system being properly taken into account). The STRIP model has been developed bymore » means of the French (Electricite de France) modular code SICLE, while SFINCS is based on the Italian (ENEL) modular code LEGO. STRIP validation was performed with respect to Fessenheim French power plant experimental data. Two significant transients were chosen: load step and total load rejection. SFINCS validation was performed with respect to Saint-Laurent French power plant experimental data and also by comparing the SFINCS-STRIP responses.« less

Poly-3-hydroxybutyrate strips seeded with regenerative cells are effective promoters of peripheral nerve repair.

PubMed

Schaakxs, Dominique; Kalbermatten, Daniel F; Pralong, Etienne; Raffoul, Wassim; Wiberg, Mikael; Kingham, Paul J

2017-03-01

Peripheral nerve injuries are often associated with loss of nerve tissue and require a graft to bridge the gap. Autologous nerve grafts are still the 'gold standard' in reconstructive surgery but have several disadvantages, such as sacrifice of a functional nerve, neuroma formation and loss of sensation at the donor site. Bioengineered grafts represent a promising approach to address this problem. In this study, poly-3-hydroxybutyrate (PHB) strips were used to bridge a 10 mm rat sciatic nerve gap and their effects on long-term (12 weeks) nerve regeneration were compared. PHB strips were seeded with different cell types, either primary Schwann cells (SCs) or SC-like differentiated adipose-derived stem cells (dASCs) suspended in a fibrin glue matrix. The control group was PHB and fibrin matrix without cells. Functional and morphological properties of the regenerated nerve were assessed using walking track analysis, EMGs, muscle weight ratios and muscle and nerve histology. The animals treated with PHB strips seeded with SCs or dASCs showed significantly better functional ability than the control group. This correlated with less muscle atrophy and greater axon myelination in the cell groups. These findings suggest that the PHB strip seeded with cells provides a beneficial environment for nerve regeneration. Furthermore, dASCs, which are abundant and easily accessible, constitute an attractive cell source for future applications of cell therapy for the clinical repair of traumatic nerve injuries. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Distillation and Air Stripping Designs for the Lunar Surface

NASA Technical Reports Server (NTRS)

Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

2009-01-01

Air stripping and distillation are two different gravity-based methods, which may be applied to the purification of wastewater on the lunar base. These gravity-based solutions to water processing are robust physical separation techniques, which may be advantageous to many other techniques for their simplicity in design and operation. The two techniques can be used in conjunction with each other to obtain high purity water. The components and feed compositions for modeling waste water streams are presented in conjunction with the Aspen property system for traditional stage distillation models and air stripping models. While the individual components for each of the waste streams will vary naturally within certain bounds, an analog model for waste water processing is suggested based on typical concentration ranges for these components. Target purity levels for the for recycled water are determined for each individual component based on NASA s required maximum contaminant levels for potable water Distillation processes are modeled separately and in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Optimum parameters such as reflux ratio, feed stage location, and processing rates are determined with respect to the power consumption of the process. Multistage distillation is evaluated for components in wastewater to determine the minimum number of stages necessary for each of 65 components in humidity condensate and urine wastewater mixed streams. Components of the wastewater streams are ranked by Henry s Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates.

Tidal stripping and the structure of dwarf galaxies in the Local Group

NASA Astrophysics Data System (ADS)

Fattahi, Azadeh; Navarro, Julio F.; Frenk, Carlos S.; Oman, Kyle A.; Sawala, Till; Schaller, Matthieu

2018-05-01

The shallow faint-end slope of the galaxy mass function is usually reproduced in Λ cold dark matter (ΛCDM) galaxy formation models by assuming that the fraction of baryons that turn into stars drops steeply with decreasing halo mass and essentially vanishes in haloes with maximum circular velocities Vmax < 20-30 km s-1. Dark-matter-dominated dwarfs should therefore have characteristic velocities of about that value, unless they are small enough to probe only the rising part of the halo circular velocity curve (i.e. half-mass radii, r1/2 ≪ 1 kpc). Many dwarfs have properties in disagreement with this prediction: they are large enough to probe their halo Vmax but their characteristic velocities are well below 20 km s-1. These `cold faint giants' (an extreme example is the recently discovered Crater 2 Milky Way satellite) can only be reconciled with our ΛCDM models if they are the remnants of once massive objects heavily affected by tidal stripping. We examine this possibility using the APOSTLE cosmological hydrodynamical simulations of the Local Group. Assuming that low-velocity-dispersion satellites have been affected by stripping, we infer their progenitor masses, radii, and velocity dispersions, and find them in remarkable agreement with those of isolated dwarfs. Tidal stripping also explains the large scatter in the mass discrepancy-acceleration relation in the dwarf galaxy regime: tides remove preferentially dark matter from satellite galaxies, lowering their accelerations below the amin ˜ 10-11 m s-2 minimum expected for isolated dwarfs. In many cases, the resulting velocity dispersions are inconsistent with the predictions from Modified Newtonian Dynamics, a result that poses a possibly insurmountable challenge to that scenario.

Cross Coating Weight Control by Electromagnetic Strip Stabilization at the Continuous Galvanizing Line of ArcelorMittal Florange

NASA Astrophysics Data System (ADS)

Guelton, Nicolas; Lopès, Catherine; Sordini, Henri

2016-08-01

In hot dip galvanizing lines, strip bending around the sink roll generates a flatness defect called crossbow. This defect affects the cross coating weight distribution by changing the knife-to-strip distance along the strip width and requires a significant increase in coating target to prevent any risk of undercoating. The already-existing coating weight control system succeeds in eliminating both average and skew coating errors but cannot do anything against crossbow coating errors. It has therefore been upgraded with a flatness correction function which takes advantage of the possibility of controlling the electromagnetic stabilizer. The basic principle is to split, for every gage scan, the coating weight cross profile of the top and bottom sides into two, respectively, linear and non-linear components. The linear component is used to correct the skew error by realigning the knives with the strip, while the non-linear component is used to distort the strip in the stabilizer in such a way that the strip is kept flat between the knives. Industrial evaluation is currently in progress but the first results have already shown that the strip can be significantly flattened between the knives and the production tolerances subsequently tightened without compromising quality.

Comparison of the relaxation effect in vitro of nitroglycerin vs. fenoterol on human myometrial strips.

PubMed

David, M; Hamann, C; Chen, F C; Bruch, L; Lichtenegger, W

2000-01-01

Substance dose-related comparison of relaxation effect of nitroglycerin (GTN) and the beta 2-mimetic substance fenoterol in human myometrial tissue. Test criterion is the isometric force development of isolated human myometrial strips. These muscle strips were removed from the lower uterine segment at cesarean section. Fenoterol in concentrations of 3 x 10(-8)-10(-5) mol/l or GTN in concentrations of 1.7 x 10(-8)-5.8 x 10(-4) mol/l were applied to the 2 x 2 x 10-mm strips, which were fixed and maintained in tissue baths. The curves were plotted on line. The integral or the "area under the curve" (AUC) served as the parameter for muscle strip activity. A total of 100 strips from 20 patients were used. GTN demonstrated a significant relaxation effect in the in vitro model on human myometrial strips from pregnant women already treated with oxytocin. The effect was able to be enhanced to a point where oxytocin-induced contractions were completely absent. A relatively clear connection was demonstrated between dose and effect whereby increased muscle relaxation resulted at increased concentrations. Compared to GTN application, muscle strip relaxation was less pronounced under fenoterol; a complete inhibition of myometrial activity was not achieved under fenoterol. With respect to relaxation of the myometrial tissue samples the NO donor GTN is at least as potent as the standard tocolytic agent fenoterol in the in vitro model.

Data-based hybrid tension estimation and fault diagnosis of cold rolling continuous annealing processes.

PubMed

Liu, Qiang; Chai, Tianyou; Wang, Hong; Qin, Si-Zhao Joe

2011-12-01

The continuous annealing process line (CAPL) of cold rolling is an important unit to improve the mechanical properties of steel strips in steel making. In continuous annealing processes, strip tension is an important factor, which indicates whether the line operates steadily. Abnormal tension profile distribution along the production line can lead to strip break and roll slippage. Therefore, it is essential to estimate the whole tension profile in order to prevent the occurrence of faults. However, in real annealing processes, only a limited number of strip tension sensors are installed along the machine direction. Since the effects of strip temperature, gas flow, bearing friction, strip inertia, and roll eccentricity can lead to nonlinear tension dynamics, it is difficult to apply the first-principles induced model to estimate the tension profile distribution. In this paper, a novel data-based hybrid tension estimation and fault diagnosis method is proposed to estimate the unmeasured tension between two neighboring rolls. The main model is established by an observer-based method using a limited number of measured tensions, speeds, and currents of each roll, where the tension error compensation model is designed by applying neural networks principal component regression. The corresponding tension fault diagnosis method is designed using the estimated tensions. Finally, the proposed tension estimation and fault diagnosis method was applied to a real CAPL in a steel-making company, demonstrating the effectiveness of the proposed method.

"Taste Strips" - a rapid, lateralized, gustatory bedside identification test based on impregnated filter papers.

PubMed

Landis, Basile Nicolas; Welge-Luessen, Antje; Brämerson, Annika; Bende, Mats; Mueller, Christian Albert; Nordin, Steven; Hummel, Thomas

2009-02-01

To elaborate normative values for a clinical psychophysical taste test ("Taste Strips"). The "Taste Strips" are a psychophysical chemical taste test. So far, no definitive normative data had been published and only a fairly small sample size has been investigated. In light of this shortcoming for this easy, reliable and quick taste testing device, we attempted to provide normative values suitable for the clinical use. Normative value acquisition study, multicenter study. The investigation involved 537 participants reporting a normal sense of smell and taste (318 female, 219 male, mean age 44 years, age range 18-87 years). The taste test was based on spoon-shaped filter paper strips ("Taste Strips") impregnated with the four (sweet, sour, salty, and bitter) taste qualities in four different concentrations. The strips were placed on the left or right side of the anterior third of the extended tongue, resulting in a total of 32 trials. With their tongue still extended, patients had to identify the taste from a list of four descriptors, i. e., sweet, sour, salty, and bitter (multiple forced-choice). To obtain an impression of overall gustatory function, the number of correctly identified tastes was summed up for a "taste score". Taste function decreased significantly with age. Women exhibited significantly higher taste scores than men which was true for all age groups. The taste score at the 10(th) percentile was selected as a cut-off value to distinguish normogeusia from hypogeusia. Results from a small series of patients with ageusia confirmed the clinical usefulness of the proposed normative values. The present data provide normative values for the "Taste Strips" based on over 500 subjects tested.

Acotiamide Hydrochloride, a Therapeutic Agent for Functional Dyspepsia, Enhances Acetylcholine-induced Contraction via Inhibition of Acetylcholinesterase Activity in Circular Muscle Strips of Guinea Pig Stomach.

PubMed

Ito, K; Kawachi, M; Matsunaga, Y; Hori, Y; Ozaki, T; Nagahama, K; Hirayama, M; Kawabata, Y; Shiraishi, Y; Takei, M; Tanaka, T

2016-04-01

Acotiamide is a first-in-class prokinetic drug approved in Japan for the treatment of functional dyspepsia. Given that acotiamide enhances gastric motility in conscious dogs and rats, we assessed the in vitro effects of this drug on the contraction of guinea pig stomach strips and on acetylcholinesterase (AChE) activity in stomach homogenate following fundus removal. We also investigated the serotonin 5-HT4 receptor agonist mosapride, dopamine D2 receptor and AChE inhibitor itopride, and representative AChE inhibitor neostigmine. Acotiamide (0.3 and 1 μM) and itopride (1 and 3 μM) significantly enhanced the contraction of gastric body strips induced by electrical field stimulation (EFS), but mosapride (1 and 10 μM) did not. Acotiamide and itopride significantly enhanced the contraction of gastric body and antrum strips induced by acetylcholine (ACh), but not that induced by carbachol (CCh). Neostigmine also significantly enhanced the contraction of gastric body strips induced by ACh, but not that by CCh. In contrast, mosapride failed to enhance contractions induced by either ACh or CCh in gastric antrum strips. Acotiamide exerted mixed inhibition of AChE, and the percentage inhibition of acotiamide (100 μM) against AChE activity was markedly reduced after the reaction mixture was dialyzed. In contrast, itopride exerted noncompetitive inhibition on AChE activity. These results indicate that acotiamide enhances ACh-dependent contraction in gastric strips of guinea pigs via the inhibition of AChE activity, and that it exerts mixed and reversible inhibition of AChE derived from guinea pig stomach. © Georg Thieme Verlag KG Stuttgart · New York.

Ionizing spectra of stars that lose their envelope through interaction with a binary companion: role of metallicity

NASA Astrophysics Data System (ADS)

Götberg, Y.; de Mink, S. E.; Groh, J. H.

2017-11-01

Understanding ionizing fluxes of stellar populations is crucial for various astrophysical problems including the epoch of reionization. Short-lived massive stars are generally considered as the main stellar sources. We examine the potential role of less massive stars that lose their envelope through interaction with a binary companion. Here, we focus on the role of metallicity (Z). For this purpose we used the evolutionary code MESA and created tailored atmosphere models with the radiative transfer code CMFGEN. We show that typical progenitors, with initial masses of 12 M⊙, produce hot and compact stars ( 4 M⊙, 60-80 kK, 1 R⊙). These stripped stars copiously produce ionizing photons, emitting 60-85% and 30-60% of their energy as HI and HeI ionizing radiation, for Z = 0.0001-0.02, respectively. Their output is comparable to what massive stars emit during their Wolf-Rayet phase, if we account for their longer lifetimes and the favorable slope of the initial mass function. Their relative importance for reionization may be further favored since they emit their photons with a time delay ( 20 Myr after birth in our fiducial model). This allows time for the dispersal of the birth clouds, allowing the ionizing photons to escape into the intergalactic medium. At low Z, we find that Roche stripping fails to fully remove the H-rich envelope, because of the reduced opacity in the subsurface layers. This is in sharp contrast with the assumption of complete stripping that is made in rapid population synthesis simulations, which are widely used to simulate the binary progenitors of supernovae and gravitational waves. Finally, we discuss the urgency to increase the observed sample of stripped stars to test these models and we discuss how our predictions can help to design efficient observational campaigns.

Probabilistic estimation of splitting coefficients of normal modes of the Earth, and their uncertainties, using an autoregressive technique

NASA Astrophysics Data System (ADS)

Pachhai, S.; Masters, G.; Laske, G.

2017-12-01

Earth's normal-mode spectra are crucial to studying the long wavelength structure of the Earth. Such observations have been used extensively to estimate "splitting coefficients" which, in turn, can be used to determine the three-dimensional velocity and density structure. Most past studies apply a non-linear iterative inversion to estimate the splitting coefficients which requires that the earthquake source is known. However, it is challenging to know the source details, particularly for big events as used in normal-mode analyses. Additionally, the final solution of the non-linear inversion can depend on the choice of damping parameter and starting model. To circumvent the need to know the source, a two-step linear inversion has been developed and successfully applied to many mantle and core sensitive modes. The first step takes combinations of the data from a single event to produce spectra known as "receiver strips". The autoregressive nature of the receiver strips can then be used to estimate the structure coefficients without the need to know the source. Based on this approach, we recently employed a neighborhood algorithm to measure the splitting coefficients for an isolated inner-core sensitive mode (13S2). This approach explores the parameter space efficiently without any need of regularization and finds the structure coefficients which best fit the observed strips. Here, we implement a Bayesian approach to data collected for earthquakes from early 2000 and more recent. This approach combines the data (through likelihood) and prior information to provide rigorous parameter values and their uncertainties for both isolated and coupled modes. The likelihood function is derived from the inferred errors of the receiver strips which allows us to retrieve proper uncertainties. Finally, we apply model selection criteria that balance the trade-offs between fit (likelihood) and model complexity to investigate the degree and type of structure (elastic and anelastic) required to explain the data.

Experimental and modelling study of the effect of airflow orientation with respect to strip electrode on ozone production of surface dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Mikeš, J.; Pekárek, S.; Soukup, I.

2016-11-01

This study examines the effect of airflow orientation with respect to the strip active electrode on concentration of ozone and nitrogen dioxide produced in a planar generator based on the surface dielectric barrier discharge. The orientation of the airflow was tested in parallel and perpendicular with respect to the strips. It was found that in the investigated range of average discharge power, the ozone concentration increases approximately by 25% when airflow was oriented in parallel with respect to the strips in comparison with perpendicular orientation of the airflow. Similarly the increase of nitrogen dioxide concentration was observed for parallel orientation of the airflow with respect to the strips in comparison with the perpendicular orientation of the airflow. Within the range of wavelengths from 250 to 1100 nm, the changes of intensities of spectral lines associated with airflow orientation have been observed. A 3D numerical model describing ion trajectories and airflow patterns have also been developed.

Finite element modeling simulation-assisted design of integrated microfluidic chips for heavy metal ion stripping analysis

NASA Astrophysics Data System (ADS)

Hong, Ying; Zou, Jianhua; Ge, Gang; Xiao, Wanyue; Gao, Ling; Shao, Jinjun; Dong, Xiaochen

2017-10-01

In this article, a transparent integrated microfluidic device composed of a 3D-printed thin-layer flow cell (3D-PTLFC) and an S-shaped screen-printed electrode (SPE) has been designed and fabricated for heavy metal ion stripping analysis. A finite element modeling (FEM) simulation is employed to optimize the shape of the electrode, the direction of the inlet pipeline, the thin-layer channel height and the sample flow rate to enhance the electron-enrichment efficiency for stripping analysis. The results demonstrate that the S-shaped SPE configuration matches the channel in 3D-PTLFC perfectly for the anodic stripping behavior of the heavy metal ions. Under optimized conditions, a wide linear range of 1-80 µg l-1 is achieved for Pb2+ detection with a limit of 0.3 µg l-1 for the microfluidic device. Thus, the obtained integrated microfluidic device proves to be a promising approach for heavy metal ions stripping analysis with low cost and high performance.

Reconstruction of 2D PET data with Monte Carlo generated system matrix for generalized natural pixels

NASA Astrophysics Data System (ADS)

Vandenberghe, Stefaan; Staelens, Steven; Byrne, Charles L.; Soares, Edward J.; Lemahieu, Ignace; Glick, Stephen J.

2006-06-01

In discrete detector PET, natural pixels are image basis functions calculated from the response of detector pairs. By using reconstruction with natural pixel basis functions, the discretization of the object into a predefined grid can be avoided. Here, we propose to use generalized natural pixel reconstruction. Using this approach, the basis functions are not the detector sensitivity functions as in the natural pixel case but uniform parallel strips. The backprojection of the strip coefficients results in the reconstructed image. This paper proposes an easy and efficient way to generate the matrix M directly by Monte Carlo simulation. Elements of the generalized natural pixel system matrix are formed by calculating the intersection of a parallel strip with the detector sensitivity function. These generalized natural pixels are easier to use than conventional natural pixels because the final step from solution to a square pixel representation is done by simple backprojection. Due to rotational symmetry in the PET scanner, the matrix M is block circulant and only the first blockrow needs to be stored. Data were generated using a fast Monte Carlo simulator using ray tracing. The proposed method was compared to a listmode MLEM algorithm, which used ray tracing for doing forward and backprojection. Comparison of the algorithms with different phantoms showed that an improved resolution can be obtained using generalized natural pixel reconstruction with accurate system modelling. In addition, it was noted that for the same resolution a lower noise level is present in this reconstruction. A numerical observer study showed the proposed method exhibited increased performance as compared to a standard listmode EM algorithm. In another study, more realistic data were generated using the GATE Monte Carlo simulator. For these data, a more uniform contrast recovery and a better contrast-to-noise performance were observed. It was observed that major improvements in contrast recovery were obtained with MLEM when the correct system matrix was used instead of simple ray tracing. The correct modelling was the major cause of improved contrast for the same background noise. Less important factors were the choice of the algorithm (MLEM performed better than ART) and the basis functions (generalized natural pixels gave better results than pixels).

Innovative and water based stripping approach for thick and bulk photoresists

NASA Astrophysics Data System (ADS)

Rudolph, Matthias; Schumann, Dirk; Thrun, Xaver; Esche, Silvio; Hohle, Christoph

2014-10-01

The usage of phase fluid based stripping agents to remove photoresists from silicon substrates was studied. Photoresists are required for many silicon based technologies such as MEMS patterning, 3D-Integration or frontend and backend of line semiconductor applications [1]. Although the use of resists is very common, their successful integration often depends on the ability to remove the resist after certain processing steps. On the one hand the resist is changing during subsequent process steps that can cause a thermally activated cross-linking which increases the stripping complexity. Resist removal is also challenging after the formation of a hard polymer surface layer during plasma or implant processes which is called skin or crust [2]. On the other hand the choice of stripping chemistry is often limited due to the presence of functional materials such as metals which can be damaged by aggressive stripping chemistries [3].

Percutaneous Vein Occlusion with Small Intestinal Submucosa: An Experimental Pilot Study in Swine and Sheep

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

Kim, Man Deuk; Hoppe, Hanno; Pavcnik, Dusan, E-mail: pavcnikd@ohsu.edu

2007-07-15

Purpose. The objective of this study was to investigate the feasibility, outcomes, and amount of small intestinal submucosa (SIS) material needed for embolization of jugular vein (JV) in a swine and sheep model. Our hypothesis was that SIS would cause vein occlusion. Materials and Methods. The external JVs (EJV) in swine (n = 6) and JVs in sheep (n = 6) were occluded with SIS fan-folded compressed strips. After percutaneous puncture of the peripheral portion of the EJV or JV, a TIPS set was used to exit their lumen centrally through the skin. The SIS strips were delivered into themore » isolated venous segment with a pull-through technique via a 10-Fr sheath. Follow-up venograms were done immediately after placement and at the time of sacrifice at 1 or 3 months. Gross examinations focused on the EJV or JV and their surrounding structures. Specimens were evaluated by histology. Results. SIS strip(s) placement was successful in all cases, with immediate vein occlusion seen in 23 of 24 veins (95.8%). All EJVs treated with two strips and all JVs treated with three or four strips remained closed on 1- and 3-month follow-up venograms. Two EJVs treated with one strip and one JV treated with two strips were partially patent on venograms at 1 and 3 months. There has been one skin inflammatory reaction. Necropsies revealed excluded EJV or JV segments with SIS incorporation into the vein wall. Histology demonstrated various stages of SIS remodeling with fibrocytes, fibroblasts, endothelial cells, capillaries, and inflammatory cells. Conclusion. We conclude that EJV and JV ablation with SIS strips using percutaneous exit catheterization is feasible and effective in animal models. Further exploration of SIS as vein ablation material is recommended.« less

Analysis of a unidirectional, symmetric buffer strip laminate with damage

NASA Technical Reports Server (NTRS)

Dharani, L. R.; Goree, J. G.

1984-01-01

A method for predicting the fracture behavior of hybrid buffer strip laminates is presented in which the classical shear-lag model is used to represent the shear stress distribution between adjacent fibers. The method is demonstrated by applying it to a notched graphite/epoxy laminate, and the results show clearly the manner in which the most efficient combination of buffer strip properties can be selected in order to arrest the crack. The ultimate failure stress of the laminate is plotted vs the buffer strip width. It is shown that in the case of graphite-epoxy and S-glass epoxy laminates, the optimum buffer strip spacing to width ratio should be about four to one.

Fluorimetric Mercury Test Strips with Suppressed "Coffee Stains" by a Bio-inspired Fabrication Strategy.

PubMed

Qiao, Yuchun; Shang, Jizhen; Li, Shuying; Feng, Luping; Jiang, Yao; Duan, Zhiqiang; Lv, Xiaoxia; Zhang, Chunxian; Yao, Tiantian; Dong, Zhichao; Zhang, Yu; Wang, Hua

2016-11-04

A fluorimetric Hg 2+ test strip has been developed using a lotus-inspired fabrication method for suppressing the "coffee stains" toward the uniform distribution of probe materials through creating a hydrophobic drying pattern for fast solvent evaporation. The test strips were first loaded with the model probes of fluorescent gold-silver nanoclusters and then dried in vacuum on the hydrophobic pattern. On the one hand, here, the hydrophobic constraining forces from the lotus surface-like pattern could control the exterior transport of dispersed nanoclusters on strips leading to the minimized "coffee stains". On the other hand, the vacuum-aided fast solvent evaporation could boost the interior Marangoni flow of probe materials on strips to expect the further improved probe distribution on strips. High aqueous stability and enhanced fluorescence of probes on test strips were realized by the hydrophilic treatment with amine-derivatized silicane. A test strips-based fluorimetry has thereby been developed for probing Hg 2+ ions in wastewater, showing the detection performances comparable to the classic instrumental analysis ones. Such a facile and efficient fabrication route for the bio-inspired suppression of "coffee stains" on test strips may expand the scope of applications of test strips-based "point-of-care" analysis methods or detection devices in the biomedical and environmental fields.

Degree of Phosphorus Saturation and Soil Phosphorus Thresholds in an Ultisol Amended with Triple Superphosphate and Phosphate Rocks

PubMed Central

Gikonyo, E. W.; Zaharah, A. R.; Hanafi, M. M.; Anuar, A. R.

2011-01-01

Soil phosphorus (P) release capability could be assessed through the degree of P saturation (DPS). Our main objective was to determine DPS and, hence, P threshold DPS values of an Ultisol treated with triple superphosphate (TSP), Gafsa phosphate rocks (GPR), or Christmas Island phosphate rocks (CIPR), plus or minus manure. P release was determined by the iron oxide—impregnated paper strip (strip P), while DPS was determined from ammonium oxalate—extractable aluminum (Al), iron (Fe), and P. Soils were sampled from a closed incubation study involving soils treated with TSP, GPR, and CIPR at 0–400 mg P kg-1, and a field study where soils were fertilized with the same P sources at 100–300 kg P ha-1 plus or minus manure. The DPS was significantly influenced by P source x P rate, P source x manure (incubated soils), and by P source x P rate x time (field-sampled soils). Incubated soil results indicated that both initial P and total strip P were related to DPS by exponential functions: initial strip P = 1.38exp0.18DPS, R2 = 0.82** and total strip P = 8.01exp0.13DPS, R2 = 0.65**. Initial strip P was linearly related to total P; total P = 2.45, initial P + 8.41, R2 = 0.85**. The threshold DPS value established was about 22% (incubated soil). Field soils had lower DPS values <12% and strip P was related to initial DPS and average DPS in exponential functions: strip P = 2.6exp0.44DPS, R2 = 0.77** and strip P = 1.1DPS2 — 2.4DPS + 6.2, R2 = 0.58**, respectively. The threshold values were both at ≈8% and P release was 11–14 mg P kg-1. Results are evident that DPS can be used to predict P release, but the threshold values are environmentally sensitive; hence, recommendations should be based on field trials. PMID:21805012

Degree of phosphorus saturation and soil phosphorus thresholds in an ultisol amended with triple superphosphate and phosphate rocks.

PubMed

Gikonyo, E W; Zaharah, A R; Hanafi, M M; Anuar, A R

2011-07-28

Soil phosphorus (P) release capability could be assessed through the degree of P saturation (DPS). Our main objective was to determine DPS and, hence, P threshold DPS values of an Ultisol treated with triple superphosphate (TSP), Gafsa phosphate rocks (GPR), or Christmas Island phosphate rocks (CIPR), plus or minus manure. P release was determined by the iron oxide-impregnated paper strip (strip P), while DPS was determined from ammonium oxalate-extractable aluminum (Al), iron (Fe), and P. Soils were sampled from a closed incubation study involving soils treated with TSP, GPR, and CIPR at 0-400 mg P kg-1, and a field study where soils were fertilized with the same P sources at 100-300 kg P ha-1 plus or minus manure. The DPS was significantly influenced by P source x P rate, P source x manure (incubated soils), and by P source x P rate x time (field-sampled soils). Incubated soil results indicated that both initial P and total strip P were related to DPS by exponential functions: initial strip P = 1.38exp0.18DPS, R2 = 0.82** and total strip P = 8.01exp0.13DPS, R2 = 0.65**. Initial strip P was linearly related to total P; total P = 2.45, initial P + 8.41, R2 = 0.85**. The threshold DPS value established was about 22% (incubated soil). Field soils had lower DPS values <12% and strip P was related to initial DPS and average DPS in exponential functions: strip P = 2.6exp0.44DPS, R2 = 0.77** and strip P = 1.1DPS2 ¨C 2.4DPS + 6.2, R2 = 0.58**, respectively. The threshold values were both approximately equal to 8% and P release was 11-14 mg P kg-1. Results are evident that DPS can be used to predict P release, but the threshold values are environmentally sensitive; hence, recommendations should be based on field trials.

Field-dependent critical state of high-Tc superconducting strip simultaneously exposed to transport current and perpendicular magnetic field

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

Xue, Cun; He, An; Yong, Huadong

We present an exact analytical approach for arbitrary field-dependent critical state of high-T{sub c} superconducting strip with transport current. The sheet current and flux-density profiles are derived by solving the integral equations, which agree with experiments quite well. For small transport current, the approximate explicit expressions of sheet current, flux-density and penetration depth for the Kim model are derived based on the mean value theorem for integration. We also extend the results to the field-dependent critical state of superconducting strip in the simultaneous presence of applied field and transport current. The sheet current distributions calculated by the Kim model agreemore » with experiments better than that by the Bean model. Moreover, the lines in the I{sub a}-B{sub a} plane for the Kim model are not monotonic, which is quite different from that the Bean model. The results reveal that the maximum transport current in thin superconducting strip will decrease with increasing applied field which vanishes for the Bean model. The results of this paper are useful to calculate ac susceptibility and ac loss.« less

Chaotic advection at large Péclet number: Electromagnetically driven experiments, numerical simulations, and theoretical predictions

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

Figueroa, Aldo; Meunier, Patrice; Villermaux, Emmanuel

2014-01-15

We present a combination of experiment, theory, and modelling on laminar mixing at large Péclet number. The flow is produced by oscillating electromagnetic forces in a thin electrolytic fluid layer, leading to oscillating dipoles, quadrupoles, octopoles, and disordered flows. The numerical simulations are based on the Diffusive Strip Method (DSM) which was recently introduced (P. Meunier and E. Villermaux, “The diffusive strip method for scalar mixing in two-dimensions,” J. Fluid Mech. 662, 134–172 (2010)) to solve the advection-diffusion problem by combining Lagrangian techniques and theoretical modelling of the diffusion. Numerical simulations obtained with the DSM are in reasonable agreement withmore » quantitative dye visualization experiments of the scalar fields. A theoretical model based on log-normal Probability Density Functions (PDFs) of stretching factors, characteristic of homogeneous turbulence in the Batchelor regime, allows to predict the PDFs of scalar in agreement with numerical and experimental results. This model also indicates that the PDFs of scalar are asymptotically close to log-normal at late stages, except for the large concentration levels which correspond to low stretching factors.« less

A static model of a Sendzimir mill for use in shape control

NASA Astrophysics Data System (ADS)

Gunawardene, G. W. D. M.

The design of shape control systems is an area of current interest in the steel industry. Shape is defined as the internal stress distribution resulting from a transverse variation in the reduction of the strip thickness. The object of shape control is to adjust the mill so that the rolled strip is free from internal stresses. Both static and dynamic models of the mill are required for the control system design.The subject of this thesis is the static model of the Sendzimir cold rolling mill, which is a 1-2-3-4 type cluster mill. The static model derived enables shape profiles to be calculated for a given set of actuator positions, and is used to generate the steady state mill gains. The method of calculation of these shape profiles is discussed. The shape profiles obtained for different mill schedules are plotted against the distance across the strip. The corresponding mill gains are calculated and these relate the shape changes to the actuator changes. These mill gains are presented in the form of a square matrix, obtained by measuring shape at eight points across the strip.

Optimization of Stripping Voltammetric Sensor by a Back Propagation Artificial Neural Network for the Accurate Determination of Pb(II) in the Presence of Cd(II).

PubMed

Zhao, Guo; Wang, Hui; Liu, Gang; Wang, Zhiqiang

2016-09-21

An easy, but effective, method has been proposed to detect and quantify the Pb(II) in the presence of Cd(II) based on a Bi/glassy carbon electrode (Bi/GCE) with the combination of a back propagation artificial neural network (BP-ANN) and square wave anodic stripping voltammetry (SWASV) without further electrode modification. The effects of Cd(II) in different concentrations on stripping responses of Pb(II) was studied. The results indicate that the presence of Cd(II) will reduce the prediction precision of a direct calibration model. Therefore, a two-input and one-output BP-ANN was built for the optimization of a stripping voltammetric sensor, which considering the combined effects of Cd(II) and Pb(II) on the SWASV detection of Pb(II) and establishing the nonlinear relationship between the stripping peak currents of Pb(II) and Cd(II) and the concentration of Pb(II). The key parameters of the BP-ANN and the factors affecting the SWASV detection of Pb(II) were optimized. The prediction performance of direct calibration model and BP-ANN model were tested with regard to the mean absolute error (MAE), root mean square error (RMSE), average relative error (ARE), and correlation coefficient. The results proved that the BP-ANN model exhibited higher prediction accuracy than the direct calibration model. Finally, a real samples analysis was performed to determine trace Pb(II) in some soil specimens with satisfactory results.

Numerical and theoretical evaluations of AC losses for single and infinite numbers of superconductor strips with direct and alternating transport currents in external AC magnetic field

NASA Astrophysics Data System (ADS)

Kajikawa, K.; Funaki, K.; Shikimachi, K.; Hirano, N.; Nagaya, S.

2010-11-01

AC losses in a superconductor strip are numerically evaluated by means of a finite element method formulated with a current vector potential. The expressions of AC losses in an infinite slab that corresponds to a simple model of infinitely stacked strips are also derived theoretically. It is assumed that the voltage-current characteristics of the superconductors are represented by Bean's critical state model. The typical operation pattern of a Superconducting Magnetic Energy Storage (SMES) coil with direct and alternating transport currents in an external AC magnetic field is taken into account as the electromagnetic environment for both the single strip and the infinite slab. By using the obtained results of AC losses, the influences of the transport currents on the total losses are discussed quantitatively.

Flat Plate Boundary Layer Stimulation Using Trip Wires and Hama Strips

NASA Astrophysics Data System (ADS)

Peguero, Charles; Henoch, Charles; Hrubes, James; Fredette, Albert; Roberts, Raymond; Huyer, Stephen

2017-11-01

Water tunnel experiments on a flat plate at zero angle of attack were performed to investigate the effect of single roughness elements, i.e., trip wires and Hama strips, on the transition to turbulence. Boundary layer trips are traditionally used in scale model testing to force a boundary layer to transition from laminar to turbulent flow at a single location to aid in scaling of flow characteristics. Several investigations of trip wire effects exist in the literature, but there is a dearth of information regarding the influence of Hama strips on the flat plate boundary layer. The intent of this investigation is to better understand the effects of boundary layer trips, particularly Hama strips, and to investigate the pressure-induced drag of both styles of boundary layer trips. Untripped and tripped boundary layers along a flat plate at a range of flow speeds were characterized with multiple diagnostic measurements in the NUWC/Newport 12-inch water tunnel. A wide range of Hama strip and wire trip thicknesses were used. Measurements included dye flow visualization, direct skin friction and parasitic drag force, boundary layer profiles using LDV, wall shear stress fluctuations using hot film anemometry, and streamwise pressure gradients. Test results will be compared to the CFD and boundary layer model results as well as the existing body of work. Conclusions, resulting in guidance for application of Hama strips in model scale experiments and non-dimensional predictions of pressure drag will be presented.

Optimization of Focusing by Strip and Pixel Arrays

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

Burke, G J; White, D A; Thompson, C A

Professor Kevin Webb and students at Purdue University have demonstrated the design of conducting strip and pixel arrays for focusing electromagnetic waves [1, 2]. Their key point was to design structures to focus waves in the near field using full wave modeling and optimization methods for design. Their designs included arrays of conducting strips optimized with a downhill search algorithm and arrays of conducting and dielectric pixels optimized with the iterative direct binary search method. They used a finite element code for modeling. This report documents our attempts to duplicate and verify their results. We have modeled 2D conducting stripsmore » and both conducting and dielectric pixel arrays with moment method and FDTD codes to compare with Webb's results. New designs for strip arrays were developed with optimization by the downhill simplex method with simulated annealing. Strip arrays were optimized to focus an incident plane wave at a point or at two separated points and to switch between focusing points with a change in frequency. We also tried putting a line current source at the focus point for the plane wave to see how it would work as a directive antenna. We have not tried optimizing the conducting or dielectric pixel arrays, but modeled the structures designed by Webb with the moment method and FDTD to compare with the Purdue results.« less

The Origin of Dwarf Ellipticals in the Virgo Cluster

NASA Astrophysics Data System (ADS)

Boselli, A.; Boissier, S.; Cortese, L.; Gavazzi, G.

2008-02-01

We study the evolution of dwarf (LH < 109.6 LH⊙) star-forming and quiescent galaxies in the Virgo Cluster by comparing their UV to radio centimetric properties to the predictions of multizone chemospectrophotometric models of galaxy evolution especially tuned to take into account the perturbations induced by the interaction with the cluster intergalactic medium. Our models simulate one or multiple ram pressure stripping events and galaxy starvation. Models predict that all star-forming dwarf galaxies entering the cluster for the first time loose most, if not all, of their atomic gas content, quenching on short timescales (<=150 Myr) their activity of star formation. These dwarf galaxies soon become red and quiescent, gas metal-rich objects with spectrophotometric and structural properties similar to those of dwarf ellipticals. Young, low-luminosity, high surface brightness star-forming galaxies such as late-type spirals and BCDs are probably the progenitors of relatively massive dwarf ellipticals, while it is likely that low surface brightness Magellanic irregulars evolve into very low surface brightness quiescent objects hardly detectable in ground-based imaging surveys. The small number of dwarf galaxies with physical properties intermediate between those of star-forming and quiescent systems is consistent with a rapid (<1 Gyr) transitional phase between the two dwarf galaxy populations. These results, combined with statistical considerations, are consistent with the idea that most of the dwarf ellipticals dominating the faint end of the Virgo luminosity function were initially star-forming systems, accreted by the cluster and stripped of their gas by one or subsequent ram pressure stripping events.

The effects of whole-vault cranioplasty versus strip craniectomy on long-term neuropsychological outcomes in sagittal craniosynostosis.

PubMed

Hashim, Peter W; Patel, Anup; Yang, Jenny F; Travieso, Roberto; Terner, Jordan; Losee, Joseph E; Pollack, Ian; Jane, John; Jane, John; Kanev, Paul; Mayes, Linda; Duncan, Charles; Bridgett, David J; Persing, John A

2014-09-01

The optimal type of surgical management for isolated sagittal synostosis remains a source of significant debate. There is a paucity of data regarding possible differences in long-term neuropsychological outcomes following treatment with whole-vault cranioplasty or endoscopic strip craniectomy. This study provides the first comparative analysis examining the effects of the two techniques related to long-term intellectual functioning. A total of 70 patients were enrolled in this multicenter study, 29 of whom had previously undergone endoscopic strip craniectomy and 41 of whom had previously undergone whole-vault cranioplasty. All patients completed a battery of neurodevelopmental tests (Beery-Buktenica Developmental Test of Visual-Motor Integration, Wechsler Abbreviated Scale of Intelligence, and Wechsler Fundamentals) to evaluate various domains of neuropsychological function. In a group comparison of those treated before 6 months of age, whole-vault patients obtained higher scores relative to endoscopic strip craniectomy patients on visuomotor integration, full-scale intelligence quotient, verbal intelligence quotient, word reading, and reading comprehension (p < 0.05 for all). When compared against strip craniectomy performed before 3 months of age, the whole-vault group still showed significantly higher scores in verbal intelligence quotient, reading comprehension, and word reading (p < 0.05 for all). The type of surgical intervention for isolated sagittal synostosis impacts long-term neuropsychological outcomes. Patients undergoing early whole-vault cranioplasty attained higher intelligence quotient and achievement scores relative to those undergoing strip craniectomy. Surgical management with whole-vault cranioplasty performed before 6 months of age provides the most favorable long-term intellectual outcomes in patients with isolated sagittal synostosis. Therapeutic, II.

Semi-Analytic Galaxies - I. Synthesis of environmental and star-forming regulation mechanisms

NASA Astrophysics Data System (ADS)

Cora, Sofía A.; Vega-Martínez, Cristian A.; Hough, Tomás; Ruiz, Andrés N.; Orsi, Álvaro; Muñoz Arancibia, Alejandra M.; Gargiulo, Ignacio D.; Collacchioni, Florencia; Padilla, Nelson D.; Gottlöber, Stefan; Yepes, Gustavo

2018-05-01

We present results from the semi-analytic model of galaxy formation SAG applied on the MULTIDARK simulation MDPL2. SAG features an updated supernova (SN) feedback scheme and a robust modelling of the environmental effects on satellite galaxies. This incorporates a gradual starvation of the hot gas halo driven by the action of ram pressure stripping (RPS), that can affect the cold gas disc, and tidal stripping (TS), which can act on all baryonic components. Galaxy orbits of orphan satellites are integrated providing adequate positions and velocities for the estimation of RPS and TS. The star formation history and stellar mass assembly of galaxies are sensitive to the redshift dependence implemented in the SN feedback model. We discuss a variant of our model that allows to reconcile the predicted star formation rate density at z ≳ 3 with the observed one, at the expense of an excess in the faint end of the stellar mass function at z = 2. The fractions of passive galaxies as a function of stellar mass, halo mass and the halo-centric distances are consistent with observational measurements. The model also reproduces the evolution of the main sequence of star forming central and satellite galaxies. The similarity between them is a result of the gradual starvation of the hot gas halo suffered by satellites, in which RPS plays a dominant role. RPS of the cold gas does not affect the fraction of quenched satellites but it contributes to reach the right atomic hydrogen gas content for more massive satellites (M⋆ ≳ 1010 M⊙).

Fluorimetric Mercury Test Strips with Suppressed “Coffee Stains” by a Bio-inspired Fabrication Strategy

PubMed Central

Qiao, Yuchun; Shang, Jizhen; Li, Shuying; Feng, Luping; Jiang, Yao; Duan, Zhiqiang; Lv, Xiaoxia; Zhang, Chunxian; Yao, Tiantian; Dong, Zhichao; Zhang, Yu; Wang, Hua

2016-01-01

A fluorimetric Hg2+ test strip has been developed using a lotus-inspired fabrication method for suppressing the “coffee stains” toward the uniform distribution of probe materials through creating a hydrophobic drying pattern for fast solvent evaporation. The test strips were first loaded with the model probes of fluorescent gold-silver nanoclusters and then dried in vacuum on the hydrophobic pattern. On the one hand, here, the hydrophobic constraining forces from the lotus surface-like pattern could control the exterior transport of dispersed nanoclusters on strips leading to the minimized “coffee stains”. On the other hand, the vacuum-aided fast solvent evaporation could boost the interior Marangoni flow of probe materials on strips to expect the further improved probe distribution on strips. High aqueous stability and enhanced fluorescence of probes on test strips were realized by the hydrophilic treatment with amine-derivatized silicane. A test strips-based fluorimetry has thereby been developed for probing Hg2+ ions in wastewater, showing the detection performances comparable to the classic instrumental analysis ones. Such a facile and efficient fabrication route for the bio-inspired suppression of “coffee stains” on test strips may expand the scope of applications of test strips-based “point-of-care” analysis methods or detection devices in the biomedical and environmental fields. PMID:27812040

A new strips tracker for the upgraded ATLAS ITk detector

NASA Astrophysics Data System (ADS)

David, C.

2018-01-01

The ATLAS detector has been designed and developed to function in the environment of the present Large Hadron Collider (LHC). At the next-generation tracking detector proposed for the High Luminosity LHC (HL-LHC), the so-called ATLAS Phase-II Upgrade, the fluences and radiation levels will be higher by as much as a factor of ten. The new sub-detectors must thus be faster, of larger area, more segmented and more radiation hard while the amount of inactive material should be minimized and the power supply to the front-end systems should be increased. For those reasons, the current inner tracker of the ATLAS detector will be fully replaced by an all-silicon tracking system that consists of a pixel detector at small radius close to the beam line and a large area strip tracker surrounding it. This document gives an overview of the design of the strip inner tracker (Strip ITk) and summarises the intensive R&D activities performed over the last years by the numerous institutes within the Strips ITk collaboration. These studies are accompanied with a strong prototyping effort to contribute to the optimisation of the Strip ITk's structure and components. This effort culminated recently in the release of the ATLAS Strips ITk Technical Design Report (TDR).

Host Galaxy Spectra of Stripped SN from the Palomar Transient Factory: SN Progenitor Diagnostics and the SN-GRB Connection

NASA Astrophysics Data System (ADS)

Modjaz, Maryam; Gal-Yam, Avishay; Arcavi, Iair

2012-02-01

Stripped core-collapse supernovae (Stripped SNe) are powerful cosmic engines that energize and enrich the ISM and that sometimes accompany GRBs, but the exact mass and metallicity range of their massive progenitors is not known, nor the detailed physics of the explosion. We propose to continue conducting the first uniform and statistically significant study of host galaxies of 60 stripped SNe from the same innovative, homogeneous and galaxy-unbiased survey Palomar Transient Factory in order to determine the environmental conditions that influence the various kinds of massive stellar deaths. By obtaining spectra of the immediate host environments of our sample of stripped SN, we will (1) measure local abundances in order to differentiate between the two progenitor scenarios for stripped SN and (2) derive stellar population ages, masses and star formation histories via detailed stellar population synthesis models. Moreover, we will test if natal chemical abundance has effects on basic SN characteristics, such as peak luminosity. Any observed trends will have ramifications on SN and GRB explosion models and imply important demographic SN considerations. Our dataset will provide a crucial complimentary set to host galaxy studies of long-duration GRBs and pave the way for host studies of transients and SN found via upcoming surveys such as LSST.

Host Galaxy Spectra of Stripped SN from the Palomar Transient Factory: SN Progenitor Diagnostics and the SN-GRB Connection

NASA Astrophysics Data System (ADS)

Modjaz, Maryam; Gal-Yam, Avishay; Arcavi, Iair

2011-02-01

Stripped core-collapse supernovae (Stripped SN) are powerful cosmic engines that energize and enrich the ISM and that sometimes accompany GRBs, but the exact mass and metallicity range of their massive progenitors is not known, nor the detailed physics of the explosion. With the harvest of 50 stripped SN from the innovative survey Palomar Transient Factory, we propose to conduct the first uniform and statistically significant study with SN from the same homogeneous and galaxy-unbiased survey in order to determine the environmental conditions that influence the various kinds of massive stellar deaths. By obtaining spectra of the immediate host environments of our sample of stripped SN, we will (1) measure local abundances in order to differentiate between the two progenitor scenarios for stripped SN and (2) derive stellar population ages, masses and star formation histories via detailed stellar population synthesis models. Moreover, we will test if natal chemical abundance has effects on basic SN characteristics, such as peak luminosity. Any observed trends will have ramifications on SN and GRB explosion models and imply important demographic SN considerations. Our dataset will provide a crucial complimentary set to host galaxy studies of long-duration GRBs and pave the way for host studies of transients and SN found via upcoming surveys such as LSST.

Design of BAs-AlN monolayered honeycomb heterojunction structures: A first-principles study

NASA Astrophysics Data System (ADS)

Camacho-Mojica, Dulce C.; López-Urías, Florentino

2016-04-01

BAs and AlN are semiconductor materials with an indirect and direct gap respectively in the bulk phase. Recently, electronic calculations have demonstrated that a single-layer or few layers of BAs and AlN exhibit a graphite-like structure with interesting electronic properties. In this work, infinite sheets single-layer heterojunction structures based on alternated strips with honeycomb BAs and AlN layers are investigated using first-principles density functional theory calculations. Optimized geometries, density of states, band-gaps, formation energies, and wave functions are studied for different strip widths joined along zigzag and armchair edges. Results in optimized heterojunction geometries revealed that BAs narrow strips exhibit a corrugation effect due to a lattice mismatch. It was found that zigzag heterojunctions are more energetically favored than armchair heterojunctions. Furthermore, the formation energy presents a maximum at the point where the heterojunction becomes a planar structure. Electronic charge density results yielded a more ionic behavior in Alsbnd N bonds than the Bsbnd As bonds in accordance with monolayer results. It was observed that the conduction band minimum for both heterojunctions exhibit confined states located mainly at the entire AlN strips whereas the valence band maximum exhibits confined states located mainly at BAs strips. We expect that the present investigation will motivate more experimental and theoretical studies on new layered materials made of III-V semiconductors.

Regenerating the last strips in strip-cuttings in Virginia pine

Treesearch

Edward I. Sucoff

1961-01-01

When Virginia pine (Pinus virginiana Mill.) is logged, even in pure stands, its natural regeneration is not readily achieved. This is because the species is intolerant and commonly functions in nature as a transitory pioneer; hardwoods become established under its canopy and tend to dominate the reproduction after the pine is cut. Experience indicates that the most...

Nanoscale Test Strips for Multiplexed Blood Analysis

NASA Technical Reports Server (NTRS)

Chan, Eugene

2015-01-01

A critical component of the DNA Medicine Institute's Reusable Handheld Electrolyte and Lab Technology for Humans (rHEALTH) sensor are nanoscale test strips, or nanostrips, that enable multiplexed blood analysis. Nanostrips are conceptually similar to the standard urinalysis test strip, but the strips are shrunk down a billionfold to the microscale. Each nanostrip can have several sensor pads that fluoresce in response to different targets in a sample. The strips carry identification tags that permit differentiation of a specific panel from hundreds of other nanostrip panels during a single measurement session. In Phase I of the project, the company fabricated, tested, and demonstrated functional parathyroid hormone and vitamin D nanostrips for bone metabolism, and thrombin aptamer and immunoglobulin G antibody nanostrips. In Phase II, numerous nanostrips were developed to address key space flight-based medical needs: assessment of bone metabolism, immune response, cardiac status, liver metabolism, and lipid profiles. This unique approach holds genuine promise for space-based portable biodiagnostics and for point-of-care (POC) health monitoring and diagnostics here on Earth.

The effect of a periodic absorptive strip arrangement on an interior sound field in a room.

PubMed

Park, Joo-Bae; Grosh, Karl; Kim, Yang-Hann

2005-02-01

In this paper we study the effect of periodically arranged sound absorptive strips on the mean acoustic potential energy density distribution of a room. The strips are assumed to be attached on the room's surface of interest. In order to determine their effect, the mean acoustic potential energy density variation is evaluated as the function of a ratio of the strip's arrangement period to wavelength. The evaluation demonstrates that the mean acoustic potential energy density tends to converge. In addition, a comparison with a case in which absorptive materials completely cover the selected absorptive plane shows that a periodic arrangement that uses only half of the absorptive material can be more efficient than a total covering, unless the frequency of interest does not coincide with the room's resonant frequencies. Consequently, the results prove that the ratio of the arrangement period to the wavelength plays an important role in the effectiveness of a periodic absorptive strip arrangement to minimize a room's mean acoustic potential energy density.

Rough-to-smooth transition of an equilibrium neutral constant stress layer

NASA Technical Reports Server (NTRS)

Logan, E., Jr.; Fichtl, G. H.

1975-01-01

Purpose of research on rough-to-smooth transition of an equilibrium neutral constant stress layer is to develop a model for low-level atmospheric flow over terrains of abruptly changing roughness, such as those occurring near the windward end of a landing strip, and to use the model to derive functions which define the extent of the region affected by the roughness change and allow adequate prediction of wind and shear stress profiles at all points within the region. A model consisting of two bounding logarithmic layers and an intermediate velocity defect layer is assumed, and dimensionless velocity and stress distribution functions which meet all boundary and matching conditions are hypothesized. The functions are used in an asymptotic form of the equation of motion to derive a relation which governs the growth of the internal boundary layer. The growth relation is used to predict variation of surface shear stress.

Development and experimental validation of a frying model to estimate acrylamide levels in French fries.

PubMed

Palazoğlu, T K; Gökmen, V

2008-04-01

In this study, a numerical model was developed to simulate frying of potato strips and estimate acrylamide levels in French fries. Heat and mass transfer parameters determined during frying of potato strips and the formation and degradation kinetic parameters of acrylamide obtained with a sugar-asparagine model system were incorporated within the model. The effect of reducing sugar content (0.3 to 2.15 g/100 g dry matter), strip thickness (8.5 x 8.5 mm and 10 x 10 mm), and frying time (3, 4, 5, and 6 min) and temperature (150, 170, and 190 degrees C) on resultant acrylamide level in French fries was investigated both numerically and experimentally. The model appeared to closely estimate the acrylamide contents, and thereby may potentially save considerable time, money, and effort during the stages of process design and optimization.

Reactive extraction of lactic acid with trioctylamine/methylene chloride/n-hexane

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

Han, D.H.; Hong, W.H.

The trioctylamine (TOA)/methylene chloride (MC)/n-hexane system was used as the extraction agent for the extraction of lactic acid. Curves of equilibrium and hydration were obtained at various temperatures and concentrations of TOA. A modified mass action model was proposed to interpret the equilibrium and the hydration curves. The reaction mechanism and the corresponding parameters which best represent the equilibrium data were estimated, and the concentration of water in the organic phase was predicted by inserting the parameters into the simple mathematical equation of the modified model. The concentration of MC and the change of temperature were important factors for themore » extraction and the stripping process. The stripping was performed by a simple distillation which was a combination of temperature-swing regeneration and diluent-swing regeneration. The type of inactive diluent has no influence on the stripping. The stripping efficiencies were about 70%.« less

Quantification of changes in skin hydration and sebum after tape stripping using infrared spectroscopy

NASA Astrophysics Data System (ADS)

Ezerskaia, A.; Pereira, S. F.; Urbach, H. P.; Varghese, B.

2017-02-01

Skin barrier function relies on well balanced water and lipid system of stratum corneum. Optimal hydration and oiliness levels are indicators of skin health and integrity. We demonstrate an accurate and sensitive depth profiling of stratum corneum sebum and hydration levels using short wave infrared spectroscopy in the spectral range around 1720 nm. We demonstrate that short wave infrared spectroscopic technique combined with tape stripping can provide morequantitative and more reliable skin barrier function information in the low hydration regime, compared to conventional biophysical methods.

/sup 45/Ca distribution and transport in saponin skinned vascular smooth muscle

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

Stout, M.A.; Diecke, F.P.

1983-04-01

/sup 45/Ca distribution and transport were studied in chemically skinned strips of caudal artery from Kyoto Wistar rats. Sarcolemmal membranes were made hyperpermeable by exposure for 60 min to solutions containing 0.1 mg/ml of saponin. Skinned helical strips responded with graded contractions to changes in ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid buffered free Ca solutions (10(-7) to 10(-5) M) and were sensitive to the Mg-ATP concentration. Tissues loaded in the presence of 10(-7) M Ca contracted in response to 10 mM caffeine. These experiments indicate the strips are skinned and possess a functional regulatory and contractile system and an intact Camore » sequestering system. /sup 45/Ca distributes in three compartments in skinned caudal artery strips. The Ca contents of two components are linear functions of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration and desaturate at rapid rates. They correspond to the extracellular and cytoplasmic spaces. A significantly smaller component releases Ca at comparatively slower rates. /sup 45/Ca uptake by the slow component consists of an ATP-dependent and an ATP-independent fraction. The /sup 45/Ca content of the ATP-dependent fraction is a function of the free Ca concentration and is independent of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration. Its content was enhanced by oxalate and was abolished by Triton X-100 skinning solutions. The ATP-independent component was not affected by Triton X-100 skinning and may represent Ca binding to cytoplasmic molecules and structures. The sequestered Ca was released with caffeine or Ca but not by epinephrine. The observations indicate that the sarcoplasmic reticulum and mitochondria of vascular smooth muscle strips skinned with saponin retain their functional integrity after saponin skinning.« less

Importance of functional and metabolic impairments in the characterization of the C-26 murine model of cancer cachexia

PubMed Central

Murphy, Kate T.; Chee, Annabel; Trieu, Jennifer; Naim, Timur; Lynch, Gordon S.

2012-01-01

SUMMARY Cancer cachexia describes the progressive skeletal muscle wasting and weakness that is associated with many cancers. It impairs quality of life and accounts for >20% of all cancer-related deaths. The main outcome that affects quality of life and mortality is loss of skeletal muscle function and so preclinical models should exhibit similar functional impairments in order to maximize translational outcomes. Mice bearing colon-26 (C-26) tumors are commonly used in cancer cachexia studies but few studies have provided comprehensive assessments of physiological and metabolic impairment, especially those factors that impact quality of life. Our aim was to characterize functional impairments in mildly and severely affected cachectic mice, and determine the suitability of these mice as a preclinical model. Metabolic abnormalities are also evident in cachectic patients and we investigated whether C-26-tumor-bearing mice had similar metabolic aberrations. Twelve-week-old CD2F1 mice received a subcutaneous injection of PBS (control) or C-26 tumor cells. After 18–20 days, assessments were made of grip strength, rotarod performance, locomotor activity, whole body metabolism, and contractile properties of tibialis anterior (TA) muscles (in situ) and diaphragm muscle strips (in vitro). Injection of C-26 cells reduced body and muscle mass, and epididymal fat mass. C-26-tumor-bearing mice exhibited lower grip strength and rotarod performance. Locomotor activity was impaired following C-26 injection, with reductions in movement distance, duration and speed compared with controls. TA muscles from C-26-tumor-bearing mice had lower maximum force (−27%) and were more susceptible to fatigue. Maximum specific (normalized) force of diaphragm muscle strips was reduced (−10%) with C-26 injection, and force during fatiguing stimulation was also lower. C-26-tumor-bearing mice had reduced carbohydrate oxidation and increased fat oxidation compared with controls. The range and consistency of functional and metabolic impairments in C-26-tumor-bearing mice confirm their suitability as a preclinical model for cancer cachexia. We recommend the use of these comprehensive functional assessments to maximize the translation of findings to more accurately identify effective treatments for cancer cachexia. PMID:22563056

Research on Modeling of Propeller in a Turboprop Engine

NASA Astrophysics Data System (ADS)

Huang, Jiaqin; Huang, Xianghua; Zhang, Tianhong

2015-05-01

In the simulation of engine-propeller integrated control system for a turboprop aircraft, a real-time propeller model with high-accuracy is required. A study is conducted to compare the real-time and precision performance of propeller models based on strip theory and lifting surface theory. The emphasis in modeling by strip theory is focused on three points as follows: First, FLUENT is adopted to calculate the lift and drag coefficients of the propeller. Next, a method to calculate the induced velocity which occurs in the ground rig test is presented. Finally, an approximate method is proposed to obtain the downwash angle of the propeller when the conventional algorithm has no solution. An advanced approximation of the velocities induced by helical horseshoe vortices is applied in the model based on lifting surface theory. This approximate method will reduce computing time and remain good accuracy. Comparison between the two modeling techniques shows that the model based on strip theory which owns more advantage on both real-time and high-accuracy can meet the requirement.

Research and Development Trend of Shape Control for Cold Rolling Strip

NASA Astrophysics Data System (ADS)

Wang, Dong-Cheng; Liu, Hong-Min; Liu, Jun

2017-09-01

Shape is an important quality index of cold rolling strip. Up to now, many problems in the shape control domain have not been solved satisfactorily, and a review on the research progress in the shape control domain can help to seek new breakthrough directions. In the past 10 years, researches and applications of shape control models, shape control means, shape detection technology, and shape control system have achieved significant progress. In the aspect of shape control models, the researches in the past improve the accuracy, speed and robustness of the models. The intelligentization of shape control models should be strengthened in the future. In the aspect of the shape control means, the researches in the past focus on the roll optimization, mill type selection, process optimization, local strip shape control, edge drop control, and so on. In the future, more attention should be paid to the coordination control of both strip shape and other quality indexes, and the refinement of control objective should be strengthened. In the aspects of shape detection technology and shape control system, some new types of shape detection meters and shape control systems are developed and have successfully industrial applications. In the future, the standardization of shape detection technology and shape control system should be promoted to solve the problem of compatibility. In general, the four expected development trends of shape control for cold rolling strip in the future are intelligentization, coordination, refinement, and standardization. The proposed research provides new breakthrough directions for improving shape quality.

Formula Gives Better Contact-Resistance Values

NASA Technical Reports Server (NTRS)

Lieneweg, Udo; Hannaman, David J.

1988-01-01

Lateral currents in contact strips taken into account. Four-terminal test structures added to intergrated circuits to enable measurement of interfacial resistivities of contacts between thin conducting layers. Thin-film model simplified quasi-two-dimensional potential model that accounts adequately for complicated three-dimensional, nonuniform current densitites. Effects of nonuniformity caused by lateral current flow in strips summarized in equivalent resistance Rs and voltage Vs.

Role of LOTR1 in Nutrient Transport through Organization of Spatial Distribution of Root Endodermal Barriers.

PubMed

Li, Baohai; Kamiya, Takehiro; Kalmbach, Lothar; Yamagami, Mutsumi; Yamaguchi, Katsushi; Shigenobu, Shuji; Sawa, Shinichiro; Danku, John M C; Salt, David E; Geldner, Niko; Fujiwara, Toru

2017-03-06

The formation of Casparian strips and suberin lamellae at the endodermis limits the free diffusion of nutrients and harmful substances via the apoplastic space between the soil solution and the stele in roots [1-3]. Casparian strips are ring-like lignin polymers deposited in the middle of anticlinal cell walls between endodermal cells and fill the gap between them [4-6]. Suberin lamellae are glycerolipid polymers covering the endodermal cells and likely function as a barrier to limit transmembrane movement of apoplastic solutes into the endodermal cells [7, 8]. However, the current knowledge on the formation of these two distinct endodermal barriers and their regulatory role in nutrient transport is still limited. Here, we identify an uncharacterized gene, LOTR1, essential for Casparian strip formation in Arabidopsis thaliana. The lotr1 mutants display altered localization of CASP1, an essential protein for Casparian strip formation [9], disrupted Casparian strips, ectopic suberization of endodermal cells, and low accumulation of shoot calcium (Ca). Degradation by expression of a suberin-degrading enzyme in the mutants revealed that the ectopic suberization at the endodermal cells limits Ca transport through the transmembrane pathway, thereby causing reduced Ca delivery to the shoot. Moreover, analysis of the mutants showed that suberin lamellae function as an apoplastic diffusion barrier to the stele at sites of lateral root emergence where Casparian strips are disrupted. Our findings suggest that the transmembrane pathway through unsuberized endodermal cells, rather than the sites of lateral root emergence, mediates the transport of apoplastic substances such as Ca into the xylem. Copyright © 2017 Elsevier Ltd. All rights reserved.

Subsonic and Supersonic Flutter Analysis of a Highly Tapered Swept-Wing Planform, Including Effects of Density Variation and Finite Wing Thickness, and Comparison with Experiments

NASA Technical Reports Server (NTRS)

Yates, Carson, Jr.

1967-01-01

The flutter characteristics of several wings with an aspect-ratio of 4.0, a taper ratio of 0.2, and a quarter-chord sweepback of 45 deg. have been investigated analytically for Mach numbers up to 2.0. The calculations were based on the modified-strip-analysis method, the subsonic-kernel-function method, piston theory, and quasi-steady second-order theory. Results of t h e analysis and comparisons with experiment indicated that: (1) Flutter speeds were accurately predicted by the modified strip analysis, although accuracy at t h e highest Mach numbers required the use of nonlinear aerodynamic theory (which accounts for effects of wing thickness) for the calculation of the aerodynamic parameters. (2) An abrupt increase of flutter-speed coefficient with increasing Mach number, observed experimentally in the transonic range, was also indicated by the modified strip analysis. (3) In the low supersonic range for some densities, a discontinuous variation of flutter frequency with Mach number was indicated by the modified strip analysis. An abrupt change of frequency appeared experimentally in the transonic range. (4) Differences in flutter-speed-coefficient levels obtained from tests at low supersonic Mach numbers in two wind tunnels were also predicted by the modified strip analysis and were shown to be caused primarily by differences in mass ratio. (5) Flutter speeds calculated by the subsonic-kernel-function method were in good agreement with experiment and with the results of the modified strip analysis. (6) Flutter speed obtained from piston theory and from quasi-steady second-order theory were higher than experimental values by at least 38 percent.

Using Comic Strip Conversations to Increase Social Satisfaction and Decrease Loneliness in Students with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Pierson, Melinda R.; Glaeser, Barbara C.

2007-01-01

Comic Strip Conversations have been used to improve the social skills of students on the autism spectrum. Research on the effectiveness of this strategy was extended to three lower elementary-aged male students diagnosed as exhibiting high-functioning autism. One elementary special education teacher and her 2 paraprofessionals used Comic Strip…

Photovoltaic Roofs

NASA Technical Reports Server (NTRS)

Drummond, R. W., Jr.; Shepard, N. F., Jr.

1984-01-01

Solar cells perform two functions: waterproofing roof and generating electricity. Sections through horizontal and slanting joints show overlapping modules sealed by L-section rubber strips and side-by-side modules sealed by P-section strips. Water seeping through seals of slanting joints drains along channels. Rooftop photovoltaic array used watertight south facing roof, replacing shingles, tar, and gravel. Concept reduces cost of residential solar-cell array.

[Effect of different therapy options on bronchial contraction in rats with modeled obstructive pulmonary disease].

PubMed

Kuzubova, N A; Fedin, A N; Lebedeva, E S; Platonova, I S

2014-09-01

In the model of chronic obstructive pulmonary disease, produced in rats by 60-day exposure to nitrogen dioxide, the effect of different options of combination therapy (corticosteroids, anticholinergics, adrenergic agonists) on the functional state of the bronchi was studied. The contractile activity of strips of the bronchi caused by nerve or smooth muscle stimulation was evaluated. Corticosteroid monotherapy resulted in deterioration of the functional state of the bronchial wall neuromuscular apparatus due to corticosteroid resistance, evolving under the influence of long-term exposure to nitrogen dioxide. Application of M-anticholinergic tiotropium had a beneficial effect on the functional state of the bronchi smooth muscles, leading to the full restoration of the bronchial wall contractile activity and removal the morphological manifestations of inflammatory lung tissue remodeling. Most effective in terms of impact on the functional state of the bronchial wall neuromuscular apparatus was corticosteroid therapy combined with M-cholinolytik or beta2-adrenoagonist.

Adequate model complexity for scenario analysis of VOC stripping in a trickling filter.

PubMed

Vanhooren, H; Verbrugge, T; Boeije, G; Demey, D; Vanrolleghem, P A

2001-01-01

Two models describing the stripping of volatile organic contaminants (VOCs) in an industrial trickling filter system are developed. The aim of the models is to investigate the effect of different operating conditions (VOC loads and air flow rates) on the efficiency of VOC stripping and the resulting concentrations in the gas and liquid phases. The first model uses the same principles as the steady-state non-equilibrium activated sludge model Simple Treat, in combination with an existing biofilm model. The second model is a simple mass balance based model only incorporating air and liquid and thus neglecting biofilm effects. In a first approach, the first model was incorporated in a five-layer hydrodynamic model of the trickling filter, using the carrier material design specifications for porosity, water hold-up and specific surface area. A tracer test with lithium was used to validate this approach, and the gas mixing in the filters was studied using continuous CO2 and O2 measurements. With the tracer test results, the biodegradation model was adapted, and it became clear that biodegradation and adsorption to solids can be neglected. On this basis, a simple dynamic mass balance model was built. Simulations with this model reveal that changing the air flow rate in the trickling filter system has little effect on the VOC stripping efficiency at steady state. However, immediately after an air flow rate change, quite high flux and concentration peaks of VOCs can be expected. These phenomena are of major importance for the design of an off-gas treatment facility.

Application of a SERS-based lateral flow immunoassay strip for the rapid and sensitive detection of staphylococcal enterotoxin B

NASA Astrophysics Data System (ADS)

Hwang, Joonki; Lee, Sangyeop; Choo, Jaebum

2016-06-01

A novel surface-enhanced Raman scattering (SERS)-based lateral flow immunoassay (LFA) biosensor was developed to resolve problems associated with conventional LFA strips (e.g., limits in quantitative analysis and low sensitivity). In our SERS-based biosensor, Raman reporter-labeled hollow gold nanospheres (HGNs) were used as SERS detection probes instead of gold nanoparticles. With the proposed SERS-based LFA strip, the presence of a target antigen can be identified through a colour change in the test zone. Furthermore, highly sensitive quantitative evaluation is possible by measuring SERS signals from the test zone. To verify the feasibility of the SERS-based LFA strip platform, an immunoassay of staphylococcal enterotoxin B (SEB) was performed as a model reaction. The limit of detection (LOD) for SEB, as determined with the SERS-based LFA strip, was estimated to be 0.001 ng mL-1. This value is approximately three orders of magnitude more sensitive than that achieved with the corresponding ELISA-based method. The proposed SERS-based LFA strip sensor shows significant potential for the rapid and sensitive detection of target markers in a simplified manner.A novel surface-enhanced Raman scattering (SERS)-based lateral flow immunoassay (LFA) biosensor was developed to resolve problems associated with conventional LFA strips (e.g., limits in quantitative analysis and low sensitivity). In our SERS-based biosensor, Raman reporter-labeled hollow gold nanospheres (HGNs) were used as SERS detection probes instead of gold nanoparticles. With the proposed SERS-based LFA strip, the presence of a target antigen can be identified through a colour change in the test zone. Furthermore, highly sensitive quantitative evaluation is possible by measuring SERS signals from the test zone. To verify the feasibility of the SERS-based LFA strip platform, an immunoassay of staphylococcal enterotoxin B (SEB) was performed as a model reaction. The limit of detection (LOD) for SEB, as determined with the SERS-based LFA strip, was estimated to be 0.001 ng mL-1. This value is approximately three orders of magnitude more sensitive than that achieved with the corresponding ELISA-based method. The proposed SERS-based LFA strip sensor shows significant potential for the rapid and sensitive detection of target markers in a simplified manner. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07243c

Leader-Follower Formation Control of UUVs with Model Uncertainties, Current Disturbances, and Unstable Communication

PubMed Central

Yan, Zheping; Xu, Da; Chen, Tao; Zhang, Wei; Liu, Yibo

2018-01-01

Unmanned underwater vehicles (UUVs) have rapidly developed as mobile sensor networks recently in the investigation, survey, and exploration of the underwater environment. The goal of this paper is to develop a practical and efficient formation control method to improve work efficiency of multi-UUV sensor networks. Distributed leader-follower formation controllers are designed based on a state feedback and consensus algorithm. Considering that each vehicle is subject to model uncertainties and current disturbances, a second-order integral UUV model with a nonlinear function is established using the state feedback linearized method under current disturbances. For unstable communication among UUVs, communication failure and acoustic link noise interference are considered. Two-layer random switching communication topologies are proposed to solve the problem of communication failure. For acoustic link noise interference, accurate representation of valid communication information and noise stripping when designing controllers is necessary. Effective communication topology weights are designed to represent the validity of communication information interfered by noise. Utilizing state feedback and noise stripping, sufficient conditions for design formation controllers are proposed to ensure UUV formation achieves consensus under model uncertainties, current disturbances, and unstable communication. The stability of formation controllers is proven by the Lyapunov-Razumikhin theorem, and the validity is verified by simulation results. PMID:29473919

Getting More Power from Your Flowers: Multi-Functional Flower Strips Enhance Pollinators and Pest Control Agents in Apple Orchards

PubMed Central

Wilby, Andrew; Sutton, Peter; Wäckers, Felix

2017-01-01

Flower strips are commonly recommended to boost biodiversity and multiple ecosystem services (e.g., pollination and pest control) on farmland. However, significant knowledge gaps remain regards the extent to which they deliver on these aims. Here, we tested the efficacy of flower strips that targeted different subsets of beneficial arthropods (pollinators and natural enemies) and their ecosystem services in cider apple orchards. Treatments included mixes that specifically targeted: (1) pollinators (‘concealed-nectar plants’); (2) natural enemies (‘open-nectar plants’); or (3) both groups concurrently (i.e., ‘multi-functional’ mix). Flower strips were established in alleyways of four orchards and compared to control alleyways (no flowers). Pollinator (e.g., bees) and natural enemy (e.g., parasitoid wasps, predatory flies and beetles) visitation to flower strips, alongside measures of pest control (aphid colony densities, sentinel prey predation), and fruit production, were monitored in orchards over two consecutive growing seasons. Targeted flower strips attracted either pollinators or natural enemies, whereas mixed flower strips attracted both groups in similar abundance to targeted mixes. Natural enemy densities on apple trees were higher in plots containing open-nectar plants compared to other treatments, but effects were stronger for non-aphidophagous taxa. Predation of sentinel prey was enhanced in all flowering plots compared to controls but pest aphid densities and fruit yield were unaffected by flower strips. We conclude that ‘multi-functional’ flower strips that contain flowering plant species with opposing floral traits can provide nectar and pollen for both pollinators and natural enemies, but further work is required to understand their potential for improving pest control services and yield in cider apple orchards. PMID:28930157

Preliminary Design and Evaluation of Portable Electronic Flight Progress Strips

NASA Technical Reports Server (NTRS)

Doble, Nathan A.; Hansman, R. John

2002-01-01

There has been growing interest in using electronic alternatives to the paper Flight Progress Strip (FPS) for air traffic control. However, most research has been centered on radar-based control environments, and has not considered the unique operational needs of the airport air traffic control tower. Based on an analysis of the human factors issues for control tower Decision Support Tool (DST) interfaces, a requirement has been identified for an interaction mechanism which replicates the advantages of the paper FPS (e.g., head-up operation, portability) but also enables input and output with DSTs. An approach has been developed which uses a Portable Electronic FPS that has attributes of both a paper strip and an electronic strip. The prototype flight strip system uses Personal Digital Assistants (PDAs) to replace individual paper strips in addition to a central management interface which is displayed on a desktop computer. Each PDA is connected to the management interface via a wireless local area network. The Portable Electronic FPSs replicate the core functionality of paper flight strips and have additional features which provide a heads-up interface to a DST. A departure DST is used as a motivating example. The central management interface is used for aircraft scheduling and sequencing and provides an overview of airport departure operations. This paper will present the design of the Portable Electronic FPS system as well as preliminary evaluation results.

Evaluation of substance P as a neurotransmitter in equine jejunum.

PubMed

Malone, E D; Kannan, M S; Brown, D R

2000-10-01

To determine whether substance P (SP) functions as a neurotransmitter in equine jejunum. Samples of jejunum obtained from horses that did not have lesions in the gastrointestinal tract. Jejunal smooth muscle strips, oriented in the plane of the circular or longitudinal muscle, were suspended isometrically in muscle baths. Neurotransmitter release was induced by electrical field stimulation (EFS) delivered at 2 intensities (30 and 70 V) and various frequencies on muscle strips that were maintained at low tension or were under contraction. A neurokinin-1 receptor blocker (CP-96,345) was added to baths prior to EFS to interrupt SP neurotransmission. Additionally, direct effects of SP on muscle strips were evaluated, and SP-like immunoreactivity was localized in intestinal tissues, using indirect immunofluorescence testing. Substance P contracted circularly and longitudinally oriented muscle strips. Prior treatment with CP-96,345 altered muscle responses to SP and EFS, suggesting that SP was released from depolarized myenteric neurons. Depending on orientation of muscle strips and stimulation variables used, CP-96,345 increased or decreased the contractile response to EFS. Substance P-like immunoreactivity was detected in the myenteric plexus and circular muscle layers. Substance P appears to function as a neurotransmitter in equine jejunum. It apparently modulates smooth muscle contractility, depending on preexisting conditions. Effects of SP may be altered in some forms of intestinal dysfunction. Altering SP neurotransmission in the jejunum may provide a therapeutic option for motility disorders of horses that are unresponsive to adrenergic and cholinergic drugs.

Stellar-to-halo mass relation of cluster galaxies

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

Niemiec, Anna; Jullo, Eric; Limousin, Marceau

In the formation of galaxy groups and clusters, the dark matter haloes containing satellite galaxies are expected to be tidally stripped in gravitational interactions with the host. We use galaxy-galaxy weak lensing to measure the average mass of dark matter haloes of satellite galaxies as a function of projected distance to the centre of the host, since stripping is expected to be greater for satellites closer to the centre of the cluster. We further classify the satellites according to their stellar mass: assuming that the stellar component of the galaxy is less disrupted by tidal stripping, stellar mass can bemore » used as a proxy of the infall mass. We study the stellar to halo mass relation of satellites as a function of the cluster-centric distance to measure tidal stripping. We use the shear catalogues of the DES science veri cation archive, the CFHTLenS and the CFHT Stripe 82 surveys, and we select satellites from the redMaPPer catalogue of clusters. For galaxies located in the outskirts of clusters, we nd a stellar to halo mass relation in good agreement with the theoretical expectations from Moster, Naab & White (2013) for central galaxies. In the centre of the cluster, we nd that this relation is shifted to smaller halo mass for a given stellar mass. We interpret this nding as further evidence for tidal stripping of dark matter haloes in high density environments.« less

Stellar-to-halo mass relation of cluster galaxies

DOE PAGES

Niemiec, Anna; Jullo, Eric; Limousin, Marceau; ...

2017-07-04

In the formation of galaxy groups and clusters, the dark matter haloes containing satellite galaxies are expected to be tidally stripped in gravitational interactions with the host. We use galaxy-galaxy weak lensing to measure the average mass of dark matter haloes of satellite galaxies as a function of projected distance to the centre of the host, since stripping is expected to be greater for satellites closer to the centre of the cluster. We further classify the satellites according to their stellar mass: assuming that the stellar component of the galaxy is less disrupted by tidal stripping, stellar mass can bemore » used as a proxy of the infall mass. We study the stellar to halo mass relation of satellites as a function of the cluster-centric distance to measure tidal stripping. We use the shear catalogues of the DES science veri cation archive, the CFHTLenS and the CFHT Stripe 82 surveys, and we select satellites from the redMaPPer catalogue of clusters. For galaxies located in the outskirts of clusters, we nd a stellar to halo mass relation in good agreement with the theoretical expectations from Moster, Naab & White (2013) for central galaxies. In the centre of the cluster, we nd that this relation is shifted to smaller halo mass for a given stellar mass. We interpret this nding as further evidence for tidal stripping of dark matter haloes in high density environments.« less

Jellyfish: Observational Properties of Extreme Ram-Pressure Stripping Events in Massive Galaxy Clusters

NASA Astrophysics Data System (ADS)

Conor, McPartland; Ebeling, Harald; Roediger, Elke

2015-08-01

We investigate the physical origin and observational signatures of extreme ram-pressure stripping (RPS) in 63 massive galaxy clusters at z=0.3-0.7, based on data in the F606W passband obtained with the Advanced Camera for Surveys aboard the Hubble Space Telescope. Using a training set of a dozen ``jellyfish" galaxies identified earlier in the same imaging data, we define quantitative morphological criteria to select candidate galaxies which are similar to known cases of RPS. Considering a sample of 16 ``jellyfish" galaxies (10 of which we present for the first time), we visually derive estimates of the projected direction of motion based on dynamical features such as apparent compression shocks and debris trails. Our findings suggest that the observed events occur primarily at large distances from the cluster core and involve infall trajectories featuring high impact parameters. Simple models of cluster growth show that such trajectories are consistent with two scenarios: 1) galaxy infall along filaments; and 2) infall at high velocities (≥1000 km/s) characteristic of cluster mergers. The observed distribution of events is best described by timescales of ˜few Myr in agreement with recent numerical simulations of RPS. The broader areal coverage of the Hubble Frontier Fields should provide an even larger sample of RPS events to determine the relative contributions of infall and cluster mergers. Prompted by the discovery of several jellyfish galaxies whose brightness in the F606W passband rivals or exceeds that of the respective brightest cluster galaxy, we attempt to constrain the luminosity function of galaxies undergoing RPS. The observed significant excess at the bright end compared to the luminosity functions of blue cluster members strongly suggests enhanced star formation, thus challenging theoretical and numerical studies according to which RPS merely displaces existing star-forming regions. In-depth studies of individual objects will help test our conclusions and allow a quantitative comparison with predictions of theoretical and numerical models of ram-pressure stripping.

Adhesion of bacterial pathogens to soil colloidal particles: influences of cell type, natural organic matter, and solution chemistry.

PubMed

Zhao, Wenqiang; Walker, Sharon L; Huang, Qiaoyun; Cai, Peng

2014-04-15

Bacterial adhesion to granular soil particles is well studied; however, pathogen interactions with naturally occurring colloidal particles (<2 μm) in soil has not been investigated. This study was developed to identify the interaction mechanisms between model bacterial pathogens and soil colloids as a function of cell type, natural organic matter (NOM), and solution chemistry. Specifically, batch adhesion experiments were conducted using NOM-present, NOM-stripped soil colloids, Streptococcus suis SC05 and Escherichia coli WH09 over a wide range of solution pH (4.0-9.0) and ionic strength (IS, 1-100 mM KCl). Cell characterization techniques, Freundlich isotherm, and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory (sphere-sphere model) were utilized to quantitatively determine the interactions between cells and colloids. The adhesion coefficients (Kf) of S. suis SC05 to NOM-present and NOM-stripped soil colloids were significantly higher than E. coli WH09, respectively. Similarly, Kf values of S. suis SC05 and E. coli WH09 adhesion to NOM-stripped soil colloids were greater than those colloids with NOM-present, respectively, suggesting NOM inhibits bacterial adhesion. Cell adhesion to soil colloids declined with increasing pH and enhanced with rising IS (1-50 mM). Interaction energy calculations indicate these adhesion trends can be explained by DLVO-type forces, with S. suis SC05 and E. coli WH09 being weakly adhered in shallow secondary energy minima via polymer bridging and charge heterogeneity. S. suis SC05 adhesion decreased at higher IS 100 mM, which is attributed to the change of hydrophobic effect and steric repulsion resulted from the greater presence of extracellular polymeric substances (EPS) on S. suis SC05 surface as compared to E. coli WH09. Hence, pathogen adhesion to the colloidal material is determined by a combination of DLVO, charge heterogeneity, hydrophobic and polymer interactions as a function of solution chemistry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Simulation of upwind maneuvering of a sailing yacht

NASA Astrophysics Data System (ADS)

Harris, Daniel Hartrick

A time domain maneuvering simulation of an IACC class yacht suitable for the analysis of unsteady upwind sailing including tacking is presented. The simulation considers motions in six degrees of freedom. The hydrodynamic and aerodynamic loads are calculated primarily with unsteady potential theory supplemented by empirical viscous models. The hydrodynamic model includes the effects of incident waves. Control of the rudder is provided by a simple rate feedback autopilot which is augmented with open loop additions to mimic human steering. The hydrodynamic models are based on the superposition of force components. These components fall into two groups, those which the yacht will experience in calm water, and those due to incident waves. The calm water loads are further divided into zero Froude number, or "double body" maneuvering loads, hydrostatic loads, gravitational loads, free surface radiation loads, and viscous/residual loads. The maneuvering loads are calculated with an unsteady panel code which treats the instantaneous geometry of the yacht below the undisturbed free surface. The free surface radiation loads are calculated via convolution of impulse response functions derived from seakeeping strip theory. The viscous/residual loads are based upon empirical estimates. The aerodynamic model consists primarily of a database of steady state sail coefficients. These coefficients treat the individual contributions to the total sail force of a number of chordwise strips on both the main and jib. Dynamic effects are modeled by using the instantaneous incident wind velocity and direction as the independent variables for the sail load contribution of each strip. The sail coefficient database was calculated numerically with potential methods and simple empirical viscous corrections. Additional aerodynamic load calculations are made to determine the parasitic contributions of the rig and hull. Validation studies compare the steady sailing hydro and aerodynamic loads, seaway induced motions, added resistance in waves, and tacking performance with trials data and other sources. Reasonable agreement is found in all cases.

Assessing the Impact of Mechanical Damage on Full-Thickness Porcine and Human Skin Using an In Vitro Approach

PubMed Central

Builles, Nicolas; Frouin, Éric; Scott, Dan; Ramos, Jeanne; Marti-Mestres, Gilberte

2015-01-01

For most xenobiotics, the rates of percutaneous absorption are limited by diffusion through the horny layer of skin. However, percutaneous absorption of chemicals may seriously increase when the skin is damaged. The aim of this work was to develop an in vitro representative model of mechanically damaged skins. The epidermal barrier was examined following exposure to a razor, a rotating brush, and a microneedle system in comparison to tape-stripping which acted as a reference. Excised full-thickness skins were mounted on a diffusion chamber in order to evaluate the effect of injuries and to mimic physiological conditions. The transepidermal water loss (TEWL) was greatly increased when the barrier function was compromised. Measurements were made for all the damaged biopsies and observed histologically by microscopy. On human and porcine skins, the tape-stripping application (0 to 40 times) showed a proportional increase in TEWL which highlights the destruction of the stratum corneum. Similar results were obtained for all cosmetic instruments. This is reflected in our study by the nonsignificant difference of the mean TEWL scores between 30 strips and mechanical damage. For a specific appreciation, damaged skins were then selected to qualitatively evaluate the absorption of a chlorogenic acid solution using fluorescence microscopy. PMID:26247021

Near-membrane electric field calcium ion dehydration.

PubMed

Barger, James P; Dillon, Patrick F

2016-12-01

The dehydration of ion-water complexes prior to ion channel transit has focused on channel protein-mediated dissociation of water. Ion dehydration by the membrane electric field has not previously been considered. Near membrane electric fields have previously been shown to cause the disassociation of non-covalently bound small molecule-small molecule, small molecule-protein, and protein-protein complexes. It is well known that cosmotropic, structure making ions such as calcium and sodium significantly bind multiple water ions in solution. It is also known that these ions are often not hydrated as they pass through membrane ion channels. Using capillary electrophoresis, the range of electric fields needed to strip water molecules from calcium ions has been measured. Ion migration velocity is a linear function of the electric field. At low electric fields, the migration rate of calcium ion was shown to be linearly related to the applied electric field. Using a form of the Stoke's equation applicable to ion migration, the hydrated calcium radius was found to be 0.334nm, corresponding to a water hydration shell of 5.09 water molecules. At higher electric fields, the slope of the calcium migration velocity as a function of the electric field increased, which was modeled as a decrease in the radius of the migrating ion as the water was removed. Using a tanh function to model the transition of the ion from a hydrated to a stripped state, the transition had a midpoint at 446V/cm, and was 88% complete at 587V/cm with a correlation coefficient of 0.9996. The migration velocity of the stripped calcium ion was found to be a function of both the decrease in radius and an increase in the effective, electronic viscosity of the dipole medium through which the dehydrated ion moved. The size of the electric field needed to dehydrate calcium occurs 6-7nm from the cell membrane. Calcium ions within this distance from the membrane will be devoid of water molecules when they reach the calcium selective channel pore entrances, all known to be approximately 1-2nm from the membrane. No matter what the calcium pore structure, calcium ions reaching the channel entrance will be devoid of a water shell. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mathematical-Artificial Neural Network Hybrid Model to Predict Roll Force during Hot Rolling of Steel

NASA Astrophysics Data System (ADS)

Rath, S.; Sengupta, P. P.; Singh, A. P.; Marik, A. K.; Talukdar, P.

2013-07-01

Accurate prediction of roll force during hot strip rolling is essential for model based operation of hot strip mills. Traditionally, mathematical models based on theory of plastic deformation have been used for prediction of roll force. In the last decade, data driven models like artificial neural network have been tried for prediction of roll force. Pure mathematical models have accuracy limitations whereas data driven models have difficulty in convergence when applied to industrial conditions. Hybrid models by integrating the traditional mathematical formulations and data driven methods are being developed in different parts of world. This paper discusses the methodology of development of an innovative hybrid mathematical-artificial neural network model. In mathematical model, the most important factor influencing accuracy is flow stress of steel. Coefficients of standard flow stress equation, calculated by parameter estimation technique, have been used in the model. The hybrid model has been trained and validated with input and output data collected from finishing stands of Hot Strip Mill, Bokaro Steel Plant, India. It has been found that the model accuracy has been improved with use of hybrid model, over the traditional mathematical model.

Stress intensity factors and COD in an orthotropic strip

NASA Technical Reports Server (NTRS)

Kaya, A. C.; Erdogan, F.

1980-01-01

The elasticity problem for an orthotropic strip or a beam with an internal or an edge crack under general loading conditions is considered. The numerical results are given for four basic loading conditions, namely, uniform tension, pure bending, three point bending, and concentrated surface shear loading. For the strip with an edge crack additional results regarding the crack opening displacements are obtained by using the plastic strip model. A critical quantity which is tabulated is the maximum compressive stress in the plane of the crack. It is shown that this stress may easily exceed the yield limit in compression and hence may severely limit the range of application of the plasticity results.

High power cladding light stripper using segmented corrosion method: theoretical and experimental studies.

PubMed

Yin, Lu; Yan, Mingjian; Han, Zhigang; Wang, Hailin; Shen, Hua; Zhu, Rihong

2017-04-17

We present the segmented corrosion method that uses hydrofluoric acid to etch the fiber of a fiber laser for removing high-power cladding light to improve stripping uniformity and power handling capability. For theoretical guidelines, we propose a simulation model of etched-fiber stripping to evaluate the relationship between the etched-fiber parameters and cladding light attenuation and to analyze the stripping uniformity achieved with segmented corrosion. A two-segment etched fiber is fabricated with cladding light attenuation of 19.8 dB and power handling capability up to 670 W. We find that the cladding light is stripped uniformly and the temperature distribution is uniform without the formation of hot spots.

Design and development of equipment for laser wire stripping

NASA Technical Reports Server (NTRS)

Iceland, W. F.

1977-01-01

Three laser wire strippers have been built for the stripping of Kapton-insulated wire, the baseline wire of the space shuttle orbiter. The strippers are: (1) a bench-model stripper powered with a cw CO2 10.6-micron laser, (2) a hand-held stripper powered with a cw 1.06-micron Nd-YAG laser with an output of 5-7 watts, and (3) a hand-held stripper with a five-inch-long CO2 laser inside the stripping head.

The different growth pathways of Brightest Cluster Galaxies and the Intra-Cluster Light

NASA Astrophysics Data System (ADS)

Contini, E.; Yi, S. K.; Kang, X.

2018-06-01

We study the growth pathways of Brightest Central Galaxies (BCGs) and Intra-Cluster Light (ICL) by means of a semi-analytic model. We assume that the ICL forms by stellar stripping of satellite galaxies and violent processes during mergers, and implement two independent models: (1) one considers both mergers and stellar stripping (named STANDARD model), and one considers only mergers (named MERGERS model). We find that BCGs and ICL form, grow and overall evolve at different times and with different timescales, but they show a clear co-evolution after redshift z ˜ 0.7 - 0.8. Around 90% of the ICL from stellar stripping is built-up in the innermost 150 Kpc from the halo centre and the dominant contribution comes from disk-like galaxies (B/T<0.4) through a large number of small/intermediate stripping events (Mstrip/Msat < 0.3). The fractions of stellar mass in BCGs and in ICL over the total stellar mass within the virial radius of the halo evolve differently with time. At high redshift, the BCG accounts for the bulk of the mass, but its contribution gradually decreases with time and stays constant after z ˜ 0.4 - 0.5. The ICL, instead, grows very fast and its contribution keeps increasing down to the present time. The STANDARD and the MERGERS models make very similar predictions in most of the cases, but predict different amounts of ICL associated to other galaxies within the virial radius of the group/cluster other than the BCG, at z = 0. We then suggest that this quantity is a valid observable that can shed light on the relative importance of mergers and stellar stripping for the formation of the ICL.

360-degrees profilometry using strip-light projection coupled to Fourier phase-demodulation.

PubMed

Servin, Manuel; Padilla, Moises; Garnica, Guillermo

2016-01-11

360 degrees (360°) digitalization of three dimensional (3D) solids using a projected light-strip is a well-established technique in academic and commercial profilometers. These profilometers project a light-strip over the digitizing solid while the solid is rotated a full revolution or 360-degrees. Then, a computer program typically extracts the centroid of this light-strip, and by triangulation one obtains the shape of the solid. Here instead of using intensity-based light-strip centroid estimation, we propose to use Fourier phase-demodulation for 360° solid digitalization. The advantage of Fourier demodulation over strip-centroid estimation is that the accuracy of phase-demodulation linearly-increases with the fringe density, while in strip-light the centroid-estimation errors are independent. Here we proposed first to construct a carrier-frequency fringe-pattern by closely adding the individual light-strip images recorded while the solid is being rotated. Next, this high-density fringe-pattern is phase-demodulated using the standard Fourier technique. To test the feasibility of this Fourier demodulation approach, we have digitized two solids with increasing topographic complexity: a Rubik's cube and a plastic model of a human-skull. According to our results, phase demodulation based on the Fourier technique is less noisy than triangulation based on centroid light-strip estimation. Moreover, Fourier demodulation also provides the amplitude of the analytic signal which is a valuable information for the visualization of surface details.

Direct Quantification of Cd2+ in the Presence of Cu2+ by a Combination of Anodic Stripping Voltammetry Using a Bi-Film-Modified Glassy Carbon Electrode and an Artificial Neural Network.

PubMed

Zhao, Guo; Wang, Hui; Liu, Gang

2017-07-03

Abstract : In this study, a novel method based on a Bi/glassy carbon electrode (Bi/GCE) for quantitatively and directly detecting Cd 2+ in the presence of Cu 2+ without further electrode modifications by combining square-wave anodic stripping voltammetry (SWASV) and a back-propagation artificial neural network (BP-ANN) has been proposed. The influence of the Cu 2+ concentration on the stripping response to Cd 2+ was studied. In addition, the effect of the ferrocyanide concentration on the SWASV detection of Cd 2+ in the presence of Cu 2+ was investigated. A BP-ANN with two inputs and one output was used to establish the nonlinear relationship between the concentration of Cd 2+ and the stripping peak currents of Cu 2+ and Cd 2+ . The factors affecting the SWASV detection of Cd 2+ and the key parameters of the BP-ANN were optimized. Moreover, the direct calibration model (i.e., adding 0.1 mM ferrocyanide before detection), the BP-ANN model and other prediction models were compared to verify the prediction performance of these models in terms of their mean absolute errors (MAEs), root mean square errors (RMSEs) and correlation coefficients. The BP-ANN model exhibited higher prediction accuracy than the direct calibration model and the other prediction models. Finally, the proposed method was used to detect Cd 2+ in soil samples with satisfactory results.

Diffraction Analysis of Antennas With Mesh Surfaces

NASA Technical Reports Server (NTRS)

Rahmat-Samii, Yahya

1987-01-01

Strip-aperture model replaces wire-grid model. Far-field radiation pattern of antenna with mesh reflector calculated more accurately with new strip-aperture model than with wire-grid model of reflector surface. More adaptable than wire-grid model to variety of practical configurations and decidedly superior for reflectors in which mesh-cell width exceeds mesh thickness. Satisfies reciprocity theorem. Applied where mesh cells are no larger than tenth of wavelength. Small cell size permits use of simplifying approximation that reflector-surface current induced by electromagnetic field is present even in apertures. Approximation useful in calculating far field.

Mechanistic modeling & effectiveness of buffer strips for pesticide regulatory frameworks

USDA-ARS?s Scientific Manuscript database

Vegetative Filter Strips (VFS) have been used as an effective conservation practice in agricultural areas for controlling and mitigate the effect of sediment, nutrients and pesticides loads into water bodies. In addition to the agricultural sector, another important use of VFS for controlling plague...

Bladder smooth muscle organ culture preparation maintains the contractile phenotype

PubMed Central

Wang, Tanchun; Kendig, Derek M.; Chang, Shaohua; Trappanese, Danielle M.; Chacko, Samuel

2012-01-01

Smooth muscle cells, when subjected to culture, modulate from a contractile to a secretory phenotype. This has hampered the use of cell culture for molecular techniques to study the regulation of smooth muscle biology. The goal of this study was to develop a new organ culture model of bladder smooth muscle (BSM) that would maintain the contractile phenotype and aid in the study of BSM biology. Our results showed that strips of BSM subjected to up to 9 days of organ culture maintained their contractile phenotype, including the ability to achieve near-control levels of force with a temporal profile similar to that of noncultured tissues. The technical aspects of our organ culture preparation that were responsible, in part, for the maintenance of the contractile phenotype were a slight longitudinal stretch during culture and subjection of the strips to daily contraction-relaxation. The tissues contained viable cells throughout the cross section of the strips. There was an increase in extracellular collagenous matrix, resulting in a leftward shift in the passive length-tension relationship. There were no significant changes in the content of smooth muscle-specific α-actin, calponin, h-caldesmon, total myosin heavy chain, protein kinase G, Rho kinase-I, or the ratio of SM1 to SM2 myosin isoforms. Moreover the organ cultured tissues maintained functional voltage-gated calcium channels and large-conductance calcium-activated potassium channels. Therefore, we propose that this novel BSM organ culture model maintains the contractile phenotype and will be a valuable tool for the use in cellular/molecular biology studies of bladder myocytes. PMID:22896042

The Preferential Tidal Stripping of Dark Matter versus Stars in Galaxies

NASA Astrophysics Data System (ADS)

Smith, Rory; Choi, Hoseung; Lee, Jaehyun; Rhee, Jinsu; Sanchez-Janssen, Ruben; Yi, Sukyoung K.

2016-12-01

Using high-resolution hydrodynamical cosmological simulations, we conduct a comprehensive study of how tidal stripping removes dark matter and stars from galaxies. We find that dark matter is always stripped far more significantly than the stars—galaxies that lose ˜80% of their dark matter, typically lose only 10% of their stars. This is because the dark matter halo is initially much more extended than the stars. As such, we find that the stellar-to-halo size-ratio (measured using r eff/r vir) is a key parameter controlling the relative amounts of dark matter and stellar stripping. We use simple fitting formulae to measure the relation between the fraction of bound dark matter and the fraction of bound stars. We measure a negligible dependence on cluster mass or galaxy mass. Therefore, these formulae have general applicability in cosmological simulations, and are ideal to improve stellar stripping recipes in semi-analytical models, and/or to estimate the impact that tidal stripping would have on galaxies when only their halo mass evolution is known.

Economic comparison of methods of wound closure: wound closure strips vs. sutures and wound adhesives.

PubMed

Zempsky, William T; Zehrer, Cindy L; Lyle, Christopher T; Hedbloom, Edwin C

2005-09-01

Our objective was to review and assess the treatment of low-tension wounds and evaluate the cost-effectiveness of wound closure methods. We used a health economic model to estimate cost/closure of adhesive wound closure strips, tissue adhesives and sutures. The model incorporated cost-driving variables: application time, costs and the likelihood and costs of dehiscence and infection. The model was populated with variable estimates derived from the literature. Cost estimates and cosmetic results were compared. Parameter values were estimated using national healthcare and labour statistics. Sensitivity analyses were used to verify the results. Our analysis suggests that adhesive wound closure strips had the lowest average cost per laceration ($7.54), the lowest cost per infected laceration ($53.40) and the lowest cost per laceration with dehiscence ($25.40). The costs for sutures were $24.11, $69.91 and $41.91, respectively; the costs for tissue adhesives were $28.77, $74.68 and $46.68, respectively. The cosmetic outcome for all three treatments was equivalent. We conclude adhesive wound closure strips were both a cost-saving and a cost-effective alternative to sutures and tissue adhesives in the closure of low-tension lacerations.

Mosaicing of airborne LiDAR bathymetry strips based on Monte Carlo matching

NASA Astrophysics Data System (ADS)

Yang, Fanlin; Su, Dianpeng; Zhang, Kai; Ma, Yue; Wang, Mingwei; Yang, Anxiu

2017-09-01

This study proposes a new methodology for mosaicing airborne light detection and ranging (LiDAR) bathymetry (ALB) data based on Monte Carlo matching. Various errors occur in ALB data due to imperfect system integration and other interference factors. To account for these errors, a Monte Carlo matching algorithm based on a nonlinear least-squares adjustment model is proposed. First, the raw data of strip overlap areas were filtered according to their relative drift of depths. Second, a Monte Carlo model and nonlinear least-squares adjustment model were combined to obtain seven transformation parameters. Then, the multibeam bathymetric data were used to correct the initial strip during strip mosaicing. Finally, to evaluate the proposed method, the experimental results were compared with the results of the Iterative Closest Points (ICP) and three-dimensional Normal Distributions Transform (3D-NDT) algorithms. The results demonstrate that the algorithm proposed in this study is more robust and effective. When the quality of the raw data is poor, the Monte Carlo matching algorithm can still achieve centimeter-level accuracy for overlapping areas, which meets the accuracy of bathymetry required by IHO Standards for Hydrographic Surveys Special Publication No.44.

The looped adhesive strip: An example of coplanar delamination interaction

NASA Technical Reports Server (NTRS)

Bottega, W. J.

1990-01-01

The phenomenon of peeling and debonding of thin layers is a subject of interest to those concerned with adhesives, thin films, and layered materials. In recent years much attention has been focused on such problems as a result of increased interest and application of advanced composites and thin film coatings. A related problem which is of interest for its own sake but also represents a simple example of a tangled adhesive strip and of coplanar delamination interaction, is the problem of a looped adhesive strip. This is the subject of the present study. Researchers consider here the problem of an elastic strip which possesses an adherend on (at least) one of its surfaces. If the strip is deformed so that two portions of such a surface are brought into contact, a position of the strip becomes bonded and a loop is formed. Researchers are interested in determining the equilibrium configuration of such a strip and investigating the behavior of the strip when its edges are pulled apart. The problem is approached as a moving interior boundary problem in the calculus of variations with the strip modeled as an inextensible elastica and the bond strength characterized by its surface energy. A Griffith type energy criterion is employed for debonding, and solutions corresponding to the problem of interest obtained. The solution obtained will be seen to predict the interesting phenomenon of bond point propagation, as well as the more standard peeling type behavior. Numerical results demonstrating the phenomena of interest are presented as well and will be seen to reveal both stable and unstable propagation of the boundaries of the bonded portion of the strip, depending upon the loading conditions.

State-space modeling of population sizes and trends in Nihoa Finch and Millerbird

USGS Publications Warehouse

Gorresen, P. Marcos; Brinck, Kevin W.; Camp, Richard J.; Farmer, Chris; Plentovich, Sheldon M.; Banko, Paul C.

2016-01-01

Both of the 2 passerines endemic to Nihoa Island, Hawai‘i, USA—the Nihoa Millerbird (Acrocephalus familiaris kingi) and Nihoa Finch (Telespiza ultima)—are listed as endangered by federal and state agencies. Their abundances have been estimated by irregularly implemented fixed-width strip-transect sampling from 1967 to 2012, from which area-based extrapolation of the raw counts produced highly variable abundance estimates for both species. To evaluate an alternative survey method and improve abundance estimates, we conducted variable-distance point-transect sampling between 2010 and 2014. We compared our results to those obtained from strip-transect samples. In addition, we applied state-space models to derive improved estimates of population size and trends from the legacy time series of strip-transect counts. Both species were fairly evenly distributed across Nihoa and occurred in all or nearly all available habitat. Population trends for Nihoa Millerbird were inconclusive because of high within-year variance. Trends for Nihoa Finch were positive, particularly since the early 1990s. Distance-based analysis of point-transect counts produced mean estimates of abundance similar to those from strip-transects but was generally more precise. However, both survey methods produced biologically unrealistic variability between years. State-space modeling of the long-term time series of abundances obtained from strip-transect counts effectively reduced uncertainty in both within- and between-year estimates of population size, and allowed short-term changes in abundance trajectories to be smoothed into a long-term trend.

A preliminary analysis of the data from experiment 77-13 and final report on glass fining experiments in zero gravity

NASA Technical Reports Server (NTRS)

Wilcox, W. R.; Subramanian, R. S.; Meyyappan, M.; Smith, H. D.; Mattox, D. M.; Partlow, D. P.

1981-01-01

Thermal fining, thermal migration of bubbles under reduced gravity conditions, and data to verify current theoretical models of bubble location and temperatures as a function of time are discussed. A sample, sodium borate glass, was tested during 5 to 6 minutes of zero gravity during rocket flight. The test cell contained a heater strip; thermocouples were in the sample. At present quantitative data are insufficient to confirm results of theoretical calculations.

The Vertex on a Strip

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

Kashani-Poor, A.

2004-11-03

We demonstrate that for a broad class of local Calabi-Yau geometries built around a string of IP{sup 1}s--those whose toric diagrams are given by triangulations of a strip--we can derive simple rules, based on the topological vertex, for obtaining expressions for the topological string partition function in which the sums over Young tableaux have been performed. By allowing non-trivial tableaux on the external legs of the corresponding web diagrams, these strips can be used as building blocks for more general geometries. As applications of our result, we study the behavior of topological string amplitudes under flops, as well as checkmore » Nekrasov's conjecture in its most general form.« less

An extraction process to recover vanadium from low-grade vanadium-bearing titanomagnetite.

PubMed

Chen, Desheng; Zhao, Hongxin; Hu, Guoping; Qi, Tao; Yu, Hongdong; Zhang, Guozhi; Wang, Lina; Wang, Weijing

2015-08-30

An extraction process to recover vanadium from low-grade vanadium-bearing titanomagnetite was developed. In this study, a mixed solvent system of di(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP) diluted with kerosene was used for the selective extraction of vanadium from a hydrochloric acid leaching solution that contained low vanadium concentration with high concentrations of iron and impurities of Ca, Mg, and Al. In the extraction process, the initial solution pH and the phase ratio had considerable functions in the extraction of vanadium from the hydrochloric acid leaching solution. Under optimal extraction conditions (i.e., 30-40°C for 10min, 1:3 phase ratio (O/A), 20% D2EHPA concentration (v/v), and 0-0.8 initial solution pH), 99.4% vanadium and only 4.2% iron were extracted by the three-stage counter-current extraction process. In the stripping process with H2SO4 as the stripping agent and under optimal stripping conditions (i.e., 20% H2SO4 concentration, 5:1 phase ratio (O/A), 20min stripping time, and 40°C stripping temperature), 99.6% vanadium and only 5.4% iron were stripped by the three-stage counter-current stripping process. The stripping solution contained 40.16g/LV2O5,0.691g/L Fe, 0.007g/L TiO2, 0.006g/L SiO2 and 0.247g/L CaO. A V2O5 product with a purity of 99.12% V2O5 and only 0.026% Fe was obtained after the oxidation, precipitation, and calcination processes. The total vanadium recovered from the hydrochloric acid leaching solution was 85.5%. Copyright © 2015 Elsevier B.V. All rights reserved.

Individual Template-Stripped Conductive Gold Pyramids for Tip-Enhanced Dielectrophoresis

PubMed Central

2015-01-01

Gradient fields of optical, magnetic, or electrical origin are widely used for the manipulation of micro- and nanoscale objects. Among various device geometries to generate gradient forces, sharp metallic tips are one of the most effective. Surface roughness and asperities present on traditionally produced tips reduce trapping efficiencies and limit plasmonic applications. Template-stripped, noble metal surfaces and structures have sub-nm roughness and can overcome these limits. We have developed a process using a mix of conductive and dielectric epoxies to mount template-stripped gold pyramids on tungsten wires that can be integrated with a movable stage. When coupled with a transparent indium tin oxide (ITO) electrode, the conductive pyramidal tip functions as a movable three-dimensional dielectrophoretic trap which can be used to manipulate submicrometer-scale particles. We experimentally demonstrate the electrically conductive functionality of the pyramidal tip by dielectrophoretic manipulation of fluorescent beads and concentration of single-walled carbon nanotubes, detected with fluorescent microscopy and Raman spectroscopy. PMID:25541619

Spatial optimization of watershed management practices for nitrogen load reduction using a modeling-optimization framework.

PubMed

Yang, Guoxiang; Best, Elly P H

2015-09-15

Best management practices (BMPs) can be used effectively to reduce nutrient loads transported from non-point sources to receiving water bodies. However, methodologies of BMP selection and placement in a cost-effective way are needed to assist watershed management planners and stakeholders. We developed a novel modeling-optimization framework that can be used to find cost-effective solutions of BMP placement to attain nutrient load reduction targets. This was accomplished by integrating a GIS-based BMP siting method, a WQM-TMDL-N modeling approach to estimate total nitrogen (TN) loading, and a multi-objective optimization algorithm. Wetland restoration and buffer strip implementation were the two BMP categories used to explore the performance of this framework, both differing greatly in complexity of spatial analysis for site identification. Minimizing TN load and BMP cost were the two objective functions for the optimization process. The performance of this framework was demonstrated in the Tippecanoe River watershed, Indiana, USA. Optimized scenario-based load reduction indicated that the wetland subset selected by the minimum scenario had the greatest N removal efficiency. Buffer strips were more effective for load removal than wetlands. The optimized solutions provided a range of trade-offs between the two objective functions for both BMPs. This framework can be expanded conveniently to a regional scale because the NHDPlus catchment serves as its spatial computational unit. The present study demonstrated the potential of this framework to find cost-effective solutions to meet a water quality target, such as a 20% TN load reduction, under different conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Frequency dispersions of human skin dielectrics.

PubMed Central

Poon, C S; Choy, T T

1981-01-01

The electrical properties of many biological materials are known to exhibit frequency dispersions. In the human skin, the impedance measured at various frequencies closely describes a circular locus of the Cole-Cole type in the complex impedance plane. In this report, the formative mechanisms responsible for the anomalous circular-arc behavior of skin impedance were investigated, using data from impedance measurements taken after successive strippings of the skin. The data were analyzed with respect to changes in the parameters of the equivalent Cole-Cole model after each stripping. For an exponential resistivity profile (Tregear, 1966, Physical Functions of Skin; Yamamoto and Yamamoto, 1976, Med. Biol. Eng., 14:151--158), the profile of the dielectric constant was shown to be uniform across the epidermis. Based on these results, a structural model has been formulated in terms of the relaxation theory of Maxwell and Wagner for inhomogeneous dielectric materials. The impedance locus obtained from the model approximates a circular are with phase constant alpha = 0.82, which compares favorably with experimental data. At higher frequencies a constant-phase, frequency-dependent component having the same phase constant alpha is also demonstrated. It is suggested that an approximately rectangular distribution of the relaxation time over the epidermal dielectric sheath is adequate to account for the anomalous frequency characteristics of human skin impedance. PMID:7213928

Development of a Rat Model to Investigate Contributions of Anatomic and Physiologic Determinants of in Vivo Skin Permeation

DTIC Science & Technology

1991-08-30

physiologic states. Physiologic perturbations were performed to test the sensitivity of the model system to detect effects of minoxidil -mediated... Minoxidil , leukotriene D̂ , tape stripping of stratum corneum, and topical ether-ethanol experiments produced statistically significant increases (52 to... Minoxidil 68 B. Phenylephrine 69 C. Leukotriene D̂ 69 D. Ether-Ethanol 70 E. Tape stripping 76 8. Data analysis 77 Vlll RESULTS 80 1

Discrete mathematical model of wave diffraction on pre-fractal impedance strips. TM mode case

NASA Astrophysics Data System (ADS)

Nesvit, K. V.

2013-10-01

In this paper a transverse magnetic (TM) wave diffraction problem on pre-fractal impedance strips is considered. The overall aim of this work is to develop a discrete mathematical model of the boundary integral equations (IEs) with the help of special quadrature formulas with the nodes in the zeros of Chebyshev polynomials and to perform a numerical experiments with the help of an efficient discrete singularities method (DSM).

Intensity of regionally applied tastes in relation to administration method: an investigation based on the "taste strips" test.

PubMed

Manzi, Brian; Hummel, Thomas

2014-02-01

To compare various methods to apply regional taste stimuli to the tongue. "Taste strips" are a clinical tool to determine gustatory function. How a patient perceives the chemical environment in the mouth is a result of many factors such as taste bud distribution and interactions between the cranial nerves. To date, there have been few studies describing the different approaches to administer taste strips to maximize taste identification accuracy and intensity. This is a normative value acquisition pilot and single-center study. The investigation involved 30 participants reporting a normal sense of smell and taste (18 women, 12 men, mean age 33 years). The taste test was based on spoon-shaped filter paper strips impregnated with four taste qualities (sweet, sour, salty, and bitter) at concentrations shown to be easily detectable by young healthy subjects. The strips were administered in three methods (held stationary on the tip of the tongue, applied across the tongue, held in the mouth), resulting in a total of 12 trials per participant. Subjects identified the taste from a list of four descriptors, (sweet, sour, salty, bitter) and ranked the intensity on a scale from 0 to 10. Statistical analyses were performed on the accuracy of taste identification and rated intensities. The participants perceived in order of most to least intense: salt, sour, bitter, sweet. Of the four tastes, sour consistently was least accurately identified. Presenting the taste strip inside the closed mouth of the participants produced the least accurate taste identification, whereas moving the taste strip across the tongue led to a significant increase in intensity for the sweet taste. In this study of 30 subjects at the second concentration, optimized accuracy and intensity of taste identification was observed through administration of taste strips laterally across the anterior third of the extended tongue. Further studies are required on more subjects and the additional concentrations prior to determining the ideal taste strip application method.

Scattering of electromagnetic plane wave from a perfect electric conducting strip placed at interface of topological insulator-chiral medium

NASA Astrophysics Data System (ADS)

Shoukat, Sobia; Naqvi, Qaisar A.

2016-12-01

In this manuscript, scattering from a perfect electric conducting strip located at planar interface of topological insulator (TI)-chiral medium is investigated using the Kobayashi Potential method. Longitudinal components of electric and magnetic vector potential in terms of unknown weighting function are considered. Use of related set of boundary conditions yields two algebraic equations and four dual integral equations (DIEs). Integrand of two DIEs are expanded in terms of the characteristic functions with expansion coefficients which must satisfy, simultaneously, the discontinuous property of the Weber-Schafheitlin integrals, required edge and boundary conditions. The resulting expressions are then combined with algebraic equations to express the weighting function in terms of expansion coefficients, these expansion coefficients are then substituted in remaining DIEs. The projection is applied using the Jacobi polynomials. This treatment yields matrix equation for expansion coefficients which is solved numerically. These unknown expansion coefficients are used to find the scattered field. The far zone scattering width is investigated with respect to different parameters of the geometry, i.e, chirality of chiral medium, angle of incidence, size of the strip. Significant effects of different parameters including TI parameter on the scattering width are noted.

Riparian buffer strips as a multifunctional management tool in agricultural landscapes: introduction.

PubMed

Stutter, Marc I; Chardon, Wim J; Kronvang, Brian

2012-01-01

Catchment riparian areas are considered key zones to target mitigation measures aimed at interrupting the movement of diffuse substances from agricultural land to surface waters. Hence, unfertilized buffer strips have become a widely studied and implemented "edge of field" mitigation measure assumed to provide an effective physical barrier against nitrogen (N), phosphorus (P), and sediment transfer. To ease the legislative process, these buffers are often narrow mandatory strips along streams and rivers, across different riparian soil water conditions, between bordering land uses of differing pollution burdens, and without prescribed buffer management. It would be easy to criticize such regulation for not providing the opportunity for riparian ecosystems to maximize their provision for a wider range of ecosystem goods and services. The scientific basis for judging the best course of action in designing and placing buffers to enhance their multifunctionality has slowly increased over the last five years. This collection of papers aims to add to this body of knowledge by giving examples of studies related to riparian buffer management and assessment throughout Europe. This introductory paper summarizes discussion sessions and 13 selected papers from a workshop held in Ballater, UK, highlighting research on riparian buffers brought together under the EU COST Action 869 knowledge exchange program. The themes addressed are (i) evidence of catchment- to national-scale effectiveness, (ii) ecological functioning linking terrestrial and aquatic habitats, (iii) modeling tools for assessment of effectiveness and costs, and (iv) process understanding enabling management and manipulation to enhance pollutant retention in buffers. The combined understanding led us to consider four principle key questions to challenge buffer strip research and policy. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Degradation kinetics of gamma-oryzanol in antioxidant-stripped rice bran oil during thermal oxidation.

PubMed

Khuwijitjaru, Pramote; Yuenyong, Thippawan; Pongsawatmanit, Rungnaphar; Adachi, Shuji

2009-01-01

Gamma-oryzanol, a group of phytosterol ferulates found in rice bran, possesses antioxidative activity and other bioactivities. The kinetics of thermal degradation of gamma-oryzanol in stripped rice bran oil (SRBO) were investigated under heating at 132, 160, 192 and 222 degrees C for 480, 140, 60 and 50 h, respectively. Losses of the overall gamma-oryzanol and its components (cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate and beta-sitosteryl ferulate) could be expressed by the first-order kinetics model. The rate constant of thermal degradation of gamma-oryzanol increased with increasing heating temperatures. The temperature dependence of the obtained rate constants was found to obey the Arrhenius equation. Campesteryl ferulate showed slightly more thermally resistant than other components at temperature lower than 160 degrees C. However, the change in the absorbance from 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay as a function of heating time exhibited the same pattern for the SRBO with and without gamma-oryzanol for all studied heating temperatures.

[Resistance of the functional systems of the smooth muscle cells of isolated myometrium to long-term incubation in Ringer-Locke solution at 4 degrees C].

PubMed

Peshikov, V L; Tsirkin, V I; Burmistrova, T D; Bordunovskaia, V P

1977-09-01

Contractile effects of adrenaline, acethylcholine and hyperpotassium solution on the isolated myometrium strips (non-pregnent rats, and women; pregnant rabbits, cats, and women) are studied. The amplitudes of these contractile effects were seen decreasing if the strips were previously immersed in the Ringer-Lokk solution at 4 degrees C 5--9 days prior to observation.

Compressive strength of delaminated aerospace composites.

PubMed

Butler, Richard; Rhead, Andrew T; Liu, Wenli; Kontis, Nikolaos

2012-04-28

An efficient analytical model is described which predicts the value of compressive strain below which buckle-driven propagation of delaminations in aerospace composites will not occur. An extension of this efficient strip model which accounts for propagation transverse to the direction of applied compression is derived. In order to provide validation for the strip model a number of laminates were artificially delaminated producing a range of thin anisotropic sub-laminates made up of 0°, ±45° and 90° plies that displayed varied buckling and delamination propagation phenomena. These laminates were subsequently subject to experimental compression testing and nonlinear finite element analysis (FEA) using cohesive elements. Comparison of strip model results with those from experiments indicates that the model can conservatively predict the strain at which propagation occurs to within 10 per cent of experimental values provided (i) the thin-film assumption made in the modelling methodology holds and (ii) full elastic coupling effects do not play a significant role in the post-buckling of the sub-laminate. With such provision, the model was more accurate and produced fewer non-conservative results than FEA. The accuracy and efficiency of the model make it well suited to application in optimum ply-stacking algorithms to maximize laminate strength.

Microgap flat panel display

DOEpatents

Wuest, C.R.

1998-12-08

A microgap flat panel display is disclosed which includes a thin gas-filled display tube that utilizes switched X-Y ``pixel`` strips to trigger electron avalanches and activate a phosphor at a given location on a display screen. The panel utilizes the principal of electron multiplication in a gas subjected to a high electric field to provide sufficient electron current to activate standard luminescent phosphors located on an anode. The X-Y conductive strips of a few micron widths may for example, be deposited on opposite sides of a thin insulating substrate, or on one side of the adjacent substrates and function as a cathode. The X-Y strips are separated from the anode by a gap filled with a suitable gas. Electrical bias is selectively switched onto X and Y strips to activate a ``pixel`` in the region where these strips overlap. A small amount of a long-lived radioisotope is used to initiate an electron avalanche in the overlap region when bias is applied. The avalanche travels through the gas filled gap and activates a luminescent phosphor of a selected color. The bias is adjusted to give a proportional electron multiplication to control brightness for given pixel. 6 figs.

[Penile augmentation and elongation using autologous dermal-fat strip grafting].

PubMed

Yang, Zhe; Li, Yang-qun; Tang, Yong; Chen, Wen; Li, Qiang; Zhou, Chuan-de; Zhao, Mu-xin; Hu, Chun-mei

2012-05-01

To investigate the effect of autologous dermal-fat strip grafting in penile augmentation and elongation. From May 2004 to December 2010, 24 patients underwent penile enhancement with free dermal-fat strip grafting. Through suprapubic incision, the superior suspensory ligament and part deep suspensory ligament are cutted off to lengthen the penis. The resulted dead space is filled with the autologous dermal-fat strip (6.0-9.5 cm in length, 1.2-1.5 cm in width and 0.6-0.8 cm in depth) to enhance the penis. Primary healing was achieved in 23 cases. Incisional fat liquefaction happened in one case which healed after dressing change. The penile appearance was satisfactory both at rest or erection. The penile length and circumference increased by 2.5-4.8 cm (average, 3.2 cm) and 1.8-3.0 cm (average, 2.4 cm), respectively. 18 patients were followed up for 3 months to 5 years. All the patients were satisfactory on the cosmetic and functional results. No complication happened. It is safe and effective for penile augmention and elongation with autologous dermal-fat strip grafting and disconnection of penile suspensory ligament.

Contractile properties of the pig bladder mucosa in response to neurokinin A: a role for myofibroblasts?

PubMed Central

Sadananda, P; Chess-Williams, R; Burcher, E

2008-01-01

Background and purpose: The bladder urothelium is now known to have active properties. Our aim was to investigate the contractile properties of the urinary mucosa in response to the tachykinin neurokinin A (NKA) and carbachol. Experimental approach: Discrete concentration–response curves for carbachol and NKA were obtained in matched strips of porcine detrusor, mucosa and intact bladder, suspended in organ baths. The effects of inhibitors and tachykinin receptor antagonists were studied on NKA-mediated contractions in mucosal strips. Intact sections of bladder and experimental strips were processed for histology and immunohistochemistry. Key results: All types of strips contracted to both carbachol and NKA. Mucosal responses to NKA (pD2 7.2) were higher than those in intact strips and were inhibited by the NK2 receptor antagonist SR48968 (pKB 9.85) but not the NK1 receptor antagonist SR140333, tetrodotoxin or indomethacin. Immunostaining for smooth muscle actin and vimentin occurred under the urothelium and on blood vessels. Desmin immunostaining and histological studies showed only sparse smooth muscle to be present in the mucosal strips. Removal of smooth muscle remnants from mucosal strips did not alter the responses to NKA. Conclusions and implications: This study has shown both functional and histological evidence for contractile properties of the mucosa, distinct from the detrusor. Mucosal contractions to NKA appear to be directly mediated via NK2 receptors. The main cell type mediating mucosal contractions is suggested to be suburothelial myofibroblasts. Mucosal contractions may be important in vivo for matching the luminal surface area to bladder volume. PMID:18264120

Electrical properties of human skin as aging biomarkers.

PubMed

Simić-Krstić, Jovana B; Kalauzi, Aleksandar J; Ribar, Srdjan N; Matija, Lidija R; Misevic, Gradimir N

2014-09-01

A non-invasive bioimpedance spectroscopy (BIS) and Cole-Cole impedance model parameters (R0, R∞, τ and α) were used to analyze electrical properties of intact and stripped human skin for both gender subjects divided into younger and older age groups. R0, R∞ and τ significantly increased while α significantly decreased with age in stripped skin for both genders (p<0.031). Using pooled data with respect to age, gender and skin stripping, R0, R∞ and τ values were shown to increase with age (p<0.0034), R0, τ and α were different between genders (p<0.024) and R0, R∞ and τ decreased with skin stripping (p<0.000008). All of four Cole-Cole parameters were age dependent with specific differences observed for genders and intact and stripped skin layers. Therefore, Cole-Cole parameters, obtained by non-invasive BIS measurements, are a new type of age dependent biomarkers. Copyright © 2014 Elsevier Inc. All rights reserved.

Upconversion fluorescent strip sensor for rapid determination of Vibrio anguillarum

NASA Astrophysics Data System (ADS)

Zhao, Peng; Wu, Yuanyuan; Zhu, Yihua; Yang, Xiaoling; Jiang, Xin; Xiao, Jingfan; Zhang, Yuanxing; Li, Chunzhong

2014-03-01

Here, we report a simple and ultrasensitive upconversion fluorescent strip sensor based on NaYF4:Yb,Er nanoparticles (NPs) and the lateral flow immunochromatographic assay (LFIA). Carboxyl-modified β-NaYF4:Yb,Er NPs were successfully synthesized by a facile one-pot solvothermal approach, upon further coupling with monoclonal antibody, the resultant UCNPs-antibody conjugates probes were used in LFIA and served as signal vehicles for the fluorescent reporters. V. anguillarum was used as a model analyte to demonstrate the use of this strip sensor. The limit of the detection for the fluorescent strip was determined as 102 CFU mL-1, which is 100 times lower than those displayed by enzyme-linked immunosorbent assays, while the time needed for the detection was only 15 min. Furthermore, no cross-reaction with other eight pathogens was found, indicating the good specificity of the strip. This developed LFIA would offer the potential as a useful tool for the quantification of pathogens analysis in the future.

LABORATORY-SCALE ANALYSIS OF AQUIFER REMEDIATION BY IN-WELL VAPOR STRIPPING 2. MODELING RESULTS. (R825689C061)

EPA Science Inventory

Abstract

The removal of volatile organic compounds (VOCs) from groundwater through in-well vapor stripping has been demonstrated by Gonen and Gvirtzman (1997, J. Contam. Hydrol., 00: 000-000) at the laboratory scale. The present study compares experimental breakthrough...

Recovery of Volatile Fatty Acids from Fermented Wastewater by Adsorption

PubMed Central

2017-01-01

Separation of volatile fatty acids (VFAs) from fermented wastewater is challenging, due to low VFA concentrations in mineral-rich streams. As a result, separation capacity and selectivity with traditional solvents and adsorbents are both compromised. In this study, using a complex artificial model solution mimicking real fermented wastewaters, it is shown that a simple and robust adsorption-based separation technique can retain a remarkable capacity and selectivity for VFAs. Four types of polystyrene-divinylbenzene-based resins (primary, secondary, and tertiary amine-functionalized, and nonfunctionalized) were examined as the adsorbents. The presence of chloride, sulfate, and phosphate salts resulted in coadsorption of their acidic forms HCl, H2SO4, and H3PO4 on amine-functionalized adsorbents, and severely reduced the VFA capacity. With the nonfunctionalized adsorbent, almost no mineral acid coadsorption was observed. This together with a high total VFA capacity of up to 76 g/kg in equilibrium with the model solution containing a total VFA concentration of 1 wt % resulted in a very high selectivity for the VFAs. Nitrogen-stripping with various temperature profiles was applied to regenerate the adsorbent, and study the potential for fractionation of the VFAs during regeneration. Butyric acid (HBu) was obtained in mole fractions of up to 0.8 using a stepwise increase in the stripping temperature from 25 °C via 120 to 200 °C. During four successive adsorption–regeneration cycles, no reduction in the adsorption capacity was observed. PMID:28989827

Assessment of skin barrier function and biochemical changes of ex vivo human skin in response to physical and chemical barrier disruption.

PubMed

Döge, Nadine; Avetisyan, Araks; Hadam, Sabrina; Pfannes, Eva Katharina Barbosa; Rancan, Fiorenza; Blume-Peytavi, Ulrike; Vogt, Annika

2017-07-01

Topical dermatotherapy is intended to be used on diseased skin. Novel drug delivery systems even address differences between intact and diseased skin underlining the need for pre-clinical assessment of different states of barrier disruption. Herein, we studied how short-term incubation in culture media compared to incubation in humidified chambers affects human skin barrier function and viability. On both models we assessed different types and intensities of physical and chemical barrier disruption methods with regard to structural integrity, biophysical parameters and cytokine levels. Tissue degeneration and proliferative activity limited the use of tissue cultures to 48h. Viability is better preserved in cultured tissue. Tape-stripping (50×TS) and 4h sodium lauryl sulfate (SLS) pre-treatment were identified as highly reproducible and effective procedures for barrier disruption. Transepidermal water loss (TEWL) values reproducibly increased with the intensity of disruption while sebum content and skin surface pH were of limited value. Interleukin (IL)-6/8 and various chemokines and proteases were increased in tape-stripped skin which was more pronounced in SLS-treated skin tissue extracts. Thus, albeit limited to 48h, cultured full-thickness skin maintained several barrier characteristics and responded to different intensities of barrier disruption. Potentially, these models can be used to assess pre-clinically the efficacy and penetration of anti-inflammatory compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimizing the recovery of copper from electroplating rinse bath solution by hollow fiber membrane.

PubMed

Oskay, Kürşad Oğuz; Kul, Mehmet

2015-01-01

This study aimed to recover and remove copper from industrial model wastewater solution by non-dispersive solvent extraction (NDSX). Two mathematical models were developed to simulate the performance of an integrated extraction-stripping process, based on the use of hollow fiber contactors using the response surface method. The models allow one to predict the time dependent efficiencies of the two phases involved in individual extraction or stripping processes. The optimal recovery efficiency parameters were determined as 227 g/L of H2SO4 concentration, 1.22 feed/strip ratio, 450 mL/min flow rate (115.9 cm/min. flow velocity) and 15 volume % LIX 84-I concentration in 270 min by central composite design (CCD). At these optimum conditions, the experimental value of recovery efficiency was 95.88%, which was in close agreement with the 97.75% efficiency value predicted by the model. At the end of the process, almost all the copper in the model wastewater solution was removed and recovered as CuSO4.5H2O salt, which can be reused in the copper electroplating industry.

Point-based and model-based geolocation analysis of airborne laser scanning data

NASA Astrophysics Data System (ADS)

Sefercik, Umut Gunes; Buyuksalih, Gurcan; Jacobsen, Karsten; Alkan, Mehmet

2017-01-01

Airborne laser scanning (ALS) is one of the most effective remote sensing technologies providing precise three-dimensional (3-D) dense point clouds. A large-size ALS digital surface model (DSM) covering the whole Istanbul province was analyzed by point-based and model-based comprehensive statistical approaches. Point-based analysis was performed using checkpoints on flat areas. Model-based approaches were implemented in two steps as strip to strip comparing overlapping ALS DSMs individually in three subareas and comparing the merged ALS DSMs with terrestrial laser scanning (TLS) DSMs in four other subareas. In the model-based approach, the standard deviation of height and normalized median absolute deviation were used as the accuracy indicators combined with the dependency of terrain inclination. The results demonstrate that terrain roughness has a strong impact on the vertical accuracy of ALS DSMs. From the relative horizontal shifts determined and partially improved by merging the overlapping strips and comparison of the ALS, and the TLS, data were found not to be negligible. The analysis of ALS DSM in relation to TLS DSM allowed us to determine the characteristics of the DSM in detail.

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

Sotiriadis, Charalampos; Hajdu, Steven David; Degrauwe, Sophie

With the increased use of implanted venous access devices (IVADs) for continuous long-term venous access, several techniques such as percutaneous endovascular fibrin sheath removal, have been described, to maintain catheter function. Most standard techniques do not capture the stripped fibrin sheath, which is subsequently released in the pulmonary circulation and may lead to symptomatic pulmonary embolism. The presented case describes an endovascular technique which includes stripping, capture, and removal of fibrin sheath using a novel filter device. A 64-year-old woman presented with IVAD dysfunction. Stripping was performed using a co-axial snare to the filter to capture the fibrin sheath. Themore » captured fragment was subsequently removed for visual and pathological verification. No immediate complication was observed and the patient was discharged the day of the procedure.« less

Advances in x-ray framing cameras at the National Ignition Facility to improve quantitative precision in x-ray imaging

DOE PAGES

Benedetti, L. R.; Holder, J. P.; Perkins, M.; ...

2016-02-26

We describe an experimental method to measure the gate profile of an x-ray framing camera and to determine several important functional parameters: relative gain (between strips), relative gain droop (within each strip), gate propagation velocity, gate width, and actual inter-strip timing. Several of these parameters cannot be measured accurately by any other technique. This method is then used to document cross talk-induced gain variations and artifacts created by radiation that arrives before the framing camera is actively amplifying x-rays. Electromagnetic cross talk can cause relative gains to vary significantly as inter-strip timing is varied. This imposes a stringent requirement formore » gain calibration. If radiation arrives before a framing camera is triggered, it can cause an artifact that manifests as a high-intensity, spatially varying background signal. Furthermore, we have developed a device that can be added to the framing camera head to prevent these artifacts.« less

Advances in x-ray framing cameras at the National Ignition Facility to improve quantitative precision in x-ray imaging.

PubMed

Benedetti, L R; Holder, J P; Perkins, M; Brown, C G; Anderson, C S; Allen, F V; Petre, R B; Hargrove, D; Glenn, S M; Simanovskaia, N; Bradley, D K; Bell, P

2016-02-01

We describe an experimental method to measure the gate profile of an x-ray framing camera and to determine several important functional parameters: relative gain (between strips), relative gain droop (within each strip), gate propagation velocity, gate width, and actual inter-strip timing. Several of these parameters cannot be measured accurately by any other technique. This method is then used to document cross talk-induced gain variations and artifacts created by radiation that arrives before the framing camera is actively amplifying x-rays. Electromagnetic cross talk can cause relative gains to vary significantly as inter-strip timing is varied. This imposes a stringent requirement for gain calibration. If radiation arrives before a framing camera is triggered, it can cause an artifact that manifests as a high-intensity, spatially varying background signal. We have developed a device that can be added to the framing camera head to prevent these artifacts.

Formalin produces depolarizations in human airway smooth muscle in vitro.

PubMed

Richards, Ira S; DeHate, Robin B

2006-03-01

Respiratory irritants may result in airway smooth muscle (ASM) depolarization and bronchoconstriction. We examined the effect of formalin on membrane potentials in human ASM in two types of in vitro preparations: strip preparations, which contain functional sensory and motor nerve endings and cultured cells, which lack these nerve endings due to the tissue dissociation process. Depolarizations occurred in atropine-treated strip preparations in response to formalin exposures, but not in similarly-treated cultured cells, suggesting a role for non-cholinergic mediators in formalin-induced depolarization. It is suggested that formalin may act as an irritant to produce bronchoconstriction that is mediated by the release of endogenous substance P (SP) from peripheral sensory nerve endings. This is supported by our observation that exogenous SP produced depolarizations of a magnitude similar to those produced by formalin in both strip preparations and cultured cells. In addition, capsaicin, which releases endogenous SP from nerve endings, produced depolarizations of a magnitude similar to formalin in strip preparations, but was without effect in cultured cells.

Effects of unconventional breakup modes on incomplete fusion of weakly bound nuclei

NASA Astrophysics Data System (ADS)

Diaz-Torres, Alexis; Quraishi, Daanish

2018-02-01

The incomplete fusion dynamics of 6Li+209Bi collisions at energies above the Coulomb barrier is investigated. The classical dynamical model implemented in the platypus code is used to understand and quantify the impact of both 6Li resonance states and transfer-triggered breakup modes (involving short-lived projectile-like nuclei such as 8Be and 5Li) on the formation of incomplete fusion products. Model calculations explain the experimental incomplete-fusion excitation function fairly well, indicating that (i) delayed direct breakup of 6Li reduces the incomplete fusion cross sections and (ii) the neutron-stripping channel practically determines those cross sections.

Self-Monitoring of Blood Glucose Levels: Evaluating the Impact of a Policy of Quantity Limits on Test-Strip Use and Costs.

PubMed

Gomes, Tara; Martins, Diana; Tadrous, Mina; Paterson, J Michael; Shah, Baiju R; Juurlink, David N; Singh, Samantha; Mamdani, Muhammad M

2016-10-01

To evaluate the impact of new quantity limits for blood glucose test strips (BGTS) in August 2013 on utilization patterns and costs in the elderly population of Ontario, Canada. We conducted a population-based, cross-sectional time series analysis of all individuals 65 years of age and older who received publically funded BGTSs between August 1, 2010, and July 31, 2015, in Ontario, Canada. The number of BGTSs dispensed and the associated costs were measured for 4 diabetes therapy subgroups-insulin, hypoglycemia-inducing oral agents, non-hypoglycemia-inducing oral agents, and no drug therapy-each month during the study period. We used interventional autoregressive integrated moving average (ARIMA) models to assess the impact of Ontario's policy change on test strip use and costs. In the course of the study period, 657,338,177 test strips were dispensed to elderly patients in Ontario, at a total cost of CAN$482.3 million. Introduction of quantity limits was associated with significant reductions in the number of monthly strips dispensed and the associated costs (p<0.0001). In the year following the policy's implementation, test strip use decreased by 22.2% compared with the prior year (from 145,232,024 test strips to 113,007,795 test strips, a net decrease of 32,224,229 strips), resulting in a 22.5% reduction in costs (from $106.5 million to $82.6 million, a net cost reduction of approximately $24 million). The introduction of quantity limits, aligned with guidance from the Canadian Diabetes Association, led to immediate significant reductions in BGTS dispensing and costs. More research is needed to assess the impact of this policy on patient outcomes. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Evaluation of Aution Max AX-4030 and 9UB Uriflet, 10PA Aution Sticks urine dipsticks in the automated urine test strip analysis.

PubMed

Rota, Cristina; Biondi, Marco; Trenti, Tommaso

2011-09-26

Aution Max AX-4030, a test strip analyzer recently introduced to the market, represents an upgrade of the Aution Max AX-4280 widely employed for urinalysis. This new instrument model can allocate two different test strips at the same time. In the present study the two instruments have been compared together with the usage of Uriflet 9UB and the recently produced Aution Sticks 10PA urine strips, the latter presenting an additional test area for the measurement of urinary creatinine. Imprecision and correlation between instruments and strips have been evaluated for chemical-physical parameters. Accuracy was evaluated for protein, glucose and creatinine by comparing the semi-quantitative results to those obtained by quantitative methods. The well-known interference effect of high ascorbic acid levels on urine glucose test strip determination was evaluated, ascorbic acid influence was also evaluated on protein and creatinine determination. The two instruments have demonstrated comparable performances: precision and correlation between instruments and strips, evaluated for chemical-physical parameters, were always good. Furthermore, accuracy was always very good: results of protein and glucose semi-quantitative measurements resulted to be highly correlated with those obtained by quantitative methods. Moreover, the semi-quantitative measurements of creatinine, employing Aution Sticks 10PA urine strips, were highly comparable with quantitative results. 10PA urine strips are eligible for urine creatinine determination with the possibility of correcting urinalysis results for urinary creatinine concentration, whenever necessary and calculating the protein creatinine ratio. Further studies should be carried out to evaluate effectiveness and appropriateness of the usage of creatinine semi-quantitative analysis.

Frictional interactions in forming processes: New studies with transparent sapphire strip-drawing dies

NASA Astrophysics Data System (ADS)

Rao, R. S.; Lu, C. Y.; Wright, P. K.; Devenpeck, M. L.; Richmond, O.; Appleby, E. J.

1982-05-01

This research is concerned with the frictional interactions at the toolwork interfaces in the machining and strip-drawing processes. A novel feature is that transparent sapphire (single crystal Al2O3) is being used as the tool and die material. This allows the tribological features of the interface to be directly observed and recorded on movie-film. These qualitative studies provide information on the role of lubricants. In addition, techniques are being developed to quantify the velocity gradient along the interface. For example, in the drawing work it has been found that tracer markings (e.g. dye-spots), applied to the undrawn strip, remain intact during drawing and can be tracked along the sapphire/strip interface. Such data will be used as input to a finite-element, elasto-plastic-workhardening model of the deformation process. The latter can compute strip deformation characteristics, drawing forces and local coefficients of friction at the interface. Introductory results will be presented in this paper, obtained from drawing tin-plated mild steel with sapphire and cemented carbide dies. Drawing loads and die-separating forces will be presented and movie-films of the action of tracer markings at the interface shown. In order to demonstrate how this data can be used in an analysis of a large strain deformation process with friction, initial results from running the FIPDEF elasto-plastic code will be discussed. From a commercial viewpoint research on strip-drawing is of special interest to the can-making industry. From a physical viewpoint stripdrawing is of particular interest because it is a symmetrical, plane strain deformation and, in comparison with other metal processing operations, it is more readily modeled. However, until now the elasto-plastic codes that have been developed to predictively model drawing have had limitations: the most notable being that of quantifying the friction conditions at the die-work interface. Hence the specification of the latter is the ultimate goal of this research program.

Prediction of Thrombus Growth: Effect of Stenosis and Reynolds Number.

PubMed

Hosseinzadegan, Hamid; Tafti, Danesh K

2017-06-01

Shear stresses play a major role in platelet-substrate interactions and thrombus formation and growth in blood flow, where under both pathological and physiological conditions platelet adhesion and accumulation occur. In this study, a shear-dependent continuum model for platelet activation, adhesion and aggregation is presented. The model was first verified under three different shear conditions and at two heparin levels. Three-dimensional simulations were then carried out to evaluate the performance of the model for severely damaged (stripped) aortas with mild and severe stenosis degrees in laminar flow regime. For these cases, linear shear-dependent functions were developed for platelet-surface and platelet-platelet adhesion rates. It was confirmed that the platelet adhesion rate is not only a function of Reynolds number (or wall shear rate) but also the stenosis severity of the vessel. General correlations for adhesion rates of platelets as functions of stenosis and Reynolds number were obtained based on these cases. Finally using the new platelet adhesion rates, the model was applied to different experimental systems and shown to agree well with measured platelet deposition.

Optimizing the Distribution of Tie Points for the Bundle Adjustment of HRSC Image Mosaics

NASA Astrophysics Data System (ADS)

Bostelmann, J.; Breitkopf, U.; Heipke, C.

2017-07-01

For a systematic mapping of the Martian surface, the Mars Express orbiter is equipped with a multi-line scanner: Since the beginning of 2004 the High Resolution Stereo Camera (HRSC) regularly acquires long image strips. By now more than 4,000 strips covering nearly the whole planet are available. Due to the nine channels, each with different viewing direction, and partly with different optical filters, each strip provides 3D and color information and allows the generation of digital terrain models (DTMs) and orthophotos. To map larger regions, neighboring HRSC strips can be combined to build DTM and orthophoto mosaics. The global mapping scheme Mars Chart 30 is used to define the extent of these mosaics. In order to avoid unreasonably large data volumes, each MC-30 tile is divided into two parts, combining about 90 strips each. To ensure a seamless fit of these strips, several radiometric and geometric corrections are applied in the photogrammetric process. A simultaneous bundle adjustment of all strips as a block is carried out to estimate their precise exterior orientation. Because size, position, resolution and image quality of the strips in these blocks are heterogeneous, also the quality and distribution of the tie points vary. In absence of ground control points, heights of a global terrain model are used as reference information, and for this task a regular distribution of these tie points is preferable. Besides, their total number should be limited because of computational reasons. In this paper, we present an algorithm, which optimizes the distribution of tie points under these constraints. A large number of tie points used as input is reduced without affecting the geometric stability of the block by preserving connections between strips. This stability is achieved by using a regular grid in object space and discarding, for each grid cell, points which are redundant for the block adjustment. The set of tie points, filtered by the algorithm, shows a more homogenous distribution and is considerably smaller. Used for the block adjustment, it yields results of equal quality, with significantly shorter computation time. In this work, we present experiments with MC-30 half-tile blocks, which confirm our idea for reaching a stable and faster bundle adjustment. The described method is used for the systematic processing of HRSC data.

A new extension to the Taste Strips test.

PubMed

Wolf, Axel; Illini, Oliver; Uy, Daniel; Renner, Bertold; Mueller, Christian A

2016-03-01

Assessment of gustatory function in human subjects using the 'taste strips' test is an easy and validated procedure. The aim of this study was to extend this test in order to detect subjects with superior gustatory sensitivity. The investigation included 134 subjects (29.5±12.6 years, range 18-84 years) with normal gustatory function. Four concentrations of sweet, sour, salty, and bitter were augmented with additional low concentrations (sweet: 25/12.5 mg/ml sucrose; sour: 27/15 mg/ml citric acid; salty: 6.4/2.6 mg/ml sodium chloride, bitter: 0.15/0.06 mg/ml quinine hydrochloride), resulting in a maximum extended taste score (ETS) of 24. The mean ETS was 14.5 ± 3.2. Specifically, it was 4.5 ± 1.2 for sweet, 2.8 ± 1.0 for sour, 4.0 ± 1.3 for salty, and 3.2 ± 1.2 for bitter. In contrast to the original version of the taste strips test, no ceiling effect was observed. Cluster analysis separated three groups of subjects by ETS, whereas test scores derived from the original four concentrations were insufficient to discriminate the subgroup with higher gustatory sensitivity. The extended taste strips test seems to be a useful tool for the detection of patients with low gustatory thresholds for sweet, sour, salty, or bitter taste.

Development of Lateral Flow Immunochromatographic Strips for Micropollutants Screening Using Colorants of Aptamer Functionalized Nanogold Particles Part I: Methodology and Optimization.

PubMed

Zhao, Shuai; Zhang, Shan; Wang, Sai; Liu, Jiahui; Dong, Yiyang

2018-05-03

A methodology of lateral flow immunochromatographic strip based on aptamer was developed for on-site detectionof the small molecule micropollutants. In the present study, we try for the first time to investigate the feasibility of developing a strip assay for the analysis of micropollutants as methodological prototypes by combining the high selectivity and affinity of aptamers with the unique optical properties of nanogolds. This quantitative method was based on the competition for the aptamer between targets and DNA probes. Crucial parameters that might influence the sensitivity, such as the size of nanogolds, amount of aptamer, type and pH of streptavidin, type of nitrocellulose (NC) membrane, blocking procedure, and reading time, were systematically investigated to obtain the optimum assay performance. With the optimized conditions [nanogolds 25 nm, 50 μM aptamer, pH 8 of GSA (a type of streptavidin named "SA Gold," which is a sulfhydrylization streptavidin), Millipore HFC 135 NC membrane, 1% bovine serum albumin as the blocking agent and added in the running buffer and sample pad soakage agents, and 20 min reading time] the aptamer-based lateral flow assay will show a low visual limit of detection and scanning reader LOD. The strip for on-site screening using colorants of aptamer functionalized nanogold particles did not require any complicated equipment and was a potential portable tool for rapid identification of micropollutants.

Circuit Models for Inductive Strips in Fin-Line

DTIC Science & Technology

1989-12-01

9875 SE523 35.9875 Ma6 12S.9075 12.0 .7975 120.1500 . 6034 30.1500 . 6034 30.1500 .7975 120.1SO0 13 9.~~~- - M II I I’ IT I II f j a I ; a ~ ~ ~ ~ ~ I I...42.553.1 .8174 132.55371 34 Table 12. Touchstone data file containing the computed scattering coefficients of anl inductive strip of length T= 200 mnils...6283 45.0422 .628H 45.0422 .7780 13S.0422 42 Table 20. Touchstone data file containing the computed scattering coefficients of anl inductive strip of

Experiences gained from implementing mandatory buffer strips in Denmark: how can we enhance their ecosystem services?

NASA Astrophysics Data System (ADS)

Kronvang, Brian; Hoffmann, Carl Christian; Baattrup-Pedersen, Annette; Hille, Sandra; Rubæk, Gitte; Heckrath, Goswin; Gertz, Flemming; Jensen, Henning; Feuerback, Peter; Strand, John; Stutter, Marc

2015-04-01

The Danish Parliament adopted in June 2012 a Buffer Strip Act that required 10 m mandatory buffer strips (BSs) to be established along all watercourses and lakes with a surface area greater than 100 m2 from 1st September 2012. The main reasons for deploying BSs was to reduce nitrate-N leaching and phosphorus (P) loss via surface runoff from adjoining fields from the approximately 50,000 ha of BSs as no farming activities were allowed in the BS concerning use of fertilizer, spreading of manure, spraying with pesticides, etc. Reductions in nutrient losses to watercourses are needed for minimizing the eutrophication effects in lakes and coastal waters. Buffer strips are among the most well studied and frequently adapted mitigation measure for reducing sediment and P losses to surface waters via surface runoff. It has, however, been questioned if BSs can also reduce N losses. The international literature gives an overwhelming support to their functioning for reduction in sediment and especially particulate P losses. However, their functioning for dissolved P and nitrogen is more questionable when comparing studies from the international literature. In Denmark, many farmers were against the introduction of BSs as a general mitigation measure for several reasons. The most used argument in the public debate was that BSs in general are not very efficient for reducing N and P losses to surface waters which was originally the argument behind the BS Act from the Ministries of Environment and Food and Agriculture. A desk study had been made prior to the adaptation of the law that showed 10 m BSs to be able to reduce the N loading with 40-50 kg N ha-1 of BS and 0.04-0.4 kg P ha-1 BS. The total reduction from the BSs established in Denmark in 2012 would then amount to 2,000-2,500 tonnes N and 2-20 tonnes P. The intense public debate in Denmark made the Parliament to adopt a new BS law in June 2014 to be implemented in August 2014 that reduced the total areas with mandatory BSs along watercourses from ca. 50,000 ha to ca. 25,000 ha and at the same time they reduced the width of the mandatory BSs from 10 m to 9 m. The aim of this presentation is to share the experience gained in Denmark on establishing mandatory BSs. Furthermore, we will show some preliminary results from two newly initiated research projects (BUFFERTECH and BALTICSEA2020) that studies how to enhance the ecosystem services provided by buffer strips. We will show how intelligently to guide managers when establishing BSs along watercourses at catchment scale utilizing a combined P-index model for soil erosion and a statistical model for P retention in BSs as well as results obtained from new 'Engineered' or 'Constructed' BSs that delays tile drainage flow from field to streams thereby increasing nutrient retention. Acknowledgement The work is supported by the Strategic Research Foundation/Innovation Fund Denmark project 'BUFFERTECH - Optimization of Ecosystem Services Provided by Buffer Strips Using Novel Technological Methods' (Grant No. 1305-00017B) and the BalticSea2020 project 'Integrerade skyddszoner (IBZ)'.

A carbon dioxide stripping model for mammalian cell culture in manufacturing scale bioreactors.

PubMed

Xing, Zizhuo; Lewis, Amanda M; Borys, Michael C; Li, Zheng Jian

2017-06-01

Control of carbon dioxide within the optimum range is important in mammalian bioprocesses at the manufacturing scale in order to ensure robust cell growth, high protein yields, and consistent quality attributes. The majority of bioprocess development work is done in laboratory bioreactors, in which carbon dioxide levels are more easily controlled. Some challenges in carbon dioxide control can present themselves when cell culture processes are scaled up, because carbon dioxide accumulation is a common feature due to longer gas-residence time of mammalian cell culture in large scale bioreactors. A carbon dioxide stripping model can be used to better understand and optimize parameters that are critical to cell culture processes at the manufacturing scale. The prevailing carbon dioxide stripping models in literature depend on mass transfer coefficients and were applicable to cell culture processes with low cell density or at stationary/cell death phase. However, it was reported that gas bubbles are saturated with carbon dioxide before leaving the culture, which makes carbon dioxide stripping no longer depend on a mass transfer coefficient in the new generation cell culture processes characterized by longer exponential growth phase, higher peak viable cell densities, and higher specific production rate. Here, we present a new carbon dioxide stripping model for manufacturing scale bioreactors, which is independent of carbon dioxide mass transfer coefficient, but takes into account the gas-residence time and gas CO 2 saturation time. The model was verified by CHO cell culture processes with different peak viable cell densities (7 to 12 × 10 6  cells mL -1 ) for two products in 5,000-L and 25,000-L bioreactors. The model was also applied to a next generation cell culture process to optimize cell culture conditions and reduce carbon dioxide levels at manufacturing scale. The model provides a useful tool to understand and better control cell culture carbon dioxide profiles for process development, scale up, and characterization. Biotechnol. Bioeng. 2017;114: 1184-1194. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

BUDHIES II: a phase-space view of H I gas stripping and star formation quenching in cluster galaxies

NASA Astrophysics Data System (ADS)

Jaffé, Yara L.; Smith, Rory; Candlish, Graeme N.; Poggianti, Bianca M.; Sheen, Yun-Kyeong; Verheijen, Marc A. W.

2015-04-01

We investigate the effect of ram-pressure from the intracluster medium on the stripping of H I gas in galaxies in a massive, relaxed, X-ray bright, galaxy cluster at z = 0.2 from the Blind Ultra Deep H I Environmental Survey (BUDHIES). We use cosmological simulations, and velocity versus position phase-space diagrams to infer the orbital histories of the cluster galaxies. In particular, we embed a simple analytical description of ram-pressure stripping in the simulations to identify the regions in phase-space where galaxies are more likely to have been sufficiently stripped of their H I gas to fall below the detection limit of our survey. We find a striking agreement between the model predictions and the observed location of H I-detected and non-detected blue (late-type) galaxies in phase-space, strongly implying that ram-pressure plays a key role in the gas removal from galaxies, and that this can happen during their first infall into the cluster. However, we also find a significant number of gas-poor, red (early-type) galaxies in the infall region of the cluster that cannot easily be explained with our model of ram-pressure stripping alone. We discuss different possible additional mechanisms that could be at play, including the pre-processing of galaxies in their previous environment. Our results are strengthened by the distribution of galaxy colours (optical and UV) in phase-space, that suggests that after a (gas-rich) field galaxy falls into the cluster, it will lose its gas via ram-pressure stripping, and as it settles into the cluster, its star formation will decay until it is completely quenched. Finally, this work demonstrates the utility of phase-space diagrams to analyse the physical processes driving the evolution of cluster galaxies, in particular H I gas stripping.

Water body and riparian buffer strip characteristics in a vineyard area to support aquatic pesticide exposure assessment.

PubMed

Ohliger, Renja; Schulz, Ralf

2010-10-15

The implementation of a geodata-based probabilistic pesticide exposure assessment for surface waters in Germany offers the opportunity to base the exposure estimation on more differentiated assumptions including detailed landscape characteristics. Since these characteristics can only be estimated using field surveys, water body width and depth, hydrology, riparian buffer strip width, ground vegetation cover, existence of concentrated flow paths, and riparian vegetation were characterised at 104 water body segments in the vineyard region Palatinate (south-west Germany). Water body segments classified as permanent (n=43) had median values of water body width and depth of 0.9m and 0.06m, respectively, and the determined median width:depth ratio was 15. Thus, the deterministic water body model (width=1m; depth=0.3m) assumed in regulatory exposure assessment seems unsuitable for small water bodies in the study area. Only 25% of investigated buffer strips had a dense vegetation cover (>70%) and allow a laminar sheet flow as required to include them as an effective pesticide runoff reduction landscape characteristic. At 77 buffer strips, bordering field paths and erosion rills leading into the water body were present, concentrating pesticide runoff and consequently decreasing buffer strip efficiency. The vegetation type shrubbery (height>1.5m) was present at 57 (29%) investigated riparian buffer strips. According to their median optical vegetation density of 75%, shrubberies may provide a spray drift reduction of 72±29%. Implementing detailed knowledge in an overall assessment revealed that exposure via drift might be 2.4 and via runoff up to 1.6 fold higher than assumed by the deterministic approach. Furthermore, considering vegetated buffer strips only by their width leads to an underestimation of exposure by a factor of as much as four. Our data highlight that the deterministic model assumptions neither represent worst-case nor median values and therefore cannot simply be adopted in a probabilistic approach. Copyright © 2010 Elsevier B.V. All rights reserved.

Deployment hinge using wraparound strips

NASA Technical Reports Server (NTRS)

Blanc, Eric

1992-01-01

Aerospatiale developed a new appendage deployment concept called AMEDE (French acronym for improvement of deployment mechanisms) with a view toward increased simplicity and functional reliability. This new concept, applicable to the deployment of any type of spaceborne appendage (in particular to solar arrays), enables deployment without synchronization or speed regulation devices. On the other hand, it requires the use of hinges with low driving or resistive torques. The AMEDE concept is compared with the conventional deployment concept. The conceptual and functional principles for the ADELE hinge are presented, as well as the hinges' main characteristics. The development status of both the AMEDE concept and the ADELE (French acronym for deployment hinge using wraparound strips) hinge are addressed.

Modelling of RR Lyrae instability strips

NASA Astrophysics Data System (ADS)

Szabo, Robert; Csubry, Zoltan

2001-02-01

Recent studies indicates that the slope of the empirical blue edge of the RR Lyrae fundamental mode instability strip is irreconcilable with the theoretical blue edges. Nonlinear hydrodynamical pulsational code involving turbulent convection was used to follow fundamental/first overtone mode selection mechanism. This method combined with the results of horizontal branch evolutionary computations was applied to rethink the problem.

Anthropogenic desertification by high-albedo pollution Observations and modeling

NASA Technical Reports Server (NTRS)

Otterman, J.; Rosenberg, N. W.; Rosenberg, E.

1974-01-01

ERTS-1 MSS albedo data of Western Negev, Sinai and the Gaza strip are presented. A sharp contrast in albedo exists across the Negev-Sinai and Negev-Gaza strip borders. Anthropogenic desertification has occurred on the Arab side due to overgrazing and Bedouin agriculture, whereas natural vegetation grows much more abundantly on the Israeli side.

Selective removal of 2,4-dichlorophenoxyacetic acid from water by molecularly-imprinted amino-functionalized silica gel sorbent.

PubMed

Han, Deman; Jia, Wenping; Liang, Huading

2010-01-01

A molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-dichlorophenoxyacetic acid (2,4-D) was prepared by a surface imprinting technique in combination with a sol-gel process. The 2,4-D-imprinted amino-functionalized silica sorbent was characterized by FT-IR, nitrogen adsorption and static adsorption experiments. The selectivity of the sorbent was investigated by a batch competitive binding experiment using an aqueous 2,4-D and 2,4-dichlorophenol (2,4-DCP) mixture or using an aqueous 2,4-D and 2,4-dichlorophenylacetic acid (DPAC) mixture. The largest selectivity coefficient for 2,4-D in the presence of 2,4-DCP was found to be over 18, the largest relative selectivity coefficient between 2,4-D and 2,4-DCP over 9. The static uptake capacity and selectivity coefficient of the 2,4-D-imprinted functionalized sorbent are higher than those of the non-imprinted sorbent. The imprinted functionalized silica gel sorbent offered a fast kinetics for the extraction/stripping of 2,4-D, 73% of binding capacity (200 mg/L 2,4-D onto 20 mg of imprinted sorbent) was obtained within 5 min and the adsorbed 2,4-D can be easily stripped by the mixture solution of ethanol and 6 mol/L HCl (V:V = 1:1). In a test of five extraction/stripping cycles, the adsorption capacity of the sorbent was all above 93% of that of the fresh sorbent. Experimental result showed the potential of molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-D.

Differential Sensitivities of Pulmonary and Coronary Arteries to Hemoglobin-Based Oxygen Carriers and Nitrovasodilators: Study in a Bovine Ex Vivo Model of Vascular Strips

DTIC Science & Technology

2010-01-01

dependent manner, with a relatively high average IC50 of8.5 J.lM (Table 1 ). For bovine pulmonary artery, the JC50 for sodium nitrite was more than 1... dependent on nitrovasodilator concentration, suggesting SNP and sodium nitrite -induced autocatalytic conversion of oxyhemoglobin to methemoglobin at...Gladwin, M.T., Kim-Shapiro, D.R., 2008. The functional nitrite reductase activity of the heme -globins. Blood 112, 2636-2647. Hart, j.L, Ledvina, M.A

Standardization of an in vitro Model for Evaluating the Bioavailability of Topically Applied Compounds on Damaged Skin: Application to Sunscreen Analysis.

PubMed

Jacques-Jamin, Carine; Jeanjean-Miquel, Corinne; Domergue, Anaïs; Bessou-Touya, Sandrine; Duplan, Hélène

2017-01-01

Information is lacking on the dermal penetration of topically applied formulations on in vitro skin models, under conditions where the stratum corneum (SC) is damaged. Therefore, we have developed a standardized in vitro barrier-disrupted skin model using tape stripping. Different tape stripping conditions were evaluated using histology, transepidermal water loss, infrared densitometry, and caffeine absorption. The effects of tape stripping were comparable using pig and human skin. Optimized conditions were used to test the effect of SC damage and UV irradiation on the absorption of an UV filter combination present in a sunscreen. The bioavailability of the filters was extremely low regardless of the extent of skin damage, suggesting bioavailability would not be increased if the consumer applied the sunscreen to sun-damaged skin. This standardized in vitro methodology using pig or human skin for damaged skin will add valuable information for the safety assessment of topically applied products. © 2017 S. Karger AG, Basel.

Geometrical principles of homomeric β-barrels and β-helices: Application to modeling amyloid protofilaments.

PubMed

Hayward, Steven; Milner-White, E James

2017-10-01

Examples of homomeric β-helices and β-barrels have recently emerged. Here we generalize the theory for the shear number in β-barrels to encompass β-helices and homomeric structures. We introduce the concept of the "β-strip," the set of parallel or antiparallel neighboring strands, from which the whole helix can be generated giving it n-fold rotational symmetry. In this context, the shear number is interpreted as the sum around the helix of the fixed register shift between neighboring identical β-strips. Using this approach, we have derived relationships between helical width, pitch, angle between strand direction and helical axis, mass per length, register shift, and number of strands. The validity and unifying power of the method is demonstrated with known structures including α-hemolysin, T4 phage spike, cylindrin, and the HET-s(218-289) prion. From reported dimensions measured by X-ray fiber diffraction on amyloid fibrils, the relationships can be used to predict the register shift and the number of strands within amyloid protofilaments. This was used to construct models of transthyretin and Alzheimer β(40) amyloid protofilaments that comprise a single strip of in-register β-strands folded into a "β-strip helix." Results suggest both stabilization of an individual β-strip helix and growth by addition of further β-strip helices can involve the same pair of sequence segments associating with β-sheet hydrogen bonding at the same register shift. This process would be aided by a repeat sequence. Hence, understanding how the register shift (as the distance between repeat sequences) relates to helical dimensions will be useful for nanotube design. © 2017 Wiley Periodicals, Inc.

Usefulness of pressure-sensitive adhesives as a pretreatment material before application of topical drug formulations and a peeling tape for excess stratum corneum layers.

PubMed

Kikuchi, Keisuke; Todo, Hiroaki; Sugibayashi, Kenji

2014-01-01

Two unique pressure-sensitive adhesive (PSA) tapes (PSA-A, -B) with different adhesive properties of commercial PSAs were prepared and evaluated for their usefulness as a pretreatment material prior to the application of transdermal therapeutic systems or topical drug formulations and also as a peeling agent against excess layers of the stratum corneum. In the present study, in vitro permeation experiments were conducted using vertical type diffusion cells and excised hairless rat or porcine skin from which the stratum corneum had been stripped several times with PSAs. The results obtained revealed that PSA-A and -B had higher stripping or peeling effects than those of the marketed PSAs. Marked changes were observed in skin barrier function before and after stripping using PSAs, and the enhancement effect on the skin permeation of drugs achieved by stripping the stratum corneum was markedly different between the PSAs. PSA-A, in particular, markedly improved skin permeation and the skin concentration of topically applied chemical compounds because it removed many layers of the stratum corneum when skin was stripped only a few times. In contrast, when PSA-B was used to pretreat the skin surface, the extent of skin permeation and concentration of drugs was safely increased because only a few layers of the stratum corneum were removed, even with repeated stripping. The enhancement effect achieved by PSA-B was not as high as that by PSA-A. Thus, stripping with PSA-A can be used as a penetration enhancement tool, whereas PSA-B can be used as a peeling material against excess layers of the stratum corneum.

MSW Transducers

DTIC Science & Technology

1988-11-01

6 - 6 ) and ( 6 - 7 ), with the notation of Figure ( 6 -la), the integral across the nth strip is given by Eq. ( 6 -8). (n-1) p+a/2... calculation . For a finite number of strips, the array is simply truncated without altering the fields. The theoretical expression for hx is given in Eq. ( 6 ... given by Eq. (12) in Reference 2. It is given in this report by Eq. ( 7 -23) or Eq. ( 6 -19). The real average power going into MSW is now a function of z.

Ideal cardiovascular health in childhood-Longitudinal associations with cardiac structure and function: The Special Turku Coronary Risk Factor Intervention Project (STRIP) and the Cardiovascular Risk in Young Finns Study (YFS).

PubMed

Laitinen, Tomi T; Ruohonen, Saku; Juonala, Markus; Magnussen, Costan G; Mikkilä, Vera; Mikola, Hanna; Hutri-Kähönen, Nina; Laitinen, Tomi; Tossavainen, Päivi; Jokinen, Eero; Niinikoski, Harri; Jula, Antti; Viikari, Jorma S A; Rönnemaa, Tapani; Raitakari, Olli T; Pahkala, Katja

2017-03-01

Ideal cardiovascular health (CVH), defined by the American Heart Association, is associated with incident cardiovascular disease in adults. However, association of the ideal CVH in childhood with current and future cardiac structure and function has not been studied. The sample comprised 827 children participating in the longitudinal Special Turku Coronary Risk Factor Intervention Project (STRIP) and The Cardiovascular Risk in Young Finns Study (YFS). In STRIP, complete data on the seven ideal CVH metrics and left ventricular (LV) mass measured with echocardiography were available at the age of 15 (n=321), 17 (n=309) and 19 (n=283) years. In YFS, the cohort comprised children aged 12-18years (n=506) with complete ideal CVH metrics data from childhood and 25years later in adulthood, and echocardiography performed in adulthood. In STRIP, ideal CVH score was inversely associated with LV mass during childhood (P=0.036). In YFS, childhood ideal CVH score was inversely associated with LV mass, LV end-diastolic volume, E/e' ratio, and left atrium end-systolic volume in adulthood (all P<0.01). In addition, improvement of the ideal CVH score between childhood and adulthood was inversely associated with LV mass, LV end-diastolic volume, E/e' ratio, and left atrium end-systolic volume (all P≤0.03). Childhood ideal CVH score has a long-lasting effect on cardiac structure and function, and the association is evident already in childhood. Our findings support targeting the ideal CVH metrics as part of primordial prevention of cardiovascular diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Receiver functions from west Antarctica; crust and mantle properties from POLENET

NASA Astrophysics Data System (ADS)

Aster, R. C.; Chaput, J. A.; Hansen, S. E.; Nyblade, A.; Wiens, D. A.; Huerta, A. D.; Wilson, T. J.; Anandakrishnan, S.

2011-12-01

We use receiver functions to extract crustal thickness and mantle transition zone depths across a wide extent of West Antarctica and the Transantarctic mountains using POLENET data, including recently recovered data from a 14-station West Antarctic Rift Zone transect. An adaptive approach for generating and analyzing P-receiver functions over ice sheets and sedimentary basins (similar to Winberry and Anandakrishnan, 2004) is applied using an extended time multitaper deconvolution algorithm and forward modeling synthetic seismogram fitting. We model P-S receiver functions via a layer stripping methodology (beginning with the ice sheet, if present), and fit increasingly longer sections of synthetic receiver functions to model the multiples observed in the data derived receiver functions. We additionally calculate S-P receiver functions, which provide complementary structural constraints, to generate consistent common conversion point stacks to image crustal and upper mantle discontinuities under West Antarctica. Crust throughout West Antarctica is generally thin (23-29 km; comparable to the U.S. Basin and Range) with relative thickening under the Marie Byrd Land volcanic province (to 32 km) and the Transantarctic Mountains. All constrained west Antarctic crust is substantially thicker than that in the vicinity of Ross Island, where crust as thin as 17 km is inferred in the Terror Rift region.

Effects of smoking on taste: assessment with contact endoscopy and taste strips.

PubMed

Konstantinidis, Iordanis; Chatziavramidis, Angelos; Printza, Athanasia; Metaxas, Spyros; Constantinidis, Jannis

2010-10-01

This study aims to compare the taste function between smokers and nonsmokers with clinical testing, subjective ratings, and contact endoscopy of the tongue. Cross-sectional survey. Data were collected from 38 smokers (mean age 37 years; 25 female, 23 male) and 34 nonsmokers (mean age 33.5 years; 18 female, 16 male). The parameters assessed were the number of fungiform papillae per square centimeter in a noncontact way and their morphology (surface, capillary vessels) by contact endoscopy. The morphology of the filiform papillae has also been assessed. In addition, clinical testing of gustatory function was performed by means of taste strips and subjective intensity ratings of natural taste stimuli. No significant difference was found in clinical testing and intensity ratings between the two study groups. A trend toward significance was found in taste strip results for decreased bitter taste in heavy smokers (P = .06). The number and the size of fungiform papillae did not significantly differ between the study groups. No sex-related differences were observed. Smokers exhibited significantly more keratin structures on the fungiform papillae surface, less tortuous capillary vessels, and a significant distortion of their filiform papillae. Taste function presents significant resistance to smoking, although changes in morphology of fungiform and filiform papillae have been observed especially in heavy smokers. Laryngoscope, 2010.

Vectorization and parallelization of the finite strip method for dynamic Mindlin plate problems

NASA Technical Reports Server (NTRS)

Chen, Hsin-Chu; He, Ai-Fang

1993-01-01

The finite strip method is a semi-analytical finite element process which allows for a discrete analysis of certain types of physical problems by discretizing the domain of the problem into finite strips. This method decomposes a single large problem into m smaller independent subproblems when m harmonic functions are employed, thus yielding natural parallelism at a very high level. In this paper we address vectorization and parallelization strategies for the dynamic analysis of simply-supported Mindlin plate bending problems and show how to prevent potential conflicts in memory access during the assemblage process. The vector and parallel implementations of this method and the performance results of a test problem under scalar, vector, and vector-concurrent execution modes on the Alliant FX/80 are also presented.

Tunneling Spectroscopy of Quantum Hall States in Bilayer Graphene

NASA Astrophysics Data System (ADS)

Wang, Ke; Harzheim, Achim; Watanabe, Kenji; Taniguchi, Takashi; Kim, Philip

In the quantum Hall (QH) regime, ballistic conducting paths along the physical edges of a sample appear, leading to quantized Hall conductance and vanishing longitudinal magnetoconductance. These QH edge states are often described as ballistic compressible strips separated by insulating incompressible strips, the spatial profiles of which can be crucial in understanding the stability and emergence of interaction driven QH states. In this work, we present tunneling transport between two QH edge states in bilayer graphene. Employing locally gated device structure, we guide and control the separation between the QH edge states in bilayer graphene. Using resonant Landau level tunneling as a spectroscopy tool, we measure the energy gap in bilayer graphene as a function of displacement field and probe the emergence and evolution of incompressible strips.

Functional and Evolutionary Analysis of the CASPARIAN STRIP MEMBRANE DOMAIN PROTEIN Family1[C][W

PubMed Central

Roppolo, Daniele; Boeckmann, Brigitte; Pfister, Alexandre; Boutet, Emmanuel; Rubio, Maria C.; Dénervaud-Tendon, Valérie; Vermeer, Joop E.M.; Gheyselinck, Jacqueline; Xenarios, Ioannis; Geldner, Niko

2014-01-01

CASPARIAN STRIP MEMBRANE DOMAIN PROTEINS (CASPs) are four-membrane-span proteins that mediate the deposition of Casparian strips in the endodermis by recruiting the lignin polymerization machinery. CASPs show high stability in their membrane domain, which presents all the hallmarks of a membrane scaffold. Here, we characterized the large family of CASP-like (CASPL) proteins. CASPLs were found in all major divisions of land plants as well as in green algae; homologs outside of the plant kingdom were identified as members of the MARVEL protein family. When ectopically expressed in the endodermis, most CASPLs were able to integrate the CASP membrane domain, which suggests that CASPLs share with CASPs the propensity to form transmembrane scaffolds. Extracellular loops are not necessary for generating the scaffold, since CASP1 was still able to localize correctly when either one of the extracellular loops was deleted. The CASP first extracellular loop was found conserved in euphyllophytes but absent in plants lacking Casparian strips, an observation that may contribute to the study of Casparian strip and root evolution. In Arabidopsis (Arabidopsis thaliana), CASPL showed specific expression in a variety of cell types, such as trichomes, abscission zone cells, peripheral root cap cells, and xylem pole pericycle cells. PMID:24920445

Functional and Evolutionary Analysis of the CASPARIAN STRIP MEMBRANE DOMAIN PROTEIN Family.

PubMed

Roppolo, Daniele; Boeckmann, Brigitte; Pfister, Alexandre; Boutet, Emmanuel; Rubio, Maria C; Dénervaud-Tendon, Valérie; Vermeer, Joop E M; Gheyselinck, Jacqueline; Xenarios, Ioannis; Geldner, Niko

2014-08-01

CASPARIAN STRIP MEMBRANE DOMAIN PROTEINS (CASPs) are four-membrane-span proteins that mediate the deposition of Casparian strips in the endodermis by recruiting the lignin polymerization machinery. CASPs show high stability in their membrane domain, which presents all the hallmarks of a membrane scaffold. Here, we characterized the large family of CASP-like (CASPL) proteins. CASPLs were found in all major divisions of land plants as well as in green algae; homologs outside of the plant kingdom were identified as members of the MARVEL protein family. When ectopically expressed in the endodermis, most CASPLs were able to integrate the CASP membrane domain, which suggests that CASPLs share with CASPs the propensity to form transmembrane scaffolds. Extracellular loops are not necessary for generating the scaffold, since CASP1 was still able to localize correctly when either one of the extracellular loops was deleted. The CASP first extracellular loop was found conserved in euphyllophytes but absent in plants lacking Casparian strips, an observation that may contribute to the study of Casparian strip and root evolution. In Arabidopsis (Arabidopsis thaliana), CASPL showed specific expression in a variety of cell types, such as trichomes, abscission zone cells, peripheral root cap cells, and xylem pole pericycle cells. © 2014 American Society of Plant Biologists. All Rights Reserved.

Visual method for detecting critical damage in railway contact strips

NASA Astrophysics Data System (ADS)

Judek, S.; Skibicki, J.

2018-05-01

Ensuring an uninterrupted supply of power in the electric traction is vital for the safety of this important transport system. For this purpose, monitoring and diagnostics of the technical condition of the vehicle’s power supply elements are becoming increasingly common. This paper presents a new visual method for detecting contact strip damage, based on measurement and analysis of the movement of the overhead contact line (OCL) wire. A measurement system configuration with a 2D camera was proposed. The experimental method has shown that contact strips damage can be detected by transverse displacement signal analysis. It has been proven that the velocity signal numerically established on that basis has a comparable level in the case of identical damage, regardless of its location on the surface of the contact strip. The proposed method belongs to the group of contact-less measurements, so it does not require interference with the structure of the catenary network nor the mounting of sensors in its vicinity. Measurement of displacements of the contact wire in 2D space makes it possible to combine the functions of existing diagnostic stands assessing the correctness of the mean contact force control adjustment of the current collector with the elements of the contact strip diagnostics, which involves detecting their damage which may result in overhead contact line rupture.

Multi-layer topological transmissions of spoof surface plasmon polaritons.

PubMed

Pan, Bai Cao; Zhao, Jie; Liao, Zhen; Zhang, Hao Chi; Cui, Tie Jun

2016-03-04

Spoof surface plasmon polaritons (SPPs) in microwave frequency provide a high field confinement in subwavelength scale and low-loss and flexible transmissions, which have been widely used in novel transmission waveguides and functional devices. To play more important roles in modern integrated circuits and systems, it is necessary and helpful for the SPP modes to propagate among different layers of devices and chips. Owing to the highly confined property and organized near-field distribution, we show that the spoof SPPs could be easily transmitted from one layer into another layer via metallic holes and arc-shaped transitions. Such designs are suitable for both the ultrathin and flexible single-strip SPP waveguide and double-strip SPP waveguide for active SPP devices. Numerical simulations and experimental results demonstrate the broadband and high-efficiency multi-layer topological transmissions with controllable absorption that is related to the superposition area of corrugated metallic strips. The transmission coefficient of single-strip SPP waveguide is no worse than -0.8 dB within frequency band from 2.67 GHz to 10.2 GHz while the transmission of double-strip SPP waveguide keeps above -1 dB within frequency band from 2.26 GHz to 11.8 GHz. The proposed method will enhance the realizations of highly complicated plasmonic integrated circuits.

Investigation of multilayer magnetic domain lattice file

NASA Technical Reports Server (NTRS)

Torok, E. J.; Kamin, M.; Tolman, C. H.

1980-01-01

The feasibility of the self structured multilayered bubble domain memory as a mass memory medium for satellite applications is examined. Theoretical considerations of multilayer bubble supporting materials are presented, in addition to the experimental evaluation of current accessed circuitry for various memory functions. The design, fabrication, and test of four device designs is described, and a recommended memory storage area configuration is presented. Memory functions which were demonstrated include the current accessed propagation of bubble domains and stripe domains, pinning of stripe domain ends, generation of single and double bubbles, generation of arrays of coexisting strip and bubble domains in a single garnet layer, and demonstration of different values of the strip out field for single and double bubbles indicating adequate margins for data detection. All functions necessary to develop a multilayer self structured bubble memory device were demonstrated in individual experiments.

Automatic Extraction of High-Resolution Rainfall Series from Rainfall Strip Charts

NASA Astrophysics Data System (ADS)

Saa-Requejo, Antonio; Valencia, Jose Luis; Garrido, Alberto; Tarquis, Ana M.

2015-04-01

Soil erosion is a complex phenomenon involving the detachment and transport of soil particles, storage and runoff of rainwater, and infiltration. The relative magnitude and importance of these processes depends on a host of factors, including climate, soil, topography, cropping and land management practices among others. Most models for soil erosion or hydrological processes need an accurate storm characterization. However, this data are not always available and in some cases indirect models are generated to fill this gap. In Spain, the rain intensity data known for time periods less than 24 hours back to 1924 and many studies are limited by it. In many cases this data is stored in rainfall strip charts in the meteorological stations but haven't been transfer in a numerical form. To overcome this deficiency in the raw data a process of information extraction from large amounts of rainfall strip charts is implemented by means of computer software. The method has been developed that largely automates the intensive-labour extraction work based on van Piggelen et al. (2011). The method consists of the following five basic steps: 1) scanning the charts to high-resolution digital images, 2) manually and visually registering relevant meta information from charts and pre-processing, 3) applying automatic curve extraction software in a batch process to determine the coordinates of cumulative rainfall lines on the images (main step), 4) post processing the curves that were not correctly determined in step 3, and 5) aggregating the cumulative rainfall in pixel coordinates to the desired time resolution. A colour detection procedure is introduced that automatically separates the background of the charts and rolls from the grid and subsequently the rainfall curve. The rainfall curve is detected by minimization of a cost function. Some utilities have been added to improve the previous work and automates some auxiliary processes: readjust the bands properly, merge bands when those have been scanned in two parts, detect and cut the borders of bands not used (demanded by the software). Also some variations in which colour system is tried basing in HUE or RGB colour have been included. Thanks to apply this digitization rainfall strip charts 209 station-years of three locations in the centre of Spain have been transformed to long-term rainfall time series with 5-min resolution. References van Piggelen, H.E., T. Brandsma, H. Manders, and J. F. Lichtenauer, 2011: Automatic Curve Extraction for Digitizing Rainfall Strip Charts. J. Atmos. Oceanic Technol., 28, 891-906. Acknowledgements Financial support for this research by DURERO Project (Env.C1.3913442) is greatly appreciated.

An ex vivo human skin model for studying skin barrier repair.

PubMed

Danso, Mogbekeloluwa O; Berkers, Tineke; Mieremet, Arnout; Hausil, Farzia; Bouwstra, Joke A

2015-01-01

In the studies described in this study, we introduce a novel ex vivo human skin barrier repair model. To develop this, we removed the upper layer of the skin, the stratum corneum (SC) by a reproducible cyanoacrylate stripping technique. After stripping the explants, they were cultured in vitro to allow the regeneration of the SC. We selected two culture temperatures 32 °C and 37 °C and a period of either 4 or 8 days. After 8 days of culture, the explant generated SC at a similar thickness compared to native human SC. At 37 °C, the early and late epidermal differentiation programmes were executed comparably to native human skin with the exception of the barrier protein involucrin. At 32 °C, early differentiation was delayed, but the terminal differentiation proteins were expressed as in stripped explants cultured at 37 °C. Regarding the barrier properties, the SC lateral lipid organization was mainly hexagonal in the regenerated SC, whereas the lipids in native human SC adopt a more dense orthorhombic organization. In addition, the ceramide levels were higher in the cultured explants at 32 °C and 37 °C than in native human SC. In conclusion, we selected the stripped ex vivo skin model cultured at 37 °C as a candidate model to study skin barrier repair because epidermal and SC characteristics mimic more closely the native human skin than the ex vivo skin model cultured at 32 °C. Potentially, this model can be used for testing formulations for skin barrier repair. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Closeup view of leeds and northrup strip chart recorders used ...

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

Close-up view of leeds and northrup strip chart recorders used to indicate power usage on certain portions of the system. Note model board builders plaque which reads Kellogg Switchboard and Supply Company- Chicago, USA at left center of photograph. - Thirtieth Street Station, Load Dispatch Center, Thirtieth & Market Streets, Railroad Station, Amtrak (formerly Pennsylvania Railroad Station), Philadelphia, Philadelphia County, PA

Post-Palaeozoic evolution of weathered landsurfaces in Uganda by tectonically controlled deep weathering and stripping

NASA Astrophysics Data System (ADS)

Taylor, R. G.; Howard, K. W. F.

1998-11-01

A model for the evolution of weathered landsurfaces in Uganda is developed using available geotectonic, climatic, sedimentological and chronological data. The model demonstrates the pivotal role of tectonic uplift in inducing cycles of stripping, and tectonic quiescence for cycles of deep weathering. It is able to account for the development of key landforms, such as inselbergs and duricrust-capped plateaux, which previous hypotheses of landscape evolution that are based on climatic or eustatic controls are unable to explain. Development of the Ugandan landscape is traced back to the Permian. Following late Palaeozoic glaciation, a trend towards warmer and more humid climates through the Mesozoic enabled deep weathering of the Jurassic/mid-Cretaceous surface in Uganda during a period of prolonged tectonic quiescence. Uplift associated with the opening South Atlantic Ocean terminated this cycle and instigated a cycle of stripping between the mid-Cretaceous and early Miocene. Deep weathering on the succeeding Miocene to recent (African) surface has occurred from Miocene to present but has been interrupted in the areas adjacent to the western rift where development of a new drainage base level has prompted cycles of stripping in the Miocene and Pleistocene.

An experimental and theoretical study of structural damping in compliant foil bearings

NASA Technical Reports Server (NTRS)

Ku, C.-P. Roger

1994-01-01

This paper describes an experimental investigation into the dynamic characteristics of corrugated foil (bump foil) strips used in compliant surface foil bearings. This study provided and opportunity to quantify the structural damping of bump foil strips. The experimental data were compared to results obtained by a theoretical model developed earlier. The effects of bearing design parameters, such as static loads, dynamic displacement amplitudes, bump configurations, pivot locations, surface coatings, and lubricant were also evaluated. An understanding of the dynamic characteristics of bump foil strips resulting from this work offers designers a means for enhancing the design of high-performance compliant foil bearings.

Sustainable in-well vapor stripping: A design, analytical model, and pilot study for groundwater remediation

NASA Astrophysics Data System (ADS)

Sutton, Patrick T.; Ginn, Timothy R.

2014-12-01

A sustainable in-well vapor stripping system is designed as a cost-effective alternative for remediation of shallow chlorinated solvent groundwater plumes. A solar-powered air compressor is used to inject air bubbles into a monitoring well to strip volatile organic compounds from a liquid to vapor phase while simultaneously inducing groundwater circulation around the well screen. An analytical model of the remediation process is developed to estimate contaminant mass flow and removal rates. The model was calibrated based on a one-day pilot study conducted in an existing monitoring well at a former dry cleaning site. According to the model, induced groundwater circulation at the study site increased the contaminant mass flow rate into the well by approximately two orders of magnitude relative to ambient conditions. Modeled estimates for 5 h of pulsed air injection per day at the pilot study site indicated that the average effluent concentrations of dissolved tetrachloroethylene and trichloroethylene can be reduced by over 90% relative to the ambient concentrations. The results indicate that the system could be used cost-effectively as either a single- or multi-well point technology to substantially reduce the mass of dissolved chlorinated solvents in groundwater.

Recovery of isopropyl alcohol from waste solvent of a semiconductor plant.

PubMed

Lin, Sheng H; Wang, Chuen S

2004-01-30

An important waste solvent generated in the semiconductor manufacturing process was characterized by high isopropyl alcohol (IPA) concentration over 65%, other organic pollutants and strong color. Because of these characteristics, IPA recovery was deemed as a logic choice for tackling this waste solvent. In the present work, an integrated method consisting of air stripping in conjunction with condensation and packed activated carbon fiber (ACF) adsorption for dealing with this waste solvent. The air stripping with proper stripping temperature control was employed to remove IPA from the waste solvent and the IPA vapor in the gas mixture was condensed out in a side condenser. The residual IPA remaining in the gas mixture exiting the side condenser was efficiently removed in a packed ACF column. The air stripping with condensation was able to recover up to 93% of total IPA in the initial waste solvent. The residual IPA in the gas mixture, representing less than 3% of the initial IPA, was efficiently captured in the packed ACF column. Experimental tests were conducted to examine the performances of each unit and to identify the optimum operating conditions. Theoretical modeling of the experimental IPA breakthrough curves was also undertaken using a macroscopic model. The verified breakthrough model significantly facilitates the adsorption column design. The recovered IPA was found to be of high purity and could be considered for reuse. Copyright 2003 Elsevier B.V.

The role of microglia in synaptic stripping and synaptic degeneration: a revised perspective

PubMed Central

Hugh Perry, V; O'Connor, Vincent

2010-01-01

Chronic neurodegenerative diseases of the CNS (central nervous system) are characterized by the loss of neurons. There is, however, growing evidence to show that an early stage of this process involves degeneration of presynaptic terminals prior to the loss of the cell body. Synaptic plasticity in CNS pathology has been associated with microglia and the phenomenon of synaptic stripping. We review here the evidence for the involvement of microglia in synaptic stripping and synapse degeneration and we conclude that this is a case of guilt by association. In disease models of chronic neurodegeneration, there is no evidence that microglia play an active role in either synaptic stripping or synapse degeneration, but the degeneration of the synapse and the envelopment of a degenerating terminal appears to be a neuron autonomous event. We highlight here some of the gaps in our understanding of synapse degeneration in chronic neurodegenerative disease. PMID:20967131

Air Stripping Designs and Reactive Water Purification Processes for the Lunar Surface

NASA Technical Reports Server (NTRS)

Boul, Peter J.; Lange, Kevin; Conger, Bruce; Anderson, Molly

2010-01-01

Air stripping designs are considered to reduce the presence of volatile organic compounds in the purified water. Components of the wastewater streams are ranked by Henry's Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Distillation processes are modeled in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates. An evaluation of reactive distillation and air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

Automated Mounting Bias Calibration for Airborne LIDAR System

NASA Astrophysics Data System (ADS)

Zhang, J.; Jiang, W.; Jiang, S.

2012-07-01

Mounting bias is the major error source of Airborne LIDAR system. In this paper, an automated calibration method for estimating LIDAR system mounting parameters is introduced. LIDAR direct geo-referencing model is used to calculate systematic errors. Due to LIDAR footprints discretely sampled, the real corresponding laser points are hardly existence among different strips. The traditional corresponding point methodology does not seem to apply to LIDAR strip registration. We proposed a Virtual Corresponding Point Model to resolve the corresponding problem among discrete laser points. Each VCPM contains a corresponding point and three real laser footprints. Two rules are defined to calculate tie point coordinate from real laser footprints. The Scale Invariant Feature Transform (SIFT) is used to extract corresponding points in LIDAR strips, and the automatic flow of LIDAR system calibration based on VCPM is detailed described. The practical examples illustrate the feasibility and effectiveness of the proposed calibration method.

Effect of Initial Stress on the Dynamic Response of a Multi-Layered Plate-Strip Subjected to an Arbitrary Inclined Time-Harmonic Force

NASA Astrophysics Data System (ADS)

Daşdemir, A.

2017-08-01

The forced vibration of a multi-layered plate-strip with initial stress under the action of an arbitrary inclined time-harmonic force resting on a rigid foundation is considered. Within the framework of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic waves in initially stressed bodies (TLTEWISB), a mathematical modelling is presented in plane strain state. It is assumed that there exists the complete contact interaction at the interface between the layers and the materials of the layer are linearly elastic, homogeneous and isotropic. The governing system of the partial differential equations of motion for the considered problem is solved approximately by employing the Finite Element Method (FEM). Further, the influence of the initial stress parameter on the dynamic response of the plate-strip is presented.

Multiple period s-p hybridization in nano-strip embedded photonic crystal.

PubMed

Han, Seunghoon; Lee, Il-Min; Kim, Hwi; Lee, Byoungho

2005-04-04

We report and analyze hybridization of s-state and p-state modes in photonic crystal one-dimensional defect cavity array. When embedding a nano-strip into a dielectric rod photonic crystal, an effective cavity array is made, where each cavity possesses two cavity modes: s-state and p-state. The two modes are laterally even versus the nano-strip direction, and interact with each other, producing defect bands, of which the group velocity becomes zero within the first Brillouin zone. We could model and describe the phenomena by using the tight-binding method, well agreeing with the plane-wave expansion method analysis. We note that the reported s- and p-state mode interaction corresponds to the hybridization of atomic orbital in solid-state physics. The concept of multiple period s-p hybridization and the proposed model can be useful for analyzing and developing novel photonic crystal waveguides and devices.

Polyhydric polymer-functionalized fluorescent probe with enhanced aqueous solubility and specific ion recognition: A test strips-based fluorimetric strategy for the rapid and visual detection of Fe3+ ions.

PubMed

Duan, Zhiqiang; Zhang, Chunxian; Qiao, Yuchun; Liu, Fengjuan; Wang, Deyan; Wu, Mengfan; Wang, Ke; Lv, Xiaoxia; Kong, Xiangmu; Wang, Hua

2017-08-01

A polyhydric polymer-functionalized probe with enhanced aqueous solubility was designed initially by coupling 1-pyrenecarboxyaldehyde (Pyr) onto poly(vinyl alcohol) (PVA) via the one-step condensation reaction. Polyhydric PVA polymer chains could facilitate the Pyr fluorophore with largely improved aqueous solubility and especially strong cyan fluorescence. Importantly, the fluorescence of the PVA-Pyr probes could thereby be quenched specifically by Fe 3+ ions through the strong PVA-Fe 3+ interaction triggering the polymeric probe aggregation. Furthermore, a test strips-based fluorimetric method was developed with the stable and uniform probe distribution by taking advantage of the unique film-forming ability and the depression capacity of "coffee-stain" effects of PVA matrix. The as-developed test strips could allow for the rapid and visual detections of Fe 3+ ions simply by a dipping way, showing a linear concentration range of 5.00-300μM, with the detection limit of 0.73μM. Moreover, the proposed method was applied to the evaluation of Fe 3+ ions in natural water samples, showing the analysis performances better or comparable to those of current detection techniques. This test strips-based fluorimetric strategy promises the extensive applications for the rapid on-site monitoring of Fe 3+ ions in environmental water and the outdoor finding of the potential iron mines. Copyright © 2017 Elsevier B.V. All rights reserved.

Hierarchic models for laminated plates

NASA Technical Reports Server (NTRS)

Szabo, Barna A.; Actis, Ricardo L.

1991-01-01

The research conducted in the formulation of hierarchic models for laminated plates is described. The work is an extension of the work done for laminated strips. The use of a single parameter, beta, is investigated that represents the degree to which the equilibrium equations of three dimensional elasticity are satisfied. The powers of beta identify members in the hierarchic sequence. Numerical examples that were analyzed with the proposed sequence of models are included. The results obtained for square plates with uniform loading and homogeneous boundary conditions are very encouraging. Several cross-ply and angle-ply laminates were evaluated and the results compared with those of the fully three dimensional model, computed using MSC/PROBE, and with previously reported work on laminated strips.

Snap-buckling in asymmetrically constrained elastic strips

NASA Astrophysics Data System (ADS)

Sano, Tomohiko G.; Wada, Hirofumi

2018-01-01

When a flat elastic strip is compressed along its axis, it is bent in one of two possible directions via spontaneous symmetry breaking, forming a cylindrical arc. This is a phenomenon well known as Euler buckling. When this cylindrical section is pushed in the other direction, the bending direction can suddenly reverse. This instability is called "snap-through buckling" and is one of the elementary shape transitions in a prestressed thin structure. Combining experiments and theory, we study snap-buckling of an elastic strip with one end hinged and the other end clamped. These asymmetric boundary constraints break the intrinsic symmetry of the strip, generating mechanical behaviors, including largely hysteretic but reproducible force responses and switchlike discontinuous shape changes. We establish the set of exact analytical solutions to fully explain all our major experimental and numerical findings. Asymmetric boundary conditions arise naturally in diverse situations when a thin object is in contact with a solid surface at one end. The introduction of asymmetry through boundary conditions yields new insight into complex and programmable functionalities in material and industrial design.

Smartphone-based analysis of biochemical tests for health monitoring support at home.

PubMed

Velikova, Marina; Smeets, Ruben L; van Scheltinga, Josien Terwisscha; Lucas, Peter J F; Spaanderman, Marc

2014-09-01

In the context of home-based healthcare monitoring systems, it is desirable that the results obtained from biochemical tests - tests of various body fluids such as blood and urine - are objective and automatically generated to reduce the number of man-made errors. The authors present the StripTest reader - an innovative smartphone-based interpreter of biochemical tests based on paper-based strip colour using image processing techniques. The working principles of the reader include image acquisition of the colour strip pads using the camera phone, analysing the images within the phone and comparing them with reference colours provided by the manufacturer to obtain the test result. The detection of kidney damage was used as a scenario to illustrate the application of, and test, the StripTest reader. An extensive evaluation using laboratory and human urine samples demonstrates the reader's accuracy and precision of detection, indicating the successful development of a cheap, mobile and smart reader for home-monitoring of kidney functioning, which can facilitate the early detection of health problems and a timely treatment intervention.

Soil hydrology of agroforestry systems: Competition for water or positive tree-crops interactions?

NASA Astrophysics Data System (ADS)

Gerjets, Rowena; Richter, Falk; Jansen, Martin; Carminati, Andrea

2017-04-01

In dry periods during the growing season crops may suffer from severe water stress. The question arises whether the alternation of crop and tree strips might enhance and sustain soil water resources available for crops during drought events. Trees reduce wind exposure, decreasing the potential evapotranspiration of crops and soils; additionally hydraulic lift from the deep roots of trees to the drier top soil might provide additional water for shallow-rooted crops. To understand the above and belowground water relations of agroforestry systems, we measured soil moisture and soil water potential in crop strips as a function of distance to the trees at varying depth as well as meteorological parameters. At the agroforestry site Reiffenhausen, Lower Saxony, Germany, two different tree species are planted, each in one separated tree strip: willow breed Tordis ((Salix viminalis x Salix Schwerinii) x Salix viminalis) and poplar clone Max 1 (Populus nigra x Populus maximowiczii). In between the tree strips a crop strip of 24 m width was established with annual crop rotation, managed the same way as the reference site. During a drought period in May 2016 with less than 2 mm rain in four weeks, an overall positive effect on hydrological conditions of the agroforestry system was observed. The results show that trees shaded the soil surface, lowering the air temperature and further increasing the soil moisture in the crop strips compared to the reference site, which was located far from the trees. At the reference site the crops took up water in the upper soil (<20 cm depth); after the soil reached water potentials below -100 kPa, root water uptake moved to deeper soil layers (<40 cm). Because of the higher wind and solar radiation exposure the reference soil profile was severely dried out. Also in the crop strips of the agroforestry system, crops took up water in the upper soil. However, the lower soil layers remained wet for an extended period of time. The tree strips reduced the wind speed, hence lowering evapotranspiration in the crop strip. The plot was not aligned directly to North and we observed steeper soil water potential gradients in the part of the crop strip more exposed to sunlight. The two tree species behaved differently. The poplar strips showed more marked diurnal changes in soil water potential, with fast drying during daytime and rewetting during nighttime. We suppose that the rewetting during nighttime was caused by hydraulic lift, which supports passively the drier upper soil with water from the wetter, lower soil layers. This experimental study shows the importance of above- and belowground tree-crop interactions and demonstrate the positive effect of tree strips in reducing drought stress in crops.

Type of oral solid medication packaging and medication preparation time in nursing homes: A direct observation study.

PubMed

Cready, C M; Hudson, C; Dreyer, K

2017-12-01

Medication administration is a substantial portion of the workday in nursing homes, with the medication preparation step being the most time-consuming. However, little is known about how medication preparation time is affected by the type of packaging used for oral solid medications (ie, tablets/capsules). We examined the effects of two types of packaging. As fewer steps are associated with strip packaging compared to bingo card packaging, we hypothesized that the increase in medication preparation seconds per resident with each additional oral solid medication would be smaller when strip packaging was used. A total of 430 medication preparations conducted by eight nurses during the regularly scheduled morning medication administration period in two nursing homes-using strip packaging and bingo card packaging, respectively-were observed. Each medication preparation observation was matched to its corresponding medication administration record and observations averaged across resident. Using the resident sample (N=149), we estimated three regression models (adjusting the standard errors for the clustering of resident by nurse). The first model regressed medication preparation seconds on the number of oral solid medications. The second model added the type of packaging used and the control variables (type of unit [long-term care, post-acute care], the number of one-half pills and the dosage form diversity in the preparation). To test our hypothesis, the third model added an interaction term between the number of oral solid medications and the type of packaging used. As hypothesized, all else equal, the number of oral solid medications tended to increase medication preparation time per resident in both nursing homes, but the increase was smaller in the strip packaging nursing home (P<.05). Each additional oral solid medication in the bingo card packaging nursing home increased medication preparation by an average of 13 seconds (b=13.077), whereas each oral solid medication administered in the strip packaging nursing home increased medication preparation by an average of only 8 seconds (13.077-5.092=7.985). This is a difference on average of about 5 seconds per oral solid medication. To our knowledge, we were the first to examine the effect of type of oral solid medication packaging on medication preparation time in nursing homes. Type of packaging matters. The time saved using strip packaging (vs bingo card packaging) has implications for quality of care and the movement towards person-centred care in the nursing home sector. Nurses (or other staff tasked with medication preparation) in nursing homes using strip packaging potentially have more time to devote to nurturing a relationship with the resident. However, time saved in medication preparation by strip packaging is counterproductive if a serious error results. Thus, future studies should investigate the effects of type of packaging on medication preparation errors. © 2017 John Wiley & Sons Ltd.

The warped disk of Centaurus A in the near-infrared

NASA Technical Reports Server (NTRS)

Quillen, A. C.; Graham, James R.; Frogel, Jay A.

1993-01-01

We present infrared images of Cen A (NGC 5128) in the J, H, and K bands. The infrared morphology is primarily determined by the presence of a thin absorptive warped disk. By integrating the light of the underlying prolate galaxy through such a disk, we construct models which we compare with infrared and X-ray data. The geometry of the warped disk needed to fit the IR data is consistent with a warped disk which has evolved as a result of differential precession in a prolate potential. The disk has an inclination, with respect to the principal axis of the underlying elliptical galaxy, that is higher at larger radii than in the inner region. A scenario is proposed where a small gas-rich galaxy infalling under the force of dynamical friction is tidally stripped. Stripping occurs at different times during its infall. The orientation of the resulting gas disk depends upon the angular momentum of the infalling galaxy. We find that the resulting precession angle of the disk is well described by the precession model, but that the inclination angle may vary as a function of radius. We propose an orbit for the infalling galaxy that is consistent with the geometry of the warped disk needed to fit our infrared data, and rotation observed in the outer part of the galaxy.

Combined Experimental and Theoretical Investigations on Optical Activities of Möbius Aromatic and Möbius Antiaromatic Hexaphyrin Phosphorus Complexes.

PubMed

Mori, Tadashi; Tanaka, Takayuki; Higashino, Tomohiro; Yoshida, Kota; Osuka, Atsuhiro

2016-06-23

Intrinsically chiral Möbius aromatic [28]hexaphyrin monophosphorus(V) and Möbius antiaromatic [30]hexaphyrin bisphosphorus(V) complexes have been optically resolved and their absolute configurations (ACs) were determined by combined experimental and theoretical investigations on their circular dichroisms (CDs). First elutes in chiral HPLC exhibited strong positive Cotton effects (CEs) at the B-band, characteristic for the ML configurations in their Möbius strips. Weak CEs at the Q-band, if attainable, complemented their AC assignment. The whole CD pattern and intensity were well reproduced by time-dependent approximate coupled cluster theory using model systems that omit five outward meso-aryl substituents (inward-meso-retained model), providing a solid basis for AC assignment. The cost efficient TD-DFT method with appropriate functionals for fully substituted (nontruncated) complexes well reproduced CEs around the B-band (but less satisfactory at the Q-band), also allows the rapid AC estimation for their Möbius strips. Observed difference in CDs between aromatic and antiaromatic hexaphyrins were better interpreted by their shifts in energy levels and altered interactions of relevant molecular orbitals, rather than small differences in Möbius geometries nor aromatic/antiaromatic character, despite the correlations recently claimed in planar π-systems.

Explorations in fuzzy physics and non-commutative geometry

NASA Astrophysics Data System (ADS)

Kurkcuoglu, Seckin

Fuzzy spaces arise as discrete approximations to continuum manifolds. They are usually obtained through quantizing coadjoint orbits of compact Lie groups and they can be described in terms of finite-dimensional matrix algebras, which for large matrix sizes approximate the algebra of functions of the limiting continuum manifold. Their ability to exactly preserve the symmetries of their parent manifolds is especially appealing for physical applications. Quantum Field Theories are built over them as finite-dimensional matrix models preserving almost all the symmetries of their respective continuum models. In this dissertation, we first focus our attention to the study of fuzzy supersymmetric spaces. In this regard, we obtain the fuzzy supersphere S2,2F through quantizing the supersphere, and demonstrate that it has exact supersymmetry. We derive a finite series formula for the *-product of functions over S2,2F and analyze the differential geometric information encoded in this formula. Subsequently, we show that quantum field theories on S2,2F are realized as finite-dimensional supermatrix models, and in particular we obtain the non-linear sigma model over the fuzzy supersphere by constructing the fuzzy supersymmetric extensions of a certain class of projectors. We show that this model too, is realized as a finite-dimensional supermatrix model with exact supersymmetry. Next, we show that fuzzy spaces have a generalized Hopf algebra structure. By focusing on the fuzzy sphere, we establish that there is a *-homomorphism from the group algebra SU(2)* of SU(2) to the fuzzy sphere. Using this and the canonical Hopf algebra structure of SU(2)* we show that both the fuzzy sphere and their direct sum are Hopf algebras. Using these results, we discuss processes in which a fuzzy sphere with angular momenta J splits into fuzzy spheres with angular momenta K and L. Finally, we study the formulation of Chern-Simons (CS) theory on an infinite strip of the non-commutative plane. We develop a finite-dimensional matrix model, whose large size limit approximates the CS theory on the infinite strip, and show that there are edge observables in this model obeying a finite-dimensional Lie algebra, that resembles the Kac-Moody algebra.

What's Happening to the American Family?

ERIC Educational Resources Information Center

Eisenberg, Leon

In the aftermath of the Industrial Revolution, the American family has been stripped of two of its traditional social functions: serving as a unit for economic production and as a school for the vocational training of children. The first function has been usurped by commercial firms, the second by the state. Some functions remain: physically and…

Free-edge effects in laminates under extension, bending and twisting. II - Sublaminate/layer modeling and analysis

NASA Technical Reports Server (NTRS)

Yin, Wan-Lee

1992-01-01

The stress-function-based variational method of Yin (1991) is extended and modified into a combined layer/sublaminate approach applicable to a laminated strip composed of a large number of differently orientated, anisotropic elastic plies. Lekhnitskii's (1963) stress functions are introduced into two interior layers adjacent to a particular interface. The remaining layers are grouped into an upper sublaminate and a lower sublaminate. The stress functions are expanded in truncated power series of the thickness coordinate, and the differential equations governing the coefficient functions are derived by using the complementary virtual work principle. The layer/sublaminate approach limits the dimension of the eigenvalue problem to a fixed number irrespective of the number of layers in the sublaminate, so that reasonably accurate solutions of the interlaminar stresses can be computed with extreme ease. For symmetric, four-layer, angle-ply and cross-ply laminates, a comparison of the previous analysis results based on the pure layer model and new results based on two different layer/sublaminate models indicates reasonable over-all agreement in the interlaminar stresses and superior agreement in the total peeling and shearing force.

Frequency of self-monitoring blood glucose and attainment of HbA1c target values.

PubMed

Elgart, Jorge F; González, Lorena; Prestes, Mariana; Rucci, Enzo; Gagliardino, Juan J

2016-02-01

Test strips for self-monitoring of blood glucose (SMBG) represent in Argentina, around 50 % of diabetes treatment cost; the frequency of their use is closely associated with hyperglycemia treatment. However, the favorable impact of SMBG on attainment of HbA1c goal in different treatment conditions remains controversial. We therefore attempted to estimate the relationship between use of SMBG test strips and degree of attainment of metabolic control in an institution of our social security subsector (SSS) in which provision is fully covered and submitted to a regular audit system. Observational retrospective study using information of 657 patients with T2DM (period 2009-2010) from the database of the Diabetes and Other Cardiovascular Risk Factors Program (DICARO) of one institution of our SSS. DICARO provides-with an audit system-100 % coverage for all drugs and keeps records of clinical, metabolic and treatment data from every patient. The average monthly test strips/patient used for SMBG increased as a function of treatment intensification: Monotherapy with oral antidiabetic drugs (OAD) < combined OAD therapy < insulin treatment. In every condition, the number was larger in people with target HbA1c levels. Test strips represented the larger percentage of total prescription cost. In our population, the type of hyperglycemia treatment was the main driver of test strip use for SMBG; in every condition tested, targeted HbA1c values were associated with greater strip use. Patient education and prescription audit may optimize its use and treatment outcomes.

Physical drivers of galaxies' cold-gas content: exploring environmental and evolutionary effects with Dark Sage

NASA Astrophysics Data System (ADS)

Stevens, Adam R. H.; Brown, Toby

2017-10-01

We combine the latest spectrally stacked data of 21-cm emission from the Arecibo Legacy Fast ALFA survey with an updated version of the Dark Sage semi-analytic model to investigate the relative contributions of secular and environmental astrophysical processes on shaping the H I fractions and quiescence of galaxies in the local Universe. We calibrate the model to match the observed mean H I fraction of all galaxies as a function of stellar mass. Without consideration of stellar feedback, disc instabilities and active galactic nuclei, we show how the slope and normalization of this relation would change significantly. We find Dark Sage can reproduce the relative impact that halo mass is observed to have on satellites' H I fractions and quiescent fraction. However, the model satellites are systematically gas-poor. We discuss how this could be affected by satellite-central cross-contamination from the group-finding algorithm applied to the observed galaxies, but that it is not the full story. From our results, we suggest the anticorrelation between satellites' H I fractions and host halo mass, seen at fixed stellar mass and fixed specific star formation rate, can be attributed almost entirely to ram-pressure stripping of cold gas. Meanwhile, stripping of hot gas from around the satellites drives the correlation of quiescent fraction with halo mass at fixed stellar mass. Further detail in the modelling of galaxy discs' centres is required to solidify this result, however. We contextualize our results with those from other semi-analytic models and hydrodynamic simulations.

Experimental test of plant canopy reflectance models on cotton

NASA Technical Reports Server (NTRS)

Lemaster, E. W.

1973-01-01

Spectroradiometric data on the bidirectional reflectance function was collected for a cotton canopy as a function of observer zenith angle, observer angle, and solar zenith angle. The area under study was about 40 miles from the Gulf of Mexico and the prevailing winds blew inland such that cloud formation increased during the day. The standard reflectance panel was constructed of plywood that had been spray painted with a flat white latex paint. Physical and optical plant parameters were measured. A time lapse mechanism was constructed to operate a 16 mm movie camera such that single frames could be exposed at intervals of one per second up to one per hour. Data were digitized from a strip chart recorder and reflectance panel measurements.

Optimization design of LED heat dissipation structure based on strip fins

NASA Astrophysics Data System (ADS)

Xue, Lingyun; Wan, Wenbin; Chen, Qingguang; Rao, Huanle; Xu, Ping

2018-03-01

To solve the heat dissipation problem of LED, a radiator structure based on strip fins is designed and the method to optimize the structure parameters of strip fins is proposed in this paper. The combination of RBF neural networks and particle swarm optimization (PSO) algorithm is used for modeling and optimization respectively. During the experiment, the 150 datasets of LED junction temperature when structure parameters of number of strip fins, length, width and height of the fins have different values are obtained by ANSYS software. Then RBF neural network is applied to build the non-linear regression model and the parameters optimization of structure based on particle swarm optimization algorithm is performed with this model. The experimental results show that the lowest LED junction temperature reaches 43.88 degrees when the number of hidden layer nodes in RBF neural network is 10, the two learning factors in particle swarm optimization algorithm are 0.5, 0.5 respectively, the inertia factor is 1 and the maximum number of iterations is 100, and now the number of fins is 64, the distribution structure is 8*8, and the length, width and height of fins are 4.3mm, 4.48mm and 55.3mm respectively. To compare the modeling and optimization results, LED junction temperature at the optimized structure parameters was simulated and the result is 43.592°C which approximately equals to the optimal result. Compared with the ordinary plate-fin-type radiator structure whose temperature is 56.38°C, the structure greatly enhances heat dissipation performance of the structure.

Analysis of a parallelized nonlinear elliptic boundary value problem solver with application to reacting flows

NASA Technical Reports Server (NTRS)

Keyes, David E.; Smooke, Mitchell D.

1987-01-01

A parallelized finite difference code based on the Newton method for systems of nonlinear elliptic boundary value problems in two dimensions is analyzed in terms of computational complexity and parallel efficiency. An approximate cost function depending on 15 dimensionless parameters is derived for algorithms based on stripwise and boxwise decompositions of the domain and a one-to-one assignment of the strip or box subdomains to processors. The sensitivity of the cost functions to the parameters is explored in regions of parameter space corresponding to model small-order systems with inexpensive function evaluations and also a coupled system of nineteen equations with very expensive function evaluations. The algorithm was implemented on the Intel Hypercube, and some experimental results for the model problems with stripwise decompositions are presented and compared with the theory. In the context of computational combustion problems, multiprocessors of either message-passing or shared-memory type may be employed with stripwise decompositions to realize speedup of O(n), where n is mesh resolution in one direction, for reasonable n.

GASP: Gas stripping and the outskirts of galaxies as a function of environment

NASA Astrophysics Data System (ADS)

Poggianti, Bianca; GASP Team

2017-03-01

We present GASP, an ongoing ESO Large Program with MUSE aiming to study gas removal processes from galaxies at low redshift. GASP targets 100 galaxies with tails, tentacles and one-sided debris. MUSE data allows a detailed investigation of the ionized stripped gas, as well as of the gas and stars within the galaxy out to large distances from the galaxy center. We show the first results for two of the GASP galaxies that are striking cluster jellyfish galaxies of stellar masses ~ 1011 M ⊙.

Utility of the urine reagent strip leucocyte esterase assay for the diagnosis of meningitis in resource-limited settings: meta-analysis

PubMed Central

Bortcosh, William; Siedner, Mark; Carroll, Ryan W.

2018-01-01

OBJECTIVE Diagnosis of bacterial meningitis often requires cytometry, chemistry and/or microbiologic culture capabilities. Unfortunately, laboratory resources in low-resource settings (LRS) often lack the capacity to perform these studies. We sought to determine whether the presence of white blood cells in CSF detected by commercially available urine reagent strips could aid in the diagnosis of bacterial meningitis. METHODS We searched PubMed for studies published between 1980 and 2016 that investigated the use of urine reagent strips to identify cerebrospinal fluid (CSF) pleocytosis. We assessed studies in any language that enrolled subjects who underwent lumbar puncture and had cerebrospinal fluid testing by both standard laboratory assays and urine reagent strips. We abstracted true-positive, false-negative, false-positive and true-negative counts for each study using a diagnostic threshold of ≥10 white blood cells per microlitre for suspected bacterial meningitis and performed mixed regression modelling with random effects to estimate pooled diagnostic accuracy across studies. RESULTS Our search returned 13 studies including 2235 participants. Urine reagent strips detected CSF pleocytosis with a pooled sensitivity of 92% (95% CI: 84–96), a pooled specificity of 98% (95% CI: 94–99) and a negative predictive value of 99% when the bacterial meningitis prevalence is 10%. CONCLUSIONS Urine reagent strips could provide a rapid and accurate tool to detect CSF pleocytosis, which, if negative, can be used to exclude diagnosis of bacterial meningitis in settings without laboratory infrastructure. Further investigation of the diagnostic value of using protein, glucose and bacteria components of these strips is warranted. PMID:28627004

The effective temperature of the white-dwarf star and ZZ Ceti candidate Wolf 485A

NASA Technical Reports Server (NTRS)

Digel, S. W.; Shipman, H. L.

1984-01-01

Previous multichannel observations of W485A (WD 1327-08) have placed it in the instability strip, the effective temperature range 11,000-13,000 K. In the instability strip, most of the stars (the ZZ Ceti stars) are variable, but W485A has not been detected to be variable. In this paper, high-resolution spectra of W485A and improved hydrogen-line broadening routines are used in the ATLAS model-atmospheres program to find the temperature of W485A; the estimate of effective temperature most consistent with the other data on the star is 14,600 K, outside the instability strip.

GASP. IX. Jellyfish galaxies in phase-space: an orbital study of intense ram-pressure stripping in clusters

NASA Astrophysics Data System (ADS)

Jaffé, Yara L.; Poggianti, Bianca M.; Moretti, Alessia; Gullieuszik, Marco; Smith, Rory; Vulcani, Benedetta; Fasano, Giovanni; Fritz, Jacopo; Tonnesen, Stephanie; Bettoni, Daniela; Hau, George; Biviano, Andrea; Bellhouse, Callum; McGee, Sean

2018-06-01

It is well known that galaxies falling into clusters can experience gas stripping due to ram pressure by the intra-cluster medium. The most spectacular examples are galaxies with extended tails of optically bright stripped material known as `jellyfish'. We use the first large homogeneous compilation of jellyfish galaxies in clusters from the WINGS and OmegaWINGS surveys, and follow-up MUSE observations from the GASP MUSE programme to investigate the orbital histories of jellyfish galaxies in clusters and reconstruct their stripping history through position versus velocity phase-space diagrams. We construct analytic models to define the regions in phase-space where ram-pressure stripping is at play. We then study the distribution of cluster galaxies in phase-space and find that jellyfish galaxies have on average higher peculiar velocities (and higher cluster velocity dispersion) than the overall population of cluster galaxies at all cluster-centric radii, which is indicative of recent infall into the cluster and radial orbits. In particular, the jellyfish galaxies with the longest gas tails reside very near the cluster cores (in projection) and are moving at very high speeds, which coincides with the conditions of the most intense ram pressure. We conclude that many of the jellyfish galaxies seen in clusters likely formed via fast (˜1-2 Gyr), incremental, outside-in ram-pressure stripping during first infall into the cluster in highly radial orbits.

High Pressure Water Stripping Using Multi-Orifice Nozzles

NASA Technical Reports Server (NTRS)

Hoppe, David

1999-01-01

The use of multi-orifice rotary nozzles greatly increases the speed and stripping effectiveness of high pressure water blasting systems, but also greatly increases the complexity of selecting and optimizing the operating parameters. The rotational speed of the nozzle must be coupled with its transverse velocity as it passes across the surface of the substrate being stripped. The radial and angular positions of each orifice must be included in the analysis of the nozzle configuration. Orifices at the outer edge of the nozzle head move at a faster rate than the orifices located near the center. The energy transmitted to the surface from the impact force of the water stream from an outer orifice is therefore spread over a larger area than energy from an inner orifice. Utilizing a larger diameter orifice in the outer radial positions increases the total energy transmitted from the outer orifice to compensate for the wider distribution of energy. The total flow rate from the combination of all orifices must be monitored and should be kept below the pump capacity while choosing orifice to insert in each position. The energy distribution from the orifice pattern is further complicated since the rotary path of all the orifices in the nozzle head pass through the center section. All orifices contribute to the stripping in the center of the path while only the outer most orifice contributes to the stripping at the edge of the nozzle. Additional orifices contribute to the stripping from the outer edge toward the center section. With all these parameters to configure and each parameter change affecting the others, a computer model was developed to track and coordinate these parameters. The computer simulation graphically indicates the cumulative affect from each parameter selected. The result from the proper choices in parameters is a well designed, highly efficient stripping system. A poorly chosen set of parameters will cause the nozzle to strip aggressively in some areas while leaving the coating untouched in adjacent sections. The high pressure water stripping system can be set to extremely aggressive conditions allowing stripping of hard to remove adhesives, paint systems, and even cladding and chromate conversion coatings. The energy force can also be reduced to strip coatings from thin aluminum substrates without causing any damage or deterioration to the substrate's surface. High pressure water stripping of aerospace components has thus proven to be an efficient and cost effective method for cleaning and removing coatings.

High Pressure Water Stripping Using Multi-Orifice Nozzles

NASA Technical Reports Server (NTRS)

Hoppe, David T.

1998-01-01

The use of multi-orifice rotary nozzles not only increases the speed and stripping effectiveness of high pressure water blasting systems, but also greatly increases the complexity of selecting and optimizing the operating parameters. The rotational speed of the nozzle must be coupled with the transverse velocity of the nozzle as it passes across the surface of the substrate being stripped. The radial and angular positions of each orifice must be included in the analysis of the nozzle configuration. Since orifices at the outer edge of the nozzle head move at a faster rate than the orifice located near the center, the energy impact force of the water stream from the outer orifice is spread over a larger area than the water streams from the inner orifice. Utilizing a larger diameter orifice in the outer radial positions increases the energy impact to compensate for its wider force distribution. The total flow rate from the combination of orifices must be monitored and kept below the pump capacity while choosing an orifice to insert in each position. The energy distribution from the orifice pattern is further complicated since the rotary path of all orifices in the nozzle head pass through the center section, contributing to the stripping in this area while only the outer most orifice contributes to the stripping in the shell area at the extreme outside edge of the nozzle. From t he outer most shell to the center section, more orifices contribute to the stripping in each progressively reduced diameter shell. With all these parameters to configure and each parameter change affecting the others, a computer model was developed to track and coordinate these parameters. The computer simulation responds by graphically indicating the cumulative affect from each parameter selected. The results from the proper choices in parameters is a well designed, highly efficient stripping system. A poorly chosen set of parameters will cause the nozzle to strip aggressively in some areas while leaving the coating untouched in adjacent sections. The high pressure water stripping system can be set to extremely aggressive conditions allowing stripping of hard to remove adhesives, paint systems, cladding and chromate conversion coatings. The energy force can be reduced to strip coatings from thin aluminum substrates without causing damage or deterioration to the substrate's surface. High pressure water stripping of aerospace components have thus proven to be an efficient and cost effective method for cleaning and removing coatings.

Chitosan-Sodium Phytate Films with a Strong Water Barrier and Antimicrobial Properties Produced via One-Step-Consecutive-Stripping and Layer-by-Layer-Casting Technologies.

PubMed

Yang, Jie; Xiong, Liu; Li, Man; Sun, Qingjie

2018-06-20

The pursuit of sustainable functional materials requires the development of materials based on renewable resources and efficient fabrication methods. Here, we first fabricated chitosan-sodium phytate films via one-step-stripping and layer-by-layer-casting technologies. The proposed film-fabrication methods are general, facile, environmentally benign, cost-effective, and easy to scale up. The resultant one-step-stripped film was thin (9 ± 1 μm), soft, transparent, and strong, whereas the thickness of the layer-by-layer-cast film was 70 ± 3 μm. FTIR analysis of the films indicated the formation of interactions between the phosphoric groups in sodium phytate and the amino groups in chitosan. More importantly, the water-vapor-permeability values of the one-step-stripped and cast films were 4-5 orders of magnitude lower than chitosan films reported before. Layer-by-layer-cast films in particular exhibited high tensile strength (49.21 ± 1.12 MPa) and were more than three times stronger than other polyelectrolyte multilayer films. Both types of films remained stable in an acidic environment. Furthermore, the layer-by-layer-assembled films presented greater antimicrobial activity than the stripped films. The developed chitosan-sodium phytate films can enhance several biomedical and environmental applications, such as packaging, drug delivery, diagnostics, microfluidics, and biosensing.

Reconstruction of stratum corneum profile of porcine ear skin after tape stripping using UV/VIS spectroscopy

NASA Astrophysics Data System (ADS)

Popov, Alexey P.; Lademann, Jürgen; Priezzhev, Alexander V.; Myllylä, Risto

2007-07-01

Stratum corneum (horny layer) is a superficial skin layer consisting of dead cells. To reveal in-depth penetration profiles of substances topically applied onto skin surface, a minimally invasive method called tape stripping is widely used. It introduces consecutive removal of micrometer-thick cell layers of stratum corneum from the same treated skin area using an adhesive tape. Prerequisite to the substance penetration profile is the reconstruction of the removed stratum corneum by analyzing the amount of corneocytes (cells of stratum corneum from) stuck to each tape strip. Before application in vivo on humans, porcine skin is often used for such kind of studies. In this paper, we present results of the experiments with porcine skin in vitro (ears of freshly slaughtered pigs) and compare them with those carried out on humans in vivo (flexor forearm) taken from references. As we proved experimentally, there is a linear dependence between the absorbance (equals to logarithm of inverse transmittance) and thickness of the corneocytes on tape strips for all wavelength of the investigated region (300-1050 nm). Dependence of the cumulative absorbance of removed stratum corneum on tape strip number can be satisfactory fitted by an exponential function. This relationship allows evaluation of the relative share of the removed stratum corneum without complete removal of the layer. All the obtained results correlate well with those obtained on humans.

Dominant root locus in state estimator design for material flow processes: A case study of hot strip rolling.

PubMed

Fišer, Jaromír; Zítek, Pavel; Skopec, Pavel; Knobloch, Jan; Vyhlídal, Tomáš

2017-05-01

The purpose of the paper is to achieve a constrained estimation of process state variables using the anisochronic state observer tuned by the dominant root locus technique. The anisochronic state observer is based on the state-space time delay model of the process. Moreover the process model is identified not only as delayed but also as non-linear. This model is developed to describe a material flow process. The root locus technique combined with the magnitude optimum method is utilized to investigate the estimation process. Resulting dominant roots location serves as a measure of estimation process performance. The higher the dominant (natural) frequency in the leftmost position of the complex plane the more enhanced performance with good robustness is achieved. Also the model based observer control methodology for material flow processes is provided by means of the separation principle. For demonstration purposes, the computer-based anisochronic state observer is applied to the strip temperatures estimation in the hot strip finishing mill composed of seven stands. This application was the original motivation to the presented research. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Influence of field penetration ratios and filamentation on end-effect related hysteretic loss reductions for superconducting strips

NASA Astrophysics Data System (ADS)

Dong, K.; Sumption, M.; Collings, E. W.; Majoros, M.; Yu, H.; Hu, M.

2017-12-01

There are a few key conductor-specific factors which influence the power loss of superconductors; these include critical current, geometry, and normal metal resistivity. This paper focuses on the influence of sample geometry on the power loss of superconducting strips and the effect of filamentation and sample length as a function of the field penetration state of the superconductor. We start with the analytical equations for infinite slabs and strips and then consider the influence of end effects for both unstriated and striated conductor. The loss is then calculated and compared as a function of applied field for striated and unstriated conductors. These results are much more general than they might seem at first glance, since they will be important building blocks for analytic loss calculations for twisted geometries for coated conductors, including helical (Conductor on Round Core, CORC), and twisted (e.g., twist stack cables) geometries. We show that for relatively low field penetration, end effects and reduced field penetration both reduce loss. In addition, for filamentary samples the relevant ratio of length scales becomes the filament width to sample length, thus modifying the loss ratios.

Magnetoelastic Effect-Based Transmissive Stress Detection for Steel Strips: Theory and Experiment

PubMed Central

Zhang, Qingdong; Su, Yuanxiao; Zhang, Liyuan; Bi, Jia; Luo, Jiang

2016-01-01

For the deficiencies of traditional stress detection methods for steel strips in industrial production, this paper proposes a non-contact stress detection scheme based on the magnetoelastic effect. The theoretical model of the transmission-type stress detection is established, in which the output voltage and the tested stress obey a linear relation. Then, a stress detection device is built for the experiment, and Q235 steel under uniaxial tension is tested as an example. The result shows that the output voltage rises linearly with the increase of the tensile stress, consistent with the theoretical prediction. To ensure the accuracy of the stress detection method in actual application, the temperature compensation, magnetic shielding and some other key technologies are investigated to reduce the interference of the external factors, such as environment temperature and surrounding magnetic field. The present research develops the theoretical and experimental foundations for the magnetic stress detection system, which can be used for online non-contact monitoring of strip flatness-related stress (tension distribution or longitudinal residual stress) in the steel strip rolling process, the quality evaluation of strip flatness after rolling, the life and safety assessment of metal construction and other industrial production links. PMID:27589742

Thermally assisted peeling of an elastic strip in adhesion with a substrate via molecular bonds

NASA Astrophysics Data System (ADS)

Qian, Jin; Lin, Ji; Xu, Guang-Kui; Lin, Yuan; Gao, Huajian

A statistical model is proposed to describe the peeling of an elastic strip in adhesion with a flat substrate via an array of non-covalent molecular bonds. Under an imposed tensile peeling force, the interfacial bonds undergo diffusion-type transition in their bonding state, a process governed by a set of probabilistic equations coupled to the stretching, bending and shearing of the elastic strip. Because of the low characteristic energy scale associated with molecular bonding, thermal excitations are found to play an important role in assisting the escape of individual molecular bonds from their bonding energy well, leading to propagation of the peeling front well below the threshold peel-off force predicted by the classical theories. Our study establishes a link between the deformation of the strip and the spatiotemporal evolution of interfacial bonds, and delineates how factors like the peeling force, bending rigidity of the strip and binding energy of bonds influence the resultant peeling velocity and dimensions of the process zone. In terms of the apparent adhesion strength and dissipated energy, the bond-mediated interface is found to resist peeling in a strongly rate-dependent manner.

A spiking network model of cerebellar Purkinje cells and molecular layer interneurons exhibiting irregular firing

PubMed Central

Lennon, William; Hecht-Nielsen, Robert; Yamazaki, Tadashi

2014-01-01

While the anatomy of the cerebellar microcircuit is well-studied, how it implements cerebellar function is not understood. A number of models have been proposed to describe this mechanism but few emphasize the role of the vast network Purkinje cells (PKJs) form with the molecular layer interneurons (MLIs)—the stellate and basket cells. We propose a model of the MLI-PKJ network composed of simple spiking neurons incorporating the major anatomical and physiological features. In computer simulations, the model reproduces the irregular firing patterns observed in PKJs and MLIs in vitro and a shift toward faster, more regular firing patterns when inhibitory synaptic currents are blocked. In the model, the time between PKJ spikes is shown to be proportional to the amount of feedforward inhibition from an MLI on average. The two key elements of the model are: (1) spontaneously active PKJs and MLIs due to an endogenous depolarizing current, and (2) adherence to known anatomical connectivity along a parasagittal strip of cerebellar cortex. We propose this model to extend previous spiking network models of the cerebellum and for further computational investigation into the role of irregular firing and MLIs in cerebellar learning and function. PMID:25520646

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

Ding, Huanjun; Cho, Hyo-Min; Molloi, Sabee, E-mail: symolloi@uci.edu

Purpose: To investigate the feasibility of characterizing a Si strip photon-counting detector using x-ray fluorescence. Methods: X-ray fluorescence was generated by using a pencil beam from a tungsten anode x-ray tube with 2 mm Al filtration. Spectra were acquired at 90° from the primary beam direction with an energy-resolved photon-counting detector based on an edge illuminated Si strip detector. The distances from the source to target and the target to detector were approximately 19 and 11 cm, respectively. Four different materials, containing silver (Ag), iodine (I), barium (Ba), and gadolinium (Gd), were placed in small plastic containers with a diametermore » of approximately 0.7 cm for x-ray fluorescence measurements. Linear regression analysis was performed to derive the gain and offset values for the correlation between the measured fluorescence peak center and the known fluorescence energies. The energy resolutions and charge-sharing fractions were also obtained from analytical fittings of the recorded fluorescence spectra. An analytical model, which employed four parameters that can be determined from the fluorescence calibration, was used to estimate the detector response function. Results: Strong fluorescence signals of all four target materials were recorded with the investigated geometry for the Si strip detector. The average gain and offset of all pixels for detector energy calibration were determined to be 6.95 mV/keV and −66.33 mV, respectively. The detector’s energy resolution remained at approximately 2.7 keV for low energies, and increased slightly at 45 keV. The average charge-sharing fraction was estimated to be 36% within the investigated energy range of 20–45 keV. The simulated detector output based on the proposed response function agreed well with the experimental measurement. Conclusions: The performance of a spectral imaging system using energy-resolved photon-counting detectors is very dependent on the energy calibration of the detector. The proposed x-ray fluorescence technique offers an accurate and efficient way to calibrate the energy response of a photon-counting detector.« less

Elevated rates of force development and MgATP binding in F764L and S532P myosin mutations causing dilated cardiomyopathy.

PubMed

Palmer, Bradley M; Schmitt, Joachim P; Seidman, Christine E; Seidman, J G; Wang, Yuan; Bell, Stephen P; Lewinter, Martin M; Maughan, David W

2013-04-01

Dilated cardiomyopathy (DCM) is a disease characterized by dilation of the ventricular chambers and reduced contractile function. We examined the contractile performance of chemically-skinned ventricular strips from two heterozygous murine models of DCM-causing missense mutations of myosin, F764L/+ and S532P/+, in an α-myosin heavy chain (MyHC) background. In Ca(2+)-activated skinned myocardial strips, the maximum developed tension in F764L/+ was only ~50% that of litter-mate controls (+/+). The F764L/+ also exhibited significantly reduced rigor stiffness, loaded shortening velocity and power output. Corresponding indices for S532P/+ strips were not different from controls. Manipulation of MgATP concentration in conjunction with measures of viscoelasticity, which provides estimates of myosin detachment rate 2πc, allowed us to probe the molecular basis of changes in crossbridge kinetics that occur with the myosin mutations. By examining the response of detachment rate to varying MgATP we found the rate of MgADP release was unaffected by the myosin mutations. However, MgATP binding rate was higher in the DCM groups compared to controls (422±109mM(-1)·s(-1) in F764L/+, 483±74mM(-1)·s(-1) in S532P/+ and 303±18mM(-1)·s(-1) in +/+). In addition, the rate constant of force development, 2πb, was significantly higher in DCM groups compared to controls (at 5mM MgATP: 36.9±4.9s(-1) in F764L/+, 32.9±4.5s(-1) in S532P/+ and 18.2±1.7s(-1) in +/+). These results suggest that elevated rates of force development and MgATP binding are features of cardiac myofilament function that underlie the development of DCM. Copyright © 2013 Elsevier Ltd. All rights reserved.

Static and dynamic stress heterogeneity in a multiscale model of the asthmatic airway wall

PubMed Central

Hiorns, J. E.

2016-01-01

Airway hyperresponsiveness (AHR) is a key characteristic of asthma that remains poorly understood. Tidal breathing and deep inspiration ordinarily cause rapid relaxation of airway smooth muscle (ASM) (as demonstrated via application of length fluctuations to tissue strips) and are therefore implicated in modulation of AHR, but in some cases (such as application of transmural pressure oscillations to isolated intact airways) this mechanism fails. Here we use a multiscale biomechanical model for intact airways that incorporates strain stiffening due to collagen recruitment and dynamic force generation by ASM cells to show that the geometry of the airway, together with interplay between dynamic active and passive forces, gives rise to large stress and compliance heterogeneities across the airway wall that are absent in tissue strips. We show further that these stress heterogeneities result in auxotonic loading conditions that are currently not replicated in tissue-strip experiments; stresses in the strip are similar to hoop stress only at the outer airway wall and are under- or overestimates of stresses at the lumen. Taken together these results suggest that a previously underappreciated factor, stress heterogeneities within the airway wall and consequent ASM cellular response to this micromechanical environment, could contribute to AHR and should be explored further both theoretically and experimentally. PMID:27197860

NiTi Alloy Negator Springs for Long-Stroke Constant-Force Shape Memory Actuators: Modeling, Simulation and Testing

NASA Astrophysics Data System (ADS)

Spaggiari, Andrea; Dragoni, Eugenio; Tuissi, Ausonio

2014-07-01

This work aims at the experimental characterization and modeling validation of shape memory alloy (SMA) Negator springs. According to the classic engineering books on springs, a Negator spring is a spiral spring made of strip of metal wound on the flat with an inherent curvature such that, in repose, each coil wraps tightly on its inner neighbor. The main feature of a Negator springs is the nearly constant force displacement behavior in the unwinding of the strip. Moreover the stroke is very long, theoretically infinite, as it depends only on the length of the initial strip. A Negator spring made in SMA is built and experimentally tested to demonstrate the feasibility of this actuator. The shape memory Negator spring behavior can be modeled with an analytical procedure, which is in good agreement with the experimental test and can be used for design purposes. In both cases, the material is modeled as elastic in austenitic range, while an exponential continuum law is used to describe the martensitic behavior. The experimental results confirms the applicability of this kind of geometry to the shape memory alloy actuators, and the analytical model is confirmed to be a powerful design tool to dimension and predict the spring behavior both in martensitic and austenitic range.

Modeling CO{sub 2} and H{sub 2}S solubility in MDEA and DEA: Design implications

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

Rochelle, G.T.; Posey, M.

1996-12-31

The solubility of H{sub 2}S and CO{sub 2} in aqueous alkanolamines affects solution capacity and the required circulation rate for acid gas absorption. These thermodynamics also determine the relationship of steam rate and the lean loading of the solution which in turn sets the leak of acid gas from the top of the absorber. Finally, the mechanisms of mass transfer and the role of kinetics, especially in stripping, depend on the vapor/liquid equilibria. Published measurements of CO{sub 2} and H{sub 2}S solubility in methyldiethanolamine (MDEA) and diethanolamine (DEA) are not in general agreement, especially at low loading of acid gas.more » The available sets of solubility data have been regressed with the AspenPlus electrolyte/NRTL model. All of the parameters and constants that make up this model have been carefully evaluated. Independent thermodynamic data such as freezing point and heat of mixing have been included in the regression to strengthen the estimates of model parameters. The parameters for each set of solubility data have been evaluated in an attempt to determine which set is correct. Each evaluated model has been used to calculate the acid gas capacity and minimum stripping steam rate for several industrial cases of acid gas absorption/stripping.« less

Sustainable in-well vapor stripping: A design, analytical model, and pilot study for groundwater remediation.

PubMed

Sutton, Patrick T; Ginn, Timothy R

2014-12-15

A sustainable in-well vapor stripping system is designed as a cost-effective alternative for remediation of shallow chlorinated solvent groundwater plumes. A solar-powered air compressor is used to inject air bubbles into a monitoring well to strip volatile organic compounds from a liquid to vapor phase while simultaneously inducing groundwater circulation around the well screen. An analytical model of the remediation process is developed to estimate contaminant mass flow and removal rates. The model was calibrated based on a one-day pilot study conducted in an existing monitoring well at a former dry cleaning site. According to the model, induced groundwater circulation at the study site increased the contaminant mass flow rate into the well by approximately two orders of magnitude relative to ambient conditions. Modeled estimates for 5h of pulsed air injection per day at the pilot study site indicated that the average effluent concentrations of dissolved tetrachloroethylene and trichloroethylene can be reduced by over 90% relative to the ambient concentrations. The results indicate that the system could be used cost-effectively as either a single- or multi-well point technology to substantially reduce the mass of dissolved chlorinated solvents in groundwater. Copyright © 2014 Elsevier B.V. All rights reserved.

Antibody-directed myostatin inhibition improves diaphragm pathology in young but not adult dystrophic mdx mice.

PubMed

Murphy, Kate T; Ryall, James G; Snell, Sarah M; Nair, Lawrence; Koopman, René; Krasney, Philip A; Ibebunjo, Chikwendu; Holden, Kathryn S; Loria, Paula M; Salatto, Christopher T; Lynch, Gordon S

2010-05-01

Duchenne muscular dystrophy (DMD) is characterized by progressive skeletal muscle wasting and weakness, leading to premature death from respiratory and/or cardiac failure. A clinically relevant question is whether myostatin inhibition can improve function of the diaphragm, which exhibits a severe and progressive pathology comparable with that in DMD. We hypothesized that antibody-directed myostatin inhibition would improve the pathophysiology of diaphragm muscle strips from young mdx mice (when the pathology is mild) and adult mdx mice (when the pathology is quite marked). Five weeks treatment with a mouse chimera of anti-human myostatin antibody (PF-354, 10 mg/kg/week) increased muscle mass (P < 0.05) and increased diaphragm median fiber cross-sectional area (CSA, P < 0.05) in young C57BL/10 and mdx mice, compared with saline-treated controls. PF-354 had no effect on specific force (sPo, maximum force normalized to muscle CSA) of diaphragm muscle strips from young C57BL/10 mice, but increased sPo by 84% (P < 0.05) in young mdx mice. In contrast, 8 weeks of PF-354 treatment did not improve muscle mass, median fiber CSA, collagen infiltration, or sPo of diaphragm muscle strips from adult mdx mice. PF-354 antibody-directed myostatin inhibition completely restored the functional capacity of diaphragm strips to control levels when treatment was initiated early, but not in the later stages of disease progression, suggesting that such therapies may only have a limited window of efficacy for DMD and related conditions.

HI-Selected Galaxies in Hierarchical Models of Galaxy Formation and Evolution

NASA Astrophysics Data System (ADS)

Zoldan, Anna

2017-07-01

This poster presents the main results of a statistical study of HI-selected galaxies based on six different semi-analytic models, all run on the same cosmological N-body simulation. One of these models includes an explicit treatment for the partition of cold gas into atomic and molecular hydrogen. All models considered agree nicely with the measured HI mass function in the local Universe and with the measured scaling relations between HI and galaxy stellar mass. Most models also reproduce the observed 2-point correlation function for HI rich galaxies, with the exception of one model that predicts very little HI associated with galaxies in haloes above 10^12 Msun. We investigated the influence of satellite treatment on the final HI content and found that it introduces large uncertainties at low HI masses. We found that the assumption of instantaneous stripping of hot gas in satellites does not translate necessarily in lower HI masses. We demonstrate that the assumed stellar feedback, combined with star formation, also affect significantly the gas content of satellite galaxies. Finally, we also analyse the origin of the correlation between HI content of model galaxies and the spin of the parent haloes. Zoldan et al., 2016, MNRAS, 465, 2236

Detailed non-LTE calculations of the iron emission from NGC 1068

NASA Technical Reports Server (NTRS)

Band, David L.; Klein, Richard I.; Castor, John I.; Nash, J. K.

1989-01-01

The X-ray iron line emission from NGC 1068 observed by the Ginga satellite is modeled using the new multiline, multilevel, non-LTE radiative transport code ALTAIR and a detailed atomic model for Ne-like through stripped iron. The parameter space of the obscured type 1 Seyfert nucleus model for this object is studied. The equivalent width is greater than previously predicted. It is found that detailed radiative transfer can have a significant effect on the observed line flux both for the K alpha line and for the L-shell emission. The ionization of the iron increases with temperature. Therefore the K alpha equivalent width and energy is a function not only of the ionization parameter, but also of the column depth and temperature. For a likely model of NGC 1068 it is found that the iron abundance is about twice solar, but that modifications of this model may permit a smaller abundance.

A model of galactic cosmic rays for use in calculating linear energy transfer spectra

NASA Technical Reports Server (NTRS)

Chen, J.; Chenette, D.; Clark, R.; Garcia-Munoz, M.; Guzik, T. G.; Pyle, K. R.; Sang, Y.; Wefel, J. P.

1994-01-01

The Galactic Cosmic Rays (GCR) contain fully stripped nuclei, from Hydrogen to beyond the Iron group, accelerated to high energies and are a major component of the background radiation encountered by satellites and interplanetary spacecraft. This paper presents a GCR model which is based upon our current understanding of the astrophysics of GCR transport through interstellar and interplanetary space. The model can be used to predict the energy spectra for all stable and long-lived radioactive species from H to Ni over an energy range from 50 to 50,000 MeV/nucleon as a function of a single parameter, the solar modulation level phi. The details of this model are summarized, phi is derived for the period 1974 to present, and results from this model during the 1990/1991 Combined Release and Radiation Effects Satellite (CRRES) mission are presented.

Numerical and experimental study on multi-pass laser bending of AH36 steel strips

NASA Astrophysics Data System (ADS)

Fetene, Besufekad N.; Kumar, Vikash; Dixit, Uday S.; Echempati, Raghu

2018-02-01

Laser bending is a process of bending of plates, small sized sheets, strips and tubes, in which a moving or stationary laser beam heats the workpiece to achieve the desired curvature due to thermal stresses. Researchers studied the effects of different process parameters related to the laser source, material and workpiece geometry on laser bending of metal sheets. The studies are focused on large sized sheets. The workpiece geometry parameters like sheet thickness, length and width also affect the bend angle considerably. In this work, the effects of width and thickness on multi-pass laser bending of AH36 steel strips were studied experimentally and numerically. Finite element model using ABAQUS® was developed to investigate the size effect on the prediction of the bend angle. Microhardness and flexure tests showed an increase in the flexural strength as well as microhardness in the scanned zone. The microstructures of the bent strips also supported the physical observations.

Mechanistic simulation of batch acetone-butanol-ethanol (ABE) fermentation with in situ gas stripping using Aspen Plus™.

PubMed

Darkwah, Kwabena; Nokes, Sue E; Seay, Jeffrey R; Knutson, Barbara L

2018-05-22

Process simulations of batch fermentations with in situ product separation traditionally decouple these interdependent steps by simulating a separate "steady state" continuous fermentation and separation units. In this study, an integrated batch fermentation and separation process was simulated for a model system of acetone-butanol-ethanol (ABE) fermentation with in situ gas stripping, such that the fermentation kinetics are linked in real-time to the gas stripping process. A time-dependent cell growth, substrate utilization, and product production is translated to an Aspen Plus batch reactor. This approach capitalizes on the phase equilibria calculations of Aspen Plus to predict the effect of stripping on the ABE fermentation kinetics. The product profiles of the integrated fermentation and separation are shown to be sensitive to gas flow rate, unlike separate steady state fermentation and separation simulations. This study demonstrates the importance of coupled fermentation and separation simulation approaches for the systematic analyses of unsteady state processes.

Ram Pressure Stripping: Observations Meet Simulations

NASA Astrophysics Data System (ADS)

Past, Matthew; Ruszkowski, Mateusz; Sharon, Keren

2017-01-01

Ram pressure stripping occurs when a galaxy falls into the potential well of a cluster, removing gas and dust as the galaxy travels through the intracluster medium. This interaction leads to filamentary gas tails stretching behind the galaxy and plays an important role in galaxy evolution. Previously, these “jellyfish” galaxies had only been observed in nearby clusters, but recently, higher redshift (z > 0.3) examples have been found from HST data imaging.Recent work has shown that cosmic rays injected by supernovae can cause galactic disks to thicken due to cosmic ray pressure. We run three-dimensional magneto-hydrodynamical simulations of ram pressure stripping including cosmic rays to compare to previous models. We study how the efficiency of the ram pressure stripping of the gas, and the morphology of the filamentary tails, depend on the magnitude of the cosmic ray pressure support. We generate mock X-ray images and radio polarization data. Simultaneously, we perform an exhaustive search of the HST archive to increase the sample of jellyfish galaxies and compare selected cases to simulations.

Macro Pixel ASIC (MPA): the readout ASIC for the pixel-strip (PS) module of the CMS outer tracker at HL-LHC

NASA Astrophysics Data System (ADS)

Ceresa, D.; Marchioro, A.; Kloukinas, K.; Kaplon, J.; Bialas, W.; Re, V.; Traversi, G.; Gaioni, L.; Ratti, L.

2014-11-01

The CMS tracker at HL-LHC is required to provide prompt information on particles with high transverse momentum to the central Level 1 trigger. For this purpose, the innermost part of the outer tracker is based on a combination of a pixelated sensor with a short strip sensor, the so-called Pixel-Strip module (PS). The readout of these sensors is carried out by distinct ASICs, the Strip Sensor ASIC (SSA), for the strip layer, and the Macro Pixel ASIC (MPA) for the pixel layer. The processing of the data directly on the front-end module represents a design challenge due to the large data volume (30720 pixels and 1920 strips per module) and the limited power budget. This is the reason why several studies have been carried out to find the best compromise between ASICs performance and power consumption. This paper describes the current status of the MPA ASIC development where the logic for generating prompt information on particles with high transverse momentum is implemented. An overview of the readout method is presented with particular attention on the cluster reduction, position encoding and momentum discrimination logic. Concerning the architectural studies, a software test bench capable of reading physics Monte-Carlo generated events has been developed and used to validate the MPA design and to evaluate the MPA performance. The MPA-Light is scheduled to be submitted for fabrication this year and will include the full analog functions and a part of the digital logic of the final version in order to qualify the chosen VLSI technology for the analog front-end, the module assembly and the low voltage digital supply.

Test strips based on iron(iii)-impregnated alginate/polyacrylonitrile nanofibers for naked eye screening of tetracycline.

PubMed

Li, Yan; Mohammed, Abedalwafa; Li, De; Wang, Lu

2018-05-03

Tetracycline (TC) is an inexpensive broad-spectrum antibiotic used to treat infectious diseases and to promote growth in animals. However, driven by economic interest, abuse of TC poses a serious threat to human beings, and it remains a significant challenge to create easy-to-use TC colorimetric test strips for public use. Herein, we present a strategy to prepare free-standing, nanofibrous structured test strips with tortuous porous structure and large surface area by combining polyacrylonitrile nanofibrous membranes (PAN NMs), alginate, and Fe3+. In this approach, alginate was first functionalized on the PAN NMs and then, Fe3+ was assembled into the alginate to construct a TC-sensing surface. The resultant test strips exhibited the following integrated properties: fast sensing process (10 min), low naked eye detection limit (5 μg kg-1), excellent anti-interference ability, and satisfactory reusability. Furthermore, the TC concentration-dependent color change (yellow to maroon) was quantitatively visualized by an iPhone read-out hue parameter. All the findings indicate that this intriguing approach may pave the way for versatile designing of NMs to serve as a preventive treatment for the public.

The role of the urothelium and ATP in mediating detrusor smooth muscle contractility.

PubMed

Santoso, Aneira Gracia Hidayat; Sonarno, Ika Ariyani Bte; Arsad, Noor Aishah Bte; Liang, Willmann

2010-11-01

To examine the contractility of urothelium-intact (+UE) and urothelium-denuded (-UE) rat detrusor strips under adenosine triphosphate (ATP) treatment. Purinergic signaling exists in the bladder but both the inhibitory effect of ATP on detrusor contractions and the function of urothelial ATP are not established. Detrusor strips were obtained from bladders of young adult rats. Isometric tension from both transverse and longitudinal contractions was measured using a myograph. The muscarinic agonist carbachol (CCh) was used to induce contractions, which were under the influences of different concentrations of ATP. In both +UE and -UE strips, 1 mM ATP suppressed CCh-induced contractions. In longitudinal contractions, ATP added to the inhibitory effect of urothelium on CCh responses. Removal of the urothelium, but with exogenous ATP added, recovered the CCh responses to the same level as in +UE strips with no added ATP. Transverse contractions were less susceptible to ATP in the presence of urothelium. We showed that the urothelium and ATP suppressed CCh-induced contractions to a similar extent. The findings suggest an inhibitory role of urothelial ATP in mediating detrusor smooth muscle contractility, which may be impaired in diseased bladders. Copyright © 2010 Elsevier Inc. All rights reserved.

Folded Elastic Strip-Based Triboelectric Nanogenerator for Harvesting Human Motion Energy for Multiple Applications.

PubMed

Kang, Yue; Wang, Bo; Dai, Shuge; Liu, Guanlin; Pu, Yanping; Hu, Chenguo

2015-09-16

A folded elastic strip-based triboelectric nanogenerator (FS-TENG) made from two folded double-layer elastic strips of Al/PET and PTFE/PET can achieve multiple functions by low frequency mechanical motion. A single FS-TENG with strip width of 3 cm and length of 27 cm can generate a maximum output current, open-circuit voltage, and peak power of 55 μA, 840 V, and 7.33 mW at deformation frequency of 4 Hz with amplitude of 2.5 cm, respectively. This FS-TENG can work as a weight sensor due to its good elasticity. An integrated generator assembled by four FS-TENGs (IFS-TENG) can harvest the energy of human motion like flapping hands and walking steps. In addition, the IFS-TENG combined with electromagnetically induced electricity can achieve a completely self-driven doorbell with flashing lights. Moreover, a box-like generator integrated by four IFS-TENGs inside can work in horizontal or random motion modes and can be improved to harvest energy in all directions. This work promotes the research of completely self-driven systems and energy harvesting of human motion for applications in our daily life.

The VMC Survey - XXIV. Signatures of tidally stripped stellar populations from the inner Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Subramanian, Smitha; Rubele, Stefano; Sun, Ning-Chen; Girardi, Léo; de Grijs, Richard; van Loon, Jacco Th.; Cioni, Maria-Rosa L.; Piatti, Andrés E.; Bekki, Kenji; Emerson, Jim; Ivanov, Valentin D.; Kerber, Leandro; Marconi, Marcella; Ripepi, Vincenzo; Tatton, Benjamin L.

2017-05-01

We study the luminosity function of intermediate-age red clump stars using deep, near-infrared photometric data covering ˜20 deg2 located throughout the central part of the Small Magellanic Cloud (SMC), comprising the main body and the galaxy's eastern wing, based on observations obtained with the VISTA Survey of the Magellanic Clouds (VMC). We identified regions that show a foreground population (˜11.8 ± 2.0 kpc in front of the main body) in the form of a distance bimodality in the red clump distribution. The most likely explanation for the origin of this feature is tidal stripping from the SMC rather than the extended stellar haloes of the Magellanic Clouds and/or tidally stripped stars from the Large Magellanic Cloud. The homogeneous and continuous VMC data trace this feature in the direction of the Magellanic Bridge and, particularly, identify (for the first time) the inner region (˜2-2.5 kpc from the centre) from where the signatures of interactions start becoming evident. This result provides observational evidence of the formation of the Magellanic Bridge from tidally stripped material from the SMC.

A series of compact rejection filters based on the interaction between spoof SPPs and CSRRs.

PubMed

Zhang, Qian; Zhang, Hao Chi; Yin, Jia Yuan; Pan, Bai Cao; Cui, Tie Jun

2016-06-21

We propose a method to synthesize several band-rejection filters by etching split-ring resonators (SRRs) on the transmission line for spoof surface plasmon polaritons (SPPs), which is made of double-side or single-side corrugated metal strips. From dispersion relations, the corrugated strips can support spoof SPP modes when the operating frequency is less than the cutoff frequency. The electric field component perpendicular to the strip surface of the SPP modes can excite the complementary SRRs (CSRRs), leading to resonant modes preventing the SPP propagation near the resonant frequencies. Using this principle, single-frequency rejection filters, double-frequency rejection filters, and broad band-stop filters with bandwidth of 1.5 GHz have been designed and fabricated using the single- and/or double-side corrugated strips. Both measured results and numerical simulations demonstrate the excellent filtering characteristics of all design, which are in good agreements. The isolation of all filters can be less than -20 dB, and even reach to -38 dB at rejection frequencies. The proposed rejection and stop-band filters give important potentials to develop integrated plasmonic functional devices and circuits at microwave and terahertz frequencies.

Release kinetics of volatile organic compounds from roasted and ground coffee: online measurements by PTR-MS and mathematical modeling.

PubMed

Mateus, Maria-L; Lindinger, Christian; Gumy, Jean-C; Liardon, Remy

2007-12-12

The present work shows the possibilities and limitations in modeling release kinetics of volatile organic compounds (VOCs) from roasted and ground coffee by applying physical and empirical models such as the diffusion and Weibull models. The release kinetics of VOCs were measured online by proton transfer reaction-mass spectrometry (PTR-MS). Compounds were identified by GC-MS, and the contribution of the individual compounds to different mass fragments was elucidated by GC/PTR-MS. Coffee samples roasted to different roasting degrees and ground to different particle sizes were studied under dry and wet stripping conditions. To investigate the accuracy of modeling the VOC release kinetics recorded using PTR-MS, online kinetics were compared with kinetics reconstituted from purge and trap samplings. Results showed that uncertainties in ion intensities due to the presence of isobaric species may prevent the development of a robust mathematical model. Of the 20 identified compounds, 5 were affected to a lower extent as their contribution to specific m/z intensity varied by <15% over the stripping time. The kinetics of these compounds were fitted using physical and statistical models, respectively, the diffusion and Weibull models, which helped to identify the underlying release mechanisms. For dry stripping, the diffusion model allowed a good representation of the release kinetics, whereas for wet stripping conditions, release patterns were very complex and almost specific for each compound analyzed. In the case of prewetted coffee, varying particle size (approximately 400-1200 microm) had no significant effect on the VOC release rate, whereas for dry coffee, the release was faster for smaller particles. The absence of particle size effect in wet coffee was attributed to the increase of opened porosity and compound diffusivity by solubilization and matrix relaxation. To conclude, the accurate modeling of VOC release kinetics from coffee allowed small variations in compound release to be discriminated. Furthermore, it evidenced the different aroma compositions that may be obtained depending on the time when VOCs are recovered.

Experimental Water Droplet Impingement Data on Airfoils, Simulated Ice Shapes, an Engine Inlet and a Finite Wing

NASA Technical Reports Server (NTRS)

Papadakis, M.; Breer, M.; Craig, N.; Liu, X.

1994-01-01

An experimental method has been developed to determine the water droplet impingement characteristics on two- and three-dimensional aircraft surfaces. The experimental water droplet impingement data are used to validate particle trajectory analysis codes that are used in aircraft icing analyses and engine inlet particle separator analyses. The aircraft surface is covered with thin strips of blotter paper in areas of interest. The surface is then exposed to an airstream that contains a dyed-water spray cloud. The water droplet impingement data are extracted from the dyed blotter paper strips by measuring the optical reflectance of each strip with an automated reflectometer. Experimental impingement efficiency data represented for a NLF (1)-0414 airfoil, a swept MS (1)-0317 airfoil, a Boeing 737-300 engine inlet model, two simulated ice shapes and a swept NACA 0012 wingtip. Analytical impingement efficiency data are also presented for the NLF (1)-0414 airfoil and the Boeing 737-300 engine inlet model.

Coupled thermal-fluid-mechanics analysis of twin roll casting of A7075 aluminum alloy

NASA Astrophysics Data System (ADS)

Lee, Yun-Soo; Kim, Hyoung-Wook; Cho, Jae-Hyung; Chun, Se-Hwan

2017-09-01

Better understanding of temperature distribution and roll separation force during twin roll casting of aluminum alloys is critical to successfully fabricate good quality of aluminum strips. Therefore, the simulation techniques are widely applied to understand the twin roll casting process in a comprehensive way and to reduce the experimental time and cost of trial and error. However, most of the conventional approaches are considered thermally coupled flow, or thermally coupled mechanical behaviors. In this study, a fully coupled thermal-fluid-mechanical analysis of twin roll casting of A7075 aluminum strips was carried out using the finite element method. Temperature profile, liquid fraction and metal flow of aluminum strips with different thickness were predicted. Roll separation force and roll temperatures were experimentally obtained from a pilot-scale twin roll caster, and those results were compared with model predictions. Coupling the fluid of the liquid melt to the thermal and mechanical modeling reasonably predicted roll temperature distribution and roll separation force during twin roll casting.

Determination Of Slitting Criterion Parameter During The Multi Slit Rolling Process

NASA Astrophysics Data System (ADS)

Stefanik, Andrzej; Mróz, Sebastian; Szota, Piotr; Dyja, Henryk

2007-05-01

The rolling of rods with slitting of the strip calls for the use of special mathematical models that would allow for the separating of metal. A theoretical analysis of the effect of the gap of slitting rollers on the process of band slitting during the rolling of 20 mm and 16 mm-diameter ribbed rods rolled according to the two-strand technology was carried out within this study. For the numerical modeling of strip slitting the Forge3® computer program was applied. The strip slitting in the simulation is implemented by the algorithm of removing elements in which the critical value of the normalized Cockroft - Latham criterion has been exceeded. To determine the value of the criterion the inverse method was applied. Distance between a point, where crack begins, and point of contact metal with the slitting rollers was the parameter for analysis. Power and rolling torque during slit rolling were presented. Distribution and change of the stress in strand while slitting were presented.

Uneven-aged silviculture can enhance within stand heterogeneity and beetle diversity.

PubMed

Joelsson, Klara; Hjältén, Joakim; Work, Timothy

2018-01-01

Uneven-aged silviculture may better maintain species assemblages associated with old-growth forests than clear felling in part due to habitat heterogeneity created by maintaining standing retention strips adjacent to harvest trails. Retention strips and harvest trails created at the time of tree removal will likely have different microclimate and may harbor different assemblages. In some cases, the resultant stand heterogeneity associated with uneven-aged silviculture may be similar to natural small-scale disturbances. For beetles, increased light and temperature as well as potential access to young vegetation and deadwood substrates present in harvset trails may harbor beetle assemblages similar to those found in natural gaps. We sampled saproxylic beetles using flight intercept traps placed in harvest corridors and retention strips in 9 replicated uneven-aged spruce stands in central Sweden. We compared abundance, species richness and composition between harvest corridors and retention strips using generalized linear models, rarefaction, permutational multivariate analysis of variance and indicator species analysis. Canopy openness doubled, mean temperature and variability in daily temperature increased and humidity decreased on harvest trails. Beetle richness and abundance were greater in harvests trails than in retention strips and the beetle species composition differed significantly between habitats. Twenty-five species were associated with harvest trails, including three old-growth specialists such as Agathidium discoideum (Erichson), currently red-listed. We observed only one species, Xylechinus pilosus (Ratzeburg) that strongly favored retention strips. Harvest trails foster both open habitat species and old-growth species while retention strips harbored forest interior specialists. The combination of closed canopy, stratified forest in the retention strips and gap-like conditions on the harvest trails thus increases overall species richness and maintains more diverse assemblages at the stand level than would otherwise be seen in less heterogeneous stand types. This suggests that uneven-aged silviculture may provide added conservation benefits for both open habitat and old-growth specialists than silvicultural approaches that reduce stand heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Continuous-flow trapping and localized enrichment of micro- and nano-particles using induced-charge electrokinetics.

PubMed

Zhao, Cunlu; Yang, Chun

2018-02-14

In this work, we report an effective microfluidic technique for continuous-flow trapping and localized enrichment of micro- and nano-particles by using induced-charge electrokinetic (ICEK) phenomena. The proposed technique utilizes a simple microfluidic device that consists of a straight microchannel and a conducting strip attached to the bottom wall of the microchannel. Upon application of the electric field along the microchannel, the conducting strip becomes polarized to introduce two types of ICEK phenomena, the ICEK flow vortex and particle dielectrophoresis, and they are identified by a theoretical model formulated in this study to be jointly responsible for the trapping of particles over the edge of the conducting strip. Our experiments showed that successful trapping requires an AC/DC combined electric field: the DC component is mainly to induce electroosmotic flow for transporting particles to the trapping location; the AC component induces ICEK phenomena over the edge of the conducting strip for particle trapping. The performance of the technique is examined with respect to the applied electric voltage, AC frequency and the particle size. We observed that the trapped particles form a narrow band (nearly a straight line) defined by the edge of the conducting strip, thereby allowing localized particle enrichment. For instance, we found that under certain conditions a high particle enrichment ratio of 200 was achieved within 30 seconds. We also demonstrated that the proposed technique was able to trap particles from several microns down to several tens of nanometer. We believe that the proposed ICEK trapping would have great flexibility that the trapping location can be readily varied by controlling the location of the patterned conducting strip and multiple-location trapping can be expected with the use of multiple conducting strips.

Bayesian inference of galaxy formation from the K-band luminosity function of galaxies: tensions between theory and observation

NASA Astrophysics Data System (ADS)

Lu, Yu; Mo, H. J.; Katz, Neal; Weinberg, Martin D.

2012-04-01

We conduct Bayesian model inferences from the observed K-band luminosity function of galaxies in the local Universe, using the semi-analytic model (SAM) of galaxy formation introduced in Lu et al. The prior distributions for the 14 free parameters include a large range of possible models. We find that some of the free parameters, e.g. the characteristic scales for quenching star formation in both high-mass and low-mass haloes, are already tightly constrained by the single data set. The posterior distribution includes the model parameters adopted in other SAMs. By marginalizing over the posterior distribution, we make predictions that include the full inferential uncertainties for the colour-magnitude relation, the Tully-Fisher relation, the conditional stellar mass function of galaxies in haloes of different masses, the H I mass function, the redshift evolution of the stellar mass function of galaxies and the global star formation history. Using posterior predictive checking with the available observational results, we find that the model family (i) predicts a Tully-Fisher relation that is curved; (ii) significantly overpredicts the satellite fraction; (iii) vastly overpredicts the H I mass function; (iv) predicts high-z stellar mass functions that have too many low-mass galaxies and too few high-mass ones and (v) predicts a redshift evolution of the stellar mass density and the star formation history that are in moderate disagreement. These results suggest that some important processes are still missing in the current model family, and we discuss a number of possible solutions to solve the discrepancies, such as interactions between galaxies and dark matter haloes, tidal stripping, the bimodal accretion of gas, preheating and a redshift-dependent initial mass function.

Electric cartridge-type heater for producing a given non-uniform axial power distribution

DOEpatents

Clark, D.L.; Kress, T.S.

1975-10-14

An electric cartridge heater is provided to simulate a reactor fuel element for use in safety and thermal-hydraulic tests of model nuclear reactor systems. The electric heat-generating element of the cartridge heater consists of a specifically shaped strip of metal cut with variable width from a flat sheet of the element material. When spirally wrapped around a mandrel, the strip produces a coiled element of the desired length and diameter. The coiled element is particularly characterized by an electrical resistance that varies along its length due to variations in strip width. Thus, the cartridge heater is constructed such that it will produce a more realistic simulation of the actual nonuniform (approximately ''chopped'' cosine) power distribution of a reactor fuel element.

A test strip platform based on DNA-functionalized gold nanoparticles for on-site detection of mercury (II) ions.

PubMed

Guo, Zhiyong; Duan, Jing; Yang, Fei; Li, Min; Hao, Tingting; Wang, Sui; Wei, Danyi

2012-05-15

A test strip, based on DNA-functionalized gold nanoparticles for Hg(2+) detection, has been developed, optimized and validated. The developed colorimetric mercury sensor system exhibited a highly sensitive and selective response to mercury. The measurement principle is based on thymine-Hg(2+)-thymine (T-Hg(2+)-T) coordination chemistry and streptavidin-biotin interaction. A biotin-labeled and thiolated DNA was immobilized on the gold nanoparticles (AuNPs) surface through a self-assembling method. Another thymine-rich DNA, which was introduced to form DNA duplexes on the AuNPs surface with thymine-Hg(2+)-thymine (T-Hg(2+)-T) coordination in the presence of Hg(2+), was immobilized on the nitrocellulose membrane as the test zone. When Hg(2+) ions were introduced into this system, they induced the two strands of DNA to intertwist by forming T-Hg(2+)-T bonds resulting in a red line at the test zone. The biotin-labeled and thiolated DNA-functionalized AuNPs could be captured by streptavidin which was immobilized on the nitrocellulose membrane as the control zone. Under optimized conditions, the detection limit for Hg(2+) was 3 nM, which is lower than the 10nM, maximum contaminant limit defined by the US Environmental Protection Agency (EPA) for drinking water. A parallel analysis of Hg(2+) in pool water samples using cold vapor atomic absorption spectrometry showed comparable results to those obtained from the strip test. Therefore, the results obtained in this study could be used as basic research for the development of Hg(2+) detection, and the method developed could be a potential on-site screening tool for the rapid detection of Hg(2+) in different water samples without special instrumentation. All experimental variables that influence the test strip response were optimized and reported. Copyright © 2012 Elsevier B.V. All rights reserved.

Quasi-one-dimensional modes in strip plates: Theory and experiment

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

Arreola, A.; Báez, G.; Méndez-Sánchez, R. A.

2014-01-14

Using acoustic resonance spectroscopy we measure the elastic resonances of a strip rectangular plate with all its ends free. The experimental setup consist of a vector network analyzer, a high-fidelity audio amplifier, and electromagnetic-acoustic transducers. The one-dimensional modes are identified from the measured spectra by comparing them with theoretical predictions of compressional and bending modes of the plate modeled as a beam. The agreement between theory and experiment is excellent.

Sustainable, alternative farming practices as a means to simultaneously secure food production and reduce air pollution in East Asia

NASA Astrophysics Data System (ADS)

Tai, A. P. K.; Fung, K. M.; Yong, T.; Liu, X.

2015-12-01

Proper agricultural land management is essential for securing food supply and minimizing damage to the environment. Among available farming practices, relay strip intercropping and fertilizer application are commonly used, but to study their wider environmental implications and possible feedbacks we require an Earth system modeling framework. In this study, the effectiveness of a maize-soybean relay strip intercropping system and fertilizer reduction is investigated using a multi-model method. The DNDC (DeNitrification-DeComposition) model is used to simulate agricultural activities and their impacts on the environment through nitrogen emissions and changes in soil chemical composition. Crop yield, soil nutrient content and nitrogen emissions to the atmosphere in major agricultural regions of China are predicted under various cultivation scenarios. The GEOS-Chem global chemical transport model is then used to estimate the effects on downwind particle and ozone air pollution. We show that relay strip intercropping and optimal fertilization not only improve crop productivity, but also retain soil nutrients, reduce ammonia emission and mitigate downwind air pollution. By cutting 25% fertilization inputs but cultivating maize and soybean together in a relay strip intercropping system used with field studies, total crop production was improved slightly by 4.4% compared to monoculture with conventional amount of fertilizers. NH3 volatilization decreases by 29%, equivalent to saving the pollution-induced health damage costs by about US$2.5 billion per year. The possible feedback effects from atmospheric nitrogen deposition onto the croplands are also investigated. We show that careful management and better quantitative understanding of alternative farming practices hold huge potential in simultaneously addressing different global change issues including the food crisis, air pollution and climate change, and calls for greater collaboration between scientists, farmers and policy makers concerning these issues.

Tank Tests of Models of Flying Boat Hulls Having Longitudinal Steps

NASA Technical Reports Server (NTRS)

Allison, John M; Ward, Kenneth E

1936-01-01

Four models with longitudinal steps on the forebody were developed by modification of a model of a conventional hull and were tested in the National Advisory Committee for Aeronautics (NACA) tank. Models with longitudinal steps were found to have smaller resistance at high speed and greater resistance at low speed than the parent model that had the same afterbody but a conventional V-section forebody. The models with a single longitudinal step had better performance at hump speed and as low high-speed resistance except at very light loads. Spray strips at angles from 0 degrees to 45 degrees to the horizontal were fitted at the longitudinal steps and at the chine on one of the two step models having two longitudinal steps. The resistance and the height of the spray were less with each of the spray strips than without; the most favorable angle was found to lie between 15 degrees and 30 degrees.

Possible mechanism of the potent vasoconstrictor actions of ryanodine on femoral arteries from spontaneously hypertensive rats.

PubMed Central

Asano, M.; Kuwako, M.; Nomura, Y.; Ito, K. M.; Ito, K.; Uyama, Y.; Imaizumi, Y.; Watanabe, M.

1996-01-01

1. The Ca2+ buffering function of sarcoplasmic reticulum (SR) in the resting state of arteries from spontaneously hypertensive rats (SHR) was examined. Differences in the effects of ryanodine that removes the function of SR, on tension and cellular Ca2+ level were assessed in endothelium-denuded strips of femoral arteries from 13-week-old SHR and normotensive Wistar-Kyoto rats (WKY). 2. The addition of ryanodine to the resting strips caused a concentration-dependent contraction in SHR. This contraction was extremely small in WKY. In the presence of 10(-5) M ryanodine, caffeine (20 mM) failed to cause a further contraction in SHR, but it caused a small contraction in WKY. After washout of the strips with a Krebs solution, the resting tone was greatly elevated in SHR when compared with WKY. 3. The elevated resting tone in SHR strips was abolished by 10(-7) M nifedipine. The ryanodine-induced contraction was also abolished by 10(-7) M nifedipine. Nifedipine itself caused a relaxation from the resting tone of SHR strips, suggesting the maintenance of myogenic tone. 4. In strips preloaded with fura-PE3, the addition of 10(-5) M ryanodine caused a large and moderate elevation of cytosolic Ca2+ level ([Ca2+]i) in SHR and WKY, respectively. After washout, the resting [Ca2+]i was greatly elevated in SHR. The ryanodine-induced elevation of [Ca2+]i was decreased by 5 x 10(-6) M verapamil in SHR. Verapamil itself caused a decrease in resting [Ca2+]i which was significantly greater in SHR than in WKY, and caused a relaxation only in SHR. 5. The resting Ca2+ influx in arteries measured by a 5 min incubation with 45Ca was significantly increased in SHR when compared with WKY. The resting Ca2+ influx was not increased by 10(-5) M ryanodine in both SHR and WKY. The net cellular Ca2+ uptake in arteries measured by a 30 min incubation with 45Ca was decreased by 10(-5) M ryanodine in both strains. 6. The resting Ca2+ influx was decreased by 10(-7) M nifedipine in the SHR artery, but it was unchanged in the WKY artery. 7. These results suggest that (1) the Ca2+ influx via L-type voltage-dependent Ca2+ channels was increased in the resting state of the SHR femoral artery, (2) the greater part of the increased Ca2+ influx was buffered by Ca2+ uptake into the SR and some Ca2+ reached the myofilaments resulting in the maintenance of the myogenic tone, and (3) therefore the functional removal of SR by ryanodine caused a potent contraction in this artery. PMID:8799577

Exact solution of the hidden Markov processes.

PubMed

Saakian, David B

2017-11-01

We write a master equation for the distributions related to hidden Markov processes (HMPs) and solve it using a functional equation. Thus the solution of HMPs is mapped exactly to the solution of the functional equation. For a general case the latter can be solved only numerically. We derive an exact expression for the entropy of HMPs. Our expression for the entropy is an alternative to the ones given before by the solution of integral equations. The exact solution is possible because actually the model can be considered as a generalized random walk on a one-dimensional strip. While we give the solution for the two second-order matrices, our solution can be easily generalized for the L values of the Markov process and M values of observables: We should be able to solve a system of L functional equations in the space of dimension M-1.

Exact solution of the hidden Markov processes

NASA Astrophysics Data System (ADS)

Saakian, David B.

2017-11-01

We write a master equation for the distributions related to hidden Markov processes (HMPs) and solve it using a functional equation. Thus the solution of HMPs is mapped exactly to the solution of the functional equation. For a general case the latter can be solved only numerically. We derive an exact expression for the entropy of HMPs. Our expression for the entropy is an alternative to the ones given before by the solution of integral equations. The exact solution is possible because actually the model can be considered as a generalized random walk on a one-dimensional strip. While we give the solution for the two second-order matrices, our solution can be easily generalized for the L values of the Markov process and M values of observables: We should be able to solve a system of L functional equations in the space of dimension M -1 .

Rapid and Sensitive Detection of Protein Biomarker Using a Portable Fluorescence Biosensor based on Quantum Dots and a Lateral Flow Test Strip

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

Li, Zhaohui; Wang, Ying; Wang, Jun

2010-08-15

A portable fluorescence biosensor with rapid and ultrasensitive response for trace protein has been built up with quantum dots and lateral flow test strip. The superior signal brightness and high photostability of quantum dots are combined with the promising advantages of lateral flow test strip and resulted in high sensitivity, selectivity and speedy for protein detection. Nitrated ceruloplasmin, a significant biomarker for cardiovascular disease, lung cancer and stress response to smoking, was used as model protein to demonstrate the good performances of this proposed Qdot-based lateral flow test strip. Quantitative detection of nitrated ceruloplasmin was realized by recording the fluorescencemore » intensity of quantum dots captured on the test line. Under optimal conditions, this portable fluorescence biosensor displays rapid responses for nitrated ceruloplasmin in wide dynamic range with a detection limit of 0.1ng/mL (S/N=3). Furthermore, the biosensor was successfully utilized for spiked human plasma sample detection with the concentration as low as 1ng/mL. The results demonstrate that the quantum dot-based lateral flow test strip is capable for rapid, sensitive, and quantitative detection of nitrated ceruloplasmin and hold a great promise for point-of-care and in field analysis of other protein biomarkers.« less

The efficacy, sensitivity, and specificity of strip meniscometry in conjunction with tear function tests in the assessment of tear meniscus.

PubMed

Ibrahim, Osama M A; Dogru, Murat; Ward, Samantha K; Matsumoto, Yukihiro; Wakamatsu, Tais Hitomi; Ishida, Katsushi; Tsuyama, Atsushi; Kojima, Takashi; Shimazaki, Jun; Tsubota, Kazuo

2011-04-06

To evaluate the specificity and sensitivity of strip meniscometry (SM) testing in conjunction with tear function tests in the diagnosis of dry eye (DE) disease and to investigate the effect of SM on reflex tearing. One hundred seven left eyes of 107 patients with definite DE disease according to the Japanese DE diagnostic criteria and 68 left eyes of 68 age- and sex-matched control subjects were studied. Tear meniscus height (TMH) measurements, fluorescein tear film break-up time (FTBUT), fluorescein (F) and rose bengal (RB) staining, and Schirmer's test-1 (ST) were also performed. The assessment of reflex tearing before and after SM application was assessed with a graticule scale at the slit lamp and by optical coherence tomography. The sensitivity and specificity of SM alone and in combination with tear function tests were also sought. The SM scores, TMH measurements, FTBUTs, and STs were significantly lower in dry eye patients than in the controls (P < 0.001). The RB and F staining scores were significantly higher in the dry eye group than in the control group (P < 0.001). The meniscometry strips did not induce significant changes in relation to reflex tearing. SM had an acceptable sensitivity and specificity. SM is a swift, noninvasive, promising method of assessing tear meniscus volume. The combined SM and FTBUT examination appears to be a sensitive approach to the assessment of dry eye disease.

Carbon dioxide stripping in aquaculture -- part III: model verification

USGS Publications Warehouse

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

Based on conventional mass transfer models developed for oxygen, the use of the non-linear ASCE method, 2-point method, and one parameter linear-regression method were evaluated for carbon dioxide stripping data. For values of KLaCO2 < approximately 1.5/h, the 2-point or ASCE method are a good fit to experimental data, but the fit breaks down at higher values of KLaCO2. How to correct KLaCO2 for gas phase enrichment remains to be determined. The one-parameter linear regression model was used to vary the C*CO2 over the test, but it did not result in a better fit to the experimental data when compared to the ASCE or fixed C*CO2 assumptions.

Dynamic study for performance improvements of a thermo-mechanically bistable heat engine

NASA Astrophysics Data System (ADS)

Boughaleb, J.; Arnaud, A.; Monfray, S.; Cottinet, P. J.; Quenard, S.; Pitone, G.; Boeuf, F.; Guyomar, D.; Skotnicki, T.

2015-12-01

This paper focuses on a thermal study of a thermal energy harvester based on the coupling of a bimetallic strip heat engine with a piezoelectric membrane for wasted heat scavenging. Such a harvester is dedicated to power autonomous systems such as wireless sensor nodes. For a better understanding of the working principle of the system, it is compulsory to have a good understanding of the thermal specificities and phenomenon taking place inside the harvester. Attention is consequently focused on the thermal modeling of the harvester in static mode using the equivalence between the electrical and thermal quantities. This first modeling step allowed the improvement of the thermal properties inside the system by increasing the thermal gradient across it. However, the bimetal being the active part of the system has not been taken into account in this model and shadow zones persisted regarding the bimetal operation windows as a function of its snapping temperatures and hysteresis. To overcome this, a dynamic model is proposed in this paper taking into account the bimetal as a switched capacitance alternatively in contact with the hot source and the cold surface. This last model completed the static one by predicting the bimetal's operation windows in function of its intrinsic properties and the operation range evolution in function of the snapping temperature first and then in function of the bimetal thermal hysteresis. Moreover, experimental measurements enable to validate the proposed model and to point out the most powerful bimetals for scavenging higher amounts of power.

Reevaluation of the non-lesional dry skin in atopic dermatitis by acute barrier disruption: an abnormal permeability barrier homeostasis with defective processing to generate ceramide.

PubMed

Sugiura, Ayumi; Nomura, Tsuyoshi; Mizuno, Atsuko; Imokawa, Genji

2014-07-01

Atopic dermatitis is characterized by disruption of the cutaneous barrier due to reduced ceramide levels even in non-lesional dry skin. Following further acute barrier disruption by repeated tape strippings, we re-characterized the non-lesional dry skin of subjects with atopic dermatitis, which shows significantly reduced levels of barrier function and ceramide but not of beta-glucocerebrosidase activity. For the first time, we report an abnormal trans-epidermal water loss homeostasis in which delayed recovery kinetics of trans-epidermal water loss occurred on the first day during the 4 days after acute barrier disruption compared with healthy control skin. Interestingly, whereas the higher ceramide level in the stratum corneum of healthy control skin was further significantly up-regulated at 4 days post-tape stripping, the lower ceramide level in the stratum corneum of subjects with atopic dermatitis was not significantly changed. In a parallel study, whereas beta-glucocerebrosidase activity at 4 days post-tape stripping was significantly up-regulated in healthy control skin compared with before tape stripping, the level of that activity remained substantially unchanged in atopic dermatitis. These findings indicate that subjects with atopic dermatitis have a defect in sphingolipid-metabolic processing that generates ceramide in the interface between the stratum corneum and the epidermis. The results also support the notion that the continued disruption of barrier function in atopic dermatitis non-lesional skin is associated with the impaired homeostasis of a ceramide-generating process, which underscores an atopy-specific inflammation-triggered ceramide deficiency that is distinct from other types of dermatitis.

An extended UTD analysis for the scattering and diffraction from cubic polynomial strips

NASA Technical Reports Server (NTRS)

Constantinides, E. D.; Marhefka, R. J.

1993-01-01

Spline and polynomial type surfaces are commonly used in high frequency modeling of complex structures such as aircraft, ships, reflectors, etc. It is therefore of interest to develop an efficient and accurate solution to describe the scattered fields from such surfaces. An extended Uniform Geometrical Theory of Diffraction (UTD) solution for the scattering and diffraction from perfectly conducting cubic polynomial strips is derived and involves the incomplete Airy integrals as canonical functions. This new solution is universal in nature and can be used to effectively describe the scattered fields from flat, strictly concave or convex, and concave convex boundaries containing edges. The classic UTD solution fails to describe the more complicated field behavior associated with higher order phase catastrophes and therefore a new set of uniform reflection and first-order edge diffraction coefficients is derived. Also, an additional diffraction coefficient associated with a zero-curvature (inflection) point is presented. Higher order effects such as double edge diffraction, creeping waves, and whispering gallery modes are not examined. The extended UTD solution is independent of the scatterer size and also provides useful physical insight into the various scattering and diffraction processes. Its accuracy is confirmed via comparison with some reference moment method results.

Motion Driven by Strain Gradient Fields

PubMed Central

Wang, Chao; Chen, Shaohua

2015-01-01

A new driving mechanism for direction-controlled motion of nano-scale objects is proposed, based on a model of stretching a graphene strip linked to a rigid base with linear springs of identical stiffness. We find that the potential energy difference induced by the strain gradient field in the graphene strip substrate can generate sufficient force to overcome the static and kinetic friction forces between the nano-flake and the strip substrate, resulting in the nanoscale flake motion in the direction of gradient reduction. The dynamics of the nano-flake can be manipulated by tuning the stiffness of linear springs, stretching velocity and the flake size. This fundamental law of directional motion induced by strain gradient could be very useful for promising designs of nanoscale manipulation, transportation and smart surfaces. PMID:26323603

Hot Gas Halos in Galaxies

NASA Astrophysics Data System (ADS)

Mulchaey, John

Most galaxy formation models predict that massive low-redshift disk galaxies are embedded in extended hot halos of externally accreted gas. Such gas appears necessary to maintain ongoing star formation in isolated spirals like the Milky Way. To explain the large population of red galaxies in rich groups and clusters, most galaxy evolution models assume that these hot gas halos are stripped completely when a galaxy enters a denser environment. This simple model has been remarkably successful at reproducing many observed properties of galaxies. Although theoretical arguments suggest hot gas halos are an important component in galaxies, we know very little about this gas from an observational standpoint. In fact, previous observations have failed to detect soft X-ray emission from such halos in disk galaxies. Furthermore, the assumption that hot gas halos are stripped completely when a galaxy enters a group or cluster has not been verified. We propose to combine proprietary and archival XMM-Newton observations of galaxies in the field, groups and clusters to study how hot gas halos are impacted by environment. Our proposed program has three components: 1) The deepest search to date for a hot gas halo in a quiescent spiral galaxy. A detection will confirm a basic tenet of disk galaxy formation models, whereas a non-detection will seriously challenge these models and impose new constraints on the growth mode and feedback history of disk galaxies. 2) A detailed study of the hot gas halos properties of field early-type galaxies. As environmental processes such as stripping are not expected to be important in the field, a study of hot gas halos in this environment will allow us to better understand how feedback and other internal processes impact hot gas halos. 3) A study of hot gas halos in the outskirts of groups and clusters. By comparing observations with our suite of simulations we can begin to understand what role the stripping of hot gas halos plays in galaxy evolution.

The large-scale distribution of galaxies

NASA Technical Reports Server (NTRS)

Geller, Margaret J.

1989-01-01

The spatial distribution of galaxies in the universe is characterized on the basis of the six completed strips of the Harvard-Smithsonian Center for Astrophysics redshift-survey extension. The design of the survey is briefly reviewed, and the results are presented graphically. Vast low-density voids similar to the void in Bootes are found, almost completely surrounded by thin sheets of galaxies. Also discussed are the implications of the results for the survey sampling problem, the two-point correlation function of the galaxy distribution, the possibility of detecting large-scale coherent flows, theoretical models of large-scale structure, and the identification of groups and clusters of galaxies.

Geology, geomorphology and hydrology of the Wadi Gaza catchment, Gaza Strip, Palestine

NASA Astrophysics Data System (ADS)

Zaineldeen, Usama; Aish, Adnan

2012-11-01

The geological, geomorphological and hydrological features along the course of the Wadi Gaza (Palestine) are discussed. The study confirms the existence of Pleistocene loess sediments along the Wadi. Wadi Gaza is characterized by meandering features along its course. The watershed of Wadi Gaza is estimated to cover more than 3500 km2 of the Northern Negev Desert and the Hebron Mountains as well as the small catchment sub-area in the Gaza Strip itself. Storm water drains the hills and mountains of Hebron and the northern Negev desert, accumulates in the Beer-Sheva area, crosses the Gaza Strip and discharges into the Mediterranean Sea. In winter the Wadi Gaza brings about 20 million cubic meter of rainwater into the area. Field investigations demonstrate the existence of loess sediments in the Wadi Gaza area, deposited during the dry periods that affected the area during the Pleistocene. The Digital Elevation Model (DEM) applied for the Gaza Strip confirmed the existence of three Kurkar ridges within the Gaza Strip. Arranged from west to east (i) Sheikh Ejlin Ridge extends up to the current coastline in the west, (ii) Al Montar Ridge occurs near the armistice line in the east and (iii) Bait Hanon Ridge of which a part is present to the northeast of the Gaza Strip and a part to the east of the armistice line (the intermediate part not being accessible for observation due to political reasons. It is considered as a security zone). All three ridges are running NE-SW, parallel to the Mediterranean coastline.

Energy-Efficient Bioalcohol Recovery by Gel Stripping

NASA Astrophysics Data System (ADS)

Godbole, Rutvik; Ma, Lan; Hedden, Ronald

2014-03-01

Design of energy-efficient processes for recovering butanol and ethanol from dilute fermentations is a key challenge facing the biofuels industry due to the high energy consumption of traditional multi-stage distillation processes. Gel stripping is an alternative purification process by which a dilute alcohol is stripped from the fermentation product by passing it through a packed bed containing particles of a selectively absorbent polymeric gel material. The gel must be selective for the alcohol, while swelling to a reasonable degree in dilute alcohol-water mixtures. To accelerate materials optimization, a combinatorial approach is taken to screen a matrix of copolymer gels having orthogonal gradients in crosslinker concentration and hydrophilicity. Using a combination of swelling in pure solvents, the selectivity and distribution coefficients of alcohols in the gels can be predicted based upon multi-component extensions of Flory-Rehner theory. Predictions can be validated by measuring swelling in water/alcohol mixtures and conducting h HPLC analysis of the external liquid. 95% + removal of butanol from dilute aqueous solutions has been demonstrated, and a mathematical model of the unsteady-state gel stripping process has been developed. NSF CMMI Award 1335082.

The Fate of Gas-rich Satellites in Clusters

NASA Astrophysics Data System (ADS)

Safarzadeh, Mohammadtaher; Scannapieco, Evan

2017-11-01

We investigate the stellar mass-loss of gas-rich galaxies falling into clusters due to the change in the gravitational potential caused by the ram-pressure-stripping of their gas. We model the satellites with exponential stellar and gas disk profiles, assume rapid ram-pressure-stripping, and follow the stellar orbits in the shocked potential. Due to the change of the potential, the stars move from circular orbits to elliptical orbits with apocenters that are often outside the tidal radius, causing those stars to be stripped. We explore the impact of the redshift of infall, gas fraction, satellite halo mass, and cluster mass on this process. The puffing of the satellites makes them appear as ultra-diffuse galaxies, and the stripped stars contribute to the intracluster light. Our results show that these effects are most significant for less massive satellites, which have larger gas fractions when they are accreted into clusters. The preferential destruction of low-mass systems causes the red fraction of cluster galaxies to be smaller at lower masses, an observation that is otherwise difficult to explain.

Vibration isolation using extreme geometric nonlinearity

NASA Astrophysics Data System (ADS)

Virgin, L. N.; Santillan, S. T.; Plaut, R. H.

2008-08-01

A highly deformed, slender beam (or strip), attached to a vertically oscillating base, is used in a vibration isolation application to reduce the motion of a supported mass. The isolator is a thin strip that is bent so that the two ends are clamped together, forming a loop. The clamped ends are attached to an excitation source and the supported system is attached at the loop midpoint directly above the base. The strip is modeled as an elastica, and the resulting nonlinear boundary value problem is solved numerically using a shooting method. First the equilibrium shapes of the loop with varying static loads and lengths are studied. The analysis reveals a large degree of stiffness tunability; the stiffness is dependent on the geometric configuration, which itself is determined by the supported mass, loop length, and loop self-weight. Free vibration frequencies and mode shapes are also found. Finally, the case of forced vibration is studied, and the displacement transmissibility over a large range of forcing frequencies is determined for varying parameter values. Experiments using polycarbonate strips are conducted to verify equilibrium and dynamic behavior.

Hollow Au-Ag Nanoparticles Labeled Immunochromatography Strip for Highly Sensitive Detection of Clenbuterol

NASA Astrophysics Data System (ADS)

Wang, Jingyun; Zhang, Lei; Huang, Youju; Dandapat, Anirban; Dai, Liwei; Zhang, Ganggang; Lu, Xuefei; Zhang, Jiawei; Lai, Weihua; Chen, Tao

2017-01-01

The probe materials play a significant role in improving the detection efficiency and sensitivity of lateral-flow immunochromatographic test strip (ICTS). Unlike conventional ICTS assay usually uses single-component, solid gold nanoparticles as labeled probes, in our present study, a bimetallic, hollow Au-Ag nanoparticles (NPs) labeled ICTS was successfully developed for the detection of clenbuterol (CLE). The hollow Au-Ag NPs with different Au/Ag mole ratio and tunable size were synthesized by varying the volume ratio of [HAuCl4]:[Ag NPs] via the galvanic replacement reaction. The surface of hollow Ag-Au NPs was functionalized with 11-mercaptoundecanoic acid (MUA) for further covalently bonded with anti-CLE monoclonal antibody. Overall size of the Au-Ag NPs, size of the holes within individual NPs and also Au/Ag mole ratio have been systematically optimized to amplify both the visual inspection signals and the quantitative data. The sensitivity of optimized hollow Au-Ag NPs probes has been achieved even as low as 2 ppb in a short time (within 15 min), which is superior over the detection performance of conventional test strip using Au NPs. The optimized hollow Au-Ag NPs labeled test strip can be used as an ideal candidate for the rapid screening of CLE in food samples.

Strip dielectric wave guide antenna-for the measurement of dielectric constant of low-loss materials

NASA Astrophysics Data System (ADS)

Rastogi, Alok Kumar; Tiwari, A. K.; Shrivastava, R. P.

1993-07-01

The value of dielectric constant are the most important parameters in material science technology. In micro-wave and millimeter wave circuits using dielectric materials the values of this parameters should be known accurately. It is observed that the number of methods are reported in litrature, however these methods impose difficulties in experimentation and are not very accurate. In this paper a novel approach to the measurement of the dielectric constant of low loss materials at micro-wave and millimeter wave frequencies has been discussed. In this method by using antenna theory, a metallic strip dielectric guide is taken in to constideration and band reject phenomenon of dielectric antenna is used. Frequency response of an antenna in band reject mode is a function of the dimensional parameters, such as the metallic strip period, the profile of the metallic strip and the dielectric constant of the material used. Hence if one measure the frequency responce of the antenna in band reject mode, the dielectric constant of the material is determined provided all other parameters are known. This method gives a direct measure of dielectric constant and is quite accurate as computer techniques are used for evaluating the dielectric constant. This method verified experimentally also.

The effects of anisotropy on the nonlinear behavior of bridged cracks in long strips

NASA Technical Reports Server (NTRS)

Ballarini, R.; Luo, H. A.

1994-01-01

A model which can be used to predict the two-dimensional nonlinear behavior of bridged cracks in orthotropic strips is presented. The results obtained using a singular integral equation formulation which incorporates the anisotropy rigorously show that, although the effects of anisotropy are significant, the nondimensional quantities employed by Cox and Marshall can generate nearly universal results (R-curves, for example) for different levels of relative anisotropy. The role of composite constituent properties in the behavior of bridged cracks is clarified.

A new hybrid numerical scheme for simulating fault ruptures with near-fault bulk inhomogeneities

NASA Astrophysics Data System (ADS)

Hajarolasvadi, S.; Elbanna, A. E.

2017-12-01

The Finite Difference (FD) and Boundary Integral (BI) Method have been extensively used to model spontaneously propagating shear cracks, which can serve as a useful idealization of natural earthquakes. While FD suffers from artificial dispersion and numerical dissipation and has a large computational cost as it requires the discretization of the whole volume of interest, it can be applied to a wider range of problems including ones with bulk nonlinearities and heterogeneities. On the other hand, in the BI method, the numerical consideration is confined to the crack path only, with the elastodynamic response of the bulk expressed in terms of integral relations between displacement discontinuities and tractions along the crack. Therefore, this method - its spectral boundary integral (SBI) formulation in particular - is much faster and more computationally efficient than other bulk methods such as FD. However, its application is restricted to linear elastic bulk and planar faults. This work proposes a novel hybrid numerical scheme that combines FD and the SBI to enable treating fault zone nonlinearities and heterogeneities with unprecedented resolution and in a more computationally efficient way. The main idea of the method is to enclose the inhomgeneities in a virtual strip that is introduced for computational purposes only. This strip is then discretized using a volume-based numerical method, chosen here to be the finite difference method while the virtual boundaries of the strip are handled using the SBI formulation that represents the two elastic half spaces outside the strip. Modeling the elastodynamic response in these two halfspaces needs to be carried out by an Independent Spectral Formulation before joining them to the strip with the appropriate boundary conditions. Dirichlet and Neumann boundary conditions are imposed on the strip and the two half-spaces, respectively, at each time step to propagate the solution forward. We demonstrate the validity of the approach using two examples for dynamic rupture propagation: one in the presence of a low velocity layer and the other in which off-fault plasticity is permitted. This approach is more computationally efficient than pure FD and expands the range of applications of SBI beyond the current state of the art.

Developing a vacuum thermal stripping - acid absorption process for ammonia recovery from anaerobic digester effluent.

PubMed

Ukwuani, Anayo T; Tao, Wendong

2016-12-01

To prevent acetoclastic methanogens from ammonia inhibition in anaerobic digestion of protein-rich substrates, ammonia needs to be removed or recovered from digestate. This paper presents an innovative ammonia recovery process that couples vacuum thermal stripping with acid absorption. Ammonia is stripped out of digestate boiling at a temperature below the normal boiling point due to vacuum. Stripped ammonia is absorbed to a sulfuric acid solution, forming ammonium sulfate crystals as a marketable product. Three common types of digestate were found to have boiling point temperature-vacuum curves similar to water. Seven combinations of boiling temperature and vacuum (50 °C 16.6 kPa, 58 °C 20.0 kPa, 65 °C 25.1 kPa, 70 °C 33.6 kPa, 80 °C 54.0 kPa, 90 °C 74.2 kPa, and 100 °C 101.3 kPa) were tested for batch stripping of ammonia in dairy manure digestate. 93.3-99.9% of ammonia was stripped in 3 h. The Lewis-Whitman model fitted ammonia stripping process well. Ammonia mass transfer coefficient was significantly higher at boiling temperature 65-100 °C and vacuum pressure 25.1-101.3 kPa than 50-58 °C and 16.6-20.0 kPa. The low ammonia saturation concentrations (0-24 mg N/L) suggested a large driving force to strip ammonia. The optimum boiling point temperature - vacuum pressure for ammonia recovery in a recirculation line of a mesophilic digester was 65 °C and 25.1 kPa, at which the ammonia mass transfer coefficient was as high as 37.3 mm/h. Installation of a demister and liquid trap could avoid negative effects of higher stripping temperature and stronger vacuum on formation of ammonium sulfate crystals. Pilot tests demonstrated that high-purity ammonium sulfate crystals could be produced by controlling sulfuric acid content and maintaining acid solution saturated with ammonium sulfate. Although volatile organic compounds such as cyclohexene were found in the final acid solutions, no volatile organic compounds were found in the recovered crystals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Carbon Nanotube Tape Vibrating Gyroscope

NASA Technical Reports Server (NTRS)

Tucker, Dennis Stephen (Inventor)

2016-01-01

A vibrating gyroscope includes a piezoelectric strip having length and width dimensions. The piezoelectric strip includes a piezoelectric material and carbon nanotubes (CNTs) substantially aligned and polled along the strip's length dimension. A spindle having an axis of rotation is coupled to the piezoelectric strip. The axis of rotation is parallel to the strip's width dimension. A first capacitance sensor is mechanically coupled to the spindle for rotation therewith. The first capacitance sensor is positioned at one of the strip's opposing ends and is spaced apart from one of the strip's opposing faces. A second capacitance sensor is mechanically coupled to the spindle for rotation therewith. The second capacitance sensor is positioned at another of the strip's opposing ends and is spaced apart from another of the strip's opposing faces. A voltage source applies an AC voltage to the piezoelectric strip.

Fiber Reinforced Composite Cores and Panels

NASA Technical Reports Server (NTRS)

Day, Stephen W. (Inventor); Campbell, G. Scott (Inventor); Tilton, Danny E. (Inventor); Stoll, Frederick (Inventor); Sheppard, Michael (Inventor); Banerjee, Robin (Inventor)

2013-01-01

A fiber reinforced core panel is formed from strips of plastics foam helically wound with layers of rovings to form webs which may extend in a wave pattern or may intersect transverse webs. Hollow tubes may replace foam strips. Axial rovings cooperate with overlying helically wound rovings to form a beam or a column. Wound roving patterns may vary along strips for structural efficiency. Wound strips may alternate with spaced strips, and spacers between the strips enhance web buckling strength. Continuously wound rovings between spaced strips permit folding to form panels with reinforced edges. Continuously wound strips are helically wrapped to form annular structures, and composite panels may combine both thermoset and thermoplastic resins. Continuously wound strips or strip sections may be continuously fed either longitudinally or laterally into molding apparatus which may receive skin materials to form reinforced composite panels.

Ground-state entropy of the potts antiferromagnet with next-nearest-neighbor spin-spin couplings on strips of the square lattice

PubMed

Chang; Shrock

2000-10-01

We present exact calculations of the zero-temperature partition function (chromatic polynomial) and W(q), the exponent of the ground-state entropy, for the q-state Potts antiferromagnet with next-nearest-neighbor spin-spin couplings on square lattice strips, of width L(y)=3 and L(y)=4 vertices and arbitrarily great length Lx vertices, with both free and periodic boundary conditions. The resultant values of W for a range of physical q values are compared with each other and with the values for the full two-dimensional lattice. These results give insight into the effect of such nonnearest-neighbor couplings on the ground-state entropy. We show that the q=2 (Ising) and q=4 Potts antiferromagnets have zero-temperature critical points on the Lx-->infinity limits of the strips that we study. With the generalization of q from Z+ to C, we determine the analytic structure of W(q) in the q plane for the various cases.

Stress intensity factors of composite orthotropic plates containing periodic buffer strips

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1978-01-01

The fracture problem of laminated plates which consist of bonded orthotropic layers is studied. The fields equations for an elastic orthotropic body are transformed to give the displacement and stress expressions for each layer or strip. The unknown functions in these expressions are found by satisfying the remaining boundary and continuity conditions. A system of singular integral equations is obtained from the mixed boundary conditions. The singular behavior around the crack tip and at the bimaterial interface is studied. The stress intensity factors are computed for various material combinations and various crack geometries. The results are discussed and are compared with those for isotropic materials.

Residence time of symmetric random walkers in a strip with large reflective obstacles

NASA Astrophysics Data System (ADS)

Ciallella, Alessandro; Cirillo, Emilio N. M.; Sohier, Julien

2018-05-01

We study the effect of a large obstacle on the so-called residence time, i.e., the time that a particle performing a symmetric random walk in a rectangular (two-dimensional, 2D) domain needs to cross the strip. We observe complex behavior: We find out that the residence time does not depend monotonically on the geometric properties of the obstacle, such as its width, length, and position. In some cases, due to the presence of the obstacle, the mean residence time is shorter with respect to the one measured for the obstacle-free strip. We explain the residence time behavior by developing a one-dimensional (1D) analog of the 2D model where the role of the obstacle is played by two defect sites having smaller probability to be crossed with respect to all the other regular sites. The 1D and 2D models behave similarly, but in the 1D case we are able to compute exactly the residence time, finding a perfect match with the Monte Carlo simulations.

Transparent Helium in Stripped Envelope Supernovae

NASA Astrophysics Data System (ADS)

Piro, Anthony L.; Morozova, Viktoriya S.

2014-09-01

Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main SN light curve, and thus the total helium mass may be difficult to measure from simple light curve modeling. Conversely, such modeling may be more useful for constraining the mass of the carbon/oxygen core of the SN progenitor. Other stripped envelope SNe show higher velocities and larger velocity gradients, which require an additional opacity source (perhaps the mixing of heavier elements or radioactive nickel) to prevent the helium from being transparent. We discuss ways in which similar analysis can provide insights into the differences and similarities between SNe Ib and Ic, which will lead to a better understanding of their respective formation mechanisms.

Removal of urothelium affects bladder contractility and release of ATP but not release of NO in rat urinary bladder.

PubMed

Munoz, Alvaro; Gangitano, David A; Smith, Christopher P; Boone, Timothy B; Somogyi, George T

2010-05-24

The objective of our work was to investigate both the contractile function and the release of ATP and NO from strips of bladder tissue after removal of the urothelium. The method of removal was a gentle swabbing motion rather than a sharp surgical cutting to separate the urothelium from the smooth muscle. The contractile response and ATP and NO release were measured in intact as well as on swabbed preparations. The removal of the urothelial layer was affirmed microscopically. After the swabbing, the smaller contractions were evoked by electrical as well as by chemical stimulation (50 microM carbachol or 50 microM alpha, beta meATP). Electrical stimulation, carbachol and substance P (5 microM) evoked lower release of ATP in the swabbed strips than in intact strips. Although release of NO evoked by electrical stimulation or substance P was not changed, release of NO evoked by carbachol was significantly less in the swabbed preparations. Since swabbing removes only the urothelium, the presence of the suburothelial layer may explain the difference between our findings and those of others who found an increase in contractility. Evoked release of ATP is reduced in swabbed strips, indicating that ATP derives solely from the urothelium. On the other hand, electrical stimulation and substance P evoke identical degrees of NO release in both intact and swabbed preparations, suggesting that NO can be released from the suburothelium. Conversely, carbachol-induced release of NO is lower in swabbed strips, implying that the cholinergic receptors (muscarinic or nicotinic) are located in the upper layer of the urothelium.

Diabetes attenuates urothelial modulation of detrusor contractility and spontaneous activity.

PubMed

Wang, Yi; Tar, Moses T; Fu, Shibo; Melman, Arnold; Davies, Kelvin P

2014-10-01

To investigate the effect of diabetes on urothelial modulation of bladder contractility. Bladder strips (urothelium intact or denuded) were prepared from 8-week-old streptozotocin-induced diabetic (n = 19) and non-diabetic control rats (n = 10). The effect of modulators of MaxiK (iberiotoxin and tetraethylammonium) and Kv7 (XE991 and retigabine) potassium channel activity were investigated for their effects on both carbachol-induced force generation and spontaneous contractile activity. In bladder strips from non-diabetic animals, the presence of the urothelium resulted in marked sensitivity to carbachol-induced force generation by modulators of MaxiK and Kv7 channel activity, whereas in the diabetic animal urothelial sensitivity to these agents was significantly diminished. Urothelial-intact bladder strips from non-diabetic animals were more sensitive to modulators of Kv7 activity in reducing the amplitude of spontaneous phasic contractions than urothelial-denuded bladder strips, whereas in diabetic animals the presence or absence of the urothelium did not alter the sensitivity to modulators of Kv7 activity. Spontaneous activity in the presence of tetraethylammonium was not affected by the urothelium in bladder strips from either diabetic or non-diabetic animals. The presence of the urothelium in bladders from non-diabetic animals modulates the activity of potassium blockers to affect bladder contractility, whereas in the diabetic bladder this effect is attenuated. These findings could help to explain the lack of success of pharmaceutical treatments targeting potassium channels to treat bladder pathology in patients with diseases imparing urothelial function. © 2014 The Japanese Urological Association.

Differences in time to peak carbachol-induced contractions between circular and longitudinal smooth muscles of mouse ileum.

PubMed

Azuma, Yasu-Taka; Samezawa, Nanako; Nishiyama, Kazuhiro; Nakajima, Hidemitsu; Takeuchi, Tadayoshi

2016-01-01

The muscular layer in the GI tract consists of an inner circular muscular layer and an outer longitudinal muscular layer. Acetylcholine (ACh) is the representative neurotransmitter that causes contractions in the gastrointestinal tracts of most animal species. There are many reports of muscarinic receptor-mediated contraction of longitudinal muscles, but few studies discuss circular muscles. The present study detailed the contractile response in the circular smooth muscles of the mouse ileum. We used small muscle strips (0.2 mm × 1 mm) and large muscle strips (4 × 4 mm) isolated from the circular and longitudinal muscle layers of the mouse ileum to compare contraction responses in circular and longitudinal smooth muscles. The time to peak contractile responses to carbamylcholine (CCh) were later in the small muscle strips (0.2 × 1 mm) of circular muscle (5.7 min) than longitudinal muscles (0.4 min). The time to peak contractile responses to CCh in the large muscle strips (4 × 4 mm) were also later in the circular muscle (3.1 min) than the longitudinal muscle (1.4 min). Furthermore, a muscarinic M2 receptor antagonist and gap junction inhibitor significantly delayed the time to peak contraction of the large muscle strips (4 × 4 mm) from the circular muscular layer. Our findings indicate that muscarinic M2 receptors in the circular muscular layer of mouse ileum exert a previously undocumented function in gut motility via the regulation of gap junctions.

Model-based tomographic reconstruction

DOEpatents

Chambers, David H; Lehman, Sean K; Goodman, Dennis M

2012-06-26

A model-based approach to estimating wall positions for a building is developed and tested using simulated data. It borrows two techniques from geophysical inversion problems, layer stripping and stacking, and combines them with a model-based estimation algorithm that minimizes the mean-square error between the predicted signal and the data. The technique is designed to process multiple looks from an ultra wideband radar array. The processed signal is time-gated and each section processed to detect the presence of a wall and estimate its position, thickness, and material parameters. The floor plan of a building is determined by moving the array around the outside of the building. In this paper we describe how the stacking and layer stripping algorithms are combined and show the results from a simple numerical example of three parallel walls.

Spin Bose-metal phase in a spin- (1)/(2) model with ring exchange on a two-leg triangular strip

NASA Astrophysics Data System (ADS)

Sheng, D. N.; Motrunich, Olexei I.; Fisher, Matthew P. A.

2009-05-01

Recent experiments on triangular lattice organic Mott insulators have found evidence for a two-dimensional (2D) spin liquid in close proximity to the metal-insulator transition. A Gutzwiller wave function study of the triangular lattice Heisenberg model with a four-spin ring exchange term appropriate in this regime has found that the projected spinon Fermi sea state has a low variational energy. This wave function, together with a slave particle-gauge theory analysis, suggests that this putative spin liquid possesses spin correlations that are singular along surfaces in momentum space, i.e., “Bose surfaces.” Signatures of this state, which we will refer to as a “spin Bose metal” (SBM), are expected to manifest in quasi-one-dimensional (quasi-1D) ladder systems: the discrete transverse momenta cut through the 2D Bose surface leading to a distinct pattern of 1D gapless modes. Here, we search for a quasi-1D descendant of the triangular lattice SBM state by exploring the Heisenberg plus ring model on a two-leg triangular strip (zigzag chain). Using density matrix renormalization group (DMRG) supplemented by variational wave functions and a bosonization analysis, we map out the full phase diagram. In the absence of ring exchange the model is equivalent to the J1-J2 Heisenberg chain, and we find the expected Bethe-chain and dimerized phases. Remarkably, moderate ring exchange reveals a new gapless phase over a large swath of the phase diagram. Spin and dimer correlations possess singular wave vectors at particular “Bose points” (remnants of the 2D Bose surface) and allow us to identify this phase as the hoped for quasi-1D descendant of the triangular lattice SBM state. We use bosonization to derive a low-energy effective theory for the zigzag spin Bose metal and find three gapless modes and one Luttinger parameter controlling all power law correlations. Potential instabilities out of the zigzag SBM give rise to other interesting phases such as a period-3 valence bond solid or a period-4 chirality order, which we discover in the DMRG. Another interesting instability is into a spin Bose-metal phase with partial ferromagnetism (spin polarization of one spinon band), which we also find numerically using the DMRG.

SALT, a dedicated readout chip for high precision tracking silicon strip detectors at the LHCb Upgrade

NASA Astrophysics Data System (ADS)

Bugiel, Sz.; Dasgupta, R.; Firlej, M.; Fiutowski, T.; Idzik, M.; Kuczynska, M.; Moron, J.; Swientek, K.; Szumlak, T.

2016-02-01

The Upstream Tracker (UT) silicon strip detector, one of the central parts of the tracker system of the modernised LHCb experiment, will use a new 128-channel readout ASIC called SALT. It will extract and digitise analogue signals from the UT sensors, perform digital signal processing and transmit a serial output data. The SALT is being designed in CMOS 130 nm process and uses a novel architecture comprising of analog front-end and fast (40 MSps) ultra-low power (<0.5 mW) 6-bit ADC in each channel. The prototype ASICs of important functional blocks, like analogue front-end, 6-bit SAR ADC, PLL, and DLL, were designed, fabricated and tested. A prototype of an 8-channel version of the SALT chip, comprising all important functionalities was also designed and fabricated. The architecture and design of the SALT, together with the selected preliminary tests results, are presented.

Apoplastic Diffusion Barriers in Arabidopsis

PubMed Central

Schreiber, Lukas; Franke, Rochus Benni; Geldner, Niko; Reina-Pinto, José J.; Kunst, Ljerka

2013-01-01

During the development of Arabidopsis and other land plants, diffusion barriers are formed in the apoplast of specialized tissues within a variety of plant organs. While the cuticle of the epidermis is the primary diffusion barrier in the shoot, the Casparian strips and suberin lamellae of the endodermis and the periderm represent the diffusion barriers in the root. Different classes of molecules contribute to the formation of extracellular diffusion barriers in an organ- and tissue-specific manner. Cutin and wax are the major components of the cuticle, lignin forms the early Casparian strip, and suberin is deposited in the stage II endodermis and the periderm. The current status of our understanding of the relationships between the chemical structure, ultrastructure and physiological functions of plant diffusion barriers is discussed. Specific aspects of the synthesis of diffusion barrier components and protocols that can be used for the assessment of barrier function and important barrier properties are also presented. PMID:24465172

Possible health effects of liquefied petroleum gas on workers at filling and distribution stations of Gaza governorates.

PubMed

Sirdah, M M; Al Laham, N A; El Madhoun, R A

2013-03-01

Liquefied petroleum gas (LPG) is widely used in the Gaza Strip for domestic purposes, in agriculture and industry and, illegally, in cars. This study aimed to identify possible health effects on workers exposed to LPG in Gaza governorates. Data were collected by a questionnaire interview, and haematological and biochemical analyses of venous blood samples were made from 30 workers at filling and distribution stations and 30 apparently healthy controls. Statistically significant differences were found in all self-reported health-related complaints among LPG workers versus controls. LPG workers had significantly higher values of red blood cell counts, haemoglobin, haematocrit mean corpuscular haemoglobin and platelet counts. They also had significantly higher values of kidney function tests (urea, creatinine and uric acid) and liver function enzyme activities (aspartate aminotransferase and alanine aminotransferase). LPG workers at Gaza Strip petroleum stations are at higher risk for health-related symptoms and clinical abnormalities.

Metal distribution in the intracluster medium: a comprehensive numerical study of twelve galaxy clusters

NASA Astrophysics Data System (ADS)

Höller, Harald; Stöckl, Josef; Benson, Andrew; Haider, Markus; Steinhauser, Dominik; Lovisari, Lorenzo; Pranger, Florian

2014-09-01

We present a simulation setup for studying the dynamical and chemical evolution of the intracluster medium (ICM) and analyze a sample of 12 galaxy clusters that are diverse both kinetically (pre-merger, merging, virialized) and in total mass (Mvir = 1.17 × 1014 - 1.06 × 1015 M⊙). We analyzed the metal mass fraction in the ICM as a function of redshift and discuss radial trends as well as projected 2D metallicity maps. The setup combines high mass resolution N-body simulations with the semi-analytical galaxy formation model Galacticus for consistent treatment of the subgrid physics (such as galactic winds and ram-pressure stripping) in the cosmological hydrodynamical simulations. The interface between Galacticus and the hydro simulation of the ICM with FLASH is discussed with respect to observations of star formation rate histories, radial star formation trends in galaxy clusters, and the metallicity at different redshifts. As a test for the robustness of the wind model, we compare three prescriptions from different approaches. For the wind model directly taken from Galacticus, we find mean ICM metallicities between 0.2-0.8 Z⊙ within the inner 1 Mpc at z = 0. The main contribution to the metal mass fraction comes from galactic winds. The outflows are efficiently mixed in the ICM, leading to a steady homogenization of metallicities until ram-pressure stripping becomes effective at low redshifts. We find a very peculiar and yet common drop in metal mass fractions within the inner ~200 kpc of the cool cores, which is due to a combination of wind suppression by outer pressure within our model and a lack of mixing after the formation of these dense regions. Appendix A is available in electronic form at http://www.aanda.org

Development of a rate model to investigate contributions of anatomic and physiologic determinants of in vivo skin permeation

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

Fleischer, N.M.

The skin is a heterogeneous, bi-directional impediment to chemical flux, in which the stratum corneum is a major, though not the sole, rate-limiting barrier layer to permeation. Systemic toxicity following dermal exposure to environmental chemicals and use of skin as a portal for systemic administration of drugs have led to extensive investigations of the inward flux of xenobiotics applied to the outer surface of skin. Those investigations mainly utilized in vitro experimental systems that were limited by the absence of normal physiologic functions. The objective of the present research was to investigate an in vivo skin permeation model system thatmore » was sensitive to perturbations of skin capillary physiology and stratum corneum. A [open quotes]fuzzy[close quotes] rat model system was devised that employed outward cutaneous migration of a systemically administered permeation probe, isoflurane. Specially devised, transdermal vapor collection devices were used to capture the outward flux of isoflurane through the skin. Isoflurane flux measurements, coupled with blood isoflurane concentrations, were used to calculate cutaneous permeability coefficients (K[sub p]) of isolflurane, as an index of permeation, under various conditions of normal or perturbed cutaneous physiologic states. Physiologic perturbations were performed to test the sensitivity of the model system to detect effects of minoxidil-mediated vasodilation, phenylephrine-mediated vasoconstriction, and leukotriene D[sub 4]-mediated increased capillary permeability on the outward flux of isoflurane. Tape stripping and topical ether-ethanol application produced either physical removal or chemical disruption of the stratum corneum, respectively. Minoxidil, leukotriene D[sub 4], tape stripping of stratum corneum, and topical ether-ethanol experiments produced statistically significant increases (52 to 193%) in the K[sub p's], while phenylephrine had no significant effect on isoflurane permeation.« less

Comparison between different interdental stripping methods and evaluation of abrasive strips: SEM analysis.

PubMed

Grippaudo, Cristina; Cancellieri, Daniela; Grecolini, Maria E; Deli, Roberto

2010-01-01

The aim of this study was to evaluate the morphological effects and the surface irregularities produced by different methods of mechanical stripping (abrasive strips and burs) and chemical stripping (37% orthophosphoric acid) and the surface changes following the finishing procedures (polishing strips) or the subsequent application of sealants, in order to establish the right stripping method that can guarantee the smoothest surface. We have also analysed the level of wear on the different abrasive strips employed, according to their structure. 160 proximal surfaces of 80 sound molar teeth extracted for orthodontic and periodontal reasons, were divided into: 1 control group with non-treated enamel proximal surfaces and 5 different groups according to the stripping method used, were observed with scanning electron microscopy (SEM). Each one of the 5 treated groups was also divided into 3 different subgroups according to the finishing procedures or the subsequent application of sealants. The finishing stage following the manual reduction proves to be fundamental in reducing the number and depth of grooves created by the stripping. After the air rotor stripping method, the use of sealants is advised in order to obtain a smoother surface. The analysis of the combinations of mechanical and chemical stripping showed unsatisfactory results. Concerning the wear of the strips, we have highlighted a different abrasion degree for the different types of strips analysed with SEM. The enamel damages are limited only if the finishing procedure is applied, independently of the type of abrasive strip employed. It would be advisable, though clinically seldom possible, the use of sealants after the air rotor stripping technique. Copyright © 2010 Società Italiana di Ortodonzia SIDO. Published by Elsevier Srl. All rights reserved.

Performance of Flow and Heat Transfer in a Hot-Dip Round Coreless Galvanizing Bath

NASA Astrophysics Data System (ADS)

Yue, Qiang; Zhang, Chengbo; Xu, Yong; Zhou, Li; Kong, Hui; Wang, Jia

2017-04-01

Flow field in a coreless hot-dip galvanizing pot was investigated through a water modeling experiment. The corresponding velocity vector was measured using an acoustic Doppler velocimeter. The flow field of molten zinc in the bath was also analyzed. Steel strip velocities from 1.7 to 2.7 m/s were adopted to determine the effect of steel strip velocity on the molten zinc flow in the bath. A large vortex filled the space at the right side of the sink roll, under linear speed from 1.0 to 2.7 m/s and width from 1.0 to 1.3 m of the steel strip, because of the effects of wall and shear stress. The results of the water modeling experiment were compared with those of numerical simulations. In the simulation, Maxwell equations were solved using finite element method to obtain magnetic flux density, electromagnetic force, and Joule heating. The Joule heating rate reached the maximum and minimum values near the side wall and at the core of the bath, respectively, because of the effect of skin and proximity. In an industrial-sized model, the molten zinc flow and temperature fields driven by electromagnetic force and Joule heating in the inductor of a coreless galvanizing bath were numerically simulated. The results indicated that the direction of electromagnetic force concentrated at the center of the galvanizing pot horizontal planes and exerted a pinch effect on molten zinc. Consequently, molten zinc in the pot was stirred by electromagnetic force. Under molten zinc flow and electromagnetic force stirring, the temperature of the molten zinc became homogeneous throughout the bath. This study provides a basis for optimizing electromagnetic fields in coreless induction pot and fine-tuning the design of steel strip parameters.

[Response of water yield function of ecosystem to land use change in Nansi Lake Basin based on CLUE-S model and InVEST model .

PubMed

Guo, Hong Wei; Sun, Xiao Yin; Lian, Li Shu; Zhang, Da Zhi; Xu, Yan

2016-09-01

Land use change has an important role in hydrological processes and utilization of water resources, and is the main driving force of water yield function of ecosystem. This paper analyzed the change of land use from 1990 to 2013 in Nansi Lake Basin, Shandong Province. The future land use in 2030 was also predicted and simulated by CLUE-S model. Based on land use scenarios, we analyzed the influence of land use change on ecosystem function of water yield in nearly 25 years through InVEST water yield model and spatial mapping. The results showed that the area of construction land increased by 3.5% in 2013 because of burgeoning urbanization process, but farmland area decreased by 2.4% which was conversed to construction land mostly. The simulated result of InVEST model suggested that water yield level of whole basin decreased firstly and increased subsequently during last 25 years and peaked at 232.1 mm in 2013. The construction land area would increase by 6.7% in 2030 based on the land use scenarios of fast urbanization, which would lead to a remarkable growth for water yield and risk of flowing flooding. However, the water yield level of whole basin would decrease by 1.2 % in 2013 if 300 meter-wide forest buffer strips around Nansi Lake were built up.

Pharmacological and histological examinations of regional differences of guinea-pig lung: a role of pleural surface smooth muscle in lung strip contraction.

PubMed Central

Wong, W. S.; Bloomquist, S. L.; Bendele, A. M.; Fleisch, J. H.

1992-01-01

1. Parenchymal lung strip preparations have been widely used as an in vitro model of peripheral airway smooth muscle. The present study examined functional responses of 4 consecutive guinea-pig lung parenchymal strips isolated from the central region (segment 1) to the distal edge (segment 4) of the lower lung lobe. The middle two segments were designated as segments 2 and 3. 2. Lung segments 1 and 4 exhibited significantly greater contraction than the other 2 segments to KCl when responses were expressed as mg force per mg tissue weight. Contractile responses to bronchospastic agents including histamine, carbachol, endothelin-1, leukotrienes (LT) B4 and D4, and the thromboxane A2-mimetic U46619 demonstrated no significant difference in EC50 values among the 4 lung segments. 3. Contractile responses of segments 1 and 4 to antigen-challenge (ovalbumin), ionophore A23187 and substance P were significantly greater than the other 2 segments with respect to either sensitivity or maximum responsiveness. 4. U46619-induced contractions of the 4 lung segments were relaxed in similar manner by papaverine and theophylline up to 100%, salbutamol up to 80%, and sodium nitroprusside by only 20%. In contrast, sodium nitroprusside markedly reversed U46619-induced contraction of pulmonary arterial rings and bronchial rings. 5. Histological studies identified 2-4 layers of smooth muscle cells underlying the lung pleural surface. Mast cells were prominent in this area. Moreover, morphometric studies showed that segment 4 possessed the least amount of smooth muscle structures from bronchial/bronchiolar wall and vasculatures as compared to the other 3 segments, and a significant difference in this respect was evident between segment 1 and segment 4.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 Figure 6 PMID:1378341

Analysis of capillary drainage from a flat solid strip

NASA Astrophysics Data System (ADS)

Ramé, Enrique; Zimmerli, Gregory A.

2014-06-01

A long and narrow solid strip coated with a thin liquid layer is used as a model of a generic fluid mass probe in a spacecraft propellant tank just after a small thruster firing. The drainage dynamics of the initial coating layer into the settled bulk fluid affects the interpretation of probe measurements as the sensors' signal depends strongly on whether a sensor is in contact with vapor or with liquid. We analyze the drainage under various conditions of zero-gravity (i.e., capillary drainage) and with gravity aligned with the strip length, corresponding to the thruster acceleration. Long-time analytical solutions are found for zero and non-zero gravity. In the case with gravity, an approximate solution is found using matched asymptotics. Estimates show that a thrust of 10-3g0 significantly reduces drainage times.

Geometry and Mechanics in the Opening of Chiral Seed Pods

NASA Astrophysics Data System (ADS)

Armon, Shahaf; Efrati, Efi; Kupferman, Raz; Sharon, Eran

2011-09-01

We studied the mechanical process of seed pods opening in Bauhinia variegate and found a chirality-creating mechanism, which turns an initially flat pod valve into a helix. We studied configurations of strips cut from pod valve tissue and from composite elastic materials that mimic its structure. The experiments reveal various helical configurations with sharp morphological transitions between them. Using the mathematical framework of “incompatible elasticity,” we modeled the pod as a thin strip with a flat intrinsic metric and a saddle-like intrinsic curvature. Our theoretical analysis quantitatively predicts all observed configurations, thus linking the pod’s microscopic structure and macroscopic conformation. We suggest that this type of incompatible strip is likely to play a role in the self-assembly of chiral macromolecules and could be used for the engineering of synthetic self-shaping devices.

Some New Problems on Shells and Thin Structures

NASA Technical Reports Server (NTRS)

Vlasov, V. S.

1949-01-01

Cylindrical shells of arbitrary section, reinforced by longitudinal and transverse members (stringers and ribs) are considered by us, for a sufficiently close spacing of the ribs, as in our previously published papers (references 1 end 2), as thin-walled orthotropic spatial systems at the cross-sections of which only axial (normal and shearing) forces can arise. The longitudinal bending and twisting moments, due to their weak effect on the stress state of the shell, are taken equal to zero. Along the longitudinal sections of the shell there may arise transverse forces in addition to the normal d shearing forces. Under the so-called static assumptions there is taken for the computation model of the shell a thin-walled spatial system consisting along its length (along a generator) of an infinite number of elementary strips capable of bending. Each of these strips is likened to a curved rod operating in each of its sections not only in tension (compression)but also in transverse bending and shear. The interaction between two adjoining transverse strips in the shell expresses itself in the transmission from one strip to the other of only the normal and shearing stresses. The static structure of the computation model here described is shown in figure 1, where the connections through which the normal and shearing stresses transmitted from one transverse strip to smother are indicated schematically by the rods located in the middle surface of the shell. In addition to the static hypothesis we introduce also geometric hypotheses. According to the latter the elongational deformations of the shell along lines parallel to the generator of its middle surface and the shear deformations in the middle surface, as ma+gitudes having . little effect on the state of the fundamental internal forces of the shell, are taken equal to zero. The deformations of the shell in our computational model are such that in the first place the lines of this surface perpendicular to the generator are inextensible at each point end in the second place the angles between the lines of principal curvature (the coordinate lines) which are straight before the deformation remain straight after the deformation.

Reinforcement of osteosynthesis screws with brushite cement.

PubMed

Van Landuyt, P; Peter, B; Beluze, L; Lemaître, J

1999-08-01

The fixation of osteosynthesis screws remains a severe problem for fracture repair among osteoporotic patients. Polymethyl-methacrylate (PMMA) is routinely used to improve screw fixation, but this material has well-known drawbacks such as monomer toxicity, exothermic polymerization, and nonresorbability. Calcium phosphate cements have been developed for several years. Among these new bone substitution materials, brushite cements have the advantage of being injectable and resorbable. The aim of this study is to assess the reinforcement of osteosynthesis screws with brushite cement. Polyurethane foams, whose density is close to that of cancellous bone, were used as bone model. A hole was tapped in a foam sample, then brushite cement was injected. Trabecular osteosynthesis screws were inserted. After 24 h of aging in water, the stripping force was measured by a pull-out test. Screws (4.0 and 6.5 mm diameter) and two foam densities (0.14 and 0.28 g/cm3) were compared. Cements with varying solid/liquid ratios and xanthan contents were used in order to obtain the best screw reinforcement. During the pull-out test, the stripping force first increases to a maximum, then drops to a steady-state value until complete screw extraction. Both maximum force and plateau value increase drastically in the presence of cement. The highest stripping force is observed for 6.5-mm screws reinforced with cement in low-density foams. In this case, the stripping force is multiplied by 3.3 in the presence of cement. In a second experiment, cements with solid/liquid ratio ranging from 2.0 to 3.5 g/mL were used with 6.5-mm diameter screws. In some compositions, xanthan was added to improve injectability. The best results were obtained with 2.5 g/mL cement containing xanthan and with 3.0 g/mL cements without xanthan. A 0.9-kN maximal stripping force was observed with nonreinforced screws, while 1.9 kN was reached with reinforced screws. These first results are very promising regarding screw reinforcement with brushite cement. However, the polyurethane foam model presents noninterconnected porosity and physiological liquid was not modelized.

Guidelines for the application of removeable rumble strips

DOT National Transportation Integrated Search

2006-08-01

This work was initiated to assess the viability of removable rumble strips as replacements for asphalt rumble strips, particularly in short term highway work zones. The two rumble strips tested were the Orange Rumble Strip from Advanced Traffic Marki...

Microplasma generator and methods therefor

DOEpatents

Hopwood, Jeffrey A

2015-04-14

A low-temperature, atmospheric-pressure microplasma generator comprises at least one strip of metal on a dielectric substrate. A first end of the strip is connected to a ground plane and the second end of the strip is adjacent to a grounded electrode, with a gap being defined between the second end of the strip and the grounded electrode. High frequency power is supplied to the strip. The frequency is selected so that the length of the strip is an odd integer multiple of 1/4 of the wavelength traveling on the strip. A microplasma forms in the gap between the second end of the strip and the grounded electrode due to electric fields in that region. A microplasma generator array comprises a plurality of strongly-coupled resonant strips in close proximity to one another. At least one of the strips has an input for high-frequency electrical power. The remaining strips resonate due to coupling from the at least one powered strip. The array can provide a continuous line or ring of plasma. The microplasma generator can be used to alter the surface of a substrate, such as by adding material (deposition), removal of material (etching), or modifying surface chemistry.

Material properties of components in human carotid atherosclerotic plaques: a uniaxial extension study.

PubMed

Teng, Zhongzhao; Zhang, Yongxue; Huang, Yuan; Feng, Jiaxuan; Yuan, Jianmin; Lu, Qingsheng; Sutcliffe, Michael P F; Brown, Adam J; Jing, Zaiping; Gillard, Jonathan H

2014-12-01

Computational modelling to calculate the mechanical loading within atherosclerotic plaques has been shown to be complementary to defining anatomical plaque features in determining plaque vulnerability. However, its application has been partially impeded by the lack of comprehensive knowledge about the mechanical properties of various tissues within the plaque. Twenty-one human carotid plaques were collected from endarterectomy. The plaque was cut into rings, and different type of atherosclerotic tissues, including media, fibrous cap (FC), lipid and intraplaque haemorrhage/thrombus (IPH/T) was dissected for uniaxial extension testing. In total, 65 media strips from 17 samples, 59 FC strips from 14 samples, 38 lipid strips from 11 samples, and 21 IPH/T strips from 11 samples were tested successfully. A modified Mooney-Rivlin strain energy density function was used to characterize the stretch-stress relationship. The stiffnesses of media and FC are comparable, as are lipid and IPH/T. However, both media and FC are stiffer than either lipid or IPH/T. The median values of incremental Young's modulus of media, FC, lipid and IPH/T at λ=1 are 290.1, 244.5, 104.4, 52.9, respectively; they increase to 1019.5, 817.4, 220.7 and 176.9 at λ=1.1; and 4302.7, 3335.0, 533.4 and 268.8 at λ=1.15 (unit, kPa; λ, stretch ratio). The material constants of each tissue type are suggested to be: media, c1=0.138kPa, D1=3.833kPa and D2=18.803; FC, c1=0.186kPa, D1=5.769kPa and D2=18.219; lipid, c1=0.046kPa, D1=4.885kPa and D2=5.426; and IPH/T, c1=0.212kPa, D1=4.260kPa and D2=5.312. It is concluded that all soft atherosclerotic tissues are non-linear, and both media and FC are stiffer than either lipid or IPH/T. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Control of surface thermal scratch of strip in tandem cold rolling

NASA Astrophysics Data System (ADS)

Chen, Jinshan; Li, Changsheng

2014-07-01

The thermal scratch seriously affects the surface quality of the cold rolled stainless steel strip. Some researchers have carried out qualitative and theoretical studies in this field. However, there is currently a lack of research on effective forecast and control of thermal scratch defects in practical production, especially in tandem cold rolling. In order to establish precise mathematical model of oil film thickness in deformation zone, the lubrication in cold rolling process of SUS410L stainless steel strip is studied, and major factors affecting oil film thickness are also analyzed. According to the principle of statistics, mathematical model of critical oil film thickness in deformation zone for thermal scratch is built, with fitting and regression analytical method, and then based on temperature comparison method, the criterion for deciding thermal scratch defects is put forward. Storing and calling data through SQL Server 2010, a software on thermal scratch defects control is developed through Microsoft Visual Studio 2008 by MFC technique for stainless steel in tandem cold rolling, and then it is put into practical production. Statistics indicate that the hit rate of thermal scratch is as high as 92.38%, and the occurrence rate of thermal scratch is decreased by 89.13%. Owing to the application of the software, the rolling speed is increased by approximately 9.3%. The software developed provides an effective solution to the problem of thermal scratch defects in tandem cold rolling, and helps to promote products surface quality of stainless steel strips in practical production.

Ordering of two-dimensional crystals confined in strips of finite width

NASA Astrophysics Data System (ADS)

Ricci, A.; Nielaba, P.; Sengupta, S.; Binder, K.

2007-01-01

Monte Carlo simulations are used to study the effect of confinement on a crystal of point particles interacting with an inverse power law potential ∝r-12 in d=2 dimensions. This system can describe colloidal particles at the air-water interface, a model system for experimental study of two-dimensional melting. It is shown that the state of the system (a strip of width D ) depends very sensitively on the precise boundary conditions at the two “walls” providing the confinement. If one uses a corrugated boundary commensurate with the order of the bulk triangular crystalline structure, both orientational order and positional order is enhanced, and such surface-induced order persists near the boundaries also at temperatures where the system in the bulk is in its fluid state. However, using smooth repulsive boundaries as walls providing the confinement, only the orientational order is enhanced, but positional (quasi-)long range order is destroyed: The mean-square displacement of two particles n lattice parameters apart in the y direction along the walls then crosses over from the logarithmic increase (characteristic for d=2 ) to a linear increase with n (characteristic for d=1 ). The strip then exhibits a vanishing shear modulus. These results are interpreted in terms of a phenomenological harmonic theory. Also the effect of incommensurability of the strip width D with the triangular lattice structure is discussed, and a comparison with surface effects on phase transitions in simple Ising and XY models is made.

Characteristics of laminates with delamination control strips

NASA Technical Reports Server (NTRS)

Sun, C. T.; Goering, J. C.; Alper, J. M.; Gause, L. W.

1992-01-01

Tough resin is needed to resist delamination crack propagation. However, modulus often has to be compromised because it is difficult to retain both high modulus and toughness in a matrix material. A potential solution is to use a hybrid system in which tough resin strips are included within a conventional matrix composite. By adjusting the spacing of the tough resin strips, maximum delamination size can be controlled. Experimental results for impact damage and subsequent damage propagation in laminates containing tough resin strips are reported. Plain adhesive strips and fiber-reinforced tough resin composite strips were used in constructing the hybrid laminates. Test results indicated that size of delamination inflicted by impact was confined between the tough resin strips. As a result, significantly increased residual compressive strength was obtained. Impacted laminates containing tough resin strips were also fatigue tested. It was found that these strips reduced the growth of the impact damage area relative to the growth seen in coupons with no tough resin strips. Damage growth from an open hole under tension fatigue was evaluated using both tough resin strips and glass fiber reinforced tough resin strips. Unreinforced tough resin strips retarded delamination growth from the open hole, but did not stop matrix cracks growing in the fiber direction. Fiber reinforced tough resin strips did not contain axial delamination growth from the open hole. However, they did act as crack arresters, stopping the through-the-thickness tension crack originating from the hole.

Fixture for multiple-FCC chemical stripping and plating

NASA Technical Reports Server (NTRS)

Angele, W.; Norton, W. E.

1971-01-01

For chemical stripping, lead tape applied near ends to be stripped protects insulation. Taped ends are submerged half way in stripping solution. For electroplating, both ends of FCC are stripped - top ends for electric contact, others for submersion in electroplating solution.

Modelling and investigation of partial wetting surfaces for drop dynamics using lattice Boltzmann method

NASA Astrophysics Data System (ADS)

Pravinraj, T.; Patrikar, Rajendra

2017-07-01

Partial wetting surfaces and its influence on the droplet movement of micro and nano scale being contemplated for many useful applications. The dynamics of the droplet usually analyzed with a multiphase lattice Boltzmann method (LBM). In this paper, the influence of partial wetting surface on the dynamics of droplet is systematically analyzed for various cases. Splitting of droplets due to chemical gradient of the surface is studied and analyses of splitting time for various widths of the strips for different Weber numbers are computed. With the proposed model one can tune the splitting volume and time by carefully choosing a strip width and droplet position. The droplet spreading on chemically heterogeneous surfaces shows that the spreading can be controlled not only by parameters of Weber number but also by tuning strip width ratio. The transportation of the droplet from hydrophobic surface to hydrophilic surface due to chemical gradient is simulated and analyzed using our hybrid thermodynamic-image processing technique. The results prove that with the progress of time the surface free energy decreases with increase in spreading area. Finally, the transportation of a droplet on microstructure gradient is demonstrated. The model explains the temporal behaviour of droplet during the spreading, recoiling and translation along with tracking of contact angle hysteresis phenomenon.

Thermophilic two-stage dry anaerobic digestion of model garbage with ammonia stripping.

PubMed

Yabu, Hironori; Sakai, Chikako; Fujiwara, Tomoko; Nishio, Naomichi; Nakashimada, Yutaka

2011-03-01

To avoid the inhibition of methane production by ammonia that occurs during the degradation of garbage, anaerobic digestion with prior ammonia production and subsequent stripping was investigated. In the ammonia production phase, the maximum ammonia concentration was approximately 2800 mg N/kg of total wet sludge in the range of 4 days of sludge retention time, indicating that only 43% of total nitrogen in the model garbage was converted to ammonia. The model garbage from which ammonia was produced and stripped was subjected to semi-continuous thermophilic dry anaerobic digestion over 180 days. The gas yield was in the range of 0.68 to 0.75 Nm(3)/kg volatile solid, and it decreased with the decrease of the sludge retention time. The ammonia-nitrogen concentration in the sludge was kept below 3000 mg N/kg total wet sludge. Microbial community structure analysis revealed that the phylum Firmicutes dominated in the ammonia production, but the community structure changed at different sludge retention times. In dry anaerobic digestion, the dominant bacteria shifted from the phylum Thermotogae to Firmicutes. The dominant archaeon was the genus Methanothermobacter, but the ratio of Methanosarcina increased during the process of dry anaerobic digestion. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Reynolds Number Effects at High Angles of Attack

NASA Technical Reports Server (NTRS)

Fisher, David F.; Cobleigh, Brent R.; Banks, Daniel W.; Hall, Robert M.; Wahls, Richard A.

1998-01-01

Lessons learned from comparisons between ground-based tests and flight measurements for the high-angle-of-attack programs on the F-18 High Alpha Research Vehicle (HARV), the X-29 forward-swept wing aircraft, and the X-31 enhanced fighter maneuverability aircraft are presented. On all three vehicles, Reynolds number effects were evident on the forebodies at high angles of attack. The correlation between flight and wind tunnel forebody pressure distributions for the F-18 HARV were improved by using twin longitudinal grit strips on the forebody of the wind-tunnel model. Pressure distributions obtained on the X-29 wind-tunnel model at flight Reynolds numbers showed excellent correlation with the flight data up to alpha = 50 deg. Above (alpha = 50 deg. the pressure distributions for both flight and wind tunnel became asymmetric and showed poorer agreement, possibly because of the different surface finish of the model and aircraft. The detrimental effect of a very sharp nose apex was demonstrated on the X-31 aircraft. Grit strips on the forebody of the X-31 reduced the randomness but increased the magnitude of the asymmetry. Nose strakes were required to reduce the forebody yawing moment asymmetries and the grit strips on the flight test noseboom improved the aircraft handling qualities.

C-Kit expression in the gallbladder of guinea pig with chronic calculous cholecystitis and the effect of Artemisia capillaris Thunb on interstitial cells of Cajal.

PubMed

Feng, Hua; Wang, Fang; Wang, Changmiao

2016-07-01

To study the c-Kit expression in the gallbladder of cholesterol lithogenic guinea pig model and the effect of Artemisia capillaris Thunb on interstitial cells of Cajal (ICCs). A total of 45 guinea pigs were randomly assigned into three groups: the control group (guinea pigs fed a standard diet, normal group); the model group (guinea pigs fed a cholesterol gallstone-inducing diet); and the Chinese medicine group (guinea pigs fed the cholesterol gallstone-inducing diet and treated with A. capillaris through intragastric administration, therapy group). Each group had 15 guinea pigs. The gallbladders of the guinea pigs were harvested after 8 weeks. C-Kit expression was detected using an immunohistochemistry staining, real-time PCR, and Western blot analyses. The effect of A. capillaris on ICCs was evaluated by muscle strip contraction experiments. C-Kit expression significantly decreased in the gallbladder of model group, but increased in the Chinese medicine group. The Contractility of guinea pig gallbladder muscle strip significantly improved in the Chinese medicine group. Our results indicated that A. capillaris improves gallbladder impairment by up-regulating c-Kit expression, and it also can improve the contractile response of in vitro guinea pig gallbladder muscle strips.

Novel fungal FAD glucose dehydrogenase derived from Aspergillus niger for glucose enzyme sensor strips.

PubMed

Sode, Koji; Loew, Noya; Ohnishi, Yosuke; Tsuruta, Hayato; Mori, Kazushige; Kojima, Katsuhiro; Tsugawa, Wakako; LaBelle, Jeffrey T; Klonoff, David C

2017-01-15

In this study, a novel fungus FAD dependent glucose dehydrogenase, derived from Aspergillus niger (AnGDH), was characterized. This enzyme's potential for the use as the enzyme for blood glucose monitor enzyme sensor strips was evaluated, especially by investigating the effect of the presence of xylose during glucose measurements. The substrate specificity of AnGDH towards glucose was investigated, and only xylose was found as a competing substrate. The specific catalytic efficiency for xylose compared to glucose was 1.8%. The specific activity of AnGDH for xylose at 5mM concentration compared to glucose was 3.5%. No other sugars were used as substrate by this enzyme. The superior substrate specificity of AnGDH was also demonstrated in the performance of enzyme sensor strips. The impact of spiking xylose in a sample with physiological glucose concentrations on the sensor signals was investigated, and it was found that enzyme sensor strips using AnGDH were not affected at all by 5mM (75mg/dL) xylose. This is the first report of an enzyme sensor strip using a fungus derived FADGDH, which did not show any positive bias at a therapeutic level xylose concentration on the signal for a glucose sample. This clearly indicates the superiority of AnGDH over other conventionally used fungi derived FADGDHs in the application for SMBG sensor strips. The negligible activity of AnGDH towards xylose was also explained on the basis of a 3D structural model, which was compared to the 3D structures of A. flavus derived FADGDH and of two glucose oxidases. Copyright © 2016 Elsevier B.V. All rights reserved.

Brain-Derived Neurotrophic Factor Contributes to Colonic Hypermotility in a Chronic Stress Rat Model.

PubMed

Quan, Xiaojing; Luo, Hesheng; Fan, Han; Tang, Qincai; Chen, Wei; Cui, Ning; Yu, Guang; Xia, Hong

2015-08-01

Brain-derived neurotrophic factor (BDNF) has prokinetic effects on gut motility and is increased in the colonic mucosa of irritable bowel syndrome. We aimed to investigate the possible involvement of BDNF in stress-induced colonic hypermotility. Male Wistar rats were exposed to daily 1-h water avoidance stress (WAS) or sham WAS for 10 consecutive days. The presence of BDNF and substance P (SP) in the colonic mucosa was determined using enzyme immunoassay kits. Immunohistochemistry and western blotting were performed to assess the expression of BDNF and its receptor, TrkB. The contractions of muscle strips were studied in an organ bath system. Repeated WAS increased the fecal pellet expulsion and spontaneous contractile activities of the colonic muscle strips. Both BDNF and SP in the colonic mucosa were elevated following WAS. Immunohistochemistry revealed the presence of BDNF and TrkB in the mucosa and myenteric plexus. BDNF and TrkB were both up-regulated in colon devoid of mucosa and submucosa from the stressed rats compared with the control. BDNF pretreatment caused an enhancement of the SP-induced contraction of the circular muscle (CM) strips. TrkB antibody significantly inhibited the contraction of the colonic muscle strips and attenuated the excitatory effects of SP on contractions of the CM strips. Repeated WAS increased the contractile activities of the CM strips induced by SP after BDNF pretreatment, and this effect was reversed by TrkB antibody. The colonic hypermotility induced by repeated WAS may be associated with the increased expression of endogenous BDNF and TrkB. BDNF may have potential clinical therapeutic use in modulating gut motility.

Characterization of energy response for photon-counting detectors using x-ray fluorescence

PubMed Central

Ding, Huanjun; Cho, Hyo-Min; Barber, William C.; Iwanczyk, Jan S.; Molloi, Sabee

2014-01-01

Purpose: To investigate the feasibility of characterizing a Si strip photon-counting detector using x-ray fluorescence. Methods: X-ray fluorescence was generated by using a pencil beam from a tungsten anode x-ray tube with 2 mm Al filtration. Spectra were acquired at 90° from the primary beam direction with an energy-resolved photon-counting detector based on an edge illuminated Si strip detector. The distances from the source to target and the target to detector were approximately 19 and 11 cm, respectively. Four different materials, containing silver (Ag), iodine (I), barium (Ba), and gadolinium (Gd), were placed in small plastic containers with a diameter of approximately 0.7 cm for x-ray fluorescence measurements. Linear regression analysis was performed to derive the gain and offset values for the correlation between the measured fluorescence peak center and the known fluorescence energies. The energy resolutions and charge-sharing fractions were also obtained from analytical fittings of the recorded fluorescence spectra. An analytical model, which employed four parameters that can be determined from the fluorescence calibration, was used to estimate the detector response function. Results: Strong fluorescence signals of all four target materials were recorded with the investigated geometry for the Si strip detector. The average gain and offset of all pixels for detector energy calibration were determined to be 6.95 mV/keV and −66.33 mV, respectively. The detector’s energy resolution remained at approximately 2.7 keV for low energies, and increased slightly at 45 keV. The average charge-sharing fraction was estimated to be 36% within the investigated energy range of 20–45 keV. The simulated detector output based on the proposed response function agreed well with the experimental measurement. Conclusions: The performance of a spectral imaging system using energy-resolved photon-counting detectors is very dependent on the energy calibration of the detector. The proposed x-ray fluorescence technique offers an accurate and efficient way to calibrate the energy response of a photon-counting detector. PMID:25471962

Investigation of Meniscus Region Behavior and Oscillation Mark Formation in Steel Continuous Casting Using a Transient Thermo-Fluid Model

NASA Astrophysics Data System (ADS)

Blaes, Carly

In the continuous casting of steel, many complex phenomena in the meniscus region of the mold are responsible for the formation of oscillation marks. Oscillation marks are depressions found around the perimeter of continuously cast steel slabs, which if too large can lead to cracking in steel slabs. Therefore, knowledge on how to minimize the size of oscillation marks is very valuable. A computational model was created of the meniscus region, which includes transient multiphase fluid flow of slag and steel, with low-Reynolds turbulence, heat transfer in the mold, slag, and steel, steel shell solidification, mold oscillation, and temperature-dependent properties. This model was first validated using previous experimental and plant data. The model was then used to study the impact of varying casting parameters, including oscillation frequency, stroke, modification ratio, casting speed, molten steel level fluctuations, and temperature-dependent slag properties and surface tension on the oscillation mark shape, and other aspects of thermal-flow behavior during each oscillation cycle, including heat flux profile, slag consumption and mold friction. The first half of oscillation marks were formed during negative strip time as the slag rim pushed molten steel away from the mold wall and that the second half of oscillation marks were formed during positive strip time as the molten steel is drawn near the mold wall due to the upstroke of the mold. Oscillation mark depth was found to decrease with increasing frequency, modification ratio, casting speed, and slag viscosity, while oscillation mark depth was found to increase with increasing stroke. Oscillation mark width was only found to increase due to increases in pitch, which can be contributed to decreasing frequency or increasing casting speed. While many observations were made in this study, in general, oscillation mark depth and total slag consumption increase with increasing negative strip time, while the average heat flux and average mold friction decrease with increasing negative strip time.

Test and Analysis Correlation for a Y-Joint Specimen for a Composite Cryotank

NASA Technical Reports Server (NTRS)

Mason, Brian H.; Sleight, David W.; Grenoble, Ray

2015-01-01

The Composite Cryotank Technology Demonstration (CCTD) project under NASA's Game Changing Development Program (GCDP) developed space technologies using advanced composite materials. Under CCTD, NASA funded the Boeing Company to design and test a number of element-level joint specimens as a precursor to a 2.4-m diameter composite cryotank. Preliminary analyses indicated that the y-joint in the cryotank had low margins of safety; hence the y-joint was considered to be a critical design region. The y-joint design includes a softening strip wedge to reduce localized shear stresses at the skirt/dome interface. In this paper, NASA-developed analytical models will be correlated with the experimental results of a series of positive-peel y-joint specimens from Boeing tests. Initial analytical models over-predicted the experimental strain gage readings in the far-field region by approximately 10%. The over-prediction was attributed to uncertainty in the elastic properties of the laminate and a mismatch between the thermal expansion of the strain gages and the laminate. The elastic properties of the analytical model were adjusted to account for the strain gage differences. The experimental strain gages also indicated a large non-linear effect in the softening strip region that was not predicted by the analytical model. This non-linear effect was attributed to delamination initiating in the softening strip region at below 20% of the failure load for the specimen. Because the specimen was contained in a thermally insulated box during cryogenic testing to failure, delamination initiation and progression was not visualized during the test. Several possible failure initiation locations were investigated, and a most likely failure scenario was determined that correlated well with the experimental data. The most likely failure scenario corresponded to damage initiating in the softening strip and delamination extending to the grips at final failure.

Modeling the Classic Meselson and Stahl Experiment.

ERIC Educational Resources Information Center

D'Agostino, JoBeth

2001-01-01

Points out the importance of molecular models in biology and chemistry. Presents a laboratory activity on DNA. Uses different colored wax strips to represent "heavy" and "light" DNA, cesium chloride for identification of small density differences, and three different liquids with varying densities to model gradient…

Lateral Flow Assay Based on Paper-Hydrogel Hybrid Material for Sensitive Point-of-Care Detection of Dengue Virus.

PubMed

Choi, Jane Ru; Yong, Kar Wey; Tang, Ruihua; Gong, Yan; Wen, Ting; Yang, Hui; Li, Ang; Chia, Yook Chin; Pingguan-Murphy, Belinda; Xu, Feng

2017-01-01

Paper-based devices have been broadly used for the point-of-care detection of dengue viral nucleic acids due to their simplicity, cost-effectiveness, and readily observable colorimetric readout. However, their moderate sensitivity and functionality have limited their applications. Despite the above-mentioned advantages, paper substrates are lacking in their ability to control fluid flow, in contrast to the flow control enabled by polymer substrates (e.g., agarose) with readily tunable pore size and porosity. Herein, taking the benefits from both materials, the authors propose a strategy to create a hybrid substrate by incorporating agarose into the test strip to achieve flow control for optimal biomolecule interactions. As compared to the unmodified test strip, this strategy allows sensitive detection of targets with an approximately tenfold signal improvement. Additionally, the authors showcase the potential of functionality improvement by creating multiple test zones for semi-quantification of targets, suggesting that the number of visible test zones is directly proportional to the target concentration. The authors further demonstrate the potential of their proposed strategy for clinical assessment by applying it to their prototype sample-to-result test strip to sensitively and semi-quantitatively detect dengue viral RNA from the clinical blood samples. This proposed strategy holds significant promise for detecting various targets for diverse future applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Non-Euclidean stress-free configuration of arteries accounting for curl of axial strips sectioned from vessels.

PubMed

Takamizawa, Keiichi; Nakayama, Yasuhide

2013-11-01

It is well known that arteries are subject to residual stress. In earlier studies, the residual stress in the arterial ring relieved by a radial cut was considered in stress analysis. However, it has been found that axial strips sectioned from arteries also curled into arcs, showing that the axial residual stresses were relieved from the arterial walls. The combined relief of circumferential and axial residual stresses must be considered to accurately analyze stress and strain distributions under physiological loading conditions. In the present study, a mathematical model of a stress-free configuration of artery was proposed using Riemannian geometry. Stress analysis for arterial walls under unloaded and physiologically loaded conditions was performed using exponential strain energy functions for porcine and human common carotid arteries. In the porcine artery, the circumferential stress distribution under physiological loading became uniform compared with that without axial residual strain, whereas a gradient of axial stress distribution increased through the wall thickness. This behavior showed almost the same pattern that was observed in a recent study in which approximate analysis accounting for circumferential and axial residual strains was performed, whereas the circumferential and axial stresses increased from the inner surface to the outer surface under a physiological condition in the human common carotid artery of a two-layer model based on data of other recent studies. In both analyses, Riemannian geometry was appropriate to define the stress-free configurations of the arterial walls with both circumferential and axial residual strains.

Bird community response to filter strips in Maryland

USGS Publications Warehouse

Blank, P.J.; Dively, G.P.; Gill, D.E.; Rewa, C.A.

2011-01-01

Filter strips are strips of herbaceous vegetation planted along agricultural field margins adjacent to streams or wetlands and are designed to intercept sediment, nutrients, and agrichemicals. Roughly 16,000 ha of filter strips have been established in Maryland through the United States Department of Agriculture's Conservation Reserve Enhancement Program. Filter strips often represent the only uncultivated herbaceous areas on farmland in Maryland and therefore may be important habitat for early-successional bird species. Most filter strips in Maryland are planted to either native warm-season grasses or cool-season grasses and range in width from 10.7 m to 91.4 m. From 2004 to 2007 we studied the breeding and wintering bird communities in filter strips adjacent to wooded edges and non-buffered field edges and the effect that grass type and width of filter strips had on bird community composition. We used 5 bird community metrics (total bird density, species richness, scrub-shrub bird density, grassland bird density, and total avian conservation value), species-specific densities, nest densities, and nest survival estimates to assess the habitat value of filter strips for birds. Breeding and wintering bird community metrics were greater in filter strips than in non-buffered field edges but did not differ between cool-season and warm-season grass filter strips. Most breeding bird community metrics were negatively related to the percent cover of orchardgrass (Dactylis glomerata) in ???1 yr. Breeding bird density was greater in narrow (60 m) filter strips. Our results suggest that narrow filter strips adjacent to wooded edges can provide habitat for many bird species but that wide filter strips provide better habitat for grassland birds, particularly obligate grassland species. If bird conservation is an objective, avoid planting orchardgrass in filter strips and reduce or eliminate orchardgrass from filter strips through management practices. Copyright ?? 2011 The Wildlife Society.

26 CFR 1.1286-2 - Stripped inflation-protected debt instruments.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 11 2013-04-01 2013-04-01 false Stripped inflation-protected debt instruments... Losses § 1.1286-2 Stripped inflation-protected debt instruments. Stripped inflation-protected debt instruments. If a Treasury Inflation-Protected Security is stripped under the Department of the Treasury's...

26 CFR 1.1286-2 - Stripped inflation-protected debt instruments.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 11 2014-04-01 2014-04-01 false Stripped inflation-protected debt instruments... Losses § 1.1286-2 Stripped inflation-protected debt instruments. Stripped inflation-protected debt instruments. If a Treasury Inflation-Protected Security is stripped under the Department of the Treasury's...

LEO high voltage solar array arcing response model, continuation 5

NASA Technical Reports Server (NTRS)

Metz, Roger N.

1989-01-01

The modeling of the Debye Approximation electron sheaths in the edge and strip geometries was completed. Electrostatic potentials in these sheaths were compared to NASCAP/LEO solutions for similar geometries. Velocity fields, charge densities and particle fluxes to the biased surfaces were calculated for all cases. The major conclusion to be drawn from the comparisons of our Debye Approximation calculations with NASCAP-LEO output is that, where comparable biased structures can be defined and sufficient resolution obtained, these results are in general agreement. Numerical models for the Child-Langmuir, high-voltage electron sheaths in the edge and strip geometries were constructed. Electrostatic potentials were calculated for several cases in each of both geometries. Velocity fields and particle fluxes were calculated. The self-consistent solution process was carried through one cycle and output electrostatic potentials compared to NASCAP-type input potentials.

26 CFR 1.1286-2 - Stripped inflation-indexed debt instruments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Stripped inflation-indexed debt instruments. 1....1286-2 Stripped inflation-indexed debt instruments. Stripped inflation-indexed debt instruments. If a Treasury Inflation-Indexed Security is stripped under the Department of the Treasury's Separate Trading of...

Lowering Cost Share May Improve Rates of Home Glucose Monitoring Among Patients with Diabetes Using Insulin.

PubMed

Xie, Yiqiong; Agiro, Abiy; Bowman, Kevin; DeVries, Andrea

2017-08-01

Not much is known about the extent to which lower cost share for blood glucose strips is associated with persistent filling. To evaluate the relationship between cost sharing for blood glucose testing strips and continued use of testing strips. This is a retrospective observational study using medical and pharmacy claims data integrated with laboratory hemoglobin A1c (A1c) values for patients using insulin and blood glucose testing strips. Diabetic patients using insulin who had at least 1 fill of blood glucose testing strips between 2010 and 2012 were included. Patients were divided into a low cost-share group (out-of-pocket cost percentage of total testing strip costs over a 1-year period from the initial fill < 20%; n = 3,575) and a high cost-share group (out-of-pocket cost percentage ≥ 20%; n = 3,580). We compared the likelihood of continued testing strip fills after the initial fill between the 2 groups by using modified Poisson regression models. Patients with low cost share had higher rates of continued testing strip fills compared with those with high cost share (89% vs. 82%, P < 0.001). Lower cost share was associated with greater probability of continued fills (adjusted risk ratio [aRR] = 1.05, 95% CI = 1.03-1.07, P < 0.001). Other patient characteristics associated with continued fills included type 1 diabetes diagnosis, types of insulin regimens, and health insurance plan type. In a subset analysis of patients whose A1c values at baseline were above the target level (8%) set by the National Committee for Quality Assurance guidelines, we saw a slight increase in magnitude of relationship between cost share and continued fills (RR = 1.06, 95% CI = 1.03-1.10, P < 0.01). There was a statistically significant association between cost share for testing strips and continued blood glucose self-monitoring. Among patients not achieving A1c control at baseline, there was an increase in the magnitude of relationship. Lowering cost share for testing strips can remove a barrier to persistence in diabetes self-management. Funding for this study was provided by Anthem, which had no role in the study design, data interpretation, or preparation or review of the manuscript. The decision to publish was strictly that of the authors. Xie, Agiro, and DeVries are employees of HealthCore, a wholly owned subsidiary of Anthem. Bowman is an employee of Anthem. Study concept and design were contributed by all the authors. Xie took the lead in data collection, along with Agiro, and data interpretation was performed by all the authors. The manuscript was written by Xie and Agiro, along with DeVries, and revised by Xie, Agiro, and Devries, along with Bowman.

Bismuth-based electrochemical stripping analysis

DOEpatents

Wang, Joseph

2004-01-27

Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

Time-dependent alteration in cromakalim-induced relaxation of corpus cavernosum from streptozocin-induced diabetic rats.

PubMed

Ghasemi, Mehdi; Sadeghipour, Hamed; Asadi, Shahrzad; Dehpour, Ahmad Reza

2007-09-01

The purpose of the present study was to investigate the relaxant responses to the ATP-sensitive potassium (K(ATP)) channel opener cromakalim in corpus cavernosum strips from 1-, 2-, 4-, 6-, and 8-week streptozocin-induced diabetic rats. Cromakalim (1 nM-0.1 mM) produced concentration-dependent relaxation in phenylephrine (7.5 microM)-precontracted isolated rat corporal strips. Compared with age-matched control animals, a significant enhancement in cromakalim-induced relaxation of corpus cavernosum was observed in 2-week diabetic animals, whereas the relaxant responses to cromakalim were decreased in 6-and 8-week diabetic animals. However, the cromakalim-induced relaxation was not altered in either 1-week or 4-week rat corporal strips in comparison with corresponding age-matched non-diabetic groups. Preincubation with the K(ATP) channel blocker glibenclamide (10 microM) significantly inhibited the cromakalim-induced relaxation in both non-diabetic and diabetic rat corpus cavernosum, but neither the voltage-dependent K(+) channel (K(V)) antagonist 4-aminopyridine (1 mM) nor the calcium-activated K(+) channel (K(Ca)) antagonist charybdotoxin (0.1 microM) had significant effect on cromakalim-induced relaxation in both control and diabetic rat corporal strips. Relaxation responses to the nitric oxide donor sodium nitroprusside (1 nM-0.1 mM) in diabetic rat corpus cavernosum were similar to that of age-matched controls. These data demonstrated that the relaxant responses to cromakalim were altered in diabetic cavernosal strips in a time dependent manner, suggesting that the period of diabetes mellitus may play a key role in the K(ATP) channels function in rat corpus cavernosum.

Stratum corneum integrity as a predictor for peristomal skin problems in ostomates.

PubMed

Nybaek, H; Lophagen, S; Karlsmark, T; Bang Knudsen, D; Jemec, G B E

2010-02-01

Peristomal skin problems are common, most often the result is disruption of the skin barrier and this may account for more than one in three visits to ostomy nurses. Therefore a specific assessment of individual risk factors relating to the skin barrier function would be of great interest. Skin barrier integrity in ostomy patients with peristomal skin problems (PSP) was compared with that of ostomy patients with normal skin (controls) using transepidermal water loss (TEWL). Mechanical barrier disruption was determined by a tape stripping test and chemical barrier disruption [sodium lauryl sulphate (SLS) 0.25%]. Patients and controls had a highly significant increase in TEWL value in the peristomal area compared with nonperistomal contralateral abdominal skin (P < 0.0001 for both groups). The skin barrier of normal-looking contralateral skin of ostomates was found to be borderline impaired in patients with PSP compared with those without. A linear association was seen between the number of tape strips removed and TEWL for both cases and controls. Tape stripping suggested that patients with PSP had less resilient skin (P = 0.002). A significant difference in TEWL value between cases and controls was also seen for the SLS patch test on the dorsal skin (P = 0.02). Successive tape stripping, a situation analogous to the normal use of a pouching system, caused a higher degree of barrier damage more rapidly in patients with PSP, indicating an impaired mechanical quality of the barrier. The SLS exposure test suggested a generally increased susceptibility to irritant dermatitis as assessed by TEWL. Our findings suggest tape stripping and SLS testing may have a role as predictive tests to identify patients at risk of PSP.

Long-term subdural strip electrocorticographic monitoring of ictal déjà vu.

PubMed

Weinand, M E; Hermann, B; Wyler, A R; Carter, L P; Oommen, K J; Labiner, D; Ahern, G; Herring, A

1994-01-01

We report a series of 8 patients with ictal déjà vu. Subdural strip electrocorticographic (ECoG) monitoring localized the ictal epileptogenic focus as follows: right (n = 6) and left (n = 2) mesiotemporal lobe. In all 8 patients, the left hemisphere was dominant for language function based on intracarotid amytal testing. In 6 right-handed patients, ictal déjà vu was associated with a right temporal lobe focus. However, in the 2 left-handed patients, the ictal focus was left temporal lobe. Although ictal déjà vu localizes the epileptic focus to temporal lobe, this experimental phenomenon appears to lateralize to the hemisphere nondominant for handedness.

Emission FTIR analyses of thin microscopic patches of jet fuel residue deposited on heated metal surface

NASA Technical Reports Server (NTRS)

Lauer, J. L.; Vogel, P.

1984-01-01

Deposits laid down in patches on metal strips in a high pressure/high temperature fuel system simulator operated with aerated fuel at varying flow rates were analyzed by emission FTIR in terms of functional groups. Significant differences were found in the spectra and amounts of deposits derived from fuels to which small concentrations of oxygen-, nitrogen-, or sulfur-containing heterocyclics or metal naphthenates were added. The spectra of deposits generated on strips by heating fuels and air in a closed container were very different from those of the flowing fluid deposits. One such closed-container dodecane deposit on silver gave a strong surface-enhanced Raman spectrum.

STRIP1, a core component of STRIPAK complexes, is essential for normal mesoderm migration in the mouse embryo.

PubMed

Bazzi, Hisham; Soroka, Ekaterina; Alcorn, Heather L; Anderson, Kathryn V

2017-12-19

Regulated mesoderm migration is necessary for the proper morphogenesis and organ formation during embryonic development. Cell migration and its dependence on the cytoskeleton and signaling machines have been studied extensively in cultured cells; in contrast, remarkably little is known about the mechanisms that regulate mesoderm cell migration in vivo. Here, we report the identification and characterization of a mouse mutation in striatin-interacting protein 1 ( Strip1 ) that disrupts migration of the mesoderm after the gastrulation epithelial-to-mesenchymal transition (EMT). STRIP1 is a core component of the biochemically defined mammalian striatin-interacting phosphatases and kinase (STRIPAK) complexes that appear to act through regulation of protein phosphatase 2A (PP2A), but their functions in mammals in vivo have not been examined. Strip1 -null mutants arrest development at midgestation with profound disruptions in the organization of the mesoderm and its derivatives, including a complete failure of the anterior extension of axial mesoderm. Analysis of cultured mesoderm explants and mouse embryonic fibroblasts from null mutants shows that the mesoderm migration defect is correlated with decreased cell spreading, abnormal focal adhesions, changes in the organization of the actin cytoskeleton, and decreased velocity of cell migration. The results show that STRIPAK complexes are essential for cell migration and tissue morphogenesis in vivo. Copyright © 2017 the Author(s). Published by PNAS.

In-place oil shale resources of the Mahogany zone sorted by grade, overburden thickness and stripping ratio, Green River Formation, Piceance Basin, Colorado and Uinta Basin, Utah

USGS Publications Warehouse

Birdwell, Justin E.; Mercier, Tracey J.; Johnson, Ronald C.; Brownfield, Michael E.

2015-01-01

A range of geological parameters relevant to mining oil shale have been examined for the Mahogany zone of the Green River Formation in the Piceance Basin, Colorado, and Uinta Basin, Utah, using information available in the U.S. Geological Survey Oil Shale Assessment database. Basinwide discrete and cumulative distributions of resource in-place as a function of (1) oil shale grade, (2) Mahogany zone thickness, (3) overburden thickness, and (4) stripping ratio (overburden divided by zone thickness) were determined for both basins on a per-acre basis, and a resource map showing the areal distribution of these properties was generated. Estimates of how much of the Mahogany zone resource meets various combinations of these parameters were also determined. Of the 191.7 billion barrels of Mahogany zone oil in-place in the Piceance Basin, 32.3 percent (61.8 billion barrels) is associated with oil shale yielding at least 25 gallons of oil per ton (GPT) of rock processed, is covered by overburden 1,000 feet thick or less, and has a stripping ratio of less than 10. In the Uinta Basin, 14.0 percent (29.9 billion barrels) of the 214.5 billion barrels of Mahogany zone oil in-place meets the same overburden and stripping ratio criteria but only for the lower grade cutoff of 15 GPT.

Stable elastic knots with no self-contact

NASA Astrophysics Data System (ADS)

Moulton, Derek E.; Grandgeorge, Paul; Neukirch, Sébastien

2018-07-01

We study an elastic rod bent into an open trefoil knot and clamped at both ends. The question we consider is whether there are stable configurations for which there are no points of self-contact. This idea can be fairly easily replicated with a thin strip of paper, but is more difficult or even impossible with a flexible wire. We search for such configurations within the space of three tuning parameters related to the degrees of freedom in a simple experiment. Mathematically, we show, both within standard Kirchhoff theory as well within an elastic strip theory, that stable and contact-free knotted configurations can be found, and we classify the corresponding parametric regions. Numerical results are complemented with an asymptotic analysis that demonstrates the presence of knots near the doubly-covered ring. In the case of the strip model, quantitative experiments of the region of good knots are also provided to validate the theory.

Experimental, water droplet impingement data on two-dimensional airfoils, axisymmetric inlet and Boeing 737-300 engine inlet

NASA Technical Reports Server (NTRS)

Papadakis, M.; Elangovan, E.; Freund, G. A., Jr.; Breer, M. D.

1987-01-01

An experimental method has been developed to determine the droplet impingement characteristics on two- and three-dimensional bodies. The experimental results provide the essential droplet impingement data required to validate particle trajectory codes, used in aircraft icing analyses and engine inlet particle separator analyses. A body whose water droplet impingement characteristics are required is covered at strategic locations by thin strips of moisture absorbing (blotter) paper, and then exposed to an air stream containing a dyed-water spray cloud. Water droplet impingement data are extracted from the dyed blotter strips, by measuring the optical reflectance of the dye deposit on the strips, using an automated reflectometer. Impingement efficiency data obtained for a NACA 65(2)015 airfoil section, a supercritical airfoil section, and Being 737-300 and axisymmetric inlet models are presented in this paper.

Nonlinear Dynamics of a Foil Bearing Supported Rotor System: Simulation and Analysis

NASA Technical Reports Server (NTRS)

Li, Feng; Flowers, George T.

1996-01-01

Foil bearings provide noncontacting rotor support through a number of thin metal strips attached around the circumference of a stator and separated from the rotor by a fluid film. The resulting support stiffness is dominated by the characteristics of the foils and is a nonlinear function of the rotor deflection. The present study is concerned with characterizing this nonlinear effect and investigating its influence on rotordynamical behavior. A finite element model is developed for an existing bearing, the force versus deflection relation characterized, and the dynamics of a sample rotor system are studied. Some conclusions are discussed with regard to appropriate ranges of operation for such a system.

Volatile fatty acids (VFAs) production from swine manure through short-term dry anaerobic digestion and its separation from nitrogen and phosphorus resources in the digestate.

PubMed

Huang, Weiwei; Huang, Wenli; Yuan, Tian; Zhao, Ziwen; Cai, Wei; Zhang, Zhenya; Lei, Zhongfang; Feng, Chuanping

2016-03-01

The sustainability of an agricultural system depends highly upon the recycling of all useful substances from agricultural wastes. This study explored the feasibility of comprehensive utilization of C, N and P resources in swine manure (SM) through short-term dry anaerobic digestion (AD) followed by dry ammonia stripping, aiming at achieving (1) effective total volatile fatty acids (VFAs) production and separation; (2) ammonia recovery from the digestate; and (3) preservation of high P bioavailability in the solid residue for further applications. Specifically, two ammonia stripping strategies were applied and compared in this work: (I) ammonia stripping was directly performed with the digestate from dry AD of SM (i.e. dry ammonia stripping); and (II) wet ammonia stripping was conducted by using the resultant filtrate from solid-liquid separation of the mixture of digestate and added water. Results showed that dry AD of the tested SM at 55 °C, 20% TS and unadjusted initial pH (8.6) for 8 days produced relatively high concentrations of total VFAs (94.4 mg-COD/g-VS) and ammonia-N (20.0 mg/g-VS) with high potentially bioavailable P (10.6 mg/g-TS) remained in the digestate, which was considered optimal in this study. In addition, high ammonia removal efficiencies of 96.2% and 99.7% were achieved through 3 h' dry and wet stripping (at 55 °C and initial pH 11.0), respectively, while the total VFAs concentration in the digestate/filtrate remained favorably unchanged. All experimental data from the two stripping processes well fitted to the pseudo first-order kinetic model (R(2) = 0.9916-0.9997) with comparable theoretical maximum ammonia removal efficiencies (Aeq, >90%) being obtained under the tested dry and wet stripping conditions, implying that the former was more advantageous due to its much higher volumetric total ammonia-N removal rate thus much smaller reactor volume, less energy/chemicals consumption and no foaming problems. After 8 days' dry AD and 3 h' dry ammonia stripping, the separated liquid containing VFAs and the recovered ammonia were both marketable products, and the solid residues with averagely higher C/N ratios of 25.7 than those of raw SM (18.0) meanwhile maintaining a relatively high bioavailable P content of 8.1 mg/g-TS can serve as better feedstock for methane fermentation. Copyright © 2015 Elsevier Ltd. All rights reserved.

An assessment of buffer strips for improving damage tolerance

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.; Kennedy, J. M.

1981-01-01

Graphite/epoxy panels with buffer strips were tested in tension to measure their residual strength with crack-like damage. Panels were made with 45/0/-45/90(2S) and 45/0/450(2S) layups. The buffer strips were parallel to the loading directions. They were made by replacing narrow strips of the 0 deg graphite plies with strips of either 0 deg S-Glass/epoxy or Kevlar-49/epoxy on either a one for one or a two for one basis. In a third case, O deg graphite/epoxy was used as the buffer material and thin, perforated Mylar strips were placed between the 0 deg piles and the cross-plies to weaken the interfaces and thus to isolate the 0 deg plies. Some panels were made with buffer strips of different widths and spacings. The buffer strips arrested the cracks and increased the residual strengths significantly over those plain laminates without buffer strips. A shear-lag type stress analysis correctly predicted the effects of layups, buffer material, buffer strip width and spacing, and the number of plies of buffer material.

An assessment of buffer strips for improving damage tolerance of composite laminates

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.; Kennedy, J. M.

1980-01-01

Graphite/epoxy panels with buffer strips were tested in tension to measure their residual strength with crack-like damage. Panels were made with (45/0/-45/90)2S and (45/0/-45/0)2S layups. The buffer strips were parallel to the loading direction. They were made by replacing narrow strips of the 0 deg graphite plies with strips of either 0 deg S-Glass/epoxy or Kevlar-90/epoxy on either a one-for-one or a two-for-one basis. In a third case, 0 deg graphite/epoxy was used as the buffer material and thin, perforated Mylar strips were placed between the 0 deg plies and the cross-plies to weaken the interfaces and thus to isolate the 0 deg plies. Some panels were made with buffer strips of different width and spacings. The buffer strips arrested the cracks and increased the residual strengths significantly over those of plain laminates without buffer strips. A shear-lag type stress analysis correctly predicted the effects of layup, buffer material, buffer strip width and spacing, and the number of plies of buffer material

Ignition Delay Associated with a Strained Strip

NASA Technical Reports Server (NTRS)

Gerk, T. J.; Karagozian, A. R.

1996-01-01

Ignition processes associated with two adjacent fuel-oxidizer interferences bounding a strained fuel strip are explored here using single-step activation energy asymptotics. Calculations are made for constant as well as temporally decaying strain fields. There possible models of ignition are determined: one in which the two interfaces ignite independently as diffusion flames; one in which the two interfaces ignite dependently and in which ignition occurs to form a single , premixed flame at very high strain rates before ignition is completely prevented. In contrast to a single, isolated interface in which ignition can be prevented by overmatching heat production with heat convection due to strain, ignition of a strained fuel strip can also be prevented if the finite extend of fuel is diluted by oxidizer more quickly than heat production can cause a positive feedback thermal runaway. These behaviors are dependent on the relative sizes of timescales associated with species and heat diffusion, with convection due to strain, and with the chemical reaction. The result here indicate that adjacent, strained species interfaces may ignite quite differently in nature from ignition of a single, strained intrface and that their interdependence should be considered as the interfaces are brought closer together in complex strain fields. Critical strain rates leading to complete ignition delay are found to be considerably smaller for the fuel strip than those for single interfaces as the fuel strip is made thin in comparison to diffusion and chemical length scales.

Roll Casting of Aluminum Alloy Clad Strip

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

Nakamura, R.; Tsuge, H.; Haga, T.

2011-01-17

Casting of aluminum alloy three layers of clad strip was tried using the two sets of twin roll casters, and effects of the casting parameters on the cladding conditions were investigated. One twin roll caster was mounted on the other twin roll caster. Base strip was 8079 aluminum alloy and overlay strips were 6022 aluminum alloy. Effects of roll-load of upper and lower casters and melt temperature of the lower caster were investigated. When the roll-load of the upper and lower caster was large enough, the overlay strip could be solidified and be connected. The overlay strip could be connectedmore » when the melt of the overlay strip cast by the lower caster was low enough. Sound three layers of clad strip could be cast by proper conditions.« less

Lateral flow strip assay

DOEpatents

Miles, Robin R [Danville, CA; Benett, William J [Livermore, CA; Coleman, Matthew A [Oakland, CA; Pearson, Francesca S [Livermore, CA; Nasarabadi, Shanavaz L [Livermore, CA

2011-03-08

A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

Fatty acids rather than hormones restore in vitro angiogenesis in human male and female endothelial cells cultured in charcoal-stripped serum

PubMed Central

Vanetti, Claudia; Bifari, Francesco; Vicentini, Lucia M.

2017-01-01

Charcoal-stripped serum (CSS) is a well-accepted method to model effects of sex hormones in cell cultures. We have recently shown that human endothelial cells (ECs) fail to growth and to undergo in vitro angiogenesis when cultured in CSS. However, the mechanism(s) underlying the CSS-induced impairment of in vitro EC properties are still unknown. In addition, whether there is any sexual dimorphism in the CSS-induced EC phenotype remains to be determined. Here, by independently studying human male and female ECs, we found that CSS inhibited both male and female EC growth and in vitro angiogenesis, with a more pronounced effect on male EC sprouting. Reconstitution of CSS with 17-β estradiol, dihydrotestosterone, or the lipophilic thyroid hormone did not restore EC functions in both sexes. On the contrary, supplementation with palmitic acid or the acetyl-CoA precursor acetate significantly rescued the CSS-induced inhibition of growth and sprouting in both male and female ECs. We can conclude that the loss of metabolic precursors (e.g., fatty acids) rather than of hormones is involved in the impairment of in vitro proliferative and angiogenic properties of male and female ECs cultured with CSS. PMID:29232396

A fast and low-cost genotyping method for hepatitis B virus based on pattern recognition in point-of-care settings

PubMed Central

Qiu, Xianbo; Song, Liuwei; Yang, Shuo; Guo, Meng; Yuan, Quan; Ge, Shengxiang; Min, Xiaoping; Xia, Ningshao

2016-01-01

A fast and low-cost method for HBV genotyping especially for genotypes A, B, C and D was developed and tested. A classifier was used to detect and analyze a one-step immunoassay lateral flow strip functionalized with genotype-specific monoclonal antibodies (mAbs) on multiple capture lines in the form of pattern recognition for point-of-care (POC) diagnostics. The fluorescent signals from the capture lines and the background of the strip were collected via multiple optical channels in parallel. A digital HBV genotyping model, whose inputs are the fluorescent signals and outputs are a group of genotype-specific digital binary codes (0/1), was developed based on the HBV genotyping strategy. Meanwhile, a companion decoding table was established to cover all possible pairing cases between the states of a group of genotype-specific digital binary codes and the HBV genotyping results. A logical analyzing module was constructed to process the detected signals in parallel without program control, and its outputs were used to drive a set of LED indicators, which determine the HBV genotype. Comparing to the nucleic acid analysis to HBV viruses, much faster HBV genotyping with significantly lower cost can be obtained with the developed method. PMID:27306485

Measurement of labile copper in wine by medium exchange stripping potentiometry utilising screen printed carbon electrodes.

PubMed

Clark, Andrew C; Kontoudakis, Nikolaos; Barril, Celia; Schmidtke, Leigh M; Scollary, Geoffrey R

2016-07-01

The presence of copper in wine is known to impact the reductive, oxidative and colloidal stability of wine, and techniques enabling measurement of different forms of copper in wine are of particular interest in understanding these spoilage processes. Electrochemical stripping techniques developed to date require significant pretreatment of wine, potentially disturbing the copper binding equilibria. A thin mercury film on a screen printed carbon electrode was utilised in a flow system for the direct analysis of labile copper in red and white wine by constant current stripping potentiometry with medium exchange. Under the optimised conditions, including an enrichment time of 500s and constant current of 1.0μA, the response range was linear from 0.015 to 0.200mg/L. The analysis of 52 red and white wines showed that this technique generally provided lower labile copper concentrations than reported for batch measurement by related techniques. Studies in a model system and in finished wines showed that the copper sulfide was not measured as labile copper, and that loss of hydrogen sulfide via volatilisation induced an increase in labile copper within the model wine system. Copyright © 2016 Elsevier B.V. All rights reserved.

Study of the Mechanism of Liquid Slag Infiltration for Lubrication in Slab Continuous Casting

NASA Astrophysics Data System (ADS)

Zhang, Shaoda; Wang, Qiangqiang; He, Shengping; Wang, Qian

2018-04-01

Consistent and uniform lubrication of the solidifying shell, especially in the meniscus, is crucial for the smooth continuous casting operation and production of strands free of surface defects. Thus, the current study established a coupled model to study the inflow behavior of liquid slag to the mold-strand channel, taking the solidification of steel and slag and the periodic oscillation of mold into account. The difficulties and solutions for the simulation were described in detail. The predicted profiles of the slag rim and initial shell were in good agreement with the reports. The main results indicated that liquid slag could be squeezed out and back into the slag pool in a negative strip period while a large amount of liquid slag could infiltrate into the mold-strand channel. Thus, the amount of slag consumed in the negative strip period was relatively small compared with that in the positive strip period. The predicted variation of slag consumption during mold oscillation was periodic, and the average value was 0.274 kg/m2, which agreed well with the slag consumption in industrial practice. The current model can predict and optimize the oscillation parameters aiming at stable lubrication conditions.

Efficacy of adhesive strips to reduce postoperative periorbital edema and ecchymosis following rhinoplasty

PubMed

Tatar, Sedat; Bulam, Mehmet Hakan; Özmen, Selahattin

2018-02-23

Background/aim: Periorbital edema and ecchymosis may develop following rhinoplasty. The aim of this study was to assess the efficacy of adhesive strip application on the upper and lower eyelids to reduce postoperative edema and ecchymosis following rhinoplasty. Materials and methods: The eyelids of one side were randomly selected, and an adhesive strip of standard size and number was applied at the end of the operation. The strips were removed at postoperative day 3; photos of the eyes were taken at days 3 and 7. Edema and ecchymosis were graded on a scale from 1 to 4. The ecchymosis areas on the lower and upper eyelids were measured and compared in square centimeters. Results: The mean ecchymosis area of the lower eyelid on the side of the adhesive strip and on the side without the strip was 1.63 cm2 and 3.32 cm2 in the early period, respectively. It was 1.15 cm2 on the upper eyelid on the side of the adhesive strip, and 1.87 cm2 on the side without the strip. It was 0.224 cm2 on the side of the adhesive strip, and 0.498 cm2 on the side without the adhesive strip in the late period. Conclusion: Applying adhesive strips reduces periorbital edema and ecchymosis.

High resolution energy-sensitive digital X-ray

DOEpatents

Nygren, David R.

1995-01-01

An apparatus and method for detecting an x-ray and for determining the depth of penetration of an x-ray into a semiconductor strip detector. In one embodiment, a semiconductor strip detector formed of semiconductor material is disposed in an edge-on orientation towards an x-ray source such that x-rays From the x-ray source are incident upon and substantially perpendicular to the front edge of the semiconductor strip detector. The semiconductor strip detector is formed of a plurality of segments. The segments are coupled together in a collinear arrangement such that the semiconductor strip detector has a length great enough such that substantially all of the x-rays incident on the front edge of the semiconductor strip detector interact with the semiconductor material which forms the semiconductor strip detector. A plurality of electrodes are connected to the semiconductor strip detect or such that each one of the of semiconductor strip detector segments has at least one of the of electrodes coupled thereto. A signal processor is also coupled to each one of the electrodes. The present detector detects an interaction within the semiconductor strip detector, between an x-ray and the semiconductor material, and also indicates the depth of penetration of the x-ray into the semiconductor strip detector at the time of the interaction.

High resolution energy-sensitive digital X-ray

DOEpatents

Nygren, D.R.

1995-07-18

An apparatus and method for detecting an x-ray and for determining the depth of penetration of an x-ray into a semiconductor strip detector. In one embodiment, a semiconductor strip detector formed of semiconductor material is disposed in an edge-on orientation towards an x-ray source such that x-rays from the x-ray source are incident upon and substantially perpendicular to the front edge of the semiconductor strip detector. The semiconductor strip detector is formed of a plurality of segments. The segments are coupled together in a collinear arrangement such that the semiconductor strip detector has a length great enough such that substantially all of the x-rays incident on the front edge of the semiconductor strip detector interact with the semiconductor material which forms the semiconductor strip detector. A plurality of electrodes are connected to the semiconductor strip detector such that each one of the semiconductor strip detector segments has at least one of the of electrodes coupled thereto. A signal processor is also coupled to each one of the electrodes. The present detector detects an interaction within the semiconductor strip detector, between an x-ray and the semiconductor material, and also indicates the depth of penetration of the x-ray into the semiconductor strip detector at the time of the interaction. 5 figs.

Effects of the Tibetan herbal formula Padma Lax on visceral nociception and contractility of longitudinal smooth muscle in a rat model.

PubMed

Gschossmann, J M; Krayer, M; Flogerzi, B; Balsiger, B M

2010-09-01

The high prevalence of functional bowel disorders among the general population contrasts with the limited number of pharmacological treatment options for this condition. This has led to an interest for alternative therapeutic approaches. Padma Lax is an herbal laxative on the basis of Tibetan formulas. Our aim is to examine the effect of Padma Lax on visceral nociception in vivo and (B) on contractile activity of longitudinal smooth muscle of the lower gut in vitro and ex vivo. (A) Visceral sensory function in response to colorectal distension was assessed by abdominal wall electromyography in male Wistar rats pretreated with Padma Lax. (B) Effects of Padma Lax on contractility of gut smooth muscles were studied both in vitro with superfusion of the agent and ex vivo following oral administration of the preparation. Activities were measured as area under the curve. (A) For visceral sensitivity, no differences were observed between the Padma Lax and the control group. (B) Proximal colon muscle strips of the Padma Lax pretreated group showed significantly lower spontaneous contractility ex vivo than controls. Cholinergic procontractile stimulation was reduced in Padma Lax pretreated group and in colon strips of naive rats when Padma Lax was superfused in vitro (all P < 0.05). Cholinergic mechanisms appear to be important in the modulation of rat proximal colon contractility of orally and directly applied Padma Lax. These findings help elucidate a potential mechanism of action of this herbal remedy which has undergone clinical testing in patients with constipation predominant irritable bowel syndrome.

A Model for Space Shuttle Orbiter Tire Side Forces Based on NASA Landing Systems Research Aircraft Test Results

NASA Technical Reports Server (NTRS)

Carter, John F.; Nagy, Christopher J.; Barnicki, Joseph S.

1997-01-01

Forces generated by the Space Shuttle orbiter tire under varying vertical load, slip angle, speed, and surface conditions were measured using the Landing System Research Aircraft (LSRA). Resulting data were used to calculate a mathematical model for predicting tire forces in orbiter simulations. Tire side and drag forces experienced by an orbiter tire are cataloged as a function of vertical load and slip angle. The mathematical model is compared to existing tire force models for the Space Shuttle orbiter. This report describes the LSRA and a typical test sequence. Testing methods, data reduction, and error analysis are presented. The LSRA testing was conducted on concrete and lakebed runways at the Edwards Air Force Flight Test Center and on concrete runways at the Kennedy Space Center (KSC). Wet runway tire force tests were performed on test strips made at the KSC using different surfacing techniques. Data were corrected for ply steer forces and conicity.

An assessment of buffer strips for improving damage tolerance of composite laminates at elevated temperature

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1981-01-01

Buffer strips greatly improve the damage tolerance of graphite/epoxy laminates loaded in tension. Graphite/polyimide buffer strip panels were made and tested to determine their residual strength at ambient and elevated (177 C) temperature. Each panel was cut in the center to represent damage. Panels were radiographed and crack-opening displacements were recorded to indicate fracture, fracture arrest, and the extent of damage in the buffer strip after arrest. All panels had the same buffer strip spacing and width. The buffer strip material was 0 deg S-glass/PMR-15. The buffer strips were made by replacing narrow strips of the 0 deg graphite plies with strips of the 0 deg S-glass on either a one-for-one or a two-for-one basis. Half of the panels were heated to 177 + or - 3 C before and during the testing. Elevated temperature did not alter the fracture behavior of the buffer configuration.

Online aptitude automatic surface quality inspection system for hot rolled strips steel

NASA Astrophysics Data System (ADS)

Lin, Jin; Xie, Zhi-jiang; Wang, Xue; Sun, Nan-Nan

2005-12-01

Defects on the surface of hot rolled steel strips are main factors to evaluate quality of steel strips, an improved image recognition algorithm are used to extract the feature of Defects on the surface of steel strips. Base on the Machine vision and Artificial Neural Networks, establish a defect recognition method to select defect on the surface of steel strips. Base on these research. A surface inspection system and advanced algorithms for image processing to hot rolled strips is developed. Preparing two different fashion to lighting, adopting line blast vidicon of CCD on the surface steel strips on-line. Opening up capacity-diagnose-system with level the surface of steel strips on line, toward the above and undersurface of steel strips with ferric oxide, injure, stamp etc of defects on the surface to analyze and estimate. Miscarriage of justice and alternate of justice rate not preponderate over 5%.Geting hold of applications on some big enterprises of steel at home. Experiment proved that this measure is feasible and effective.

Stripped Elliptical Galaxies as Probes of ICM Physics. III. Deep Chandra Observations of NGC 4552: Measuring the Viscosity of the Intracluster Medium

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

Kraft, R. P.; Roediger, E.; Machacek, M.

We present results from a deep (200 ks) Chandra observation of the early-type galaxy NGC 4552 (M89), which is falling into the Virgo cluster. Previous shallower X-ray observations of this galaxy showed a remnant gas core, a tail to the South of the galaxy, and twin “horns” attached to the northern edge of the gas core. In our deeper data, we detect a diffuse, low surface brightness extension to the previously known tail, and measure the temperature structure within the tail. We combine the deep Chandra data with archival XMM-Newton observations to put a strong upper limit on the diffusemore » emission of the tail out to a large distance (10× the radius of the remnant core) from the galaxy center. In our two previous papers, we presented the results of hydrodynamical simulations of ram pressure stripping specifically for M89 falling into the Virgo cluster and investigated the effect of intracluster medium (ICM) viscosity. In this paper, we compare our deep data with our specifically tailored simulations and conclude that the observed morphology of the stripped tail in NGC 4552 is most similar to the inviscid models. We conclude that, to the extent the transport processes can be simply modeled as a hydrodynamic viscosity, the ICM viscosity is negligible. More generally, any micro-scale description of the transport processes in the high- β plasma of the cluster ICM must be consistent with the efficient mixing observed in the stripped tail on macroscopic scales.« less

Equilibrium and kinetic modeling of contaminant immobilization by activated carbon amended to sediments in the field.

PubMed

Rakowska, Magdalena I; Kupryianchyk, Darya; Koelmans, Albert A; Grotenhuis, Tim; Rijnaarts, Huub H M

2014-12-15

Addition of activated carbons (AC) to polluted sediments and soils is an attractive remediation technique aiming at reducing pore water concentrations of hydrophobic organic contaminants (HOCs). In this study, we present (pseudo-)equilibrium as well as kinetic parameters for sorption of a series of PAHs and PCBs to powdered and granular activated carbons (AC) after three different sediment treatments: sediment mixed with powdered AC (PAC), sediment mixed with granular AC (GAC), and addition of GAC followed by 2 d mixing and subsequent removal ('sediment stripping'). Remediation efficiency was assessed by quantifying fluxes of PAHs towards SPME passive samplers inserted in the sediment top layer, which showed that the efficiency decreased in the order of PAC > GAC stripping > GAC addition. Sorption was very strong to PAC, with Log KAC (L/kg) values up to 10.5. Log KAC values for GAC ranged from 6.3-7.1 and 4.8-6.2 for PAHs and PCBs, respectively. Log KAC values for GAC in the stripped sediment were 7.4-8.6 and 5.8-7.7 for PAH and PCB. Apparent first order adsorption rate constants for GAC (kGAC) in the stripping scenario were calculated with a first-order kinetic model and ranged from 1.6 × 10(-2) (PHE) to 1.7 × 10(-5) d(-1) (InP). Sorption affinity parameters did not change within 9 months post treatment, confirming the longer term effectiveness of AC in field applications for PAC and GAC. Copyright © 2014. Published by Elsevier Ltd.

Stripped Elliptical Galaxies as Probes of ICM Physics. III. Deep Chandra Observations of NGC 4552: Measuring the Viscosity of the Intracluster Medium

NASA Astrophysics Data System (ADS)

Kraft, R. P.; Roediger, E.; Machacek, M.; Forman, W. R.; Nulsen, P. E. J.; Jones, C.; Churazov, E.; Randall, S.; Su, Y.; Sheardown, A.

2017-10-01

We present results from a deep (200 ks) Chandra observation of the early-type galaxy NGC 4552 (M89), which is falling into the Virgo cluster. Previous shallower X-ray observations of this galaxy showed a remnant gas core, a tail to the South of the galaxy, and twin “horns” attached to the northern edge of the gas core. In our deeper data, we detect a diffuse, low surface brightness extension to the previously known tail, and measure the temperature structure within the tail. We combine the deep Chandra data with archival XMM-Newton observations to put a strong upper limit on the diffuse emission of the tail out to a large distance (10× the radius of the remnant core) from the galaxy center. In our two previous papers, we presented the results of hydrodynamical simulations of ram pressure stripping specifically for M89 falling into the Virgo cluster and investigated the effect of intracluster medium (ICM) viscosity. In this paper, we compare our deep data with our specifically tailored simulations and conclude that the observed morphology of the stripped tail in NGC 4552 is most similar to the inviscid models. We conclude that, to the extent the transport processes can be simply modeled as a hydrodynamic viscosity, the ICM viscosity is negligible. More generally, any micro-scale description of the transport processes in the high-β plasma of the cluster ICM must be consistent with the efficient mixing observed in the stripped tail on macroscopic scales.

Conformal partition functions of critical percolation from D 3 thermodynamic Bethe Ansatz equations

NASA Astrophysics Data System (ADS)

Morin-Duchesne, Alexi; Klümper, Andreas; Pearce, Paul A.

2017-08-01

Using the planar Temperley-Lieb algebra, critical bond percolation on the square lattice can be reformulated as a loop model. In this form, it is incorporated as {{ L}}{{ M}}(2, 3) in the Yang-Baxter integrable family of logarithmic minimal models {{ L}}{{ M}}( p, p\\prime) . We consider this model of percolation in the presence of boundaries and with periodic boundary conditions. Inspired by Kuniba, Sakai and Suzuki, we rewrite the recently obtained infinite Y-system of functional equations. In this way, we obtain nonlinear integral equations in the form of a closed finite set of TBA equations described by a D 3 Dynkin diagram. Following the methods of Klümper and Pearce, we solve the TBA equations for the conformal finite-size corrections. For the ground states of the standard modules on the strip, these agree with the known central charge c  =  0 and conformal weights Δ1, s for \\renewcommand≥≥slant} s\\in {{ Z}≥slant 1} with Δr, s=\\big((3r-2s){\\hspace{0pt}}^2-1\\big)/24 . For the periodic case, the finite-size corrections agree with the conformal weights Δ0, s , Δ1, s with \\renewcommand{≥{≥slant} s\\in\\frac{1}{2}{{ Z}≥slant 0} . These are obtained analytically using Rogers dilogarithm identities. We incorporate all finite excitations by formulating empirical selection rules for the patterns of zeros of all the eigenvalues of the standard modules. We thus obtain the conformal partition functions on the cylinder and the modular invariant partition function (MIPF) on the torus. By applying q-binomial and q-Narayana identities, it is shown that our refined finitized characters on the strip agree with those of Pearce, Rasmussen and Zuber. For percolation on the torus, the MIPF is a non-diagonal sesquilinear form in affine u(1) characters given by the u(1) partition function Z2, 3(q)=Z2, 3{Circ}(q) . The u(1) operator content is {{ N}}Δ, \\barΔ=1 for Δ=\\barΔ=-\\frac{1}{24}, \\frac{35}{24} and {{ N}}Δ, \\barΔ=2 for Δ=\\barΔ=\\frac{1}{8}, \\frac{1}{3}, \\frac{5}{8} and (Δ, \\barΔ)=(0, 1), (1, 0) . This result is compatible with the general conjecture of Pearce and Rasmussen, namely Zp, p\\prime(q)=Z{Proj}p, p\\prime(q)+np, p\\prime Z{Min}p, p\\prime(q) with np, p\\prime\\in {{ Z}} , where the minimal partition function is Z{Min}2, 3(q)=1 and the lattice derivation fixes n 2,3  =  -1.

Novel strip-cast Mg/Al clad sheets with excellent tensile and interfacial bonding properties

PubMed Central

Kim, Jung-Su; Lee, Dong Ho; Jung, Seung-Pill; Lee, Kwang Seok; Kim, Ki Jong; Kim, Hyoung Seop; Lee, Byeong-Joo; Chang, Young Won; Yuh, Junhan; Lee, Sunghak

2016-01-01

In order to broaden industrial applications of Mg alloys, as lightest-weight metal alloys in practical uses, many efforts have been dedicated to manufacture various clad sheets which can complement inherent shortcomings of Mg alloys. Here, we present a new fabrication method of Mg/Al clad sheets by bonding thin Al alloy sheet on to Mg alloy melt during strip casting. In the as-strip-cast Mg/Al clad sheet, homogeneously distributed equi-axed dendrites existed in the Mg alloy side, and two types of thin reaction layers, i.e., γ (Mg17Al12) and β (Mg2Al3) phases, were formed along the Mg/Al interface. After post-treatments (homogenization, warm rolling, and annealing), the interfacial layers were deformed in a sawtooth shape by forming deformation bands in the Mg alloy and interfacial layers, which favorably led to dramatic improvement in tensile and interfacial bonding properties. This work presents new applications to multi-functional lightweight alloy sheets requiring excellent formability, surface quality, and corrosion resistance as well as tensile and interfacial bonding properties. PMID:27245687

Novel strip-cast Mg/Al clad sheets with excellent tensile and interfacial bonding properties.

PubMed

Kim, Jung-Su; Lee, Dong Ho; Jung, Seung-Pill; Lee, Kwang Seok; Kim, Ki Jong; Kim, Hyoung Seop; Lee, Byeong-Joo; Chang, Young Won; Yuh, Junhan; Lee, Sunghak

2016-06-01

In order to broaden industrial applications of Mg alloys, as lightest-weight metal alloys in practical uses, many efforts have been dedicated to manufacture various clad sheets which can complement inherent shortcomings of Mg alloys. Here, we present a new fabrication method of Mg/Al clad sheets by bonding thin Al alloy sheet on to Mg alloy melt during strip casting. In the as-strip-cast Mg/Al clad sheet, homogeneously distributed equi-axed dendrites existed in the Mg alloy side, and two types of thin reaction layers, i.e., γ (Mg17Al12) and β (Mg2Al3) phases, were formed along the Mg/Al interface. After post-treatments (homogenization, warm rolling, and annealing), the interfacial layers were deformed in a sawtooth shape by forming deformation bands in the Mg alloy and interfacial layers, which favorably led to dramatic improvement in tensile and interfacial bonding properties. This work presents new applications to multi-functional lightweight alloy sheets requiring excellent formability, surface quality, and corrosion resistance as well as tensile and interfacial bonding properties.

A standardized procedure for using human corpus cavernosum strips to evaluate drug activity.

PubMed

Mirone, V; Sorrentino, R; di Villa Bianca, R; Imbimbo, C; Palmieri, A; Fusco, F; Tajana, G; Cirino, G

2000-01-01

The main problem of using human corpus cavernosum (HCC) tissue to perform bioassay is linked to its limited availability further complicated by the heterogeneous source of the tissues used. Here, we show that gender reassignment is a reliable source of human tissue without major ethical problems. Indeed, the entire corpus cavernosum is obtained from the surgery procedure, which allows creating a standardized procedure to prepare HCC strip. In addition, human tissue, if kept in the fridge in the condition described, does not loose its ability to contract to phenylephrine (PE; alpha agonist), angiotensin II (AG II) and KCl up to 4 days. Furthermore, once contracted with PE, HCC relaxes to acetylcholine (endothelium-dependent mechanism); sodium nitroprusside (endothelium-independent mechanism); cromakalim (CRK), a K(ATP) channel opener; or alprostadil, a synthetic PGE2 (ALPR). In conclusion, we have standardized a procedure that allows the use of HCC strips to evaluate drug activity and/or to study pathophysiological mechanisms with an intact functional human tissue up to 4 days from the surgery procedure.

High-efficiency surface plasmonic polariton waveguides with enhanced low-frequency performance in microwave frequencies.

PubMed

Zhang, Dawei; Zhang, Kuang; Wu, Qun; Ding, Xumin; Sha, Xuejun

2017-02-06

In this paper, a planar waveguide based on spoof surface plasmon polaritons (SSPPs) with metals on both sides of the corrugated strip as grounds is firstly proposed in microwave region. Simple and efficient conversion between guided waves and SSPPs is realized by gradient corrugated strip with grounds on both sides. Compared with plasmonic waveguide with flaring ground [Laser Photonics Rev. 8, 146 (2014)], the addition of grounds suppresses the radiation loss effectively and improves the low-frequency performance with tighter field confinement, which leads to a wider operating bandwidth. Moreover, as the asymptotic frequency of SSPPs decreasing, the confinement of SSPPs is further enhanced by a defected ground structure (DGS), which is achieved by the periodic grooves symmetrical to those on the corrugated strip. Therefore, miniaturization of the proposed waveguide can be realized. Measured results validate both high efficiency of momentum and impedance matching and enhanced performance in the region of lower frequencies with the wave vectors close to those in free space. Such results have significant values in plasmonic functional devices and integrated circuits in microwave frequencies.

21 CFR 882.5900 - Preformed craniosynostosis strip.

Code of Federal Regulations, 2012 CFR

2012-04-01

... craniosynostosis strip. (a) Identification. A preformed craniosynostosis strip is a plastic strip used to cover bone edges of craniectomy sites (sites where the skull has been cut) to prevent the bone from regrowing...

21 CFR 882.5900 - Preformed craniosynostosis strip.

Code of Federal Regulations, 2014 CFR

2014-04-01

... craniosynostosis strip. (a) Identification. A preformed craniosynostosis strip is a plastic strip used to cover bone edges of craniectomy sites (sites where the skull has been cut) to prevent the bone from regrowing...

21 CFR 882.5900 - Preformed craniosynostosis strip.

Code of Federal Regulations, 2013 CFR

2013-04-01

... craniosynostosis strip. (a) Identification. A preformed craniosynostosis strip is a plastic strip used to cover bone edges of craniectomy sites (sites where the skull has been cut) to prevent the bone from regrowing...

21 CFR 882.5900 - Preformed craniosynostosis strip.

Code of Federal Regulations, 2011 CFR

2011-04-01

... craniosynostosis strip. (a) Identification. A preformed craniosynostosis strip is a plastic strip used to cover bone edges of craniectomy sites (sites where the skull has been cut) to prevent the bone from regrowing...

Magnetic-Force-Assisted Straightening of Bent Mild Steel Strip by Laser Irradiation

NASA Astrophysics Data System (ADS)

Dutta, Polash P.; Kalita, Karuna; Dixit, Uday S.; Liao, Hengcheng

2017-12-01

This study proposes a technique to straighten bent metallic strips with magnetic-force-assisted laser irradiation. Experiments were conducted for three different types of mechanically-bent mild strips. The first type was bent strips without any heat treatment. The second type was stress-relieved and third type was subcritical-annealed bent strips. These strips were straightened following different schemes of laser irradiation sequence to understand the performance of straightening. A parametric study was conducted by varying laser power and scanning speed. Micro-hardness, tensile test, Charpy impact test and microstructure after straightening were also studied. Different scanning schemes provided different microstructures and mechanical properties. Any serious deterioration in the quality of straightened strips was not noticed. Overall, subcritical-annealed bent strips provided the best performance in straightening. The proposed straightening scheme has potential of becoming an industrial practice.

Method for maintaining precise suction strip porosities

NASA Technical Reports Server (NTRS)

Gallimore, Frank H. (Inventor)

1989-01-01

This invention relates to a masking method generally and, more particularly to a method of masking perforated titanium sheets having laminar control suction strips. As illustrated in the drawings, a nonaerodynamic surface of a perforated sheet has alternating suction strip areas and bonding land areas. Suction strip tapes overlie the bonding land areas during application of a masking material to an upper surface of the suction strip tapes. Prior to bonding the perforated sheet to a composite structure, the bonding land tapes are removed. The entire opposite aerodynamic surface is masked with tape before bonding. This invention provides a precise control of suction strip porosities by ensuring that no chemicals penetrate the suction strip areas during bonding.

Design of the scanning mode coated glass color difference online detection system

NASA Astrophysics Data System (ADS)

Bi, Weihong; Zhang, Yu; Wang, Dajiang; Zhang, Baojun; Fu, Guangwei

2008-03-01

A design of scanning mode coated glass color difference online detection system was introduced. The system consisted of color difference data acquirement part and orbit control part. The function of the color difference data acquirement part was to acquire glass spectral reflectance and then processed them to get the color difference value. Using fiber for light guiding, the reflected light from surface of glass was transmitted into light division part, and the dispersive light was imaged on linear CCD, and then the output signals from the CCD was sampled pixel by pixel, and the spectral reflectance of coated glass was obtained finally. Then, the acquired spectral reflectance signals was sent to industrial personal computer through USB interface, using standard color space and color difference formula nominated by International Commission on Illumination (CIE) in 1976 to process these signals, and the reflected color parameter and color difference of coated glass was gained in the end. The function of the orbit control part was to move the detection probe by way of transverse scanning mode above the glass strip, and control the measuring start-stop time of the color difference data acquirement part at the same time. The color difference data acquirement part of the system was put on the orbit which is after annealing area in coated glass production line, and the protected fiber probe was placed on slide of the orbit. Using single chip microcomputer to control transmission mechanism of the slide, which made the slide move by way of transverse scanning mode on the glass strip, meanwhile, the color difference data acquirement part of the system was also controlled by the single chip microcomputer, and it made the acquirement part measure color difference data when the probe reached the needed working speed and required place on the glass strip. The scanning mode coated glass color difference online detection system can measure color parameter and color difference of each transverse point on glass strip, it can also measure lengthways color stability on glass strip. Furthermore, the measuring results can be transmitted to coated control room through intranet, so it is very useful to improve producing technique in time. In addition, equipping necessary marking machine, this system can classify glass board automatically based on the measuring result.

The expression of β3-adrenoceptors and their function in the human prostate.

PubMed

Suzuki, Takahisa; Otsuka, Atsushi; Matsumoto, Rikiya; Furuse, Hiroshi; Ozono, Seiichiro

2016-02-01

Little is known about β3-adrenoceptor (AR) expression and function in human prostate. We examined the expression and distribution of β-AR subtypes in normal prostate and benign prostatic hyperplasia (BPH) tissues, and investigated which selective β-AR subtype agonist was most involved in the relaxation of isolated human prostate strips. Messenger RNA (mRNA) expression for β1-, β2-, and β3 -ARs was investigated using reverse transcriptase-polymerase chain reactions (RT-PCR). Quantitative analysis of mRNA expression of β-AR subtypes between normal prostate and BPH tissues was performed using quantitative RT-PCR (qPCR). Distributions were examined by immunohistochemistry (IHC). Strips of human normal prostate or BPH were suspended in organ baths and exposed to isoproterenol, dobutamine, procaterol, and TRK-380 to investigate their relaxant effects on KCl-induced contractions, and their inhibitory effects on electrical field stimulation (EFS)-induced contractions. We confirmed the presence of mRNA for β1-, β2-, and β3-ARs both in normal prostate and in BPH tissues. For β3-AR, mRNA expression in BPH tissues was significantly higher than in normal prostate tissues, but there was no significant difference in β1- and β2-AR expression between normal and BPH tissues. IHC revealed differences in staining intensity between smooth muscle cells and glandular cells, with different proportions for different β-AR subtypes. Staining of β3-AR was particularly intense in smooth muscle cells as opposed to glandular cells. Isoproterenol and TRK-380 significantly decreased the tone of KCl-induced contractions of the normal prostate strips. The rank order of relaxant effects was isoproterenol > TRK-380 > procaterol > dobutamine. All selective β-AR agonists significantly decreased the amplitude of EFS-induced contractions of the normal prostate strips. The rank order of inhibitory effects was isoproterenol > dobutamine >TRK-380 > procaterol. In BPH strips, all selective β-AR agonists showed no significant relaxant or inhibitory effects on KCl- or EFS-induced contractions. β3 -AR is abundant in human prostate smooth muscle, whose relaxation is mediated by β1- and β3-AR stimulation. β3-AR agonists may have clinical use in the treatment of male non-BPH patients or neurogenic bladder patients with voiding dysfunction. © 2015 Wiley Periodicals, Inc.

Spatially distinct responses within willow to bark stripping by deer: effects on insect herbivory

NASA Astrophysics Data System (ADS)

Tanaka, Motonobu; Nakamura, Masahiro

2015-10-01

Within individual plants, cervid herbivory may cause positive or negative plant-mediated effects on insect herbivores, depending on where it occurs. Using a combination of field observations and artificial bark-stripping experiments in Hokkaido, Japan, we examined the plant-mediated effects of bark stripping by sika deer ( Cervus nippon yesoensis) on insect herbivory in two spatially distinct parts of willow ( Salix udensis) trees: resprouting leaves below bark-stripping wounds and canopy leaves above. Natural and artificial bark stripping stimulated resprouting from trunks below wounds. Resprouting leaves on bark-stripped trees had lower total phenolics, condensed tannin, and C/N ratios than did canopy leaves on control trees. Herbivory rates were higher in resprouting leaves on bark-stripped trees than in canopy leaves on controls. Conversely, above-wound canopy leaves on bark-stripped trees had higher total phenolics than did those on controls, while herbivory rates were lower in the canopy leaves of bark-stripped trees than in those on controls. These results demonstrate that plant-mediated effects of bark stripping diverge between plant tissues below and above wounds in individual willow trees. We submit that focusing on multiple plant parts can elucidate plant-mediated effects at the whole-plant scale.

Near-field nano-imager

NASA Technical Reports Server (NTRS)

Liu, Boyang (Inventor); Ho, Seng-Tiong (Inventor)

2010-01-01

An imaging device. In one embodiment, the imaging device includes a plurality of first electrode strips in parallel to each other along a first direction x, wherein each first electrode strip has an elongated body with a first surface and an opposite, second surface and a thickness n.sub.1. The imaging device also includes a plurality of second electrode strips in parallel to each other along a second direction y that is substantially perpendicular to the first direction x, wherein each second electrode strip has an elongated body with a first surface and an opposite, second surface and a thickness n.sub.2. The plurality of second electrode strips are positioned apart from the plurality of first electrode strips along a third direction z that is substantially perpendicular to the first direction x and the second direction y such that the plurality of first electrode strips and the plurality of second electrode strips are crossing each other accordingly to form a corresponding number of crossing points. And at each crossing point, a semiconductor component is filled between the second surface of a corresponding first electrode strip and the first surface of a corresponding second electrode strip to form an addressable pixel.

Water Damage to Asphalt Overlays: Case Histories

DOT National Transportation Integrated Search

1989-02-01

Numerous papers have been published on the phenomenon of stripping, especially on the possible causes of stripping, methods for predicting stripping potential of asphalt paving mixtures, and use of additives to minimize or prevent stripping. However,...

Mathematical Modeling of the Effect of Roll Diameter on the Thermo-Mechanical Behavior of Twin Roll Cast AZ31 Magnesium Alloy Strips

NASA Astrophysics Data System (ADS)

Hadadzadeh, Amir; Wells, Mary

Although the Twin Roll Casting (TRC) process has been used in the aluminum sheet production industry for more than 60 years, the usage of this process to fabricate magnesium sheets is still at its early stages. Similar to other manufacturing processes, the development of the TRC process for magnesium alloys has followed a typical route of preliminary studies using a laboratory-scale facility, followed by pilot-scale testing and most recently attempting to use an industrial-scale twin roll caster. A powerful tool to understand and quantify the trends of the processing conditions and effects of scaling up from a laboratory size TRC machine to an industrial scale one is develop a mathematical model of the process. This can elucidate the coupled fluid-thermo-mechanical behavior of the cast strip during the solidification and then deformation stages of the process. In the present study a Thermal-Fluid-Stress model has been developed for TRC of AZ31 magnesium alloy for three roll diameters by employing the FEM commercial package ALSIM. The roll diameters were chosen as 355mm, 600mm and 1150mm. The effect of casting speed for each diameter was studied in terms of fluid flow, thermal history and stress-strain evolution in the cast strip in the roll bite region.

Phosphorus load to surface water from bank erosion in a Danish lowland river basin.

PubMed

Kronvang, Brian; Audet, Joachim; Baattrup-Pedersen, Annette; Jensen, Henning S; Larsen, Søren E

2012-01-01

Phosphorus loss from bank erosion was studied in the catchment of River Odense, a lowland Danish river basin, with the aim of testing the hypothesis of whether stream banks act as major diffuse phosphorus (P) sources at catchment scale. Furthermore, the study aimed at analyzing the impact of different factors influencing bank erosion and P loss such as stream order, anthropogenic disturbances, width of uncultivated buffer strips, and the vegetation of buffer strips. A random stratified procedure in geographical information system (GIS) was used to select two replicate stream reaches covering different stream orders, channelized vs. naturally meandering channels, width of uncultivated buffer strips (≤ 2 m and ≥ 10 m), and buffer strips with different vegetation types. Thirty-six 100-m stream reaches with 180 bank plots and a total of 3000 erosion pins were established in autumn 2006, and readings were conducted during a 3-yr period (2006-2009). The results show that neither stream size nor stream disturbance measured as channelization of channel or the width of uncultivated buffer strip had any significant ( < 0.05) influence on bank erosion and P losses during each of the 3 yr studied. In buffer strips with natural trees bank erosion was significantly ( < 0.05) lower than in buffer strips dominated by grass and herbs. Gross and net P input from bank erosion amounted to 13.8 to 16.5 and 2.4 to 6.3 t P, respectively, in the River Odense catchment during the three study years. The net P input from bank erosion equaled 17 to 29% of the annual total P export and 21 to 62% of the annual export of P from diffuse sources from the River Odense catchment. Most of the exported total P was found to be bioavailable (71.7%) based on a P speciation of monthly suspended sediment samples collected at the outlet of the river basin. The results found in this study have a great importance for managers working with P mitigation and modeling at catchment scale. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Antenna with distributed strip and integrated electronic components

DOEpatents

Rodenbeck, Christopher T [Albuquerque, NM; Payne, Jason A [Albuquerque, NM; Ottesen, Cory W [Albuquerque, NM

2008-08-05

An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element can be in proximity to a ground conductor and/or arranged as a dipole. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. An antenna can comprise a distributed strip patterned on a printed wiring board, integrated with electronic components mounted on top of or below the distributed strip, and substantially within the extents of the distributed strip. Mounting of electronic components on top of or below the distributed strip has little effect on the performance of the antenna, and allows for realizing the combination of the antenna and integrated components in a compact form. An embodiment of the invention comprises an antenna including a distributed strip, integrated with a battery mounted on the distributed strip.

Rolled-up transformer structure for a radiofrequency integrated circuit (RFIC)

DOEpatents

Li, Xiuling; Huang, Wen

2016-05-03

A rolled-up transformer structure comprises a multilayer sheet having a rolled configuration comprising multiple turns about a longitudinal axis. The multilayer sheet comprises more than one conductive pattern layer on a strain-relieved layer, including a first conductive film and a second conductive film separated from the first conductive film in a thickness direction. The first conductive film comprises an even number of primary conductive strips, where each primary conductive strip has a length extending in the rolling direction, and the second conductive film comprises an even number of secondary conductive strips, where each secondary conductive strip has a length extending in the rolling direction. In the rolled configuration, turns of the primary conductive strips and turns of the secondary conductive strips wrap around the longitudinal axis. The primary conductive strips serve as a primary winding and the secondary conductive strips serve as a secondary winding of the rolled-up transformer structure.

Brief report: assessment of the social-emotional profile in children with autism spectrum disorders using a novel comic strip task.

PubMed

Sivaratnam, Carmel S; Cornish, Kim; Gray, Kylie M; Howlin, Patricia; Rinehart, Nicole J

2012-11-01

This study investigated whether the novel Comic Strip Task (CST) could be used to detect Theory-of-Mind impairments (ToM) in 4- to 8-year-old children with high functioning Autism Spectrum Disorders (ASD). Twelve children with either high-functioning autism or Asperger's Disorder and 12 typically-developing children completed the 21-item measure. The overall CST demonstrated moderate internal consistency but the Belief-understanding subscale was excluded from the test due to poor reliability. As predicted, the ASD group performed significantly more poorly than controls on the overall 2-subscale CST and on the intention-understanding subscale. No group differences were found in emotion-understanding subscale performance. Controlling for age, verbal ability was positively correlated with overall CST performance across groups. CST performance in the ASD group positively correlated with parent-reports of communication difficulties. Despite some limitations with the belief-understanding subscale, the CST has promising psychometric features warranting further development of this measure.

Towards non- and minimally instrumented, microfluidics-based diagnostic devices†

PubMed Central

Weigl, Bernhard; Domingo, Gonzalo; LaBarre, Paul; Gerlach, Jay

2009-01-01

In many health care settings, it is uneconomical, impractical, or unaffordable to maintain and access a fully equipped diagnostics laboratory. Examples include home health care, developing-country health care, and emergency situations in which first responders are dealing with pandemics or biowarfare agent release. In those settings, fully disposable diagnostic devices that require no instrument support, reagent, or significant training are well suited. Although the only such technology to have found widespread adoption so far is the immunochromatographic rapid assay strip test, microfluidics holds promise to expand the range of assay technologies that can be performed in formats similar to that of a strip test. In this paper, we review progress toward development of disposable, low-cost, easy-to-use microfluidics-based diagnostics that require no instrument at all. We also present examples of microfluidic functional elements—including mixers, separators, and detectors—as well as complete microfluidic devices that function entirely without any moving parts and external power sources. PMID:19023463

Intraply Hybrid Composites Would Contain Control Strips

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Shiao, Chi-Yu

1996-01-01

"Smart" structural components with sensors and/or actuators distributed throughout their volumes made of intraply hybrid composite materials, according to proposal. Strips of hybrid control material interspersed with strips of ordinary (passive) composite material in some layers, providing distributed control capability. For example, near and far edges of plate bent upward by commanding bottom control strips to expand and simultaneously commanding upper control strips to contract.

Modification of the tear function index and its use in the diagnosis of Sjögren's syndrome

PubMed Central

Kaye, S.; Sims, G.; Willoughby, C.; Field, A.; Longman, L.; Brown, M.

2001-01-01

BACKGROUND—The tear function index (TFI) has been shown to be of value in the diagnosis of patients suffering from Sjögren's syndrome. It is dependent, however, on introducing into the conjunctival fornix the correct concentration of fluorescein in at least one and a half times the normal tear volume. The stimulus and effect of this added volume on the tear dynamics is likely to vary between individuals. These factors, together with the method of performing the test, limit its general applicability.
AIM—To devise a method of performing the TFI with less variability and more general applicability. To present a theoretical and in vitro assessment of the dynamics of the TFI.
METHOD—The study was divided into three parts. The first part was to compare the results obtained using a prepared strip containing 1.3 µl of 0.5% fluorescein with the introduction of the same amount of fluorescein as a drop. The second part was to compare the results obtained with prepared strips with the standard method of performing the TFI, both with and without topical anaesthetic. The third part was an in vitro study of the rate of flow of graded volumes on a filter paper strip. 42 subjects with a diagnosis of Sjögren's syndrome according to the European criteria and 126 without Sjögren's syndrome were included.
RESULTS—There was no significant difference between the results obtained with a prepared strip and the introduction of 1.3 µl into the eye before performing the Schirmer's test and TFI (0.1

Substructure of fuzzy dark matter haloes

NASA Astrophysics Data System (ADS)

Du, Xiaolong; Behrens, Christoph; Niemeyer, Jens C.

2017-02-01

We derive the halo mass function (HMF) for fuzzy dark matter (FDM) by solving the excursion set problem explicitly with a mass-dependent barrier function, which has not been done before. We find that compared to the naive approach of the Sheth-Tormen HMF for FDM, our approach has a higher cutoff mass and the cutoff mass changes less strongly with redshifts. Using merger trees constructed with a modified version of the Lacey & Cole formalism that accounts for suppressed small-scale power and the scale-dependent growth of FDM haloes and the semi-analytic GALACTICUS code, we study the statistics of halo substructure including the effects from dynamical friction and tidal stripping. We find that if the dark matter is a mixture of cold dark matter (CDM) and FDM, there will be a suppression on the halo substructure on small scales which may be able to solve the missing satellites problem faced by the pure CDM model. The suppression becomes stronger with increasing FDM fraction or decreasing FDM mass. Thus, it may be used to constrain the FDM model.

A kinetic study of struvite precipitation recycling technology with NaOH/Mg(OH)2 addition.

PubMed

Yu, Rongtai; Ren, Hongqiang; Wang, Yanru; Ding, Lili; Geng, Jingji; Xu, Ke; Zhang, Yan

2013-09-01

Struvite precipitation recycling technology is received wide attention in removal ammonium and phosphate out of wastewater. While past study focused on process efficiency, and less on kinetics. The kinetic study is essential for the design and optimization in the application of struvite precipitation recycling technology. The kinetics of struvite with NaOH/Mg(OH)2 addition were studied by thermogravimetry analysis with three rates (5, 10, 20 °C/min), using Friedman method and Ozawa-Flynn-Wall method, respectively. Degradation process of struvite with NaOH/Mg(OH)2 addition was three steps. The stripping of ammonia from struvite was mainly occurred at the first step. In the first step, the activation energy was about 70 kJ/mol, which has gradually declined as the reaction progress. By model fitting studies, the proper mechanism function for struvite decomposition process with NaOH/Mg(OH)2 addition was revealed. The mechanism function was f(α)=α(α)-(1-α)(n), a Prout-Tompkins nth order (Bna) model. Copyright © 2013 Elsevier Ltd. All rights reserved.

Buffer strips in composites at elevated temperature

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1983-01-01

The composite material 'buffer strip' concept is presently investigated at elevated temperatures for the case of graphite/polyimide buffer strip panels using a (45/0/45/90)2S layup, where the buffer strip material was 0-deg S-glass/polyimide. Each panel was loaded in tension until it failed, and radiographs and crack opening displacements were recorded during the tests to determine fracture onset, fracture arrest, and the extent of damage in the buffer strip after crack arrest. At 177 + or - 3 C, the buffer strips increased the panel strength by at least 40 percent in comparison with panels without buffer strips. Compared to similar panels tested at room temperature, those tested at elevated temperature had lower residual strengths, but higher failure strains.

Assessment of practicality of remote sensing techniques for a study of the effects of strip mining in Alabama

NASA Technical Reports Server (NTRS)

Hughes, T. H.; Dillion, A. C., III; White, J. R., Jr.; Drummond, S. E., Jr.; Hooks, W. G.

1975-01-01

Because of the volume of coal produced by strip mining, the proximity of mining operations, and the diversity of mining methods (e.g. contour stripping, area stripping, multiple seam stripping, and augering, as well as underground mining), the Warrior Coal Basin seemed best suited for initial studies on the physical impact of strip mining in Alabama. Two test sites, (Cordova and Searles) representative of the various strip mining techniques and environmental problems, were chosen for intensive studies of the correlation between remote sensing and ground truth data. Efforts were eventually concentrated in the Searles Area, since it is more accessible and offers a better opportunity for study of erosional and depositional processes than the Cordova Area.

Development and evaluation of an immunochromatographic strip for rapid screening of sildenafil-type compounds as illegal additives in functional foods.

PubMed

Guo, Jiebiao; Liu, Wangpei; Lan, Xianquan; Chen, Hualong; Xiao, Zijun

2016-07-01

Sildenafil is a phosphodiesterase-5 inhibitor (PDE-5) for the treatment of erectile dysfunction. Undeclared sildenafil and related analogues adulterated in functional foods are a threat to public health. To screen these illegal drugs rapidly in herbal samples, an immunochromatographic (IC) assay was developed based on polyclonal antibodies specific to both sildenafil and its analogues. A group that is pharmacological necessary for sildenafil and its analogues was employed as a representative hapten for the generation antibodies against the target compounds. The desired antisera showed satisfactory specificities to sildenafil and major analogues with IC50 values ranging from 19.3 to 34.6 ng ml(-1) in a referring enzyme-linked immunosorbent assay (ELISA). The optimised IC assay showed detection thresholds in the range 5.0-20 μg g(-1) for sildenafil and major analogues in herbal samples. Sixty herbal food supplements were screened and six were found to be positive using the IC strip. It was confirmed by ELISA and UPLC-PDA-MS/MS that positive samples contain target illegal additives in levels of 10-40 mg g(-1) (1-4%). In this range, sensitivity of the IC strip is adequate to screen sildenafil-type compounds in herbal commodities under a dilution ratio of 1:10(3). Thus, the current IC assay is a suitable tool for screening sildenafil and its analogues as illegal additives in herbal food supplements.

Bicycle-Friendly Shoulder Rumble Strips

DOT National Transportation Integrated Search

2000-03-01

Shoulder rumble strips have proven to be an effective way to reduce run-off-the-road (ROR) crashes on urban and rural freeways. As the use of shoulder rumble strips is being extended to non-freeway facilities, bicyclists will encounter rumble strips ...

FDTD subcell graphene model beyond the thin-film approximation

NASA Astrophysics Data System (ADS)

Valuev, Ilya; Belousov, Sergei; Bogdanova, Maria; Kotov, Oleg; Lozovik, Yurii

2017-01-01

A subcell technique for calculation of optical properties of graphene with the finite-difference time-domain (FDTD) method is presented. The technique takes into account the surface conductivity of graphene which allows the correct calculation of its dispersive response for arbitrarily polarized incident waves interacting with the graphene. The developed technique is verified for a planar graphene sheet configuration against the exact analytical solution. Based on the same test case scenario, we also show that the subcell technique demonstrates a superior accuracy and numerical efficiency with respect to the widely used thin-film FDTD approach for modeling graphene. We further apply our technique to the simulations of a graphene metamaterial containing periodically spaced graphene strips (graphene strip-grating) and demonstrate good agreement with the available theoretical results.

La structure de Jordan des matrices de transfert des modeles de boucles et la relation avec les hamiltoniens XXZ

NASA Astrophysics Data System (ADS)

Morin-Duchesne, Alexi

Lattice models such as percolation, the Ising model and the Potts model are useful for the description of phase transitions in two dimensions. Finding analytical solutions is done by calculating the partition function, which in turn requires finding eigenvalues of transfer matrices. At the critical point, the two dimensional statistical models are invariant under conformal transformations and the construction of rational conformal field theories, as the continuum limit of these lattice models, allows one to compute the partition function at the critical point. Many researchers think however that the paradigm of rational conformal conformal field theories can be extended to include models with non diagonalizable transfer matrices. These models would then be described, in the scaling limit, by logarithmic conformal field theories and the representations of the Virasoro algebra coming into play would be indecomposable. We recall the construction of the double-row transfer matrix DN (λ, u) of the Fortuin-Kasteleyn model, seen as an element of the Temperley-Lieb algebra. This transfer matrix comes into play in physical theories through its representation in link modules (or standard modules). The vector space on which this representation acts decomposes into sectors labelled by a physical parameter d, the number of defects, which remains constant or decreases in the link representations. This thesis is devoted to the identification of the Jordan structure of DN(λ, u) in the link representations. The parameter β = 2 cos λ = -(q + q-1) fixes the theory : for instance β = 1 for percolation and 2 for the Ising model. On the geometry of the strip with open boundary conditions, we show that DN(λ, u) has the same Jordan blocks as its highest Fourier coefficient, FN. We study the non-diagonalizability of FN through the divergences of some of the eigenstates of ρ(F N) that appear at the critical values of λ. The Jordan cells we find in ρ(DN(λ, u)) have rank 2 and couple sectors d and d' when specific constraints on λ, d, d' and N are satisfied. For the model of critical dense polymers (β = 0) on the strip, the eigenvalues of ρ(DN(λ, u)) were known, but their degeneracies only conjectured. By constructing an isomorphism between the link modules on the strip and a subspace of spin modules of the XXZ model at q = i, we prove this conjecture. We also show that the restriction of the Hamiltonian to any sector d is diagonalizable, and that the XX Hamiltonian has rank 2 Jordan cells when N is even. Finally, we study the Jordan structure of the transfer matrix T N(λ, ν) for periodic boundary conditions. When λ = πa/b and a, b ∈ Z× , the matrix TN(λ, ν) has Jordan blocks between sectors, but also within sectors. The approach using FN admits a generalization to the present case and allows us to probe the Jordan cells that tie different sectors. The rank of these cells exceeds 2 in some cases and can grow indefinitely with N. For the Jordan blocks within a sector, we show that the link modules on the cylinder and the XXZ spin modules are isomorphic except for specific curves in the (q, ν) plane. By using the behavior of the transformation ĩd N in a neighborhood of the critical values (qc, ν c), we explicitly build Jordan partners of rank 2 and discuss the existence of Jordan cells with higher rank. Keywords : phase transitions, Ising model, Potts model, Fortuin-Kasteleyn model, transfer matrix method, XXZ Hamiltonian, logarithmic conformal field theory, Jordan structure.

A Model for Ferroelectric Phase Shifters

NASA Technical Reports Server (NTRS)

Romanofsky, Robert R.; Qureshi, A. Haq

2000-01-01

Novel microwave phase shifters consisting of coupled microstrip lines on thin ferroelectric films have been demonstrated recently. A theoretical model useful for predicting the propagation characteristics (insertion phase shift, dielectric loss, impedance, and bandwidth) is presented here. The model is based on a variational solution for line capacitance and coupled strip transmission line theory.

Introduction to Population Modeling.

ERIC Educational Resources Information Center

Frauenthal, James C.

The focus is on the formulation and solution of mathematical models with the idea of a population employed mainly as a pedogogical tool. If the biological setting is stripped away, the material can be interpreted as topics or the qualitative behavior of differential and difference equations. The first group of models investigate the dynamics of a…

Synthesis of Shoulder Rumble Strip Practices and Policies.

DOT National Transportation Integrated Search

2001-12-07

This synthesis provides a review of shoulder rumble strip research and the rumble strips' crash reduction record. A discussion of shoulder rumble strips as perceived by the motorist and the bicyclist is followed by the presentation of results of thre...

An algorithm for surface smoothing with rational splines

NASA Technical Reports Server (NTRS)

Schiess, James R.

1987-01-01

Discussed is an algorithm for smoothing surfaces with spline functions containing tension parameters. The bivariate spline functions used are tensor products of univariate rational-spline functions. A distinct tension parameter corresponds to each rectangular strip defined by a pair of consecutive spline knots along either axis. Equations are derived for writing the bivariate rational spline in terms of functions and derivatives at the knots. Estimates of these values are obtained via weighted least squares subject to continuity constraints at the knots. The algorithm is illustrated on a set of terrain elevation data.

Post-test evaluation of the geology, geochemistry, microbiology, and hydrology of the in situ air stripping demonstration site at the Savannah River Site

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

Eddy Dilek, C.A.; Looney, B.B.; Hazen, T.C.

A full-scale demonstration of the use of horizontal wells for in situ air stripping for environment restoration was completed as part of the Savannah River Integrated Demonstration Program. The demonstration of in situ air stripping was the first in a series of demonstrations of innovative remediation technologies for the cleanup of sites contaminated with volatile organic contaminants. The in situ air stripping system consisted of two directionally drilled wells that delivered gases to and extract contamination from the subsurface. The demonstration was designed to remediate soils and sediments in the unsaturated and saturated zones as well as groundwater contaminated withmore » volatile organic compounds. The demonstration successfully removed significant quantities of solvent from the subsurface. The field site and horizontal wells were subsequently used for an in situ bioremediation demonstration during which methane was added to the injected air. The field conditions documented herein represent the baseline status of the site for evaluating the in situ bioremediation as well as the post-test conditions for the in situ air stripping demonstration. Characterization activities focused on documenting the nature and distribution of contamination in the subsurface. The post-test characterization activities discussed herein include results from the analysis of sediment samples, three-dimensional images of the pretest and post-test data, contaminant inventories estimated from pretest and post-test models, a detailed lithologic cross sections of the site, results of aquifer testing, and measurements of geotechnical parameters of undisturbed core sediments.« less

Study on shear strengthening of RC continuous T-beams using different layers of CFRP strips

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

Alferjani, M. B. S.; Samad, A. A. Abdul; Mohamad, Noridah

2015-05-15

Carbon fiber reinforced polymer (CFRP) laminates are externally bonded to reinforced concrete (RC) members to provide additional strength such as flexural, shear, etc. However, this paper presents the results of an experimental investigation for enhancing the shear capacity of reinforced concrete (RC) continuous T- beams using different layers of CFRP wrapping schemes. A total of three concrete beams were tested and various sheet configurations and layouts were studied to determine their effects on ultimate shear strength and shear capacity of the beams. One beam was kept as control beams, while other beams were strengthened with externally bonded CFRP strips withmore » three side bonding and one or two layers of CFRP strips. From the test results, it was found that all schemes were found to be effective in enhancing the shear strength of RC beams. It was observed that the strength increases with the number of sheet layers provided the most effective strengthening for RC continuous T- beam. Beam strengthened using this scheme showed 23.21% increase in shear capacity as compared to the control beam. Two prediction models available in literature were used for computing the contribution of CFRP strips and compared with the experimental results.« less

Gauge Factor and Stretchability of Silicon-on-Polymer Strain Gauges

PubMed Central

Yang, Shixuan; Lu, Nanshu

2013-01-01

Strain gauges are widely applied to measure mechanical deformation of structures and specimens. While metallic foil gauges usually have a gauge factor slightly over 2, single crystalline silicon demonstrates intrinsic gauge factors as high as 200. Although silicon is an intrinsically stiff and brittle material, flexible and even stretchable strain gauges have been achieved by integrating thin silicon strips on soft and deformable polymer substrates. To achieve a fundamental understanding of the large variance in gauge factor and stretchability of reported flexible/stretchable silicon-on-polymer strain gauges, finite element and analytically models are established to reveal the effects of the length of the silicon strip, and the thickness and modulus of the polymer substrate. Analytical results for two limiting cases, i.e., infinitely thick substrate and infinitely long strip, have found good agreement with FEM results. We have discovered that strains in silicon resistor can vary by orders of magnitude with different substrate materials whereas strip length or substrate thickness only affects the strain level mildly. While the average strain in silicon reflects the gauge factor, the maximum strain in silicon governs the stretchability of the system. The tradeoff between gauge factor and stretchability of silicon-on-polymer strain gauges has been proposed and discussed. PMID:23881128

Crystallography and Molecular Arrangement of Polymorphic Monolayer J-Aggregates of a Cyanine Dye: Multiangle Polarized Light Fluorescence Optical Microscopy Study.

PubMed

Prokhorov, Valery V; Pozin, Sergey I; Perelygina, Olga M; Mal'tsev, Eugene I

2018-04-24

The molecular orientation in monolayer J-aggregates of 3,3-di(γ-sulfopropyl)-5,5-dichlorotiamonomethinecyanine dye has been precisely estimated using improved linear polarization measurements in the fluorescence microscope in which a multiangle set of polarization data is obtained using sample rotation. The estimated molecular orientation supplemented with the previously established crystallographic constraints based on the analysis of the well-developed two-dimensional J-aggregate shapes unambiguously indicate the staircase type of molecular arrangement for striplike J-aggregates with the staircases oriented along strips. The molecular transition dipoles are inclined at an angle of ∼25° to the strip direction, whereas the characteristic strip vertex angle ∼45° is formed by the [100] and [1-10] directions of the monoclinic unit cell. Measurements of the geometry of partially unwound tubes and their polarization properties support the model of tube formation by close-packed helical winding of flexible monolayer strips. In the tubes, the long molecular axes are oriented at a small angle in the range of 5-15° to the normal to the tube axis providing low bending energy. At a nanoscale, high-resolution atomic force microscopy imaging of J-aggregate monolayers reveals a complex quasi-one-dimensional organization.

Biodegradation of paint stripper solvents in a modified gas lift loop bioreactor.

PubMed

Vanderberg-Twary, L; Steenhoudt, K; Travis, B J; Hanners, J L; Foreman, T M; Brainard, J R

1997-07-05

Paint stripping wastes generated during the decontamination and decommissioning of former nuclear facilities contain paint stripping organics (dichloromethane, 2-propanol, and methanol) and bulk materials containing paint pigments. It is desirable to degrade the organic residues as part of an integrated chemical-biological treatment system. We have developed a modified gas lift loop bioreactor employing a defined consortium of Rhodococcus rhodochrous strain OFS and Hyphomicrobium sp. DM-2 that degrades paint stripper organics. Mass transfer coefficients and kinetic constants for biodegradation in the system were determined. It was found that transfer of organic substrates from surrogate waste into the air and further into the liquid medium in the bioreactor were rapid processes, occurring within minutes. Monod kinetics was employed to model the biodegradation of paint stripping organics. Analysis of the bioreactor process was accomplished with BIOLAB, a mathematical code that simulates coupled mass transfer and biodegradation processes. This code was used to fit experimental data to Monod kinetics and to determine kinetic parameters. The BIOLAB code was also employed to compare activities in the bioreactor of individual microbial cultures to the activities of combined cultures in the bioreactor. This code is of benefit for further optimization and scale-up of the bioreactor for treatment of paint stripping and other volatile organic wastes in bulk materials.

In vitro and in vivo evaluation of diamond-coated strips.

PubMed

Lione, Roberta; Gazzani, Francesca; Pavoni, Chiara; Guarino, Stefano; Tagliaferri, Vincenzo; Cozza, Paola

2017-05-01

To test in vitro and in vivo the wear performance of diamond-coated strips by means of tribological testing and scanning electronic microscope (SEM). To evaluate the in vitro wear performance, a tribological test was performed by a standard tribometer. The abrasive strips slid against stationary, freshly extracted premolars fixed in resin blocks, at a 2-newton load. At the end of the tribological test, the residual surface of the strip was observed by means of SEM analysis, which was performed every 50 meters until reaching 300 meters. For the in vivo analysis, the strip was used for 300 seconds, corresponding to 250 meters. The strips presented a fenestrated structure characterized by diamond granules alternating with voids. After the first 50 meters, it was possible to observe tooth material deposited on the surface of the strips and a certain number of abrasive grains detached. The surface of the strip after 250 meters appeared smoother and therefore less effective in its abrasive power. After 300 seconds of in vivo utilization of the strip, it was possible to observe the detachment of diamond abrasive grains, the near absence of the grains and, therefore, loss of abrasive power. Under ideal conditions, after 5 minutes (30 meters) of use, the strip loses its abrasive capacity by about 60%. In vivo, a more rapid loss of abrasive power was observed due to the greater load applied by the clinician in forcing the strip into the contact point.

Walk-through survey report: Control of methylene chloride in furniture stripping at jet strip, Boulder, Colorado, August 1, 1991

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

Hall, R.M.; Sheehy, J.W.

1992-12-01

A walk through survey was made of the furniture stripping process at Jet Strip (SIC-7641), Boulder, Colorado to examine the effectiveness of a unique, enclosed, automated furniture stripping spray system which featured a gasket sealed lid which was in place while furniture was being stripped. Stripping was performed continuously throughout the workday. The enclosed spray system tank was 6 feet wide, 10 feet long and 4.5 feet deep. Furniture to be stripped was placed on a metal grid hung from the top of the enclosed spray system. The rack was lowered into the tank and the lip dropped to formmore » the cover of the enclosed system. A hole in the lid was connected to a water bed mattress which lays on top of the lip. During the stripping process, vapors were emitted through the hole, causing the mattress to expand. At the completion of the stripping process the vapors slowly dissipated into the tank, leaving the mattress in its original form. A single personal sample collected during the stripping and rinsing operations showed a methylene-chloride concentration of 68 parts per million (ppm). If the rinse area were also controlled, the enclosed system could keep the concentration below the 25ppm level. The system was homemade and not commercially available. The authors conclude that the system, while apparently effective, was also expensive. It is not recommended for further study at this time.« less

Application of DNA Aptamers and Quantum Dots to Lateral Flow Test Strips for Detection of Foodborne Pathogens with Improved Sensitivity versus Colloidal Gold

PubMed Central

Bruno, John G.

2014-01-01

Preliminary studies aimed at improving the sensitivity of foodborne pathogen detection via lateral flow (LF) test strips by use of high affinity DNA aptamers for capture and reporter functions when coupled to red-emitting quantum dots (Qdot 655) are reported. A variety of DNA aptamers developed against Escherichia coli, Listeria monocytogenes, and Salmonella enterica were paired in capture and reporter combinations to determine which yielded the strongest detection of their cognate bacteria using a colloidal gold screening system. Several promising sandwich combinations were identified for each of the three bacterial LF strip systems. The best E. coli aptamer-LF system was further studied and yielded a visible limit of detection (LOD) of ~3,000 E. coli 8739 and ~6,000 E. coli O157:H7 in buffer. These LODs were reduced to ~300–600 bacterial cells per test respectively by switching to a Qdot 655 aptamer-LF system. Novel aspects of these assays such as the use of high levels of detergents to avoid quantum dot agglutination and enhance migration in analytical membranes, identification of optimal analytical membrane types, UV-immobilization of capture aptamers, and novel dual biotin/digoxigenin-end labeled aptamer streptavidin-colloidal gold or -Qdot 655 conjugates plus anti-digoxigenin antibody control lines are also discussed. In general, this work provides proof-of-principle for highly sensitive aptamer-Qdot LF strip assays for rapid foodborne pathogen detection. PMID:25437803

Novel cellulose-based halochromic test strips for naked-eye detection of alkaline vapors and analytes.

PubMed

Abou-Yousef, Hussein; Khattab, Tawfik A; Youssef, Yehia A; Al-Balakocy, Naser; Kamel, Samir

2017-08-01

A simple, portable and highly sensitive naked-eye test strip is successfully prepared for optical detection of gaseous and aqueous alkaline analytes. Novel pH-sensory tricyanofuran-hydrazone (TCFH) disperse colorant containing a hydrazone recognition functional moiety is successfully synthesized via azo-coupling reaction between active methyl-containing tricyanofuran (TCF) heterocycle and diazonium salt of 4-aminobenzaldehyde followed by Knoevenagel condensation with malononitrile. UV-vis absorption spectra display solvatochromism and reversible color changes of the TCFH solution in dimethyl sulfoxide in response to pH variations. We investigate the preparation of hydrophobic cellulose/polyethylene terephthalate composites characterized by their high affinity for disperse dyes. Composite films made from CA, Cell/CA, PET/CA, and Cell/PET-CA are produced via solvent-casting procedure using 10-30% modified cellulose or modified polyethylene terephthalate. The mechanical properties and morphologies of these composite films are investigated. The prepared pH-sensory hydrazone-based disperse dye is then applied to dye the produced cellulose-based composite films employing the high temperature pressure dyeing procedure. The produced halochromic PET-CA-TCFH test strip provide an instant visible signal from orange to purple upon exposure to alkaline conditions as proved by the coloration measurements. The sensor strip exhibits high sensitivity and quick detection toward ammonia in both of aqueous and vapor phases by naked-eye observations at room temperature and atmospheric pressure. Copyright © 2017 Elsevier B.V. All rights reserved.

Chronic levothyroxine and acute T3 treatments enhance the amplitude and time course of uterine contractions in human.

PubMed

Corriveau, Stéphanie; Pasquier, Jean-Charles; Blouin, Simon; Bellabarba, Diego; Rousseau, Éric

2013-03-01

This study compares the functional consequences of levothyroxine (T4) treatment during pregnancy as well as the acute affects of triiodothyronine (T3) on spontaneous uterine contractile activities observed in vitro. Uterine biopsies were obtained from consenting women undergoing elective caesarean at term (n = 28). Spontaneous contractile activities from T4-treated pregnant women (n = 8) were compared with control patients (n = 20) by isometric tension measurements. Effects of acute T3 and T4 on control tissues were also monitored. Area under the curve, amplitude, time to peak, duration, and frequency were quantified. In uterine strips from women treated for hypothyroidism, phasic uterine contractions of larger amplitude (+77%) were observed, with a prolonged duration at 90% relaxation (+138%) and reduced frequency (-55%) compared with values of the control group. The addition of exogenous T3 in vitro on control strips induced a significant increase in the duration of the contractions and a significant decrease in frequency (P < 0.05), which partially mimics the results obtained in strips from T4-treated women. Significant modifications of contractile properties were observed in strips from pregnant women treated with levothyroxine, consistent with those observed with the addition of exogenous T3. Clinical practices of modern obstetrics should take into account the effect of thyroid hormones on uterine contractions' time course to ensure a tighter followup at the end of pregnancy to achieve safer delivery.

Computational Implementation of a Thermodynamically Based Work Potential Model For Progressive Microdamage and Transverse Cracking in Fiber-Reinforced Laminates

NASA Technical Reports Server (NTRS)

Pineda, Evan J.; Waas, Anthony M.; Bednarcyk, Brett A.; Collier, Craig S.

2012-01-01

A continuum-level, dual internal state variable, thermodynamically based, work potential model, Schapery Theory, is used capture the effects of two matrix damage mechanisms in a fiber-reinforced laminated composite: microdamage and transverse cracking. Matrix microdamage accrues primarily in the form of shear microcracks between the fibers of the composite. Whereas, larger transverse matrix cracks typically span the thickness of a lamina and run parallel to the fibers. Schapery Theory uses the energy potential required to advance structural changes, associated with the damage mechanisms, to govern damage growth through a set of internal state variables. These state variables are used to quantify the stiffness degradation resulting from damage growth. The transverse and shear stiffness of the lamina are related to the internal state variables through a set of measurable damage functions. Additionally, the damage variables for a given strain state can be calculated from a set of evolution equations. These evolution equations and damage functions are implemented into the finite element method and used to govern the constitutive response of the material points in the model. Additionally, an axial failure criterion is included in the model. The response of a center-notched, buffer strip-stiffened panel subjected to uniaxial tension is investigated and results are compared to experiment.

Software Tools for Developing and Simulating the NASA LaRC CMF Motion Base

NASA Technical Reports Server (NTRS)

Bryant, Richard B., Jr.; Carrelli, David J.

2006-01-01

The NASA Langley Research Center (LaRC) Cockpit Motion Facility (CMF) motion base has provided many design and analysis challenges. In the process of addressing these challenges, a comprehensive suite of software tools was developed. The software tools development began with a detailed MATLAB/Simulink model of the motion base which was used primarily for safety loads prediction, design of the closed loop compensator and development of the motion base safety systems1. A Simulink model of the digital control law, from which a portion of the embedded code is directly generated, was later added to this model to form a closed loop system model. Concurrently, software that runs on a PC was created to display and record motion base parameters. It includes a user interface for controlling time history displays, strip chart displays, data storage, and initializing of function generators used during motion base testing. Finally, a software tool was developed for kinematic analysis and prediction of mechanical clearances for the motion system. These tools work together in an integrated package to support normal operations of the motion base, simulate the end to end operation of the motion base system providing facilities for software-in-the-loop testing, mechanical geometry and sensor data visualizations, and function generator setup and evaluation.

Possible role of bioactive peptides in the regulation of human detrusor smooth muscle - functional effects in vitro and immunohistochemical presence.

PubMed

Uckert, Stefan; Stief, Christian G; Lietz, Burckhard; Burmester, Martin; Jonas, Udo; Machtens, Stefan A

2002-09-01

Results from basic research implicate a role for bioactive peptides in controlling the mammalian lower urinary tract. Although various peptides are assumed to be involved in the potentiaton or inhibition of cholinergic or purinergic activity in the urinary bladder, there is still much controversy regarding the mode of action and functional significance of such peptides in detrusor smooth muscle. Thus, we evaluated the functional effects of atrial natriuretic peptide (ANP), calcitonin gene related peptide (CGRP), endothelin 1 (ET-1), substance P (SP) and vasoactive intestinal polypeptide (VIP) on isolated strip preparations of human detrusor smooth muscle and determined the presence of those peptides in the human detrusor by means of immunohistochemistry. The effects of peptides on isometric tension of isolated detrusor strip preparations and on tissue levels of cyclic nucleotides cAMP and cGMP were compared to those of adenylyl cyclase activator forskolin (F), nitric oxide donor Na(+)-nitroprusside (SNP) and non-specific phosphodiesterase (PDE) inhibitor papaverine (P). The effects of the compounds on isometric tension of isolated human detrusor smooth muscle were examined using the organ bath technique. To determine time- and dose-dependent effects on cyclic nucleotide levels, bladder strips were exposed to increasing doses of F, SNP, P, ANP, CGRP and VIP, then rapidly frozen in liquid nitrogen and homogenised in the frozen state. cAMP and cGMP were extracted and assayed using specific radioimmunoassays. The presence of peptides was investigated by light microscopy using the Avidin-Biotin-Complex (ABC) method. F, P and VIP most effectively reversed the carbachol-induced tension of isolated human detrusor strips. Relaxing effects of ANP, CGRP and SNP were negligible. In contrast, ET-1 and SP elicited dose-dependent contractions of the tissue. The relaxing effects of F, P and VIP were accompanied by an increase in cAMP and cGMP levels, respectively. Light microscopy revealed positive immunostaining for CGRP, ET 1, VIP and SP in sections of the detrusor muscle coat. Our results suggest a possible importance of ET 1, SP and VIP in regulating detrusor smooth muscle contraction and relaxation. Even if a peptide is not synthesised, stored or released in a smooth muscle tissue and is, therefore, unable to reach its target cells under physiologic conditions, a functional effect on the tissue might be mediated by peptide-binding to specific cell surface receptors.

Single-Axis Accelerometer

NASA Technical Reports Server (NTRS)

Tucker, Dennis Stephen (Inventor); Capo-Lugo, Pedro A. (Inventor)

2016-01-01

A single-axis accelerometer includes a housing defining a sleeve. An object/mass is disposed in the sleeve for sliding movement therein in a direction aligned with the sleeve's longitudinal axis. A first piezoelectric strip, attached to a first side of the object and to the housing, is longitudinally aligned with the sleeve's longitudinal axis. The first piezoelectric strip includes a first strip of a piezoelectric material with carbon nanotubes substantially aligned along a length thereof. A second piezoelectric strip, attached to a second side of the object and to the housing, is longitudinally aligned with the sleeve's longitudinal axis. The second piezoelectric strip includes a second strip of the piezoelectric material with carbon nanotubes substantially aligned along a length thereof. A voltage sensor is electrically coupled to at least one of the first and second piezoelectric strips.

Augmentation with a reinforced acellular fascia lata strip graft limits cyclic gapping of supraspinatus repairs in a human cadaveric model.

PubMed

Milks, Ryan A; Kolmodin, Joel D; Ricchetti, Eric T; Iannotti, Joseph P; Derwin, Kathleen A

2018-06-01

A reinforced biologic strip graft was designed to mechanically augment the repair of rotator cuff tears that are fully reparable by arthroscopic techniques yet have a likelihood of failure. This study assessed the extent to which augmentation of human supraspinatus repairs with a reinforced fascia strip can reduce gap formation during in vitro cyclic loading. The supraspinatus tendon was sharply released from the proximal humerus and repaired back to its insertion with anchors in 9 matched pairs of human cadaveric shoulders. One repair from each pair was also augmented with a reinforced fascia strip. All repairs were subjected to cyclic mechanical loading of 5 to 180 N for 1000 cycles. All augmented and nonaugmented repair constructs completed 1000 cycles of loading. Augmentation with a reinforced fascia strip graft significantly decreased the amount of gap formation compared with nonaugmented repairs. The average gap formation of augmented repairs was 1.5 ± 0.7 mm after the first cycle vs. 3.0 ± 1.2 mm for nonaugmented repairs (P = .003) and 5.0 ± 1.5 mm after 1000 cycles of loading, which averaged 24% ± 21% less than the gap formation of nonaugmented repairs (7.0 ± 2.8 mm, P = .014). Cadaveric human supraspinatus repairs augmented with a reinforced fascia strip have significantly less initial stroke elongation and gap formation than repairs without augmentation. Augmentation limited gap formation to the greatest extent early in the testing protocol. Human studies are necessary to confirm the appropriate indications and effectiveness of augmentation scaffolds for rotator cuff repair healing in the clinical setting. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Glucose meters: evaluation of the new formulation measuring strips from Roche (Accu-Chek) and Abbott (MediSense).

PubMed

Dimeski, G; Jones, B W; Tilley, V; Greenslade, M N; Russell, A W

2010-07-01

Both Roche and Abbott have released new glucose meter strips. They supply the entire Australian hospital market. The present study compared the performance of the new strips utilizing various specimen types (capillary, venous lithium heparin whole blood, venous lithium heparin plasma and serum) and evaluated how well they comply with the International Standards Organization (ISO) 15197 criteria. The study included imprecision, patient comparison and interference studies. Participants with and without diabetes were recruited to evaluate the performance of various specimen types against the Beckman DxC800 glucose method. The strips were tested for different interferences: galactose, maltose, lactose, Icodextrin, Intragam, paracetamol, sodium, ascorbic acid, variable strip storage temperature, haematocrit, haemolysis and lipaemia. The imprecision of the two strips was approximately 5% or less, except for the Abbott strip at very low values (1.4 mmol/L), approximately 7%. In total, 78% and 84%, respectively, of the results from the finger prick capillary specimens with the Roche (Accu-Chek Performa meter) and Abbott (Optium Xceed meter) strips, not 95% or greater as recommended by the ISO guideline, were within the recommended limits compared with reference plasma estimation on laboratory analysers. Galactose, ascorbic acid, haematocrit and sodium on the Roche and ascorbic acid and haematocrit on the Abbott strip continue to interfere to a variable degree with the glucose measurement. Analytically small differences exist between the glucose meter strips. The most significant analytical difference with the strips was at low glucose levels when compared with laboratory analyses and this may be of clinical importance. The impact of some of the interferences is variable between the two strips. Individuals, health-care professionals and health-care institutions should consider these data when selecting glucose meters for the management of people with diabetes mellitus.

Occultation Predictions Using CCD Strip-Scanning Astrometry

NASA Technical Reports Server (NTRS)

Dunham, Edward W.; Ford, C. H.; Stone, R. P. S.; McDonald, S. W.; Olkin, C. B.; Elliot, J. L.; Witteborn, Fred C. (Technical Monitor)

1994-01-01

We are developing the method of CCD strip-scanning astrometry for the purpose of deriving reliable advance predictions for occultations involving small objects in the outer solar system. We are using a camera system based on a Ford/Loral 2Kx2K CCD with the Crossley telescope at Lick Observatory for this work. The columns of die CCD are aligned East-West, the telescope drive is stopped, and the CCD is clocked at the same rate that the stars drift across it. In this way we obtain arbitrary length strip images 20 arcmin wide with 0.58" pixels. Since planets move mainly in RA, it is possible to obtain images of the planet and star to be occulted on the same strip well before the occultation occurs. The strip-to-strip precision (i.e. reproducibility) of positions is limited by atmospheric image motion to about 0.1" rms per strip. However, for objects that are nearby in R.A., the image motion is highly correlated and their relative positions are good to 0.02" rms per strip. We will show that the effects of atmospheric image motion on a given strip can be removed if a sufficient number of strips of a given area have been obtained. Thus, it is possible to reach an rms precision of 0.02" per strip, corresponding to about 0.3 of Pluto or Triton's angular radius. The ultimate accuracy of a prediction based on strip-scanning astrometry is currently limited by the accuracy of the positions of the stars in the astrometric network used and by systematic errors most likely due to the optical system. We will show the results of . the prediction of some recent occultations as examples of the current capabilities and limitations of this technique.

Validity of HydraTrend reagent strips for the assessment of hydration status.

PubMed

Abbey, Bryce M; Heelan, Kate A; Brown, Gregory A; Bartee, Rodrick T

2014-09-01

Hydration is used by athletic governing organizations for weight class eligibility. The measurement of urine specific gravity (USG) as a measure of hydration by reagent strips is a controversial issue. The purpose of this study was to determine the validity of HydraTrend reagent strips that facilitate the correction of USG for alkaline urine samples against refractometry for the assessment of USG. Fifty-one participants (33 males, age = 22.3 ± 1.3 years; 18 females, age = 22.4 ± 1.2 years) provided 84 urine samples. The samples were tested for USG using refractometry and reagent strips and for pH using reagent strips and a digital pH meter. Strong correlation coefficients were found between refractometry and reagent strips for USG (rs(82) = 0.812, p < 0.01) and between reagent strips and pH meter for pH (rs(82) = 0.939, p < 0.01). It was observed that false negative results for National Collegiate Athletic Association (NCAA) requirements (fail refractometry with USG >1.020, pass reagent strips with USG ≤1.020) occurred 39% (33/84) of the time and false negative results for National Federation of State High School Association (NFHS) requirements (fail refractometry with USG >1.025, pass reagent strips with USG ≤1.025) occurred 14% (12/84) of the time. There were no false positives (pass refractometry and fail reagent strips) for NCAA or NFHS requirements. These data show that refractometry and reagent strips have strong positive correlations. However, the risk of a false negative result leading to incorrect certification of euhydration status outweighs the benefits of the HydraTrend reagent strips for the measurement of USG.

Development of a Combined Human Transferrin-Hemoglobin Lateral Immunochromatographic Assay for Accurate and Rapid Fecal Occult Blood Test.

PubMed

Ye, Yuanyuan; Deng, Yin; Mao, Jinju; Yan, Qin; Huang, Yidan; Zhang, Jun; Zheng, Jian; Li, Yue; Chen, Weixian

2018-05-01

Fecal occult bloodtest (FOBT) plays an important role in the diagnosis of gastrointestinal diseases. The sensitivities of current FOBT methods are still not satisfactory. The aim of this study is to develop a combined human transferrin (HTf)-hemoglobin (HHb) lateral flow assay (LFA) for accurate and rapid FOBT. Monoclonal antibodies (MAbs) targeting HTf were developed by conventional methods and paired using LFA strips. The best HTf MAb pair was chosen according to the overall performance on testing limit and specificity. Meanwhile, HHb LFA strips were prepared using previously developed HHb MAbs. The testing limit and specificity were characterized. Based on the selected HTf MAb pair and the verified HHb MAb pair, combined HTf-HHb strips were developed. The combined HTf-HHb strips were used for FOBT of 400 human fecal samples, including 200 gastrointestinal bleeding specimens and 200 healthy subjects. For comparison, the homemade individual HTf and HHb strips, as well as three kinds of commercial FOBT strips, were also used for the FOBT. Two MAb pairs targeting HTf were developed for LFA. Two types of HTf strips were prepared accordingly. The type I was chosen due to its lower detection limit. Using the type I HTf MAb pair and the verified HHb- MAb pair, the combined HTf-HHb strips could detect the HTf at concentrations between 1 ng/mL and 1 x 106 ng/mL and the HHb between 10 ng/mL and 2.5 x 106 ng/mL. Compared to individual HTf and HHb strips and three kinds of commercial strips, the combined strips showed the highest diagnostic sensitivity in FOBT (96.0%). The specificity was a satisfactory 99%. Our combined HTf-HHb test strips are a very promising product for accurate and rapid FOBT.

Chemosensory interaction: acquired olfactory impairment is associated with decreased taste function.

PubMed

Landis, Basile N; Scheibe, Mandy; Weber, Cornelia; Berger, Robert; Brämerson, Annika; Bende, Mats; Nordin, Steven; Hummel, Thomas

2010-08-01

Olfaction, taste and trigeminal function are three distinct modalities. However, in daily life they are often activated concomitantly. In health and disease, it has been shown that in two of these senses, the trigeminal and olfactory senses, modification of one sense leads to changes in the other sense and vice versa. The objective of the study was to investigate whether and (if so) how, the third modality, taste, is influenced by olfactory impairment. We tested 210 subjects with normal (n = 107) or impaired (n = 103) olfactory function for their taste identification capacities. Validated tests were used for olfactory and gustatory testing (Sniffin' Sticks, Taste Strips). In an additional experiment, healthy volunteers underwent reversible olfactory cleft obstruction to investigate short-time changes of gustatory function after olfactory alteration. Mean gustatory identification (taste strip score) for the subjects with impaired olfaction was 19.4 +/- 0.6 points and 22.9 +/- 0.5 points for those with normal olfactory function (t = 4.6, p < 0.001). The frequencies of both, smell and taste impairments interacted significantly (Chi(2), F = 16.4, p < 0.001), and olfactory and gustatory function correlated (r (210) = 0.30, p < 0.001). Neither age nor olfactory impairment cause effects interfered with this olfactory-gustatory interaction. In contrast, after short-lasting induced olfactory decrease, gustatory function remained unchanged. The present study suggests that longstanding impaired olfactory function is associated with decreased gustatory function. These findings seem to extend previously described mutual chemosensory interactions also to smell and taste. It further raises the question whether chemical senses in general decrease mutually after acquired damage.

Early presymptomatic cholinergic dysfunction in a murine model of amyotrophic lateral sclerosis

PubMed Central

Casas, Caty; Herrando-Grabulosa, Mireia; Manzano, Raquel; Mancuso, Renzo; Osta, Rosario; Navarro, Xavier

2013-01-01

Sporadic and familiar amyotrophic lateral sclerosis (ALS) cases presented lower cholinergic activity than in healthy individuals in their still preserved spinal motoneurons (MNs) suggesting that cholinergic reduction might occur before MN death. To unravel how and when cholinergic function is compromised, we have analyzed the spatiotemporal expression of choline acetyltransferase (ChAT) from early presymptomatic stages of the SOD1G93A ALS mouse model by confocal immunohistochemistry. The analysis showed an early reduction in ChAT content in soma and presynaptic boutons apposed onto MNs (to 76%) as well as in cholinergic interneurons in the lumbar spinal cord of the 30-day-old SOD1G93A mice. Cholinergic synaptic stripping occurred simultaneously to the presence of abundant surrounding major histocompatibility complex II (MHC-II)-positive microglia and the accumulation of nuclear Tdp-43 and the appearance of mild oxidative stress within MNs. Besides, there was a loss of neuronal MHC-I expression, which is necessary for balanced synaptic stripping after axotomy. These events occurred before the selective raise of markers of denervation such as ATF3. By the same time, alterations in postsynaptic cholinergic-related structures were also revealed with a loss of the presence of sigma-1 receptor, a Ca2+ buffering chaperone in the postsynaptic cisternae. By 2 months of age, ChAT seemed to accumulate in the soma of MNs, and thus efferences toward Renshaw interneurons were drastically diminished. In conclusion, cholinergic dysfunction in the local circuitry of the spinal cord may be one of the earliest events in ALS etiopathogenesis. PMID:23531559

Rolled-up transformer structure for a radiofrequency integrated circuit (RFIC)

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

Li, Xiuling; Huang, Wen

A rolled-up transformer structure comprises a multilayer sheet having a rolled configuration comprising multiple turns about a longitudinal axis. The multilayer sheet comprises more than one conductive pattern layer on a strain-relieved layer, including a first conductive film and a second conductive film separated from the first conductive film in a thickness direction. The first conductive film comprises an even number of primary conductive strips, where each primary conductive strip has a length extending in the rolling direction, and the second conductive film comprises an even number of secondary conductive strips, where each secondary conductive strip has a length extendingmore » in the rolling direction. In the rolled configuration, turns of the primary conductive strips and turns of the secondary conductive strips wrap around the longitudinal axis. The primary conductive strips serve as a primary winding and the secondary conductive strips serve as a secondary winding of the rolled-up transformer structure.« less

HIGH FREQUENCY POWER TRANSMISSION LINE FOR CYCLOTRONS AND THE LIKE

DOEpatents

Armstrong, W.J.

1954-04-20

High-frequency power transmission systems, particularly a stacked capacitance alternating power current transmission line wherein maximum utilization of the effective conductios skin of the line conductors is achieved while enabling a low impedance to be obtained are reported. The transmission line consists of a number of flat metal strips with interleaved dielectric strips. The metal dielectric strips are coiled spirally with the axis of the spiral extending along the length of the strips, and the alternating metal strips at the output end have outwardly extending aligned lugs which are directly strapped together and connected to the respective terminals on the load. At the input end of the transmission line, similarly, the alternate metal strips are directly strapped together and connected to an altereating current source. With the arrangement described each metal strip conducts on both sides, so that the metal strips are designed to have a thickness corresponding to twice the depth of the "skin effect" conducting lamina of each conductor at the source frequency.

Assessment of sensory function in the National Social Life, Health, and Aging Project.

PubMed

Schumm, L Philip; McClintock, Martha; Williams, Sharon; Leitsch, Sara; Lundstrom, Johan; Hummel, Thomas; Lindau, Stacy Tessler

2009-11-01

The National Social Life, Health, and Aging Project assessed functioning of all 5 senses using both self-report and objective measures. We evaluate the performance of the objective measures and model differences in sensory function by gender and age. In the process, we demonstrate how to use and interpret these measures. Distance vision was assessed using a standard Sloan eye chart, and touch was measured using a stationary 2-point discrimination test applied to the index fingertip of the dominant hand. Olfactory function (both intensity detection and odor identification) was assessed using odorants administered via felt-tip pens. Gustatory function was measured via identification of four taste strips. The performance of the objective measures was similar to that reported for previous studies, as was the relationship between sensory function and both gender and age. Sensory function is important in studies of aging and health both because it is an important health outcome and also because a decline in functioning can be symptomatic of or predict other health conditions. Although the objective measures provide considerably more precision than the self-report items, the latter can be valuable for imputation of missing data and for understanding differences in how older adults perceive their own sensory ability.

Assessment of Sensory Function in the National Social Life, Health, and Aging Project

PubMed Central

McClintock, Martha; Williams, Sharon; Leitsch, Sara; Lundstrom, Johan; Hummel, Thomas; Lindau, Stacy Tessler

2009-01-01

Objectives The National Social Life, Health, and Aging Project assessed functioning of all 5 senses using both self-report and objective measures. We evaluate the performance of the objective measures and model differences in sensory function by gender and age. In the process, we demonstrate how to use and interpret these measures. Methods Distance vision was assessed using a standard Sloan eye chart, and touch was measured using a stationary 2-point discrimination test applied to the index fingertip of the dominant hand. Olfactory function (both intensity detection and odor identification) was assessed using odorants administered via felt-tip pens. Gustatory function was measured via identification of four taste strips. Results The performance of the objective measures was similar to that reported for previous studies, as was the relationship between sensory function and both gender and age. Discussion Sensory function is important in studies of aging and health both because it is an important health outcome and also because a decline in functioning can be symptomatic of or predict other health conditions. Although the objective measures provide considerably more precision than the self-report items, the latter can be valuable for imputation of missing data and for understanding differences in how older adults perceive their own sensory ability. PMID:19549923

Performance optimization of helicopter rotor blades

NASA Technical Reports Server (NTRS)

Walsh, Joanne L.

1991-01-01

As part of a center-wide activity at NASA Langley Research Center to develop multidisciplinary design procedures by accounting for discipline interactions, a performance design optimization procedure is developed. The procedure optimizes the aerodynamic performance of rotor blades by selecting the point of taper initiation, root chord, taper ratio, and maximum twist which minimize hover horsepower while not degrading forward flight performance. The procedure uses HOVT (a strip theory momentum analysis) to compute the horse power required for hover and the comprehensive helicopter analysis program CAMRAD to compute the horsepower required for forward flight and maneuver. The optimization algorithm consists of the general purpose optimization program CONMIN and approximate analyses. Sensitivity analyses consisting of derivatives of the objective function and constraints are carried out by forward finite differences. The procedure is applied to a test problem which is an analytical model of a wind tunnel model of a utility rotor blade.

Biomechanical measurements of stopping and stripping torques during screw insertion in five types of human and artificial humeri.

PubMed

Aziz, Mina Sr; Tsuji, Matthew Rs; Nicayenzi, Bruce; Crookshank, Meghan C; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Radovan

2014-05-01

During orthopedic surgery, screws are inserted by "subjective feel" in humeri for fracture fixation, that is, stopping torque, while trying to prevent accidental over-tightening that causes screw-bone interface failure, that is, stripping torque. However, no studies exist on stopping torque, stripping torque, or stopping/stripping torque ratio in human or artificial humeri. This study evaluated five types of humeri, namely, human fresh-frozen (n = 19), human embalmed (n = 18), human dried (n = 15), artificial "normal" (n = 13), and artificial "osteoporotic" (n = 13). An orthopedic surgeon used a torque screwdriver to insert 3.5-mm-diameter cortical screws into humeral shafts and 6.5-mm-diameter cancellous screws into humeral heads by "subjective feel" to obtain stopping and stripping torques. The five outcome measures were raw and normalized stopping torque, raw and normalized stripping torque, and stopping/stripping torque ratio. Normalization was done as raw torque/screw-bone interface area. For "gold standard" fresh-frozen humeri, cortical screw tests yielded averages of 1312 N mm (raw stopping torque), 30.4 N/mm (normalized stopping torque), 1721 N mm (raw stripping torque), 39.0 N/mm (normalized stripping torque), and 82% (stopping/stripping torque ratio). Similarly, fresh-frozen humeri gave cancellous screw average results of 307 N mm (raw stopping torque), 0.9 N/mm (normalized stopping torque), 392 N mm (raw stripping torque), 1.2 N/mm (normalized stripping torque), and 79% (stopping/stripping torque ratio). Of the five cortical screw parameters for fresh-frozen humeri versus other groups, statistical equivalence (p ≥ 0.05) occurred in four cases (embalmed), three cases (dried), four cases (artificial "normal"), and four cases (artificial "osteoporotic"). Of the five cancellous screw parameters for fresh-frozen humeri versus other groups, statistical equivalence (p ≥ 0.05) occurred in five cases (embalmed), one case (dried), one case (artificial "normal"), and zero cases (artificial "osteoporotic"). Stopping/stripping torque ratios were relatively constant for all groups at 77%-88% (cortical screws) and 79%-92% (cancellous screws). © IMechE 2014.

Agricultural conservation practices can help mitigate the impact of climate change.

PubMed

Wagena, Moges B; Easton, Zachary M

2018-09-01

Agricultural conservation practices (CPs) are commonly implemented to reduce diffuse nutrient pollution. Climate change can complicate the development, implementation, and efficiency of agricultural CPs by altering hydrology, nutrient cycling, and erosion. This research quantifies the impact of climate change on hydrology, nutrient cycling, erosion, and the effectiveness of agricultural CP in the Susquehanna River Basin in the Chesapeake Bay Watershed, USA. We develop, calibrate, and test the Soil and Water Assessment Tool-Variable Source Area (SWAT-VSA) model and select four CPs; buffer strips, strip-cropping, no-till, and tile drainage, to test their effectiveness in reducing climate change impacts on water quality. We force the model with six downscaled global climate models (GCMs) for a historic period (1990-2014) and two future scenario periods (2041-2065 and 2075-2099) and quantify the impact of climate change on hydrology, nitrate-N (NO 3 -N), total N (TN), dissolved phosphorus (DP), total phosphorus (TP), and sediment export with and without CPs. We also test prioritizing CP installation on the 30% of agricultural lands that generate the most runoff (e.g., critical source areas-CSAs). Compared against the historical baseline and with no CPs, the ensemble model predictions indicate that climate change results in annual increases in flow (4.5±7.3%), surface runoff (3.5±6.1%), sediment export (28.5±18.2%) and TN export (9.5±5.1%), but decreases in NO 3 -N (12±12.8%), DP (14±11.5), and TP (2.5±7.4%) export. When agricultural CPs are simulated most do not appreciably change the water balance, however, tile drainage and strip-cropping decrease surface runoff, sediment export, and DP/TP, while buffer strips reduce N export. Installing CPs on CSAs results in nearly the same level of performance for most practices and most pollutants. These results suggest that climate change will influence the performance of agricultural CPs and that targeting agricultural CPs to CSAs can provide nearly the same level of water quality effects as more widespread adoption. Copyright © 2018 Elsevier B.V. All rights reserved.

The knockout reaction of {sup 15}C on a {sup 9}Be target at intermediate energies

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

Sadeghi, H., E-mail: H-Sadeghi@araku.ac.ir; Fereidonnejad, R.; Ghambari, M.

2016-05-15

In this work, neutron knockout reactions of {sup 15}C on a {sup 9}Be target at energy 103 and 250 MeV/nucleon are studied. Using the Eikonal approximation of the Glauber model, total neutron removal cross sections, the stripping and diffractive cross sections as well as {sup 14}C longitudinal momentum distributions are determined in both {sup 15}C ground state and exited states of the wave function. We compared the results of our calculations with the available experimental data obtained recently. The calculated cross sections of {sup 15}C and {sup 14}C reactions, as well as the momentum distribution are in relatively good agreementmore » with available data.« less

Analysis of a hybrid, unidirectional buffer strip laminate

NASA Technical Reports Server (NTRS)

Dharani, L. R.; Goree, J. G.

1983-01-01

A method of analysis capable of predicting accurately the fracture behavior of a unidirectional composite laminate containing symmetrically placed buffer strips is presented. As an example, for a damaged graphite/epoxy laminate, the results demonstrate the manner in which to select the most efficient combination of buffer strip properties necessary to inhibit crack growth. Ultimate failure of the laminate after crack arrest can occur under increasing load either by continued crack extension through the buffer strips or the crack can jump the buffer strips. For some typical hybrid materials it is found that a buffer strip spacing-to-width ratio of about four to one is the most efficient.

Enhanced absorption of graphene strips with a multilayer subwavelength grating structure

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

Hu, Jin-Hua; Huang, Yong-Qing, E-mail: yqhuang@bupt.edu.cn; Duan, Xiao-Feng

2014-12-01

The optical absorption of graphene strips covered on a multilayer subwavelength grating (MSG) surface is theoretically investigated. The absorption of graphene strips with MSG is enhanced in the wavelength range of 1500 nm to 1600 nm by critical coupling, which is associated with the combined effects of a guided resonance of MSG and its photonic band gap effect. The critical coupling of the graphene strips can be controlled by adjusting the incident angle without changing the structural parameters of MSG. The absorption of graphene strips can also be tuned by varying key parameters, such as grating period, strip width, and incident angle.

Analysis of a hybrid-undirectional buffer strip laminate

NASA Technical Reports Server (NTRS)

Dharani, L. R.; Goree, J. G.

1983-01-01

A method of analysis capable of predicting accurately the fracture behavior of a unidirectional composite laminate containing symmetrically placed buffer strips is presented. As an example, for a damaged graphite/epoxy laminate, the results demonstrate the manner in which to select the most efficient combination of buffer strip properties necessary to inhibit crack growth. Ultimate failure of the laminate after the arrest can occur under increasing load either by continued crack extension through the buffer strips or the crack can jump the buffer strips. For some typical hybrid materials it is found that a buffer strip spacing to width ratio of about four to one is the most efficient.

High effectiveness of tailored flower strips in reducing pests and crop plant damage.

PubMed

Tschumi, Matthias; Albrecht, Matthias; Entling, Martin H; Jacot, Katja

2015-09-07

Providing key resources to animals may enhance both their biodiversity and the ecosystem services they provide. We examined the performance of annual flower strips targeted at the promotion of natural pest control in winter wheat. Flower strips were experimentally sown along 10 winter wheat fields across a gradient of landscape complexity (i.e. proportion non-crop area within 750 m around focal fields) and compared with 15 fields with wheat control strips. We found strong reductions in cereal leaf beetle(CLB) density (larvae: 40%; adults of the second generation: 53%) and plant damage caused by CLB (61%) in fields with flower strips compared with control fields. Natural enemies of CLB were strongly increased in flower strips and in part also in adjacent wheat fields. Flower strip effects on natural enemies, pests and crop damage were largely independent of landscape complexity(8-75% non-crop area). Our study demonstrates a high effectiveness of annual flower strips in promoting pest control, reducing CLB pest levels below the economic threshold. Hence, the studied flower strip offers a viable alternative to insecticides. This highlights the high potential of tailored agri-environment schemes to contribute to ecological intensification and may encourage more farmers to adopt such schemes.

Emission reduction by multipurpose buffer strips on arable fields.

PubMed

Sloots, K; van der Vlies, A W

2007-01-01

In the area managed by Hollandse Delta, agriculture is under great pressure and the social awareness of the agricultural sector is increasing steadily. In recent years, a stand-still has been observed in water quality, in terms of agrochemicals, and concentrations even exceed the standard. To improve the waterquality a multi-purpose Field Margin Regulation was drafted for the Hoeksche Waard island in 2005. The regulation prescribes a crop-free strip, 3.5 m wide, alongside wet drainage ditches. The strip must be sown with mixtures of grasses, flowers or herbs. No crop protection chemicals or fertilizer may be used on the strips. A total length of approximately 200 km of buffer strip has now been laid. Besides reducing emissions, the buffer strips also stimulate natural pest control methods and encourage local tourism. Finally, the strips should lead to an improvement in the farmers' image. The regulation has proved to be successful. The buffer strips boosted both local tourism and the image of the agricultural sector. Above all, the strips provided a natural shield for emission to surface water, which will lead to an improvement of the water quality and raise the farmers' awareness of water quality and the environment.

Is oxygen availability a limiting factor for in vitro folliculogenesis?

PubMed Central

Sudhakaran, Sam; Barbato, Vincenza; Merolla, Anna; Braun, Sabrina; Di Nardo, Maddalena; Costanzo, Valentina; Ferraro, Raffaele; Iannantuoni, Nicola

2018-01-01

Transplantation of ovarian tissue for the preservation of fertility in oncological patients is becoming an accepted clinical practice. However, the risk of re-introducing tumour cells at transplantation has stirred an increased interest for complete in vitro folliculogenesis. This has not yet been achieved in humans possibly for the lack of knowledge on the environmental milieu that orchestrates folliculogenesis in vivo. The main aim of this study was to investigate the effect of oxygen availability on follicle health and growth during in vitro culture of ovarian tissue strips. To this end, a model was developed to predict the dissolved oxygen concentration in tissue under varying culture conditions. Ovarian cortical strips of bovine, adopted as an animal model, and human tissue were cultured in conventional (CD) and gas permeable (PD) dishes under different media column heights and gaseous oxygen tensions for 3, 6 and 9 days. Follicle quality, activation of primordial follicles to the primary stage, and progression to the secondary stage were analysed through histology. Follicle viability was assessed through a live-dead assay at the confocal scanning laser microscope. Findings showed a higher follicle quality and viability after culture of bovine ovarian strips in PD in adequate medium height and oxygen tensions. The best culture conditions found in the bovine were adopted for human ovarian strip culture and promoted a higher follicle quality, viability and progression. Overall, data demonstrated that modulation of oxygen availability in tissue plays a key role in maintaining follicles’ health and their ability to survive and progress to the secondary stage during ovarian tissue in vitro culture. Such culture conditions could increase the yield of healthy secondary follicles for subsequent dissection and individual culture to obtain competent oocytes. PMID:29425251

Cracking of a layered medium on an elastic foundation under thermal shock

NASA Technical Reports Server (NTRS)

Rizk, Abd El-Fattah A.; Erdogan, Fazil

1988-01-01

The cladded pressure vessel under thermal shock conditions which is simulated by using two simpler models was studied. The first model (Model 1) assumes that, if the crack size is very small compared to the vessel thickness, the problem can be treated as a semi-infinite elastic medium bonded to a very thin layer of different material. However, if the crack size is of the same order as the vessel thickness, the curvature effects may not be negligible. In this case it is assumed that the relatively thin walled hollow cylinder with cladding can be treated as a composite beam on an elastic foundation (Model 2). In both models, the effect of surface cooling rate is studied by assuming the temperature boundary condition to be a ramp function. The calculated results include the transient temperature, thermal stresses in the uncracked medium and stress intensity factors which are presented as a function of time, and the duration of cooling ramp. The stress intensity factors are also presented as a function of the size and the location of the crack. The problem is solved for two bonded materials of different thermal and mechanical properties. The mathematical formulation results in two singular integral equations which are solved numerically. The results are given for two material pairs, namely an austenitic steel layer welded on a ferritic steel substrate, and a ceramic coating on ferritic steel. In the case of the yielded clad, the stress intensity factors for a crack under the clad are determined by using a plastic strip model and are compared with elastic clad results.

The host dark matter haloes of [O II] emitters at 0.5 < z < 1.5

NASA Astrophysics Data System (ADS)

Gonzalez-Perez, V.; Comparat, J.; Norberg, P.; Baugh, C. M.; Contreras, S.; Lacey, C.; McCullagh, N.; Orsi, A.; Helly, J.; Humphries, J.

2018-03-01

Emission line galaxies (ELGs) are used in several ongoing and upcoming surveys (SDSS-IV/eBOSS, DESI) as tracers of the dark matter distribution. Using a new galaxy formation model, we explore the characteristics of [O II] emitters, which dominate optical ELG selections at z ≃ 1. Model [O II] emitters at 0.5 < z < 1.5 are selected to mimic the DEEP2, VVDS, eBOSS and DESI surveys. The luminosity functions of model [O II] emitters are in reasonable agreement with observations. The selected [O II] emitters are hosted by haloes with Mhalo ≥ 1010.3h-1M⊙, with ˜90 per cent of them being central star-forming galaxies. The predicted mean halo occupation distributions of [O II] emitters have a shape typical of that inferred for star-forming galaxies, with the contribution from central galaxies, < N > _{[O II] cen}, being far from the canonical step function. The < N > _{[O II] cen}} can be described as the sum of an asymmetric Gaussian for discs and a step function for spheroids, which plateau below unity. The model [O II] emitters have a clustering bias close to unity, which is below the expectations for eBOSS and DESI ELGs. At z ˜ 1, a comparison with observed g-band-selected galaxy, which is expected to be dominated by [O II] emitters, indicates that our model produces too few [O II] emitters that are satellite galaxies. This suggests the need to revise our modelling of hot gas stripping in satellite galaxies.

Extraction-Scrub-Strip test results from the interim Salt Disposition Program Macrobatch 9 Tank 21H qualification samples

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

Peters, T.

2016-02-23

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 9 for the Interim Salt Disposition Program (ISDP). The Salt Batch 9 characterization results were previously reported. An Extraction-Scrub-Strip (ESS) test was performed to determine cesium distribution ratios (D (Cs)) and cesium concentration in the strip effluent and decontaminated salt solution (DSS) streams; this data will be used by Tank Farm Engineering to project a cesium decontamination factor (DF). This test used actual Tank 21H material, and a blend solvent prepared by SRNL that mimics the solvent composition currently being used atmore » the Modular Caustic-Side Solvent Extraction Unit (MCU). The ESS test showed acceptable performance with an extraction D (Cs) value of 52.4. This value is consistent with results from previous salt batch ESS tests using similar solvent formulations. This compares well against the predicted value of 56.5 from a recently created D (Cs) model« less

Modeling and simulation of Positron Emission Mammography (PEM) based on double-sided CdTe strip detectors

NASA Astrophysics Data System (ADS)

Ozsahin, I.; Unlu, M. Z.

2014-03-01

Breast cancer is the most common leading cause of cancer death among women. Positron Emission Tomography (PET) Mammography, also known as Positron Emission Mammography (PEM), is a method for imaging primary breast cancer. Over the past few years, PEMs based on scintillation crystals dramatically increased their importance in diagnosis and treatment of early stage breast cancer. However, these detectors have significant limitations like poor energy resolution resulting with false-negative result (missed cancer), and false-positive result which leads to suspecting cancer and suggests an unnecessary biopsy. In this work, a PEM scanner based on CdTe strip detectors is simulated via the Monte Carlo method and evaluated in terms of its spatial resolution, sensitivity, and image quality. The spatial resolution is found to be ~ 1 mm in all three directions. The results also show that CdTe strip detectors based PEM scanner can produce high resolution images for early diagnosis of breast cancer.

Producing thin strips by twin-roll casting—part I: Process aspects and quality issues

NASA Astrophysics Data System (ADS)

Li, Ben Q.

1995-05-01

This two-part paper discusses recent advances in research and development for the direct production of coilable thin strips by twin-roll casting in both the aluminum and steel industries. While the former is empowering the casters to approach the theoretical productivity limit, the latter is striving to put pilot casters into commercial operation. These intensive R&D efforts are derived from the advantages, both economic and metallurgical, offered by the process. As twin-roll casting combines solidification and hot rolling into a single operation, the process requires low capital investment and low operational cost. Also, because of the high solidification rate attained in the process, the thin strips produced have a refined metallurgical structure, characterized by columnar and equiaxed zones with fine intermetallic particles. The enthusiasm about twin-roll casting is now being spread worldwide. This paper focuses on the process aspects and quality control of twin-roll casting. Part II, which will appear in the August issue, will review process modeling and pilot-plant development activities.

Extraction, -scrub, -strip test results from the interim salt disposition program macrobatch 10 tank 21H qualification samples

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

Peters, T. B.

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 10 for the Interim Salt Disposition Program (ISDP). The Salt Batch 10 characterization results were previously reported.ii,iii An Extraction, -Scrub, -Strip (ESS) test was performed to determine cesium distribution ratios (D(Cs)) and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Tank Farm Engineering to project a cesium decontamination factor (DF). This test used actual Tank 21H material, and a sample of the NGS Blend solvent currently being used at the Modularmore » Caustic-Side Solvent Extraction Unit (MCU). The ESS test showed acceptable performance with an extraction D(Cs) value of 110. This value is consistent with results from previous salt batch ESS tests using similar solvent formulations. This is better than the predicted value of 39.8 from a recently created D(Cs) model.« less

Three Temperature Regimes in Superconducting Photon Detectors: Quantum, Thermal and Multiple Phase-Slips as Generators of Dark Counts

PubMed Central

Murphy, Andrew; Semenov, Alexander; Korneev, Alexander; Korneeva, Yulia; Gol’tsman, Gregory; Bezryadin, Alexey

2015-01-01

We perform measurements of the switching current distributions of three w ≈ 120 nm wide, 4 nm thick NbN superconducting strips which are used for single-photon detectors. These strips are much wider than the diameter of the vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We discover evidence of macroscopic quantum tunneling by observing the saturation of the standard deviation of the switching distributions at temperatures around 2 K. We analyze our results using the Kurkijärvi-Garg model and find that the escape temperature also saturates at low temperatures, confirming that at sufficiently low temperatures, macroscopic quantum tunneling is possible in quasi-2D strips and can contribute to dark counts observed in single photon detectors. At the highest temperatures the system enters a multiple phase-slip regime. In this range single phase-slips are unable to produce dark counts and the fluctuations in the switching current are reduced. PMID:25988591

A new failure mechanism in thin film by collaborative fracture and delamination: Interacting duos of cracks

NASA Astrophysics Data System (ADS)

Marthelot, Joël; Bico, José; Melo, Francisco; Roman, Benoît

2015-11-01

When a thin film moderately adherent to a substrate is subjected to residual stress, the cooperation between fracture and delamination leads to unusual fracture patterns, such as spirals, alleys of crescents and various types of strips, all characterized by a robust characteristic length scale. We focus on the propagation of a duo of cracks: two fractures in the film connected by a delamination front and progressively detaching a strip. We show experimentally that the system selects an equilibrium width on the order of 25 times the thickness of the coating and independent of both fracture and adhesion energies. We investigate numerically the selection of the width and the condition for propagation by considering Griffith's criterion and the principle of local symmetry. In addition, we propose a simplified model based on the criterion of maximum of energy release rate, which provides insights of the physical mechanisms leading to these regular patterns, and predicts the effect of material properties on the selected width of the detaching strip.

Design of a shape adaptive airfoil actuated by a Shape Memory Alloy strip for airplane tail

NASA Astrophysics Data System (ADS)

Shirzadeh, R.; Raissi Charmacani, K.; Tabesh, M.

2011-04-01

Of the factors that mainly affect the efficiency of the wing during a special flow regime, the shape of its airfoil cross section is the most significant. Airfoils are generally designed for a specific flight condition and, therefore, are not fully optimized in all flight conditions. It is very desirable to have an airfoil with the ability to change its shape based on the current regime. Shape memory alloy (SMA) actuators activate in response to changes in the temperature and can recover their original configuration after being deformed. This study presents the development of a method to control the shape of an airfoil using SMA actuators. To predict the thermomechanical behaviors of an SMA thin strip, 3D incremental formulation of the SMA constitutive model is implemented in FEA software package ABAQUS. The interactions between the airfoil structure and SMA thin strip actuator are investigated. Also, the aerodynamic performance of a standard airfoil with a plain flap is compared with an adaptive airfoil.

Aptamer-Nanoparticle Strip Biosensor for Rapid and Sensitive Detection of Cancer Cells

PubMed Central

Mao, Xun; Phillips, Joseph A.; Xu, Hui; Tan, Weihong; Zeng, Lingwen; Liu, Guodong

2009-01-01

We report an aptamer-nanoparticle strip biosensor (ANSB) for the rapid, specific, sensitive and low-cost detection of circulating cancer cells. Known for their high specificity and affinity, aptamers were first selected from live cells by the cell-SELEX (systematic evolution of ligands by exponential enrichment) process. When next combined with the unique optical properties of gold nanoparticles (Au-NPs), ANSBs were prepared on a lateral flow device. Ramos cells were used as a model target cell to demonstrate proof of principle. Under optimal conditions, the ANSB was capable of detecting a minimum of 4000 Ramos cells without instrumentation (visual judgment) and 800 Ramos cells with a portable strip reader within 15 minutes. Importantly, ANSB has successfully detected Ramos cells in human blood, thus providing a rapid, sensitive and low-cost quantitative tool for the detection of circulating cancer cells. ANSB therefore shows great promise for in-field and point-of-care cancer diagnosis and therapy. PMID:19904989

Three temperature regimes in superconducting photon detectors: quantum, thermal and multiple phase-slips as generators of dark counts.

PubMed

Murphy, Andrew; Semenov, Alexander; Korneev, Alexander; Korneeva, Yulia; Gol'tsman, Gregory; Bezryadin, Alexey

2015-05-19

We perform measurements of the switching current distributions of three w ≈ 120 nm wide, 4 nm thick NbN superconducting strips which are used for single-photon detectors. These strips are much wider than the diameter of the vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We discover evidence of macroscopic quantum tunneling by observing the saturation of the standard deviation of the switching distributions at temperatures around 2 K. We analyze our results using the Kurkijärvi-Garg model and find that the escape temperature also saturates at low temperatures, confirming that at sufficiently low temperatures, macroscopic quantum tunneling is possible in quasi-2D strips and can contribute to dark counts observed in single photon detectors. At the highest temperatures the system enters a multiple phase-slip regime. In this range single phase-slips are unable to produce dark counts and the fluctuations in the switching current are reduced.

Strip-Bark Morphology and Radial Growth Trends in Ancient Pinus sibirica Trees From Central Mongolia

NASA Astrophysics Data System (ADS)

Leland, Caroline; Cook, Edward R.; Andreu-Hayles, Laia; Pederson, Neil; Hessl, Amy; Anchukaitis, Kevin J.; Byambasuren, Oyunsanaa; Nachin, Baatarbileg; Davi, Nicole; D'Arrigo, Rosanne; Griffin, Kevin; Bishop, Daniel A.; Rao, Mukund Palat

2018-03-01

Some of the oldest and most important trees used for dendroclimatic reconstructions develop strip-bark morphology, in which only a portion of the stem contains living tissue. Yet the ecophysiological factors initiating strip bark and the potential effect of cambial dieback on annual ring widths and tree-ring estimates of past climate remain poorly understood. Using a combination of field observations and tree-ring data, we investigate the causes and timing of cambial dieback events in Pinus sibirica strip-bark trees from central Mongolia and compare the radial growth rates and trends of strip-bark and whole-bark trees over the past 515 years. Results indicate that strip bark is more common on the southern aspect of trees, and dieback events were most prevalent in the 19th century, a cold and dry period. Further, strip-bark and whole-bark trees have differing centennial trends, with strip-bark trees exhibiting notably large increases in ring widths at the beginning of the 20th century. We find a steeper positive trend in the strip-bark chronology relative to the whole-bark chronology when standardizing with age-dependent splines. We hypothesize that localized warming on the southern side of stems due to solar irradiance results in physiological damage and dieback and leads to increasing tree-ring increment along the living portion of strip-bark trees. Because the impact of cambial dieback on ring widths likely varies depending on species and site, we suggest conducting a comparison of strip-bark and whole-bark ring widths before statistically treating ring-width data for climate reconstructions.

Comparisons of boll weevil (Coleoptera: Curculionidae) pheromone traps with and without kill strips.

PubMed

Suh, C P C; Armstrong, J S; Spurgeon, D W; Duke, S

2009-02-01

Boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), eradication programs typically equip pheromone traps with an insecticide-impregnated kill strip. These strips are intended to kill captured insects, thereby simplifying trap servicing and reducing the loss of weevils from predation and escape. However, the effectiveness of kill strips has not been extensively evaluated. We examined the influences of kill strips on weevil captures, trap servicing, and the incidences of weevil predation and trap obstruction (e.g., by spider webs). Evaluations were conducted weekly during three different production periods (pre- to early-, late-, and postseason) of cotton, Gossypium hirsutum L., to represent different environmental conditions and weevil population levels. Within each period, mean weekly captures of weevils in traps with and without kill strips were statistically similar. On average, traps with kill strips took 9 s longer to service than traps without kill strips, but statistical differences were only detected during the late-season period. Overall, the mean weekly proportion of traps with evidence of weevil predation or trap obstruction was significantly lower for traps with kill strips (0.25) than for traps without kill strips (0.37). However, this reduction in the frequency of weevil predation or trap obstruction was too small to produce a corresponding increase in the numbers of weevils captured. In light of these findings, the use of kill strips is likely unnecessary in eradication programs, but may be a consideration in situations when the numbers of deployed traps are reduced and chronic problems with weevil predation or trap obstruction exist.

Analytic description of the frictionally engaged in-plane bending process incremental swivel bending (ISB)

NASA Astrophysics Data System (ADS)

Frohn, Peter; Engel, Bernd; Groth, Sebastian

2018-05-01

Kinematic forming processes shape geometries by the process parameters to achieve a more universal process utilizations regarding geometric configurations. The kinematic forming process Incremental Swivel Bending (ISB) bends sheet metal strips or profiles in plane. The sequence for bending an arc increment is composed of the steps clamping, bending, force release and feed. The bending moment is frictionally engaged by two clamping units in a laterally adjustable bending pivot. A minimum clamping force hindering the material from slipping through the clamping units is a crucial criterion to achieve a well-defined incremental arc. Therefore, an analytic description of a singular bent increment is developed in this paper. The bending moment is calculated by the uniaxial stress distribution over the profiles' width depending on the bending pivot's position. By a Coulomb' based friction model, necessary clamping force is described in dependence of friction, offset, dimensions of the clamping tools and strip thickness as well as material parameters. Boundaries for the uniaxial stress calculation are given in dependence of friction, tools' dimensions and strip thickness. The results indicate that changing the bending pivot to an eccentric position significantly affects the process' bending moment and, hence, clamping force, which is given in dependence of yield stress and hardening exponent. FE simulations validate the model with satisfactory accordance.

Herbert Marcuse's Critical Theory of the Media.

ERIC Educational Resources Information Center

Daley, Patrick J.

As a member of the Frankfurt School of critical theory, Herbert Marcuse believed that industrial capitalism and the bureaucratization of society stripped humans of any claims to autonomy and undermined their critical expression with a functional language. However, Marcuse did no more than point an inchoate ideological finger at the production side…

Setback distance requirements for removal of swine slurry constituents in runoff

USDA-ARS?s Scientific Manuscript database

The establishment of vegetative filter strips at the bottom of a hillslope has been shown to substantially reduce nutrients and sediment in runoff. The use of setback distances on cropland areas could serve a similar function. However, there is little information available to help identify setback ...

PDES Application Protocol Suite for Composites (PAS-C). Functional Needs Report for the PAS-C Program

DTIC Science & Technology

1991-09-01

103 A2352344 Layup Cover Sheets/Inspect ............................. 103 A2352345 Perform Automated Tape Laying operations...A2352345 Perform Automated Tape Laying operations/Inspect The tape is layed in 3-12 inch strips along the surface of the bond mold. The NC program is

Using Comic Strips in Language Classes

ERIC Educational Resources Information Center

Csabay, Noémi

2006-01-01

The author believes that using comic strips in language-learning classes has three main benefits. First, comic strips motivate younger learners. Second, they provide a context and logically connected sentences to help language learning. Third, their visual information is helpful for comprehension. The author argues that comic strips can be used in…

76 FR 48122 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

... Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty Administrative Review... on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative... antidumping duty order on PET film from Brazil. See Polyethylene Terephthalate Film, Sheet, and Strip From...

75 FR 49900 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-16

... Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty Administrative Review... on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative... on PET film from Brazil. See Polyethylene Terephthalate Film, Sheet, and Strip From Brazil, the...

Water treatment capacity of forward osmosis systems utilizing power plant waste heat

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

Zhou, Xingshi; Gingerich, Daniel B.; Mauter, Meagan S.

Forward osmosis (FO) has the potential to improve the energy efficiency of membrane-based water treatment by leveraging waste heat from steam electric power generation as the primary driving force for separation. In this study, we develop a comprehensive FO process model, consisting of membrane separation, heat recovery, and draw solute regeneration (DSR) models. We quantitatively characterize three alternative processes for DSR: distillation, steam stripping, and air stripping. We then construct a mathematical model of the distillation process for DSR that incorporates hydrodynamics, mass and heat transport resistances, and reaction kinetics, and we integrate this into a model for the fullmore » FO process. Finally, we utilize this FO process model to derive a first-order approximation of the water production capacity given the rejected heat quantity and quality available at U.S. electric power facilities. We find that the upper bound of FO water treatment capacity using low-grade heat sources at electric power facilities exceeds process water treatment demand for boiler water make-up and flue gas desulfurization wastewater systems.« less

Water treatment capacity of forward osmosis systems utilizing power plant waste heat

DOE PAGES

Zhou, Xingshi; Gingerich, Daniel B.; Mauter, Meagan S.

2015-06-11

Forward osmosis (FO) has the potential to improve the energy efficiency of membrane-based water treatment by leveraging waste heat from steam electric power generation as the primary driving force for separation. In this study, we develop a comprehensive FO process model, consisting of membrane separation, heat recovery, and draw solute regeneration (DSR) models. We quantitatively characterize three alternative processes for DSR: distillation, steam stripping, and air stripping. We then construct a mathematical model of the distillation process for DSR that incorporates hydrodynamics, mass and heat transport resistances, and reaction kinetics, and we integrate this into a model for the fullmore » FO process. Finally, we utilize this FO process model to derive a first-order approximation of the water production capacity given the rejected heat quantity and quality available at U.S. electric power facilities. We find that the upper bound of FO water treatment capacity using low-grade heat sources at electric power facilities exceeds process water treatment demand for boiler water make-up and flue gas desulfurization wastewater systems.« less

A Theoretical Model for Thin Film Ferroelectric Coupled Microstripline Phase Shifters

NASA Technical Reports Server (NTRS)

Romanofsky, R. R.; Quereshi, A. H.

2000-01-01

Novel microwave phase shifters consisting of coupled microstriplines on thin ferroelectric films have been demonstrated recently. A theoretical model useful for predicting the propagation characteristics (insertion phase shift, dielectric loss, impedance, and bandwidth) is presented here. The model is based on a variational solution for line capacitance and coupled strip transmission line theory.

The Effect of Floral Resources on Parasitoid and Host Longevity: Prospects for Conservation Biological Control in Strawberries

PubMed Central

Sigsgaard, Lene; Betzer, Cathrine; Naulin, Cyril; Eilenberg, Jørgen; Enkegaard, Annie; Kristensen, Kristian

2013-01-01

The strawberry tortricid, Acleris comariana Lienig and Zeller (Lepidoptera: Tortricidae) is an important pest in Danish strawberry production. Its most common parasitoid is Copidosoma aretas (Walker) (Hymenoptera: Chalcidoidea: Encyrtidae). To identify selective flowering plants that could be used to increase functional biodiversity, the longevity of C. aretas and its host A. comariana was assessed on 5 flowering species: buckwheat, Fagopyrum esculentum Moench (Caryophyllales: Polygonaceae); borage, Borago officinalis L. (Boraginaceae); strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae); phacelia, Phacelia tanacetifolia Bentham (Boraginaceae); and dill, Anethum graveolens L. (Apiales: Apiaceae). Dill was only tested with C. aretas. Sucrose and pollen served as positive controls, and pure water as a negative control. In a subsequent field experiment, A. comariana larval density was assessed at 1, 6, and 11 m distances from buckwheat flower strips in 3 fields. The proportion of field-collected larvae that were parasitized by C. aretas or fungi was assessed. Among the tested floral diets, buckwheat was superior for C. aretas, increasing its longevity by 1.4 times compared to water. Although buckwheat also increased longevity of A. comariana, its longevity and survival on buckwheat, borage, and strawberry was not significantly different, so buckwheat was chosen for field experiments. A. comariana densities in the 3 fields with sown buckwheat flower strips were 0.5, 4.0, and 8.3 larvae per m per row of strawberry respectively. Of the collected larvae, a total of 1%, 39%, and 65% were parasitized by C. aretas, respectively. The density of A. comariana and the proportion parasitized by C. aretas were highly significantly correlated. Distance from floral strips had no significant effect on either A. comariana larval density or on the proportion of individuals parasitized by C. aretas. Few other parasitoids emerged from collected larvae, and no larvae were infected by entomopathogenic fungi. Still, total A. comariana mortality was significantly affected by distance to flower strips, with the highest mortality near the flower strips. As no effect of buckwheat flower strips on C. aretas parasitism was found, the positive effect they had on A. comariana control stems from unknown mortality factors. As literature indicates that buckwheat for flower strips can augment a more complex suite of natural enemies, one such mortality factor could be a non-consumptive predator and/or parasitoid effect, but this requires further study. If confirmed, buckwheat may be utilized together with a selective food plant, once identified. PMID:24738921

APEX simulation: environmental benefits of agroforestry and grass buffers on corn-soybean watersheds

USDA-ARS?s Scientific Manuscript database

The Agricultural Policy Environmental Extender (APEX) model has the ability to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. The objectives of this study were to calibrate and validate the APEX model for three adjacent watersheds and...

Studies on the stripping of cerium from the loaded tbp-kerosene solution

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

Rizk, S.E.; Abdel Rahman, N.; Daoud, J.A.

2008-07-01

The reductive stripping of Ce(IV) from the loaded organic phase (30% TBP in kerosene) was investigated, using two stripping agents, EDTA and H{sub 2}O{sub 2}, in nitric acid. The results are compared to determine the optimum conditions for the reduction of Ce(IV) in the organic phase to Ce(III) in the aqueous phase. For each of the two stripping agents, the effect of different parameters affecting the reduction process was investigated: stripping-agent concentration, nitric acid concentration, phase ratio, shaking time, and temperature. The results are compared and discussed in terms of the conditions required for maximum reductive stripping of Ce(IV). (authors)

Estimating effectiveness of crop management for reduction of soil erosion and runoff

NASA Astrophysics Data System (ADS)

Hlavcova, K.; Studvova, Z.; Kohnova, S.; Szolgay, J.

2017-10-01

The paper focuses on erosion processes in the Svacenický Creek catchment which is a small sub-catchment of the Myjava River basin. To simulate soil loss and sediment transport the USLE/SDR and WaTEM/SEDEM models were applied. The models were validated by comparing the simulated results with the actual bathymetry of a polder at the catchment outlet. Methods of crop management based on rotation and strip cropping were applied for the reduction of soil loss and sediment transport. The comparison shows that the greatest intensities of soil loss were achieved by the bare soil without vegetation and from the planting of maize for corn. The lowest values were achieved from the planting of winter wheat. At the end the effectiveness of row crops and strip cropping for decreasing design floods from the catchment was estimated.

The turn of the screw: an exercise in protein secondary structure.

PubMed

Pikaart, Michael

2011-01-01

An exercise using simple paper strips to illustrate protein helical and sheet secondary structures is presented. Drawing on the rich historical context of the use of physical models in protein biochemistry by early practitioners, in particular Linus Pauling, the purpose of this activity is to cultivate in students a hands-on, intuitive sense of protein secondary structure and to complement the common computer-based structural portrayals often used in teaching biochemistry. As students fold these paper strips into model secondary structures, they will better grasp how intramolecular hydrogen bonds form in the folding of a polypeptide into secondary structure, and how these hydrogen bonds direct the overall shape of helical and sheet structures, including the handedness of the α-helix and the difference between right- and the left-handed twist. Copyright © 2010 Wiley Periodicals, Inc.

[Theory of mind in Asperger syndrome].

PubMed

Duverger, H; Da Fonseca, D; Bailly, D; Deruelle, C

2007-09-01

Theory of mind deficit can be used to explain social and communication impairments that define the autism spectrum disorder. Theory of mind is the ability to attribute mental states to self and others in order to understand and predict behavior. It involves the distinction between the real world and mental representations of the world. Several studies established that high functioning autistic individuals and individuals with Asperger syndrome (ASP) tend to be as proficient as controls in understanding first order false belief tasks. In contrast, they still lag behind their typical peers in understanding second order false belief tasks or more advanced tasks of theory of mind (e.g., Baron-Cohen, 1993). Most of these studies focus on the adult population and it seems particularly interesting to investigate whether children with ASP would present the same pattern of strengths and deficits as adults. In our research, children with ASP were tested in an advanced task of theory of mind based on a visual presentation of comic strips and in a more traditional assessment of false belief understanding: the Smarties test. Two experimental groups participated in this study: a group of 16 high functioning children and adolescents with autism or with Asperger syndrome (ASP) and a group of 16 typically developing children matched on gender and age (CONT). The task was designed to assess the ability of children with ASP to infer the mental state of others. Stimuli were 26 different comic strips depicting a short story. Each comic strip was composed of three pictures and was shown on the upper half of the screen. Then three pictures numbered 1 to 3 showing possible outcomes of the scenario were superimposed on the bottom half of the screen. Only one of these three pictures represented a plausible conclusion to the scenario. This experiment contained two conditions: A Character intention (CI) condition and a Physical causality (PC) condition. The comic strips in the CI condition involved one character whose intentions had to be inferred by the subject in order to choose the correct picture. Comic strips in PC condition only required to understand physical causalities. Subjects were asked to watch the comic strip attentively and then they were required to make a choice between the three story endings by pressing the corresponding keyboard button. Both answers and response times were recorded. Additionally, all participants were enrolled in the classical false belief (Smarties) task. Comic strips: An ANOVA [2 groups (CONT/ASP) x 2 conditions (CI/PC)] was performed on the number of correct responses. Neither the Group nor the Condition factor was significant (p>0.05). In contrast, the interaction Group x Condition reached significance level [F(1-30)=4.3, p<0.05)]. Further analysis revealed that performance of the ASP group was significantly higher in the CP (M=10.8, SD=2.5) than in the CI (M=9.8, SD=2) condition [t (1-14)=2.9, p<0.001)], whereas there was no condition difference in the control group (p>0.05). False belief: all ASP participants succeeded in the task. Our data clearly demonstrated that children and adolescents with Asperger syndrome or high functioning autism exhibited an impairment in understanding the intention of others. In the comic strip task, children with ASP have more difficulties in the character's intention condition than in the physical causality condition. This impairment is not imputable to a deficit in taking into account the context (Weack Central Coherence theory) since they performed as well as controls in the physical causality condition which also required the processing of the whole scene. In contrast, all children with ASP succeeded at the false belief task. These contradictory findings suggest that, although testing theory of mind, the two tasks do not tap similar mechanisms. It is possible that the use of verbal material in the false belief task improved performance of the ASP children who are known to present particular strengths in this domain. Another possible explanation that needs further testing would be that the level of complexity differs between the two tasks.