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Sample records for deg fiber orientation

  1. Oriented Fiber Filter Media

    Directory of Open Access Journals (Sweden)

    R. Bharadwaj

    2008-06-01

    Full Text Available Coalescing filters are widely used throughout industry and improved performance will reduce droplet emissions and operating costs. Experimental observations show orientation of micro fibers in filter media effect the permeability and the separation efficiency of the filter media. In this work two methods are used to align the fibers to alter the filter structure. The results show that axially aligned fiber media improve quality factor on the order of 20% and cutting media on an angle from a thick layered media can improve performance by about 40%. The results also show the improved performance is not monotonically correlated to the average fiber angle of the medium.

  2. Neuroanatomic Fiber Orientation Maps (FOMs)

    DEFF Research Database (Denmark)

    Axer, Hubertus; Jantzen, Jan; Grässel, David;

    2002-01-01

    A new neuroanatomic method is described which allows to map the orientation of central nervous fibers in gross histological sections. Polarised light is used to calculate the angle of inclination and direction of the fibers in each pixel. Serial fiber orientation maps (FOMs) can be aligned and 3D...... reconstructed. This volume allows to identify and segment the major fiber tracts. The feasible goal is a human central nervous fiber atlas....

  3. Neuroanatomic Fiber Orientation Maps (FOMs)

    DEFF Research Database (Denmark)

    Axer, Hubertus; Jantzen, Jan; Grässel, David

    2002-01-01

    A new neuroanatomic method is described which allows to map the orientation of central nervous fibers in gross histological sections. Polarised light is used to calculate the angle of inclination and direction of the fibers in each pixel. Serial fiber orientation maps (FOMs) can be aligned and 3D...

  4. Quantification of fiber orientation in the canine atrial pacemaker complex using optical coherence tomography

    Science.gov (United States)

    Ambrosi, Christina M.; Fedorov, Vadim V.; Schuessler, Richard B.; Rollins, Andrew M.

    2012-01-01

    Abstract The atrial pacemaker complex is responsible for the initiation and early propagation of cardiac impulses. Optical coherence tomography (OCT), a nondestructive imaging modality with spatial resolutions of ∼1 to 15 μm, can be used to identify unique fiber orientation patterns in this region of the heart. Functionally characterized canine sinoatrial nodes (SAN) (n=7) were imaged using OCT up to ∼1  mm below the endocardial tissue surface. OCT images were directly compared to their corresponding histological sections. Fiber orientation patterns unique to the crista terminalis (CT), SAN, and surrounding atrial myocardium were identified with dominant average fiber angles of 89±12  deg, 110±16  deg, and 95±35  deg, respectively. Both the CT and surrounding atrial myocardium displayed predominantly unidirectionally based fiber orientation patterns within each specimen, whereas the SAN displayed an increased amount of fiber disarray manifested quantitatively as a significantly greater standard deviation in fiber angle distribution within specimens [33±7  deg versus 23±5  deg, atrium (p=0.02); 18±3  deg, CT (p=0.0003)]. We also identified unique, local patterns of fiber orientation specific to the functionally characterized block zone. We demonstrate the ability of OCT in detecting components of the atrial pacemaker complex which are intimately involved in both normal and abnormal cardiac conduction. PMID:22894470

  5. FIBER ORIENTATION IN INJECTION MOLDED LONG CARBON FIBER THERMOPLASTIC COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin; Nguyen, Ba Nghiep; Mathur, Raj N.; Sharma, Bhisham; Sangid, Michael D.; Costa, Franco; Jin, Xiaoshi; Tucker III, Charles L.; Fifield, Leonard S.

    2015-03-23

    A set of edge-gated and center-gated plaques were injection molded with long carbon fiber-reinforced thermoplastic composites, and the fiber orientation was measured at different locations of the plaques. Autodesk Simulation Moldflow Insight (ASMI) software was used to simulate the injection molding of these plaques and to predict the fiber orientation, using the anisotropic rotary diffusion and the reduced strain closure models. The phenomenological parameters of the orientation models were carefully identified by fitting to the measured orientation data. The fiber orientation predictions show very good agreement with the experimental data.

  6. Automatic Fiber Orientation Detection for Sewed Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Automatic production and precise positioning of carbon fiber reinforced plastics (FRP) require precise detection of the fiber orientations. This paper presents an automatic method for detecting fiber orientations of sewed carbon fibers in the production of FRP. Detection was achieved by appropriate use of regional filling, edge detection operators, autocorrelation methods, and the Hough transformation. Regional filling was used to reduce the influence of the sewed regions, autocorrelation was used to clarify the fiber directions, edge detection operators were used to extract the edge features for the fiber orientations, and the Hough transformation was used to calculate the angles. Results for two kinds of carbon fiber materials show that the method is relatively quick and precise for detecting carbon fiber orientations.

  7. Extruded electroactive fibers: preferred crystallographic orientation

    Science.gov (United States)

    Strock, Harold B.; Pascucci, Marina R.; Bystricky, Pavel

    2001-07-01

    Electroactive fibers of preferred macro crystalline orientation and ultimately single crystal structure are goals of the research discussed in this paper. Four compositions are under evaluation; lead magnesium niobate- lead titanate solid solution, PMN-31PT, an incongruently melting near-morphotropic phase boundary piezoelectric composition; PMN-10PT, an electrostrictor composition; and two lead free compositions in the sodium bismuth titanate- barium titanate solid solution, NbiT-BaT, family, both congruently melting, one electrostrictor and one piezoelectric. The efficacy of seed crystals in stimulating oriented crystal growth is being evaluated in the lead-based PMN-31PT system. Sub-micron reactive precursor powders of high chemical potential are being evaluated as matrix material. Direct fiber and ribbon extrusion have been shown to orient high chemical potential are being evaluated as matrix material. Direct fiber and ribbon extrusion have been shown to orient high chemical potential are being evaluated as matrix material. Direct fiber and ribbon extrusion have been shown to orient prismatic, needle and platelet shaped seed crystals. Extrusion orifice, seed and initial matrix particle size have not influenced the degree of seed orientation within the tested bounds of our experimental parameters. Non-equilibrium sintering conditions near the melting points of all four compositions noted above will be used to generate exaggerated grain growth under seeded and self-seeding conditions. In the PMN-31PT system, an as yet uncharacterized melt phase appears to stimulate rapid crystal growth, the orientation of which shall be determined by x-ray back reflection Laue methods. Analyses of fiber composition and grain orientation are ongoing. Results to-date will be reported. Analyses of fiber quality and performance, measured using single fiber P-E loop testing, are presented. Loops of sufficient quality to warrant fiber evaluation in active fiber composite packs have

  8. Oriented collagen fibers direct tumor cell intravasation

    KAUST Repository

    Han, Weijing

    2016-09-24

    In this work, we constructed a Collagen I-Matrigel composite extracellular matrix (ECM). The composite ECM was used to determine the influence of the local collagen fiber orientation on the collective intravasation ability of tumor cells. We found that the local fiber alignment enhanced cell-ECM interactions. Specifically, metastatic MDA-MB-231 breast cancer cells followed the local fiber alignment direction during the intravasation into rigid Matrigel (∼10 mg/mL protein concentration).

  9. Failure Plane Orientations for Fiber Composites

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, R.M.; DeTeresa, S.J.

    2002-07-12

    Using a recently developed failure theory for transversely isotropic fiber composites, it is shown how the orientation of the failure surface can be determined for transverse tension and compression. Experimental data on failure surface orientations have been obtained for four carbon fiber composite systems based on both thermoplastic and thermosetting matrix materials. Average compression failure planes for the different composite materials were measured to range from 31{sup o} to 38{sup o} from the load axis. Reasonable agreement was obtained between these measured angles and those predicted from application of the new failure theory.

  10. Z-direction fiber orientation in paperboard

    Science.gov (United States)

    John M. Considine; David W. Vahey; Roland Gleisner; Alan Rudie; Sabine Rolland du Roscoat; Jean-Francis Bloch

    2010-01-01

    This work evaluated the use of conventional tests to show beneficial attributes of z-direction fiber orientation (ZDFO) for structural paperboards. A survey of commercial linerboards indicated the presence of ZDFO in one material that had higher Taber stiffness, out-of-plane shear strength, directional dependence of Scott internal bond strength and directional...

  11. Computational Representation of White Matter Fiber Orientations

    Directory of Open Access Journals (Sweden)

    Adelino R. Ferreira da Silva

    2013-01-01

    Full Text Available We present a new methodology based on directional data clustering to represent white matter fiber orientations in magnetic resonance analyses for high angular resolution diffusion imaging. A probabilistic methodology is proposed for estimating intravoxel principal fiber directions, based on clustering directional data arising from orientation distribution function (ODF profiles. ODF reconstructions are used to estimate intravoxel fiber directions using mixtures of von Mises-Fisher distributions. The method focuses on clustering data on the unit sphere, where complexity arises from representing ODF profiles as directional data. The proposed method is validated on synthetic simulations, as well as on a real data experiment. Based on experiments, we show that by clustering profile data using mixtures of von Mises-Fisher distributions it is possible to estimate multiple fiber configurations in a more robust manner than currently used approaches, without recourse to regularization or sharpening procedures. The method holds promise to support robust tractographic methodologies and to build realistic models of white matter tracts in the human brain.

  12. Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation

    OpenAIRE

    Jeong-Il Choi; Bang Yeon Lee

    2015-01-01

    The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber’s suitability as a reinforcing fiber. Single fiber pullout tests were performed and then th...

  13. FIBER ORIENTATION DISTRIBUTIONS IN SLIT CHANNEL FLOWS WITH ABRUPT EXPANSION FOR FIBER SUSPENSIONS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The lattice Boltzmann method was used to investigate numerically the fiber orientation distributions in slit channel flows with abrupt expansion for fiber suspensions even in the concentrated regime. The channels have a thin slit geometry with 1:4 and 1:3 expansions. Both the interactions between fibers and that between fibers and channel walls were taken into consideration. Some of numerical results are qualitatively in agreement with the experiment data. It is found that most of fibers are aligned in the flow direction in all the suspensions in the entrance region of the expansion. Fiber orientation distributions, having different patterns in different regions of the flow, depend on the expansion ratio of the channel. The mechanical fiber-fiber interaction largely affects the fiber orientation in the downstream of the expansion and in the salient corner for the cases of concentrated suspensions. The hydrodynamic interaction plays an important role on the fiber orientation in the dilute suspension.

  14. Ten deg off-axis tensile test for intralaminar shear characterization of fiber composites

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1976-01-01

    A combined theoretical and experimental investigation was conducted to assess the suitability of the 10 deg off-axis tensile test specimen for the intralaminar shear characterization of unidirectional composites. Composite mechanics, a combined-stress failure criterion, and a finite element analysis were used to determine theoretically the stress-strain variation across the specimen width and the relative stress and strain magnitudes at the 10 deg plane. Strain gages were used to measure the strain variation across the specimen width at specimen midlength and near the end tabs. Specimens from Mod-I/epoxy, T-300/epoxy, and S-glass/epoxy were used in the experimental program. It was found that the 10 deg off-axis tensile test specimen is suitable for intralaminar shear characterization and it is recommended that it should be considered as a possible standard test specimen for such a characterization.

  15. Direct fiber strengthening in three dimensional random-oriented short-fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Y.T.; Blumenthal, W.R.

    1995-05-01

    A theory for direct fiber strengthening in random-oriented short-fiber composites is developed. It adopts a maximum load composite failure criterion and takes into account the fiber orientation effect on the probability of a fiber being intercepted by a specimen cross-section. The strain and load of short fibers with different inclination angles with respect to the loading direction were first calculated, and their contribution in carrying load toward the composite load direction was integrated to give the total load. The fibers with smaller inclination angles bear greater stress and break first. This load is then transferred to fibers with larger inclination angles. Direct fiber strengthening component of the composite strength was calculated from the maximum total load these short fibers can carry. The present theory predicts a much greater direct short-fiber strengthening than does previous theories, and provides useful information for composite design and strength assessment.

  16. Numerical approach of the injection molding process of fiber-reinforced composite with considering fiber orientation

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Thi, T. B., E-mail: thanhbinh.skku@gmail.com, E-mail: yokoyama@kit.ac.jp; Yokoyama, A., E-mail: thanhbinh.skku@gmail.com, E-mail: yokoyama@kit.ac.jp [Department of Advanced Fibro-Science, Kyoto Institute of Technology (Japan); Ota, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Kodama, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Yamashita, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Isogai, Y., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Furuichi, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Nonomura, C., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp [Toyobo Co., LTD. Research Center (Japan)

    2014-05-15

    One of the most important challenges in the injection molding process of the short-glass fiber/thermoplastic composite parts is being able to predict the fiber orientation, since it controls the mechanical and the physical properties of the final parts. Folgar and Tucker included into the Jeffery equation a diffusive type of term, which introduces a phenomenological coefficient for modeling the randomizing effect of the mechanical interactions between the fibers, to predict the fiber orientation in concentrated suspensions. Their experiments indicated that this coefficient depends on the fiber volume fraction and aspect ratio. However, a definition of the fiber interaction coefficient, which is very necessary in the fiber orientation simulations, hasn't still been proven yet. Consequently, this study proposed a developed fiber interaction model that has been introduced a fiber dynamics simulation in order to obtain a global fiber interaction coefficient. This supposed that the coefficient is a sum function of the fiber concentration, aspect ratio, and angular velocity. The proposed model was incorporated into a computer aided engineering simulation package C-Mold. Short-glass fiber/polyamide-6 composites were produced in the injection molding with the fiber weight concentration of 30 wt.%, 50 wt.%, and 70 wt.%. The physical properties of these composites were examined, and their fiber orientation distributions were measured by micro-computed-tomography equipment μ-CT. The simulation results showed a good agreement with experiment results.

  17. Comparison of fiber orientation and tensile-stiffness orientation measurements in paper

    Science.gov (United States)

    David W. Vahey; John M. Considine; Andy Kahra; Mark Scotch

    2008-01-01

    We have had the opportunity to subject cross-machine paper strips from two mills to both ultrasound and optical "fiber-orientation" tests to examine the relationships between the results. Both determine an orientation angle, in degrees. Both measure sheet anisotropy as an MD/CD orientation ratio. The optical test has no counterpart to the ultrasonic...

  18. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    Directory of Open Access Journals (Sweden)

    Heidi Peltola

    2011-01-01

    Full Text Available Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens. The effect of processing, melt viscosity and fiber type on the fiber length was investigated. The lengths of fully processed fibers were determined by dissolving the matrix and measuring the length of the remaining fibers by microscope analysis. A clear reductive effect of the processing on the fiber length was noticed. A reduction of fiber length along the increasing fiber content and the decreasing plasticizer content was also detected. This reduction originated from the increasing shear forces during compounding, which again depended on the increased viscosity of the material. Hemp fibers were shown to remain longer and fibrillate more than flax fibers, leading to higher aspect ratio. Thus, the reinforcement efficiency of hemp fibers by the processing was improved, in contrast with flax fibers. In addition, the analysis of fiber dispersion and orientation showed a good dispersion of fibers in the matrix, and a predominant orientation of the fibers in the melt flow direction.

  19. FIBER ORIENTATION DISTRIBUTION OF PAPER SURFACE CALCULATED BY IMAGE ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    Toshiharu Enomae; Yoon-Hee Han; Akira Isogai

    2004-01-01

    Anisotropy of paper is an important parameter of paper structure. Image analysis technique was improved for accurate fiber orientation in paper surfaces. Image analysis using Fast Fourier Transform was demonstrated to be an effective means to determine fiber orientation angle and its intensity. Binarization process of micrograph images of paper surface and precise calculation for average Fourier coefficients as an angular distribution by interpolation developed were found to improve the accuracy. This analysis method was applied to digital optical micrographs and scanning electron micrographs of paper. A laboratory handsheet showed a large deviation in the average value of fiber orientation angle, but some kinds of machine-made paper showed about 90 degrees in the orientation angle with very small deviations as expected. Korea and Japanese paper made in the traditional ways showed its own characteristic depending on its hand making processes.

  20. Electrospinning of oriented and nonoriented ultrafine fibers of biopolymers

    Science.gov (United States)

    Vu, David

    2005-07-01

    Chitosan has long been known as a biocompatible and biodegradable material suitable for tissue engineering applications. Unfortunately, conventional chitosan solutions cannot be used for electrospinning due to their high conductivity, viscosity and surface tension. We have developed a method to produce clear chitosan solutions with conductivities, surface tension and viscosities that facilitate their processing into micron and submicron fibers via electrospinning. Acetic acid, carbon dioxide and organic solvents are key ingredients in preparing the chitosan solutions. Oriented and non oriented chitosan fibers were produced with the ultimate goal of designing a suitable tissue engineering scaffold. Circularly oriented, continuous, and aligned nanofibers were produced via this technique in the form of a thin membrane or fibrous "mat". Chitosan fiber diameters ranged from 5 micrometers down to 100 nanometers. The structure and mechanical properties of oriented and randomly aligned chitosan fiber deposits could potentially be exploited for cartilage tissue engineering. Ultrafine fibers of starch acetate (SA) also were prepared by the electrospinning process. In this study, solvent mixtures based on DMF, DMSO, pyrindine, acetic acid, acetone, THF, DMC, chloroform were used. A two-solvent formulation was used to study the effect of viscosity, surface tension, and conductivity to the fiber diameter. Also, water and ethanol were used to decrease the boiling point of the solvent, and to make bundled fibers. Several techniques such as scanning electron microscopy, conductmetry, viscometry, and tensiometry were used in this study. The results showed that the combined effects of viscosity, surface tension, and conductivity are of great importance in controlling the diameter of the fibers. We were able to produce SA fibers that was less than 40 nm in diameter. The dependence of fiber diameter on flow-rate, electric field and solvents also was investigated. A rotating disk and a

  1. Orientation distribution of fibers and rheological property in fiber suspensions flowing in a turbulent boundary layer

    Institute of Scientific and Technical Information of China (English)

    Jian Zhong Lin; Ke Sun; Weifeng Zhang

    2008-01-01

    A model relating the translational and rotational transport of orientation distribution function (ODF) of fibers to the gradient of mean ODF and the dispersion coefficients is proposed to derive the mean equation for the ODE Then the ODF of fibers is predicted by numerically solving the mean equation for the ODF together with the equations of turbulent boundary layer flow. Finally the shear stress and first normal stress difference of fiber suspensions are obtained. The results, some of which agree with the available relevant experimental data, show that the most fibers tend to orient to the flow direction. The fiber aspect ratio and Reynolds number have significant and negligible effects on the orientation distribution of fibers, respectively. The additional normal stress due to the presence of fibers is anisotropic. The shear stress of fiber suspension is larger than that of Newtonian solvent, and the first normal stress difference is much less than the shear stress. Both the additional shear stress and the first normal stress difference increase with increasing the fiber concentration and decreasing fiber aspect ratio.

  2. Influence of the Initial Fiber Orientation on the Weld Strength in Welding of Glass Fiber Reinforced Thermoplastics

    Directory of Open Access Journals (Sweden)

    Isabel Fiebig

    2016-01-01

    Full Text Available The welding factors are significantly lower in welding of fiber reinforced thermoplastics than in welding of unreinforced thermoplastics due to the fiber orientation in the weld. This paper presents results from investigations on the influence of the initial fiber orientation on the weld strength in hot plate and vibration welding for glass fiber reinforced polypropylene and polyamide 6. Injection molded specimens are compared to specimens with main initial fiber orientation being longitudinal and transverse to the joining direction. The results of CT analysis of the fiber orientation in the weld show the opportunity to achieve a higher weld strength by using specimens with fibers being initially oriented longitudinally to the joining direction. The influence of the initial fiber orientation in the parts to be welded on the weld strength in hot plate welding is more distinct than in vibration welding.

  3. Melting of highly oriented fiber DNA subjected to osmotic pressure.

    Science.gov (United States)

    Wildes, Andrew; Khadeeva, Liya; Trewby, William; Valle-Orero, Jessica; Studer, Andrew; Garden, Jean-Luc; Peyrard, Michel

    2015-03-26

    A pilot study of the possibility to investigate temperature-dependent neutron scattering from fiber-DNA in solution is presented. The study aims to establish the feasibility of experiments to probe the influence of spatial confinement on the structural correlation and the formation of denatured bubbles in DNA during the melting transition. Calorimetry and neutron scattering experiments on fiber samples immersed in solutions of poly(ethylene glycol) (PEG) prove that the melting transition occurs in these samples, that the transition is reversible to some degree, and that the transition is broader in temperature than for humidified fiber samples. The PEG solutions apply an osmotic pressure that maintains the fiber orientation, establishing the feasibility of future scattering experiments to study the melting transition in these samples.

  4. Numerical prediction of fiber orientation in injection-molded short-fiber/thermoplastic composite parts with experimental validation

    Science.gov (United States)

    Thi, Thanh Binh Nguyen; Morioka, Mizuki; Yokoyama, Atsushi; Hamanaka, Senji; Yamashita, Katsuhisa; Nonomura, Chisato

    2015-05-01

    Numerical prediction of the fiber orientation in the short-glass fiber (GF) reinforced polyamide 6 (PA6) composites with the fiber weight concentration of 30%, 50%, and 70% manufactured by the injection molding process is presented. And the fiber orientation was also directly observed and measured through X-ray computed tomography. During the injection molding process of the short-fiber/thermoplastic composite, the fiber orientation is produced by the flow states and the fiber-fiber interaction. Folgar and Tucker equation is the well known for modeling the fiber orientation in a concentrated suspension. They included into Jeffrey's equation a diffusive type of term by introducing a phenomenological coefficient to account for the fiber-fiber interaction. Our developed model for the fiber-fiber interaction was proposed by modifying the rotary diffusion term of the Folgar-Tucker equation. This model was presented in a conference paper of the 29th International Conference of the Polymer Processing Society published by AIP conference proceeding. For modeling fiber interaction, the fiber dynamic simulation was introduced in order to obtain a global fiber interaction coefficient, which is sum function of the fiber concentration, aspect ratio, and angular velocity. The fiber orientation is predicted by using the proposed fiber interaction model incorporated into a computer aided engineering simulation package C-Mold. An experimental program has been carried out in which the fiber orientation distribution has been measured in 100 x 100 x 2 mm injection-molded plate and 100 x 80 x 2 mm injection-molded weld by analyzed with a high resolution 3D X-ray computed tomography system XVA-160α, and calculated by X-ray computed tomography imaging. The numerical prediction shows a good agreement with experimental validation. And the complex fiber orientation in the injection-molded weld was investigated.

  5. Numerical prediction of fiber orientation in injection-molded short-fiber/thermoplastic composite parts with experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Thi, Thanh Binh Nguyen; Morioka, Mizuki; Yokoyama, Atsushi [Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Hamanaka, Senji; Yamashita, Katsuhisa; Nonomura, Chisato [Research Center, Toyobo Co., LTD, 2-1-1 Katata, Otsu, Shiga 520-0292 (Japan)

    2015-05-22

    Numerical prediction of the fiber orientation in the short-glass fiber (GF) reinforced polyamide 6 (PA6) composites with the fiber weight concentration of 30%, 50%, and 70% manufactured by the injection molding process is presented. And the fiber orientation was also directly observed and measured through X-ray computed tomography. During the injection molding process of the short-fiber/thermoplastic composite, the fiber orientation is produced by the flow states and the fiber-fiber interaction. Folgar and Tucker equation is the well known for modeling the fiber orientation in a concentrated suspension. They included into Jeffrey’s equation a diffusive type of term by introducing a phenomenological coefficient to account for the fiber-fiber interaction. Our developed model for the fiber-fiber interaction was proposed by modifying the rotary diffusion term of the Folgar-Tucker equation. This model was presented in a conference paper of the 29{sup th} International Conference of the Polymer Processing Society published by AIP conference proceeding. For modeling fiber interaction, the fiber dynamic simulation was introduced in order to obtain a global fiber interaction coefficient, which is sum function of the fiber concentration, aspect ratio, and angular velocity. The fiber orientation is predicted by using the proposed fiber interaction model incorporated into a computer aided engineering simulation package C-Mold. An experimental program has been carried out in which the fiber orientation distribution has been measured in 100 x 100 x 2 mm injection-molded plate and 100 x 80 x 2 mm injection-molded weld by analyzed with a high resolution 3D X-ray computed tomography system XVA-160α, and calculated by X-ray computed tomography imaging. The numerical prediction shows a good agreement with experimental validation. And the complex fiber orientation in the injection-molded weld was investigated.

  6. On the effect of the fiber orientation on the flexural stiffness of injection molded short fiber reinforced polycarbonate plates

    NARCIS (Netherlands)

    Neves, N.M.; Isdell, G.; Pouzada, A.S.; Powell, P.C.

    1998-01-01

    The through-thickness fiber orientation distribution of injection molded polycarbonate plates was experimentally determined by light reflection microscopy and manual digitization of polished cross sections. Fiber length distribution was determined by pyrolysis tests followed by image analysis. A sta

  7. Orientation-dependent fiber-optic accelerometer based on grating inscription over fiber cladding.

    Science.gov (United States)

    Rong, Qiangzhou; Qiao, Xueguang; Guo, Tuan; Bao, Weijia; Su, Dan; Yang, Hangzhou

    2014-12-01

    An orientation-sensitive fiber-optic accelerometer based on grating inscription over fiber cladding has been demonstrated. The sensor probe comprises a compact structure in which a short section of thin-core fiber (TCF) stub containing a "cladding" fiber Bragg grating (FBG) is spliced to another single-mode fiber (SMF) without any lateral offset. A femtosecond laser side-illumination technique was utilized to ensure that the grating inscription remains close to the core-cladding interface of the TCF. The core mode and the cladding mode of the TCF are coupled at the core-mismatch junction, and two well-defined resonances in reflection appear from the downstream FBG, in which the cladding resonance exhibits a strong polarization and bending dependence due to the asymmetrical distribution of the cladding FBG along the fiber cross section. Strong orientation dependence of the vibration (acceleration) measurement has been achieved by power detection of the cladding resonance. Meanwhile, the unwanted power fluctuations and temperature perturbations can be referenced out by monitoring the fundamental core resonance.

  8. Visualization of nerve fiber orientation in gross histological sections of the human brain.

    Science.gov (United States)

    Axer, H; Berks, G; Keyserlingk, D G

    2000-12-01

    Diffusion weighted magnetic resonance imaging (DWMRI) allows visualization of the orientation of the nervous fibers in the living brain. For comparison, a method was developed to examine the orientation of fibers in histological sections of the human brain. Serial sections through the entire human brain were analyzed regarding fiber orientation using polarized light. Direction of fibers in the cutting plane was obtained by measuring the azimuth with the lowest intensity value at each point, and inclination of fibers in the section was evaluated using fuzzy logic approximations. Direction and inclination of fibers revealing their three-dimensional orientation were visualized by colored arrows mapped into the images. Using this procedure, various fiber tracts were identified (pyramidal tract, radiatio optica, radiatio acustica, arcuate fascicle, and 11 more). Intermingled fibers could be separated from each other. The orientation of the fiber tracts derived from polarized light microscopy was validated by confocal laser scanning microscopy in a defined volume of the internal capsule, where the fiber orientation was studied in four human brains. The polarization method visualizes the high degree of intermingled fiber bundles in the brain, so that distinct fiber pathways cannot be understood as solid, compact tracts: Neighbouring bundles of fibers can belong to different systems of fibers distinguishable by their orientation.

  9. Orientation of Carbon Fibers in Copper matrix Produced by Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Irfan Shirazi M.

    2014-07-01

    Full Text Available Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection molding (PIM process has some intrinsic fiber alignment associated with it. During PIM process fibers in skin region of moldings are aligned as these regions experience higher shear flow caused by the mold walls. Fibers in the core region remain randomly aligned as these regions are far from mold walls and experience lesser shear flow. In this study short carbon fiber (CF reinforced copper matrix composite was developed by PIM process. Two copper composite feedstock formulations were prepared having 5 vol% and 10 vol% CFs and a wax based binder system. Fiber orientation was controlled during injection molding by using a modified mold that has a diverging sprue. The sprue creates converging flow when feedstock enters into the mold cavity. Fiber orientation was analysed after molding using FESEM. The orientation of fibers can be controlled by controlling flow of feedstock into the mold.

  10. Influence of Fiber Orientation on Single-Point Cutting Fracture Behavior of Carbon-Fiber/Epoxy Prepreg Sheets

    Directory of Open Access Journals (Sweden)

    Yingying Wei

    2015-10-01

    Full Text Available The purpose of this article is to investigate the influences of carbon fibers on the fracture mechanism of carbon fibers both in macroscopic view and microscopic view by using single-point flying cutting method. Cutting tools with three different materials were used in this research, namely, PCD (polycrystalline diamond tool, CVD (chemical vapor deposition diamond thin film coated carbide tool and uncoated carbide tool. The influence of fiber orientation on the cutting force and fracture topography were analyzed and conclusions were drawn that cutting forces are not affected by cutting speeds but significantly influenced by the fiber orientation. Cutting forces presented smaller values in the fiber orientation of 0/180° and 15/165° but the highest one in 30/150°. The fracture mechanism of carbon fibers was studied in different cutting conditions such as 0° orientation angle, 90° orientation angle, orientation angles along fiber direction, and orientation angles inverse to the fiber direction. In addition, a prediction model on the cutting defects of carbon fiber reinforced plastic was established based on acoustic emission (AE signals.

  11. Impacts of fiber orientation and milling on observed crystallinity in jack pine

    Science.gov (United States)

    Umesh P. Agarwal; Sally A. Ralph; Richard S. Reiner; Roderquita K. Moore; Carlos Baez

    2014-01-01

    Influences of fiber orientation and milling on wood cellulose crystallinity were studied using jack pine wood. The fiber orientation effects were measured by sampling rectangular wood blocks in radial, tangential, and cross-sectional orientations. The influence of milling was studied by analyzing the unsieved and sieved milled wood fractions (all

  12. 3D DIRECTIONAL MATHEMATICAL MORPHOLOGY FOR ANALYSIS OF FIBER ORIENTATIONS

    Directory of Open Access Journals (Sweden)

    Hellen Altendorf

    2011-05-01

    Full Text Available In this paper we present algorithms for measuring local characteristics of random fiber systems. The calculation of the local directions and radii is based on directional distance transforms and evaluation of the inertia moments and axes of the resulting extremities of the centralized, directed chords. The method provides continuous results while minimizing the runtime by using few sampled directions. Furthermore several steps of improvement for the computation of orientation and radius information are presented. The algorithms are evaluated using synthetic data and applied to images of realmicrostructures obtained by computer tomography.

  13. Research on the behavior of fiber orientation probability distribution function in the planar flows

    Institute of Scientific and Technical Information of China (English)

    ZHOU Kun; LIN Jian-zhong

    2005-01-01

    The equation of two-dimensional fiber direction vector was solved theoretically to give the fiber orientation distribution in simple shear flow, flow with two direction shears, extensional flow and arbitrary planar incompressible flow. The Fokker-Planck equation was solved numerically to validify the theoretical solutions. The stable orientation and orientation period of fiber were obtained. The results showed that the fiber orientation distribution is dependent on the relative not absolute magnitude of the matrix rate-of-strain of flow. The effect of fiber aspect ratio on the orientation distribution of fiber is insignificant in most conditions except the simple shear case. It was proved that the results for a planar flow could be generalized to the case of 3-D fiber direction vector.

  14. Distribution and Orientation of Carbon Fibers in Polylactic Acid Parts Produced by Fused Deposition Modeling

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; W. Gutmann, Ingomar; Koch, Thomas

    2016-01-01

    The aim of this paper is the understanding of the fiber orientation by investigations in respect to the inner configuration of a polylactic acid matrix reinforced with short carbon fibers after a fused deposition modeling extrusion process. The final parts were analyzed by X-ray, tomography, and ......, and magnetic resonance imaging allowing a resolved orientation of the fibers and distribution within the part. The research contributes to the understanding of the fiber orientation and fiber reinforcement of fused deposition modeling parts in additive manufacturing....

  15. Orientation-Dependent Displacement Sensor Using an Inner Cladding Fiber Bragg Grating.

    Science.gov (United States)

    Yang, Tingting; Qiao, Xueguang; Rong, Qiangzhou; Bao, Weijia

    2016-09-11

    An orientation-dependent displacement sensor based on grating inscription over a fiber core and inner cladding has been demonstrated. The device comprises a short piece of multi-cladding fiber sandwiched between two standard single-mode fibers (SMFs). The grating structure is fabricated by a femtosecond laser side-illumination technique. Two well-defined resonances are achieved by the downstream both core and cladding fiber Bragg gratings (FBGs). The cladding resonance presents fiber bending dependence, together with a strong orientation dependence because of asymmetrical distribution of the "cladding" FBG along the fiber cross-section.

  16. Effects of mold geometry on fiber orientation of powder injection molded metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Aslam, Muhammad, E-mail: klaira73@gmail.com; Altaf, Khurram, E-mail: khurram.altaf@petronas.com.my; Shirazi, Irfan, E-mail: irfanshirazi@hotmail.com [Mechanical Engineering Universiti Teknologi PETRONAS Malaysia (Malaysia)

    2015-07-22

    Fiber orientations in metal matrix composites have significant effect on improving tensile properties. Control of fiber orientations in metal injection molded metal composites is a difficult task. In this study, two mold cavities of dimensions 6x6x90 mm and 10x20x180 mm were used for comparison of fiber orientation in injection molded metal composites test parts. In both mold cavities, convergent and divergent flows were developed by modifying the sprue dimensions. Scanning electron microscope (SEM) was used to examine the fiber orientations within the test samples. The results showed highly aligned fiber in injection molded test bars developed from the convergent melt flow. Random orientation of fibers was noted in the composites test bars produced from divergent melt flow.

  17. Science Letters: Research on 3D fiber orientation distribution in arbitrary planar flows

    Institute of Scientific and Technical Information of China (English)

    ZHOU Kun; LIN Jian-zhong

    2007-01-01

    A non-stretchable fiber rotation in planar flows has been solved. The fiber will rotate periodically or run to the asymptotical direction decided by a discriminant defined in the paper involving the fiber aspect ratio and the flow characteristics.Subsequently the fiber orientation distribution is derived directly without the bother of solving the Fokker-Planck equation. The research clearly indicates the overall configuration of a fiber rotation movement in planar flows.

  18. Orientation-Dependent Displacement Sensor Using an Inner Cladding Fiber Bragg Grating

    OpenAIRE

    2016-01-01

    An orientation-dependent displacement sensor based on grating inscription over a fiber core and inner cladding has been demonstrated. The device comprises a short piece of multi-cladding fiber sandwiched between two standard single-mode fibers (SMFs). The grating structure is fabricated by a femtosecond laser side-illumination technique. Two well-defined resonances are achieved by the downstream both core and cladding fiber Bragg gratings (FBGs). The cladding resonance presents fiber bending ...

  19. Modeling and Simulation of Fiber Orientation in Injection Molding of Polymer Composites

    Directory of Open Access Journals (Sweden)

    Jang Min Park

    2011-01-01

    Full Text Available We review the fundamental modeling and numerical simulation for a prediction of fiber orientation during injection molding process of polymer composite. In general, the simulation of fiber orientation involves coupled analysis of flow, temperature, moving free surface, and fiber kinematics. For the governing equation of the flow, Hele-Shaw flow model along with the generalized Newtonian constitutive model has been widely used. The kinematics of a group of fibers is described in terms of the second-order fiber orientation tensor. Folgar-Tucker model and recent fiber kinematics models such as a slow orientation model are discussed. Also various closure approximations are reviewed. Therefore, the coupled numerical methods are needed due to the above complex problems. We review several well-established methods such as a finite-element/finite-different hybrid scheme for Hele-Shaw flow model and a finite element method for a general three-dimensional flow model.

  20. Mapping 3D fiber orientation in tissue using dual-angle optical polarization tractography.

    Science.gov (United States)

    Wang, Y; Ravanfar, M; Zhang, K; Duan, D; Yao, G

    2016-10-01

    Optical polarization tractography (OPT) has recently been applied to map fiber organization in the heart, skeletal muscle, and arterial vessel wall with high resolution. The fiber orientation measured in OPT represents the 2D projected fiber angle in a plane that is perpendicular to the incident light. We report here a dual-angle extension of the OPT technology to measure the actual 3D fiber orientation in tissue. This method was first verified by imaging the murine extensor digitorum muscle placed at various known orientations in space. The accuracy of the method was further studied by analyzing the 3D fiber orientation of the mouse tibialis anterior muscle. Finally we showed that dual-angle OPT successfully revealed the unique 3D "arcade" fiber structure in the bovine articular cartilage.

  1. A new method for fiber orientation distribution in a planar contracting turbulent flow

    Directory of Open Access Journals (Sweden)

    Yang Wei

    2012-01-01

    Full Text Available A new Euler model is proposed to predict fiber orientation distribution at high Reynolds number in a dilute planar contraction. The model mainly accounts for the evolution of mean velocity and turbulence-induced rotational diffusion coefficient along the contraction. It is shown that the new model, as the function of local turbulent dissipation rate, fiber length, and fluid viscosity, can reflect the subtle change of fiber orientation accurately.

  2. Influence of Fiber Orientation on Single-Point Cutting Fracture Behavior of Carbon-Fiber/Epoxy Prepreg Sheets

    OpenAIRE

    2015-01-01

    The purpose of this article is to investigate the influences of carbon fibers on the fracture mechanism of carbon fibers both in macroscopic view and microscopic view by using single-point flying cutting method. Cutting tools with three different materials were used in this research, namely, PCD (polycrystalline diamond) tool, CVD (chemical vapor deposition) diamond thin film coated carbide tool and uncoated carbide tool. The influence of fiber orientation on the cutting force and fracture to...

  3. Preparation of oriented linear copper fiber sintered felt and its performance

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Long metal fibers were manufactured in horizontal lathe with a multi-tooth tool. Based on the coarse antler surface structure of copper fibers, a new sintering technology was put forward to manufacture a kind of oriented linear copper fiber sintered felt. The sintering mechanism of oriented linear copper fiber sintered felt was studied. Compared with sintered copper-wire felt, the characteristics of sintered copper-fiber felts were analyzed in details. Owing to the coarse antler surface structure of copper fibers,oriented linear copper-fiber felt was sintered under the condition of micro/nano scale range, and copper fibers easily bonded together in the sintering process. Microchannels with micro-scale coarse antler surface structure were constructed. These characters give oriented linear copper fiber felt some new merits: high filtration accuracy, high flow capability, low resistance loss, good capability to resistance pressure, stable and uniform pore, high specific surface area. The properties of oriented linear copper fiber sintered felt were analyzed.

  4. Effects of Environment On Creep Behavior of Nextel720/Alumina-Mullite Ceramic Composite With 45 Deg. Fiber Orientation at 1200 Deg. C

    Science.gov (United States)

    2009-03-01

    the 787 Dreamliner , scheduled for delivery in 2010, will be composites [2]. Ceramic matrix composites (CMCs), capable of maintaining excellent...appearance in commercial airplanes with the introduction of the Boeing 707 in the 1950s. Today, composites make up a large percentage of aircraft...structural components. Composites comprise 9% of the aircraft structural weight in the Boeing 777. Boeing is predicting that 50% of the material used on

  5. Determining cardiac fiber orientation using FSL and registered ultrasound/DTI volumes

    Science.gov (United States)

    Dormer, James; Qin, Xulei; Shen, Ming; Wang, Silun; Zhang, Xiaodong; Jiang, Rong; Wagner, Mary B.; Fei, Baowei

    2016-04-01

    Accurate extraction of cardiac fiber orientation from diffusion tensor imaging is important for determining heart structure and function. However, the acquisition of magnetic resonance (MR) diffusion tensor images is costly and time consuming. By comparison, cardiac ultrasound imaging is rapid and relatively inexpensive, but it lacks the capability to directly measure fiber orientations. In order to create a detailed heart model from ultrasound data, a three-dimensional (3D) diffusion tensor imaging (DTI) with known fiber orientations can be registered to an ultrasound volume through a geometric mask. After registration, the cardiac orientations from the template DTI can be mapped to the heart using a deformable transformation field. This process depends heavily on accurate fiber orientation extraction from the DTI. In this study, we use the FMRIB Software Library (FSL) to determine cardiac fiber orientations in diffusion weighted images. For the registration between ultrasound and MRI volumes, we achieved an average Dice similarity coefficient (DSC) of 81.6+/-2.1%. For the estimation of fiber orientations from the proposed method, we achieved an acute angle error (AAE) of 22.7+/-3.1° as compared to the direct measurements from DTI. This work provides a new approach to generate cardiac fiber orientation that may be used for many cardiac applications.

  6. Automatic estimation of retinal nerve fiber bundle orientation in SD-OCT images using a structure-oriented smoothing filter

    Science.gov (United States)

    Ghafaryasl, Babak; Baart, Robert; de Boer, Johannes F.; Vermeer, Koenraad A.; van Vliet, Lucas J.

    2017-02-01

    Optical coherence tomography (OCT) yields high-resolution, three-dimensional images of the retina. A better understanding of retinal nerve fiber bundle (RNFB) trajectories in combination with visual field data may be used for future diagnosis and monitoring of glaucoma. However, manual tracing of these bundles is a tedious task. In this work, we present an automatic technique to estimate the orientation of RNFBs from volumetric OCT scans. Our method consists of several steps, starting from automatic segmentation of the RNFL. Then, a stack of en face images around the posterior nerve fiber layer interface was extracted. The image showing the best visibility of RNFB trajectories was selected for further processing. After denoising the selected en face image, a semblance structure-oriented filter was applied to probe the strength of local linear structure in a discrete set of orientations creating an orientation space. Gaussian filtering along the orientation axis in this space is used to find the dominant orientation. Next, a confidence map was created to supplement the estimated orientation. This confidence map was used as pixel weight in normalized convolution to regularize the semblance filter response after which a new orientation estimate can be obtained. Finally, after several iterations an orientation field corresponding to the strongest local orientation was obtained. The RNFB orientations of six macular scans from three subjects were estimated. For all scans, visual inspection shows a good agreement between the estimated orientation fields and the RNFB trajectories in the en face images. Additionally, a good correlation between the orientation fields of two scans of the same subject was observed. Our method was also applied to a larger field of view around the macula. Manual tracing of the RNFB trajectories shows a good agreement with the automatically obtained streamlines obtained by fiber tracking.

  7. Crystalline Structures and Properties of Uniaxial Oriented Poly(ethylene chlorotrifluoroethylene Fiber

    Directory of Open Access Journals (Sweden)

    PAN Jian

    2016-07-01

    Full Text Available Uniaxial oriented poly (ethylene chlorotrifluoroethylene (ECTFE fibers were prepared by the melt spinning method using ECTFE resin as the fiber-forming polymer. The crystal structures,thermal and mechanical properties and creep resistance of the prepared fibers were analyzed by X-ray diffraction (XRD,differential scanning calorimetry (DSC,mechanical and creep performance testing,etc. Results show that, the uniaxial oriented ECTFE fibers have favourable crystallization property. Their crystalline structures belong to hexagonal system,the degree of crystalline orientation is about 90%. The uniaxial oriented ECTFE fibers have excellent mechanical properties,thermostability,creep resistance and chemical corrosion resistance (such as acid,alkali,strong oxidizing reagents,organic reagents,etc.

  8. Direct Numerical Simulation of Concentration and Orientation Distribution of Fibers in a Mixing Layer

    Directory of Open Access Journals (Sweden)

    Kun Zhou

    2013-01-01

    Full Text Available The concentration and orientation of suspended fibers in a mixing layer are investigated numerically. Two cases (diffusive and nondiffusive are investigated for the fiber concentration distribution. The fine structures of the instantaneous distributions under these two cases are very different due to molecular diffusion. Sharp front of concentration is observed in the nondiffusive case. However, there is no obvious difference in the mean concentration between the two cases. With regard to the orientation, a fiber may rotate periodically or approach an asymptotic orientation, which is determined by a determinant defined with the stain rate. The symmetric part of the strain rate tends to make a fiber align to an asymptotic orientation, while the antisymmetric part drives a fiber to rotate. When a fluid parcel passes through a region with relatively high shear rate, fibers carried by the fluid parcel are most likely to rotate incessantly. On the other hand, in the region of relatively high extension rate, fibers tend to align to some asymptotic orientation. Generally, fibers tend to align with the shear plane. This fact has significant implications in predicting the rheological properties of fiber suspension flows.

  9. Rapid three-dimensional quantification of voxel-wise collagen fiber orientation.

    Science.gov (United States)

    Liu, Zhiyi; Quinn, Kyle P; Speroni, Lucia; Arendt, Lisa; Kuperwasser, Charlotte; Sonnenschein, Carlos; Soto, Ana M; Georgakoudi, Irene

    2015-07-01

    Defining fiber orientation at each voxel within a 3D biomedical image stack is potentially useful for a variety of applications, including cancer, wound healing and tissue regeneration. Current methods are typically computationally intensive or inaccurate. Herein, we present a 3D weighted orientation vector summation algorithm, which is a generalization of a previously reported 2D vector summation technique aimed at quantifying collagen fiber orientations simultaneously at each voxel of an image stack. As a result, voxel-wise fiber orientation information with 4° to 5° accuracy can be determined, and the computational time required to analyze a typical stack with the size of 512x512x100 voxels is less than 5 min. Thus, this technique enables the practical extraction of voxel-specific orientation data for characterizing structural anisotropy in 3D specimens. As examples, we use this approach to characterize the fiber organization in an excised mouse mammary gland and a 3D breast tissue model.

  10. Influence of Synthetic Fibers Angle Orientation on Bending Properties of Composite Plywood

    Directory of Open Access Journals (Sweden)

    Mladen Brezović

    2010-12-01

    Full Text Available This paper presents the results of research on carbon fiber angle orientation and quantity of carbon fi bers in yarn on bending properties of plywood. For that purpose the specimens have been defined as multilayer composites made from carbon fibers and veneer. Carbon fibers were inserted in the second and third glue line of the composite with angle variation of 15°. Stresses and strain were analyzed in significant layers together with displacement of the whole composite plate. The influence of carbon fiber angle orientation on properties of the composite (amount of stresses and related strains was significant. The best results have been achieved with carbon fiber angle of 0°, and bidirectional carbon fiber type (BCF with the orientation angle of 90°. The lowest values have been achieved with carbon fiber angle of 65° (unidirectional carbon fibers-UCF, and bidirectional carbon fiber type (BCF with the orientation angle of 45°. Greater quantity of carbon fibers per one yarn has positive influence on decrease of stresses and strains in veneer layers and provides better stiffness of plywood.

  11. Prediction of fiber orientation in injection-molded parts using three-dimensional simulations

    Science.gov (United States)

    Wang, Jin; Cook, Peter; Bakharev, Alex; Costa, Franco; Astbury, David

    2016-03-01

    The Folgar-Tucker (F-T) model is widely used in most commercial software packages and research programs to predict the fiber orientation distribution in injection-molded fiber-reinforced composites. However, experimental measurements reveal that the F-T model normally results in much higher fiber alignment than observed because it tends to over-predict the orientation kinetics. The Reduced Strain Closure (RSC) model was developed, based on the F-T model, to capture the slow orientation kinetics in an objective fashion. Previous studies demonstrate that t he RSC model yields good agreement of fiber orientation with experimental measurements in shell element simulations using the Hele-Shaw flow approximation. This paper focuses on the RSC model in three-dimensional finite element simulations. The fiber orientation predictions were compared to the orientation measurements in a number of injection-molded parts of various shapes and dimensions and molded with various injection speeds. The RSC model is able to capture the orientation distribution through the part thickness and the average orientation trends along the flow length without the need to tailor the inlet orientation condition to pre-existing data.

  12. Research on the orientation distribution of fibers immersed in a pipe flow

    Institute of Scientific and Technical Information of China (English)

    林建忠; 张卫峰; 王叶龙

    2002-01-01

    The computed orientation distribution of fibers immersed in laminar pipe flows showed that the longitudinal distributions are wide for small Reynolds numbers and become narrower with increasing Re. For low Re number, the axial orientation distributions are broad with almost no preferred orientations. For high Re number, the axial distribution becomes narrow, with sharp maxima. The mean values of the longitudinal orientation depend strongly on the Re number. The computed results are in qualitative agreement with relevant experimental results.

  13. Mathematical model of fiber orientation in anisotropic fascia layers at large displacements.

    Science.gov (United States)

    Chaudhry, Hans; Max, Roman; Antonio, Stecco; Findley, Thomas

    2012-04-01

    A mathematical model is developed to determine the relationship between stretch and the orientation of fibers in the fascia. The transversely isotropic stress- strain relation for large displacements valid for the human fascia reinforced by the collagen fibers is employed. The relation between the orientation of fibers in the un-deformed and deformed state depending upon the stretch is plotted. It is observed that for greater fiber angle orientation, the fibers are more resistant to reorientation as the fascia is stretched longitudinally. It is also concluded that the reinforced fascia will always be in tension as the stretch is applied. However, we suggest future research to resolve the tension and compression issues in fascia.

  14. EFFECTS OF DEFORMATION-INDUCED ORIENTATION ON CYCLIZATION AND OXIDATION OF POLYACRYLONITRILE FIBERS DURING STABILIZATION PROCESS

    Institute of Scientific and Technical Information of China (English)

    Jie Liu; Feng Lian; Zhao-kun Ma; Jie-ying Liang

    2012-01-01

    Orientation of copolymer polyacrylonitrile (PAN) chains during their deformation prior to stabilization and the further effect on the stabilization were investigated in detail.Results reveal that the orientation of PAN chains presents a saturation point of 69.51% when the deformation ratio reaches approximately 1.07,meanwhile the cyclization rather than the oxidation has a stronger dependence on the orientation of PAN chains during stabilization.The cyclization is facilitated that the cyclization degree is increasing while the activation energy is decreasing obviously as a consequence of the developing orientation of PAN fibers before the saturation point; however,it is restrained during the further deformation of PAN fibers after the point.The resulting carbon fibers obtained from the PAN fibers prepared at the saturation point possess the highest mechanical properties of 4.07 GPa in tensile strength and 249.0 GPa in tensile modulus.

  15. Effects of chamber shape and fiber orientation on relations between fiber dynamics and chamber dynamics.

    Science.gov (United States)

    Regen, D M

    1988-01-01

    The function of a chamber depends on its hydrodynamic properties: isometric pressures it can exert in the operating range of distensions, compliances in the operating range of distensions, and wall-displacement resistances in the operating range of distensions. Wall-displacement resistance is the departure of pressure from isometric pressure relative to rate of cavity-volume change. The dependence of pressure on average stress and wall/cavity volume ratio is indifferent to chamber shape, which suggests that the volume-based compliance-elastance and resistance-viscosity equations would be only moderately shape dependent. The present study shows that this supposition is correct. If the wall is thin, these relations are shape indifferent. At higher wall/cavity volume ratio, cylindricity increases slightly the P-V-curve slope relative to elastance and either increases slightly or does not affect resistance relative to viscosity. The compliance-elastance and resistance-viscosity relations also depend only slightly on fiber orientation. Therefore, with the sphere equations, one can account accurately for normal and abnormal function of a prolate spheroid in terms of volume dimensions of the wall and apparent average fiber properties.

  16. Numerical research on the 3D fiber orientation distribution in arbitrary planar flows

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The fiber orientation distribution in a fiber suspension flow was investigated by a finite difference scheme in spherical coordinates. The diffusivity was transformed between Cartesian and spherical coordinates through tensor analysis to obtain efficiency. It is found that under simple shear flow condition the diffusivity in the azimuthal direction, Dry, has greater effect on the orientation distribution than that in the colatitude direction, Drθθ.

  17. The characteristic of unsaturated polyester resin wettability toward glass fiber orientation, density and surface treatment

    Directory of Open Access Journals (Sweden)

    Saputra Asep H.

    2017-01-01

    Full Text Available Wettability of composite is one of key to increase mechanical properties of composite that affected by structure of reinforcement and type of resin used. Therefore, this research focused on the effect of orientation, density and surface treatment on fiber to the characteristic of composite’s wettability, which is observed by contact angle and wetting time. The fiber used in this research is fiberglass, and the method for contact angle measurement is direct observation from the camera recorder and the data record will be processed and analyzed by using image processing method. The result for those variations can be obtained from the relation of variations toward contact angle and wetting time. According to result of research, fiber with orientation 45°/45° gives lower contact angle but longer wetting time than fiber with orientation 0°/90°. For orientation 45°/45°, the differences in wetting time is 15 second longer than orientation 0°/90°. In case of fiber density, the sheet with fiber density of 900 has 7 second faster for wetting time than sheet with fiber density of 1250. The surface treatment with NaOH 5% can accelerate the wetting time until 10 second.

  18. Mapping cardiac fiber orientations from high-resolution DTI to high-frequency 3D ultrasound

    Science.gov (United States)

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Wagner, Mary B.; Fei, Baowei

    2014-03-01

    The orientation of cardiac fibers affects the anatomical, mechanical, and electrophysiological properties of the heart. Although echocardiography is the most common imaging modality in clinical cardiac examination, it can only provide the cardiac geometry or motion information without cardiac fiber orientations. If the patient's cardiac fiber orientations can be mapped to his/her echocardiography images in clinical examinations, it may provide quantitative measures for diagnosis, personalized modeling, and image-guided cardiac therapies. Therefore, this project addresses the feasibility of mapping personalized cardiac fiber orientations to three-dimensional (3D) ultrasound image volumes. First, the geometry of the heart extracted from the MRI is translated to 3D ultrasound by rigid and deformable registration. Deformation fields between both geometries from MRI and ultrasound are obtained after registration. Three different deformable registration methods were utilized for the MRI-ultrasound registration. Finally, the cardiac fiber orientations imaged by DTI are mapped to ultrasound volumes based on the extracted deformation fields. Moreover, this study also demonstrated the ability to simulate electricity activations during the cardiac resynchronization therapy (CRT) process. The proposed method has been validated in two rat hearts and three canine hearts. After MRI/ultrasound image registration, the Dice similarity scores were more than 90% and the corresponding target errors were less than 0.25 mm. This proposed approach can provide cardiac fiber orientations to ultrasound images and can have a variety of potential applications in cardiac imaging.

  19. Incorporation of experimentally-derived fiber orientation into a structural constitutive model for planar collagenous tissues.

    Science.gov (United States)

    Sacks, Michael S

    2003-04-01

    Structural constitutive models integrate information on tissue composition and structure, avoiding ambiguities in material characterization. However, critical structural information (such as fiber orientation) must be modeled using assumed statistical distributions, with the distribution parameters estimated from fits to the mechanical test data. Thus, full realization of structural approaches continues to be limited without direct quantitative structural information for direct implementation or to validate model predictions. In the present study, fiber orientation information obtained using small angle light scattering (SALS) was directly incorporated into a structural constitutive model based on work by Lanir (J. Biomech., v. 16, pp. 1-12, 1983). Demonstration of the model was performed using existing biaxial mechanical and fiber orientation data for native bovine pericardium (Sacks and Chuong, ABME, v.26, pp. 892-902, 1998). The structural constitutive model accurately predicted the complete measured biaxial mechanical response. An important aspect of this approach is that only a single equibiaxial test to determine the effective fiber stress-strain response and the SALS-derived fiber orientation distribution were required to determine the complete planar biaxial mechanical response. Changes in collagen fiber crimp under equibiaxial strain suggest that, at the meso-scale, fiber deformations follow the global tissue strains. This result supports the assumption of affine strain to estimate the fiber strains. However, future evaluations will have to be performed for tissue subjected to a wider range of strain to more fully validate the current approach.

  20. Distribution and Orientation of Carbon Fibers in Polylactic Acid Parts Produced by Fused Deposition Modeling

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; W. Gutmann, Ingomar; Koch, Thomas

    2016-01-01

    The aim of this paper is the understanding of the fiber orientation by investigations in respect to the inner configuration of a polylactic acid matrix reinforced with short carbon fibers after a fused deposition modeling extrusion process. The final parts were analyzed by X-ray, tomography, and ...

  1. ORIENTATION OF MOLECULAR GROUPS IN CROSS SECTION OF POLYAMIDE-6 FIBER BY INFRARED ATTENUATED TOTAL REFLECTION DICHROISM STUDIES

    Institute of Scientific and Technical Information of China (English)

    SHEN Deyan; ZHANG Shengqing

    1987-01-01

    The polymer fiber usually possess typical uniaxial orientation. The molecular chains are symmetrically distributed around fiber axis. In this work, the orientation of molecular groups in the cross section of polyamide-6 fiber has been measured by using IR ATR method. The results indicated that the polyamide-6fiber mainly contains α-crystalline form. The direction of hydrogen bonds of amide groups is predominately parallel with the surface in the cross section of the fiber.

  2. Influence of Synthetic Fibers Angle Orientation on Bending Properties of Composite Plywood

    OpenAIRE

    Mladen Brezović; Jaroslav Kljak; Stjepan Pervan; Alan Antonović

    2010-01-01

    This paper presents the results of research on carbon fiber angle orientation and quantity of carbon fi bers in yarn on bending properties of plywood. For that purpose the specimens have been defined as multilayer composites made from carbon fibers and veneer. Carbon fibers were inserted in the second and third glue line of the composite with angle variation of 15°. Stresses and strain were analyzed in significant layers together with displacement of the whole composite plate. The influence o...

  3. Directed Biosynthesis of Oriented Crystalline Cellulose for Advanced Composite Fibers

    Science.gov (United States)

    2012-05-03

    thiamin hydrochloride 0.4 calcium pantothenate 0.2 n = 2 10 Riboflavin 0.2 p-amino benzoic acid 0.2 folic acid 0.0002 D-biotin 0.0002 The... knowledge gained in this work will be applied toward developing techniques to produce carbon fibers and other novel composite fibers with high structural...and green, renewable processing. The knowledge gained in this work will be applied toward developing techniques to produce carbon fibers and other

  4. SOVIET TRENDS IN ORIENTED GLASS-FIBER REINFORCED PLASTICS

    Science.gov (United States)

    GLASS TEXTILES, *PLASTICS, *REINFORCING MATERIALS, ADHESION, BINDERS, DEFORMATION, ELASTIC PROPERTIES, EPOXY RESINS , FIBERS, PHYSICAL PROPERTIES, POLYMERS, PROCESSING, SILICATES, STYRENES, TEXTILES, VISCOSITY

  5. Three-dimensional fiber segment orientation distribution using X-ray microtomography.

    Science.gov (United States)

    Tausif, Muhammad; Duffy, Brian; Grishanov, Sergei; Carr, Hamish; Russell, Stephen J

    2014-08-01

    The orientation of fibers in assemblies such as nonwovens has a major influence on the anisotropy of properties of the bulk structure and is strongly influenced by the processes used to manufacture the fabric. To build a detailed understanding of a fabric's geometry and architecture it is important that fiber orientation in three dimensions is evaluated since out-of-plane orientations may also contribute to the physical properties of the fabric. In this study, a technique for measuring fiber segment orientation as proposed by Eberhardt and Clarke is implemented and experimentally studied based on analysis of X-ray computed microtomographic data. Fiber segment orientation distributions were extracted from volumetric X-ray microtomography data sets of hydroentangled nonwoven fabrics manufactured from parallel-laid, cross-laid, and air-laid webs. Spherical coordinates represented the orientation of individual fibers. Physical testing of the samples by means of zero-span tensile testing and z-directional tensile testing was employed to compare with the computed results.

  6. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    OpenAIRE

    2011-01-01

    Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens. The effect of processing, melt viscosity and fiber type on the fiber length was investigated. The lengths of fully processed fibers were determined by dissolving the matrix and measuring the length of the...

  7. A new solid particle erosion model for oriented fiber composite materials

    Directory of Open Access Journals (Sweden)

    Valeriu DRAGAN

    2014-03-01

    Full Text Available The work describes a new model of erosion estimation equation which factors in both the impingement angle α and the fiber orientation angle β. Two examples of particular erosion equations are presented, for carbon fiber as well as for glass fiber in epoxidic matrix. Our methods are semi-empirical meaning that the general shape of the erosion equation is maintained while specific material coefficients must be determined for each of the matrix-fiber combination. As showed in the paper, the proposed model correlates well with the experimental data available in the literature. The work is significant since it provides a generalized method for estimating erosion rates for oriented fiber composites which can be further implemented in simulation software in a simple manner.

  8. The orientation field of fibers advected by a two-dimensional chaotic flow

    Science.gov (United States)

    Hejazi, Bardia; Mehlig, Bernhard; Voth, Greg

    2016-11-01

    We examine the orientation of slender fibers advected by a 2D chaotic flow. The orientation field of these fibers show fascinating structures called scar lines, where they rotate by π over short distances. We use the standard map as a convenient model to represent a time-periodic 2D incompressible fluid flow. To understand the fiber orientation field, we consider the stretching field, given by the eigenvalues and eigenvectors of the Cauchy-Green strain tensors. The eigenvector field is strongly aligned with the fibers over almost the entire field, but develops topological singularities at certain points which do not exist in the advected fiber field. The singularities are points that have experienced zero stretching, and the number of such points increases rapidly with time. A key feature of both the fiber orientation and the eigenvector field are the scar lines. We show that certain scar lines form from fluid elements that are initially stretched in one direction and then stretched in an orthogonal direction to cancel the initial stretching. The scar lines that satisfy this condition contain the singularities of the eigenvector field. These scar lines highlight the major differences between the passive director field and the much more widely studied passive scalar field.

  9. Effects of changes in muscle activation level and spine and hip posture on erector spinae fiber orientation.

    Science.gov (United States)

    Harriss, Alexandra B; Brown, Stephen H M

    2015-03-01

    During lumbar flexion, the fiber orientation of the lumbar erector spinae (LES) muscle becomes oriented more along the spine compressive axis. It is unknown how changes in LES activation effect fiber orientation. Ultrasound images of LES were collected during 2 sets of experimental conditions: (1) varying levels of LES activation while lying prone; and (2) varying spine and hip angles while seated. Electromyographic activity and lumbar spine and hip angles were also recorded. As LES activation increased, increases in fiber orientation (signifying increased orientation along the posterior shear axis) were found (Pposture, decreases in fiber orientation were found with full spine flexion and combined spine and hip flexion (Pspine posture both affect LES fiber orientation, thus modifying its ability to protect the spine against anterior shear forces. © 2014 Wiley Periodicals, Inc.

  10. Production and characterization of polyethylene/organoclay oriented fiber

    Science.gov (United States)

    Coppola, B.; Di Maio, L.; Scarfato, P.; Incarnato, L.

    2016-05-01

    The aim of this work was to study the influence of drawing process on the mechanical properties of polyethylene/clay fibers. To this extent, three different PE/clay blends (3, 5 and 10 wt.%) were prepared by melt compounding in a twin-screw extruder. The investigated clay was a commercial organically modified montmorillonite (Dellite 67G). After compounding fibers were produced by a single-screw extruder and drawn at different draw ratios. At increasing draw ratio an increase of elastic modulus and tensile strength was attained. The presence of clay layers increases fibers ductility hindering fibrils formation during the drawing process. Moreover, at increasing clay contents a decrease of tensile strength for high draw ratios was observed. These results demonstrated that the dispersed clay layers can be re-aggregated by the uniaxial flow induced by the drawing process resulting in a decay of mechanical properties at high draw ratios.

  11. Research on the orientation distribution of fibers immersed in a pipe flow

    Institute of Scientific and Technical Information of China (English)

    林建忠; 张卫峰; 等

    2002-01-01

    The computed orientation distribution of fibers immersed in laminar pipe flows showed that the longitudinal distributions are wide for small Reynolds numbers and become narrower with increasing Re.For low Re number.the axial orientation distributions are broad with almost no preferred orientations.For high Re numer,the axial distribution becomes narrow.with sharp maxima..The mean values of the longitudinal orientation depend strongly on the Re number.The computed results are in qualitative agreemernt with relevant experimental results.

  12. Geotechnical behavior of fly ash mixed with randomly oriented fiber inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Kaniraj, S.R.; Gayathri, V. [Indian Institute of Technology, New Delhi (India). Dept. of Civil Engineering

    2003-06-01

    Efforts are underway to improve the use of fly ash in several ways, with the geotechnical utilization also forming an important aspect of these efforts. A number of studies have been conducted recently to investigate the influence of randomly oriented fibers on the geotechnical behavior of coarse grained and fine grained soils. However, very few studies have been carried out on fiber-reinforced fly ash. An experimental study was carried out to investigate the influence of randomly oriented fiber inclusions on the geotechnical behavior of two Indian fly ashes. Polyester fibers of two different types and a constant fiber content of 1% (by dry weight) were used in the experiments. The raw material content of the fibers was 100% recycled plastic waste. This paper presents the results of compaction tests, triaxial shear tests, and other geotechnical characterization tests carried out on the raw and fiber-reinforced fly ashes. The fiber inclusions increased the strength of the raw fly ash specimens and changed their brittle behavior into ductile behavior.

  13. THE ORIENTATION DISTRIBUTION OF FIBER SUSPENSIONS AND ITS EFFECT ON THE CONSTITUTIVE RELATIONSHIP

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ling-xin

    2005-01-01

    The particle orientation distribution of fiber suspensions as well as the bulk stresses of fiber suspensions in the dilute planar converging channel flow in laminar regime, the semi-dilute planar shear flow in laminar regime and dilute planar shear flow in turbulent regime was investigated theoretically and numerically. The experiment on the viscosity of the semi-dilute suspensions of aspect ratio of 10 is performed.

  14. Mesh structure-independent modeling of patient-specific atrial fiber orientation

    Directory of Open Access Journals (Sweden)

    Wachter Andreas

    2015-09-01

    Full Text Available The fiber orientation in the atria has a significant contribution to the electrophysiologic behavior of the heart and to the genesis of arrhythmia. Atrial fiber orientation has a direct effect on excitation propagation, activation patterns and the P-wave. We present a rule-based algorithm that works robustly on different volumetric meshes composed of either isotropic hexahedra or arbitrary tetrahedra as well as on 3-dimensional triangular surface meshes in patient-specific geometric models. This method fosters the understanding of general proarrhythmic mechanisms and enhances patient-specific modeling approaches.

  15. The effect of fiber orientation on volume measurement using conductance catheter techniques.

    Science.gov (United States)

    Thaijiam, C; Gale, T J

    2006-01-01

    Estimation of parallel conductance using the impedance electrode technique is usually done assuming isotropic conditions. This may not be the best solution since the myocardium is an anisotropic material. This paper exposes the effect of fiber orientation for volume measurement using a conductor model with asymmetrical source electrodes. Simulation results show calculated volumes between surrounding materials with and without myocardial fiber orientation included in the model. We plan to extend these study results to the real heart for developing conductance catheter techniques for use in blood volume measurements in the right ventricle.

  16. The control of cell orientation using biodegradable alginate fibers fabricated by near-field electrospinning.

    Science.gov (United States)

    Fuh, Yiin-Kuen; Wu, Yun-Chung; He, Zhe-Yu; Huang, Zih-Ming; Hu, Wei-Wen

    2016-05-01

    For spatially controlling cell alignment, near field electrospinning (NFES) was developed to direct-write alginate fiber patterns. Compared to randomly electrospun fibers, NFES fibers guided the extension of HEK 293T cells and the levels of cell alignment increased with decreasing fiber distances. However, these guiding fibers were unfavorable for cell adhesion and limited cell growth. To preserve cell alignment ability and improve biocompatibility, the stability of patterned alginate fibers was adjusted by regulating the level of ion crosslinking. These partially crosslinked NFES fibers demonstrated parallel line-patterns in the initial stage while gradually degraded with time. The reduction of fiber density increased the available area for cell growth and enhanced cell viability. On the other hand, aligned cells were still found on these degraded patterns, suggesting that cell morphologies were mainly guided during cell seeding. This dynamically controlled fiber pattern system fulfilled the need of controlling cell orientation and biocompatibility, thus was potential to modify scaffold surfaces for tissue engineering application.

  17. Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

    Directory of Open Access Journals (Sweden)

    Amy Y Hsiao

    Full Text Available The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

  18. Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

    Science.gov (United States)

    Hsiao, Amy Y; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

    2015-01-01

    The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

  19. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    DEFF Research Database (Denmark)

    Peltola, Heidi; Madsen, Bo; Joffe, Roberts

    2011-01-01

    Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens...

  20. Heat transfer and pressure drop in a compact pin-fin heat exchanger with pin orientation at 18 deg to the flow direction

    Science.gov (United States)

    Olson, D. A.

    1991-01-01

    The heat transfer and pressure drop characteristics of a novel, compact heat exchanger in helium gas were measured at 3.5 MPa and Reynolds numbers of 450 to 12,000. The pin-fin specimen consisted of pins, 0.51 mm high and spaced 2.03 mm on centers, spanning a channel through which the helium flows; the angle of the row of pins to the flow direction was 18 deg. The specimen was radiatively heated on the top side at heat fluxes up to 74 W/sq cm and insulated on the back side. Correlations were developed for the friction factor and Nusselt number. The Nusselt number compares favorably to those of past studies of staggered pin-fins, when the measured temperatures are extrapolated to the temperature of the wall-fluid interface.

  1. Specific heat of pristine and brominated graphite fibers, composites and HOPG. [Highly Oriented Pyrolytic Graphite

    Science.gov (United States)

    Hung, Ching-Chen; Maciag, Carolyn

    1987-01-01

    Differential scanning calorimetry was used to obtain specific heat values of pristine and brominated P-100 graphite fibers and brominated P-100/epoxy composite as well as pristine and brominated highly oriented pyrolytic graphite (HOPG) for comparison. Based on the experimental results obtained, specific heat values are calculated for several different temperatures, with a standard deviation estimated at 1.4 percent of the average values. The data presented here are useful in designing heat transfer devices (such as airplane de-icing heaters) from bromine fibers.

  2. Effect of polyvinylidene fluoride electrospun fiber orientation on neural stem cell differentiation.

    Science.gov (United States)

    Lins, Luanda C; Wianny, Florence; Livi, Sebastien; Dehay, Colette; Duchet-Rumeau, Jannick; Gérard, Jean-François

    2016-08-29

    Electrospun polymer piezoelectric fibers can be used in neural tissue engineering (NTE) to mimic the physical, biological, and material properties of the native extracellular matrix. In this work, we have developed scaffolds based on polymer fiber architectures for application in NTE. To study the role of such three-dimensional scaffolds, a rotating drum collector was used for electrospinning poly(vinylidene) fluoride (PVDF) polymer at various rotation speeds. The morphology, orientation, polymorphism, as well as the mechanical behavior of the nonaligned and aligned fiber-based architectures were characterized. We have demonstrated that the jet flow and the electrostatic forces generated by electrospinning of PVDF induced local conformation changes which promote the generation of the β-phase. Fiber anisotropy could be a critical feature for the design of suitable scaffolds for NTEs. We thus assessed the impact of PVDF fiber alignment on the behavior of monkey neural stem cells (NSCs). NSCs were seeded on nonaligned and aligned scaffolds and their morphology, adhesion, and differentiation capacities into the neuronal and glial pathways were studied using microscopic techniques. Significant changes in the growth and differentiation capacities of NSCs into neuronal and glial cells as a function of the fiber alignment were evidenced. These results demonstrate that PVDF scaffolds may serve as instructive scaffolds for NSC survival and differentiation, and may be valuable tools for the development of cell- and scaffold-based strategies for neural repair. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  3. Creep Behavior of Oxide/Oxide Composites with Monazite Fiber Coating at 1100 deg C in Air and in Steam Environments

    Science.gov (United States)

    2008-09-01

    tensometer was equipped with 6-inch alumina contact rods and protected by a heat shield to maintain the unit temperatures within the manufacturers...R.J. “Crack deflection in ceramic composites and fiber coating design criteria”. Composites: Part A, 30:521–524, 1999. 20. K.K., Chawla. Ceramic MAtrix...Behavior of NextelTM720/ Alumina (N720/A) Continuous Fiber Ceramic Composite”. Composites Part A: Applied Science and Manufacturing, 37:2029–2040, 2006

  4. Effect of Fiber Orientation Angle on the Failure Mode of Pin Jointed Laminated Composite Plates

    Directory of Open Access Journals (Sweden)

    Kadir TURAN

    2010-02-01

    Full Text Available In this study, the major aim is to investigate change effects of fiber orientation angles on the failure loads and failure modes for the pin jointed laminated composite plates. In the analysis, laminated composite plates with epoxy matrix resin reinforced unidirectional carbon fibers are used. The ply arrangements are chosen [?0]4 and ?; fiber reinforced angle changes from 00 to 900 with 150 increments. The failure load and failure mode are analyzed experimentally and numerically. In the numerical analysis Ansys program is used. In the program, material properties are degraded using APDL code which is written for progressive failure analysis and contains Hashin failure criteria for laminated composite plates. In the experimental study, the maximum failure load for [150]4 laminae cofiguration, 749.917 N and minimum failure load for [600]4, 467.483 N laminae configuration are obtained. A good agreement between experimental and numerical solution is obtained.

  5. Influence of fiber type, fiber mat orientation, and process time on the properties of a wood fiber/polymer composite

    DEFF Research Database (Denmark)

    Plackett, David; Torgilsson, R.; Løgstrup Andersen, T.

    2002-01-01

    A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat, incorporating either mechanically refined or bleached chemi-thermomechanically refined Norway Spruce [Picea abies (L.) Karst] and a bicomponent polymer fiber. The manufacturing technique...... involved pre-compression, contact heating to the process temperature under vacuum and then rapid transfer to the press for consolidation and cooling. Composites were tested to determine response to water or water vapor, porosity, fiber volume fraction and tensile properties. The composites absorbed water...... by the polymer matrix had been maximized within a five-minute heating time. Results also indicated that had been maximized within a five-minute heating time. Results also indicated that porosity was not the key determinant of tensile properties in the composites....

  6. Estimating Fiber Orientation Distribution Functions in 3D-Polarized Light Imaging.

    Science.gov (United States)

    Axer, Markus; Strohmer, Sven; Gräßel, David; Bücker, Oliver; Dohmen, Melanie; Reckfort, Julia; Zilles, Karl; Amunts, Katrin

    2016-01-01

    Research of the human brain connectome requires multiscale approaches derived from independent imaging methods ideally applied to the same object. Hence, comprehensible strategies for data integration across modalities and across scales are essential. We have successfully established a concept to bridge the spatial scales from microscopic fiber orientation measurements based on 3D-Polarized Light Imaging (3D-PLI) to meso- or macroscopic dimensions. By creating orientation distribution functions (pliODFs) from high-resolution vector data via series expansion with spherical harmonics utilizing high performance computing and supercomputing technologies, data fusion with Diffusion Magnetic Resonance Imaging has become feasible, even for a large-scale dataset such as the human brain. Validation of our approach was done effectively by means of two types of datasets that were transferred from fiber orientation maps into pliODFs: simulated 3D-PLI data showing artificial, but clearly defined fiber patterns and real 3D-PLI data derived from sections through the human brain and the brain of a hooded seal.

  7. Quantifying collagen fiber orientation in breast cancer using quantitative phase imaging

    Science.gov (United States)

    Majeed, Hassaan; Okoro, Chukwuemeka; Kajdacsy-Balla, André; Toussaint, Kimani C., Jr.; Popescu, Gabriel

    2017-04-01

    Tumor progression in breast cancer is significantly influenced by its interaction with the surrounding stromal tissue. Specifically, the composition, orientation, and alignment of collagen fibers in tumor-adjacent stroma affect tumor growth and metastasis. Most of the work done on measuring this prognostic marker has involved imaging of collagen fibers using second-harmonic generation microscopy (SHGM), which provides label-free specificity. Here, we show that spatial light interference microscopy (SLIM), a label-free quantitative phase imaging technique, is able to provide information on collagen-fiber orientation that is comparable to that provided by SHGM. Due to its wide-field geometry, the throughput of the SLIM system is much higher than that of SHGM and, because of the linear imaging, the equipment is simpler and significantly less expensive. Our results indicate that SLIM images can be used to extract important prognostic information from collagen fibers in breast tissue, potentially providing a convenient high throughput clinical tool for assessing patient prognosis.

  8. Diffusion tensor imaging fiber tracking with reliable tracking orientation and flexible step size

    Institute of Scientific and Technical Information of China (English)

    Xufeng Yao; Manning Wang; Xinrong Chen; Shengdong Nie; Zhexu Li; Xiaoping Xu; Xuelong Zhang; Zhijian Song

    2013-01-01

    We propose a method of reliable tracking orientation and flexible step size fiber tracking. A new directional strategy was defined to select one optimal tracking orientation from each directional set, which was based on the single-tensor model and the two-tensor model. The directional set of planar voxels contained three tracking directions: two from the two-tensor model and one from the singletensor model. The directional set of linear voxels contained only one principal vector. In addition, a flexible step size, rather than fixable step sizes, was implemented to improve the accuracy of fiber tracking. We used two sets of human data to assess the performance of our method; one was from a healthy volunteer and the other from a patient with low-grade glioma. Results verified that our method was superior to the single-tensor Fiber Assignment by Continuous Tracking and the two-tensor eXtended Streamline Tractography for showing detailed images of fiber bundles.

  9. Spherical finite rate of innovation theory for the recovery of fiber orientations.

    Science.gov (United States)

    Deslauriers-Gauthier, Samuel; Marziliano, Pina

    2012-01-01

    In this paper, we investigate the reconstruction of a signal defined as the sum of K orientations from samples taken with a kernel defined on the 3D rotation group. A potential application is the recovery of fiber orientations in diffusion magnetic resonance imaging. We propose an exact reconstruction algorithm based on the finite rate of innovation theory that makes use of the spherical harmonics representation of the signal. The number of measurements needed for perfect recovery, which may be as low as 3K, depends only on the number of orientations and the bandwidth of the kernel used. Furthermore, the angular resolution of our method does not depend on the number of available measurements. We illustrate the performance of the algorithm using several simulations.

  10. Orientation of aromatic residues in amyloid cores: Structural insights into prion fiber diversity

    KAUST Repository

    Reymer, Anna

    2014-11-17

    Structural conversion of one given protein sequence into different amyloid states, resulting in distinct phenotypes, is one of the most intriguing phenomena of protein biology. Despite great efforts the structural origin of prion diversity remains elusive, mainly because amyloids are insoluble yet noncrystalline and therefore not easily amenable to traditional structural-biology methods. We investigate two different phenotypic prion strains, weak and strong, of yeast translation termination factor Sup35 with respect to angular orientation of tyrosines using polarized light spectroscopy. By applying a combination of alignment methods the degree of fiber orientation can be assessed, which allows a relatively accurate determination of the aromatic ring angles. Surprisingly, the strains show identical average orientations of the tyrosines, which are evenly spread through the amyloid core. Small variations between the two strains are related to the local environment of a fraction of tyrosines outside the core, potentially reflecting differences in fibril packing.

  11. Molecular Orientation in Dry and Hydrated Cellulose Fibers: A Coherent Anti-Stokes Raman Scattering Microscopy Study

    OpenAIRE

    Zimmerley, Maxwell; Younger, Rebecca; Valenton, Tiffany; Oertel, David C.; Ward, Jimmie L.; Potma, Eric O.

    2010-01-01

    Coherent anti-Stokes Raman scattering (CARS) microscopy is combined with spontaneous Raman scattering microspectroscopy and second harmonic generation (SHG) microscopy to interrogate the molecular alignment in dry and hydrated cellulose fibers. Two types of cellulose were investigated: natural cellulose I in cotton fibers and regenerated cellulose II in rayon fibers. On the basis of the orientation of the methylene symmetric stretching vibration, the molecular alignment of cellulose microfibr...

  12. Continual Cell Deformation Induced via Attachment to Oriented Fibers Enhances Fibroblast Cell Migration

    Science.gov (United States)

    Qin, Sisi; Ricotta, Vincent; Simon, Marcia; Clark, Richard A. F.; Rafailovich, Miriam H.

    2015-01-01

    Fibroblast migration is critical to the wound healing process. In vivo, migration occurs on fibrillar substrates, and previous observations have shown that a significant time lag exists before the onset of granulation tissue. We therefore conducted a series of experiments to understand the impact of both fibrillar morphology and migration time. Substrate topography was first shown to have a profound influence. Fibroblasts preferentially attach to fibrillar surfaces, and orient their cytoplasm for maximal contact with the fiber edge. In the case of en-mass cell migration out of an agarose droplet, fibroblasts on flat surfaces emerged with an enhanced velocity, v = 52μm/h, that decreases to the single cell value, v = 28μm/h within 24 hours and remained constant for at least four days. Fibroblasts emerging on fibrillar surfaces emerged with the single cell velocity, which remained constant for the first 24 hours and then increased reaching a plateau with more than twice the initial velocity within the next three days. The focal adhesions were distributed uniformly in cells on flat surfaces, while on the fibrillar surface they were clustered along the cell periphery. Furthermore, the number of focal adhesions for the cells on the flat surfaces remained constant, while it decreased on the fibrillar surface during the next three days. The deformation of the cell nuclei was found to be 50% larger on the fiber surfaces for the first 24 hours. While the mean deformation remained constant on the flat surface, it increased for the next three days by 24% in cells on fibers. On the fourth day, large actin/myosin fibers formed in cells on fibrillar surfaces only and coincided with a change from the standard migration mechanism involving extension of lamellipodia, and retraction of the rear, to one involving strong contractions oriented along the fibers and centered about the nucleus. PMID:25774792

  13. Continual cell deformation induced via attachment to oriented fibers enhances fibroblast cell migration.

    Directory of Open Access Journals (Sweden)

    Sisi Qin

    Full Text Available Fibroblast migration is critical to the wound healing process. In vivo, migration occurs on fibrillar substrates, and previous observations have shown that a significant time lag exists before the onset of granulation tissue. We therefore conducted a series of experiments to understand the impact of both fibrillar morphology and migration time. Substrate topography was first shown to have a profound influence. Fibroblasts preferentially attach to fibrillar surfaces, and orient their cytoplasm for maximal contact with the fiber edge. In the case of en-mass cell migration out of an agarose droplet, fibroblasts on flat surfaces emerged with an enhanced velocity, v = 52μm/h, that decreases to the single cell value, v = 28μm/h within 24 hours and remained constant for at least four days. Fibroblasts emerging on fibrillar surfaces emerged with the single cell velocity, which remained constant for the first 24 hours and then increased reaching a plateau with more than twice the initial velocity within the next three days. The focal adhesions were distributed uniformly in cells on flat surfaces, while on the fibrillar surface they were clustered along the cell periphery. Furthermore, the number of focal adhesions for the cells on the flat surfaces remained constant, while it decreased on the fibrillar surface during the next three days. The deformation of the cell nuclei was found to be 50% larger on the fiber surfaces for the first 24 hours. While the mean deformation remained constant on the flat surface, it increased for the next three days by 24% in cells on fibers. On the fourth day, large actin/myosin fibers formed in cells on fibrillar surfaces only and coincided with a change from the standard migration mechanism involving extension of lamellipodia, and retraction of the rear, to one involving strong contractions oriented along the fibers and centered about the nucleus.

  14. Scanning electron microscopy of collagen fiber orientation in the bone lamellar system in non-decalcified human samples.

    Science.gov (United States)

    Pannarale, L; Braidotti, P; d'Alba, L; Gaudio, E

    1994-01-01

    Previous studies on collagen fiber orientation have led to different interpretations and theories about the fiber arrangement in the lamellar compact bone. The purpose of this investigation was to provide new and more in-depth data on fiber arrangement in the lamellar bone system in order to explain the orientation of the fiber bundles. This was carried out by applying a simple method of preparation which permitted observation of non-decalcified samples. A previously isolated Haversian system was subjected to slow bending up to reaching the fracture point. Hence, the fracture surface was observed by SEM. The same samples were also observed by polarized light microscopy. A significant alternation of fiber orientation in the adjacent lamellae was observed. Different domains of differently oriented fibers were present within the same lamella; conjugating fibers connecting adjacent lamellae were also shown. This method avoided most of the artifacts due to chemical treatment of bone samples. The results can be easily interpreted by means of the same criteria applied in mechanics for the studying of composite materials.

  15. The influence of fiber orientation angle on the impact characteristic of circular aluminum tube reinforced by fiber glass/polyester

    Directory of Open Access Journals (Sweden)

    Kiatipong Komlungkang

    2015-03-01

    Full Text Available This study was aimed to increase the impact resistance of circular tubes reinforced by fiber reinforced plastic (FRP.The tube made of aluminum 6063-T5 with the D/t ratio of 25.40, 29.63, and 42.33. Outside surface of aluminum tube was reinforced by wrapping fiberglass/polyester. The fiber orientation angle were [0]3 , [45]3 , [90]3 , [0/902 ], [45/-452 ], and [90/02 ]. Then, they were tested under impact with cross head of 45 kg and speed of 6.26 m/s in axial direction. The result revealed that the impact resistance of the hybrid tube and aluminum tube trend to increase as the D/t ratio increases and The hybrid tube with wrapped angle of [0/902 ] was maximum mean load and higher than aluminum tube by 50.02, 45.14, and 52.03 % at D/t = 25.40, 29.63, and 42.33 receptively. Failure mode and crush behavior of hybrid tube were also presented and disused in this paper.

  16. Orientation analysis of collagen fibers in healing tendon by using second-harmonic-generation microscopy

    Science.gov (United States)

    Hase, E.; Minamikawa, T.; Sato, K.; Yonekura, D.; Takahashi, M.; Yasui, T.

    2017-02-01

    Tendon rupture is a trauma that is difficult to fully recover from. Therefore, non-destructive and non-invasive evaluation method for the tendon healing is strongly required. In this study, we performed the orientation analysis of collagen fiber in healing tendon by two-dimensional Fourier transform (2D-FT) of SHG image. The extracted 2D-FT power spectra imply the correlation with the degree of the tendon healing. These results indicate that SHG microscopy has a unique potential as a non-destructive and non-invasive indicator of tendon healing.

  17. Conformation and orientation of proteins in various types of silk fibers produced by Nephila clavipes spiders.

    Science.gov (United States)

    Rousseau, Marie-Eve; Lefèvre, Thierry; Pézolet, Michel

    2009-10-12

    Silk fibers harvested from the web, cocoon, and prey wrapping of the spider Nephila clavipes have been studied by polarized Raman spectromicroscopy. The technique is efficient to differentiate the various types of silk by probing monofilaments produced by the major ampullate (MA), minor ampullate (MI), cylindriform, flagelliform, and aciniform glands. The spectra show that the MA, MI, and cylindriform silks belong to the same structural class and are composed of highly oriented beta-sheets (35-37%) with other slightly oriented secondary structures. Spectral markers of particular motifs involved in the beta-sheets have been identified. The flagelliform silk represents a second, very peculiar structural class. It displays a heterogeneous disordered conformation without any preferential orientation. Such characteristics certainly play a role in the large extensibility of this silk. The aciniform silk represents a third class of silk dominated by moderately oriented beta-sheets (approximately 30%) and alpha-helices (approximately 24%). Such a structure seems important in explaining the high toughness of this silk.

  18. Quantification of collagen fiber orientation in human tendons with the coefficient of variation of echogenicity.

    Science.gov (United States)

    Ishigaki, Tomonobu; Kouno, Masahiro; Ikebukuro, Toshihiro; Kubo, Keitaro

    2016-12-08

    The grayscale distribution on the ultrasonic images of tendons may be reduced with alignment of collagen fibers, because ultrasound signal intensity changes with alterations in tendon collagen fiber orientation due to acoustic anisotropy in the tendons. The purpose of this study was to investigate changes in the coefficient of variation (CV) of echogenicity in the Achilles tendon during passive dorsiflexion (the angle task) and isometric plantar flexion (the contraction task). Achilles tendon transverse ultrasonic images were collected from 14 healthy individuals every 10° from 20° to -20° (positive values for plantar flexion) in the angle task and every 10% maximum voluntary contraction (MVC) from 0% to 70% MVC in the contraction task. The CV of echogenicity was measured in each image. In addition, relative changes in the measured variables between the former half (20-0° in the angle task, 0% to 30% MVC in the contraction task) and the latter half (0° to -20° in the angle task, 40% to 70% MVC in the contraction task) of each task were compared. The CV of echogenicity decreased with increases in the dorsiflexion angle and intensity of isometric contractions. Furthermore, relative changes in the CV of echogenicity were greater at more dorsiflexed positions in the angle task and at lower torque levels in the contraction task. These results suggested that decreases in the CV of echogenicity were partially related to the alignment of the tendon collagen fibers with tendon stretching. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. The use of image analysis in evaluation of the fibers orientation in Wood-polymer composites (WPC)

    Science.gov (United States)

    Bednarz, Arkadiusz; Frącz, Wiesław; Janowski, Grzegorz

    2016-12-01

    In this paper a novel way of a digital analysis of fibers orientation with a five-step algorithmwas presented. In the study, a molded piece with a dumbbell shape prepared from wood-polymer composite was used. The injection molding process was examined in experimental and numerical way. Based on the developed mathematical algorithm, a significant compliance of fiber orientation in different areas of the molded piece was obtained. The main aim of thisworkwas fiber orientation analysis of wood-polymer composites. An additional goal of thiswork was the comparison of the results reached in numerical analysis with results obtained from an experiment. The results of this research were important for the scientific and also from the practical point of view. In future works the prepared algorithm could be used to reach optimal parameters of the injection molding process.

  20. Register cardiac fiber orientations from 3D DTI volume to 2D ultrasound image of rat hearts

    Science.gov (United States)

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-03-01

    Two-dimensional (2D) ultrasound or echocardiography is one of the most widely used examinations for the diagnosis of cardiac diseases. However, it only supplies the geometric and structural information of the myocardium. In order to supply more detailed microstructure information of the myocardium, this paper proposes a registration method to map cardiac fiber orientations from three-dimensional (3D) magnetic resonance diffusion tensor imaging (MR-DTI) volume to the 2D ultrasound image. It utilizes a 2D/3D intensity based registration procedure including rigid, log-demons, and affine transformations to search the best similar slice from the template volume. After registration, the cardiac fiber orientations are mapped to the 2D ultrasound image via fiber relocations and reorientations. This method was validated by six images of rat hearts ex vivo. The evaluation results indicated that the final Dice similarity coefficient (DSC) achieved more than 90% after geometric registrations; and the inclination angle errors (IAE) between the mapped fiber orientations and the gold standards were less than 15 degree. This method may provide a practical tool for cardiologists to examine cardiac fiber orientations on ultrasound images and have the potential to supply additional information for diagnosis of cardiac diseases.

  1. The melt-recrystallization behavior of highly oriented α-iPP fibers embedded in a HIPS matrix.

    Science.gov (United States)

    Ye, Liwei; Li, Huihui; Qiu, Zhaobin; Yan, Shouke

    2015-03-21

    The melt-recrystallization behavior of α-iPP fibers embedded in an amorphous HIPS matrix has been studied by means of optical microscopy. The amorphous HIPS serving as a supporter of iPP fibers does not become involved in the nucleation and crystallization process of the molten highly oriented iPP fibers. It also does not provide any birefringence under the optical microscope with crossed polarizers. This enables the study of orientation-induced β-iPP crystallization through a control of the melting status of the fibers. Through melting the fibers at different temperatures above 175 °C and subsequent recrystallization, some β-iPP crystals were always produced. The content of the β-iPP crystal depends strongly on the melting temperature and melting time of the iPP fibers. It was confirmed that melting the iPP fibers at relatively lower temperature, e.g. 176 °C, less amount of β-iPP crystals were observed. The content of β-iPP crystal enhances first with increasing melting temperature and then decreases with further increase of the fiber melting temperature. The β-iPP crystallization is found to be most favorable upon melting the fibers at 178 °C for 2 min. This demonstrates the requirement of a certain chain or chain segment orientation for generating β-iPP crystallization on the one hand, while higher orientation of the iPP chains or chain segments encourages the growth of iPP crystals in the α-form on the other hand. This has been further confirmed by varying the melting time of the fiber at different temperatures, since relaxation of the iPP molecular chains at a fixed temperature is time dependent. Moreover, the complete transformation of α-iPP fibers in some local places into β-iPP crystals implies that the αβ-transition may not be required for the orientation-induced β-iPP crystallization.

  2. Il teatro degli spiriti.

    Directory of Open Access Journals (Sweden)

    Chiara Pussetti

    2013-07-01

    Full Text Available Questo saggio è dedicato a un culto di possessione, in cui tutte ledonne, investite dagli spiriti degli uomini morti prima dell’iniziazione, compiono un percorso iniziatico parallelo a quello maschile, consentendo a queste anime, potenzialmente pericolose, di completare il cammino che non hanno potuto percorrere da vivi e quindi di raggiungere serenamente il mondo dei morti, come antenati protettori del villaggio

  3. Mapping of intramuscular tenderness and muscle fiber orientation of muscles in the beef round.

    Science.gov (United States)

    Senaratne, L S; Calkins, C R; de Mello, A S; Pokharel, S; Hinkle, J B

    2010-09-01

    Intramuscular tenderness variation and muscle fiber orientation of beef M. adductor femoris (AF), M. biceps femoris (BF), M. gracilis (GL), M. pectineus (PT), M. sartorius (SR), M. semimembranosus (SM), M. semitendinosus (SO), M. vastus intermedius (VI), M. vastus medialis (VM), and M. vastus lateralis (VL) were investigated. The USDA Choice boxed beef subprimals were purchased and aged for 14 d from boxed date. The AF, BF, GL, PT, SR, SM, SO, VI, VM, and VL (n = 10 each) were fabricated from subprimals. Crust-frozen AF, BF, SO, SM, and VL were cut into 2.54-cm steaks perpendicular to the long axis and grilled (71 degrees C). The PT, SR, VI, and VM were grilled (71 degrees C) as whole muscles, whereas the GL was grilled after cutting into anterior and posterior regions. Grilled muscles were cut into equal size sections perpendicular to long axis of muscles. Location-specific cores were prepared from each steak/section, and Warner-Bratzler shear force (WBSF) was measured. The muscle fiber orientations of BF, PT, and VI were bipennate, SR and SO were fusiform, and AD, SM, VL, GL, and VM were unipennate. The overall mean WBSF values for BF, SO, AF, SM, PT, SR, GL, VI, VM, and VL were 5.62, 4.86, 4.18, 4.90, 3.76, 4.44, 4.75, 4.78, 4.24, and 6.53 kg, respectively. Based on WBSF values, PT was tender, BF and VL were tough, and VM, VI, SM, GL SR, AF, and SO were intermediate. The first 2 proximal steaks of long head BF were more tender than the rest (P Dry or moist heat oven roasting, as compared with grilling, significantly tenderized SO (P = 0.002) and VL (P beef round.

  4. Oriented growth of poly(m-phenylenediamine) on Calotropis gigantea fiber for rapid adsorption of ciprofloxacin.

    Science.gov (United States)

    Cao, Enjuan; Duan, Wenzhen; Wang, Aiqin; Zheng, Yian

    2017-03-01

    A facile polymerization of m-phenylenediamine (mPD) in methanol/water (50:50, v/v) was performed via conventional chemical oxidative method by using Calotropis gigantea fiber (CGF) as the natural biotemplate. The as-prepared CGF oriented poly(m-phenylenediamine) (PmPD), i.e. CGF-O-PmPD, exhibits a well defined fiber-oriented morphology. The presence of PmPD layer enables CGF-O-PmPD to present roughen surface with N-rich functional groups that can show high performance for the adsorption of ciprofloxacin. The variables affecting the adsorption capacity were systematically investigated, including contact time, initial concentration, initial pH, ion strength, and so forth. The experimental data reveal that with increasing the amount of mPD from 0.2, 0.5 to 2.0 g, the adsorption capacity for ciprofloxacin shows a monotonic decrease, while the adsorption kinetics show a monotonic increase, with the adsorption percentage from >50%, >60% to >70% within 10 s, demonstrating its superfast adsorption kinetics for ciprofloxacin. In addition, an increasing adsorption capacity is observed over the pH range studied, with the adsorption capacity from 0.73 to 6.7 mg g(-1) at pH 2.0 to 64.9-77.3 mg g(-1) at pH 10.0. After five adsorption-desorption cycles, the adsorption capacity of CGF-O-PmPD for ciprofloxacin shows no significant decrease, indicating its excellent reusability and potential application in treating antibiotic-containing wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Process Optimization of Bismaleimide (BMI) Resin Infused Carbon Fiber Composite

    Science.gov (United States)

    Ehrlich, Joshua W.; Tate, LaNetra C.; Cox, Sarah B.; Taylor, Brian J.; Wright, M. Clara; Caraccio, Anne J.; Sampson, Jeffery W.

    2013-01-01

    Bismaleimide (BMI) resins are an attractive new addition to world-wide composite applications. This type of thermosetting polyimide provides several unique characteristics such as excellent physical property retention at elevated temperatures and in wet environments, constant electrical properties over a vast array of temperature settings, and nonflammability properties as well. This makes BMI a popular choice in advance composites and electronics applications [I]. Bismaleimide-2 (BMI-2) resin was used to infuse intermediate modulus 7 (IM7) based carbon fiber. Two panel configurations consisting of 4 plies with [+45deg, 90deg]2 and [0deg]4 orientations were fabricated. For tensile testing, a [90deg]4 configuration was tested by rotating the [0deg]4 configirration to lie orthogonal with the load direction of the test fixture. Curing of the BMI-2/IM7 system utilized an optimal infusion process which focused on the integration of the manufacturer-recommended ramp rates,. hold times, and cure temperatures. Completion of the cure cycle for the BMI-2/IM7 composite yielded a product with multiple surface voids determined through visual and metallographic observation. Although the curing cycle was the same for the three panellayups, the surface voids that remained within the material post-cure were different in abundance, shape, and size. For tensile testing, the [0deg]4 layup had a 19.9% and 21.7% greater average tensile strain performance compared to the [90deg]4 and [+45deg, 90deg, 90deg,-45degg] layups, respectively, at failure. For tensile stress performance, the [0deg]4 layup had a 5.8% and 34.0% greater average performance% than the [90deg]4 and [+45deg, 90deg, 90deg,-45deg] layups.

  6. Analysis of key factors influencing the evaporation performances of an oriented linear cutting copper fiber sintered felt

    Science.gov (United States)

    Pan, Minqiang; Zhong, Yujian

    2017-07-01

    Porous structure can effectively enhance the heat transfer efficiency. A kind of micro vaporizer using the oriented linear cutting copper fiber sintered felt is proposed in this work. Multiple long cutting copper fibers are firstly fabricated with a multi-tooth tool and then sintered together in parallel to form uniform thickness metal fiber sintered felts that provided a characteristic of oriented microchannels. The temperature rise response and thermal conversion efficiency are experimentally investigated to evaluate the influences of porosity, surface structure, feed flow rate and input power on the evaporation characteristics. It is indicated that the temperature rise response of water is mainly affected by input power and feed flow rate. High input power and low feed flow rate present better temperature rise response of water. Porosity rather than surface structure plays an important role in the temperature rise response of water at a relatively high input power. The thermal conversion efficiency is dominated by the input power and surface structure. The oriented linear cutting copper fiber sintered felts for three kinds of porosities show better thermal conversion efficiency than that of the oriented linear copper wire sintered felt when the input power is less than 115 W. All the sintered felts have almost the same performance of thermal conversion at a high input power.

  7. Coupling analysis of non-circular-symmetric modes and design of orientation-insensitive few-mode fiber couplers

    Science.gov (United States)

    Li, Jiaxiong; Du, Jiangbing; Ma, Lin; Li, Ming-Jun; Jiang, Shoulin; Xu, Xiao; He, Zuyuan

    2017-01-01

    We study the coupling between two identical weakly-coupled few-mode fibers based on coupled-mode theory. The coupling behavior of non-circular-symmetric modes, such as LP11 and LP21, is investigated analytically and numerically. By carefully choosing the fiber core separation and coupler length, we can design orientation-insensitive fiber couplers for non-circular-symmetric modes at arbitrary coupling ratios. Based on the design method, we propose an orientation-insensitive two-mode fiber coupler at 850 nm working as a mode multiplexer/demultiplexer for two-mode transmission using standard single-mode fiber. Within the band from 845 to 855 nm, the insertion losses of LP01 and LP11 modes are less than 0.03 dB and 0.24 dB, respectively. When the two-mode fiber coupler is used as mode demultiplexer, the LP01/LP11 and LP11/LP01 extinction ratios in the separated branches are respectively above 12.6 dB and 21.2 dB. Our design method can be extended to two-mode communication or sensing systems at other wavelengths.

  8. Effect of fiber fabric orientation on the flexural monotonic and fatigue behavior of 2D woven ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, N., E-mail: nchawla@asu.edu [Materials Science and Engineering, Arizona State University Tempe, AZ 85287-6106 (United States); Liaw, P.K. [Department of Materials Science and Engineering, University of Tennessee-Knoxville, Knoxville, TN 37996 (United States); Lara-Curzio, E.; Ferber, M.K.; Lowden, R.A. [High Temperature Materials Laboratory, Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2012-11-15

    The effect of fiber fabric orientation, i.e., parallel to loading and perpendicular to the loading axis, on the monotonic and fatigue behavior of plain-weave fiber reinforced SiC matrix laminated composites was investigated. Two composite systems were studied: Nextel 312 (3M Corp.) reinforced SiC and Nicalon (Nippon Carbon Corp.) reinforced SiC, both fabricated by Forced Chemical Vapor Infiltration (FCVI). The behavior of both materials was investigated under monotonic and fatigue loading. Interlaminar and in-plane shear tests were conducted to further correlate shear properties with the effect of fabric orientation, with respect to the loading axis, on the orientation effects in bending. The underlying mechanisms, in monotonic and fatigue loading, were investigated through post-fracture examination using scanning electron microscopy (SEM).

  9. Effects of Crystal Orientation on Cellulose Nanocrystals−Cellulose Acetate Nanocomposite Fibers Prepared by Dry Spinning

    Science.gov (United States)

    Si Chen; Greg Schueneman; R. Byron Pipes; Jeffrey Youngblood; Robert J. Moon

    2014-01-01

    This work presents the development of dry spun cellulose acetate (CA) fibers using cellulose nanocrystals (CNCs) as reinforcements. Increasing amounts of CNCs were dispersed into CA fibers in efforts to improve the tensile strength and elastic modulus of the fiber. A systematic characterization of dispersion of CNCs in the polymer fiber and their effect on the...

  10. Seeing More by Showing Less : Orientation-Dependent Transparency Rendering for Fiber Tractography Visualization

    NARCIS (Netherlands)

    Tax, Chantal M. W.; Chamberland, Maxime; van Stralen, Marijn; Viergever, Max A.; Whittingstall, Kevin; Fortin, David; Descoteaux, Maxime; Leemans, Alexander

    2015-01-01

    Fiber tractography plays an important role in exploring the architectural organization of fiber trajectories, both in fundamental neuroscience and in clinical applications. With the advent of diffusion MRI (dMRI) approaches that can also model "crossing fibers", the complexity of the fiber network a

  11. Ingegneria degli acquiferi

    CERN Document Server

    Molfetta, Antonio

    2012-01-01

    Il testo fornisce le conoscenze necessarie per affrontare, con un approccio quantitativo, i molteplici aspetti connessi al flusso delle risorse idriche sotterranee (acque di falda) e alla propagazione e bonifica di contaminanti nei sistemi acquiferi. Vengono illustrate le proprietà fondamentali che definiscono la capacità di immagazzinamento, trasporto e rilascio dell’acqua negli acquiferi, e successivamente, descritte le metodiche per la determinazione di tali parametri tramite l’esecuzione e l’interpretazione di prove di falda, di pozzo e di laboratorio. A partire dalla classificazione chimico fisica-tossicologica dei contaminanti vengono, quindi, analizzati i meccanismi di propagazione e illustrate le soluzioni analitiche dell’equazione del trasporto di massa nei mezzi porosi. L’ultima parte del testo è dedicata alla caratterizzazione e bonifica degli acquiferi contaminati. Il testo è rivolto sia agli studenti universitari, sia ai professionisti che debbano affrontare con un approccio quantit...

  12. Friction behaviour of aluminium composites mixed with carbon fibers with different orientations

    Science.gov (United States)

    Caliman, R.

    2016-08-01

    The primary goal of this study work it was to distinguish a mixture of materials with enhanced friction and wearing behaviour. The composite materials may be differentiated from alloys; which can contain two more components but are formed naturally through different processes such as casting. The load applied on the specimen during the tests, is playing a very important role regarding friction coefficient and also the wearing speed. Sintered composites are gaining importance because the reinforcement serves to reduce the coefficient of thermal expansion and increase the strength and modulus. The friction tests are carried out, at the room temperature in dry condition, on a pin-on-disc machine. The exponentially decreasing areas form graphs, represented to the curves coefficient of friction, are attributed to the formation of lubricant transfer film and initial polishing surface samples. The influence of the orientation of the carbon fibers on the friction properties in the sintered polymer composites may be studied by the use of both mechanical wear tests by microscopy and through the use of phenomenological models.

  13. Optimal diffusion MRI acquisition for fiber orientation density estimation: an analytic approach.

    Science.gov (United States)

    White, Nathan S; Dale, Anders M

    2009-11-01

    An important challenge in the design of diffusion MRI experiments is how to optimize statistical efficiency, i.e., the accuracy with which parameters can be estimated from the diffusion data in a given amount of imaging time. In model-based spherical deconvolution analysis, the quantity of interest is the fiber orientation density (FOD). Here, we demonstrate how the spherical harmonics (SH) can be used to form an explicit analytic expression for the efficiency of the minimum variance (maximally efficient) linear unbiased estimator of the FOD. Using this expression, we calculate optimal b-values for maximum FOD estimation efficiency with SH expansion orders of L = 2, 4, 6, and 8 to be approximately b = 1,500, 3,000, 4,600, and 6,200 s/mm(2), respectively. However, the arrangement of diffusion directions and scanner-specific hardware limitations also play a role in determining the realizable efficiency of the FOD estimator that can be achieved in practice. We show how some commonly used methods for selecting diffusion directions are sometimes inefficient, and propose a new method for selecting diffusion directions in MRI based on maximizing the statistical efficiency. We further demonstrate how scanner-specific hardware limitations generally lead to optimal b-values that are slightly lower than the ideal b-values. In summary, the analytic expression for the statistical efficiency of the unbiased FOD estimator provides important insight into the fundamental tradeoff between angular resolution, b-value, and FOD estimation accuracy.

  14. Thermal and Mechanical Buckling Analysis of Hypersonic Aircraft Hat-Stiffened Panels With Varying Face Sheet Geometry and Fiber Orientation

    Science.gov (United States)

    Ko, William L.

    1996-01-01

    Mechanical and thermal buckling behavior of monolithic and metal-matrix composite hat-stiffened panels were investigated. The panels have three types of face-sheet geometry: Flat face sheet, microdented face sheet, and microbulged face sheet. The metal-matrix composite panels have three types of face-sheet layups, each of which is combined with various types of hat composite layups. Finite-element method was used in the eigenvalue extractions for both mechanical and thermal buckling. The thermal buckling analysis required both eigenvalue and material property iterations. Graphical methods of the dual iterations are shown. The mechanical and thermal buckling strengths of the hat-stiffened panels with different face-sheet geometry are compared. It was found that by just microdenting or microbulging of the face sheet, the axial, shear, and thermal buckling strengths of both types of hat-stiffened panels could be enhanced considerably. This effect is more conspicuous for the monolithic panels. For the metal-matrix composite panels, the effect of fiber orientations on the panel buckling strengths was investigated in great detail, and various composite layup combinations offering, high panel buckling strengths are presented. The axial buckling strength of the metal-matrix panel was sensitive to the change of hat fiber orientation. However, the lateral, shear, and thermal buckling strengths were insensitive to the change of hat fiber orientation.

  15. Structural studies of A-form sodium deoxyribonucleic acid: phosphorus-31 nuclear magnetic resonance of oriented fibers.

    Science.gov (United States)

    Nall, B T; Rothwell, W P; Waugh, J S; Rupprecht, A

    1981-03-31

    A highly oriented sample of A-form sodium deoxyribonucleic acid (DNA) has been investigated by using proton-enhanced 31P nuclear magnetic resonance (NMR). Proton-decoupled spectra taken with different angles between the magnetic field direction and the fiber direction are compared to theoretical spectra which are calculated by assuming the following: (1) the orientation of the phosphate groups in the fiber is given by the A-form DNA coordinates suggested by Arnott & Hukins [Arnott, S., & Hukins, D. W. L. (1972) Biochem. Biophys. Res. Commun. 47, 1504-1509]; (2) the DNA phosphate groups may be considered stationary on the NMR time scale; (3) the relevant features of the spectra are determined solely by chemical shift anisotropy of the phosphorus atoms. The experimental and calculated spectra are in excellent agreement and support the validity of the above assumptions contrary to conclusions drawn in another investigation [Shindo, H., Wooton, J. B., Pheiffer, B. H., & Zimmerman, S. B. (1980) Biochemistry 19, 518-526]. In particular, we find no evidence to support the notion of a highly irregular phosphodiester backbone. Comparison of observed and simulated spectra allows the determination of the orientation of the 31P chemical shielding tensor relative to the bonding framework of the phosphodiester group. The orientation agrees with that expected from NMR studies of phosphodiester model compounds [Kohler, S. J., & Klein, M. P. (1976) Biochemistry 15, 967-973; Herzfeld, J., Griffin, R. G., & Haberkorn, R. A. (1978) Biochemistry 17, 2711-2718] and X-ray diffraction of oriented fibers [Arnott, S., & Hukins, D. W. L. (1972) Biochem. Biophys. Res. Commun. 47, 1504-1509].

  16. X-Ray Fiber Diffraction Recordings from Oriented Demembranated Chlamydomonas Flagellar Axonemes.

    Science.gov (United States)

    Toba, Shiori; Iwamoto, Hiroyuki; Kamimura, Shinji; Oiwa, Kazuhiro

    2015-06-16

    The high homology of its axonemal components with humans and a large repertoire of axonemal mutants make Chlamydomonas a useful model system for experiments on the structure and function of eukaryotic cilia and flagella. Using this organism, we explored the spatial arrangement of axonemal components under physiological conditions by small-angle x-ray fiber diffraction. Axonemes were oriented in physiological solution by continuous shear flow and exposed to intense and stable x rays generated in the synchrotron radiation facility SPring-8, BL45XU. We compared diffraction patterns from axonemes isolated from wild-type and mutant strains lacking the whole outer arm (oda1), radial spoke (pf14), central apparatus (pf18), or the α-chain of the outer arm dynein (oda11). Diffraction of the axonemes showed a series of well-defined meridional/layer-line and equatorial reflections. Diffraction patterns from mutant axonemes exhibited a systematic loss/attenuation of meridional/layer-line reflections, making it possible to determine the origin of various reflections. The 1/24 and 1/12 nm(-1) meridional reflections of oda1 and oda11 were much weaker than those of the wild-type, suggesting that the outer dynein arms are the main contributor to these reflections. The weaker 1/32 and 1/13.7 nm(-1) meridional reflections from pf14 compared with the wild-type suggest that these reflections come mainly from the radial spokes. The limited contribution of the central pair apparatus to the diffraction patterns was confirmed by the similarity between the patterns of the wild-type and pf18. The equatorial reflections were complex, but a comparison with electron micrograph-based models allowed the density of each axonemal component to be estimated. Addition of ATP to rigor-state axonemes also resulted in subtle changes in equatorial intensity profiles, which could report nucleotide-dependent structural changes of the dynein arms. The first detailed description of axonemal reflections

  17. Evaluation of Workpiece Temperature during Drilling of GLARE Fiber Metal Laminates Using Infrared Techniques: Effect of Cutting Parameters, Fiber Orientation and Spray Mist Application

    Directory of Open Access Journals (Sweden)

    Khaled Giasin

    2016-07-01

    Full Text Available The rise in cutting temperatures during the machining process can influence the final quality of the machined part. The impact of cutting temperatures is more critical when machining composite-metal stacks and fiber metal laminates due to the stacking nature of those hybrids which subjects the composite to heat from direct contact with metallic part of the stack and the evacuated hot chips. In this paper, the workpiece surface temperature of two grades of fiber metal laminates commercially know as GLARE is investigated. An experimental study was carried out using thermocouples and infrared thermography to determine the emissivity of the upper, lower and side surfaces of GLARE laminates. In addition, infrared thermography was used to determine the maximum temperature of the bottom surface of machined holes during drilling GLARE under dry and minimum quantity lubrication (MQL cooling conditions under different cutting parameters. The results showed that during the machining process, the workpiece surface temperature increased with the increase in feed rate and fiber orientation influenced the developed temperature in the laminate.

  18. The Prevalence of the 22 deg Halo in Cirrus Clouds

    Science.gov (United States)

    Diedenhoven, vanBastiaan

    2014-01-01

    Halos at 22 deg from the sun attributed to randomly-orientated, pristine hexagonal crystals are frequently observed through ice clouds. These frequent sightings of halos formed by pristine crystals pose an apparent inconsistency with the dominance of distorted, nonpristine ice crystals indicated by in situ and remote sensing data. Furthermore, the 46 deg halo, which is associated with pristine hexagonal crystals as well, is observed far less frequently than the 22 deg halo. Considering that plausible mechanisms that could cause crystal distortion such as aggregation, sublimation, riming and collisions are stochastic processes that likely lead to distributions of crystals with varying distortion levels, here the presence of the 22 deg and 46 deg halo features in phase functions of mixtures of pristine and distorted hexagonal ice crystals is examined. We conclude that the 22 deg halo feature is generally present if the contribution by pristine crystals to the total scattering cross section is greater than only about 10% in the case of compact particles or columns, and greater than about 40% for plates. The 46 deg halo feature is present only if the mean distortion level is low and the contribution of pristine crystals to the total scattering cross section is above about 20%, 50% and 70%, in the case of compact crystals, plates and columns, respectively. These results indicate that frequent sightings of 22 deg halos are not inconsistent with the observed dominance of distorted, non-pristine ice crystals. Furthermore, the low mean distortion levels and large contributions by pristine crystals needed to produce the 461 halo features provide a potential explanation of the common sighting of the 22 deg halo without any detectable 46 deg halo.

  19. Collagen fiber orientation in the femoral necks of apes and humans: do their histological structures reflect differences in locomotor loading?

    Science.gov (United States)

    Kalmey, J K; Lovejoy, C O

    2002-08-01

    Human hip joint anatomy differs substantially from that in other primates. Humans modulate pelvic tilt during walking with a highly developed abductor apparatus, but other primates (such as chimpanzees) clearly lack such an apparatus (they exhibit a Trendelenburg gait during bipedal progression). Because the primate femoral neck is cantilevered whenever it supports body mass, it must be consistently subjected to substantial bending at the neck/shaft interface during stance phase in quadrupedal or bipedal locomotion. It has been argued, however, that the powerful abduction during the single support phase in humans results in almost entirely compressive stress on the human femoral neck. We examined collagen fiber orientation in human and chimpanzee femoral neck cortices using circularly polarized light, which has been shown to be a strong correlate of bone loading patterns. Chimpanzee superior femoral neck cortex was shown to be largely nonbirefringent (dark), but the inferior cortex was strongly birefringent. Human femoral necks showed strong birefringence both superiorly and inferiorly. These results are consistent with loading patterns suggested from anatomical structure, and provide corroborative evidence of bone's ability to preferentially orient collagen fibers during extracellular matrix deposition.

  20. On design of fiber-nets and orientation for eigenfrequency optimization of plates

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2006-01-01

    of the discretization and the ratio between the amounts of material put in the two directions of the fiber-net. The optimizations are performed using the finite element method for analysis and the optimization approach is a two-step method. In the first step we first find the best design on the basis of a recursive...

  1. Effect of fiber orientation in uni-directional glass epoxy laminate using acoustic emission monitoring

    Institute of Scientific and Technical Information of China (English)

    V. Arumugam; S. Barath Kumar; C. Santulli; A. Joseph Stanley

    2011-01-01

    Acoustic emission (AE) can be used for in situ structural health monitoring of the composite laminates.One of the main issues of AE is to characterize different damage mechanisms from the detected AE signals.In the present work,pure resin and GFRP composites laminates with different stacking sequences such as 0°,90°,angle ply[±45°],cross-ply [0°/90°] are used to trigger different failure mechanisms when subjected to tensile test with AE monitoring.The study of failure mechanisms is facilitated by the choice of different oriented specimens in which one or two such mechanisms predominate.Range of peak frequencies in each orientation is investigated using FFT analysis.Fast Fourier Transform (FFT) enabled calculating the frequency content of each damage mechanism.Randomly selected hits from each range of peak frequencies for the specimens with different orientations subjected to tensile test with AE monitoring are analyzed using short time FFT (STFFT) analysis.STFFT analysis is used to highlight the possible failure mechanism associated with each signal.The predominance of failure modes in each orientation is useful in the study of discrimination of failure modes in composite laminates from AE data.

  2. Longitudinal enhancement of the hyperechoic regions in ultrasonography of muscles using a Gabor filter bank approach: a preparation for semi-automatic muscle fiber orientation estimation.

    Science.gov (United States)

    Zhou, Yongjin; Zheng, Yong-Ping

    2011-04-01

    In this study, to complement our previously proposed method for estimating muscle fiber orientation, the Gabor filter bank (GF) technique was applied to sonograms of the biceps and forearm muscles to longitudinally enhance the coherently oriented and hyperechoic perimysiums regions. The method involved three steps: orientation field estimation, frequency map computation and Gabor filtering. The method was evaluated using a simulated image distorted with multiplicative speckle noises where the "muscles" were arranged in a bipennate fashion with an "aponeurosis" located in the middle. After enhancement using the GF approach, most of the original hyperechoic bands in the simulated image could be recovered. The proposed method was also tested using a group of biceps and forearm muscle sonograms collected from healthy adult subjects. Compared with the sonograms without enhancement, the enhanced images led to the detection of more linear patterns including muscle fascicles and smaller angle differences compared with the mean of manual results from two operators, therefore, were better prepared for the automatic estimation of muscle fiber orientation. The proposed method has the potential of assisting in the visualization of strongly oriented patterns in skeletal muscle sonograms as well as in the semi-automatic estimation of muscle fiber orientations.

  3. Quantitative assessment on the orientation and distribution of carbon fibers in a conductive polymer composite using high-frequency ultrasound.

    Science.gov (United States)

    Lin, Yi-Hsun; Huang, Chih-Chung; Wang, Shyh-Hau

    2012-05-01

    Conductive polymer composites, typically fabricated from a mix of conductive fillers and a polymer substrate, are commonly applied as bipolar plates in a fuel cell stack. Electrical conductivity is a crucial property that greatly depends on the distribution and orientation of the fillers. In this study, a 50-MHz ultrasound imaging system and analysis techniques capable of nondestructively assessing the properties of carbon fibers (CFs) in conductive polymer composites were developed. Composite materials containing a mix of polycarbonate substrates and 0 to 0.3 wt% of CFs were prepared using an injection molding technique. Ultrasonic A-line signals and C-scan images were acquired from each composite sample in regions at a depth of 0.15 mm beneath the sample surface (region A) and those at a depth of 0.3 mm (region B). The integrated backscatter (IB) and the Nakagami statistical parameter were calculated to quantitatively assess the samples. The area ratio, defined as the percentage of areas composed of CF images normalized by that of the whole C-scan image, was applied to further quantify the orientation of CFs perpendicular to the sample surface. Corresponding to the increase in CF concentrations from 0.1 to 0.3 wt%, the average IB and Nakagami parameter (m) of the composite samples increased from -78.10 ± 2.20 (mean ± standard deviation) to -72.66 ± 1.40 dB and from 0.024 ± 0.012 to 0.048 ± 0.011, respectively. The corresponding area ratios were respectively estimated to be 0.78 ± 0.35%, 2.33 ± 0.66%, and 2.20 ± 0.60% in region A of the samples; those of CFs with a perpendicular orientation were 0.04 ± 0.03%, 0.08 ± 0.02%, and 0.12 ± 0.05%. The area ratios in region B of the samples were calculated to be 1.19 ± 0.54%, 2.81 ± 0.42%, and 2.64 ± 0.76%, and those of CFs with a perpendicular orientation were 0.07 ± 0.04%, 0.12 ± 0.04%, and 0.14 ± 0.03%. According to the results of the orientations and ultrasonic images, CFs tended to distribute more

  4. Methods of determining loads and fiber orientations in anisotropic non-crystalline materials using energy flux deviation

    Science.gov (United States)

    Prosser, William H. (Inventor); Kriz, Ronald D. (Inventor); Fitting, Dale W. (Inventor)

    1993-01-01

    An ultrasonic wave is applied to an anisotropic sample material in an initial direction and an angle of flux deviation of the ultrasonic wave front is measured from this initial direction. This flux deviation angle is induced by the unknown applied load. The flux shift is determined between this flux deviation angle and a previously determined angle of flux deviation of an ultrasonic wave applied to a similar anisotropic reference material under an initial known load condition. This determined flux shift is then compared to a plurality of flux shifts of a similarly tested, similar anisotropic reference material under a plurality of respective, known load conditions, whereby the load applied to the particular anisotropic sample material is determined. A related method is disclosed for determining the fiber orientation from known loads and a determined flux shift.

  5. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts

    Science.gov (United States)

    Ranjkesh, Bahram; Lovschall, Henrik; Erfanparast, Leila; Jafarabadi, Mohammad A; Oskouei, Sina Ghertasi; Isidor, Flemming

    2016-01-01

    ABSTRACT Aim: The aim of this study was to compare the survival of composite resin restorations retained by glass fiber posts or reversed-orientated (upside-down) metal posts in severely decayed primary anterior teeth after 6, 12, and 18 months. Materials and methods: A total of forty-four 3- to 5-year-old children with bilateral severely decayed primary maxillary canines were included. Patients were treated under general anesthesia. After pulpectomy, an intracanal post was seated in the primary maxillary canine on each side: either a glass fiber post or a metallic post in reversed orientation and teeth restored with light-cured composite. Survival rate of each technique was evaluated at predetermined follow-ups and data were analyzed with McNemar’s test (α = 0.05). Results: The difference in survival of restorations retained by two types of posts was not statistically significant in clinical and radiographical evaluations after 6, 12, and 18 months. The survival rate of reversed-orientated metal and glass fiber posts after 18 months was 81.1 and 67.6% respectively (p = 0.14). Conclusion: Reversed-orientated metal post did not show lower clinical survival compared with glass fiber posts in 18-month follow-up. Hence, reversed-orientated metal post can be considered as a potential method to obtain retention for composite restorations in severely decayed primary anterior teeth. How to cite this article: Vafaei A, Ranjkesh B, L0vschall H, Erfanparast L, Jafarabadi MA, Oskouei SG, Isidor F. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts. Int J Clin Pediatr Dent 2016;9(2):109-113. PMID:27365929

  6. Continual Cell Deformation Induced via Attachment to Oriented Fibers Enhances Fibroblast Cell Migration

    OpenAIRE

    Sisi Qin; Vincent Ricotta; Marcia Simon; Clark, Richard A.F.; Rafailovich, Miriam H.

    2015-01-01

    Fibroblast migration is critical to the wound healing process. In vivo, migration occurs on fibrillar substrates, and previous observations have shown that a significant time lag exists before the onset of granulation tissue. We therefore conducted a series of experiments to understand the impact of both fibrillar morphology and migration time. Substrate topography was first shown to have a profound influence. Fibroblasts preferentially attach to fibrillar surfaces, and orient their cytoplasm...

  7. Numerical anlysis of the vacuum infusion process for laminated composites with different fiber orientations.

    OpenAIRE

    Hurtado, Francisco José; Sánchez Kaiser, Antonio; Viedma Robles, Antonio; Díaz, Sebastián

    2015-01-01

    The vacuum infusion (VI) is a process usually applied to manufacture large structures of composite materials, such as wind turbine blades. Present work analyzes the macroscopic resin ow through a laminate of fiberglass plies with different orientations, during the filling stage of the VI process to manufacture two different pieces. The pressure inside the mold, velocity vectors and the resin inlet mass flow are studied through a 3D numerical modeling under non-steady conditions vali...

  8. Characterization of collagen fibers by means of texture analysis of second harmonic generation images using orientation-dependent gray level co-occurrence matrix method.

    Science.gov (United States)

    Hu, Wenyan; Li, Hui; Wang, Chunyou; Gou, Shanmiao; Fu, Ling

    2012-02-01

    Collagen is the most prominent protein in the human body, making up 30% of the total protein content. Quantitative studies have shown structural differences between collagen fibers of the normal and diseased tissues, due to the remodeling of the extracellular matrix during the pathological process. The dominant orientation, which is an important characteristic of collagen fibers, has not been taken into consideration for quantitative collagen analysis. Based on the conventional gray level co-occurrence matrix (GLCM) method, the authors proposed the orientation-dependent GLCM (OD-GLCM) method by estimating the dominant orientation of collagen fibers. The authors validated the utility of the OD-GLCM method on second harmonic generation (SHG) microscopic images of tendons from rats with different ages. Compared with conventional GLCM method, the authors' method has not only improved the discrimination between different tissues but also provided additional texture information of the orderliness of collagen fibers and the fiber size. The OD-GLCM method was further applied to the differentiation of the preliminary SHG images of normal and cancerous human pancreatic tissues. The combination of SHG microscopy and the OD-GLCM method might be helpful for the evaluation of diseases marked with abnormal collagen morphology.

  9. Characterization of collagen fibers by means of texture analysis of second harmonic generation images using orientation-dependent gray level co-occurrence matrix method

    Science.gov (United States)

    Hu, Wenyan; Li, Hui; Wang, Chunyou; Gou, Shanmiao; Fu, Ling

    2012-02-01

    Collagen is the most prominent protein in the human body, making up 30% of the total protein content. Quantitative studies have shown structural differences between collagen fibers of the normal and diseased tissues, due to the remodeling of the extracellular matrix during the pathological process. The dominant orientation, which is an important characteristic of collagen fibers, has not been taken into consideration for quantitative collagen analysis. Based on the conventional gray level co-occurrence matrix (GLCM) method, the authors proposed the orientation-dependent GLCM (OD-GLCM) method by estimating the dominant orientation of collagen fibers. The authors validated the utility of the OD-GLCM method on second harmonic generation (SHG) microscopic images of tendons from rats with different ages. Compared with conventional GLCM method, the authors' method has not only improved the discrimination between different tissues but also provided additional texture information of the orderliness of collagen fibers and the fiber size. The OD-GLCM method was further applied to the differentiation of the preliminary SHG images of normal and cancerous human pancreatic tissues. The combination of SHG microscopy and the OD-GLCM method might be helpful for the evaluation of diseases marked with abnormal collagen morphology.

  10. Time and dose-dependent deformation of SiC/SiC composites With off-axis fiber alignment

    Energy Technology Data Exchange (ETDEWEB)

    Henager, C.H. [Pacific Northwest National Laboratory, Richland WA (United States)

    2007-07-01

    Full text of publication follows: The use of SiC-reinforced composites for fusion reactors or other nuclear applications will not be restricted to 0/90 aligned fiber architecture in all cases. It is important to understand the role of fiber orientation in the strength, toughness, and time-dependent properties for such materials. The use of high-strength ceramic fibers for composites is predicated on optimizing the strength, fracture resistance, and retained strength in aggressive environments, which argues for the best use of fiber strengths, namely on-axis loading for full load transfer to the high-strength fibers. Relatively few researchers have systematically studied the effects of fiber orientation on composite properties, and none have, to the best of our knowledge, performed any time-dependent testing of composites with off-axis fiber orientations. We have performed mechanical property tests on Hi-Nicalon Type-S fiber SiC/SiC composites as a function of fiber orientation. The mechanical testing consisted of 4- point bend strength, 4-point single-edge notched bend fracture toughness, and 4-point bend slow crack growth testing on two composite architectures from ambient to 1600 deg. C (1873 K). The two composite materials that were tested included a {+-}55 deg.-braided-weave composite with Type-S fibers inclined at 55 deg. to the principal composite axes to simulate a tubular-weave architecture and a Type-S 0/90 satin-weave composite as a reference material. A time-dependent fiber-bridging model that accounts for fiber orientation has been developed and its predictions are compared to the strength and crack growth data. The level of agreement suggests that existing models of off-axis bridging fibers are adequate for fusion reactor designs using SiC/SiC composites in off-axis orientations. However, the strength data suggests that off-axis orientations are much weaker than aligned fiber orientations and, thus, care must be taken to ensure that some fraction of

  11. Quantification of Coupled Stiffness and Fiber Orientation Remodeling in Hypertensive Rat Right-Ventricular Myocardium Using 3D Ultrasound Speckle Tracking with Biaxial Testing

    Science.gov (United States)

    Park, Dae Woo; Sebastiani, Andrea; Yap, Choon Hwai; Simon, Marc A.; Kim, Kang

    2016-01-01

    Mechanical and structural changes of right ventricular (RV) in response to pulmonary hypertension (PH) are inadequately understood. While current standard biaxial testing provides information on the mechanical behavior of RV tissues using surface markers, it is unable to fully assess structural and mechanical properties across the full tissue thickness. In this study, the mechanical and structural properties of normotensive and pulmonary hypertension right ventricular (PHRV) myocardium through its full thickness were examined using mechanical testing combined with 3D ultrasound speckle tracking (3D-UST). RV pressure overload was induced in Sprague–Dawley rats by pulmonary artery (PA) banding. The second Piola–Kirchhoff stress tensors and Green-Lagrangian strain tensors were computed in the RV myocardium using the biaxial testing combined with 3D-UST. A previously established non-linear curve-fitting algorithm was applied to fit experimental data to a Strain Energy Function (SEF) for computation of myofiber orientation. The fiber orientations obtained by the biaxial testing with 3D-UST compared well with the fiber orientations computed from the histology. In addition, the re-orientation of myofiber in the right ventricular free wall (RVFW) along longitudinal direction (apex-to-outflow-tract direction) was noticeable in response to PH. For normotensive RVFW samples, the average fiber orientation angles obtained by 3D-UST with biaxial test spiraled from 20° at the endo-cardium to -42° at the epi-cardium (Δ = 62°). For PHRV samples, the average fiber orientation angles obtained by 3D-UST with biaxial test had much less spiral across tissue thickness: 3° at endo-cardium to -7° at epi-cardium (Δ = 10°, P<0.005 compared to normotensive). PMID:27780271

  12. The fabrication of polyaniline/single-walled carbon nanotube fibers containing a highly-oriented filler

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Mi Sun; Shin, Min Kyoon; Ismail, Yahya A; Shin, Su Ryon; Kim, Sun I; Kim, Seon Jeong [Center for Bio-Artificial Muscle and Department of Biomedical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Hyunsook; Lee, Haiwon [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)], E-mail: sjk@hanyang.ac.kr

    2009-02-25

    Highly uniform composite nanofibers composed of well-oriented single-walled carbon nanotubes (SWCNTs) wrapped in a conducting polymer have been fabricated using electrospinning. Water-soluble polyaniline (WS-PANI) was used as a conducting material to improve the processability during electrospinning. The WS-PANI formed a homogeneous dispersion with the SWCNTs and poly(vinyl alcohol), and good compatibility of the WS-PANI with the SWCNTs was demonstrated by data showing interactions between two components and the wrapping of the SWCNTs by the WS-PANI. Through transmission electron microscopy, atomic force microscopy, and polarized Raman spectroscopy, we confirmed that the WS-PANI plays an important role as a conducting polymer matrix to achieve aligned SWCNTs in composite nanofibers and to form uniform nanofibers.

  13. White Matter Changes of Neurite Density and Fiber Orientation Dispersion during Human Brain Maturation.

    Directory of Open Access Journals (Sweden)

    Yi Shin Chang

    Full Text Available Diffusion tensor imaging (DTI studies of human brain development have consistently shown widespread, but nonlinear increases in white matter anisotropy through childhood, adolescence, and into adulthood. However, despite its sensitivity to changes in tissue microstructure, DTI lacks the specificity to disentangle distinct microstructural features of white and gray matter. Neurite orientation dispersion and density imaging (NODDI is a recently proposed multi-compartment biophysical model of brain microstructure that can estimate non-collinear properties of white matter, such as neurite orientation dispersion index (ODI and neurite density index (NDI. In this study, we apply NODDI to 66 healthy controls aged 7-63 years to investigate changes of ODI and NDI with brain maturation, with comparison to standard DTI metrics. Using both region-of-interest and voxel-wise analyses, we find that NDI exhibits striking increases over the studied age range following a logarithmic growth pattern, while ODI rises following an exponential growth pattern. This novel finding is consistent with well-established age-related changes of FA over the lifespan that show growth during childhood and adolescence, plateau during early adulthood, and accelerating decay after the fourth decade of life. Our results suggest that the rise of FA during the first two decades of life is dominated by increasing NDI, while the fall in FA after the fourth decade is driven by the exponential rise of ODI that overcomes the slower increases of NDI. Using partial least squares regression, we further demonstrate that NODDI better predicts chronological age than DTI. Finally, we show excellent test-retest reliability of NODDI metrics, with coefficients of variation below 5% in all measured regions of interest. Our results support the conclusion that NODDI reveals biologically specific characteristics of brain development that are more closely linked to the microstructural features of white

  14. Effect of fiber orientations on surface grinding process of unidirectional C/SiC composites

    Science.gov (United States)

    Zhang, Lifeng; Ren, Chengzu; Ji, Chunhui; Wang, Zhiqiang; Chen, Guang

    2016-03-01

    The machining mechanism of woven ceramic matrix composites is one of the most challenging problems in composite application. To elucidate the grinding mechanism of the woven ceramic matrix composites, a new model material consisting of unidirectional CVI-C/SiC was prepared and ground. The composite was ground in three typical directions and the experimental investigation of the surface grinding process for this composite is described. In addition, the micro structural characteristics and grinding mechanism of the composite were analyzed. The result shows that brittle fracture is the dominant removal mechanism for grinding of the C/SiC composites, and the destroy form of the composites is mainly the syntheses of the matrix cracking, fiber fracture, and interfacial debonding. The grinding force follows the order: Normal > Longitudinal > Transverse, and the surface roughness follows: Longitudinal > Normal > Transverse. The grinding parameters (feed speed, cut depth, grinding speed) have great influence on the grinding force and surface roughness. Based on the findings, the grinding force and surface integrity of the woven ceramic matrix composites can be predicted. Furthermore, it is expected to provide a useful guideline for the design, evaluation and optimal application of the C/SiC composites.

  15. Alignment and articular orientation of lower limbs: manual vs computer-aided measurements on digital radiograms; Allineamento ed orientamento articolare degli arti inferiori: confronto tra misure manuali e computerizzate su radiogrammi digitali

    Energy Technology Data Exchange (ETDEWEB)

    Rozzanigo, Umberto; Caudana, Roberto [Azienda Ospedaliera Carlo Poma, Mantova (Italy). Dipartimento di Diagnostica per Immagini; Pizzoli, Andrea [Azienda Ospedaliera Carlo Poma, Mantova (Italy). Divisione di Ortopedia e Traumatologia; Minari, Chiara [Azienda Ospedaliera Carlo Poma, Mantova (Italy). Servizio di Fisica Sanitaria

    2005-03-01

    Purpose: To compare the manual measurements of lower limbs on digital images with those obtained with dedicated software. Materials and methods: Forty patients with a clinical suspicion of lower limb deformity were enrolled. Eighty digital radiographs were produced with a remote-controlled radiography system (Philips Omnidia-gnost). The measurements were taken separately by an Orthopaedic Surgeon and by a Radiologist, by hand and with the aid of software, respectively. Five parameters were assessed: femoral length, tibial length, distal-medial femoral angle, proximal-medial tibial angle and tibial-femoral angle. The statistical analysis of the comparison was based on Student's-test. The inter-observer variability of the methods, manual and computer-aided, was evaluated with Fisher's F-test on a sample of measurements (20 lower limbs), taken by 5 different Orthopaedic Surgeons and Radiologists, respectively. Results: There were no statistically significant differences between the measurements taken with the manual and computer-aided methods (p>0.05). The overall reproducibility of both methods was similar; conversely, the separate evaluation of angles and lengths showed that the computer-aided method was less variable in the measurements of lengths than the manual method. Conclusions: The computer-aided evaluation of the alignment and articular orientation parameters of lower limbs is as accurate and reliable as the traditional manual method, but is faster and allows better-quality images.

  16. Measurements of fiber orientation in two-dimensional fiber suspension flow using image-processing method; Gazo shoriho ni yoru sen`i gan`yutai no nijigen nagare ni okeru sen`i haiko no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Chono, S.; Tanoue, S.; Iemoto, Y. [Fukui University, Fukui (Japan). Faculty of Engineering

    1998-10-25

    Orientation profiles of fibers in fiber suspension flow between two parallel plates with a square cylinder on the center axis was studied by using the computer image analysis. The orientational order parameter S decreases near the square cylinder because the flow changes its direction and also a wake is developed, while it is large near the channel wall owing to high shear deformation. The preferred angle and S decrease in the downstream vicinity of the square cylinder, and reach fully-developed values at a farther area. S along the channel center axis increases with increasing a fiber concentration and the Reynolds number. The size of a square cylinder has an effect on the fiber orientation near the cylinder. Since a stagnation region and a large wake are developed before and after a cylinder for a viscoelastic fluid, a lower value of S near the cylinder is obtained for the viscoelastic fluid compared to that for a Newtonian fluid. At a downstream area, however, the viscoelastic fluid gives a higher values of S. 21 refs., 14 figs., 1 tab.

  17. Cloning and sequencing the degS-degU operon from an alkalophilic Bacillus-brevis

    CSIR Research Space (South Africa)

    Louw, M

    1994-10-01

    Full Text Available at the amino acid level to the B. subtilis degS-degU genes showed 74% and 84% similarity, respectively. On a multicopy vector the B. brevis degS-degU genes were found to cause hypersecretion of several extracellular enzymes in a B. subtilis rec (-) strain...

  18. Electrospun meshes possessing region-wise differences in fiber orientation, diameter, chemistry and mechanical properties for engineering bone-ligament-bone tissues.

    Science.gov (United States)

    Samavedi, Satyavrata; Vaidya, Prasad; Gaddam, Prudhvidhar; Whittington, Abby R; Goldstein, Aaron S

    2014-12-01

    Although bone-patellar tendon-bone (B-PT-B) autografts are the gold standard for repair of anterior cruciate ligament ruptures, they suffer from drawbacks such as donor site morbidity and limited supply. Engineered tissues modeled after B-PT-B autografts are promising alternatives because they have the potential to regenerate connective tissue and facilitate osseointegration. Towards the long-term goal of regenerating ligaments and their bony insertions, the objective of this study was to construct 2D meshes and 3D cylindrical composite scaffolds - possessing simultaneous region-wise differences in fiber orientation, diameter, chemistry and mechanical properties - by electrospinning two different polymers from off-set spinnerets. Using a dual drum collector, 2D meshes consisting of an aligned polycaprolactone (PCL) fiber region, randomly oriented poly(lactide-co-glycolide) (PLGA) fiber region and a transition region (comprised of both PCL and PLGA fibers) were prepared, and region-wise differences were confirmed by microscopy and tensile testing. Bone marrow stromal cells (BMSCs) cultured on these meshes exhibited random orientations and low aspect ratios on the random PLGA regions, and high aspect ratios and alignment on the aligned PCL regions. Next, meshes containing an aligned PCL region flanked by two transition regions and two randomly oriented PLGA regions were prepared and processed into 3D cylindrical composite scaffolds using an interpenetrating photo-crosslinkable polyethylene glycol diacrylate hydrogel to recapitulate the shape of B-PT-B autografts. Tensile testing indicated that cylindrical composites were mechanically robust, and eventually failed due to stress concentration in the aligned PCL region. In summary, this study demonstrates a process to fabricate electrospun meshes possessing region-wise differences in properties that can elicit region-dependent cell responses, and be readily processed into scaffolds with the shape of B-PT-B autografts.

  19. Oriented functionalization of natural hollow kapok fiber for highly efficient removal of toxic Hg(II from aqueous solution

    Directory of Open Access Journals (Sweden)

    Feng eWang

    2016-02-01

    Full Text Available Due to hollow and tubular structure, a natural kapok fiber (KF was used as the support and orientation matrix to control the polymerization of ethyleneglycol dimethacrylate (EGDMA and N-vinylimidazole (VIM along its inherent axial surface via a facile in situ rapid polymerization reaction in air atmosphere. The as-formed KF@VIM/EGDMA composite is featured with porous surface and rich N-containing functional groups for potential application as a highly efficient adsorbent for removal of toxic Hg(II from aqueous solution. The variables affecting the adsorption capacity were studied, including monomer ratio, external pH values, contact time, and initial Hg(II concentration. The pseudo-second-order equation and two adsorption isotherms including Langmuir and Freundlich equations were applied to determine the adsorption kinetics and adsorption capacity. The results show that the as-prepared KF@VIM/EGDMA composite has a maximum adsorption capacity of 697 mg/g to Hg(II, while no appreciable adsorption capacity can be found for KF itself. Given its intrinsic large lumen, faster adsorption kinetics (45 min are also expected and observed for KF@VIM/EGDMA. After a simple filtration, this adsorbent can be directly separated from the aqueous solution and then be regenerated for multi-cyclable utilization. During the adsorption process, the chemical complexing represents the main adsorption mechanism. As a naturally renewable KF, such a simple preparation method opens a new avenue to develop highly efficient and economically viable adsorbent for removal of toxic heavy metal from aqueous solution.

  20. Fisica degli atomi e dei nuclei

    CERN Document Server

    Bernardini, Carlo

    1965-01-01

    Evidenza della struttura atomica della materia ; le proprietà degli atomi e la meccanica atomica ; gli atomi e le radiazioni elettromagnetiche ; struttura microscopica dello stato gassoso ; struttura microscopica dello stato liquido ; struttura microscopica della stato solido ; proprietà elettriche e magnetiche delle sostanze ; proprietà dei nuclei degli atomi ; le particelle elementari.

  1. Fiber diffraction without fibers.

    Science.gov (United States)

    Poon, H-C; Schwander, P; Uddin, M; Saldin, D K

    2013-06-28

    Postprocessing of diffraction patterns of completely randomly oriented helical particles, as measured, for example, in so-called "diffract-and-destroy" experiments with an x-ray free electron laser can yield "fiber diffraction" patterns expected of fibrous bundles of the particles. This will allow "single-axis alignment" to be performed computationally, thus obviating the need to do this by experimental means such as forming fibers and laser or flow alignment. The structure of such particles may then be found by either iterative phasing methods or standard methods of fiber diffraction.

  2. Orientation During Initial Learning and Subsequent Discrimination of Faces

    Science.gov (United States)

    Cohen, Malcolm M.; Holton, Emily M. (Technical Monitor)

    1997-01-01

    Discrimination of facial features degrades with stimulus rotation (e.g., the "Margaret Thatcher" effect). Thirty-two observers learned to discriminate between two upright, or two inverted, faces. Images, erect and rotated by +/-45deg, +/-90deg, +/-135deg and 180deg about the line of sight, were presented on a computer screen. Initial discriminative reaction times increased with stimulus rotation only for observers who learned the upright faces. Orientation during learning is critical in identifying faces subsequently seen at different orientations.

  3. Single molecule fluorescence image patterns linked to dipole orientation and axial position: application to myosin cross-bridges in muscle fibers.

    Directory of Open Access Journals (Sweden)

    Thomas P Burghardt

    Full Text Available BACKGROUND: Photoactivatable fluorescent probes developed specifically for single molecule detection extend advantages of single molecule imaging to high probe density regions of cells and tissues. They perform in the native biomolecule environment and have been used to detect both probe position and orientation. METHODS AND FINDINGS: Fluorescence emission from a single photoactivated probe captured in an oil immersion, high numerical aperture objective, produces a spatial pattern on the detector that is a linear combination of 6 independent and distinct spatial basis patterns with weighting coefficients specifying emission dipole orientation. Basis patterns are tabulated for single photoactivated probes labeling myosin cross-bridges in a permeabilized muscle fiber undergoing total internal reflection illumination. Emitter proximity to the glass/aqueous interface at the coverslip implies the dipole near-field and dipole power normalization are significant affecters of the basis patterns. Other characteristics of the basis patterns are contributed by field polarization rotation with transmission through the microscope optics and refraction by the filter set. Pattern recognition utilized the generalized linear model, maximum likelihood fitting, for Poisson distributed uncertainties. This fitting method is more appropriate for treating low signal level photon counting data than χ(2 minimization. CONCLUSIONS: Results indicate that emission dipole orientation is measurable from the intensity image except for the ambiguity under dipole inversion. The advantage over an alternative method comparing two measured polarized emission intensities using an analyzing polarizer is that information in the intensity spatial distribution provides more constraints on fitted parameters and a single image provides all the information needed. Axial distance dependence in the emission pattern is also exploited to measure relative probe position near focus. Single

  4. Compensated-power differential calorimeter -196 deg. C/400 deg. C; Calorimetre differentiel a puissance compensee -196 deg. C/400 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Bonjour, E.; Pierre, J.; Agagliate, S.; Bertrand, P.; Faivre, J.; Lagnier, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires, Section physico-chimie et basses temperatures

    1967-06-01

    A differential calorimetric device of original design is described. Its allows direct measurements of thermal effects (adsorption or release) during a linear rise of temperature. The self compensated power method which is applied by means of a very sensitive control system, gives a direct value of the different heat capacity between the sample and a dummy of it. The detection threshold is about {+-} 100 micro-watts to {+-} 250 micro-watts. Applications: - Generally measurements of enthalpy changes of massive or powdered samples. - Measurement of Wigner energy after low temperature irradiation (77 deg. K). - Measurements of energy release in low temperature (77 deg. K) cold worked metals. (authors) [French] On decrit un dispositif de calorimetrie differentielle, de conception originale, qui permet de mesurer directement des effets thermiques en absorption ou en degagement de chaleur, au cours d'une montee en temperature lineaire. La methode de compensation automatique de puissance qui est mise en oeuvre au moyen de cha es d'asservissement tres sensibles, conduit a une determination directe de la capacite calorifique differencielle entre l'echantillon et sa reference. Le seuil de detection est de l'ordre de {+-} 100 a {+-} 250 microwatts. Applications: - D'une facon generale, mesure des variations enthalpiques, sur echantillons massifs ou en poudre. - Mesure de l'energie Wigner apres irradiation a basse temperature (77 deg. K). - Mesure de l'energie restauree apres deformation des metaux a basse temperature (77 deg. K). (auteurs)

  5. Testimonianze di vittime degli anni di piombo

    DEFF Research Database (Denmark)

    Cecchini, Leonardo

    Testimonianze di vittime degli anni di piombo In un articolo pubblicato nel 2008 sulla webzine Nazione indiana Christian Raimo criticava quello che poi Giovanni De Luna qualche anno dopo nel suo libro La Repubblica del dolore (2011) ha chiamato “paradigma vittimario”; cioè la presenza predominante...

  6. Femtosecond laser fabrication of long period fiber gratings by a transversal-scanning inscription method and the research of its orientational bending characteristics

    Science.gov (United States)

    Dong, Xin-Ran; Sun, Xiao-Yan; Li, Hai-Tao; Hu, You-Wang; Duan, Ji-An; Zhou, Jian-Ying; Wang, Cong

    2015-08-01

    In order to make the whole fiber core modified, an improved point-by-point inscription method (called a transversal-scanning inscription method) is proposed to fabricate long period fiber gratings (LPFGs) by using femtosecond laser. LPFGs with an attenuation depth of 16 dB are achieved within the wavelength range of 1580-1680 nm. We have compared the bending properties of LPFGs fabricated by the line-by-line scanning inscription method and the transversal-scanning inscription method at the orthogonal directions. It is found that increasing scanning area using the transversal-scanning method can enhance the bend sensitivity obviously. The resulting curvature sensitivities are -4.82 nm/m-1 and -1.63 nm/m-1 at the 0° and 90° bend orientations respectively, within the curvature range from 1.75 m-1 to 3 m-1 in the experiment. The LPFG-I fabricated by the line-by-line scanning inscription method experiences red-shift, while the LPFG-II fabricated by the transversal-scanning inscription method experiences blue-shift.

  7. A parametric study of variables that affect fiber microbuckling initiation in composite laminates. I - Analyses. II - Experiments

    Science.gov (United States)

    Guynn, E. G.; Ochoa, Ozden O.; Bradley, Walter L.

    1992-01-01

    The effects of the stacking sequence (orientation of plies adjacent to the 0-deg plies), free surfaces, fiber/matrix interfacial bond strength, initial fiber waviness, resin-rich regions, and nonlinear shear constitutive behavior of the resin on the initiation of fiber microbuckling in thermoplastic composites were investigated using nonlinear geometric and nonlinear 2D finite-element analyses. Results show that reductions in the resin shear tangent modulus, large amplitudes of the initial fiber waviness, and debonds each cause increases in the localized matrix shear strains; these increases lead in turn to premature initiation of fiber microbuckling. The numerical results are compared to experimental data obtained using three thermoplastic composite material systems: (1) commercial APC-2, (2) QUADRAX Unidirectional Interlaced Tape, and AU4U/PEEK.

  8. Comparison of PCBBs and CTs irradiated at 250 deg. C, 300 deg. C, and 350 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Rensman, J.; Nolles, H.N. [ECN-Energy Research Foundation, Research Unit NRG, Westerduinweg, Petten (Netherlands); Lucon, E. [SCK-CEN, Institute of Nuclear Material Science, Boeretang, Mol (Belgium); Spatig, P. [EPFL-CRDP, Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH Villigen PSI (Switzerland)

    2007-07-01

    Full text of publication follows: The fracture toughness of irradiated Eurofer steel is difficult to characterise. Several limitations are identified in this paper with respect to the conventional treatment of fracture data of BCC steels in the transition region. It is uncertain that the RPV Master Curve is applicable to unirradiated Eurofer, and low temperature irradiation adds more to this uncertainty. The lack of strain hardening and the dose variation within each batch are two complicating factors. An irradiation has been carried out in the BFR up to a nominal dose of 2.5 dpa at 250 deg. C, 300 deg. C, and 350 deg. C in sodium. Twelve small size pre-cracked bend specimens and eight mini-CT specimens have been irradiated in each temperature section. We analyse the effect of constraint and censoring limit, and the specimen geometry and loading configuration. The fracture data are treated in several ways that are proposed in open literature to investigate the effect of irradiation on a reference temperature like the ASTM E1921 T0. In addition, the relation between the tensile hardening, which is presented in a companion paper, and the shift calculated with the various methods is studied. (authors)

  9. Bacillus subtilis Two-Component System Sensory Kinase DegS Is Regulated by Serine Phosphorylation in Its Input Domain

    Science.gov (United States)

    Jers, Carsten; Kobir, Ahasanul; Søndergaard, Elsebeth Oline; Jensen, Peter Ruhdal; Mijakovic, Ivan

    2011-01-01

    Bacillus subtilis two-component system DegS/U is well known for the complexity of its regulation. The cytosolic sensory kinase DegS does not receive a single predominant input signal like most two-component kinases, instead it integrates a wide array of metabolic inputs that modulate its activity. The phosphorylation state of the response regulator DegU also does not confer a straightforward “on/off” response; it is fine-tuned and at different levels triggers different sub-regulons. Here we describe serine phosphorylation of the DegS sensing domain, which stimulates its kinase activity. We demonstrate that DegS phosphorylation can be carried out by at least two B. subtilis Hanks-type kinases in vitro, and this stimulates the phosphate transfer towards DegU. The consequences of this process were studied in vivo, using phosphomimetic (Ser76Asp) and non-phosphorylatable (Ser76Ala) mutants of DegS. In a number of physiological assays focused on different processes regulated by DegU, DegS S76D phosphomimetic mutant behaved like a strain with intermediate levels of DegU phosphorylation, whereas DegS S76A behaved like a strain with lower levels of DegU phophorylation. These findings suggest a link between DegS phosphorylation at serine 76 and the level of DegU phosphorylation, establishing this post-translational modification as an additional trigger for this two-component system. PMID:21304896

  10. Bacillus subtilis two-component system sensory kinase DegS is regulated by serine phosphorylation in its input domain.

    Directory of Open Access Journals (Sweden)

    Carsten Jers

    Full Text Available Bacillus subtilis two-component system DegS/U is well known for the complexity of its regulation. The cytosolic sensory kinase DegS does not receive a single predominant input signal like most two-component kinases, instead it integrates a wide array of metabolic inputs that modulate its activity. The phosphorylation state of the response regulator DegU also does not confer a straightforward "on/off" response; it is fine-tuned and at different levels triggers different sub-regulons. Here we describe serine phosphorylation of the DegS sensing domain, which stimulates its kinase activity. We demonstrate that DegS phosphorylation can be carried out by at least two B. subtilis Hanks-type kinases in vitro, and this stimulates the phosphate transfer towards DegU. The consequences of this process were studied in vivo, using phosphomimetic (Ser76Asp and non-phosphorylatable (Ser76Ala mutants of DegS. In a number of physiological assays focused on different processes regulated by DegU, DegS S76D phosphomimetic mutant behaved like a strain with intermediate levels of DegU phosphorylation, whereas DegS S76A behaved like a strain with lower levels of DegU phophorylation. These findings suggest a link between DegS phosphorylation at serine 76 and the level of DegU phosphorylation, establishing this post-translational modification as an additional trigger for this two-component system.

  11. A helical scintillating fiber hodoscope

    CERN Document Server

    Altmeier, M; Bisplinghoff, J; Bissel, T; Bollmann, R; Busch, M; Büsser, K; Colberg, T; Demiroers, L; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross, A; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jeske, M; Jonas, E; Krause, H; Lahr, U; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuck, T; Meinerzhagen, A; Naehle, O; Pfuff, M; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Sanz, B; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Thomas, S; Trelle, H J; Weise, E; Wellinghausen, A; Wiedmann, W; Woller, K; Ziegler, R

    1999-01-01

    A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9 deg. <= THETA<=72 deg. and 0 deg. <=phi (cursive,open) Greek<=360 deg. in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes. (author)

  12. A helical scintillating fiber hodoscope

    Energy Technology Data Exchange (ETDEWEB)

    Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Bissel, T.; Bollmann, R.; Busch, M.; Buesser, K.; Colberg, T.; Demiroers, L.; Diehl, O.; Dohrmann, F.; Engelhardt, H.P.; Eversheim, P.D.; Felden, O.; Gebel, R.; Glende, M.; Greiff, J.; Gross, A.; Gross-Hardt, R.; Hinterberger, F.; Jahn, R.; Jeske, M.; Jonas, E.; Krause, H.; Lahr, U.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuck, T.; Meinerzhagen, A.; Naehle, O.; Pfuff, M.; Prasuhn, D.; Rohdjess, H.; Rosendaal, D.; Rossen, P. von; Sanz, B.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Thomas, S.; Trelle, H.J.; Weise, E.; Wellinghausen, A.; Wiedmann, W.; Woller, K.; Ziegler, R

    1999-07-21

    A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9 deg. {<=}{theta}{<=}72 deg. and 0 deg. {<=}phi (cursive,open) Greek{<=}360 deg. in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes. (author)

  13. Global map of lithosphere thermal thickness on a 1 deg x 1 deg grid - digitally available

    DEFF Research Database (Denmark)

    Artemieva, Irina

    2014-01-01

    than 250 km) lithosphere is restrictedsolely to young Archean terranes (3.0–2.6 Ga), while in old Archean cratons (3.6–3.0 Ga) lithospheric roots donot extend deeper than 200–220 km.The TC1 model is presented by a set of maps, which show significant thermal heterogeneity within continentalupper mantle......This presentation reports a 1 deg 1 deg global thermal model for the continental lithosphere (TC1). The modelis digitally available from the author’s web-site: www.lithosphere.info.Geotherms for continental terranes of different ages (early Archean to present) are constrained by reliabledata...

  14. Bacillus subtilis Two-Component System Sensory Kinase DegS Is Regulated by Serine Phosphorylation in Its Input Domain

    DEFF Research Database (Denmark)

    Jers, Carsten; Kobir, Ahasanul; Søndergaard, Elsebeth Oline;

    2011-01-01

    Bacillus subtilis two-component system DegS/U is well known for the complexity of its regulation. The cytosolic sensory kinase DegS does not receive a single predominant input signal like most two-component kinases, instead it integrates a wide array of metabolic inputs that modulate its activity...

  15. Angiopatia diabetica e amputazione degli arti inferiori: valutazioni preliminari degli episodi di ricovero ripetuti

    Directory of Open Access Journals (Sweden)

    P. Trerotoli

    2003-05-01

    Full Text Available

    Obiettivi: l’obiettivo principale dello studio è stata la valutazione dei ricoveri ripetuti nei soggetti con vasculopatia diabetica, rispetto ai soggetti con vasculopatia non diabetica.

    Materiali e Metodi: sono state selezionate le SDO del triennio 1998-2000 contenenti, in uno dei campi di diagnosi, i codici di diabete mellito, con e senza complicanze (codici ICD9 ed ICD9CM, 250.—, vasculopatia periferica (440.2 e 440.8, ulcera periferica (707.1, 707.8, 707.9, gangrena (785.4. Le SDO con diagnosi di vasculopatia diabetica sono state considerate come angiopatie diabetiche (AD; le altre sono state attribuite agli angiopatici non diabetici (AND. Le SDO con diabete non complicato e arteriopatia periferica sono state eliminate. L’intervento di amputazione è stato individuato dalla presenza del codice ICD9CM di procedura 84.—. La ripetitività degli episodi è stata valutata usando il codice fiscale come identificativo del paziente. Risultati: sono state rilevate 5814 dimissioni di AD e 9010 di AND. Le amputazioni sono state 285 (4,90% negli AD e 485 (5,38% negli AND. I ricoveri ripetuti sono stati 13 negli AD e 12 negli AND. Le amputazioni sono state osservate verso il 4°-5° episodio di ricovero negli AD, mentre già dal 2° episodio negli AND. Le ulcere erano presenti nel 36,05% (il 36,5% nel primo episodio di ricovero, che resta costante negli episodi successivi degli AND e nel 10,97% degli AD (9,84% nel primo episodio, con un incremento fino al 20% del 5° episodio. Un episodio in day-hospital (DH si osserva nel 12,32% degli AD, contro il 4,20% degli AND.

    Conclusioni: l’accesso degli AD all’assistenza intraospedaliera avviene più frequentemente in DH, i passi successivi sono caratterizzati dalla comparsa dell’ulcera o gangrena e infine dall’amputazione. Nel gruppo degli AD è stato osservato un eccesso di ospedalizzazione, probabilmente per ripetitività del

  16. Influence of thermomechanical processing on shear bands formation and magnetic properties of a 3% Si non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Silva Ferreira de Dafe, Sara, E-mail: saradafe@gmail.com [Physics Department, Federal University of Ouro Preto, Campus Universitario, Ouro Preto, MG 35400000 (Brazil); Costa Paolinelli, Sebastiao da [Research Department, ArcelorMittal Inox Brasil, Praca Primeiro de Maio, 9 Timoteo, MG 35180018 (Brazil); Barros Cota, Andre [Physics Department, Federal University of Ouro Preto, Campus Universitario, Ouro Preto, MG 35400000 (Brazil)

    2011-12-15

    The effect of thermomechanical processing on the formation of shear bands and on the magnetic properties of a 3.0 wt% silicon non-oriented steel was investigated by hot rolling samples with different thicknesses at different temperatures, in order to obtain a variation in hot band grain size and cold strain. All the samples were processed in a single-stage cold rolling and finally annealed at 1020 deg. C. It was found that the increase of the hot band grain size decreases the {gamma} fiber volume fraction and increases the {eta} fiber volume fraction after the final annealing. The increase of the cold strain strongly contributed to this result. A good combination of intense generation of shear bands, and proper crystallographic texture, due to higher nucleation of grains with favorable orientations to magnetization in these bands, can be obtained for the samples hot rolled at 1000 and 1120 deg. C and submitted to cold strain of 64.3% and 72.2% respectively. However the best combination of B{sub 50}, W{sub 15/60} and {mu}{sub r} can be obtained by hot rolling the samples at 1000 deg. C to the thickness of 1.4 mm, corresponding to 64.3% of cold strain. - Highlights: > Effect of processing on the magnetic properties of a non-oriented electrical steel. > Shear band generation during cold rolling is essential to reach a favorable texture. > Great magnetic properties obtained by hot rolling at 1000 deg. C and 64.3% cold strain.

  17. Global map of lithosphere thermal thickness on a 1 deg x 1 deg grid - digitally available

    Science.gov (United States)

    Artemieva, Irina

    2014-05-01

    This presentation reports a 1 deg ×1 deg global thermal model for the continental lithosphere (TC1). The model is digitally available from the author's web-site: www.lithosphere.info. Geotherms for continental terranes of different ages (early Archean to present) are constrained by reliable data on borehole heat flow measurements (Artemieva and Mooney, 2001), checked with the original publications for data quality, and corrected for paleo-temperature effects where needed. These data are supplemented by cratonic geotherms based on xenolith data. Since heat flow measurements cover not more than half of the continents, the remaining areas (ca. 60% of the continents) are filled by the statistical numbers derived from the thermal model constrained by borehole data. Continental geotherms are statistically analyzed as a function of age and are used to estimate lithospheric temperatures in continental regions with no or low quality heat flow data. This analysis requires knowledge of lithosphere age globally. A compilation of tectono-thermal ages of lithospheric terranes on a 1 deg × 1 deg grid forms the basis for the statistical analysis. It shows that, statistically, lithospheric thermal thickness z (in km) depends on tectono-thermal age t (in Ma) as: z=0.04t+93.6. This relationship formed the basis for a global thermal model of the continental lithosphere (TC1). Statistical analysis of continental geotherms also reveals that this relationship holds for the Archean cratons in general, but not in detail. Particularly, thick (more than 250 km) lithosphere is restricted solely to young Archean terranes (3.0-2.6 Ga), while in old Archean cratons (3.6-3.0 Ga) lithospheric roots do not extend deeper than 200-220 km. The TC1 model is presented by a set of maps, which show significant thermal heterogeneity within continental upper mantle. The strongest lateral temperature variations (as large as 800 deg C) are typical of the shallow mantle (depth less than 100 km). A map of the

  18. Global map of lithosphere thermal thickness on a 1 deg x 1 deg grid - digitally available

    DEFF Research Database (Denmark)

    Artemieva, Irina

    2014-01-01

    than 250 km) lithosphere is restrictedsolely to young Archean terranes (3.0–2.6 Ga), while in old Archean cratons (3.6–3.0 Ga) lithospheric roots donot extend deeper than 200–220 km.The TC1 model is presented by a set of maps, which show significant thermal heterogeneity within continentalupper mantle......This presentation reports a 1 deg 1 deg global thermal model for the continental lithosphere (TC1). The modelis digitally available from the author’s web-site: www.lithosphere.info.Geotherms for continental terranes of different ages (early Archean to present) are constrained by reliabledata...... of the continents, the remaining areas (ca. 60% ofthe continents) are filled by the statistical numbers derived from the thermal model constrained by boreholedata. Continental geotherms are statistically analyzed as a function of age and are used to estimate lithospherictemperatures in continental regions...

  19. OMP Peptides Activate the DegS Stress-Sensor Protease by a Relief of Inhibition Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Jungsan; Grant, Robert A.; Sauer, Robert T.; MIT

    2010-03-19

    In the E. coli periplasm, C-terminal peptides of misfolded outer-membrane porins (OMPs) bind to the PDZ domains of the trimeric DegS protease, triggering cleavage of a transmembrane regulator and transcriptional activation of stress genes. We show that an active-site DegS mutation partially bypasses the requirement for peptide activation and acts synergistically with mutations that disrupt contacts between the protease and PDZ domains. Biochemical results support an allosteric model, in which these mutations, active-site modification, and peptide/substrate binding act in concert to stabilize proteolytically active DegS. Cocrystal structures of DegS in complex with different OMP peptides reveal activation of the protease domain with varied conformations of the PDZ domain and without specific contacts from the bound OMP peptide. Taken together, these results indicate that the binding of OMP peptides activates proteolysis principally by relieving inhibitory contacts between the PDZ domain and the protease domain of DegS.

  20. La poesia sabiana degli Anni Venti

    Directory of Open Access Journals (Sweden)

    Atilij Rakar

    1975-11-01

    Full Text Available Muovendo da un confronto fra il Saba del primo Canzoniere e le Figure e canti coi quali l'opera del poeta triestino continua negli anni venti, l'autore cerca di individuare i caratteri che meglio definiscono la poesia sabiana di questo secondo periodo. Messi in evidenza alcuni temi su cui verte il discorso sabiano fin delle Poesie dell'adolescenza e giovanili, le opere degli anni venti si rivelano come esiti di un poliforme compendio in cui il poeta vuol chiarire il senso del cammino percorso e comp:tendere quelle che sono le ragioni prime del suo poetare. Si manifestano qui, anche in maniera esplicita, alcuni motivi fondamentali del Canzionere: basti pensare, ad esempio, a Il borgo che offre la chiave per l'interprezazione di tutto un filone della tematica sabiana, o alle Fughe, con le quali il poeta vuol esprimere l'essenza del proprio sentire. La poetica delle »figure« e dei »canti« composti negli anni venti, non segnerebbe dunque una conversione di Saba ai »miti della forma«, come inducono a credere anche certe apostrofi del poeta stesso, rna può esser definita solo se vista in funzione dei contenuti che determinano il suo formarsi.

  1. Spin Interference in Rashba 2DEG Systems

    Science.gov (United States)

    Nitta, Junsaku

    The gate controllable SOI provides useful information about spin interference.1 Spin interference effects are studied in two different interference loop structures. It is known that sample specific conductance fluctuations affect the conductance in the interference loop. By using array of many interference loops, we carefully pick up TRS Altshuler-Aronov-Spivak (AAS)-type oscillation which is not sample specific and depends on the spin phase. The experimentally obtained gate voltage dependence of AAS oscillations indicates that the spin precession angle can be controlled by the gate voltage.2 We demonstrate the time reversal Aharonov-Casher (AC) effect in small arrays of mesoscopic rings.3 By using an electrostatic gate we can control the spin precession angle rate and follow the AC phase over several interference periods. We also see the second harmonic of the AC interference, oscillating with half the period. The spin interference is still visible after more than 20π precession angle. We have proposed a Stern-Gerlach type spin filter based on the Rashba SOI.4 A spatial gradient of effective magnetic field due to the nonuniform SOI separates spin up and down electrons. This spin filter works even without any external magnetic fields and ferromagnetic contacts. We show the semiconductor/ferromagnet hybrid structure is an effective way to detect magnetization process of submicron magnets. The problem of the spin injection from ferromagnetic contact into 2DEG is also disicussed. Note from Publisher: This article contains the abstract only.

  2. Evaluation of reconstruction arc in myocardial SPECT imaging using a cardiac phantom. Comparison between 360deg and 180deg arcs

    Energy Technology Data Exchange (ETDEWEB)

    Kashikura, Kenichi [Japan Science and Technology Corp., Tokyo (Japan); Kashikura, Akemi; Terada, Shinichirou; Kobayashi, Hideki

    1996-10-01

    In order to investigate the effect of reconstruction arc on myocardial SPECT images, a series of phantom studies was performed with and without plastic chambers simulating perfusion defects using {sup 201}Tl and {sup 99m}Tc. Coefficient of variations (CV) of the counts among the ROIs and defect contrast were evaluated in 360deg and 180deg images reconstructed from the same 360deg projection data. Reconstruction processes were identical for all images. In the absence of defects, the CV of the counts were approximately the same in 360deg and 180deg images. The CV of the counts in the 360deg {sup 201}Tl image, among 4 defects located on the anterior, lateral, inferoposterior, and septal walls, was superior to those in the 180deg images. In contrast, in the {sup 99m}Tc images, the CV of the counts among the 4 defects in the 180deg image was superior to those of the 360deg image. The defect contrast was changed both by the location of the defect and by the reconstruction arc ({sup 201}Tl, {sup 99m}Tc). The defect contrast of the 180deg images, in both {sup 201}Tl and {sup 99m}Tc experiments, was closer to the true contrast value as calculated by the count ratio between myocardium and defect. Although the defect contrast in the anterior, lateral and septal walls was more emphasized in the 180deg images, the defect contrast in the inferoposterior wall was less emphasized in the 180deg images compared to the 360deg ({sup 201}Tl, {sup 99m}Tc). (author)

  3. Fiber Optic Temperature Sensor Based on Multimode Interference Effects

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Soto, J G; Antonio-Lopez, J E; Sanchez-Mondragon, J J [Photonics and Optical Physics Laboratory, Optics Department, INAOE Apdo. Postal 51 and 216, Tonantzintla, Puebla 72000 (Mexico); May-Arrioja, D A, E-mail: darrioja@uat.edu.mx

    2011-01-01

    A novel fiber optic temperature sensor based on multimode interference was designed, fabricated and tested. The sensor is very simple and inexpensive since we only need to splice a section of multimode fiber between two single mode fibers. Using this device a sensing range of 25 deg. C to 375 deg. C is demonstrated. We should also highlight that due to the pass-band filter response of MMI devices, multiplexing is rather simple by just changing the length of the multimode section.

  4. The structures of Arabidopsis Deg5 and Deg8 reveal new insights into HtrA proteases

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China); University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China); Gao, Feng [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China); Fan, Haitian; Shan, Xiaoyue [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China); University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China); Sun, Renhua [Chinese Academy of Sciences, 20 Nanxincun, Haidian District, Beijing 100093 (China); University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China); Liu, Lin, E-mail: liulin@ibcas.ac.cn [Chinese Academy of Sciences, 20 Nanxincun, Haidian District, Beijing 100093 (China); Gong, Weimin, E-mail: liulin@ibcas.ac.cn [Chinese Academy of Sciences, 5 Datun Road, Chaoyang District, Beijing 100101 (China)

    2013-05-01

    The crystal structures of Arabidopsis Deg5 and Deg8 have been determined to resolutions of 2.6 and 2.0 Å, respectively, revealing novel structural features of HtrA proteases. Plant Deg5 and Deg8 are two members of the HtrA proteases, a family of oligomeric serine endopeptidases that are involved in a variety of protein quality-control processes. These two HtrA proteases are located in the thylakoid lumen and participate in high-light stress responses by collaborating with other chloroplast proteins. Deg5 and Deg8 degrade photodamaged D1 protein of the photosystem II reaction centre, allowing its in situ replacement. Here, the crystal structures of Arabidopsis thaliana Deg5 (S266A) and Deg8 (S292A) are reported at 2.6 and 2.0 Å resolution, respectively. The Deg5 trimer contains two calcium ions in a central channel, suggesting a link between photodamage control and calcium ions in chloroplasts. Previous structures of HtrA proteases have indicated that their regulation usually requires C-terminal PDZ domain(s). Deg5 is unique in that it contains no PDZ domain and the trimeric structure of Deg5 (S266A) reveals a novel catalytic triad conformation. A similar triad conformation is observed in the hexameric structure of the single PDZ-domain-containing Deg8 (S292A). These findings suggest a novel activation mechanism for plant HtrA proteases and provide structural clues to their function in light-stress response.

  5. Neutron irradiation of silicon diodes at temperatures of +20deg C and -20deg C

    Energy Technology Data Exchange (ETDEWEB)

    Anghinolfi, F.; Glaser, M.; Heijne, E.H.M.; Jarron, P.; Lemeilleur, F.; Occelli, E.; Poppleton, A. (CERN, Geneva (Switzerland)); Bardos, R.; Gorfine, G.; Moorhead, G.; Taylor, G.; Tovey, S. (School of Physics, Univ. Melbourne, Parkville (Australia)); Bates, S.J.; Munday, D.J.; Parker, M.A. (Cavendish Lab., Univ. Cambridge (United Kingdom)); Bonino, R.; Clark, A.G.; Wu, X. (DPNC, Univ. Geneva (Switzerland)); Claussen, N.; Fretwurst, E.; Lindstroem, G.; Papendick, B.; Schulz, T.; Wunstorf, R. (Inst. fuer Experimentalphysik, Univ. Hamburg (Germany)); Goessling, C.; Klingenberg, R.; Pagel, H.; Pollmann, D.; Rolf, A. (Inst. fuer Physik, Univ. Dortmund (Germany)); Scampoli, P. (Dipt. di Fisica, Univ. Perugia (Italy) INFN, Sezione Perugia (Italy)); Weidberg, A.R. (Dept. of Nuclear Physics, Oxford Univ. (United Kingdom)); RD2 Collaboration

    1993-03-01

    We report measurements of the behaviour of silicon diodes when exposed to integrated neutron doses of up to 5x10[sup 13] neutrons/cm[sup 2]. The measurements have been made at diode temperatures between room temperature and -20deg C. From measurements of the diode leakage current and depletion voltage, and consequent evaluations of the effective impurity concentration, the temperature dependence of these quantities is discussed in terms of the annealing behaviour of the diodes. Comments are made on the suitability of silicon as a detector medium for particle physics experiments at future accelerators. (orig.).

  6. DegP Chaperone Suppresses Toxic Inner Membrane Translocation Intermediates

    Science.gov (United States)

    Braselmann, Esther; Chaney, Julie L.; Champion, Matthew M.

    2016-01-01

    The periplasm of Gram-negative bacteria includes a variety of molecular chaperones that shepherd the folding and targeting of secreted proteins. A central player of this quality control network is DegP, a protease also suggested to have a chaperone function. We serendipitously discovered that production of the Bordetella pertussis autotransporter virulence protein pertactin is lethal in Escherichia coli ΔdegP strains. We investigated specific contributions of DegP to secretion of pertactin as a model system to test the functions of DegP in vivo. The DegP chaperone activity was sufficient to restore growth during pertactin production. This chaperone dependency could be relieved by changing the pertactin signal sequence: an E. coli signal sequence leading to co-translational inner membrane (IM) translocation was sufficient to suppress lethality in the absence of DegP, whereas an E. coli post-translational signal sequence was sufficient to recapitulate the lethal phenotype. These results identify a novel connection between the DegP chaperone and the mechanism used to translocate a protein across the IM. Lethality coincided with loss of periplasmic proteins, soluble σE, and proteins regulated by this essential stress response. These results suggest post-translational IM translocation can lead to the formation of toxic periplasmic folding intermediates, which DegP can suppress. PMID:27626276

  7. DegP Chaperone Suppresses Toxic Inner Membrane Translocation Intermediates.

    Science.gov (United States)

    Braselmann, Esther; Chaney, Julie L; Champion, Matthew M; Clark, Patricia L

    2016-01-01

    The periplasm of Gram-negative bacteria includes a variety of molecular chaperones that shepherd the folding and targeting of secreted proteins. A central player of this quality control network is DegP, a protease also suggested to have a chaperone function. We serendipitously discovered that production of the Bordetella pertussis autotransporter virulence protein pertactin is lethal in Escherichia coli ΔdegP strains. We investigated specific contributions of DegP to secretion of pertactin as a model system to test the functions of DegP in vivo. The DegP chaperone activity was sufficient to restore growth during pertactin production. This chaperone dependency could be relieved by changing the pertactin signal sequence: an E. coli signal sequence leading to co-translational inner membrane (IM) translocation was sufficient to suppress lethality in the absence of DegP, whereas an E. coli post-translational signal sequence was sufficient to recapitulate the lethal phenotype. These results identify a novel connection between the DegP chaperone and the mechanism used to translocate a protein across the IM. Lethality coincided with loss of periplasmic proteins, soluble σE, and proteins regulated by this essential stress response. These results suggest post-translational IM translocation can lead to the formation of toxic periplasmic folding intermediates, which DegP can suppress.

  8. Involvement of DEG5 and DEG8 proteases in the turnover of the photosystem II reaction center D1 protein under heat stress in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    SUN XuWu; WANG LiYuan; ZHANG LiXin

    2007-01-01

    Deg5,deg8 and the double mutant,deg5deg8 of Arabidopsis thaliana were used to study the physiological role of the DEG proteases in the repair cycle of photosystem II (PSII) under heat stress. PSII activity in deg mutants showed increased sensitivity to heat stress,and the extent of this effect was greater in the double mutant,deg5deg8,than in the single mutants,deg5 and deg8. Degradation of the D1 protein was slower in the mutants than in the WT plants. Furthermore,the levels of other PSII reaction center proteins tested remained relatively stable in the mutant and WT plants following high-temperature treatment. Thus,our results indicate that DEG5 and DEG8 may have synergistic function in degradation of D1 protein under heat stress.

  9. Experimental validation of an extended Jones matrix calculus model to study the 3D structural orientation of the collagen fibers in articular cartilage using polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Kasaragod, Deepa K; Lu, Zenghai; Jacobs, James; Matcher, Stephen J

    2012-03-01

    We report results to verify a theoretical framework to analyze the 3D depth-wise structural organization of collagen fibers in articular cartilage using polarization-sensitive optical coherence tomography. Apparent birefringence data obtained from multi-angle measurements using a time domain polarization-sensitive optical coherence tomography system has been compared with simulated data based on the extended Jones matrix calculus. Experimental data has been shown to agree with the lamellar model previously proposed for the cartilage microstructure based on scanning electron microscopy data. This tool could have potential application in mapping the collagen structural orientation information of cartilage non-invasively during arthroscopy.

  10. La formazione iniziale degli insegnanti in Italia

    Directory of Open Access Journals (Sweden)

    Carlo Cappa

    2013-07-01

    Full Text Available L’articolo è diviso in tre parti. La prima presenta gli elementi storici e di sfondo che occorre tenere presenti per comprendere l’evoluzione della formazione iniziale degli insegnanti verso gli attuali modelli, che pur essendo oggi tutti gestiti dalle università conservano una sensibile diversità a seconda che si tratti di formare maestri per la scuola dell’infanzia e primaria oppure professori di scuola secondaria di primo e secondo grado. La seconda parte analizza il passaggio, maturato tra la fine del secolo scorso e l’inizio del XXI secolo, della formazione dei maestri dalla scuola secondaria (Istituto magistrale all’università (Corso di laurea in Scienze della formazione primaria, e l’istituzione delle Scuole di Specializzazione per l’Insegnamento Secondario (SSIS fino alla soppressione di queste ultime, avvenuta nel 2009. La terza parte presenta il quadro attuale della formazione iniziale dei docenti in Italia con riguardo soprattutto agli insegnanti della scuola secondaria, per i quali – a differenza che per i maestri - sono intervenute dal 2010 importanti innovazioni legislative. Le SSIS sono state infatti sostituite con il Tirocinio Formativo Attivo (TFA, attualmente in fase di attuazione da parte delle università. Nella parte finale dell’articolo si traccia un primo bilancio dell’esperienza del TFA e si indicano alcuni problemi aperti. Il focus rimane sostanzialmente sulla formazione iniziale, in quanto in Italia la formazione in servizio, che pure non è del tutto assente, non è mai stata oggetto di una normativa né di una azione organica, ma avviene, quando avviene, sulla base di iniziative di specifici gruppi o associazioni.The article is organised in three parts. The first one illustrates the historical features and the institutional and political background that have to be taken into account in order to understand how initial teacher education and training has developed in Italy. Presently, all teacher

  11. VCSEL-powered and polarization-maintaining fiber-optic grating vector rotation sensor.

    Science.gov (United States)

    Guo, Tuan; Liu, Fu; Du, Fa; Zhang, Zhaochuan; Li, Chunjie; Guan, Bai-Ou; Albert, Jacques

    2013-08-12

    A compact fiber-optic vector rotation sensor in which a short section of polarization-maintaining (PM) fiber stub containing a straight fiber Bragg grating (FBG) is spliced to another single mode fiber without any lateral offset is proposed and experimentally demonstrated. Due to the intrinsic birefringence of the PM fiber, two well-defined resonances (i.e. orthogonally polarized FBG core modes) with wavelength separation of 0.5 nm have been achieved in reflection, and they exhibit a high sensitivity to fiber rotation. Both the orientation and the angle of rotation can be determined unambiguously via simple power detection of the relative amplitudes of the orthogonal core reflections. Meanwhile, instead of using a broadband source (BBS), the sensor is powered by a commercial vertical cavity surface emitting laser (VCSEL) with the laser wavelength matched to the PM-FBG core modes, which enables the sensor to work at much higher power levels (~15 dB better than BBS). This improves the signal-to-noise ratio considerably (~50 dB), and makes a demodulation filter unnecessary. Vector rotation measurement with a sensitivity of 0.09 dB/deg has been achieved via cost-effective single detector real time power measurement, and the unwanted power fluctuations and temperature perturbations can be effectively referenced out.

  12. Environmental Performance Of Attitude And Heading Reference Grade Fiber Optic Rotation Sensors

    Science.gov (United States)

    Goldner, Eric L.; Chin, Gene H.

    1990-02-01

    Demonstration of better than 1.0 deg/hr bias stability and 0.05 deg/rt.hr angle random walk have been achieved over temperature with a fiber optic gyro under open loop testing conditions. Based on this performance, 0.1 deg/hr bias and .02 deg/rt.hr random walk are realizable system level specifications for low-cost attitude grade IMUs in production.

  13. Flexure fatigue testing of 90 deg graphite/epoxy composites

    Science.gov (United States)

    Peck, Ann Nancy W.

    1995-01-01

    A great deal of research has been performed characterizing the in-plane fiber-dominated properties, under both static and fatigue loading, of advanced composite materials. To the author's knowledge, no study has been performed to date investigating fatigue characteristics in the transverse direction. This information is important in the design of bonded composite airframe structure where repeated, cyclic out-of-plane bending may occur. Recent tests characterizing skin/stringer debond failures in reinforced composite panels where the dominant loading in the skin is flexure along the edge of the frame indicate failure initiated either in the skin or else the flange, near the flange tip. When failure initiated in the skin, transverse matrix cracks formed in the surface skin ply closest to the flange and either initiated delaminations or created matrix cracks in the next lower ply, which in turn initiated delaminations. When failure initiated in the flanges, transverse cracks formed in the flange angle ply closest to the skin and initiated delamination. In no configuration did failure propagate through the adhesive bond layer. For the examined skin/flange configurations, the maximum transverse tension stress at failure correlates very well with the transverse tension strength of the composites. Transverse tension strength (static) data of graphite epoxy composites have been shown to vary with the volume of material stressed. As the volume of material stressed increased, the strength decreased. A volumetric scaling law based on Weibull statistics can be used to predict the transverse strength measurements. The volume dependence reflects the presence of inherent flaws in the microstructure of the lamina. A similar approach may be taken to determine a volume scale effect on the transverse tension fatigue behavior of graphite/epoxy composites. The objective of this work is to generate transverse tension strength and fatigue S-N characteristics for composite materials using

  14. Long fiber polymer composite property calculation in injection molding simulation

    Science.gov (United States)

    Jin, Xiaoshi; Wang, Jin; Han, Sejin

    2013-05-01

    Long fiber filled polymer composite materials have attracted a great attention and usage in recent years. However, the injection and compression molded long fiber composite materials possess complex microstructures that include spatial variations in fiber orientation and length. This paper presents the recent implemented anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model for predicting fiber orientation distribution[1] and a newly developed fiber breakage model[2] for predicting fiber length distribution in injection and compression molding simulation, and Eshelby-Mori-Tanaka model[3,4] with fiber-matrix de-bonding model[5] have been implemented to calculate the long fiber composite property distribution with predicted fiber orientation and fiber length distributions. A validation study on fiber orientation, fiber breakage and mechanical property distributions are given with injection molding process simulation.

  15. Optimization of Picrosirius red staining protocol to determine collagen fiber orientations in vaginal and uterine cervical tissues by Mueller polarized microscopy.

    Science.gov (United States)

    Nazac, André; Bancelin, Stéphane; Teig, Benjamin; Ibrahim, Bicher Haj; Fernandez, Hervé; Schanne-Klein, Marie-Claire; De Martino, Antonello

    2015-08-01

    Polarized microscopy provides unique information on anisotropic samples. In its most complete implementation, namely Mueller microscopy, this technique is well suited for the visualization of fibrillar proteins orientations, with collagen in the first place. However, the intrinsic optical anisotropy of unstained tissues has to be enhanced by Picrosirius Red (PR) staining to enable Mueller measurements. In this work, we compared the orientation mapping provided by Mueller and second harmonic generation (SHG) microscopies on PR stained samples of vaginal and uterine cervix tissues. SHG is a multiphoton technique that is highly specific to fibrillar collagen, and was taken as the "gold standard" for its visualization. We showed that Mueller microscopy can be safely used to determine collagen orientation in PR stained cervical tissue. In contrast, in vaginal samples, Mueller microscopy revealed orientations not only of collagen but also of other anisotropic structures. Thus PR is not fully specific to collagen, which necessitates comparison to SHG microscopy in every type of tissue. In addition to this study of PR specificity, we determined the optimal values of the staining parameters. We found that staining times of 5 min, and sample thicknesses of 5 µm were sufficient in cervical and vaginal tissues.

  16. Assessment of Fiber Distribution in Steel Fiber Mortar Using Image Analysis

    Institute of Scientific and Technical Information of China (English)

    LIU Jianzhong; SUN Wei; MIAO Changwen; LIU Jiaping; LI Changfeng

    2012-01-01

    Abstratct:A new test method was introduced to measure fiber distribution in steel fiber reinforced mortar by using image analysis technique.Through specimen preparation,image acquisition,fiber extraction,and measurement of related fiber parameters,quantitative analysis of fiber distribution could be obtained by two parameters,namely dispersion coefficient and orientation factor.Effect of boundaries,size and steel fiber content on fiber distribution was discussed.Results showed that,steel fiber distribution was affected by boundary effect,which would be weakened with the increase of specimen size.If the length and width remained constant,the specimen height had a significant effect on orientation factor of fiber,while its influence on dispersion coefficient was not so obvious.With the increase of steel fiber content,dispersion coefficient decreased slightly,and orientation factor deviated from 0.5.

  17. Toward high performance graphene fibers.

    Science.gov (United States)

    Chen, Li; He, Yuling; Chai, Songgang; Qiang, Hong; Chen, Feng; Fu, Qiang

    2013-07-07

    Two-dimensional graphene and graphene-based materials have attracted tremendous interest, hence much attention has been drawn to exploring and applying their exceptional characteristics and properties. Integration of graphene sheets into macroscopic fibers is a very important way for their application and has received increasing interest. In this study, neat and macroscopic graphene fibers were continuously spun from graphene oxide (GO) suspensions followed by chemical reduction. By varying wet-spinning conditions, a series of graphene fibers were prepared, then, the structural features, mechanical and electrical performances of the fibers were investigated. We found the orientation of graphene sheets, the interaction between inter-fiber graphene sheets and the defects in the fibers have a pronounced effect on the properties of the fibers. Graphene fibers with excellent mechanical and electrical properties will yield great advances in high-tech applications. These findings provide guidance for the future production of high performance graphene fibers.

  18. The family of Deg/HtrA proteases in plants

    Directory of Open Access Journals (Sweden)

    Schuhmann Holger

    2012-04-01

    Full Text Available Abstract Background The Deg/HtrA family of ATP-independent serine endopeptidases is present in nearly all organisms from bacteria to human and vascular plants. In recent years, multiple deg/htrA protease genes were identified in various plant genomes. During genome annotations most proteases were named according to the order of discovery, hence the same names were sometimes given to different types of Deg/HtrA enzymes in different plant species. This can easily lead to false inference of individual protease functions based solely on a shared name. Therefore, the existing names and classification of these proteolytic enzymes does not meet our current needs and a phylogeny-based standardized nomenclature is required. Results Using phylogenetic and domain arrangement analysis, we improved the nomenclature of the Deg/HtrA protease family, standardized protease names based on their well-established nomenclature in Arabidopsis thaliana, and clarified the evolutionary relationship between orthologous enzymes from various photosynthetic organisms across several divergent systematic groups, including dicots, a monocot, a moss and a green alga. Furthermore, we identified a “core set” of eight proteases shared by all organisms examined here that might provide all the proteolytic potential of Deg/HtrA proteases necessary for a hypothetical plant cell. Conclusions In our proposed nomenclature, the evolutionarily closest orthologs have the same protease name, simplifying scientific communication when comparing different plant species and allowing for more reliable inference of protease functions. Further, we proposed that the high number of Deg/HtrA proteases in plants is mainly due to gene duplications unique to the respective organism.

  19. Limiting Global Warming to 2 deg C and Beyond

    Science.gov (United States)

    Lea, D. W.

    2011-12-01

    This presentation addresses the question of how feasible is it to limit global warming to a specific temperature rise, whether 1.5, 2 or 3 deg C. Inherent in the idea of limiting global warming to a specific temperature level is the notion that future GHG emissions will be subject to a top-down international agreement. In the post-Copenhagen era, however, such an agreement is unlikely, and a bottoms-up approach of national pledges will likely have to serve as a surrogate for achieving emissions reduction. In this case, an additional question is what temperature targets are realistic under scenarios that are bounded by achievable national pledges as opposed to binding mandates. The question of feasibility depends largely on future emission pathways of CO2, other GHGs, black carbon and aerosols. Those pathways depend on many societal, technological and economic factors, but it is likely that the ultimate limiting factor is the maximum possible rate of absolute emission reduction. That rate is limited by how rapidly energy infrastructure can be turned over. Most studies suggest that an absolute emission reduction rate of 3.5% is the highest rate achievable. Climate sensitivity and the current cooling effect of aerosols and earth system responses such as the rate of ocean heat uptake and carbon cycle feedbacks determine how a specific emissions pathway translates into probable climate change. A useful framework for CO2 alone is provided by the newly emerging paradigm of cumulative emissions, which holds that peak temperature can be largely predicted by the total amount of carbon emitted, regardless of pathway. Most studies suggest that 1 Tt of cumulative carbon is equivalent to ~2 deg of peak warming. A consideration of these factors suggests that limiting warming to 1.5 deg C is no longer possible under any feasible economic scenario. For one, currently emitted GHGs are equivalent to a ~1.3 deg C warming commitment. This leaves very little room for future emissions

  20. Tropospheric ozone over a tropical Atlantic station in the Northern Hemisphere: Paramaribo, Surinam (6 deg N, 55 deg W)

    Energy Technology Data Exchange (ETDEWEB)

    Peters, W.; Krol, M.C. [Inst. for Marine and Atmospheric Research Utrecht (Netherlands); Fortuin, J.P.F.; Kelder, H.M. [Koninklijke Nederlandse Meteorologische Dienst, De Bilt (Netherlands); Thompson, A.M. [Goddard Space Flight Center, NASA, Greenbelt, MD (United States); Becker, C.R. [Meteorologische Dienst Suriname, Paramaribo (Suriname); Lelieveld, J.; Crutzen, P.J. [Max Planck Inst. fuer Chemie, Mainz (Germany)

    2004-02-01

    We present an analysis of 2.5 yr of weekly ozone soundings conducted at a new monitoring station in Paramaribo, Surinam (6 deg N, 55 deg W). This is currently one of only three ozone sounding stations in the Northern Hemisphere (NH) tropics, and the only one in the equatorial Atlantic region. Paramaribo is part of the Southern Hemisphere Additional Ozone Sounding program (SHADOZ). Owing to its position close to the equator, the inter-tropical convergence zone (ITCZ) passes over Paramaribo twice per year, which results in a semi-annual seasonality of many parameters including relative humidity and ozone. The dataset from Paramaribo is used to: (1) evaluate the ozone variability relative to precipitation, atmospheric circulation patterns and biomass burning; (2) contrast ozone at the NH equatorial Atlantic with that at nearby Southern Hemisphere (SH) stations Natal (6 deg S, 35 deg W) and Ascension (8 deg S, 14 deg W); (3) compare the seasonality of tropospheric ozone with a satellite-derived ozone product: tropical tropospheric ozone columns from the modified residual method (MR-TTOC). We find that Paramaribo is a distinctly Atlantic station. Despite its position north of the equator, it resembles nearby SH stations during most of the year. Transport patterns in the lower and middle troposphere during February and March differ from SH stations, which leads to a seasonality of ozone with two maxima. MR-TTOC over Paramaribo does not match the observed seasonality of ozone due to the use of a SH ozone sonde climatology in the MR method. The Paramaribo ozone record is used to suggest an improvement for Northern Hemisphere MR-TTOC retrievals. We conclude that station Paramaribo shows unique features in the region, and clearly adds new information to the existing SHADOZ record.

  1. Radio identification of decameter-wave sources. II: The 30degdeg declination interval

    CERN Document Server

    Verkhodanov, O V; Andernach, H; 10.1134/S1990341309010052

    2009-01-01

    This paper is dedicated to the identification of decameter-wave sources of the UTR catalog within declination interval 30degdeg. UTR sources are cross-identified with CATS database catalogs within 40'x40' error boxes. The sources are deblended using the data on the coordinates of the objects and the behavior of their continuum radio spectra. The spectra of 876 sources are derived and fitted by standard analytical functions. Of these sources, 221 objects have straight-line spectra with spectral indices alpha<-1.0. All objects are catalogued and stored in the CATS database.

  2. Danish orientalism

    National Research Council Canada - National Science Library

    Zerlang, Martin

    2006-01-01

    Orientalism became an important current in nineteenth-century Danish culture, but although it was contemporaneous with the orientalism of the leading European nations - Great Britain, France, Germany...

  3. Fiber optics welder

    Science.gov (United States)

    Higgins, R.W.; Robichaud, R.E.

    A system is described for welding fiber optic waveguides together. The ends of the two fibers to be joined together are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 45/sup 0/ angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation.

  4. Interaction of human smooth muscle cells with nanofibrous scaffolds: Effect of fiber orientation on cell adhesion, proliferation, and functional gene expression.

    Science.gov (United States)

    Kuppan, Purushothaman; Sethuraman, Swaminathan; Krishnan, Uma Maheswari

    2015-07-01

    Poly(ɛ-caprolactone) (PCL) and PCL-gelatin random and aligned nanofibers with diameters in the range of 200-400 nm were developed through electrospinning. Mechanical properties of aligned PCL and PCL-gelatin nanofibers were compared, and it was found that aligned PCL nanofibers showed significantly higher tensile strength and Young's modulus than the PCL-gelatin nanofiber system (p muscle cells were cultured on the random and aligned PCL-gelatin nanofibers and evaluated for adhesion, orientation, morphology, viability, proliferation and gene expression. Our results demonstrate that PCL-gelatin promotes higher cell adhesion and proliferation than the PCL nanofibers after 3, 7, and 10 days of culture. Aligned topography favored orientation of the cells along their directions and cell stretching was better in aligned nanofibers than the random nanofibers. The upregulation of α-actin, myosin heavy chain, collagen type I, and elastin genes demonstrate good cell-matrix interactions in both random and aligned scaffolds. Therefore, the present study concludes that aligned PCL-gelatin nanofibers could serve as potential scaffolding for culture of smooth muscle cells and may promote functional regeneration of tubular organs. © 2014 Wiley Periodicals, Inc.

  5. Embrittlement of reduced-activation ferritic/martensitic steels irradiated in HFIR at 300 deg. C and 400 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L. E-mail: ku2@ornl.gov; Sokolov, M.A.; Shiba, K.; Miwa, Y.; Robertson, J.P

    2000-12-01

    Miniature tensile and Charpy specimens of four ferritic/martensitic steels were irradiated at 300 deg. C and 400 deg. C in the high flux isotope reactor (HFIR) to a maximum dose of {approx}12 dpa. The steels were standard F82H (F82H-Std), a modified F82H (F82H-Mod), ORNL 9Cr-2WVTa, and 9Cr-2WVTa-2Ni, the 9Cr-2WVTa containing 2% Ni to produce helium by (n,{alpha}) reactions with thermal neutrons. More helium was produced in the F82H-Std than the F82H-Mod because of the presence of boron. Irradiation embrittlement in the form of an increase in the ductile-brittle transition temperature ({delta}DBTT) and a decrease in the upper-shelf energy (USE) occurred for all the steels. The two F82H steels had similar {delta}DBTTs after irradiation at 300 deg. C, but after irradiation at 400 deg. C, the {delta}DBTT for F82H-Std was less than for F82H-Mod. Under these irradiation conditions, little effect of the extra helium in the F82H-Std could be discerned. Less embrittlement was observed for 9Cr-2WVTa steel irradiated at 400 deg. C than for the two F82H steels. The 9Cr-2WVTa-2Ni steel with {approx}115 appm He had a larger {delta}DBTT than the 9Cr-2WVTa with {approx}5 appm He, indicating a possible helium effect.

  6. Modello metodologico per il monitoraggio degli incidenti stradali in Trentino

    Directory of Open Access Journals (Sweden)

    P. Fateh-Moghadam

    2003-05-01

    Full Text Available

    Obiettivi: realizzazione di un’infrastruttura informatica, per l’unificazione tempestiva dei flussi sugli incidenti stradali (ISTAT-ACI e sanitari con la georeferenziazione degli eventi a partire dall’anno 2000.

    Materiali e Metodi: dall’archivio di Trentino emergenza sono stati estratti gli interventi per incidente stradale selezionando la combinazione: descrizione patologica: “traumatismi”, tipologia luogo: “strada”, tipologia incidente. Dai dati di ogni Pronto soccorso è stato costruito un archivio unico contenente il totale degli accessi e sono stati estratti gli accessi per “incidente stradale” e quelli per lesioni accidentali in generale. Dall’archivio SDO si sono selezionati sia i ricoveri con il criterio “3” alla variabile mtraav (=incidente stradale che quelli per traumatismi.

    Nell’ambito del progetto “Metodi informatici predittivi per la mitigazione del rischio da incidenti stradali” (Mitris, finanziato dal Ministero della Salute, è stata realizzata l’immissione tramite interfaccia internet o decodifica automatica dei verbali informatizzati delle Forze dell’ordine, e la contestuale realizzazione di un interfaccia WebGIS
    in grado di visualizzare la localizzazione degli incidenti stradali.

    Risultati: tramite la combinazione “data nascita”,
    “data incidente”, “sesso” è stato eseguito un primo collegamento tra gli archivi. Aggiungendo alla data incidente uno o più giorni, è stato costruito un nuovo archivio PS contenente il 97,4% degli eventi raccolti dalle forze dell’Ordine e contenuti nel data base Mitris. Approccio analogo è stato seguito per il linkage con SDO e 118. Tramite interfaccia WebGIS è stata creata una mappa degli incidenti interrogabile on-line, che oltre alla semplice localizzazione riporta dinamica e esiti con possibilità di produrre statistiche e grafici. Il sistema copre attualmente

  7. An evaluation of the +/-45 deg tensile test for the determination of the in-plane shear strength of composite materials

    Science.gov (United States)

    Kellas, S.; Morton, J.; Jackson, K. E.

    1991-01-01

    The applicability of the +/-45 deg tensile test for the determination of the in-plane shear strength of advanced composite laminates is studied. The assumptions used for the development of the shear strength formulas were examined, and factors such as the specimen geometry and stacking sequence were assessed experimentally. It was found that the strength of symmetric and balanced +/-45 deg laminates depends primarily upon the specimen thickness rather than the specimen width. These findings have important implications for the +/-45 deg tensile test which is recommended by several organizations for the determination of the in-plane shear stress/strain response and the shear strength of continuous fiber reinforced composites. Modifications to the recommended practices for specimen selection and shear strength determination are suggested.

  8. Immagini dinamiche: appunti per un catalogo degli usi didattici

    Directory of Open Access Journals (Sweden)

    Filippo Bruni

    2013-03-01

    Full Text Available Le immagini dinamiche costituiscono un’importante risorsa per le attività didattiche. A partire da una riflessione storica, si evidenzia in primo luogo l’importanza di un loro uso efficace alla luce della classificazione operata da Clark e Lyons. In secondo luogo si segnalano alcune attività emergenti legate alla documentazione, al digital storytelling e alla formazione degli insegnanti.

  9. Technical Note: Using DEG CPCs at upper tropospheric temperatures

    CERN Document Server

    Wimmer, D; Nieminen, T; Duplissy, J; Ehrhart, S; Almeida, J; Rondo, L; Franchin, A; Kreissl, F; Manninen, H E; Kulmala, M; Curtius, J; Petäjä, T

    2014-01-01

    Over the last few years, several Condensation Particle Counters (CPC) capable of measuring in the sub-3 nm size range have been developed. Here we study the performance of Diethylene glycol (DEG) based CPCs at different temperatures during Cosmics Leaving Outdoor Droplets (CLOUD) measurements at CERN. The data shown here is the first set of verification measurements for sub-3 nm CPCs under upper tropospheric temperatures using atmospherically relevant aerosol particles. To put the results in perspective we calibrated the DEG-CPC at room temperature, resulting in a cut-off diameter of 1.4 nm. All diameters refer to mobility equivalent diameters in this manuscript. At upper tropospheric temperatures between −25 °C and −65 °C, we found cut-off sizes in the range of 2.5 and 2.8 nm. Due to low number concentration after size classification, the cut-off diameters have a high uncertainty (±0.3 nm) associated with them. Operating two laminar flow DEG CPCs with different cut-off sizes together with other aeroso...

  10. Book review. La forma degli animali. Adolf Portmann

    Directory of Open Access Journals (Sweden)

    Manuel Graziani

    2013-09-01

    Full Text Available Nel 1931 il biologo Adolf Portmann era già talmente noto a livello internazionale per le sue ricerche da guadagnarsi la cattedra in zoologia nell'università della sua città natale, Basilea, all'età di appena 34 anni. All'attività di docente universitario ha sempre affiancato un'originale riflessione sul significato delle scienze della vita, imponendosi come una delle figure chiave nel dibattito tra biologia teoretica, estetica e antropologia filosofica. La forma degli animali, la sua opera più celebre, si pone al confine tra varie discipline e conserva un grande interesse ancora oggi che il dialogo tra estetica e biologia si è fatto nuovamente intenso. Pubblicata nel 1948 e in forma ampliata nel 1960 (da cui deriva questa prima edizione italiana a cura di Pietro Conte l'opera rappresenta il frutto più maturo delle sue ricerche "interdisciplinari".Un saggio che nasce dall'insoddisfazione nei confronti dei paradigmi scientifici consolidati e che ripropone l'idea morfologica in biologia sulla scorta del pensiero di J. W. Goethe il quale affermava che "tutto ciò che è deve anche dar cenno di sé e mostrarsi". Adolf Portmann è un convinto sostenitore che dalla forma si possano dedurne le complessive caratteristiche interne ed esterne degli animali. Secondo questa prospettiva la peculiare fisionomia dell'organismo dipende dalla congiunzione delle sue parti e dalle loro reciproche funzioni. Tuttavia l'autore non vede nello studio della forma l'alternativa al funzionalismo quanto, piuttosto, il suo necessario bilanciamento come dichiara nell'introduzione: "… per giungere alla conoscenza della vita animale di strade ce ne sono molte, e tutte possono contribuire ad arricchire la nostra esperienza. Questo lavoro si occupa della forma degli animali e si propone di mettere in luce la peculiare natura dell'aspetto visibile. Ci sono persone che si dedicano allo studio degli animali, conoscono moltissime specie, hanno imparato centinaia di nomi e

  11. TPS/LDPE blends reinforced with lignocellulose fibers; Compositos TPS/LDPE reforcados com fibras lignocelulosicas

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, G.K.; Andrade, C.T., E-mail: kloc@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Eloisa Mano

    2010-07-01

    Because of their abundance, availability, low abrasiveness and mechanical properties, cellulose fibers have been frequently chosen as reinforcing fillers in composites. Castor bean cake, the residue from biodiesel production, is rich in lignocellulose fibers and proteins. One of these proteins is ricin, a toxin protein. In this work, ricin was denatured by heat treatment in water at 90 deg C for 4 h. Thermoplastic starch (TPS), low density polyethylene (LDPE), maleated polyethylene (used as the compatibilizing agent), and an organophilic clay were processed in the presence of different contents of heat treated castor bean cake. Processing was carried out in a single-screw extruder, at 400 rpm, with heat zones at 130 deg C, 135 deg C, 135 deg C and 130 deg C (from feed zone to die end). The structural and mechanical properties of the resulting polymeric composites were investigated, and revealed the reinforcing effect of the partially purified cellulose fibers. (author)

  12. Geology of the Delta, Escalante, Price, Richfield and Salina 1 deg x 2 deg NTMS quadrangles, Utah

    Science.gov (United States)

    Thayer, P. A.

    1981-11-01

    The National Uranium Resource Evaluation (NURE) program was established to evaluate domestic uranium resources in the continental United States and to identify areas favorable for uranium exploration. The Grand Junction Office of the Department of Energy is responsible for administering the program. The Savannah River Laboratory (SRL) is responsible for hydrogeochemical and stream-sediment reconnaissance (HSSR) of 3.9 million sq km (1,500,000 mi(2)) in 37 eastern and western states. This document provides geologic and mineral resources reports for the Delta, Escalante, Price, Richfield, and Salina 1 deg x 2 deg National Topographic Map Series quadrangles, Utah. The purpose of these reports is to provide background geologic and mineral resources information to aid in the interpretation of NURE geochemical reconnaissance data. Except for the Escalante Quadrangle, each report is accompanied by a geologic map and a mineral locality map (Plates 1-8, in pocket).

  13. Self-pumped phase conjugation and four-wave mixing in 0- and 45-deg-cut n-type BaTiO3:Co

    Science.gov (United States)

    Garrett, M. H.; Chang, J. Y.; Jenssen, H. P.; Warde, C.

    1993-01-01

    Relatively fast self-pumped phase-conjugate and four-wave-mixing rise times are reported in n-type cobalt-doped barium titanate. With the crystal oriented in a 45-deg cut as compared with the same crystal in a 0-deg cut we find a factor of 3 decrease in the 0-90-percent rise time to 800 ms with 25-mW input power at 514.5 nm. Also, the self-pumped phase-conjugate reflectivity increases from 20 to 40 percent. We deduce that the phase conjugation is from internally seeded stimulated photorefractive backscattering. The four-wave-mixing rise time of the 45-deg-cut crystal is 4 ms with a reflectivity of 48 percent when the pumping beams are derived from self-pumped phase conjugation that has an input power of 25 mW.

  14. Technical Note: Using DEG-CPCs at upper tropospheric temperatures

    Science.gov (United States)

    Wimmer, D.; Lehtipalo, K.; Nieminen, T.; Duplissy, J.; Ehrhart, S.; Almeida, J.; Rondo, L.; Franchin, A.; Kreissl, F.; Bianchi, F.; Manninen, H. E.; Kulmala, M.; Curtius, J.; Petäjä, T.

    2015-07-01

    Over the last few years, several condensation particle counters (CPCs) capable of measuring in the sub-3 nm size range have been developed. Here we study the performance of CPCs based on diethylene glycol (DEG) at different temperatures during Cosmics Leaving OUtdoor Droplets (CLOUD) measurements at CERN. The data shown here are the first set of verification measurements for sub-3 nm CPCs under upper tropospheric temperatures using atmospherically relevant aerosol particles. To put the results in perspective we calibrated the DEG-CPC at room temperature, resulting in a cut-off diameter of 1.4 nm. All diameters refer to mobility equivalent diameters in this paper. At upper tropospheric temperatures ranging from 246.15 K to 207.15 K, we found cut-off sizes relative to a particle size magnifier in the range of 2.5 to 2.8 nm. Due to low number concentration after size classification, the cut-off diameters have a high uncertainty (±0.3 nm) associated with them. Operating two laminar flow DEG-CPCs with different cut-off sizes together with other aerosol instruments, we looked at the growth rates of aerosol population in the CLOUD chamber for particles smaller than 10 nm at different temperatures. A more consistent picture emerged when we normalized the growth rates to a fixed gas-phase sulfuric acid concentration. All of the instruments detected larger growth rates at lower temperatures, and the observed growth rates decreased as a function of temperature, showing a similar trend for all instruments. The theoretical calculations had a similar but much smaller temperature dependency.

  15. Drops spreading on flexible fibers

    Science.gov (United States)

    Somszor, Katarzyna; Boulogne, François; Sauret, Alban; Dressaire, Emilie; Stone, Howard

    2015-11-01

    Fibrous media are encountered in many engineered systems such as textile, paper and insulating materials. In most of these materials, fibers are randomly oriented and form a complex network in which drops of wetting liquid tend to accumulate at the nodes of the network. Here we investigate the role of the fiber flexibility on the spreading of a small volume of liquid on a pair of crossed flexible fibers. A drop of silicone oil is dispensed at the point of contact of the fibers and we characterize the liquid morphologies as we vary the volume of liquid, the angle between the fibers, and the length and bending modulus of the fibers. Drop morphologies previously reported for rigid fibers, i.e. a drop, a column and a mixed morphology, are also observed on flexible fibers with modified domains of existence. Moreover, at small inclination angles of the fibers, a new behavior is observed: the fibers bend and collapse. Depending on the volume, the liquid can adopt a column or a mixed morphology on the collapsed fibers. We rationalize our observations with a model based on energetic considerations. Our study suggests that the fiber flexibility adds a rich variety of behaviors that can be crucial for industrial applications.

  16. Mutations suppressing the loss of DegQ function in Bacillus subtilis (natto) poly-γ-glutamate synthesis.

    Science.gov (United States)

    Do, Thi-Huyen; Suzuki, Yuki; Abe, Naoki; Kaneko, Jun; Itoh, Yoshifumi; Kimura, Keitarou

    2011-12-01

    The degQ gene of Bacillus subtilis (natto), encoding a small peptide of 46 amino acids, is essential for the synthesis of extracellular poly-gamma-glutamate (γPGA). To elucidate the role of DegQ in γPGA synthesis, we knocked out the degQ gene in Bacillus subtilis (natto) and screened for suppressor mutations that restored γPGA synthesis in the absence of DegQ. Suppressor mutations were found in degS, the receptor kinase gene of the DegS-DegU two-component system. Recombinant DegS-His(6) mutant proteins were expressed in Escherichia coli cells and subjected to an in vitro phosphorylation assay. Compared with the wild type, mutant DegS-His(6) proteins showed higher levels of autophosphorylation (R208Q, M195I, L248F, and D250N), reduced autodephosphorylation (D250N), reduced phosphatase activity toward DegU, or a reduced ability to stimulate the autodephosphorylation activity of DegU (R208Q, D249G, M195I, L248F, and D250N) and stabilized DegU in the phosphorylated form. These mutant DegS proteins mimic the effect of DegQ on wild-type DegSU in vitro. Interestingly, DegQ stabilizes phosphorylated DegS only in the presence of DegU, indicating a complex interaction of these three proteins.

  17. Mutations Suppressing the Loss of DegQ Function in Bacillus subtilis (natto) Poly-γ-Glutamate Synthesis ▿ †

    Science.gov (United States)

    Do, Thi-Huyen; Suzuki, Yuki; Abe, Naoki; Kaneko, Jun; Itoh, Yoshifumi; Kimura, Keitarou

    2011-01-01

    The degQ gene of Bacillus subtilis (natto), encoding a small peptide of 46 amino acids, is essential for the synthesis of extracellular poly-gamma-glutamate (γPGA). To elucidate the role of DegQ in γPGA synthesis, we knocked out the degQ gene in Bacillus subtilis (natto) and screened for suppressor mutations that restored γPGA synthesis in the absence of DegQ. Suppressor mutations were found in degS, the receptor kinase gene of the DegS-DegU two-component system. Recombinant DegS-His6 mutant proteins were expressed in Escherichia coli cells and subjected to an in vitro phosphorylation assay. Compared with the wild type, mutant DegS-His6 proteins showed higher levels of autophosphorylation (R208Q, M195I, L248F, and D250N), reduced autodephosphorylation (D250N), reduced phosphatase activity toward DegU, or a reduced ability to stimulate the autodephosphorylation activity of DegU (R208Q, D249G, M195I, L248F, and D250N) and stabilized DegU in the phosphorylated form. These mutant DegS proteins mimic the effect of DegQ on wild-type DegSU in vitro. Interestingly, DegQ stabilizes phosphorylated DegS only in the presence of DegU, indicating a complex interaction of these three proteins. PMID:21965392

  18. The Codice digitale degli archivi veronesi. A research instrument

    Directory of Open Access Journals (Sweden)

    Andrea Brugnoli

    2014-04-01

    Full Text Available The Codice digitale degli archivi veronesi (Verona’s archives digital code ‹http://cdavr.dtesis.univr.it› makes available online the digital reproductions of the documents produced by corporate bodies and family of Verona between the eighth and twelfth century. The framework of the site reflects the current organisation of the archives. A brief description of the circumstances around the creation of each archive, the corporate body or individual responsible for it and its structure is provided. Each archival unit is identified by its key elements: chronological date, name and qualification of the notary, original/copy, main editions.

  19. The Codice digitale degli archivi veronesi. A research instrument

    Directory of Open Access Journals (Sweden)

    Andrea Brugnoli

    2014-04-01

    Full Text Available The Codice digitale degli archivi veronesi (Verona’s archives digital code ‹http://cdavr.dtesis.univr.it› makes available online the digital reproductions of the documents produced by corporate bodies and family of Verona between the eighth and twelfth century. The framework of the site reflects the current organisation of the archives. A brief description of the circumstances around the creation of each archive, the corporate body or individual responsible for it and its structure is provided. Each archival unit is identified by its key elements: chronological date, name and qualification of the notary, original/copy, main editions.

  20. Islam, rappresentanza degli interessi religiosi e diritto comune europeo *

    Directory of Open Access Journals (Sweden)

    Gianfranco Macrì

    2011-03-01

    Full Text Available Contributo destinato alla pubblicazione negli Atti del Convegno: Europa e Islam. Ridiscutere i fondamenti per la disciplina delle libertà religiose, svoltosi a Salerno il 3 dicembre 2007.SOMMARIO: Premessa - 1. La società «reticolare» europea: sistema di governance e valori unificanti - 2. Europa e fenomeno religioso - 3. La sostanza del Trattato di Lisbona e il ruolo delle organizzazioni religiose - 4. Il dibattito interno all’Islam europeo - 5. La Carta dei musulmani d’Europa - 6. La rappresentanza degli interessi religiosi dell’Islam in Europa - Conclusioni.

  1. Numerical prediction of fiber motion in a branching channel flow of fiber suspensions

    Institute of Scientific and Technical Information of China (English)

    Jianzhong Lin; Shanliang Zhang; James A. Olson; Ron Marshall

    2005-01-01

    Fiber orientation and dispersion in the dilute fibersuspension that flows through a T-shaped branching channel are simulated numerically based on the slender-body theory. The simulated results are consistent qualitatively with the experimental data available in the literature. The results show that the spatial distribution of fibers is dependent on the fiber aspect ratio, but has no relation with the volume fraction of fiber. The content ratio of fibers near the upper wall increases monotonically with an increasing Re number, and the situation is reverse for the region near the bottom wall.The orientation of fibers depends on Re number, however, the function of fiber volume fraction and aspect ratio is negligible. The fibers near the wall and in the central region of the channel align along the flow direction at all times, but the fibers in the other parts of the channel tend to align along the flow direction only in the downstream region.

  2. Fiber tracking algorithm in combined PIV/PTV measurement of fiber suspension flow

    Science.gov (United States)

    Hoseini, Afshin Abbasi; Zavareh, Zahra; Lundell, Fredrik; Anderson, Helge I.

    2013-10-01

    A new algorithm for fiber tracking in combined PIV/PTV measurement of fiber suspension flow is proposed based on SOM neural network and is examined by synthetic images of fibers showing 2D suspension flows. There is a new idea in the algorithm to take the orientation of fibers into account for matching as well as their position. In two-phase PIV measurements of fiber-laded suspension flows, fiber tracking has a key role together with PIV measurement of fluid phase. The essential parts of fiber tracking are to correctly identify and match fibers in successive images. The development of a method in order to determine the position and orientation of fibers using steerable filter with a reasonable accuracy have already been done, [3]. The present study is concentrated in the development of an algorithm for pairing fibers in consecutive images. The method used is based on the SOM neural network that finds most likely matching link in images on the basis of feature extraction and clustering. The fundamental concept is finding the corresponding fibers with the nearest characteristics, position and angle in images. It improves not only the robustness against loss-of-pair fibers between two image frames but also reliable matching at large numbers of dispersed fibers image using one more characteristics of fibers in image, namely their orientation, in addition to their coordinate vector.

  3. Crash worthy capacity of a hybridized epoxy-glass fiber aluminum columnar tube using repeated axial resistive force

    Energy Technology Data Exchange (ETDEWEB)

    Paruka, Perowansa [Jalan Politeknik, Kota Kinabalu (Malaysia); Siswanto, Waluyo Adi [Universiti Tun Hussein Onn Malaysia, Parit Raja (Malaysia); Maleque, Md Abdul [Universiti Islam Antarabangsa Malaysia, Kuala Lumpur (Malaysia); Shah, Mohd Kamal Mohd [Universiti Malaysia Sabah, Kota Kinabalu (Malaysia)

    2015-05-15

    A combination of aluminum columnar member with composite laminate to form a hybrid structure can be used as collapsible energy absorbers especially in automotive vehicular structures to protect occupants and cargo. A key advantage of aluminum member in composite is that it provides ductile and stable plastic collapse mechanisms with progressive deformation in a stable manner by increasing energy absorption during collision. This paper presents an experimental investigation on the influence of the number of hybrid epoxy glass layers in overwrap composite columnar tubes. Three columnar tube specimens were used and fabricated by hand lay-up method. Aluminum square hollow shape was combined with externally wrapped by using an isophthalic epoxy resin reinforced with glass fiber skin with an orientation angle of 0 .deg. /90 .deg. The aluminum columnar tube was used as reference material. Crushed hybrid-composite columnar tubes were prepared using one, two, and three layers to determine the crash worthy capacity. Quasi-static crush test was conducted using INSTRON machine with an axial loading. Results showed that crush force and the number of layers were related to the enhancement of energy absorption before the collapse of columnar tubes. The energy absorption properties of the crushed hybrid-composite columnar tubes improved significantly with the addition of layers in the overwrap. Microscopic analysis on the modes of epoxy-glass fiber laminate failure was conducted by using scanning electron microscopy.

  4. Zoogeografia storica e attuale dei carnivori e degli ungulati italiani

    Directory of Open Access Journals (Sweden)

    Marco Masseti

    2003-10-01

    Full Text Available Come per la maggior parte degli altri paesi europei, anche l'attuale composizione delle specie a mammiferi italiane si prefigura in gran parte come il risultato della plurima e prolungata azione antropica condotta sull'ambiente naturale. Questa, avviatasi alcuni millenni or sono, condiziona oggi più che mai la ridefinizione degli equilibri ecologici del nostro Paese. All'interno dell'attuale teriofauna terrestre italiana viene segnalata la presenza di 18 specie di carnivori e di 9 artiodattili, che può rivelarsi in alcuni casi come il risultato di acclimatazioni e/o naturalizzazioni di specie esotiche avvenute in cronologie diverse, anche di epoca molto recente. All'interno dei confini biogeografici dell'Italia andrebbero anche annoverate quelle popolazioni del cervo pomellato medio-orientale, Axis axis (Erxleben, 1777, che sono state naturalizzate in epoca storica assai recente in Istria ed in alcune isole del golfo del Quarnaro (Brioni Maggiore, Cherso e Plauno. Considerazioni analoghe potrebbero forse essere condotte anche per la diffusione artificiale di Herpestes auropunctatus Hodgson, 1836, su alcune isole della Croazia. Le specie fitofaghe riferibili ai gruppi tassonomici dei lagomorfi e degli artiodattili, e che vengono convenzionalmente comprese nella categoria della cosiddetta "selvaggina", sono tra quelle che hanno più subito un'alterazione condotta in profondità dei quadri faunistici originari, proprio in virtù dell'interesse economico e culturale che ancora rappresentano. Nel caso particolare di queste specie di interesse venatorio ci troviamo quasi sempre di fronte a popolazioni che sono state sottoposte ad intensa gestione e che hanno subito frequenti estinzioni locali seguite da reiterate reintroduzioni. Attualmente, data l'espansione sia naturale che artificiale degli ecotipi indigeni e di quelli alloctoni, si osserva ormai una sovrapposizione degli areali, per cui sembra piuttosto difficile riuscire in

  5. Environmental oil spill sensitivity atlas for the West Greenland (68 deg.-72 deg. N) coastal zone, 2nd revised edition

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, D.; Johansen, Kasper L.; Mosbech, A.; Boertmann, D.; Wegeberg, S.

    2012-12-15

    This oil spill sensitivity atlas covers the shoreline and the offshore areas of West Greenland between 68 deg. N and 72 deg. N. The coastal zone is divided into 199 shoreline segments and the offshore zone into 8 areas. A sensitivity index value is calculated for each segment/area, and each segment/area is subsequently ranked according to four degrees of sensitivity. Besides this general ranking a number of smaller areas are especially selected as they are of particular significance, they are especially vulnerable to oil spills and they have a size making oil spill response possible. The shoreline sensitivity ranking are shown on 37 maps (in scale 1:250,000), which also show the different elements included and the selected areas. Coast types, logistics and proposed response methods along the coasts are shown on another 37 maps. The sensitivities of the offshore zones are depicted on 4 maps, one for each season. Based on all the information, appropriate oil spill response methods have been assessed for each area. (Author)

  6. On the rms anisotropy at 7 deg and 10 deg observed in the COBE-DMR two year sky maps

    Science.gov (United States)

    Banday, A. J.; Gorski, K. M.; Tenorio, L.; Wright, E. L.; Smoot, G. F.; Lineweaver, C. H.; Kogut, A.; Hinshaw, G.; Bennett, C. L.

    1994-01-01

    The frequency-independent rms temperature fluctuations determined from the Cosmic Background Explorer-Differential Microwave Radiometer (COBE-DMR) two-year sky maps are used to infer the parameter Q(sub rms-PS), which characterizes the normalization of power-law models of primordial cosmological temperature anisotropy, for a forced fit to a scale-invariant Harrison-Zel'dovich (n = 1) spectral model. Using a joint analysis of the 7 deg and 10 deg 'cross'-rms derived from both the 53 and 90 GHz sky maps, we find Q(sub rms-PS) = 17.0(sub -2.1 sup +2.5) micro Kelvin when the low quadrupole is included, and Q(sub rms-PS) = 19.4(sub -2.1 sup +2.3) micro Kelvin excluding the quadrupole. These results are consistent with the n = 1 fits from more sensitive methods. The effect of the low quadrupole derived from the COBE-DMR data on the inferred Q(sub rms-PS) normalization is investigated. A bias to lower Q(sub rms-PS) is found when the quadrupole is included. The higher normalization for a forced n = 1 fit is then favored by the cross-rms technique.

  7. Assessment of zinc finger orientations by residual dipolar coupling constants

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, Vickie; Zhu Leiming; Huang, T.-H.; Wright, Peter E.; Case, David A. [Scripps Research Institute, Department of Molecular Biology (United States)

    2000-01-15

    Residual dipolar coupling constants measured in anisotropic solution contain information on orientations between internuclear vectors and the magnetic field, providing long-range information that may help determine the relative orientations of distinct domains in biomolecules. Here we describe the measurement and use of residual dipolar coupling restraints in the refinement of the structure of the complex of DNA with three zinc fingers of transcription factor IIIA (TFIIIA), measured in a DMPC/DHPC bicelle solution. These dipolar restraints were applied on a variety of orientations of the zinc finger domains (derived from crystallography, previous NMR studies, and systematic modeling) in order to examine the validity and sensitivity of using residual dipolar splittings to study interdomain orientations. The spread in interdomain angles between zinc fingers is reduced from 24 deg. to 9 deg. upon incorporation of dipolar restraints. However, the results also show that the ability to determine relative orientations is strongly dependent on the structural accuracy of the local domain structures.

  8. Fiber biology

    Science.gov (United States)

    Cotton fiber cells arising from seed epidermis is the most important agricultural textile commodity in the world. To produce fully mature fibers, approximately two months of fiber developmental process are required. The timing of four distinctive fiber development stages consisting of initiation, ...

  9. Remodeling of the collagen fiber architecture due to compaction in small vessels under tissue engineered conditions.

    Science.gov (United States)

    Soares, Ana L F; Stekelenburg, Maria; Baaijens, Frank P T

    2011-07-01

    Mechanical loading protocols in tissue engineering (TE) aim to improve the deposition of a properly organized collagen fiber network. In addition to collagen remodeling, these conditioning protocols can result in tissue compaction. Tissue compaction is beneficial to tissue collagen alignment, yet it may lead to a loss of functionality of the TE construct due to changes in geometry after culture. Here, a mathematical model is presented to relate the changes in collagen architecture to the local compaction within a TE small blood vessel, assuming that under static conditions, compaction is the main factor responsible for collagen fiber organization. An existing structurally based model is extended to incorporate volumetric tissue compaction. Subsequently, the model is applied to describe the collagen architecture of TE constructs under either strain based or stress based stimulus functions. Our computations indicate that stress based simulations result in a helical collagen fiber distribution along the vessel wall. The helix pitch angle increases from a circumferential direction in the inner wall, over about 45 deg in the middle vessel layer, to a longitudinal direction in the outer wall. These results are consistent with experimental data from TE small diameter blood vessels. In addition, our results suggest a stress dependent remodeling of the collagen, suggesting that cell traction is responsible for collagen orientation. These findings may be of value to design improved mechanical conditioning protocols to optimize the collagen architecture in engineered tissues.

  10. Dislocation Majorana zero modes in perovskite oxide 2DEG

    Science.gov (United States)

    Chung, Suk Bum; Chan, Cheung; Yao, Hong

    2016-05-01

    Much of the current experimental efforts for detecting Majorana zero modes have been centered on probing the boundary of quantum wires with strong spin-orbit coupling. The same type of Majorana zero mode can also be realized at crystalline dislocations in 2D superconductors with the nontrivial weak topological indices. Unlike at an Abrikosov vortex, at such a dislocation, there is no other low-lying midgap state than the Majorana zero mode so that it avoids usual complications encountered in experimental detections such as scanning tunneling microscope (STM) measurements. We will show that, using the anisotropic dispersion of the t2g orbitals of Ti or Ta atoms, such a weak topological superconductivity can be realized when the surface two-dimensional electronic gas (2DEG) of SrTiO3 or KTaO3 becomes superconducting, which can occur through either intrinsic pairing or proximity to existing s-wave superconductors.

  11. Giant magnetic quadrupole resonance studied with 180 deg. electron scattering

    CERN Document Server

    Neumann-Cosel, P V

    1999-01-01

    The nuclei sup 4 sup 8 Ca and sup 9 sup 0 Zr were investigated in 180 deg. high-resolution inelastic electron scattering for momentum transfers q approx =0.35-0.8 fm sup - sup 1. Complete M2 strength distributions could be extracted in both nuclei up to excitation energies of about 15 MeV utilizing a fluctuation analysis technique. Second-RPA calculations successfully describe the experimentally observed strong fragmentation of the M2 mode. The quenching of the spin part is found to be comparable to the M1 case, contrary to previous claims suggesting a stronger reduction. A quantitative reproduction of the data requires the presence of appreciable orbital strength which can be interpreted as a torsional elastic vibration (the so-called twist mode).

  12. Laicità: finitezza degli ordini e governo delle differenze

    Directory of Open Access Journals (Sweden)

    Nicola Colaianni

    2013-12-01

    Full Text Available Testo della relazione al Convegno Nazionale dell’ADEC sul tema “Per una disciplina che cambia. Il diritto canonico e il diritto ecclesiastico nel tempo presente” (Bologna, 7-9 novembre 2013, destinata alla pubblicazione negli Atti del Convegno. Contributo non sottoposto a valutazioneSOMMARIO: 1. La laicità dei giudici – 2. La laicità dei giuristi – 3. Né regola né valore: un principio – 4. La finitezza degli ordini distinti: dalle materie miste alla sfera dell’indecidibile – 5. L’aconfessionalità sostanziale: a ex parte ecclesiae – 6. (segue: b ex parte status – 7. La laicità come governance delle differenze.

  13. LA FORMAZIONE DEGLI ETNICI NELLA RIFLESSIONE LINGUISTICA DI FRANCESCO CHERUBINI

    Directory of Open Access Journals (Sweden)

    Federica Guerini

    2016-09-01

    Full Text Available Il presente contributo si propone di fornire una descrizione della struttura del Vocabolario Patronimico di Francesco Cherubini e delle fonti empiriche consultate per la sua compilazione. Si accennerà poi a due questioni ricorrenti nel dibattito sulla formazione degli etnici in italiano, ovvero, la presenza di varianti allomorfiche o suppletive, e la motivazione morfo-pragmatica sottesa all’impiego di alcuni suffissi derivativi nella formazione di etnici e aggettivi deonomastici, cercando di chiarire quale attenzione tali tematiche abbiano ricevuto nella riflessione linguistica di Francesco Cherubini. Si formuleranno infine alcune osservazioni conclusive, evidenziando luci ed ombre del Vocabolario Patronimico e sottolineando alcuni degli spunti che tale opera ancora può offrire agli studiosi contemporanei. The formation of ethnic words in Francesco Cherubini’s reflection on language  The aim of this paper is to describe the structure and contents of Francesco Cherubini’s Vocabolario Patronimico, as well as the empirical sources consulted for its compilation. We will address two of the most common issues in the debate on the formation of ethnic nouns and adjectives in Italian, namely the existence of allomorphs and supplementary variants, and the morpho-pragmatic motivation displayed by some of the derivative suffixes occurring in ethnic nouns and adjectives derived from both personal and place names. We will offer a few observations on the place occupied by the above-mentioned issues in Cherubini’s thought and, by analyzing the strengths and weaknesses of the Vocabolario Patronimico, we will draw attention to a few topics which may be of some interest to contemporary scholars.

  14. Numerical simulation of fiber interaction in short-fiber injection-molded composite using different cavity geometries

    Science.gov (United States)

    Thi, Thanh Binh Nguyen; Yokoyama, Atsushi; Hamanaka, Senji; Yamashita, Katsuhisa; Nonomura, Chisato

    2016-03-01

    The theoretical fiber-interaction model for calculating the fiber orientation in the injection molded short fiber/thermoplastic composite parts was proposed. The proposed model included the fiber dynamics simulation in order to obtain an equation of the global interaction coefficient and accurate estimate of the fiber interacts at all orientation states. The steps to derive the equation for this coefficient in short fiber suspension as a function of the fiber aspect ratio, volume fraction and general shear rate are delineated. Simultaneously, the high-resolution 3D X-ray computed tomography system XVA-160α was used to observe fiber distribution of short-glass-fiber-reinforced polyamide specimens using different cavity geometries. The fiber orientation tensor components are then calculated. Experimental orientation measurements of short-glass-fiber-reinforced polyamide is used to check the ability of present theory for predicting orientation. The experiments and predictions show a quantitative agreement and confirm the basic understanding of fiber orientation in injection-molded composites.

  15. Orienteering injuries

    OpenAIRE

    Folan, Jean M.

    1982-01-01

    At the Irish National Orienteering Championships in 1981 a survey of the injuries occurring over the two days of competition was carried out. Of 285 individual competitors there was a percentage injury rate of 5.26%. The article discusses the injuries and aspects of safety in orienteering.

  16. Aligned, short-fiber composites by novel flow processing methods

    Energy Technology Data Exchange (ETDEWEB)

    Guell, D.C.; Graham, A.L.; Papathanasiou, T.; Petrovic, J.J.

    1993-03-01

    A hydrodynamic method has been employed to align short, reinforcing fibers in polymer matrix composite materials. Samples of composite materials were prepared and tested two at a time (one with randomly oriented fibers and the other with aligned fibers) to isolate and directly measure the effect on mechanical properties of aligning the fibers. Data were collected for the ultimate tensile strength, modulus of elasticity, and ultimate tensile strain of the composite samples prepared. Results show that the aligned fibers were approximately twice as effective (as randomly oriented fibers) at stiffening and strengthening the composite in the alignment direction. 5 figs, 20 refs.

  17. Aligned, short-fiber composites by novel flow processing methods

    Energy Technology Data Exchange (ETDEWEB)

    Guell, D.C.; Graham, A.L.; Papathanasiou, T.; Petrovic, J.J.

    1993-01-01

    A hydrodynamic method has been employed to align short, reinforcing fibers in polymer matrix composite materials. Samples of composite materials were prepared and tested two at a time (one with randomly oriented fibers and the other with aligned fibers) to isolate and directly measure the effect on mechanical properties of aligning the fibers. Data were collected for the ultimate tensile strength, modulus of elasticity, and ultimate tensile strain of the composite samples prepared. Results show that the aligned fibers were approximately twice as effective (as randomly oriented fibers) at stiffening and strengthening the composite in the alignment direction. 5 figs, 20 refs.

  18. Catalytic NiO Filter Supported on Carbon Fiber for Oxidation of Volatile Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Jong Ki; Seo, Hyun Ook; Jeong, Myunggeun; Kim, Kwangdae; Kim, Young Dok [Sungkyunkwan Univ., Suwon (Korea, Republic of); Lim, Dong Chan [Korea Institute of Materials Science, Changwon (Korea, Republic of)

    2013-07-15

    Carbon-fiber-supported NiO catalytic filters for oxidation of volatile organic compounds were prepared by electroless Ni-P plating and subsequent annealing processes. Surface structure and crystallinity of NiO film on carbon fiber could be modified by post-annealing at different temperatures (500 and 650 .deg. C). Catalytic thermal decompositions of toluene over these catalytic filters were investigated. 500 .deg. C-annealed sample showed a higher catalytic reactivity toward toluene decomposition than 650 .deg. C-annealed one under same conditions, despite of its lower surface area and toluene adsorption capacity. X-ray diffraction and X-ray photoelectron spectroscopy studies suggest that amorphous structures of NiO on 500 .deg. C-annealed catalyst caused the higher reactivity for oxidation of toluene than that of 650 .deg. C-annealed sample with a higher crystallinity.

  19. Orientation selective deep brain stimulation

    Science.gov (United States)

    Lehto, Lauri J.; Slopsema, Julia P.; Johnson, Matthew D.; Shatillo, Artem; Teplitzky, Benjamin A.; Utecht, Lynn; Adriany, Gregor; Mangia, Silvia; Sierra, Alejandra; Low, Walter C.; Gröhn, Olli; Michaeli, Shalom

    2017-02-01

    Objective. Target selectivity of deep brain stimulation (DBS) therapy is critical, as the precise locus and pattern of the stimulation dictates the degree to which desired treatment responses are achieved and adverse side effects are avoided. There is a clear clinical need to improve DBS technology beyond currently available stimulation steering and shaping approaches. We introduce orientation selective neural stimulation as a concept to increase the specificity of target selection in DBS. Approach. This concept, which involves orienting the electric field along an axonal pathway, was tested in the corpus callosum of the rat brain by freely controlling the direction of the electric field on a plane using a three-electrode bundle, and monitoring the response of the neurons using functional magnetic resonance imaging (fMRI). Computational models were developed to further analyze axonal excitability for varied electric field orientation. Main results. Our results demonstrated that the strongest fMRI response was observed when the electric field was oriented parallel to the axons, while almost no response was detected with the perpendicular orientation of the electric field relative to the primary fiber tract. These results were confirmed by computational models of the experimental paradigm quantifying the activation of radially distributed axons while varying the primary direction of the electric field. Significance. The described strategies identify a new course for selective neuromodulation paradigms in DBS based on axonal fiber orientation.

  20. Orientation and the Young Orienteer

    Science.gov (United States)

    Walsh, S. E.; Martland, J. R.

    Orientation within orienteering is dependent on the use of two basic strategies; that is, either a compass or Magnetic-North-based strategy, which relies on the use of one set of information; or the use of a map and landmark-based strategy which relies on the use of at least two sets of information. Walsh and found that, when given the choice, young children use the compass-based strategy when following complex potentially disorientating routes.The efficacy of these two basic orientation strategies was investigated within three different orienteering environments: (1) a familiar known environment; (2) a familiar unknown environment and (3) an unfamiliar unknown environment.Subjects, age range from 9 to 10think aloud particularly the introduction of basic skills to young performers. They support the argument that is essential to introduce the map and compass simultaneously and that relocation and orientation skills should be coached concurrently.

  1. Compatibility of PIP SiC{sub f}/SiC with LiPb at 700 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Shuang, E-mail: zhsh6007@126.com [Key Laboratory of Advanced Ceramic Fibers and Composites, National University of Defense Technology, Changsha (China); Zhou Xingui; Yu Haijiao; Wang Honglei [Key Laboratory of Advanced Ceramic Fibers and Composites, National University of Defense Technology, Changsha (China); Wu Yican; Huang Qunying; Zhu Zhiqiang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Huang Zelan [Chongyi Zhangyuan Tungsten Co. Ltd., Chongyi (China)

    2010-12-15

    Silicon carbide fiber reinforced silicon carbide composites (SiC{sub f}/SiC) are promising candidate materials for fusion applications. The compatibility of SiC{sub f}/SiC composites with liquid LiPb is one of the key issues for fusion technologies. Three-dimensional SiC{sub f}/SiC composites were fabricated by polymer infiltration and pyrolysis (PIP) process and {beta}-SiC coating was deposited by chemical vapor deposition (CVD) process. The composites were exposed to static liquid LiPb for 500 h at 700 deg. C. The results showed that the liquid LiPb penetrated through the open pores of the cut surface of the composites and reacted with the matrix and fibers, which caused a weight change and a severe degradation of the mechanical property to the uncoated composites. As for the coated composites, the mechanical property was degraded and the weight increased because of the absorption of LiPb, although the CVD SiC coating was compatible with LiPb and protected fibers and matrix beneath.

  2. NUMERICAL SIMULATION ON VELOCITIES OF TWO INTERACTING FIBERS IN FIBER SUSPENSION

    Institute of Scientific and Technical Information of China (English)

    Lin Jian-zhong; Bao Fu-bing; Zhang Zhi-chao

    2003-01-01

    A mathematical model was put forward to describe the mechanical interactions of two contacting fibers, then a numerical simulation was carried out.The results of the simulation accord with experimental results well.It turns out that the initial contacting point and the initial orientation of the settling fiber have much effect on the translational and rotational velocities of the settling fiber, along with the increase in the length or the decrease in the radius of the fiber, the translational and rotational velocities of the settling fiber decrease; the same trend remains when the viscosity of the solvent increases or the density of the fiber decreases.

  3. Optical-Fiber Fluorosensors With Polarized Light Sources

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1995-01-01

    Chemiluminescent and/or fluorescent molecules in optical-fiber fluorosensors oriented with light-emitting dipoles along transverse axis. Sensor of proposed type captures greater fraction of chemiluminescence or fluorescence and transmits it to photodetector. Transverse polarization increases sensitivity. Basic principles of optical-fiber fluorosensors described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525), "Improved Optical-Fiber Chemical Sensors" (LAR-14607), and "Improved Optical-Fiber Temperature Sensors" (LAR-14647).

  4. Optical-Fiber Fluorosensors With Polarized Light Sources

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1995-01-01

    Chemiluminescent and/or fluorescent molecules in optical-fiber fluorosensors oriented with light-emitting dipoles along transverse axis. Sensor of proposed type captures greater fraction of chemiluminescence or fluorescence and transmits it to photodetector. Transverse polarization increases sensitivity. Basic principles of optical-fiber fluorosensors described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525), "Improved Optical-Fiber Chemical Sensors" (LAR-14607), and "Improved Optical-Fiber Temperature Sensors" (LAR-14647).

  5. A 360-deg Digital Image Correlation system for materials testing

    Science.gov (United States)

    Genovese, K.; Cortese, L.; Rossi, M.; Amodio, D.

    2016-07-01

    The increasing research interest toward natural and advanced engineered materials demands new experimental protocols capable of retrieving highly dense sets of experimental data on the full-surface of samples under multiple loading conditions. Such information, in fact, would allow to capture the possible heterogeneity and anisotropy of the material by using up-to-date inverse characterization methods. Although the development of object-specific test protocols could represent the optimal choice to address this need, it is unquestionable that universal testing machines (UTM) remain the most widespread and versatile option to test materials and components in both academic and industrial contexts. A major limitation of performing standard material tests with UTM, however, consists in the scarce information obtainable with the commonly associated sensors since they provide only global (LVDTs, extensometers, 2D-video analyzers) or local (strain gages) measures of displacement and strain. This paper presents a 3D Digital Image Correlation (DIC) system developed to perform highly accurate full-surface 360-deg measurements on either standard or custom-shaped samples under complex loading within universal testing machines. To this aim, a low cost and easy to setup video rig was specifically designed to overcome the practical limitations entailed with the integration of a multi-camera system within an already existing loading frame. In particular, the proposed system features a single SLR digital camera moved through multiple positions around the specimen by means of a large rotation stage. A proper calibration and data-processing procedure allows to automatically merge the experimental data obtained from the multiple views with an accuracy of 10-2 m m . The results of a full benchmarking of the metrological performances of the system are here reported and discussed together with illustrative examples of full-360-deg shape and deformation measurements on a Grade X65 steel

  6. Readout of a scintillating-fiber array by avalanche photodiodes

    CERN Document Server

    Okusawa, T; Yamasaki, M; Yoshida, T

    2000-01-01

    We have evaluated the performance of avalanche photodiodes (APDs) as photosensors for scintillating-fiber tracking detectors, putting emphasis on their temperature dependence. For this purpose, a scintillating-fiber array has been built with 0.5 mm diameter fibers 55 cm long. The array is so structured that an incident particle traverses two fibers coupled to an APD. As temperature of the APD falls, the signal-to-noise (S/N) ratio rises exponentially. It even reaches 90 at -30 deg. C. The detection efficiency exceeds 98% when the temperature decreases until the S/N ratio becomes 30.

  7. Electrospun ceramic fibers: Composition, structure and the fate of precursors

    Energy Technology Data Exchange (ETDEWEB)

    Tuttle, R.W.; Chowdury, A. [Department of Physics, Ayer Hall, 302 Buchtel Common, University of Akron, Akron, OH 44325-4001 (United States); Bender, E.T. [Department of Chemistry, Knight Chemical Laboratory, 302 Buchtel Common, University of Akron, Akron, OH 44325-3601 (United States); Ramsier, R.D. [Department of Physics, Ayer Hall, 302 Buchtel Common, University of Akron, Akron, OH 44325-4001 (United States); Department of Chemistry, Knight Chemical Laboratory, 302 Buchtel Common, University of Akron, Akron, OH 44325-3601 (United States); Institute for Teaching and Learning, Leigh Hall, 302 Buchtel Common, University of Akron, Akron, OH 44325-6236 (United States)], E-mail: rex@uakron.edu; Rapp, J.L.; Espe, M.P. [Department of Chemistry, Knight Chemical Laboratory, 302 Buchtel Common, University of Akron, Akron, OH 44325-3601 (United States)

    2008-06-15

    Fibers are electrospun from aluminum acetate/polymer mixtures and characterized by an array of techniques before and after annealing at 1200 deg.C. We demonstrate that sodium and boron present in the initial starting materials as adducts and stabilizers remain incorporated into the resulting fibers after annealing and pyrolysis of the host polymer. The influence of these minor constituents on the surfaces of the fibers is suggested by infrared and X-ray photoelectron spectroscopic data. The presence of these species may impact potential chemical applications of small diameter ceramic fibers, such as their use as catalytic supports or for chemical decomposition.

  8. Analyzing Orientations

    Science.gov (United States)

    Ruggles, Clive L. N.

    Archaeoastronomical field survey typically involves the measurement of structural orientations (i.e., orientations along and between built structures) in relation to the visible landscape and particularly the surrounding horizon. This chapter focuses on the process of analyzing the astronomical potential of oriented structures, whether in the field or as a desktop appraisal, with the aim of establishing the archaeoastronomical "facts". It does not address questions of data selection (see instead Chap. 25, "Best Practice for Evaluating the Astronomical Significance of Archaeological Sites", 10.1007/978-1-4614-6141-8_25) or interpretation (see Chap. 24, "Nature and Analysis of Material Evidence Relevant to Archaeoastronomy", 10.1007/978-1-4614-6141-8_22). The main necessity is to determine the azimuth, horizon altitude, and declination in the direction "indicated" by any structural orientation. Normally, there are a range of possibilities, reflecting the various errors and uncertainties in estimating the intended (or, at least, the constructed) orientation, and in more formal approaches an attempt is made to assign a probability distribution extending over a spread of declinations. These probability distributions can then be cumulated in order to visualize and analyze the combined data from several orientations, so as to identify any consistent astronomical associations that can then be correlated with the declinations of particular astronomical objects or phenomena at any era in the past. The whole process raises various procedural and methodological issues and does not proceed in isolation from the consideration of corroborative data, which is essential in order to develop viable cultural interpretations.

  9. COSMOS Photometric Redshifts with 30-bands for 2-deg2

    CERN Document Server

    Ilbert, O; Salvato, M; Aussel, H; McCracken, H J; Sanders, D B; Scoville, N; Kartaltepe, J; Arnouts, S; Le Floc'h, E; Mobasher, B; Taniguchi, Y; Lamareille, F; Leauthaud, A; Sasaki, S; Thompson, D; Zamojski, M; Zamorani, G; Bardelli, S; Bolzonella, M; Bongiorno, A; Brusa, M; Caputi, K I; Carollo, C M; Contini, T; Cook, R; Coppa, G; Cucciati, O; De la Torre, S; de Ravel, L; Franzetti, P; Garilli, B; Hasinger, G; Iovino, A; Kampczyk, P; Kneib, J -P; Knobel, C; Kovac, K; Le Borgne, J F; Le Brun, V; Le Fèvre, O; Lilly, S; Looper, D; Maier, C; Mainieri, V; Mellier, Y; Mignoli, M; Murayama, T; Pellò, R; Peng, Y; Pérez-Montero, E; Renzini, A; Ricciardelli, E; Schiminovich, D; Scodeggio, M; Shioya, Y; Silverman, Joseph; Surace, J; Tanaka, M; Tasca, L; Tresse, L; Vergani, D; Zucca, E

    2008-01-01

    We present accurate photometric redshifts in the 2-deg2 COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrow bands covering the UV (GALEX), Visible-NIR (Subaru, CFHT, UKIRT and NOAO) and mid-IR (Spitzer/IRAC). A chi2 template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from VLT-VIMOS and Keck-DEIMOS. We develop and implement a new method which accounts for the contributions from emission lines (OII, Hbeta, Halpha and Ly) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e. Delta z = zs - zp) indicates a dispersion of sigma_{Delta z/(1+zs)}=0.007 at i<22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHTLS and COMBO-17 survey fields. At fainter magnitudes i<24 and z<1.25, the accuracy is sigma_{Delta z/(1+zs)}=0.012. The deep NIR and IRAC coverage enables the ph...

  10. LE ZANZARE ITALIANE: GENERALITÀ E IDENTIFICAZIONE DEGLI ADULTI (DIPTERA, CULICIDAE

    Directory of Open Access Journals (Sweden)

    Francesco Severini

    2009-12-01

    Full Text Available Nel presente lavoro vengono riportate le informazioni essenziali su tassonomia e biologia nonché sugli aspetti ecologici degli adulti dei Culicidi italiani. Attualmente la fauna culicidica italiana comprende 64 specie appartenenti a 2 sottofamiglie e 8 generi. Alla sottofamiglia Anophelinae appartiene soltanto il genere Anopheles, presente con 16 specie raggruppate in due sottogeneri. Alla sottofamiglia Culicinae appartengono i rimanenti 7 generi: Aedes con 6 specie raggruppate in 3 sottogeneri, Coquillettidia con 2 specie, Ochlerotatus con 20 specie raggruppate in 3 sottogeneri, Culex con 12 specie raggruppate in 4 sottogeneri, Culiseta con 6 specie raggruppate in 3 sottogeneri, Orthopodomyia e Uranotaenia con una specie ognuna. In questo contesto vengono fornite le chiavi di identificazione specifica per le zanzare adulte, in italiano e in inglese. Le chiavi sono corredate da un’ampia iconografia (figure 1-75. Alle chiavi fa seguito la diagnosi morfologica dell’adulto di ogni specie con note sulla relativa biologia e distribuzione. Per ulteriori approfondimenti viene riportata la bibliografia completa sulle zanzare della fauna italiana dal 1960 ed i precedenti lavori più autorevoli.

  11. Come e cosa desidera la narrativa italiana degli anni Zero

    Directory of Open Access Journals (Sweden)

    Gianluigi Simonetti

    2013-05-01

    Full Text Available L'articolo analizza il trattamento del tema del desiderio - erotico e amoroso - nel romanzo italiano degli ultimi anni, impegnandosi nell'esame ravvicinato di alcuni testi esemplari. La campionatura vuole da un lato isolare alcune opere rappresentative della situazione attuale della narrativa contemporanea, dall'altro  proporre un'ipotesi categoriale che seziona il campo di studio in tre parti; il sondaggio sembra infatti suggerire che le dinamiche del desiderio vengono rese in maniera specifica nei diversi ambiti della letteratura di consumo, in quella di 'nobile intrattenimento' e in quella 'forte' e letterariamente più ambiziosa. L'analisi formale risulta insomma integrata a una prospettiva di stroria dello stile, secondo un metodo che permette di utilizzare la figuralità letteraria come 'indicatore sociologico' di processi politici (e forse antropologici in atto.

  12. Le caratteristiche degli acquirenti e venditori di abitazioni

    Directory of Open Access Journals (Sweden)

    Erika Ghiraldo

    2011-12-01

    Full Text Available L’incrocio dei dati contenuti nelle dichiarazioni dei redditi con quelli contenuti negli archivi della Pubblicità Immobiliare (ex Conservatorie rende disponibili molte informazioni sulle caratteristiche dei contraenti che hanno effettuato una compravendita di unità immobiliari. Considerando principalmente le compravendite di unità immobiliari del settore residenziale effettuate da persone fisiche sono trattate informazioni sul reddito dichiarato al fisco, l’età e l’attività di lavoro prevalente. È fornito un quadro sintetico della distribuzione delle compravendite, in termini di Numero di Transazioni Normalizzate (NTN e per dimensione delle abitazioni, per ciascuna caratteristica sia per gli acquirenti che per i venditori. La disponibilità dell’informazione sulla residenza dei soggetti consente, inoltre, di condurre un’analisi sulla provenienza degli acquirenti rispetto al luogo di ubicazione dell’immobile compravenduto. E’ possibile così analizzare la composizione del mercato distinguendo la quota di acquisti imputabile a soggetti residenti nello stesso Comune di ubicazione dell’immobile (mercato comunale dalla quota alimentata da soggetti residenti in altro Comune di una stessa provincia (mercato infraprovinciale o di altra provincia (mercato extra-provinciale. Quest’ultima indagine risulta molto interessante se effettuata su singole città. Sono, quindi, riportati i risultati dell’analisi per i mercati delle città di Milano, Roma e Napoli.

  13. Dietary Fiber

    Science.gov (United States)

    Fiber is a substance in plants. Dietary fiber is the kind you eat. It's a type of carbohydrate. You may also see it listed on a food label as soluble ... types have important health benefits. Good sources of dietary fiber include Whole grains Nuts and seeds Fruit and ...

  14. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including t...

  15. Investigation of silicon Avalanche Photodiodes for use in scintillating fiber trackers

    CERN Document Server

    Bähr, J; Kantserov, V A; Kell, G; Nahnhauer, R

    2000-01-01

    The readout of scintillating fibers using Silicon APDs and Metal-Resistive-Semiconductor (MRS) devices was investigated in a large temperature range down to -150 deg. C in the laboratory and at an electron beam. In comparison to conventional PMs with bialkali cathodes an improved efficiency was found for low light signals from blue and green scintillating fibers of 0.5 mm diameter.

  16. The BLAST View of the Star Forming Region in Aquila (ell=45deg,b=0deg)

    CERN Document Server

    Rivera-Ingraham, Alana; Bock, James J; Chapin, Edward L; Devlin, Mark J; Dicker, Simon R; Griffin, Matthew; Gundersen, Joshua O; Halpern, Mark; Hargrave, Peter C; Hughes, David H; Klein, Jeff; Marsden, Gaelen; Martin, Peter G; Mauskopf, Philip; Netterfield, Calvin B; Olmi, Luca; Patanchon, Guillaume; Rex, Marie; Scott, Douglas; Semisch, Christopher; Truch, Matthew D P; Tucker, Carole; Tucker, Gregory S; Viero, Marco P; Wiebe, Donald V

    2010-01-01

    We have carried out the first general submillimeter analysis of the field towards GRSMC 45.46+0.05, a massive star forming region in Aquila. The deconvolved 6 deg^2 (3\\degree X 2\\degree) maps provided by BLAST in 2005 at 250, 350, and 500 micron were used to perform a preliminary characterization of the clump population previously investigated in the infrared, radio, and molecular maps. Interferometric CORNISH data at 4.8 GHz have also been used to characterize the Ultracompact HII regions (UCHIIRs) within the main clumps. By means of the BLAST maps we have produced an initial census of the submillimeter structures that will be observed by Herschel, several of which are known Infrared Dark Clouds (IRDCs). Our spectral energy distributions of the main clumps in the field, located at ~7 kpc, reveal an active population with temperatures of T~35-40 K and masses of ~10^3 Msun for a dust emissivity index beta=1.5. The clump evolutionary stages range from evolved sources, with extended HII regions and prominent IR ...

  17. Il disagio degli insegnanti tra psicologia e pedagogia: una indagine multidimensionale sul fenomeno del burnout

    Directory of Open Access Journals (Sweden)

    Francesca Botticelli

    2012-06-01

    strumento politico. Le soluzioni proposte devono configurarsi nella direzione di azioni specifiche orientate alla formazione degli insegnanti di scuola superiore che privilegi strategie di empowerment volte al fronteggiamento di inevitabili frustrazioni e delusioni lavorative, alla formazione di una dirigenza in grado di esercitare forme di leadership promozionale; una formazione al saper essere a tutti i livelli della scuola e per tutto il personale e infine la promozione di una ricerca di significato che costituisce la base di un vero benessere all‘interno della scuola che rimane, nelle dinamiche che si intrecciano all‘interno di essa e nella sua configurazione sistemica, un microcosmo sociale.

  18. A Compact Fiber Inclinometer Using a Thin-Core Fiber with Incorporated an Air-Gap Microcavity Fiber Interferometer

    Directory of Open Access Journals (Sweden)

    Jiacheng Li

    2016-01-01

    Full Text Available A compact fiber-optic inclinometer is proposed and experimentally demonstrated based on a Fabry-Perot interference (FFPI. The sensing head consists of a short segment of thin-core fiber (TCF following with a piece of hollow-core fiber (HCF. High-order cladding modes have been excited because of core diameter mismatch. A clear interference spectrum has been obtained as the consequence of interference among the reflected core modes and cladding modes. Fringe contrast of the interference spectrum is highly sensitive to fiber bending with direction independence, and good linearity has been observed during the bending range from 1° to 3° with a sensitivity of 2.71 dB/deg.

  19. Water Fibers

    CERN Document Server

    Douvidzon, Mark L; Martin, Leopoldo L; Carmon, Tal

    2016-01-01

    Fibers constitute the backbone of modern communication and are used in laser surgeries; fibers also genarate coherent X-ray, guided-sound and supercontinuum. In contrast, fibers for capillary oscillations, which are unique to liquids, were rarely considered in optofluidics. Here we fabricate fibers by water bridging an optical tapered-coupler to a microlensed coupler. Our water fibers are held in air and their length can be longer than a millimeter. These hybrid fibers co-confine two important oscillations in nature: capillary- and electromagnetic-. We optically record vibrations in the water fiber, including an audio-rate fundamental and its 3 overtones in a harmonic series, that one can hear in soundtracks attached. Transforming Micro-Electro-Mechanical-Systems [MEMS] to Micro-Electro-Capillary-Systems [MECS], boosts the device softness by a million to accordingly improve its response to minute forces. Furthermore, MECS are compatible with water, which is a most important liquid in our world.

  20. Pressure Loss Through Sharp 180 deg Turn in a Relatively Short Two-Pass Smooth and RibRoughened Channel

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    The local pressure distributions and resistance coefficients(f1 and f2) through the sharp 180 deg turn in a relatively short (L/De=4) two-pass smooth and rib-roughened channel were investigated for a Reynolds number range of 1.0×103,9.0×103.The rib pitch-to-herght ratios(p/e) were 5,10,and 20,The rib height-to-hydraulic diamter ratios(e/De) were 0.025,0.050 and 0.10,and the rib angles of attack(a) were 90,45,60,-45,and -60 deg.Rids were installed not only in before and after turn regions but also in turn region.The results show that resistance coefficients remain approximately constant when Reynolds number is more than 3.0×104,The effects of the rib configuration(rib spacing,rib height,and rib orientation)on the inlet straight duct resistance coefficient(f2) were significant, however,their effects on the overall resistance coefficient(f1) were diluted by the sharp-180 turn.For this relatively short channel(L/De=4),the overall resistance coefficient(f1) was greatly affected by the sharp turn.Correlations for the overall resistance(f1) and inlet straight duct resistance coefficient (f2) are presented.

  1. Multiplex and simultaneous measurement of displacement and temperature using tapered fiber and fiber Bragg grating

    Energy Technology Data Exchange (ETDEWEB)

    Ji Chongke; Zhao Chunliu; Kang Juan; Dong Xinyong; Jin Shangzhong [Institute of Optoelectronic Technology, China Jiliang University, Hangzhou 310018 (China)

    2012-05-15

    A simple method to work out the multiplexing of tapered fiber based sensors is proposed and demonstrated. By cascading a tapered fiber with a fiber Bragg grating (FBG), the sensor head is provided with a wavelength identification, different FBGs provide the sensor heads with different reflective peaks and they can be distinguished in optical spectrum. By compositing several such sensor heads with a multi-channel beam splitter, a star-style topological structure sensor for multipoint sensing is achieved. At the same time, the output intensity at the peak wavelength is sensitive to one external physical parameter applied on the related FBG-cascaded tapered fiber and the central wavelength of the peak is only sensitive to temperature, so that that parameter and temperature can be measured simultaneously. A sensor for dual-point measurement of the displacement and temperature simultaneously is experimentally demonstrated by using a 2 x 2 coupler in this paper. Experiment results show that the sensor works well and the largest sensitivities reach to 0.11 dB/{mu}m for displacement in the range of 0-400 {mu}m, and {approx}0.0097 nm/ deg. C for temperature between 20 deg. C and 70 deg. C.

  2. Orienteering club

    CERN Document Server

    Club d'orientation

    2015-01-01

    Course d'orientation La reprise des courses d’orientation était attendue dans la région puisque près de 150 coureurs ont participé à la première épreuve automnale organisée par le club d’orientation du CERN sur le site de La Faucille. Les circuits ont été remportés par Yann Locatelli du club d’Orientation Coeur de Savoie avec 56 secondes d’avance sur Damien Berguerre du club SOS Sallanches pour le parcours technique long, Marie Vuitton du club CO CERN (membre également de l’Equipe de France Jeune) pour le parcours technique moyen avec presque 4 minutes d’avance sur Jeremy Wichoud du club Lausanne-Jorat, Victor Dannecker pour le circuit technique court devant Alina Niggli, Elliot Dannecker pour le facile moyen et Alice Merat sur le facile court, tous membres du club O’Jura. Les résultats comp...

  3. Photoluminescence of a High Mobility 2DEG in the Fractional Quantum Hall Effect Regime

    Science.gov (United States)

    Smirnov, D.; Rudenkov, V. V.; Ashkinadze, B. M.; Cohen, E.; Christianen, P. C. M.; Maan, J. C.; Pfeiffer, L. N.

    The magneto-PL spectra of modulation-doped, ultra-high mobility GaAs/AlGaAs single heterojunctions (HJs) were studied under a perpendicularly applied magnetic field up to 33 T and at temperatures of 0.3 and 1.2 K. The spectra show remarkable intensity redistribution between free (bulk) exciton and 2DEG-hole PL channels occurring at electron filling factors, ν = 2 and 1. At 0.3 K, significant 2DEG-hole PL spectral changes are observed near ν = 2/3 and 1/3. Several heterojunctions with 2DEG density in the range of n2D - (1 - 2.7) · 1011 cm-2 display similar features. These spectral peculiarities are attributed to the modification of the 2DEG energy spectrum caused by the e-e interaction, in particular, the recombination of valence hole with the composite (fractionally-charged) particles of the magnetized 2DEG. In HJs with lower n2D < 1011 cm-2, the observed PL evolution at ν < 1 is mainly determined by an intensity redistribution between the σ+ and σ- circularly-polarized free exciton PL components. In this case, the exciton energy is lower than the energy of the 2DEG-hole system, so that the free excitons do not dissociate near the magnetized 2DEG and thus, the 2DEG-hole PL is barely observed.

  4. Preparation and characterization of boron nitride coatings on carbon fibers from borazine by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Li Junsheng, E-mail: charlesljs@163.com [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha, 410073 (China); Zhang Changrui; Li Bin [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha, 410073 (China)

    2011-06-15

    Boron nitride (BN) coatings were deposited on carbon fibers by chemical vapor deposition (CVD) using borazine as single source precursor. The deposited coatings were characterized by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The effect of temperatures on growth kinetics, morphology, composition and structure of the coatings was investigated. In the low temperature range of 900 deg. C-1000 deg. C, the growth rate increased with increasing temperature complying with Arrhenius law, and an apparent active energy of 72 kJ/mol was calculated. The coating surface was smooth and compact, and the coatings uniformly deposited on individual fibers of carbon fiber bundles. The growth was controlled by surface reaction. At 1000 deg. C, the deposition rate reached a maximum (2.5 {mu}m/h). At the same time, the limiting step of the growth translated to be mass-transportation. Above 1100 deg. C, the growth rate decreased drastically due to the occurrence of gas-phase nucleation. Moreover, the coating surface became loose and rough. Composition and structure examinations revealed that stoichiometric BN coatings with turbostratic structure were obtained below 1000 deg. C, while hexagonal BN coatings were deposited above 1100 deg. C. A penetration of carbon element from the fibers to the coatings was observed.

  5. Accelerated transformation of brushite to octacalcium phosphate in new biomineralization media between 36.5 deg. C and 80 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Temizel, Neslihan; Girisken, Giray; Tas, A. Cuneyt, E-mail: cuneyt-tas@ouhsc.edu

    2011-07-20

    This study investigated the hydrothermal transformation of brushite (dicalcium phosphate dihydrate, DCPD, CaHPO{sub 4}.2H{sub 2}O) into octacalcium phosphate (OCP, Ca{sub 8}(HPO{sub 4}){sub 2}(PO{sub 4}){sub 4}.5H{sub 2}O) in seven different newly developed biomineralization media, all inspired from the commercial DMEM solutions, over the temperature range of 36.5 deg. C to 90 deg. C with aging times varying between 1 h and 6 days. DCPD powders used in this study were synthesized in our laboratory by using a wet-chemical technique. DCPD was found to transform into OCP in the Ca{sup 2+}, Mg{sup 2+}, Na{sup +}, K{sup +}, HCO{sub 3}{sup -}, Cl{sup -} and H{sub 2}PO{sub 4}{sup -} containing aqueous biomineralization media in less than 72 h at 36.5 deg. C, without stirring. The same medium was able to convert DCPD into OCP in about 2 h at 75-80 deg. C, again without a need for stirring. Samples were characterized by using powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). - Research highlights: {yields} New biomineralization solutions developed to convert DCPD into OCP at 36.5 deg. C to 80 deg. C. {yields} DCPD powder was the starting material. {yields} OCP was synthesized under static conditions (no need for stirring). {yields} OCP was synthesized in sealed glass media bottles in solutions free of Hepes or Tris. {yields} OCP can be synthesized at 75-80 deg. C in only 2 hours in the above solutions without stirring.

  6. AtDeg2 – a chloroplast protein with dual protease/chaperone activity

    Directory of Open Access Journals (Sweden)

    Przemysław Jagodzik

    2014-07-01

    Full Text Available Chloroplast protease AtDeg2 (an ATP-independent serine endopeptidase is cytosolically synthesized as a precursor, which is imported into the chloroplast stroma and deprived of its transit peptide. Then the mature protein undergoes routing to its functional location at the stromal side of thylakoid membrane. In its linear structure AtDeg2 molecule contains the protease domain with catalytic triad (HDS and two PDZ domains (PDZ1 and PDZ2. In vivo AtDeg2 most probably exists as a supposedly inactive haxamer, which may change its oligomeric stage to form active 12-mer, or 24-mer. AtDeg2 has recently been demonstrated to exhibit dual protease/chaperone function. This review is focused on the current awareness with regard to AtDeg2 structure and functional significance.

  7. Patologie sociali, resistenze e difese degli insegnanti nell’istituzione scolastica: Considerazioni cliniche e pedagogiche

    Directory of Open Access Journals (Sweden)

    Tommaso Fratini

    2014-12-01

    Full Text Available L’articolo prende in esame il tema di alcune resistenze e difese degli insegnanti all’interno dell’istituzione scolastica. Partendo dall’attuale condizione di emergenza della scuola italiana e rifacendosi al concetto di patologia sociale di Giuseppe Di Chiara, viene argomentato come tali resistenze coprano le angosce persecutorie degli insegnanti nel loro lavoro scolastico quotidiano nel rapporto con gli allievi. L’articolo, tra le varie forme di patologia istituzionale, affronta principalmente il tema di quelle che presiedono alle resistenze degli insegnanti al lavoro introspettivo con il proprio mondo interno, conseguenza e ulteriore cagione di sensi di colpa nel rapporto con gli allievi e di fenomeni di burnout lavorativo degli stessi insegnanti. Tali fenomeni vanno nella direzione del rinforzo sia di un atteggiamento di chiusura verso la collaborazione con professionisti esterni all’istituzione scolastica, sia di un atteggiamento di minore empatia e vicinanza emotiva con la realtà interna degli allievi.

  8. Sexual Orientation (For Parents)

    Science.gov (United States)

    ... Teaching Kids to Be Smart About Social Media Sexual Orientation KidsHealth > For Parents > Sexual Orientation Print A ... orientation is part of that process. What Is Sexual Orientation? The term sexual orientation refers to the ...

  9. Temperature dependent dynamics of DegP-trimer: A molecular dynamics study.

    Science.gov (United States)

    Rai, Nivedita; Ramaswamy, Amutha

    2015-01-01

    DegP is a heat shock protein from high temperature requirement protease A family, which reacts to the environmental stress conditions in an ATP independent way. The objective of the present analysis emerged from the temperature dependent functional diversity of DegP between chaperonic and protease activities at temperatures below and above 28 °C, respectively. DegP is a multimeric protein and the minimal functional unit, DegP-trimer, is of great importance in understanding the DegP pathway. The structural aspects of DegP-trimer with respect to temperature variation have been studied using molecular dynamics simulations (for 100 ns) and principal component analysis to highlight the temperature dependent dynamics facilitating its functional diversity. The DegP-trimer revealed a pronounced dynamics at both 280 and 320 K, when compared to the dynamics observed at 300 K. The LA loop is identified as the highly flexible region during dynamics and at extreme temperatures, the residues 46-80 of LA loop express a flip towards right (at 280) and left ( at 320 K) with respect to the fixed β-sheet connecting the LA loop of protease for which Phe46 acts as one of the key residues. Such dynamics of LA loop facilitates inter-monomeric interaction with the PDZ1 domain of the neighbouring monomer and explains its active participation when DegP exists as trimer. Hence, the LA loop mediated dynamics of DegP-trimer is expected to provide further insight into the temperature dependent dynamics of DegP towards the understanding of its assembly and functional diversity in the presence of substrate.

  10. Temperature dependent dynamics of DegP-trimer: A molecular dynamics study

    Directory of Open Access Journals (Sweden)

    Nivedita Rai

    2015-01-01

    Full Text Available DegP is a heat shock protein from high temperature requirement protease A family, which reacts to the environmental stress conditions in an ATP independent way. The objective of the present analysis emerged from the temperature dependent functional diversity of DegP between chaperonic and protease activities at temperatures below and above 28 °C, respectively. DegP is a multimeric protein and the minimal functional unit, DegP-trimer, is of great importance in understanding the DegP pathway. The structural aspects of DegP-trimer with respect to temperature variation have been studied using molecular dynamics simulations (for 100 ns and principal component analysis to highlight the temperature dependent dynamics facilitating its functional diversity. The DegP-trimer revealed a pronounced dynamics at both 280 and 320 K, when compared to the dynamics observed at 300 K. The LA loop is identified as the highly flexible region during dynamics and at extreme temperatures, the residues 46–80 of LA loop express a flip towards right (at 280 and left ( at 320 K with respect to the fixed β-sheet connecting the LA loop of protease for which Phe46 acts as one of the key residues. Such dynamics of LA loop facilitates inter-monomeric interaction with the PDZ1 domain of the neighbouring monomer and explains its active participation when DegP exists as trimer. Hence, the LA loop mediated dynamics of DegP-trimer is expected to provide further insight into the temperature dependent dynamics of DegP towards the understanding of its assembly and functional diversity in the presence of substrate.

  11. Effect of annealing prior to cold rolling on magnetic and mechanical properties of low carbon non-oriented electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Castaneda, E.J., E-mail: emmanuel.gutierrez@yahoo.com.mx [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (CINVESTAV-IPN), Department of Metallurgical Engineering and Materials Science, Carretera Saltillo-Monterrey, Km 13.5, 25900 Ramos Arizpe, Coahuila, P.O. Box 663, Saltillo Coahuila, 25000 (Mexico); Salinas-Rodriguez, A., E-mail: armando.salinas@cinvestav.edu.mx [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (CINVESTAV-IPN), Department of Metallurgical Engineering and Materials Science, Carretera Saltillo-Monterrey, Km 13.5, 25900 Ramos Arizpe, Coahuila, P.O. Box 663, Saltillo Coahuila, 25000 (Mexico)

    2011-10-15

    The effects of annealing prior to cold rolling on the microstructure, magnetic and mechanical properties of low-C grain non-oriented (GNO) electrical steels have been investigated. The grain structure of hot-rolled electrical steel strips is modified by annealing at temperatures between 700 and 1050 deg. C. Annealing at temperatures less than the ferrite to austenite+ferrite transformation temperature on heating (Ac{sub 1}) causes a marginal effect on the grain size. However, annealing in the intercritical region at temperatures between Ac{sub 1} and Ac{sub 3} (the ferrite+austenite to austenite transformation temperature on heating) causes rapid decarburization and development of large columnar ferrite grains free of carbide particles. This microstructure leads, after cold rolling and a fast annealing treatment, to carbide free, large ferrite grain microstructures with magnetic and mechanical properties superior to those observed typically in the same steel in the industrially fully processed condition. These results are attributed to the increment in grain size and to the {l_brace}1 0 0{r_brace} fiber texture developed during the final annealing at temperatures up to 850 deg. C. Annealing at higher temperatures, T>Ac{sub 3}, results in a strong {l_brace}1 1 1{r_brace} fiber texture and an increase of the quantity of second phase particles present in the microstructure, which lead to a negative effect on the final properties. The results suggest that annealing prior to cold rolling offers an attractive alternative processing route for the manufacture of fully processed low C GNO electrical steels strips. - Highlights: > Electrical steels are produced by an alternative processing route. > Annealing of the hot rolled electrical steel strips causes rapid decarburization. > Development of the <1 0 0>//ND texture results in better magnetic properties. > Magnetic properties of electrical steels depend on the grain size and texture. > Second phase particles and grain

  12. Stability in channel flow with fiber suspensions

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The constitutive equation of fiber suspensions is established on the basis of fiber orientation tensors. The modified Orr-Sommerfeld stability equation is obtained further and numerically solved by aid of spectral method and finite difference method. The computational results of channel flow without fibers agree well with the experimental data with a higher degree of accuracy than previous numerical results. The results of the channel flow with fiber suspensions indicate that the presence of fibers attenuates the instability of flow, increases the critical Reynolds number, reduces the growth rate of perturbations and narrows the range of unstable waves. The extent of the effect of fibers on the flow stability is in direct proportion to the volume fraction and aspect-ratio of the fibers.

  13. Orienteering Club

    CERN Document Server

    Club d'orientation

    2013-01-01

    Courses d’orientation Une bonne dizaine de clubs étaient représentés samedi dernier à La Faucille pour participer à la  2e manche de la coupe genevoise organisée par le club du CERN. Les 120 coureurs ont pu découvrir des parcours classés "technique". Ceux du Haut-Jura familiarisés à ce type de terrain ont pu sortir leur épingle du jeu et se sont octroyé la victoire sur 4 des 5 circuits. Samedi 21 septembre, la montagne du Haut-Jura était encore plébiscitée puisque les coureurs étaient attendus à Saint Cergue sur la carte des Pralies. Pour les résultats complets de La Faucille et les informations sur la prochaine étape, consultez le site du club http://cern.ch/club-orientation.

  14. Orientation Club

    CERN Multimedia

    Club d'orientation

    2014-01-01

    COURSE ORIENTATION Résultats de samedi 10 mai    C’est sur une carte entièrement réactualisée dans les bois de Versoix, que plus de 100 coureurs sont venus participer à la course d’orientation, type longue distance, préparée par des membres du club du CERN. Le terrain plutôt plat nécessitait une orientation à grande vitesse, ce qui a donné les podiums suivants :  Technique long avec 17 postes : 1er Jurg Niggli, O’Jura en 52:48, 2e Beat Muller, COLJ Lausanne-Jorat en 58:02, 3e Christophe Vuitton, CO CERN en 58:19 Technique moyen avec 13 postes : 1er Jean-Bernard Zosso, CO CERN, en 46:05 ; 2e Yves Rousselot, Balise 25 Besançon, en 55:11 ; 3e Laurent Merat, O'Jura, en 55:13 Technique court avec 13 postes : 1er Julien Vuitton, CO CERN en 40:59, 2e Marc Baumgartner, CO CERN en 43:18, 3e Yaelle Mathieu en 51:42 Su...

  15. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Courses d’orientation ce printemps Le Club d’orientation du CERN vous invite à venir découvrir la course d’orientation et vous propose, en partenariat avec d’autres clubs de la région, une dizaine de courses populaires. Celles-ci ont lieu les samedis après-midi, elles sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel, en promenade ou en course. Si vous êtes débutant vous pouvez profiter d’une petite initiation offerte par l’organisateur avant de vous lancer sur un parcours. Divers types de parcours sont à votre choix lors de chaque épreuve : facile court (2-3 km), facile moyen (3-5 km), technique court (3-4 km), technique moyen (4-5 km) et technique long (5-7 km). Les dates à retenir sont les suivantes : Samedi 23 mars: Pully (Vd) Samedi 13 avril: Pougny...

  16. STABILITY IN THE CIRCULAR PIPE FLOW OF FIBER SUSPENSIONS

    Institute of Scientific and Technical Information of China (English)

    You Zhen-jiang; Lin Jian-zhong

    2003-01-01

    A linear stability analysis on the circular pipe flow of fiber suspensions is presented. The fiber orientation tensors are used to describe the characteristics of the orientation distribution of fibers. The constitutive equation for the fiber suspensions is set up and the modified Orr-Sommerfeld stability equation is derived. An improved finite difference method with high order accuracy is employed to solve the equation. The Newtonian pipe Poiseuille flow corresponding to H=0 is also analyzed for comparison. The results reveal that the fiber additives will enhance the flow stability, the degree of enhancement becomes high with the increases of the parameter H which accounts for the fiber resistance to the stretching along its axis. Fiber suspensions with large H can suppress the influence of high Reynolds number on the flow stability. Particularly, fibers give a higher attenuation of the short waves of disturbance.

  17. GFOC Project results: High Temperature / High Pressure, Hydrogen Tolerant Optical Fiber

    Energy Technology Data Exchange (ETDEWEB)

    E. Burov; A. Pastouret; E. Aldea; B. Overton; F. Gooijer; A. Bergonzo

    2012-02-12

    Tests results are given for exposure of multimode optical fiber to high temperatures (300 deg. C) and high partial pressure (15 bar) hydrogen. These results demonstrate that fluorine down doped optical fibers are much more hydrogen tolerant than traditional germanium doped multimode optical fibers. Also demonstrated is the similar hydrogen tolerance of carbon coated and non-carbon coated fibers. Model for reversible H2 impact in fiber versus T{sup o}C and H2 pressure is given. These results have significant impact for the longevity of use for distributed temperature sensing applications in harsh environments such as geothermal wells.

  18. Orientation tuning of human face processing estimated by contrast matching in transparency displays.

    Science.gov (United States)

    Martini, Paolo; McKone, Elinor; Nakayama, Ken

    2006-06-01

    Upright images of faces appear more salient than faces of other orientations. We exploited this effect in a titration experiment where faces were superimposed in transparency. By manipulating the physical contrast of the component images, we measured the degree of perceptual dominance as function of the orientation of the face in the image plane. From these measurements, we obtain the orientation tuning of face processing, which is well approximated by a Gaussian function with a SD of about 45 deg and mean centered on upright. Faces predominantly lit from above and from below produced very similar results. However, when presented with scrambled faces observers showed no orientation preference. We argue that these results can be explained by the existence of specialized face processing mechanisms with an orientation tuning with a bandwidth of approximately 90 deg, predominantly centered on the upright orientation and easily disrupted by alterations of the normal facial configuration.

  19. A note on design of fiber-nets for maximum stiffness

    DEFF Research Database (Denmark)

    Pedersen, Pauli

    2003-01-01

    For a specific fiber-net, the design variables are relative fiber density and fiber orientations. With a given amount of fibers, our objective is to maximize the stiffness (minimize the compliance) for a continuum subjected to a given load situation. Analytical optimality criteria are derived...

  20. A note on Design of Fiber-nets for Maximum Stiffness

    DEFF Research Database (Denmark)

    Pedersen, Pauli; Redanz, Pia; Tvergaard, V.

    For a specific fiber-net, the design variables are relative fiber density and fiber orientations. With a given amount of fibers our objective is to maximize the stiffness (minimize the compliance) for a continuum subjected to a given load situation. Analytical optimally criteria are derived...

  1. Primary instabilities and bicriticality in fiber suspensions between rotating cylinders

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The linear stability of fiber suspensions between two concentric cylinders rotating independently is studied. The modified stability equation is obtained based on the fiber orientation model and Hinch-Leal closure approximation. The primary instabilities and bicritical curves have been calculated numerically. The critical Reynolds number, wavenumber and wave speeds of fiber suspensions as functions of the aspect ratio, volume concentration of the fibers and the gap width of cylinders are obtained.

  2. Fiber Bragg Gratings in Small-Core Ge-Doped Photonic Crystal Fibers

    Institute of Scientific and Technical Information of China (English)

    Yiping Wang; Hartmut Bartelt; Wolfgang Ecke; Reinhardt Willsch; Jens Kobelke; Michael Kautz; Sven Brueckner; Manfred Rothhardt

    2008-01-01

    This paper reports fiber Bragg gratings (FBGs) inscribed in a small-core Ge-doped photonic crystal fibers with a UV laser and a Talbot inter-ferometer. The responses of such FBGs to temper-ature, strain, bending, and transverse-loading were systematically investigated. The Bragg wavelength of the FBGs shifts toward longer wavelengths with increasing temperature, tensile strain, and trans-verse-loading. The bending and transverse- loading properties of the FBGs are sensitive to the fiber orientations.

  3. Using Paraffin with -10 deg C to 10 deg C Melting Point for Payload Thermal Energy Storage in SpaceX Dragon Trunk

    Science.gov (United States)

    Choi, Michael K.

    2013-01-01

    A concept of using paraffin wax phase change material (PCM) with a melting point between -10 deg C and 10 deg C for payload thermal energy storage in a Space Exploration Technologies (SpaceX) Dragon trunk is presented. It overcomes the problem of limited heater power available to a payload with significant radiators when the Dragon is berthed to the International Space Station (ISS). It stores adequate thermal energy to keep a payload warm without power for 6 hours during the transfer from the Dragon to an ExPRESS logistics carrier (ELC) on the ISS.

  4. Far-infrared and submillimeter survey of the galactic plane from l = 11.5 deg to l = 17.5 deg

    Science.gov (United States)

    Campbell, M. F.; Niles, D. W.; Silverberg, R. F.; Hauser, M. G.; Stier, M. T.; Kelsall, T.; Hoffmann, W. F.; Thronson, H. A., Jr.

    1984-01-01

    Medium resolution (11 min) maps of the galactic plane are presented from l = 11.5 deg to l = 17.5 deg at wavelengths of 93 microns, 154 microns, and 190 microns. The maps are interpreted in terms of the temperature and spatial structure of diffuse far-infrared/submillimeter sources associated with evolved H II regions and a continuous ridge of galactic emission. The emission regions are found to be more extended at the longer wavelengths which implies that there must be a range of dust temperatures in the sources. The properties of the galactic ridge are similar to those of the sources.

  5. Polarization-maintaining fiber loop with double optical length and its application to fiber optic gyroscope

    Institute of Scientific and Technical Information of China (English)

    Changsheng Li; Chunxi Zhang; Ningfang Song; Hongjie Xu

    2011-01-01

    @@ A novel polarization maintaining fiber (PMP) loop is proposed and used for an interferometric fiber optic gyroscope (FOG). By splicing a conventional PMF loop with two pigtailed polarization beam splitters, polarized light can be guided to propagate along the slow and fast axes of the PMF in sequence to double its effective optical length in the loop. In particular, the resultant optical length in the combined loop is partially self-compensated for some external disturbances, such as transverse strain. Primary experiments on the FOG using the proposed loop demonstrate that the average static bias deviation between -40 and +60 ℃ is less than 0.050 deg./h, and the average bias variation under conventional random vibration test is less than 0.10 deg./h.%A novel polarization maintaining fiber (PMF) loop is proposed and used for an interferometric fiber optic gyroscope (FOG). By splicing a conventional PMF loop with two pigtailed polarization beam splitters,polarized light can be guided to propagate along the slow and fast axes of the PMF in sequence to double its effective optical length in the loop. In particular, the resultant optical length in the combined loop is partially self-compensated for some external disturbances, such as transverse strain. Primary experiments on the FOG using the proposed loop demonstrate that the average static bias deviation between -40 and +60 ℃ is less than 0.050 deg./h, and the average bias variation under conventional random vibration test is less than 0.10 deg./h.

  6. Diode Pumped Fiber Laser.

    Science.gov (United States)

    1984-12-01

    FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION .............. 5 A. FIBER GROWTH .......................... 5 B. FIBER PROCESSING 7...1.32 pm FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION A. FIBER GROWTH The single crystal fibers used in this work were grown at Stanford University

  7. Quantification of metallic iodides in fucus vesiculosus and serratus heated at 80 deg, 550 deg and 1 000 deg; Quantification des iodures metalliques dans des cendres d'algues. Analyse de fucus vesiculosus et serratus chauffees a 80 degres, 550 degre et 1000 degre

    Energy Technology Data Exchange (ETDEWEB)

    Aujollet, Y. [Direction Generale de la Surete Nucleaire et de la Radioprotection (DGSNR), 75 - Paris (France)

    2004-02-01

    Metallic iodides in aqueous phase of Fucus ashes were measured by gamma spectrometry. Before the measurements, different samples of Fucus were heated at 80 deg C (Fucus vesiculosus), 550 deg C (Fucus serratus) and 1 000 deg C (Fucus serratus). The first results gave 63% of iodide salts in Fucus vesiculosus heated at 80 deg C, 27% of iodide salts in Fucus serratus (550 deg C) and no result for ashes of Fucus serratus heated at 1 000 deg C, because there was not enough mass of product for a good analysis by gamma spectrometry. (author)

  8. Fiber optic and laser sensors V; Proceedings of the Meeting, San Diego, CA, Aug. 17-19, 1987

    Science.gov (United States)

    De Paula, Ramon P. (Editor); Udd, Eric (Editor)

    1988-01-01

    The papers contained in this volume focus on recent developments in fiber optic and laser sensors. Topics discussed include electric and magnetic field sensors, fiber optic pressure sensors, fiber optic gyros, fiber optic sensors for aerospace applications, fiber sensor multiplexing, temperature sensors, and specialized fiber optic sensors. Papers are presented on remote fiber optic sensors for angular orientation; fiber optic rotation sensor for space missions; adaptation of an electro-optic monitoring system to aerospace structures; optical fiber sensor for dust concentration measurements; and communication-sensing system using a single optical fiber.

  9. Club Orientation

    CERN Multimedia

    Club d'orientation

    2014-01-01

      COURSE ORIENTATION   Pas moins de 100 concurrents sont venus s’affronter sur les parcours proposés par le club d’orientation du CERN ce samedi 26 avril lors de la 4e étape de la coupe genevoise de printemps. Les podiums ont été attribués à :  Technique long avec 19 postes : 1er Yvan Balliot, ASO Annecy en 1:01:39 ; 2e Dominique Fleurent, ASO Annecy, en 1:05:12 ; 3e Rémi Fournier, SOS Sallanches, en 1:05:40. Technique moyen avec 14 postes : 1er Jean-Bernard Zosso, CO CERN, en 46:42 ; 2e Céline Zosso, CO CERN, en 50:51 ; 3e Clément Poncet, O’Jura Prémanon, en 51:27. Technique court avec 13 postes : 1er Jaakko Murtomaki, YKV Seinaejoki, en 36:04 ; 2e Marc Baumgartner en 41:27 ; 3e Natalia Niggli, O’Jura Prémanon, en 52:43. Sur les parcours facile moyen et facile court, victoire respectivement de Stéphanie...

  10. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2012-01-01

     Course d’orientation C’est sous un magnifique soleil que s’est tenue la 7e épreuve de la coupe genevoise organisée par le club d’orientation du CERN. Les organisateurs avaient concocté des parcours assez techniques sur le site de La Faucille. Sur le parcours technique long, beau podium avec la victoire de Domenico Lepori (double médaillés aux championnats du monde en 2010 en vétéran) du club Care Vevey en 1:00:23, juste devant Jürg Niggli du club O’Jura en 1:00:56 puis Beat Mueller du club Lausanne-Jorat en 1:04:28. Sur le parcours technique moyen, Franck Longchampt s’est octroyé la première place, sur le parcours technique court, le jeune Julien Vuitton, qui n’a pas tout à fait 11 ans, a remporté son circuit. Coté parcours facile moyen, Victor Kuznetsov a une fois de plus gagn&eacut...

  11. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2013-01-01

    Course d’orientation Face aux Championnats de France des Clubs à Poitiers, et à une météo hivernale (vent glaciale et pluie), il ne restait qu’une cinquantaine d’orienteurs pour participer à l’épreuve organisée le samedi 25 mai à Grange-Malval. Les participants ont tout de même bien apprécié les 5 circuits proposés par le Satus Genève. Les résultats sont disponibles sur notre site http://cern.ch/club-orientation. En plus des résultats, vous pourrez noter des informations sur la nouvelle école de CO encadrée par B. Barge, Prof. EPS à Ferney-Voltaire pour les jeunes à partir de 6 ans. La prochaine étape de la coupe genevoise se déroulera samedi 1er juin à Morez (39). Epreuve organisée par le club O’Jura&nb...

  12. Orienteering club

    CERN Multimedia

    Club d'orientation

    2010-01-01

    Course d’orientation : Coupe Genevoise de printemps 2010 Et c’est reparti pour une nouvelle saison! Pour cette coupe de printemps 2010, le Club d’Orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose le calendrier suivant: – samedi 20 mars : Cossonay (Vd) – samedi 10 avril : Echallens (Vd) – samedi 17 avril : Trélex (Vd) – samedi 24 avril : Genolier (Vd) – samedi 1 mai : Vulbens/Valleiry (74) – samedi 8 mai : Bois de la Rippe (Vd) – samedi 29 mai : Sauvabellin (Vd) : relais – samedi 5 juin: St Cergue (Vd) : grande finale Les courses populaires ont lieu en général le samedi après-midi, elles sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel, en promenade ou en course. Pour cela, divers types de parcours sont &agr...

  13. Orienteering club

    CERN Multimedia

    Club d’Orientation du CERN

    2015-01-01

    Courses d’orientation Nouvelle saison nouveau programme Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose une dizaine de courses populaires comptant pour la coupe Genevoise de printemps: samedi 28 mars: Vernand Dessus samedi 18 avril: Pougny/Challex samedi 25 avril: Chancy/Valleiry samedi 2 mai: Mauvernay samedi 9 mai: Longchaumois samedi 16 mai: Genolier samedi 30 mai: Prevondavaux samedi 6 juin: Biere-Ballens samedi 13 juin: Haut-Jura samedi 20 juin: Bonmont - Finale Ces courses sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel, en promenade ou en course. Les inscriptions se font sur place le jour de l’épreuve. Si vous êtes débutant, vous pouvez profiter d’une initiation offerte par l’organisateur avant de vous lancer sur un parcours. Le club propose aussi...

  14. Orienteering club

    CERN Multimedia

    Orienteering Club

    2016-01-01

    Course d'orientation Calendrier des courses d’orientation Coupe genevoise d’automne 2016 Samedi 3 septembre : La Faucille (01) Samedi 10 septembre : Prémanon (39) Samedi 17 septembre : Saint-Cergue (VD) Samedi 24 septembre : Jorat / Corcelles (VD) Samedi 1 octobre: Bière - Ballens (VD) -relais Vendredi 14 octobre : Parc Mon Repos (GE) - nocturne Samedi 15 octobre : Terrasse de Genève (74) Samedi 29 octobre : Bonmont (VD) Samedi 5 novembre : Pomier (74) – one-man-relay - Finale   Courses ouvertes à toutes et à tous, sportifs, familles, débutants ou confirmés, du CERN ou d’ailleurs. Cinq circuits disponibles, ceci va du facile court (2 km) adapté aux débutants et aux enfants jusqu’au parcours technique long de 6 km pour les chevronnés en passant par les parcours facile moyen (4&am...

  15. COURSE ORIENTATION

    CERN Multimedia

    Club d'orientation du CERN

    2015-01-01

      Les coureurs d’orientation de la région se sont donné rendez-vous samedi dernier dans les bois de Pougny/Challex lors de l’épreuve organisée par le club d’orientation du CERN. La carte proposée pour les 5 circuits offrait aussi bien un coté très technique avec un relief pentu qu’un coté avec de grandes zones plates à forêt claire. Le parcours technique long comportant 20 postes a été remporté par Beat Muller du COLJ Lausanne en 56:26 devançant Denis Komarov, CO CERN en 57:30 et Yvan Balliot, ASO Annecy en 57:46. Pour les autres circuits les résultats sont les suivants: Technique moyen (13 postes): 1er Joël Mathieu en 52:32 à une seconde du 2e Vladimir Kuznetsov, COLJ Lausanne-Jorat, 3e Jean-Bernard Zosso, CO CERN, en 54:01 Technique court (12 postes): 1er Lennart Jirden, ...

  16. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2017-01-01

    Calendrier des courses de la Coupe Genevoise – printemps 2017 Club d'orientation - Julien,  jeune membre du club. Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose une série de courses populaires, qui se dérouleront des deux côtés de la frontière franco-suisse, à savoir : Samedi 1 avril : Pougny/Challex (01) Samedi 8 avril: Ballens (VD) Samedi 22 avril: Apples (VD) Samedi 29 avril: Mont Mussy (01) Samedi 6 mai: Prémanon (39) Samedi 13 mai: Mont Mourex (01) Samedi 20 mai: Prévondavaux (VD) Samedi 10 juin: Chancy/Valleiry (74) Samedi 17 juin: Trélex - Finale (VD) Ces courses sont ouvertes à tous, quel que soit le niveau, du débutant au sportif confirmé, en famille ou en individuel. Les inscriptions sur un des 5 parcours proposés se font sur place le jour de...

  17. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2010-01-01

    COURSE D’ORIENTATION La finale de la coupe de printemps Après avoir remporté le challenge club, samedi 29 juin lors du relais inter-club à Lausanne, le Club d’orientation du CERN organisait la dernière étape de la coupe genevoise de printemps samedi 5 juin à Saint-Cergue dans les bois de Monteret (Canton de Vaud). Plus de 100 participants se sont déplacés pour venir participer à la finale et découvrir une toute nouvelle carte dans une forêt vallonnée. Les résultats pour chaque circuit de cette étape sont : Technique long : 1. Jurg Niggli du club O’Jura, 2. Clément Poncet, 3. Oystein Midttun. Technique moyen : 1. Zoltan Trocsanyi CO CERN, 2. Christophe Ingold, 3. Christina Falga. Technique court : 1. Pierre-Andre Baum, CARE Vevey, 2. Emese Szunyog, 3. Solène Balay. Facile moyen : 1. Elisa P...

  18. Orienteering Club

    CERN Multimedia

    Le Club d’orientation du CERN

    2017-01-01

    Course orientation Les courses d’orientation comptant pour la coupe genevoise de printemps s’enchainent dans la région franco-suisse. Samedi dernier, une bonne centaine de coureurs se sont retrouvés au Mont Mourex où le club du CERN avait préparé la sixième épreuve. A l’issue de la course, les participants confirmaient l’exigence des circuits, à savoir la condition physique et le côté technique du traçage. Le parcours technique long comportant 20 postes a été remporté par Darrell High du Care Vevey en 1:22:38 devançant Beat Muller du COLJ Lausanne-Jorat en 1:25:25 et Alison High également du Care Vevey en 1:28:51. Le circuit technique moyen a été remporté par Christophe Vuitton du CO CERN et le circuit technique court par Claire-Lise Rouiller, CO CERN. Les trois pr...

  19. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2015-01-01

    Course orientation C’est au pied du Salève, proche du Golf de Bosset, que le club d’orientation du CERN (CO CERN) a organisé samedi 19 septembre une nouvelle épreuve comptant pour la Coupe Genevoise d’automne. La zone « des Terrasses de Genève » avait été cartographiée et mise en service l’année dernière. Les participants ont pu apprécier un terrain ludique avec beaucoup de microreliefs, de points d’eau et de gros rochers, le tout au milieu d’une forêt assez claire et agréable à courir. Sur le parcours technique long, le résultat a été très serré puisque Pierrick Merino du club d’Annecy a gagné avec seulement 9 secondes d’avance sur Gaëtan Vuitton (CO CERN) qui confiait avoir perdu beaucoup du te...

  20. Products Distribution of Meta-Oriented Aromatic Polyamide Needs Improvement

    Institute of Scientific and Technical Information of China (English)

    Sun Maojian

    2007-01-01

    @@ Capacity holding the second place in the world Metaoriented aromatic polya-mide fiber was first developed by DuPont of the United States. Commercial production began in the late 1960s.Today the world's capacity to produce meta-oriented aromatic polyamide fiber is 28 150t/a, and DuPont holds a 78% market share.

  1. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    Directory of Open Access Journals (Sweden)

    A.E. Ismail

    2015-12-01

    Full Text Available This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that fiber orientations greatly affected the ultimate tensile strength but it is not for modulus of elasticity for both types of layers. It is estimated that the reductions of both ultimate tensile strength and Young’s modulus are in the range of 27.7-30.9% and 2.4-3.7% respectively, if the inclined fibers are used with respect to the principal axis.

  2. Two Fiber Optical Fiber Thermometry

    Science.gov (United States)

    Jones, Mathew R.; Farmer, Jeffery T.; Breeding, Shawn P.

    2000-01-01

    An optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber is essentially an isothermal cavity, so the emission from this cavity will be approximately equal to the emission from a blackbody. Temperature readings are obtained by measuring the spectral radiative heat flux at the end of the fiber at two wavelengths. The ratio of these measurements and Planck's Law are used to infer the temperature at the sensing tip. Optical fiber thermometers have high accuracy, excellent long-term stability and are immune to electromagnetic interference. In addition, they can be operated for extended periods without requiring re-calibration. For these reasons. it is desirable to use optical fiber thermometers in environments such as the International Space Station. However, it has recently been shown that temperature readings are corrupted by emission from the fiber when extended portions of the probe are exposed to elevated temperatures. This paper will describe several ways in which the reading from a second fiber can be used to correct the corrupted temperature measurements. The accuracy and sensitivity to measurement uncertainty will be presented for each method.

  3. In situ observations of BrO over Antarctica - ER-2 aircraft results from 54 deg S to 72 deg S latitude

    Science.gov (United States)

    Brune, W. H.; Anderson, J. G.; Chan, K. R.

    1989-01-01

    Bromine monoxide was observed in situ during nine flights of the NASA ER-2 aircraft from Punta Arenas, Chile (54 deg S latitude), to 72 deg S latitude over the Palmer Peninsula, Antarctica. The first flight for the BrO detection system was on August 28. The distribution of BrO inside the chemically perturbed region defined by greatly elevated ClO abundances was different from that found just outside. Inside, the BrO mixing ratio was 6.1 + or - 1.1 pptv above the 440 K potential temperature surface, 4.7 + or - 2.0 pptv between the 400 and 440 K surfaces, and less than 4 pptv below the 400 K surface. At high latitudes outside the chemically perturbed region, the BrO mixing ratio was 5.4 + or - 1.4 pptv near the 450 K surface, but decreased to 2.9 + or - 1.2 pptv at the 420 K surface. The abundance of BrO showed no discernible temporal trend during the course of the nine flights. Away from the south polar region, at latitudes between 47 deg S and 37 deg N and potential temperatures between 435 and 500 K (18.5- to 20.7-km altitude), the BrO mixing ratio was 0.5-3.0 pptv.

  4. Role of humidity on the structures and properties of regenerated silk fibers

    Directory of Open Access Journals (Sweden)

    Qingfa Peng

    2015-10-01

    Full Text Available Silk fiber was processed from highly concentrated spinning dope to solid fibers along with water removal. To understand the mechanism of water removal during silk fiber spinning process, a microfluidic chip was designed and applied to investigate the structures and mechanical properties of two kinds of regenerated silk fibroin fibers dry-spun at different relative humidity. The experimental results showed that the diameters of the fibers spun at 40% RH are always larger than the fibers spun at 50% RH due to different removal rates of water. The fibers spun at low humidity contain more β-sheet structure and lower degree of chain orientation and crystalline orientation. These results indicate that the fast phase transition of silk fibroin from sol–gel to silk fiber undergoes with rapid water removal and higher fiber orientation relates to more residue water and drawing force.

  5. Simplified 2DEG carrier concentration model for composite barrier AlGaN/GaN HEMT

    Energy Technology Data Exchange (ETDEWEB)

    Das, Palash, E-mail: d.palash@gmail.com; Biswas, Dhrubes, E-mail: d.palash@gmail.com [Indian Institute of Technology Kharagpur, Kharagpur - 721302, West Bengal (India)

    2014-04-24

    The self consistent solution of Schrodinger and Poisson equations is used along with the total charge depletion model and applied with a novel approach of composite AlGaN barrier based HEMT heterostructure. The solution leaded to a completely new analytical model for Fermi energy level vs. 2DEG carrier concentration. This was eventually used to demonstrate a new analytical model for the temperature dependent 2DEG carrier concentration in AlGaN/GaN HEMT.

  6. Strumentazione multisensore selettiva per il monitoraggio in continuo degli odori nel settore ambientale

    OpenAIRE

    Giuliani, Stefano

    2012-01-01

    2010 - 2011 L’odore indotto dall’esercizio degli impianti di ingegneria sanitaria ambientale è ritenuto la causa principale di disturbo che la popolazione residente nelle vicinanze avverte. Sebbene alle emissioni odorigene sia solo raramente associato un reale rischio tossicologico-sanitario, sia per la natura raramente pericolosa degli odoranti che per le concentrazioni generalmente molto basse, nell’immaginario collettivo, ai cattivi odori si associano spesso condizioni di “non salubrità...

  7. Experimental measurement of the solubility of bismuth phases in water vapor from 220 deg. C to 300 deg. C: Implications for ore formation

    Energy Technology Data Exchange (ETDEWEB)

    Kruszewski, Jason M. [Department of Geological Sciences, University of Idaho, Moscow, ID 83844-3022 (United States); Wood, Scott A., E-mail: swood@uidaho.edu [Department of Geological Sciences, University of Idaho, Moscow, ID 83844-3022 (United States)

    2009-04-15

    Preliminary measurements were carried out of the solubility of the O{sub 2-}buffering assemblage bismuth + bismite (Bi{sub 2}O{sub 3}) in aqueous liquid-vapor and vapor-only systems at temperatures of 220, 250 and 300 deg. C. All experiments were carried out in Ti reaction vessels and were designed such that the Bi solids were contained in a silica tube that prevented contact with liquid water at any time during the experiment. Two blank (no Bi solids present) liquid-vapor experiments at 220 deg. C yielded Bi concentrations ({+-}1{sigma}) in the condensed liquid of 0.22 {+-} 0.02 mg/L, whereas the solubility measurements at this temperature yielded an average value of approximately 6 {+-} 9 mg/L, with replicate experiments ranging from 0.3 to 26 mg/L. Although the 6 mg/L value is associated with a considerable degree of uncertainty, the experiments do indicate transport of Bi through the vapor phase. Measured Bi concentrations in the condensed liquid at 250 deg. C were in the same range as those at 220 deg. C, whereas those at 300 deg. C were significantly lower (i.e., all below the blank value). Vapor-only experiments necessarily contained much smaller initial volumes of water, thereby making the results more susceptible to contamination. Single blank runs at 220 and 300 deg. C yielded Bi concentrations of 82 and 16 mg/L, respectively. Measured concentrations ({+-}1{sigma}) of Bi in the vapor-only solubility experiments at 220 deg. C were 235 {+-} 78 mg/L for an initial water volume of 0.5 mL, and at 300 deg. C were 56 {+-} 30 mg/L and 33 {+-} 21 for initial water volumes of 1 and 2 mL, respectively, suggesting strong preferential partitioning of Bi into the vapor. The results indicate a negative dependence of Bi solubility on temperature, but are inconclusive with respect to the dependence of Bi solubility on water density or fugacity. The experiments reported here suggest that significant Bi transport is possible in the vapor phase. Comparison of the liquid

  8. Evaluation of myocardial SPECT imaging reconstructed from 270deg projection data. A study using a cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    Kashikura, Kenichi [Japan Science and Technology Corp., Akita (Japan). Akita Lab.; Kobayashi, Hideki; Kashikura, Akemi

    1997-01-01

    SPECT reconstruction is commonly performed using 360deg or 180deg projection data. However, it is also possible to reconstruct SPECT images using other projection data arcs. The purpose of this study was to characterize images obtained by limiting the projection data to 270deg by discarding the projection views with severe attenuation. A series of phantom studies was performed with and without plastic chambers simulating perfusion defects using {sup 201}Tl and {sup 99m}Tc. Images using 270deg, 360deg, and 180deg projection arcs were identically reconstructed from the same data. In the absence of plastic chambers, intraslice uniformity in a given slice was assessed by computing the coefficient of variation (CV) of average counts in 8 ROIs within the slice. Interslice uniformity was assessed by computing the CV of average counts in five short axial slices. With plastic chambers in place, the variability in defect contrasts was assessed by computing the CV of defect contrasts in 4 chambers, located on the anterior, lateral, inferoposterior, and septal walls. The intraslice uniformity of the 270deg images were considerably inferior to those of the 360deg and 180deg images. The interslice uniformity was highest in the 360deg images, and lowest in the 180deg images. The variation in defect contrasts in the 270deg image was higher than those of the other two images. The 270deg images showed a high defect contrast in the septum and high counts in the anterior and anteroseptal wall. Because a large variation in defect contrasts within a segment might result in false positive or negative in diagnosis, 270deg imaging is not recommended over 360deg or 180deg imaging. (author)

  9. Synthesis of polyacrylonitrile (PAN) with different stereoregularity by urea radiation inclusion polymerization and its application to carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

    Fujikura, Yoshiaki; Minakawa, Masaaki [Yamagata Univ., Yonezawa (Japan). Faculty of Engineering; Makuuchi, Keizo; Matsuo, Masaru; Yoshii, Fumio

    1998-01-01

    Application to carbon fiber started in this Year. In this paper, a spinning and calcination process are explained. Fiber was obtained by wet spinning of the PAN solution. Ten solvents were tested and the results proved that dimethyl sulfoxide (DMSO) was the best solvent. Glycerine was used as a coagulating bath. The thin fiber (10 to 50 denier) was produced under the conditions of about 20wt% concentration at about 110degC. Heat-treat temperature was about 270 to 275degC. The viscosity-tacticity relationship and T{sub sol} vs. inverse tacticity were shown in the paper. (S.Y.)

  10. Vacuum fiber-fiber coupler

    Science.gov (United States)

    Heinrici, Axel; Bjelajac, Goran; Jonkers, Jeroen; Jakobs, Stefan; Olschok, Simon; Reisgen, Uwe

    2017-02-01

    Research and development carried out by the ISF Welding and Joining Institute of RWTH Aachen University has proven that combining high power laser and low vacuum atmosphere provides a welding performance and quality, which is comparable to electron beam welding. The developed welding machines are still using a beam forming which takes place outside the vacuum and the focusing laser beam has to be introduced to the vacuum via a suitable window. This inflexible design spoils much of the flexibility of modern laser welding. With the target to bring a compact, lightweight flying optics with flexible laser transport fibers into vacuum chambers, a high power fiber-fiber coupler has been adapted by II-VI HIGHYAG that includes a reliable vacuum interface. The vacuum-fiber-fiber coupler (V-FFC) is tested with up to 16 kW sustained laser power and the design is flexible in terms of a wide variety of laser fiber plug systems and vacuum flanges. All that is needed to implement the V-FFC towards an existing or planned vacuum chamber is an aperture of at least 100 mm (4 inch) diameter with any type of vacuum or pressure flange. The V-FFC has a state-of-the-art safety interface which allows for fast fiber breakage detection for both fibers (as supported by fibers) by electric wire breakage and short circuit detection. Moreover, the System also provides connectors for cooling and electric signals for the laser beam optics inside the vacuum. The V-FFC has all necessary adjustment options for coupling the laser radiation to the receiving fiber.

  11. Fabricación de compuesto de matriz epoxi reforzado con fibras largas de henequén orientadas aleatoriamente//Fabrication of a composite with epoxy matrix and henequen fibers as reinforcement long and with random orientation

    Directory of Open Access Journals (Sweden)

    Angel A. Rodríguez Soto

    2015-05-01

    Full Text Available Se obtuvo el procedimiento para la fabricación de un material compuesto con matriz de epoxi reforzado con fibras de henequén largas orientadas aleatoriamente. Fueron diseñados y elaborados seis moldes de tipo caja para la fabricación por el método de prensado en frío. Se produjeron 37 placas con 0, 6, 9, 12, 16, 22, 26 y 28 % de fibras en relación másica. La inclusión de los refuerzos fue manual y los materiales fabricados se sometieron a un proceso de cura a 70 ºC por 24 horas. Los especímenes obtenidos presentaron buena calidad estando libres de defectos y asegurando la distribución correcta de las fibras. El método de fabricación es adecuado para placas con pequeñas y grandes cantidades de fibra.Palabras claves: plásticos reforzados con fibras (PRF, fibras vegetales, compuesto de matriz termoestable, moldeo por compresión en frío.______________________________________________________________________________AbstractIs presented a procedure for the fabrication of the composite material with epoxy as matrix reinforced with henequen fibers, long and random. Was designed and fabricated six molds of box type for the manufacture of the plates using cold pressing procedure. Was make 37 plates with 0, 6, 9, 12, 16, 22, 26 and 28 % of fiber´s inclusions in mass relation. The inclusion of the reinforcements was making manually and the obtained materials was submitted to a process of cure bellow 70ºC during 24 hours. The obtained specimens showed a good quality being free of defects and guarantee the correct distribution of the fibers. The fabrication method is de adequate for plates with small and large quantities of fiber.Key words: fiber reinforced plastics (FRP, natural fibers, composite with thermoset matrix, cold compression molded.

  12. Orienteering club

    CERN Document Server

    Club d'orientation

    2011-01-01

    Reprise fin août Le Club d’orientation, en partenariat avec d’autres clubs de la région, vous propose une nouvelle série de courses pour cet automne. Le calendrier à retenir est le suivant : Samedi 27 août : Granges Malval (GE) – type classique Samedi 10 septembre : Lamoura (39) – type classique Samedi 17 septembre : La Dôle (F/VD) – type classique Samedi 24 septembre : Monteret (VD) – relais Samedi 8 octobre : Saint Cergue (VD) – type classique Vendredi 14 octobre : Les Evaux (GE) – nocturne Samedi 15 octobre : Grand Jorat (VD) – type classique Samedi 22 octobre : Pomier (74) – type classique Samedi 5 novembre : Echallens (VD) – type classique Samedi 12 novembre : CERN (GE) - sprint - Finale Généralement cinq circuits sont disponibles : ceci va du facile court (2 km) adapt&eacu...

  13. Orienting hypnosis.

    Science.gov (United States)

    Hope, Anna E; Sugarman, Laurence I

    2015-01-01

    This article presents a new frame for understanding hypnosis and its clinical applications. Despite great potential to transform health and care, hypnosis research and clinical integration is impaired in part by centuries of misrepresentation and ignorance about its demonstrated efficacy. The authors contend that advances in the field are primarily encumbered by the lack of distinct boundaries and definitions. Here, hypnosis, trance, and mind are all redefined and grounded in biological, neurological, and psychological phenomena. Solutions are proposed for boundary and language problems associated with hypnosis. The biological role of novelty stimulating an orienting response that, in turn, potentiates systemic plasticity forms the basis for trance. Hypnosis is merely the skill set that perpetuates and influences trance. This formulation meshes with many aspects of Milton Erickson's legacy and Ernest Rossi's recent theory of mind and health. Implications of this hypothesis for clinical skills, professional training, and research are discussed.

  14. EDITORIAL: Optical orientation Optical orientation

    Science.gov (United States)

    SAME ADDRESS *, Yuri; Landwehr, Gottfried

    2008-11-01

    priority of the discovery in the literature, which was partly caused by the existence of the Iron Curtain. I had already enjoyed contact with Boris in the 1980s when the two volumes of Landau Level Spectroscopy were being prepared [2]. He was one of the pioneers of magneto-optics in semiconductors. In the 1950s the band structure of germanium and silicon was investigated by magneto-optical methods, mainly in the United States. No excitonic effects were observed and the band structure parameters were determined without taking account of excitons. However, working with cuprous oxide, which is a direct semiconductor with a relative large energy gap, Zakharchenya and his co-worker Seysan showed that in order to obtain correct band structure parameters, it is necessary to take excitons into account [3]. About 1970 Boris started work on optical orientation. Early work by Hanle in Germany in the 1920s on the depolarization of luminescence in mercury vapour by a transverse magnetic field was not appreciated for a long time. Only in the late 1940s did Kastler and co-workers in Paris begin a systematic study of optical pumping, which led to the award of a Nobel prize. The ideas of optical pumping were first applied by Georges Lampel to solid state physics in 1968. He demonstrated optical orientation of free carriers in silicon. The detection method was nuclear magnetic resonance; optically oriented free electrons dynamically polarized the 29Si nuclei of the host lattice. The first optical detection of spin orientation was demonstrated by with the III-V semiconductor GaSb by Parsons. Due to the various interaction mechanisms of spins with their environment, the effects occurring in semiconductors are naturally more complex than those in atoms. Optical detection is now the preferred method to detect spin alignment in semiconductors. The orientation of spins in crystals pumped with circularly polarized light is deduced from the degree of circular polarization of the recombination

  15. Growth of single-crystal YAG fiber optics.

    Science.gov (United States)

    Nie, Craig D; Bera, Subhabrata; Harrington, James A

    2016-07-11

    Single-crystal YAG (Y3Al5O12) fibers have been grown by the laser heated pedestal growth technique with losses as low as 0.3 dB/m at 1.06 μm. These YAG fibers are as long as about 60 cm with diameters around 330 μm. The early fibers were grown from unoriented YAG seed fibers and these fibers exhibited facet steps or ridges on the surface of the fiber. However, recently we have grown fibers using an oriented seed to grow step-free fibers. Scattering losses made on the fibers indicate that the scattering losses are equal to about 30% of the total loss.

  16. Anisotropic Smoothing Improves DT-MRI-Based Muscle Fiber Tractography.

    Directory of Open Access Journals (Sweden)

    Amanda K W Buck

    Full Text Available To assess the effect of anisotropic smoothing on fiber tracking measures, including pennation angle, fiber tract length, and fiber tract number in the medial gastrocnemius (MG muscle in healthy subjects using diffusion-weighted magnetic resonance imaging (DW-MRI.3T DW-MRI data were used for muscle fiber tractography in the MG of healthy subjects. Anisotropic smoothing was applied at three levels (5%, 10%, 15%, and pennation angle, tract length, fiber tract number, fractional anisotropy, and principal eigenvector orientation were quantified for each smoothing level.Fiber tract length increased with pre-fiber tracking smoothing, and local heterogeneities in fiber direction were reduced. However, pennation angle was not affected by smoothing.Modest anisotropic smoothing (10% improved fiber-tracking results, while preserving structural features.

  17. INVESTIGATION ON SOUND ABSORPTION PROPERTIES OF KAPOK FIBERS

    Institute of Scientific and Technical Information of China (English)

    Hai-fan Xiang; Dong Wang; Hui-chao Liu; Ning Zhao; Jian Xu

    2013-01-01

    Sound absorption properties of natural kapok fibers have been investigated.Kapok fibrous assemblies with different bulk density,thickness,fiber length and orientation were manufactured,and their acoustical performances were evaluated by using an impedance tube instrument.Results show that the kapok fiber has excellent acoustical damping performance due to its natural hollow structure,and the sound absorption coefficients of kapok fibrous assemblies are significantly affected by the bulk density,thickness and arrangement of kapok fibers but less dependent on the fiber length.Compared with assemblies of commercial glass wool and degreasing cotton fibers,the kapok fiber assemblies with the same thickness but much smaller bulk density may have the similar sound absorption coefficients.Theoretical modelling of the acoustical damping performance of kapok fibers shows a good agreement with the experimental data.All the results demonstrate that kapok fiber is a promising light and environment-friendly sound absorption material.

  18. Near-field light scattering by parallel glass fibers

    Science.gov (United States)

    Benincasa, Daniel S.; Tsuei, Tak-Goa; Barber, Peter W.

    1987-09-01

    Single glass fibers whose radius-to-wavelength ratio is large, for example, r/λ=100, strongly focus normally incident laser light to give greatly enhanced intensities both within and in the near field of the fiber, even when the fiber is not at resonance. Calculated results show that the enhancement is dependent on the radius-to-wavelength ratio and on the fiber index of refraction. Even greater enhancements are observed for spherical particles. The near-field intensity for a single fiber is greatly modified when a second fiber is moved into its near field. Calculations of the near-field intensities for two coupled fibers provide insight into the coupling mechanism, especially the dependence of the coupling on the fiber separation and on the orientation of the two fibers relative to the incident wave.

  19. Wood versus plant fibers: Similarities and differences in composite applications

    DEFF Research Database (Denmark)

    Madsen, Bo; Gamstedt, E. Kristofer

    2013-01-01

    , and ultrastructure of the fibers, the modeling of the mechanical properties of the fibers, the fiber preforms available for manufacturing of composites, the typical mechanical properties of the composites, the modeling of the mechanical properties with focus on composites having a random fiber orientation and a non......-negligible porosity content, and finally, the moisture sensitivity of the composites. The performance of wood and plant fiber composites is compared to the synthetic glass and carbon fibers conventionally used for composites, and advantages and disadvantages of the different fibers are discussed. © 2013 Bo Madsen......The work on cellulose fiber composites is typically strictly divided into two separated research fields depending on the fiber origin, that is, from wood and from annual plants, representing the two different industries of forest and agriculture, respectively. The present paper evaluates...

  20. Multiple, Distant (40 deg) in situ Observations of a Magnetic Cloud and a Corotating Interaction Region Complex

    Science.gov (United States)

    Farrugia, C. J.; Berdichevsky, D. B.; Moestl, C.; Galvin, A. B.; Leitner, M.; Popecki, M.; Simunac, K. D.; Opitz, A.; Lavraud, B.; Ogilvie, K.; Veronig, A.; Temmer, M.; Luhmann, J. G.; Sauvaud, J.

    2010-12-01

    We report a comprehensive analysis of in situ observations made by Wind and the STEREO probes (STA, STB) of a complex interaction between a magnetic cloud (MC) and a corotating interaction region (CIR) occurring near the heliospheric current sheet (HCS) on November 19-21, 2007. The probes were separated by 0.7 AU (~40 deg) with a spread in heliographic latitudes (4.8, 2.2, and -0.4 deg for STB, Wind and STA, respectively). We employ data from the MFI, SWE and 3DP instruments on Wind, and the PLASTIC and IMPACT suites on STEREO. STB, located east of Earth, observed a forward shock followed by signatures of a MC. The MC took the role of the HCS in that the polarity of the interplanetary magnetic field (IMF) on exit was the reverse of that on entry. A passage through a plasma sheet is observed. Along the Sun-Earth line Wind observed a stream interface (SI) between a forward and a reverse shock. A MC, compressed by the CIR, was entrained in this. STA, located 20 deg to the west of Earth, saw a MC which was not preceded by a shock. A SI trailed the transient. The shocks are examined using various methods and from this it is concluded that the forward shock at Wind - but not at STB - was driven by the MC. Examining the MC by Grad-Shafranov reconstruction, we find evidence of a double-flux rope structure at Wind and STA and possibly also at STB. The orientations are at variance with the notion of a large-scale flux tube being observed at the three spacecraft. We find consistency of this with the directional properties of the solar wind "strahl" electrons. We examine aspects of the geomagnetic response and find a double-dip storm corresponding to the two interplanetary triggers. The minimum Dst phase was prolonged and the geoffects were intensified due to the interaction. We conclude that while the formation of compound streams is a common feature of interplanetary space, understanding their components when CIRs are involved is a complicated matter needing numerical

  1. Dietary fiber.

    Science.gov (United States)

    Madar, Z; Thorne, R

    1987-01-01

    Studies done on dietary fiber (DF) over the past five years are presented in this Review. The involvement of dietary fiber in the control of plasma glucose and lipid levels is now established. Two dietary fiber sources (soybean and fenugreek) were studied in our laboratory and are discussed herein. These sources were found to be potentially beneficial in the reduction of plasma glucose in non-insulin dependent diabetes mellitus subjects. They are shown to be acceptable by human subjects and are easy to use either in a mixture of milk products and in cooking. The mechanism by which dietary fiber alters the nutrient absorption is also discussed. The effect of DF on gastric emptying, transit time, adsorption and glucose transport may contribute to reducing plasma glucose and lipid levels. DF was found to be effective in controlling blood glucose and lipid levels of pregnant diabetic women. Dietary fiber may also be potentially beneficial in the reduction of exogenous insulin requirements in these subjects. However, increased consumption of DF may cause adverse side effects; the binding capabilities of fiber may affect nutrient availability, particularly that of minerals and prolonged and high DF dosage supplementation must be regarded cautiously. This is particularly true when recommending such a diet for pregnant or lactating women, children or subjects with nutritional disorders. Physiological effects of DF appear to depend heavily on the source and composition of fiber. Using a combination of DF from a variety of sources may reduce the actual mass of fiber required to obtain the desired metabolic effects and will result in a more palatable diet. Previously observed problems, such as excess flatus, diarrhea and mineral malabsorption would also be minimized.

  2. In situ observation of magnetic orientation process of feeble magnetic materials under high magnetic fields

    Directory of Open Access Journals (Sweden)

    Noriyuki Hirota et al

    2008-01-01

    Full Text Available An in situ microscopic observation of the magnetic orientation process of feeble magnetic fibers was carried out under high magnetic fields of up to 10 T using a scanning laser microscope. In the experiment, carbon fibers and needle-like titania fibers with a length of 1 to 20 μm were used. The fibers were observed to gradually orient their axes parallel to the direction of the magnetic field. The orientation behavior of the sample fibers was evaluated on the basis of the measured duration required for a certain angular variation. As predicted from the theoretical consideration, it was confirmed that the duration required for a certain angular variation normalized by the viscosity of the fluid is described as a function of the fiber length. The results obtained here appear useful for the consideration of the magnetic orientation of materials suspended in a static fluid.

  3. Regional heterogeneity in muscle fiber strain: The role of fiber architecture

    Directory of Open Access Journals (Sweden)

    E. eAzizi

    2014-08-01

    Full Text Available The force, mechanical work and power produced by muscle fibers are profoundly affected by the length changes they undergo during a contraction. These length changes are in turn affected by the spatial orientation of muscle fibers within a muscle (fiber architecture. Therefore any heterogeneity in fiber architecture within a single muscle has the potential to cause spatial variation in fiber strain. Here we examine how the architectural variation within a pennate muscle and within a fusiform muscle can result in regional fiber strain heterogeneity. We combine simple geometric models with empirical measures of fiber strain to better understand the effect of architecture on fiber strain heterogeneity. We show that variation in pennation angle throughout a muscle can result in differences in fiber strain with higher strains being observed at lower angles of pennation. We also show that in fusiform muscles, the outer/superficial fibers of the muscle experience lower strains than central fibers. These results show that regional variation in mechanical output of muscle fibers can arise solely from architectural features of the muscle without the presence of any spatial variation in motor recruitment.

  4. Deletion of degQ gene enhances outer membrane vesicle production of Shewanella oneidensis cells.

    Science.gov (United States)

    Ojima, Yoshihiro; Mohanadas, Thivagaran; Kitamura, Kosei; Nunogami, Shota; Yajima, Reiki; Taya, Masahito

    2017-04-01

    Shewanella oneidensis is a Gram-negative facultative anaerobe that can use a wide variety of terminal electron acceptors for anaerobic respiration. In this study, S. oneidensis degQ gene, encoding a putative periplasmic serine protease, was cloned and expressed. The activity of purified DegQ was inhibited by diisopropyl fluorophosphate, a typical serine protease-specific inhibitor, indicating that DegQ is a serine protease. In-frame deletion and subsequent complementation of the degQ were carried out to examine the effect of envelope stress on the production of outer membrane vesicles (OMVs). Analysis of periplasmic proteins from the resulting S. oneidensis strain showed that deletion of degQ induced protein accumulation and resulted in a significant decrease in protease activity within the periplasmic space. OMVs from the wild-type and mutant strains were purified and observed by transmission electron microscopy. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the OMVs showed a prominent band at ~37 kDa. Nanoliquid chromatography-tandem mass spectrometry analysis identified three outer membrane porins (SO3896, SO1821, and SO3545) as dominant components of the band, suggesting that these proteins could be used as indices for comparing OMV production by S. oneidensis strains. Quantitative evaluation showed that degQ-deficient cells had a fivefold increase in OMV production compared with wild-type cells. Thus, the increased OMV production following the deletion of DegQ in S. oneidensis may be responsible for the increase in envelope stress.

  5. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2011-01-01

    Coupe genevoise, suite Résultats de la course de Saint-Cergue, sur la carte Les Pralies, samedi 17 septembre. Nouvelle victoire du finlandais Ville Keskisaari, du club COLJ sur le parcours technique long avec une belle avance sur le deuxième concurrent Christophe Vuitton du CO CERN. David Cuenin a remporté le parcours technique moyen, Franck Lonchampt du club O’Jura a, lui aussi, remporté à nouveau le parcours technique court, tout comme Julien Vuitton du club CO CERN sur le facile moyen. Pour finir, Stéphane Clément devance Victor Dannecker sur le parcours facile court. Les résultats complets sont disponibles sur le site du club du CERN http://cern.ch/club-orientation. Un abonnement est pris sur le secteur de Saint-Cergue, puisque le club organise les deux prochaines étapes de la coupe genevoise dans le Haut-Jura suisse. Tout d’abord le samedi 24 septembre, un relais inter-club se courr...

  6. Orienteering club

    CERN Multimedia

    Club d'orientation

    2010-01-01

    COURSE D’ORIENTATION  De La Rippe à Sauvabellin, la coupe genevoise continue ! Le rendez-vous était donné samedi 8 mai aux amateurs de course d’orientation dans les bois de La Rippe (Canton de Vaud). Cette 6e épreuve était organisée par le Club Satus Grutli de Genève. Il est dommage que les participants n’aient pas été aussi nombreux que lors des dernières courses, les Championnats de France des clubs à Dijon ayant certainement retenus plus d’un compétiteur. La première place est revenue à : – Technique long : Berni Wehrle – Technique moyen : Jean-Bernard Zosso – Technique court : Berni Wehrle – Facile moyen : Peter Troscanyi – Facile court : Claire Droz. Il ne restera plus que deux épreuves ...

  7. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2012-01-01

    Course d'orientation Ces deux dernières semaines, le club a organisé la troisième puis la quatrième étape de la coupe de printemps, une dans la forêt de Collogny/Moissey près de Vulbens, l’autre vers le parcours vita de Trélex. Les résultats sont: Facile court Vulbens : 1er Léo Lonchampt, O’Jura (16:04), 2e Timothée Bazin (23:07), 3e Francesco Pieri (26:57) Trélex : 1er Noora Maurent (23:11), 2e Sarah Stuber, COLJ (26:51), 3e T. Bazin (28:17) Facile moyen Vulbens : 1er Victor Kuznetsov, CO CERN (25:36), 2e Didier Descourvières (28:03), 3e Konstantinos Haider, CO CERN (36:53) Trélex : 1er V. Kuznetsov, COLJ (38:01), 2e K. Haider, CO CERN (43:15), 3e ex aequo Olivia Nguyen et Sven Vietmeier (58:11) Technique court Vulbens : 1er Benoit Bazin (41:21), 2e Colas Gintzburger (55:12), 3e Nathan Freydoz (55:48) Trélex : 1...

  8. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2011-01-01

    Course d'orientation Avec la CO en nocturne organisée par le club du CERN vendredi 14 octobre au stade des Eveaux (Ge), et la CO à Savigny (Vd) proposée par le club de Lausanne-Jorat le lendemain, les étapes de la coupe genevoise d’automne s’enchainent rapidement. Il ne reste plus que 3 rendez-vous pour boucler la saison. Les premières places devraient certainement se jouer entre des membres du club du CERN, du O’Jura ou de Lausanne-Jorat. La prochaine course du club est programmée pour samedi 22 octobre à Pomier, près de Cruseilles. L’accueil se fera à partir de 12h30 et les départs s’échelonneront de 13h à 15h. * * * * * * * Nouvelle belle victoire samedi 8 octobre à Saint Cergue du jeune finlandais Ville Keskisaari (COLJ) en 50:56 devant Jürg Niggli (O’Jura) en 1:03:32, et Alexandre...

  9. Orienteering club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Course d'orientation Finale de la coupe genevoise Rapide et méthodique, voilà les qualités dont il fallait faire preuve pour remporter la dernière étape de la coupe organisée par le club du CERN dans les bois de Monteret. Il s’agissait d’une course au score où chaque concurrent disposait d’un temps imparti pour poinçonner le maximum de balises. Le parcours technique a été remporté par Tomas Shellman et le parcours facile par Victor Dannecker. Cette dernière étape était aussi décisive pour la désignation des lauréats de la coupe genevoise de printemps. Les résultats officiels étaient donnés par le président du club, L. Jirden : Circuit Technique Long : Berni Wehrle, Bruno Barge, Edvins Reisons Circuit Technique Moyen : J.-Bernard Zosso, ...

  10. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    De jour comme de nuit Les amateurs de course d’orientation ont pu s’en donner à cœur joie ce week-end puisqu’ils avaient la possibilité de courir sur deux épreuves en moins de 24 heures. En effet, le club du CERN organisait une course de nuit aux Evaux et la 7e étape de la coupe genevoise se tenait samedi après-midi dans les bois du Grand Jorat à Savigny. Les vainqueurs pour chaque course sont : Technique long CO de nuit: Julien Charlemagne, SOS Sallanches CO samedi: Philipp Khlebnikov, ANCO   Technique moyen CO de nuit: Céline Zosso, CO CERN CO samedi: Pavel Khlebnikov, ANCO Technique court CO de nuit: Colas Ginztburger, SOS Sallanches CO samedi: Victor Kuznetsov, COLJ Lausannne Facile moyen CO de nuit: Gaëtan Rickenbacher, CO CERN CO samedi: Tamas Szoke   Facile court CO de nuit:Oriane Rickenbacher, CO CERN CO samedi: Katya Kuznetsov...

  11. Orienteering club

    CERN Multimedia

    Club d'orientation

    2014-01-01

    Course d'orientation Finale de la coupe d’automne La dernière épreuve de la coupe d’automne organisée par le club s’est déroulée ce samedi 1er novembre avec une course type «one-man-relay» dans la forêt de Trelex (Vd). Les concurrents des circuits techniques devaient parcourir trois boucles et ceux des circuits «faciles» deux boucles, avec changements de carte. Le parcours technique long a été remporté par un membre du club, Berni Wehrle. A l’issue de cette course, le Président du club, L. Jirden annonçait le classement général de la coupe d’automne, basé sur les 6 meilleurs résultats de la saison : Circuit technique long : 1er Juerg Niggli (O’Jura), 2e Berni Wehrle, 3e Beat Mueller. Circuit technique moyen : 1er Laurent Merat (O&r...

  12. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2012-01-01

    Finale de la coupe d’automne   La coupe d’automne organisée par le club d’orientation du CERN s’est terminée ce samedi 10 novembre avec une course sprint à Prévessins. C’était la 12e épreuve de la saison. En stage dans la région, Tanya Ryabkina, championne d’Europe en titre et médaillée de bronze en moyenne distance lors des championnats du monde à La Givrine cet été, a fait l’honneur de sa présence et termine 2e à 8 secondes de Trygve Buanes, norvégien du club de Bergen. A l’issue de cette dernière épreuve, le classement général de la coupe d’automne, basé sur les 8 meilleurs résultats de la saison, est ainsi le suivant : Circuit technique long : 1er Jurg Niggli (O&rsqu...

  13. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Finale de la coupe d’automne La dernière épreuve de la coupe d’automne organisée par le club d’orientation du CERN s’est déroulée ce samedi 2 novembre avec une course au score dans le bois Tollot (GE). Les concurrents disposaient d’un temps imparti pour poinçonner le maximum de balises différemment placées selon le circuit choisi. Juerg Niggli (club O’Jura) a remporté le parcours technique long. A l’issue de cette course, le classement général de la coupe d’automne, basé sur les 6 meilleurs résultats de la saison, est le suivant : Circuit technique long : 1er Juerg Niggli (O’Jura), 2e Bruno Barge, 3e Beat Mueller. Circuit technique moyen : 1er Laurent Merat (O’Jura), 2e Jirden Lennart, 3e Daria Niggli. Circuit technique court : 1er Victor Kuznetsov (COLJ), 2e N...

  14. Orienteering club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Course d'orientation Vers les dernières courses de printemps Une centaine de coureurs se sont déplacés sur le site de la Roche Fendue prés de Morez pour gouter à un des 5 parcours proposés par le club du O’Jura. Le terrain était gras mais que peut-on trouver d’autre avec cette météo! Les vainqueurs de chaque circuit sont : Alina Niggli (O’Jura) facile court, Natalja Niggli (O’Jura) facile moyen, Victor Kuznetsov (COLJ) technique court, Yves Rousselot (Balise 25) technique moyen et pour finir François Gonon (O’Jura) avec une victoire haut la main sur le technique long. Il ne reste plus que deux épreuves pour la coupe genevoise de printemps : à savoir samedi 8 juin, course de type longue distance organisée par le club de Lausanne Jorat (COLJ) dans le bois de Seyte sur Mutrux/Concise, inscription de 12h &...

  15. Orienteering Club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Course d'orientation Le coup d’envoi de la coupe genevoise a été donné samedi 31 août dans les bois de Combe Froide à Prémanon. Plus de 150 coureurs avaient fait le déplacement. Les parcours facile court, facile moyen et technique court ont été remportés par des coureurs du club O’Jura - Ulysse Dannecker, Léo Lonchampt, Franck Lonchampt, le technique moyen par Pekka Marti du club Ol Biel Seeland et le technique long par Térence Risse du CA Rosé – également membre de l’équipe nationale suisse des moins de 20 ans. Pour le club du CERN, les meilleures résultats ont été obtenus pas Emese Szunyog sur technique court et Marie Vuitton sur technique moyen avec une 4e place. La prochaine course aura lieu samedi 14 septembre à La Faucille. Le club propose aussi...

  16. Orienteering Club

    CERN Multimedia

    CLUB D'ORIENTATION

    2013-01-01

    Calendrier de la coupe d’automne Le Club d’orientation du CERN, en partenariat avec d’autres clubs de la région, vous propose, pour cette nouvelle coupe d’automne genevoise, une série de 10 courses. Le club du O’Jura donnera le coup d’envoi le samedi 31 août. Les courses s’enchaîneront selon le calendrier suivant : Samedi 31 août : Prémanon (39) - longue distance Samedi 14 septembre : La Faucille (01) - longue distance Samedi 21 septembre : Saint Cergue (VD) - longue distance Samedi 28 septembre : Ballens (VD) - relais Samedi 5 octobre : La Pile (VD) - longue distance Vendredi 11 octobre : Les Evaux (GE) - nocturne Samedi 12 octobre : Grand Jorat, Savigny (VD) - longue distance Samedi 19 octobre : Terrasses de Genève (74) - longue distance Samedi 26 octobre : Prémanon (39) - longue distance Samedi 2 novembre : Bois Tollot (GE) - score - Finale Les &a...

  17. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2012-01-01

    Relais inter-club/Challenge Carlo Milan Samedi dernier, lors de l’épreuve de course d’orientation organisée par le club du O’Jura, le moteur de la discipline était l’esprit d’équipe, puisqu’il était question d’un relais inter-club avec le Challenge Carlo Milan. Les clubs avaient aligné leurs coureurs soit sur le relais technique (trois participants) soit sur le relais facile (deux participants). Côté O’Jura, il fallait noter la participation de François Gonon, champion du monde 2011, côté club du CERN, Marie et Gaëtan Vuitton, jeunes espoirs du club, devaient préparer la piste pour lancer le dernier relayeur. Côté Lausanne-Jorat, il fallait compter sur le très jeune Viktor Kuznetsov. Les 31 équipes engagées n’ont pas m&ea...

  18. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2012-01-01

     Finale de la coupe de printemps   La dernière course d’orientation comptant pour la Coupe de printemps a eu lieu samedi dernier dans le village des Rousses et vers le Fort. Il s’agissait d’un sprint organisé par le club O’Jura. Les temps de course ont avoisiné les 20 minutes que ce soit pour le parcours technique moyen ou technique long. Tous les habitués étaient au rendez-vous pour venir consolider ou améliorer leur place au classement. A l’issue de cette course, le classement général de la Coupe de printemps prenant en compte les 6 meilleurs résultats des 9 courses était établi et les lauréats de chaque catégorie sont les suivants: Circuit technique long : 1er Berni Wehrle, 2e Bruno Barge, 3e Edvins Reisons. Circuit technique moyen : 1er Jean-Bernard Zosso, 2e Cédric Wehrl&...

  19. Orienteering Club

    CERN Multimedia

    Club d'Orientation

    2015-01-01

    Course orientation Finale de la coupe genevoise La série des courses de printemps s’est achevée samedi dernier dans les bois de Bonmont (Vaud) avec une épreuve «one-man-relay» organisée par le club. Le vainqueur du parcours technique  long, Yann Locatelli (Club de Chambéry Savoie) a réalisé les deux boucles comportant 24 balises avec presque 6 minutes d’avance sur le second concurrent Domenico Lepori (Club CARE Vevey). Cette dernière étape était aussi décisive pour la désignation des lauréats de la coupe genevoise de printemps, en comptabilisant les 6 meilleurs résultats sur les 10 épreuves. Le podium officiel était donné par le président du club, L. Jirden, qui profitait de l’occasion pour remercier tous les participants et également tous les...

  20. Orienteering club

    CERN Multimedia

    Club d'orientation

    2013-01-01

    Courses d’orientation Samedi 20 avril, les organisateurs du Club de CO du CERN ont accueilli au Mont Mourex 70 participants qui n’ont pas hésité à venir malgré la forte bise. Berni Wehrle du CO CERN s’est octroyé la première place en 1:04:49 sur le parcours technique long devant Pyry Kettunen du Saynso Juankoski en 1:06:52, la 3e place revenant à Bruno Barge, CO CERN, à 7 secondes. Les autres parcours ont été remportés par : Technique moyen : 1er Jacques Moisset, Chamonix (47:44), 2e Yves Rousselot, Balise 25 Besançon (57:16), 3e Jean-Bernard Zosso, CO CERN (59:28). Technique court : 1er Victor Kuznetsov, COLJ (51:53), 2e Pierrick Collet, CO CERN (1:12:52), 3e Dominique Balay, CO CERN (1:16:04). Pour les parcours facile moyen et facile court, Ralf Nardini et Léa Nicolas, tous deux du CO CERN, terminaient respectivement premier. Voi...

  1. Orienteering club

    CERN Multimedia

    Club d'orientation

    2014-01-01

    Course d'orientation C’est sous un beau soleil samedi 4 octobre que s’est déroulée la 6e étape de la Coupe genevoise d’automne organisée par le club. Plus d’une centaine de concurrents provenant de 7 clubs de CO avaient fait le déplacement pour courir sur un des cinq parcours proposés dans les bois de Trélex-Génolier (VD). Le podium est le suivant : Technique long (5,9 km, 19 postes) : 1er Jurg Niggli, O’Jura (1:00:02); 2e Berni Wehrle, CO CERN (1:06:44); 3e Konrad Ehrbar, COLJ (1:07:08) Technique moyen (4,8 km, 18 postes) : 1er Christophe Vuitton, CO CERN (54:25); 2e J.B. Zosso, CO CERN (1:01:19); 3e Jeremy Wichoud, COLJ (1:06:21) Technique court (3,8 km, 14 postes) : 1er Julien Vuitton, CO CERN (36:19); 2e Vladimir Kuznetsov, COLJ (48:47); 3e Natalia Niggli, O’Jura (50:38) Facile moyen (3,2 km, 11 postes) : 1ère Alina Niggli, O&...

  2. Fabrication and characterization of poly(vinyl alcohol)/carbon nanotube melt-spinning composites fiber

    OpenAIRE

    Zhiqian Yang; Degen Xu; Jianzhong Liu; Jiaping Liu; Lin Li; Lihui Zhang; Jin Lv

    2015-01-01

    A composite fiber based on carbon nanotube (CNT) and poly(vinyl alcohol) (PVA) was prepared by melt-spinning. Structural features and the mechanical performances of the PVA/CNT composite fiber were investigated as a function of draw condition. Initial moduli and tensile strengths of the drawn composite fibers are much higher than those of undrawn composite fiber. It is identified from XRD and 2D XRD that the composite fiber exhibits enhanced crystallinity and orientation degree with increasin...

  3. Phosphorylated DegU Manipulates Cell Fate Differentiation in the Bacillus subtilis Biofilm

    Science.gov (United States)

    Marlow, Victoria L.; Porter, Michael; Hobley, Laura; Kiley, Taryn B.; Swedlow, Jason R.; Davidson, Fordyce A.

    2014-01-01

    Cell differentiation is ubiquitous and facilitates division of labor and development. Bacteria are capable of multicellular behaviors that benefit the bacterial community as a whole. A striking example of bacterial differentiation occurs throughout the formation of a biofilm. During Bacillus subtilis biofilm formation, a subpopulation of cells differentiates into a specialized population that synthesizes the exopolysaccharide and the TasA amyloid components of the extracellular matrix. The differentiation process is indirectly controlled by the transcription factor Spo0A that facilitates transcription of the eps and tapA (tasA) operons. DegU is a transcription factor involved in regulating biofilm formation. Here, using a combination of genetics and live single-cell cytological techniques, we define the mechanism of biofilm inhibition at high levels of phosphorylated DegU (DegU∼P) by showing that transcription from the eps and tapA promoter regions is inhibited. Data demonstrating that this is not a direct regulatory event are presented. We demonstrate that DegU∼P controls the frequency with which cells activate transcription from the operons needed for matrix biosynthesis in favor of an off state. Subsequent experimental analysis led us to conclude that DegU∼P functions to increase the level of Spo0A∼P, driving cell fate differentiation toward the terminal developmental process of sporulation. PMID:24123822

  4. The Structure of Dark Molecular Gas in the Galaxy - I: A Pilot Survey for 18-cm OH Emission Towards $l \\approx 105^{\\deg}, b \\approx +1^{\\deg}$

    CERN Document Server

    Allen, Ronald J; Engelke, Philip D

    2015-01-01

    We report the first results from a survey for 1665, 1667, and 1720 MHz OH emission over a small region of the Outer Galaxy centered at $l \\approx 105.0\\deg , b \\approx +1.0\\deg$ . This sparse, high-sensitivity survey ($\\Delta Ta \\approx \\Delta Tmb \\approx 3.0 - 3.5$ mK rms in 0.55 km/s channels), was carried out as a pilot project with the Green Bank Telescope (GBT, FWHM $\\approx 7.6'$) on a 3 X 9 grid at $0.5\\deg$ spacing. The pointings chosen correspond with those of the existing $^{12}$CO(1-0) CfA survey of the Galaxy (FWHM $\\approx 8.4'$). With 2-hr integrations, 1667 MHz OH emission was detected with the GBT at $\\gtrsim 21$ of the 27 survey positions ($\\geq 78\\%$ ), confirming the ubiquity of molecular gas in the ISM as traced by this spectral line. With few exceptions, the main OH lines at 1665 and 1667 MHz appear in the ratio of 5:9 characteristic of LTE at our sensitivity levels. No OH absorption features are recorded in the area of the present survey, in agreement with the low levels of continuum bac...

  5. Analysis of the thin layer of Galactic warm ionized gas in the range 20 < l < 30 deg, -1.5 < b < +1.5 deg

    CERN Document Server

    Paladini, R; Davies, R D; Giard, M

    2005-01-01

    We present an analysis of the thin layer of Galactic warm ionized gas at an angular resolution ~ 10'. This is carried out using radio continuum data at 1.4 GHz, 2.7 GHz and 5 GHz in the coordinate region 20 < l < 30 deg, -1.5 < b < +1.5 deg. For this purpose, we evaluate the zero level of the 2.7 and 5 GHz surveys using auxiliary data at 2.3 GHz and 408 MHz. The derived zero level corrections are T_{zero}(2.7 GHz)=0.15 +/- 0.06 K and T_{zero}(5 GHz)=0.1 +/- 0.05 K. We separate the thermal (free-free) and non-thermal (synchrotron) component by means of a spectral analysis performed adopting an antenna temperature spectral index -2.1 for the free-free emission, a realistic spatial distribution of indices for the synchrotron radiation and by fitting, pixel-by-pixel, the Galactic spectral index. We find that at 5 GHz, for |b| = 0 deg, the fraction of thermal emission reaches a maximum value of 82%, while at 1.4 GHz, the corresponding value is 68%. In addition, for the thermal emission, the analysis in...

  6. SAS-2 observations of the diffuse gamma radiation in the galactic latitude interval 10 deg absolute b or equal to 90 deg

    Science.gov (United States)

    Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.; Oegelman, H. B.; Oezel, M. E.; Tuemer, T.

    1977-01-01

    An analysis of all of the second small astronomy satellite gamma-ray data for galactic latitudes with the absolute value of b 10 deg has shown that the intensity varies with galactic latitude, being larger near 10 deg than 90 deg. For energies above 100 MeV the gamma-ray data are consistent with a latitude distribution of the form I(b) = C sub 1 + C sub 2/sin b, with the second term being dominant. This result suggests that the radiation above 100 MeV is coming largely from local regions of the galactic disk. Between 35 and 100 MeV, a similar equation is also a good representation of the data, but here the two terms are comparable. These results indicate that the diffuse radiation above 35 MeV consists of two parts, one with a relatively hard galactic component and the other an isotropic, steep spectral component which extrapolates back well to the low energy diffuse radiation. The steepness of the diffuse isotropic component places significant constraints on possible theoretical models of this radiation.

  7. RESEARCH ON THE MOTION OF PARTICLES IN THE TURBULENT PIPE FLOW OF FIBER SUSPENSIONS

    Institute of Scientific and Technical Information of China (English)

    张卫峰; 林建忠

    2004-01-01

    The motion of fibers in turbulent pipe flow was simulated by 3-D integral method based on the slender body theory and simplified model of turbulence. The orientation distribution of fibers in the computational area for different Re numbers was computed. The results which were consistent with the experimental ones show that the fluctuation velocity of turbulence cause fibers to orient randomly. The orientation distributions become broader as the Re number increases. Then the fluctuation velocity and angular velocity of fibers were obtained. Both are affected by the fluctuation velocity of turbulence. The fluctuation velocity intensity of fiber is stronger at longitudinal than at lateral, while it was opposite for the fluctuation angular velocity intensity of fibers. Finally, the spatial distribution of fiber was given. It is obvious that the fiber dispersion is strenghened with the increase of Re numbers.

  8. On the structural features of fiber suspensions in converging channel flow

    Institute of Scientific and Technical Information of China (English)

    林建忠; 张凌新

    2003-01-01

    The structural features of fiber suspensions are dependent on the fiber alignment in the flows. In this work the orientation distribution function and orientation tensors for semi-concentrated fiber suspensions in converging channel flow were calculated, and the evolutions of the fiber alignment and the bulk effective viscosity were analyzed. The results showed that the bulk stress and the effective viscosity were functions of the rate-of-strain tensor and the fiber orientation state; and that the fiber suspensions evolved to steady alignment and tended to concentrate to some preferred directions close to but not same as the directions of local streamlines. The bulk effective viscosity depended on the product of Reynolds number and time. The decrease of effective viscosity near the boundary benefited the increase of the rate of flow. Finally when the fiber alignment went into steady state, the structural features of fiber suspensions were not dependent on the Reynolds number but on the converging channel angle.

  9. Smart polymer fibers with shape memory effect

    Science.gov (United States)

    Ji, Feng Long; Zhu, Yong; Lian Hu, Jin; Liu, Yan; Yeung, Lap-Yan; Dou Ye, Guang

    2006-12-01

    In this study, a series of smart polymer fibers with a shape memory effect were developed. Firstly, a set of shape memory polyurethanes with varying hard-segment content were synthesized. Then, the solutions of the shape memory polyurethanes were spun into fibers through wet spinning. The thin films of the polyurethanes were considered to represent the nature of the polyurethanes. Differential scanning calorimetry tests were performed on both the thin films and the fibers to compare their thermal properties. Wide angle x-ray diffraction and small angle x-ray scattering techniques were applied to investigate the structure of the thin films and the fibers, and the structure change taking place in the spinning process was therefore revealed. The spinning process resulted in the polyurethane molecules being partially oriented in the direction of the fiber axis. The molecular orientation prompted the aggregation of the hard segments and the formation of hard-segment microdomains. The mechanical properties of the fibers were examined through tensile tests. The shape memory effect of the thin films and the fibers was investigated through a series of thermomechanical cyclic tensile tests. It was found that the fibers showed less shape fixity but more shape recovery compared with the thin films. Further investigations revealed that the recovery stress of the fibers was higher than that of the thin films. The smart fibers may exert the recovery force of shape memory polymers to an extreme extent in the direction of the fiber axis and therefore provide a possibility for producing high-performance actuators.

  10. Activities to investigate wavelength-shifting optical fibers

    Science.gov (United States)

    Anderson, Megan; Strong, Denver; Baker, Blane

    2017-07-01

    Understanding principles and operation of optical fibers is important for students of physics due to increased applications of fiber optics in today’s technological world. In an effort to devise new activities to study such fibers, we obtained samples of wavelength-shifting WLS optical fibers, used in construction of research-grade particle detectors. Qualitative experiments in our laboratories examined how these fibers interact with various colors of visible light. From these results, student activities were developed to increase critical thinking in introductory physics courses and to facilitate students’ progression from traditional-classroom to research-oriented settings.

  11. Electrical spin injection and detection in high mobility 2DEG systems

    Science.gov (United States)

    Ciorga, M.

    2016-11-01

    In this review paper we present the current status of research related to the topic of electrical spin injection and detection in two-dimensional electron gas (2DEG) systems, formed typically at the interface between two III-V semiconductor compounds. We discuss both theoretical aspects of spin injection in case of ballistic transport as well as give an overview of available reports on spin injection experiments performed on 2DEG structures. In the experimental part we focus particularly on our recent work on all-semiconductor structures with a 2DEG confined at an inverted GaAs/(Al,Ga)As interface and with a ferromagnetic semiconductor (Ga,Mn)As employed as a source of spin-polarized electrons.

  12. Giovanni Degli Alessandri: i primi anni del direttorato agli Uffizi fra nuovi e vecchi ruoli

    Directory of Open Access Journals (Sweden)

    Chiara Pasquinelli

    2011-11-01

    Full Text Available La figura di Giovanni Degli Alessandri (1765-1830, presidente dell’Accademia di Belle Arti di Firenze e direttore degli Uffizi tra gli anni napoleonici e la Restaurazione di Ferdinando III d’Asburgo-Lorena, è quella di un personaggio chiave nella politica artistica fiorentina, e toscana più in generale. Nel saggio si esaminano i primi anni del suo direttorato alla Galleria, i rapporti con Antonio Canova, il suo ruolo all’interno dell’entourage di Elisa Baciocchi Bonaparte, oltre a considerare alcuni spunti legati al rinnovamento degli Uffizi, nonché la delicata vicenda del passaggio in città di Dominique-Vivant Denon, direttore del Louvre. L’obbiettivo è quello di introdurre elementi di approfondimento relativamente a una figura molto nota ma poco studiata.

  13. A high sensitivity HI survey of the sky at delta < -25 deg Final data release

    CERN Document Server

    Bajaja, E; Larrarte, J J; Morras, R; Poppel, W G L; Kalberla, P M W

    2005-01-01

    We present the final data release of the high sensitivity lambda 21-cm neutral hydrogen survey of the sky south of delta < -25 degr. A total of 50980 positions lying on a galactic coordinate grid with points spaced by (Delta l, Delta b) = ((0.5 deg)/cos b, 0.5 deg) were observed with the 30-m dish of the Instituto Argentino de Radioastronomia (IAR). The angular resolution of the survey is HPBW = 0.5 deg and the velocity coverage spans the interval -450 km/s to +400 km/s (LSR). The velocity resolution is 1.27 km/s and the final rms noise of the entire database is 0.07 K. The data are corrected for stray radiation and converted to brightness temperatures.

  14. Soluble vs. insoluble fiber

    Science.gov (United States)

    Insoluble vs. soluble fiber; Fiber - soluble vs. insoluble ... There are 2 different types of fiber -- soluble and insoluble. Both are important for health, digestion, and preventing diseases. Soluble fiber attracts water and turns to gel during digestion. ...

  15. Photovoltaic fibers

    Science.gov (United States)

    Gaudiana, Russell; Eckert, Robert; Cardone, John; Ryan, James; Montello, Alan

    2006-08-01

    It was realized early in the history of Konarka that the ability to produce fibers that generate power from solar energy could be applied to a wide variety of applications where fabrics are utilized currently. These applications include personal items such as jackets, shirts and hats, to architectural uses such as awnings, tents, large covers for cars, trucks and even doomed stadiums, to indoor furnishings such as window blinds, shades and drapes. They may also be used as small fabric patches or fiber bundles for powering or recharging batteries in small sensors. Power generating fabrics for clothing is of particular interest to the military where they would be used in uniforms and body armor where portable power is vital to field operations. In strong sunlight these power generating fabrics could be used as a primary source of energy, or they can be used in either direct sunlight or low light conditions to recharge batteries. Early in 2002, Konarka performed a series of proof-of-concept experiments to demonstrate the feasibility of building a photovoltaic cell using dye-sensitized titania and electrolyte on a metal wire core. The approach taken was based on the sequential coating processes used in making fiber optics, namely, a fiber core, e.g., a metal wire serving as the primary electrode, is passed through a series of vertically aligned coating cups. Each of the cups contains a coating fluid that has a specific function in the photocell. A second wire, used as the counter electrode, is brought into the process prior to entering the final coating cup. The latter contains a photopolymerizable, transparent cladding which hardens when passed through a UV chamber. Upon exiting the UV chamber, the finished PV fiber is spooled. Two hundred of foot lengths of PV fiber have been made using this process. When the fiber is exposed to visible radiation, it generates electrical power. The best efficiency exhibited by these fibers is 6% with an average value in the 4

  16. Reclutamento e formazione dei poliziotti: il caso degli ufficiali della gendarmeria francese

    Directory of Open Access Journals (Sweden)

    François Dieu

    2007-04-01

    Full Text Available Partendo dal caso degli ufficiali della gendarmeria francese, questo articolo illustra il modo in cui il reclutamento e la formazione possono contribuire, informalmente, alla ripartizione del potere nelle organizzazioni di polizia. Tramite la diversità delle vie di reclutamento si costituisce, di fatto, un vero e proprio sistema di "caste", con una stratificazione degli ufficiali in tre livelli gerarchici, che produce, al di là dei principi meritocratici, delle ineguaglianze manifeste nella ripartizione del potere nell'organizzazione della gendarmeria.

  17. Electrospun Polymer Fibers for Electronic Applications

    Directory of Open Access Journals (Sweden)

    Alessandro Luzio

    2014-01-01

    Full Text Available Nano- and micro- fibers of conjugated polymer semiconductors are particularly interesting both for applications and for fundamental research. They allow an investigation into how electronic properties are influenced by size confinement and chain orientation within microstructures that are not readily accessible within thin films. Moreover, they open the way to many applications in organic electronics, optoelectronics and sensing. Electro-spinning, the technique subject of this review, is a simple method to effectively form and control conjugated polymer fibers. We provide the basics of the technique and its recent advancements for the formation of highly conducting and high mobility polymer fibers towards their adoption in electronic applications.

  18. Tracking White Matter Fiber in Human Brain

    Institute of Scientific and Technical Information of China (English)

    KANGNing; ZHANGJun; EricSCarlson

    2004-01-01

    A new approach for noninvasively tracing brain white matter fiber tracts is presented using diffusion tensor magnetic resonance imaging (DT-MRI) data. This technique is based on successive anisotropic diffusion simulations over the human brain, which are utilized to construct three dimensional diffusion fronts. The fiber pathways are determined by evaluating the distance and orientation from fronts to their corresponding diffusion seeds. Real DT-MRI data are used to demonstrate the tracking scheme. It is shown that several major white matter fiber pathways can be reproduced noninvasively, with the tract branching being allowed. Since the diffusion simulation,which is a truly physical phenomenon reflecting the underlying architecture of cerebral tissues, makes full use of the entire diffusion tensor data, the proposed approach is expected to enhance robustness and reliability of the DT-MRI based fiber tracking techniques in white matter fiber reconstruction.

  19. Curved Piezoelectric Actuators for Stretching Optical Fibers

    Science.gov (United States)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    Assemblies containing curved piezoceramic fiber composite actuators have been invented as means of stretching optical fibers by amounts that depend on applied drive voltages. Piezoceramic fiber composite actuators are conventionally manufactured as sheets or ribbons that are flat and flexible, but can be made curved to obtain load-carrying ability and displacement greater than those obtainable from the flat versions. In the primary embodiment of this invention, piezoceramic fibers are oriented parallel to the direction of longitudinal displacement of the actuators so that application of drive voltage causes the actuator to flatten, producing maximum motion. Actuator motion can be transmitted to the optical fiber by use of hinges and clamp blocks. In the original application of this invention, the optical fiber contains a Bragg grating and the purpose of the controlled stretching of the fiber is to tune the grating as part of a small, lightweight, mode-hop-free, rapidly tunable laser for demodulating strain in Bragg-grating strain-measurement optical fibers attached to structures. The invention could also be used to apply controllable tensile force or displacement to an object other than an optical fiber.

  20. Fiber resources

    Science.gov (United States)

    P. J. Ince

    2004-01-01

    In economics, primary inputs or factors of production define the term ‘resources.’ Resources include land resources (plants, animals, and minerals), labor, capital, and entrepreneurship. Almost all pulp and paper fiber resources are plant materials obtained from trees or agricultural crops. These resources encompass plant materials harvested directly from the land (...

  1. Orientation statistics of non-spherical particles sedimenting in turbulence

    Science.gov (United States)

    Kramel, Stefan; Tierney, Lydia; Rees, Wyatt; Voth, Greg A.; Menon, Udayshankar; Roy, Anubhab; Koch, Donald L.

    2016-11-01

    We study the sedimentation of non-spherical particles in turbulence. The particle orientation is determined by a competition between inertial torques causing a preferential alignment and turbulence randomizing the orientation. The relative importance is quantified by a settling number SF defined as the ratio of the tumbling-rate from inertial torques and from turbulence. The experiments focus on the orientation statistics of particles formed from several slender arms, including fibers and particles with three arms in planar symmetry (triads), which allows us to study alignment of both fibers and disk-like particles. We measure the time-resolved 3D orientations of the particles along with the fluid velocity field around them in a vertical water tunnel. An active jet array with 40 individually controllable jets enables us to adjust the turbulence intensity and observe the transition from strongly aligned particles to randomized orientations as SF is decreased. Results are compared to simulations and theory based on slender body theory.

  2. Piezoelectric polymer and ceramic ultrafine fibers for piezocomposite films

    OpenAIRE

    Yördem, Sinan Onur; Yordem, Sinan Onur; Papila, Melih; Menceloğlu, Yusuf Z.; Menceloglu, Yusuf Z.; Öğüt, Erdem; Ogut, Erdem; Gülleroğlu, Mert; Gulleroglu, Mert

    2006-01-01

    This paper describes the process development and characterization of Poly(vinylidene fluoride) (PVDF) films and fiber mats and Zinc Oxide (ZnO) fibers as ingredients of a future piezo-composite film. The polymer system PVDF is electroactive and processed here by solution casting and annealing to form active films. Electrospinning of PVDF and Poly(vinyl alcohol)-Zincacetate precursor solutions were also under investigation to produce randomly oriented polymer and ceramic fiber mats, respective...

  3. Magnetically Aligned HI Fibers and the Rolling Hough Transform

    OpenAIRE

    Clark, S E; Peek, J. E. G.; Putman, M. E.

    2013-01-01

    We present observations of a new group of structures in the diffuse Galactic ISM: slender, linear HI features we dub "fibers" that extend for many degrees at high Galactic latitude. To characterize and measure the extent and strength of these fibers, we present the Rolling Hough Transform (RHT), a new machine vision method for parameterizing the coherent linearity of structures in the image plane. With this powerful new tool we show the fibers are oriented along the interstellar magnetic fiel...

  4. Symmetric Euler orientation representations for orientational averaging.

    Science.gov (United States)

    Mayerhöfer, Thomas G

    2005-09-01

    A new kind of orientation representation called symmetric Euler orientation representation (SEOR) is presented. It is based on a combination of the conventional Euler orientation representations (Euler angles) and Hamilton's quaternions. The properties of the SEORs concerning orientational averaging are explored and compared to those of averaging schemes that are based on conventional Euler orientation representations. To that aim, the reflectance of a hypothetical polycrystalline material with orthorhombic crystal symmetry was calculated. The calculation was carried out according to the average refractive index theory (ARIT [T.G. Mayerhöfer, Appl. Spectrosc. 56 (2002) 1194]). It is shown that the use of averaging schemes based on conventional Euler orientation representations leads to a dependence of the result from the specific Euler orientation representation that was utilized and from the initial position of the crystal. The latter problem can be overcome partly by the introduction of a weighing factor, but only for two-axes-type Euler orientation representations. In case of a numerical evaluation of the average, a residual difference remains also if a two-axes type Euler orientation representation is used despite of the utilization of a weighing factor. In contrast, this problem does not occur if a symmetric Euler orientation representation is used as a matter of principle, while the result of the averaging for both types of orientation representations converges with increasing number of orientations considered in the numerical evaluation. Additionally, the use of a weighing factor and/or non-equally spaced steps in the numerical evaluation of the average is not necessary. The symmetrical Euler orientation representations are therefore ideally suited for the use in orientational averaging procedures.

  5. Degradation of PsbO by the Deg protease HhoA Is thioredoxin dependent.

    Directory of Open Access Journals (Sweden)

    Irma N Roberts

    Full Text Available The widely distributed members of the Deg/HtrA protease family play an important role in the proteolysis of misfolded and damaged proteins. Here we show that the Deg protease rHhoA is able to degrade PsbO, the extrinsic protein of the Photosystem II (PSII oxygen-evolving complex in Synechocystis sp. PCC 6803 and in spinach. PsbO is known to be stable in its oxidized form, but after reduction by thioredoxin it became a substrate for recombinant HhoA (rHhoA. rHhoA cleaved reduced eukaryotic (specifically, spinach PsbO at defined sites and created distinct PsbO fragments that were not further degraded. As for the corresponding prokaryotic substrate (reduced PsbO of Synechocystis sp. PCC 6803, no PsbO fragments were observed. Assembly to PSII protected PsbO from degradation. For Synechocystis sp. PCC 6803, our results show that HhoA, HhoB, and HtrA are localized in the periplasma and/or at the thylakoid membrane. In agreement with the idea that PsbO could be a physiological substrate for Deg proteases, part of the cellular fraction of the three Deg proteases of Synechocystis sp. PCC 6803 (HhoA, HhoB, and HtrA was detected in the PSII-enriched membrane fraction.

  6. The air oxidation behavior of lanthanum ion implanted zirconium at 500 deg. C

    CERN Document Server

    Peng, D Q; Chen, X W; Zhou, Q G

    2003-01-01

    The beneficial effect of lanthanum ion implantation on the oxidation behavior of zirconium at 500 deg. C has been studied. Zirconium specimens were implanted by lanthanum ions using a MEVVA source at energy of 40 keV with a fluence range from 1x10 sup 1 sup 6 to 1x10 sup 1 sup 7 ions/cm sup 2 at maximum temperature of 130 deg. C, The weight gain curves were measured after being oxidized in air at 500 deg. C for 100 min, which showed that a significant improvement was achieved in the oxidation behavior of zirconium ion implanted with lanthanum compared with that of the as-received zirconium. The valence of the oxides in the scale was analyzed by X-ray photoemission spectroscopy; and then the depth distributions of the elements in the surface of the samples were obtained by Auger electron spectroscopy. Glancing angle X-ray diffraction at 0.3 deg. incident angles was employed to examine the modification of its phase transformation because of the lanthanum ion implantation in the oxide films. It was obviously fou...

  7. Exploring a possible origin of a 14 deg y-normal spin tilt at RHIC polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-06-15

    A possible origin of a 14 deg y-normal spin n0 tilt at the polarimeter is in snake angle defects. This possible cause is investigated by scanning the snake axis angle µ, and the spin rotation angle at the snake, φ, in the vicinity of their nominal values.

  8. A Byzantine chant collection from Sicily: a collaboration between Copenhagen and Piana degli Albanesi (Palermo)

    DEFF Research Database (Denmark)

    Sanfratello, Giuseppe

    2016-01-01

    The aim of this paper is to give an account of the collaboration between a collector of the Byzantine chant tradition of Piana degli Albanesi (Palermo) in Sicily, namely fr. Bartolomeo Di Salvo, and the editorial board of the Monumenta Musicae Byzantinae, i.e. an institution under the aegis......, Collections, Ethnomusicology, Critical edition, Monumenta Musicae Byzantinae (MMB)...

  9. Phosphorylation of DegU is essential for activation of amyE expression in Bacillus subtilis

    Indian Academy of Sciences (India)

    Monica Gupta; K Krishnamurthy Rao

    2014-12-01

    Alpha ()-amylase (amyE) is one of the major exo-enzymes secreted by Bacillus subtilis during the post-exponential phase. The DegS-DegU two-component system regulates expression of majority of post-exponentially expressed genes in B. subtilis. It has been demonstrated that varying levels of the phosphorylated form of DegU (DegU-P) control different cellular processes. Exo-protease production is observed when effective concentration of DegU-P rises in the cell, whereas swarming motility is favoured at very low amounts of DegU-P. In this study we show that like other exo-proteases, expression of amyE is positively regulated by increase in DegU-P levels in the cell. We also demonstrate that residues at the DNA-binding helix-turn-helix (HTH) motif of DegU are necessary for the amyE expression. This observation is further reinforced by demonstrating the direct interaction of DegU on amyE promoter.

  10. AromaDeg, a novel database for phylogenomics of aerobic bacterial degradation of aromatics.

    Science.gov (United States)

    Duarte, Márcia; Jauregui, Ruy; Vilchez-Vargas, Ramiro; Junca, Howard; Pieper, Dietmar H

    2014-01-01

    Understanding prokaryotic transformation of recalcitrant pollutants and the in-situ metabolic nets require the integration of massive amounts of biological data. Decades of biochemical studies together with novel next-generation sequencing data have exponentially increased information on aerobic aromatic degradation pathways. However, the majority of protein sequences in public databases have not been experimentally characterized and homology-based methods are still the most routinely used approach to assign protein function, allowing the propagation of misannotations. AromaDeg is a web-based resource targeting aerobic degradation of aromatics that comprises recently updated (September 2013) and manually curated databases constructed based on a phylogenomic approach. Grounded in phylogenetic analyses of protein sequences of key catabolic protein families and of proteins of documented function, AromaDeg allows query and data mining of novel genomic, metagenomic or metatranscriptomic data sets. Essentially, each query sequence that match a given protein family of AromaDeg is associated to a specific cluster of a given phylogenetic tree and further function annotation and/or substrate specificity may be inferred from the neighboring cluster members with experimentally validated function. This allows a detailed characterization of individual protein superfamilies as well as high-throughput functional classifications. Thus, AromaDeg addresses the deficiencies of homology-based protein function prediction, combining phylogenetic tree construction and integration of experimental data to obtain more accurate annotations of new biological data related to aerobic aromatic biodegradation pathways. We pursue in future the expansion of AromaDeg to other enzyme families involved in aromatic degradation and its regular update. Database URL: http://aromadeg.siona.helmholtz-hzi.de

  11. Pluralità di etnie, di religioni, di Stati in Medio-oriente; il terrorismo islamico

    Directory of Open Access Journals (Sweden)

    Vittorio Parlato

    2017-05-01

    Full Text Available SOMMARIO: 1. Le ripartizioni islamiche – 2. La realtà cristiana mediorientale - 3. Gli Yazidi - 4. Chiese etniche e realtà statuali in Medio-oriente – 5. Il sistema degli statuti personali - 6. Valutazione negativa da parte dell'Islam della laicità dello Stato - 7. Irrealizzabilità di uno stato laico in Medio-oriente - 8. Atti terroristici e fondamentalismo islamico. È guerra di religione?

  12. Influence of crystal-orientation effects on pulse-shape-based identification of heavy-ions stopped in silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bardelli, L. [University of Florence (Italy); I.N.F.N. Sezione di Firenze (Italy)], E-mail: bardelli@fi.infn.it; Bini, M. [University of Florence (Italy); I.N.F.N. Sezione di Firenze (Italy); Casini, G. [I.N.F.N. Sezione di Firenze (Italy); Pasquali, G.; Poggi, G. [University of Florence (Italy); I.N.F.N. Sezione di Firenze (Italy); Barlini, S. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay cedex (France); Becla, A. [Jagiellonian University, Institute of Physics, Reymonta 4, 30-059 Krakow (Poland); Berjillos, R. [Departamento de Fisica Aplicada, Universidad de Huelva, E-21071 Huelva (Spain); Borderie, B. [Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay cedex (France); Bougault, R. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Bruno, M. [University of Bologna (Italy); I.N.F.N. Sezione di Bologna (Italy); Cinausero, M. [I.N.F.N. Laboratori Nazionali di Legnaro (Italy); D' Agostino, M.; De Sanctis, J. [University of Bologna (Italy); I.N.F.N. Sezione di Bologna (Italy); Duenas, J.A. [Departamento de Fisica Aplicada, Universidad de Huelva, E-21071 Huelva (Spain); Edelbruck, P. [Institut de Physique Nucleaire, CNRS/IN2P3, Universite Paris-Sud 11, F-91406 Orsay cedex (France); Geraci, E. [University of Bologna (Italy); I.N.F.N. Sezione di Bologna (Italy); Gramegna, F. [I.N.F.N. Laboratori Nazionali di Legnaro (Italy); Kordyasz, A. [Heavy Ion Laboratory, Warsaw University, Pasteura 5a, 02-093 Warsaw (Poland); Kozik, T. [Jagiellonian University, Institute of Physics, Reymonta 4, 30-059 Krakow (Poland)] (and others)

    2009-07-01

    Current and charge signals have been collected for Se ions at 408 MeV, S at 160 MeV and Ni at 703 MeV, all stopped in silicon detectors. Some detectors were cut 0 deg. off the <111> axis and some off the <100> axis. Important effects on the shape of the silicon current and charge signals have been observed, depending on the orientation of the impinging ion relative to the crystal axes and planes. A degradation of the energy and risetime resolution of about a factor {approx}3 with respect to the measured optimal values (for example 7 deg. off-axis orientation) is observed for ion impinging directions close to crystal axes and/or planes, i.e. the common scenario for normal incidence on 0 deg. cut detectors. For Pulse Shape Analysis applications, the necessity of using such 'random' oriented silicon detectors is demonstrated.

  13. Thinking in Orienteering.

    Science.gov (United States)

    Johansen, Bjorn Tore

    1997-01-01

    A think-aloud technique, in which 20 orienteers verbalized their exact thoughts during orienteering, was used to examine the phenomenon of cognition during orienteering. Results indicate that orienteering is experienced as a task to be accomplished, a physical movement, and a dynamic process, and that thinking involves attuning perceptions to…

  14. Thermal conductivity, electrical conductivity and specific heat of copper-carbon fiber composite

    Science.gov (United States)

    Kuniya, Keiichi; Arakawa, Hideo; Kanai, Tsuneyuki; Chiba, Akio

    1988-01-01

    A new material of copper/carbon fiber composite is developed which retains the properties of copper, i.e., its excellent electrical and thermal conductivity, and the property of carbon, i.e., a small thermal expansion coefficient. These properties of the composite are adjustable within a certain range by changing the volume and/or the orientation of the carbon fibers. The effects of carbon fiber volume and arrangement changes on the thermal and electrical conductivity, and specific heat of the composite are studied. Results obtained are as follows: the thermal and electrical conductivity of the composite decrease as the volume of the carbon fiber increases, and were influenced by the fiber orientation. The results are predictable from a careful application of the rule of mixtures for composites. The specific heat of the composite was dependent, not on fiber orientation, but on fiber volume. In the thermal fatigue tests, no degradation in the electrical conductivity of this composite was observed.

  15. Hi-GAL, the Herschel infrared Galactic Plane Survey: photometric maps and compact source catalogues. First data release for Inner Milky Way: +68{\\deg}> l > -70{\\deg}

    CERN Document Server

    Molinari, S; Elia, D; Pestalozzi, M; Traficante, A; Pezzuto, S; Swinyard, B M; Noriega-Crespo, A; Bally, J; Moore, T J T; Plume, R; Zavagno, A; di Giorgio, A M; Liu, S J; Pilbratt, G L; Mottram, J C; Russeil, D; Piazzo, L; Veneziani, M; Benedettini, M; Calzoletti, L; Faustini, F; Natoli, P; Piacentini, F; Merello, M; Palmese, A; Del Grande, R; Polychroni, D; Rygl, K L J; Polenta, G; Barlow, M J; Bernard, J -P; Martin, P G; Testi, L; Ali, B; Andrè, P; Beltrán, M T; Billot, N; Brunt, C; Carey, S; Cesaroni, R; Compiègne, M; Eden, D; Fukui, Y; Garcia-Lario, P; Hoare, M G; Huang, M; Joncas, G; Lim, T L; Lord, S D; Martinavarro-Armengol, S; Motte, F; Paladini, R; Paradis, D; Peretto, N; Robitaille, T; Schilke, P; Schneider, N; Schulz, B; Sibthorpe, B; Strafella, F; Thompson, M A; Umana, G; Ward-Thompson, D; Wyrowski, F

    2016-01-01

    (Abridged) We present the first public release of high-quality data products (DR1) from Hi-GAL, the {\\em Herschel} infrared Galactic Plane Survey. Hi-GAL is the keystone of a suite of continuum Galactic Plane surveys from the near-IR to the radio, and covers five wavebands at 70, 160, 250, 350 and 500 micron, encompassing the peak of the spectral energy distribution of cold dust for 8 l > -70{\\deg} in a |b|<1{\\deg} latitude strip. Photometric maps have been produced with the ROMAGAL pipeline, that optimally capitalizes on the excellent sensitivity and stability of the bolometer arrays of the {\\em Herschel} PACS and SPIRE photometric cameras, to deliver images of exquisite quality and dynamical range, absolutely calibrated with {\\em Planck} and {\\em IRAS}, and recovering extended emission at all wavelengths and all spatial scales. The compact source catalogues have been generated with the CuTEx algorithm, specifically developed to optimize source detection and extraction in the extreme conditions of intens...

  16. Cardiac fiber inpainting using cartan forms

    DEFF Research Database (Denmark)

    Puize, Emmanuel; Lombaert, Herve; Sporring, Jon

    2013-01-01

    Recent progress in diffusion imaging has lead to in-vivo acquisitions of fiber orientation data in the beating heart. Current methods are however limited in resolution to a few short-axis slices. For this particular application and others where the diffusion volume is subsampled, partial or even...

  17. Effect of head pitch and roll orientations on magnetically induced vertigo.

    Science.gov (United States)

    Mian, Omar S; Li, Yan; Antunes, Andre; Glover, Paul M; Day, Brian L

    2016-02-15

    Lying supine in a strong magnetic field, such as in magnetic resonance imaging scanners, can induce a perception of whole-body rotation. The leading hypothesis to explain this invokes a Lorentz force mechanism acting on vestibular endolymph that acts to stimulate semicircular canals. The hypothesis predicts that the perception of whole-body rotation will depend on head orientation in the field. Results showed that the direction and magnitude of apparent whole-body rotation while stationary in a 7 T magnetic field is influenced by head orientation. The data are compatible with the Lorentz force hypothesis of magnetic vestibular stimulation and furthermore demonstrate the operation of a spatial transformation process from head-referenced vestibular signals to Earth-referenced body motion. High strength static magnetic fields are known to induce vertigo, believed to be via stimulation of the vestibular system. The leading hypothesis (Lorentz forces) predicts that the induced vertigo should depend on the orientation of the magnetic field relative to the head. In this study we examined the effect of static head pitch (-80 to +40 deg; 12 participants) and roll (-40 to +40 deg; 11 participants) on qualitative and quantitative aspects of vertigo experienced in the dark by healthy humans when exposed to the static uniform magnetic field inside a 7 T MRI scanner. Three participants were additionally examined at 180 deg pitch and roll orientations. The effect of roll orientation on horizontal and vertical nystagmus was also measured and was found to affect only the vertical component. Vertigo was most discomforting when head pitch was around 60 deg extension and was mildest when it was around 20 deg flexion. Quantitative analysis of vertigo focused on the induced perception of horizontal-plane rotation reported online with the aid of hand-held switches. Head orientation had effects on both the magnitude and the direction of this perceived rotation. The data suggest

  18. Environmental fatigue behaviors of wrought and cast stainless steels in 310 .deg. C Deoxygenated Water

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Pyung Yeon

    2011-02-15

    Environmental fatigue behaviors of wrought type 316LN stainless steel and cast CF8M stainless steel were investigated. LCF tests were performed at fixed strain rate of 0.04%/s with 0.4%, 0.6%, 0.8%, 1.0% strain amplitudes in 310 .deg. C deoxygenated water environment. In addition, to analyze microstructure effect on fatigue behavior, low cycle fatigue tests in air environment were performed at fixed strain rate of 0.4%/s, 0.04%/s with 0.4%, 0.8% strain amplitudes. It was shown that the low cycle fatigue life of CF8M in a 310 .deg. C deoxygenated water environment was slightly longer than that of 316LN. On the other hand, the low cycle fatigue life of CF8M in a 310 .deg. C air environment was slightly shorter than that of 316LN or was similar with that of 316LN. Through OM observation and phase image analysis, it was confirmed that the ferrite content of CF8M tested in a 310 .deg. C deoxygenated water environment was larger than that of CF8M tested in a 310 .deg. C air environment. It was shown that the ferrite phase fraction of CF8M tested in 310 .deg. C deoxygenated water environment was approximately 26∼28% and that of CF8M tested in air environment was approximately 10∼12%. The difference of ferrite content in CF8M results in superior tensile properties as higher ferrite content. Furthermore, the difference of ferrite content in CF8M might be the cause of different result of fatigue life between CF8M and 316LN depending on environment. In this study, focused on CF8M having 26∼28% ferrite content, to understand the causes of these differences in a 310 .deg. C deoxygenated water environment, fracture surface and crack morphology were observed. And material factors like microstructure, mechanical properties factors like stress behavior during fatigue life, factors by environmentally assisted cracking (EAC) like hydrogen induced cracking (HIC) and chemical compositions of both materials were analyzed. Mainly in a 310 .deg. C deoxygenated water environment, the

  19. Wind-tunnel force and flow visualization data at Mach numbers from 1.6 to 4.63 for a series of bodies of revolution at angles of attack from minus 4 deg to 60 deg

    Science.gov (United States)

    Landrum, E. J.; Babb, C. D.

    1979-01-01

    Flow visualization and force data for a series of six bodies of revolution are presented without analysis. The data were obtained in the Langley Unitary Plan wind tunnel for angles of attack from -4 deg to 60 deg. The Reynolds number used for these tests was 6,600,000 per meter.

  20. Pourbaix diagrams for the system copper-chlorine at 5-100 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Beverskog, B. [Studsvik Material AB, Nykoeping (Sweden); Puigdomenech, I. [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    1998-04-01

    Pourbaix diagrams for the copper-chlorine system in the temperature interval 5-100 deg C have been revised. Predominance diagrams for dissolved copper containing species have also been calculated. Two different total concentrations of each dissolved element, 10{sup -4} and 10{sup -6} molal for copper and 0.2 and 1.5 molal for chlorine have been used in the calculations. Chloride is the predominating chlorine species in aqueous solutions. Presence of chloride increases the corrosion regions of copper at the expense of the immunity and passivity regions in the Pourbaix diagrams. CuCl{sub 2} {center_dot} 3Cu(OH){sub 2} is the only copper-chloride solid phase that forms at the concentrations of chlorine studied. However, its stability area decreases with increasing temperature. The ion CuCl{sub 2}{sup -} predominates at all temperatures at [Cl(aq)]{sub tot}=0.2 molal and this reduces the immunity and passivity areas. A corrosion region exists between the immunity and passivity regions at 100 deg C at [Cu(aq)]{sub tot}=10{sup -6} and [Cl(aq)]{sub tot}=0.2 molal. At the chlorine concentration of 1.5 molal the corrosion region exists in the whole temperature range investigated. The ion CuCl{sub 3}{sup 2-} predominates at 5-25 and 100 deg C, while CuCl{sub 2}{sup -} predominates at 50-80 deg C at [Cl(aq)]{sub tot=}1-5 molal. A copper concentration of 10{sup -4} molal reduces the corrosion areas due to expansion of the immunity and passivity areas. However, a corrosion region still exists between the immunity and passivity regions at all investigated temperatures at pH{sub {Tau}}<9.5 and 1.5 molal chloride concentration. According to our calculations the copper canisters in the deep nuclear waste repository should not corrode at the copper concentration of 10{sup -6} molal and the chloride concentration of 0.2 molal. However, at 80-100 deg C the equilibrium potentials postulated for the Swedish nuclear repository are dangerously close to a corrosion situation. According to

  1. Book review, Igiene e Tecnologie degli Alimenti di Origine Animale Giampaolo Colavita (a cura di

    Directory of Open Access Journals (Sweden)

    Manuel Graziani

    2008-09-01

    Full Text Available Igiene e Tecnologie degli Alimenti di Origine Animale si avvale del contributo di 33 autori, tutti soci dell’Associazione Italiana Veterinari Igienisti (AIVI, che garantiscono l’appropriata trattazione di una materia estremamente vasta e dinamica. Il manuale nasce da un’iniziativa finalizzata alla realizzazione di un testo che rifletta e possa soddisfare le esigenze didattiche degli insegnamenti di un’ampia serie di materie universitarie: Igiene e Tecnologie degli Alimenti di Origine Animale della Facoltà di Medicina Veterinaria, di Agraria, nei corsi di Scienze e Tecnologie Alimentari, di Scienze e Tecnologie delle Produzioni Animali, nel corso di laurea in Tecniche della Prevenzione nell’ambiente e nei Luoghi di Lavoro, nonché in altri corsi di studio dove si insegnano le discipline relative all’igiene e alla sicurezza degli alimenti.Sono stati trattati gran parte degli alimenti di origine animale, i prodotti a base di carne, il latte e i prodotti derivati, i prodotti della pesca freschi e trasformati, i prodotti dell’alveare, le uova e gli ovoprodotti. Di particolare interesse appare il capitolo riguardante la diagnostica analitica degli alimenti, considerato che le moderne metodologie analitiche risultano fondamentali per affrontare le tematiche legate all’igiene e alla sicurezza alimentare.Il volume ha una finalità prevalentemente didattica ma è comunque rivolto a tutti coloro che operano nel campo dell’Igiene e delle Tecnologie Alimentari. Infatti, visti gli argomenti trattati come le tossinfezioni e le intossicazioni alimentari, la conservazione, il confezionamento e l’etichettatura dei prodotti alimentari, anche i professionisti del settore possono trarre dal testo elementi utili per la loro attività. Per esempio argomenti quali l’analisi del rischio, le attività di audit ed i sistemi di accreditamento e di certificazione sono particolarmente utili per chi opera nelle Aziende Sanitarie Locali e negli Istituti

  2. Understanding and overcoming shear alignment of fibers during extrusion.

    Science.gov (United States)

    Martin, Joshua J; Riederer, Michael S; Krebs, Melissa D; Erb, Randall M

    2015-01-14

    Fiber alignment is the defining architectural characteristic of discontinuous fiber composites and is dictated by shear-dominated processing techniques including flow-injection molding, tape-casting, and mold-casting. However, recent colloidal assembly techniques have started to employ additional forces in fiber suspensions that have the potential to change the energy landscape of the shear-dominated alignment in conditions of flow. In this paper, we develop an energetics model to characterize the shear-alignment of rigid fibers under different flow conditions in the presence of magnetic colloidal alignment forces. We find that these colloidal forces can be sufficient to manipulate the energetic landscape and obtain tunable fiber alignment during flow within even small geometries, such as capillary flow. In most conditions, these colloidal forces work to freeze the fiber orientation during flow and prevent the structure disrupting phenomenon of Jeffrey's orbits that has been accepted to rule fiber suspensions under simple shear flow.

  3. STRUCTURAL INVESTIGATIONS OF VARIOUS COTTON FIBERS AND COTTON CELLULOSES

    Directory of Open Access Journals (Sweden)

    Michael Ioelovich

    2008-02-01

    Full Text Available Macro- and crystalline structure, as well as chemical composition of fibers related to various types and sorts of Israeli cottons, both white and naturally colored, were investigated. The differences in structural parameters and chemical compositions of the cotton fibers were evaluated. Samples of cotton of the “Pima”-type had long, thin and strong fibers with highly ordered supermolecular structure. Fibers of middle-long and hybrid cottons had some lower-ordered structural organization in comparison to long-length cotton, while fibers of naturally colored cotton were characterized with disordered supermolecular and crystalline structure. Dependence of tensile strength on orientation of nano-fibrils towards the fiber axis was found. Conditions of cellulose isolation from the different cotton fibers were studied. Structural characteristics of isolated cotton celluloses and obtained MCC are discussed.

  4. Electrospun Nanofiber Scaffolds with Gradations in Fiber Organization

    Science.gov (United States)

    Khandalavala, Karl; Jiang, Jiang; Shuler, Franklin D.; Xie, Jingwei

    2015-01-01

    The goal of this protocol is to report a simple method for generating nanofiber scaffolds with gradations in fiber organization and test their possible applications in controlling cell morphology/orientation. Nanofiber organization is controlled with a new fabrication apparatus that enables the gradual decrease of fiber organization in a scaffold. Changing the alignment of fibers is achieved through decreasing deposition time of random electrospun fibers on a uniaxially aligned fiber mat. By covering the collector with a moving barrier/mask, along the same axis as fiber deposition, the organizational structure is easily controlled. For tissue engineering purposes, adipose-derived stem cells can be seeded to these scaffolds. Stem cells undergo morphological changes as a result of their position on the varied organizational structure, and can potentially differentiate into different cell types depending on their locations. Additionally, the graded organization of fibers enhances the biomimicry of nanofiber scaffolds so they more closely resemble the natural orientations of collagen nanofibers at tendon-to-bone insertion site compared to traditional scaffolds. Through nanoencapsulation, the gradated fibers also afford the possibility to construct chemical gradients in fiber scaffolds, and thereby further strengthen their potential applications in fast screening of cell-materials interaction and interfacial tissue regeneration. This technique enables the production of continuous gradient scaffolds, but it also can potentially produce fibers in discrete steps by controlling the movement of the moving barrier/mask in a discrete fashion. PMID:25938562

  5. Engineering of silicon-based ceramic fibers: Novel SiTaC(O) ceramic fibers prepared from polytantalosilane

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z., E-mail: xiezhengfang@163.com [State Key Laboratory of Advanced Ceramic Fibers and Composites, National University of Defense Technology, Changsha 410073 (China); Cao, S.; Wang, J. [State Key Laboratory of Advanced Ceramic Fibers and Composites, National University of Defense Technology, Changsha 410073 (China); Yan, X. [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Bernard, S., E-mail: Samuel.Bernard@univ-lyon1.fr [Laboratoire des Multimateriaux et Interfaces (UMR CNRS 5615), Universite de Lyon, Universite Lyon1, 43 bd du 11 Novembre 1918, 69622 Villeurbanne Cedex (France); Miele, P. [Laboratoire des Multimateriaux et Interfaces (UMR CNRS 5615), Universite de Lyon, Universite Lyon1, 43 bd du 11 Novembre 1918, 69622 Villeurbanne Cedex (France)

    2010-10-15

    Research highlights: {yields} This paper reports the preparation and characterization of a novel variety of silicon-based ceramic fibers. {yields} In the present paper, we provide a detailed picture of the preparation process of SiTaC(O) ceramic fibers from a polytantalosilane. {yields} We have fully characterized the polymer by FT-IR, NMR, chemical composition, GPC and TGA as well as the chemical composition, the structure, the texture, and the mechanical properties of the ceramic fibers by XPS, SEM, X-ray diffraction (XRD), and mechanical tests. - Abstract: A novel variety of silicon-based ceramic fibers has been prepared from a preceramic organosilicon polymers called polytantalocarbosilane (PTaCS). This melt-spinnable polymer has been synthesized by thermally induced reactions between tantalum (V) tetraethoxyacetylacetonate (Ta(Acac)(OEt){sub 4}) and polysilacarbosilane (PSCS). The polymer in which [-Si-C-]{sub n} chains are crosslinked via Ta-containing bridges as identified by infrared spectroscopy, XPS and NMR, is decomposed in high ceramic yield (76%) and can be spun in the molten state into fibers to be cured in air then pyrolyzed in flowing nitrogen at 1200 deg. C into amorphous SiTaC(O) fibers. Complete characterization of this new generation of silicon-based ceramic fibers was made based on mechanical tests, XRD and SEM. These fibers exhibit relatively good mechanical properties and excellent high-temperature stability with good oxidation resistance.

  6. Il ruolo degli arbëreshë nella messa a punto del modello albanese di rapporti tra le comunità religiose e lo Stato

    Directory of Open Access Journals (Sweden)

    Giovanni Cimbalo

    2014-05-01

    Full Text Available Il contributo, sottoposto a valutazione, riproduce il testo della Comunicazione presentata alla Konferencë Shkencore Ndërkombëtare Albanologjike, Një rilindje para Rilindjes (Gjirokastër, 22 maj 2013 con il titolo albanese Roli i arbëreschë në zhvillimin e modelit shqiptar të marrëdhënieve ndërmjet bashkësive fetare dhe shtetit, ed è destinata alla pubblicazione negli Atti.SOMMARIO: 1. Caratteristiche dell’insediamento delle popolazioni arbëreshë in Italia - 2. Il contributo del pluralismo religioso nella fondazione dello Stato albanese - 3. L’uso degli arbëreshë per l’espansione della Chiesa cattolica a Oriente: un progetto abortito - 4. Considerazioni conclusive.

  7. Understanding political market orientation

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Henneberg, Stephan C.

    This article develops a conceptual framework and measurement model of political market orientation that consists of attitudinal and behavioural constructs. The article reports on perceived relationships among different behavioral aspects of political market orientation and the attitudinal influen......, a more surprising result is the inconclusive effect of a voter orientation on market-oriented behaviours. The article discusses the findings in the context of the existing literature in political marketing and commercial market orientation.......This article develops a conceptual framework and measurement model of political market orientation that consists of attitudinal and behavioural constructs. The article reports on perceived relationships among different behavioral aspects of political market orientation and the attitudinal...... influences of such behavior. The study includes structural equation modeling to investigate several propositions. While the results show that political parties need to focus on several different aspects of market-oriented behavior, especially using an internal and external orientation as cultural antecedents...

  8. Glass-clad semiconductor core optical fibers

    Science.gov (United States)

    Morris, Stephanie Lynn

    ; experimental results show a decrease in fiber core oxygen content in the fibers drawn with the tailored glass composition. In a further attempt to reduce the presence of oxide species in the core, a reactive molten core approach to semiconductor optical fibers are developed. Specifically, the addition of silicon carbide (SiC) into a silicon (Si) core provides an in-situ reactive getter of oxygen during the draw process to achieve oxygen-free silicon optical fibers. Elemental analysis and x-ray diffraction of fibers drawn using this reactive chemistry approach show negligible oxygen concentration in the highly crystalline silicon core, a significant departure from the nearly 18 atom percent oxygen in previous fibers. Scattering of light out of the core is shown qualitatively to have been reduced in the process. The role of the cross-sectional geometry on the resultant core crystallography with respect to the fiber axis is explored in a continued effort to better understand the nature of the crystal formation and structural properties in these semiconductor core optical fibers. A square cross-sectional geometry was explored to determine if core non-circularity can enhance or promote single crystallinity, as the semiconductors studied have a preference to form cubic crystals. Resultant crystallography of the non-circular core showed a significant improvement in maintaining a preferred crystallographic orientation, with the square core fibers exhibiting a 90% preference for the family of directions occurring closest to the longitudinal direction of the fiber. The ability to orient the crystallography with respect to the fiber axis could be of great value to future nonlinear optical fiber-based devices. In summary, this dissertation begins to elucidate some of the microstructural features, not present in conventional glass optical fibers, which could be important for future low-loss single crystalline semiconductor optical fibers. Additionally, this dissertation offers novel

  9. Sea level variabilities in the Gulf Stream between Cape Hatteras and 50 deg W - A Geosat study

    Science.gov (United States)

    Vazquez, Jorge; Zlotnicki, Victor; Fu, Lee-Lueng

    1990-01-01

    Sea level variabilities in the Gulf Stream between Cape Hatteras and 50 deg W were examined by studying sea level residuals, relative to a 2-yr mean sea level, obtained from Geosat altimetry data for the period between November 1986 and December 1988. An array of sea-level time series was constructed for a region bounded by 30 deg N and 45 deg N in latitude and by 80 deg W and 50 deg W longitude. It is shown that the spectral characteristics of this time series varies with geographic location along the Gulf Stream path. Concurrent NOAA IR images are used to aid in the interpretation of sea level observations in terms of the variability of the stream's path, demonstrating the synergistic value of the combination of satellite-altimeter and IR data.

  10. Creep crack growth in a reactor pressure vessel steel at 360 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Rui Wu; Seitisleam, F.; Sandstroem, R. [Swedish Institute for Metals Research, Stockholm (Sweden)

    1998-12-31

    Plain creep (PC) and creep crack growth (CCG) tests at 360 deg C and post metallography were carried out on a low alloy reactor pressure vessel steel (ASTM A508 class 2) with different microstructures. Lives for the CCG tests were shorter than those for the PC tests and this is more pronounced for simulated heat affected zone microstructure than for the parent metal at longer lives. For the CCG tests, after initiation, the cracks grew constantly and intergranularly before they accelerated to approach rupture. The creep crack growth rate is well described by C*. The relations between reference stress, failure time and steady crack growth rate are presented for the CCG tests. It is demonstrated that the failure stress due to CCG is considerably lower than the yield stress at 360 deg C. Consequently, the CCG will control the static strength of a reactor vessel. (orig.) 17 refs.

  11. The first winter solstice observed at the meridian line of Santa Maria degli Angeli in Rome

    CERN Document Server

    Sigismondi, Costantino

    2014-01-01

    The page written by the astronomer Francesco Bianchini (1662-1729) and containing the data of the 1701 winter solstice observed at Santa Maria degli Angeli is presented for the first time in figure 2 and widely discussed along this paper. The great meridian line in the Basilica of Santa Maria degli Angeli in Rome was built in 1701/1702 with the scope to measure the Obliquity of the Earth's orbit in the following eight centuries, upon the will of pope Clement XI. During the winter solstice of 1701 the first measurements of the obliquity have been realized by Francesco Bianchini, the astronomer who designed the meridian line, upgrading the similar instrument realized by Giandomenico Cassini in San Petronio, Bononia. In this paper the accuracy of the data observed by Francesco Bianchini is discussed and compared with up-to-date ephemerides. The modern situation of this historical instrument is also presented.

  12. Isothermal section at 1400 deg. C of the Ti-Zr-Sn system

    Energy Technology Data Exchange (ETDEWEB)

    Saltykov, V.A. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)], E-mail: ssaltykov@ipms.kiev.ua; Meleshevich, K.A.; Samelyuk, A.V.; Verbytska, O.M.; Bulanova, M.V. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)

    2008-07-14

    By the methods of X-ray diffraction, metallography and microprobe examinations the character of phase equilibria at 1400 deg. C is studied for the Ti-(Ti,Zr){sub 5}Sn{sub 3}-Zr region of the Ti-Zr-Sn system. The isothermal section at 1400 deg. C is constructed. This is similar to the solidus surface and is characterized by two 3-phase regions: <{beta}Ti,Zr> + Ti{sub 3}Sn + (Ti,Zr){sub 5}Sn{sub 3} and Ti{sub 3}Sn + Ti{sub 2}Sn + (Ti,Zr){sub 5}Sn{sub 3}. Solubility of Sn in <{beta}Ti,Zr> solid solution is between 10 and 15 at.% Sn. Solubility of zirconium in Ti{sub 3}Sn is about 12 at.%.

  13. Iron oxidation kinetics study by using infrared spectral emissivity measurements below 570deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Campo, Leire del [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologi' a, Universidad del Pai' s Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Perez-Saez, Raul B. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologi' a, Universidad del Pai' s Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain)], E-mail: raul.perez@ehu.es; Tello, Manuel J. [Departamento de Fisica de la Materia Condensada, Facultad de Ciencia y Tecnologi' a, Universidad del Pai' s Vasco, Barrio Sarriena s/n, 48940 Leioa, Bizkaia (Spain); Instituto de Sintesis y Estudio de Materiales, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao (Spain)

    2008-01-15

    The oxidation kinetics of iron below 570deg. C is investigated through the dependence of the spectral emissivity on the surface oxidation state. Using the theory of radiative effects of thin films, the oxide scale thickness is obtained as a function of time. A parabolic growth has been observed in all the cases, and applying Wagner's theory, the oxidation parabolic rate constants have been calculated at four temperatures. The temperature dependence of these results has additionally been used to obtain the activation energy of the oxidation process in iron. The parabolic rate constants and activation energy values are in good agreement with the theoretical predictions, and this suggests that the lattice diffusion mechanisms for the high temperature magnetite growth also occur until 400deg. C. The experimental results are also useful to test the applicability of emissivity measurements for in situ oxidation kinetics studies in the spectral range where the scales are optically thin.

  14. Millimeter and sub-millimeter heterodyne mixing based on 2DEG hot-electron bolometers

    Science.gov (United States)

    Wang, Kai; Bell, Matthew; Ramaswamy, Rahul; Sergeev, Andrei; Strasser, Gottfried; Mitin, Vladimir

    2010-03-01

    We investigate GHz and THz heterodyne mixer based on the electron heating effect of a two-dimensional electron gas (2DEG) by electromagnetic radiation at liquid nitrogen temperatures (77K). The devices are fabricated from AlGaAs/GaAs heterostructures with a channel width of 150 μm and lengths varying from 3-20 μm. Steady-state measurements are used to investigate electron heating in these devices and determine basic parameters, such as electron-phonon energy relaxation time and electron heat capacity. We perform mixing experiments at ˜100 GHz frequency range with two Gunn diodes as the radiation sources, and find that electron heating is the primary mixing mechanism at these frequencies. For the mixing experiments at ˜ 2 terahertz range, a quantum cascade laser (QCL) is employed as the local oscillator. To optimize our device, we also investigate electron kinetics and transport properties in the 2DEG hot-electron bolometer.

  15. Mechanism of <1 1 2>/3 slip initiation and anisotropy of {gamma}' phase in CMSX-4 during creep at 750 deg. C and 750 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.Z.; Knowles, D.M

    2003-09-15

    Creep deformation defects from tensile creep tests carried out at 750 deg. C under 750 MPa in the approximate orientations [1-bar 3 6], [0 0 1], [0 1 1] and [1 1 1] for CMSX-4 single crystals have been identified carefully, using transmission electron microscope combined with computer simulated microimages. A series of results have been obtained. (i) It was confirmed that <1 1 2>/3 slip in {gamma}' phase mainly involved the reaction and dissociation of two <1 1 0>/2 dislocations which had different Burgers vectors and met at the {gamma}/{gamma}' interfaces where the product <1 1 2>/6 partials were trapped. (ii) At 750 deg. C and 750 MPa, the selectivity among {l_brace}1 1 1{r_brace}<1 1 2> slip systems was sensitive to Schmid factors. The reason for the anisotropy was that the resolved shear stress of highly stressed {l_brace}1 1 1{r_brace}<1 1 2> slip systems in the [1-bar 3 6], [0 0 1] and [0 1 1] orientations were just around the critical resolved shear stress of <1 1 2>/3 faulting in {gamma}' phase which was estimated to be {approx}300 MPa. Hence, a slight decrease of a RSS could switch off the operation of a {l_brace}1 1 1{r_brace}<1 1 2> slip system, or vice versa. (iii) The activation of {l_brace}1 1 1{r_brace}<1 1 0> slip systems was a necessary but not sufficient factor of initiating <1 1 2>/3 faulting in the {gamma}' particles. The operation of <1 1 2>/3 slip and density of superlattice stacking faults were controlled by the RSSs acting on those {l_brace}1 1 1{r_brace}<1 1 2> slip systems.

  16. Entrepreneurial orientation, market orientation, and competitive environment

    DEFF Research Database (Denmark)

    Sørensen, Hans Eibe; Cadogan, John W.

    orientation, and competitive environment shape business performance via a three-way interaction. We test the model using primary data from the CEOs of 270 CEO of manufacturing firms, together with secondary data on these firms' profit performance. An assessment of the results indicates that customer......This study sheds light on the role that the competitive environment plays in determining how elements of market orientation and elements of entrepreneurial orientation interact to influence business success. We develop a model in which we postulate that market orientation, entrepreneurial...... orientations. Also, these moderating effects are stronger for firms operating in highly competitive environments. For the innovativeness component of entrepreneurship, however, the positive relationship between innovativeness and ROA decreases as the competitive environment becomes more hostile....

  17. Object oriented methods

    CERN Document Server

    Graham, Ian

    1994-01-01

    This book is a revision of Ian Graham's successful survey of the whole area of object technology. It covers object- oriented programming, object-oriented design, object- oriented analysis, object-oriented databases and treats several related technologies. New to this edition are more applications of object-oriented methods and more coverage of object-oriented database products available. Graham has also doubled the design and analysis material that examines over 60 different approaches - making this the most comprehensive book on the market. Also new is the foreword by Grady Booch.

  18. PUMA-PUblication MAnagement: sistemi per la gestione delle pubblicazioni degli enti di ricerca

    OpenAIRE

    Biagioni, Stefania

    2005-01-01

    Lo scopo di questa presentazione ? quello di illustrare i) come ? stato realizzato un ciclo gestionale completo dell'informazione: dall'inserimento dei metadati e dei documenti digitali alla restituzione degli stessi all'utente finale; ii) come sono stati resi accessibili via web, a livelli diversi e secondo viste diverse l'informazione prodotta; iii) come siano stati creati servizi differenti utilizzando gli stessi oggetti. Vengono illustrati i sistemi utilizzati presso il CNR di Pisa per la...

  19. Proteomica degli exosomi urinari per la ricerca di biomarcatori nella nefropatia diabetica e nelle tubulopatie ereditarie

    OpenAIRE

    Corbetta,

    2015-01-01

    Le urine costituiscono il fluido biologico di elezione nella ricerca di biomarcatori per le patologie renali in quanto possono essere raccolte in modo semplice e non invasivo; una strategia per la semplificazione del proteoma urinario è rappresentata dall’isolamento degli exosomi urinari (UE), nanovescicole di membrana (30-100 nm) rilasciate dalle cellule epiteliali nello spazio urinario. In questo lavoro abbiamo focalizzato l’attenzione sulla nefropatia diabetica (DN), una comune complicazio...

  20. Observation of Polar Mesosphere Summer Echoes using the Northernmost MST Radar at Eureka (80 deg N)

    Science.gov (United States)

    Swarnalingam, N.; Hocking, W.; Janches, D.; Drummond, J.

    2017-01-01

    We investigate long-term Polar Mesosphere Summer Echoes (PMSEs) observations conducted by the northern most geographically located MST radar at Eureka (80 deg N, 86 deg W). While PMSEs are a well recognized summer phenomenon in the polar regions, previous calibrated studies at Resolute Bay and Eureka using 51.5 MHz and33 MHz radars respectively, showed that PMSE backscatter signal strengths are relatively weak in the polar cap sites, compared to the auroral zone sites (Swarnalingam et al., 2009b; Singer et al., 2010). Complications arise with PMSEs in which the echo strength is controlled by the electrons, which are, in turn, influenced by heavily charged ice particles as well as the variability in the D-region plasma. In recent years, PMSE experiments were conducted inside the polar cap utilizing a 51 MHz radar located at Eureka. In this paper, we investigate calibrated observations, conducted during 2009-2015. Seasonal and diurnal variations of the backscatter signal strengths are discussed and compared to previously published results from the ALOMAR radar, which is a radar of similar design located in the auroral zone at Andenes, Norway (69 deg N, 16 deg E). At Eureka, while PMSEs are present with a daily occurrence rate which is comparable to the rate observed at the auroral zone site for at least two seasons, they show a great level of inter-annual variability. The occurrence rate for the strong echoes tends to be low. Furthermore, comparison of the absolute backscatter signal strengths at these two sites clearly indicates that the PMSE backscatter signal strength at Eureka is weak. Although this difference could be caused by several factors, we investigate the intensity of the neutral air turbulence at Eureka from the measurements of the Doppler spectrum of the PMSE backscatter signals. We found that the level of the turbulence intensity at Eureka is weak relative to previously reported results from three high latitude sites.

  1. Survey of the sky at the 8. 7 and 14. 4 GHz frequencies in the 0 deg - 4 deg declination range

    Energy Technology Data Exchange (ETDEWEB)

    Amirkhanyan, V.R.; Gorshkov, A.G.; Kapustkin, A.A.; Konnikova, V.K.; Lazutkin, A.N.; Larionov, M.G.; Nikanorov, A.S.; Sidorenkov, V.N.; Ugol' kova, L.S.; Khromov, O.I. (Moskovskij Gosudarstvennyj Univ. (USSR). Gosudarstvennyj Astronomicheskij Inst. ' ' GAISh' ' )

    Using the RATAN-600 radiotelescope of the USSR Academy of Sciences (from March 1979 to January 1980) the sky is observed at the 8.7 and 14.4 GHz frequencies in the 0-4 deg declination range. Lists of 82 and 24 radiosources detected at the given frequencies are presented. Six radiosources are detected for the first time. Right ascension and declination, as well as the maximum values of radio-frequency radiation fluxes are given. The problems of measuring accuracies of fluxes and coordinates and the problem of validity of detected radiosources are discussed. On the basis of comparison of the data obtained with those in other works the systematic deviation in fluxes of sources is not more than 7%.

  2. Submillimeter wavelength survey of the galactic plane from l = -5 deg to l = +62 deg - Structure and energetics of the inner disk

    Science.gov (United States)

    Hauser, M. G.; Silverberg, R. F.; Stier, M. T.; Kelsall, T.; Gezari, D. Y.; Dwek, E.; Walser, D.; Mather, J. C.; Cheung, L. H.

    1984-01-01

    Observational results are presented from a new large-scale survey of the first quadrant of the galactic plane at wavelengths of 150, 250, and 300 microns, with a 10 x 10 arcmin beam. The emission detected in the survey arises from compact sources, most of which are identified with known peaks of 5 GHz or CO emission, or both, and from an underlying diffuse background with a typical angular width of about 0.9 deg (FWHM) which accounts for most of the emission. A total of 80 prominent discrete sources are identified and characterized, of which about half have not previously been reported at far-infrared wavelengths. The total infrared luminosity within the solar circle is about 1 to 2 x 10 to the 10th solar luminosity, and is probably emitted by dust that resides in molecular clouds.

  3. Submillimeter wavelength survey of the galactic plane from l = -5 deg to l = +62 deg: Structure and energetics of the inner disk

    Science.gov (United States)

    Hauser, M. G.; Silverberg, R. F.; Stier, M. T.; Kelsall, T.; Gezari, D. Y.; Dwek, E.; Walser, D.; Mather, J. C.; Cheung, L. H.

    1984-01-01

    Results from a large scale survey of the first quadrant of the Milky Way galactic plane at wavelengths of 150, 250, and 300 microns with a 10x10 arcmin beam are presented. The emission detected in the survey arises from compact sources, most of which are identified with known peaks of 5 GHz and/or CO emission, and from an underlying diffuse background with a typical angular width of approximately 0.9 deg (FWHM) which accounts for most of the emission. A total of 80 prominent discrete sources were identified and characterized, of which about half were not previously reported at far infrared wavelengths. The total infrared luminosity within the solar circle is approximately 1 to 2x10 to the 10th power L sub 0, and is probably emitted by dust that resides in molecular clouds.

  4. Photocatalysis application of zinc oxide fibers obtained by electrospinning; Fribras de oxido de zinco obtidas por electrospinning aplicadas a fotocatalise

    Energy Technology Data Exchange (ETDEWEB)

    Gerchman, D.; Alves, A.K.; Berutti, F.A.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (DEM/UFRGS), Porto Alegre, RS (Brazil). Dept. de Materiais

    2010-07-01

    Using the electrospinning technique, composite fibers of polyvinylbutyral and zinc nitrate were obtained. After a heat treatment at 600 deg C, nanostructured zinc oxide fibers were obtained. The fibers were characterized using X ray diffraction. The photocatalytic activity of the nanostructured fibers was determined using the photodegradation of a methyl orange solution. The increase in the heat treatment temperature decreases the photoactivity of the zinc oxide. The heat treatment, the phases and the surface area, affect the physical, chemical and photocatalytic activity of the zinc oxide. (author)

  5. Vortex lift augmentation by suction on a 60 deg swept Gothic wing

    Science.gov (United States)

    Taylor, A. H.; Jackson, L. R.; Huffman, J. K.

    1982-01-01

    An experimental investigation was conducted in the Langley high-speed 7- by 10-foot wind tunnel to determine the aerodynamic performance of suction applied near the wing tips above the trailing edge of a 60 deg swept Gothic wing. Moveable suction inlets were symmetrically mounted in the proximity of the trailing edge, and the amount of suction was varied to maximize wing lift. Tests were conducted at Mach 0.15, 0.30, and 0.45, and the angle of attack was varied from -4 to 50 deg. The suction augmentation increases the lift coefficient over the entire range of angle of attack. The lift improvement exceeds the unaugmented wing lift by over 20%. Moreover, the augmented lift exceeds the lift predicted by vortex lattice theory to 30 deg angle of attack. Suction augmentation is postulated to strengthen the vortex system by increasing its velocity and making it more concentrated. This causes the vortex breakdown to be delayed to a higher angle of attack

  6. submitter Technical Note: Using DEG-CPCs at upper tropospheric temperatures

    CERN Document Server

    Wimmer, D; Nieminen, T; Duplissy, J; Ehrhart, S; Almeida, J; Rondo, L; Franchin, A; Kreissl, F; Bianchi, F; Manninen, H E; Kulmala, M; Curtius, J; Petäjä, T

    2015-01-01

    Over the last few years, several condensation particle counters (CPCs) capable of measuring in the sub-3 nm size range have been developed. Here we study the performance of CPCs based on diethylene glycol (DEG) at different temperatures during Cosmics Leaving OUtdoor Droplets (CLOUD) measurements at CERN. The data shown here are the first set of verification measurements for sub-3 nm CPCs under upper tropospheric temperatures using atmospherically relevant aerosol particles. To put the results in perspective we calibrated the DEG-CPC at room temperature, resulting in a cut-off diameter of 1.4 nm. All diameters refer to mobility equivalent diameters in this paper. At upper tropospheric temperatures ranging from 246.15 K to 207.15 K, we found cut-off sizes relative to a particle size magnifier in the range of 2.5 to 2.8 nm. Due to low number concentration after size classification, the cut-off diameters have a high uncertainty (±0.3 nm) associated with them. Operating two laminar flow DEG-CPCs with different c...

  7. Sexy DEG/ENaC channels involved in gustatory detection of fruit fly pheromones.

    Science.gov (United States)

    Pikielny, Claudio W

    2012-11-06

    Hydrocarbon pheromones on the cuticle of Drosophila melanogaster modulate the complex courtship behavior of males. Recently, three members of the degenerin/epithelial Na+ channel (DEG/ENaC) family of sodium channel subunits, Ppk25, Ppk23, and Ppk29 (also known as Nope), have been shown to function in gustatory perception of courtship-modulating contact pheromones. All three proteins are required for the activation of male courtship by female pheromones. Specific interactions between two of them have been demonstrated in cultured cells, suggesting that, in a subset of cells where they are coexpressed, these three subunits function within a common heterotrimeric DEG/ENaC channel. Such a DEG/ENaC channel may be gated by pheromones, either directly or indirectly, or alternatively may control the excitability of pheromone-sensing cells. In addition, these studies identify taste neurons that respond specifically to courtship-modulating pheromones and mediate their effects on male behavior. Two types of pheromone-sensing taste neurons, F and M cells, have been defined on the basis of their specific response to either female or male pheromones. These reports set the stage for the dissection of the molecular and cellular mechanisms that mediate gustatory detection of contact pheromones.

  8. EDD, a novel phosphotransferase domain common to mannose transporter EIIA, dihydroxyacetone kinase, and DegV.

    Science.gov (United States)

    Kinch, Lisa N; Cheek, Sara; Grishin, Nick V

    2005-02-01

    Using a recently developed program (SCOPmap) designed to automatically assign new protein structures to existing evolutionary-based classification schemes, we identify a evolutionarily conserved domain (EDD) common to three different folds: mannose transporter EIIA domain (EIIA-man), dihydroxyacetone kinase (Dak), and DegV. Several lines of evidence support unification of these three folds into a single superfamily: statistically significant sequence similarity detected by PSI-BLAST; "closed structural grouping" using DALI Z-scores (each protein inside a group finds all other group members with scores higher than those to proteins outside the group) that includes only these proteins sharing a unique alpha-helical hairpin at the C-terminus and excludes all other proteins with similar topology; similar domain fusions connect Dak and DegV, and genomic neighborhood organizations connect Dak and EIIA-man. Finally, both Dak and EIIA-man perform similar phosphotransfer reactions, suggesting a phosphotransferase activity for the DegV-like family of proteins, whose function other than lipid binding revealed in the crystal structure remains unknown.

  9. The Young’s moduli prediction of random distributed short-fiber-reinforced polypropylene foams using finite element method

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The elastic moduli of short-fiber-reinforced foams depend critically on the fiber content and fiber length, as well as on the fiber orientation distribution. Based on periodic tetrakaidecahedrons, the finite element models with short-fiber reinforcement were proposed in this paper to examine the effects of the fiber content and fiber length on Young’s modulus. The fiber length distribution and fiber orientation distribution were also considered. The proposed models featured in a three-dimensional diorama with random short-fiber distribution within or on the surfaces of the walls and edges of the closed-cells of polypropylene (PP) foams. The fiber length/orientation distributions were modeled by Gaussian prob-ability density functions. Different fiber volume fractions, different lengths, and different distributions were investigated. The predicted Young’s moduli of the PP foams with short-glass-fiber or short-carbon-fiber reinforcement were compared with other theoretic and experimental results, and the agreement was found to be satisfactory. The proposed finite element models were proved to be acceptable to predict the Young’s moduli of the grafted closed-cell PP foams with short-fiber reinforcement.

  10. The Young's moduli prediction of random distributed short-fiber-reinforced polypropylene foams using finite element method

    Institute of Scientific and Technical Information of China (English)

    WANG Bo; WANG RongXiu; WU Yong

    2009-01-01

    The elastic moduli of short-fiber-reinforced foams depend critically on the fiber content and fiber length, as well as on the fiber orientation distribution. Based on periodic tetrakaidecahedrons, the finite ele-ment models with short-fiber reinforcement were proposed in this paper to examine the effects of the fiber content and fiber length on Young's modulus. The fiber length distribution and fiber orientation distribution were also considered. The proposed models featured in a three-dimensional diorama with random short-fiber distribution within or on the surfaces of the walls and edges of the closed-cells of polypropylene (PP) foams. The fiber length/orientation distributions were modeled by Gaussian prob-ability density functions. Different fiber volume fractions, different lengths, and different distributions were investigated. The predicted Young's moduli of the PP foams with short-glass-fiber or short-carbon-fiber reinforcement were compared with other theoretic and experimental results, and the agreement was found to be satisfactory. The proposed finite element models were proved to be ac-ceptable to predict the Young's moduli of the grafted closed-cell PP foams with short-fiber reinforce-ment.

  11. Study on the Process Technology of PA6/PET Bicomponent Fiber

    Institute of Scientific and Technical Information of China (English)

    林耀

    2001-01-01

    PA6/PET bicomponent fiber at different spinning speedswere produced. Influences of cross blowing, spinning speed, PA6 and PET component ratio, drawing condition etc. on the mechanical properties, heat shrinkage,orientation and crystallization of the fiber were investigated. Also the rules among these influencing parameters were obtained. The splitting property of the fiber and its influence on the textile processing are discussed, which offers a base for the production of PA6/PET bicomponent fiber using splitting technology.

  12. Mapping misoriented fibers using X-ray dark field tomography

    DEFF Research Database (Denmark)

    Lauridsen, Torsten; Lauridsen, Erik Mejdal; Feidenhans’l, Robert

    2014-01-01

    such tomograms on a highly nonisotropic sample, i.e. a five layer “sandwich” of oriented carbon fibers. The fibers are parallel within the individual sandwich layers, but perpendicular to the fibers in the adjacent layers. We show that by choosing a rotation axis parallel to the grating stepping direction (i.......e. a horizontal rotation axis in most setup configurations) it is possible to produce a darkfield tomogram where fibers parallel to the probed scattering direction appear to have no dark field signal. The method produces a tomogram in the form of a scalar field of dark field scattering values....

  13. Fiber-guided modes conversion using superposed helical gratings

    Science.gov (United States)

    Ma, Yancheng; Fang, Liang; Wu, Guoan

    2017-03-01

    Optical fibers can support various modal forms, including vector modes, linear polarization (LP) modes, and orbital angular momentum (OAM) modes, etc. The modal correlation among these modes is investigated via Jones matrix, associated with polarization and helical phase corresponding to spin angular momentum (SAM) and OAM of light, respectively. We can generate different modal forms by adopting superposed helical gratings (SHGs) with opposite helix orientations. Detailed analysis and discussion on mode conversion is given as for mode coupling in optical fibers with both low and high contrast index, respectively. Our study may deepen the understanding for various fiber-guided modes and mode conversion among them via fiber gratings.

  14. Continuous nanoscale carbon fibers with superior mechanical strength.

    Science.gov (United States)

    Liu, Jie; Yue, Zhongren; Fong, Hao

    2009-03-01

    Continuous nanoscale carbon fibers can be developed by stabilization and carbonization of highly aligned and extensively stretched electrospun polyacrylonitrile copolymer nanofiber precursor under optimal tension. These carbon fibers, with diameters of tens of nanometers, are expected to possess a superior mechanical strength that is unlikely to be achieved through conventional approaches. This is because i) the innovative precursor, with a fiber diameter approximately 100 times smaller than that of conventional counterparts, possesses an extremely high degree of macromolecular orientation and a significantly reduced amount of structural imperfections, and ii) the ultrasmall fiber diameter also effectively prevents the formation of structural inhomogeneity, particularly sheath/core structures during stabilization and carbonization.

  15. Photonic Bandgap Fibers

    DEFF Research Database (Denmark)

    Barkou, Stig Eigil; Broeng, Jes; Bjarklev, Anders Overgaard

    1999-01-01

    Photonic bandgap fibers are describes using a new Kagomé cladding structure. These fibers may potentially guide light in low-index regions. Such fibers offer new dispersion properties, and large design flexibility.......Photonic bandgap fibers are describes using a new Kagomé cladding structure. These fibers may potentially guide light in low-index regions. Such fibers offer new dispersion properties, and large design flexibility....

  16. Migratory blackcaps tested in Emlen funnels can orient at 85 degrees but not at 88 degrees magnetic inclination.

    Science.gov (United States)

    Lefeldt, Nele; Dreyer, David; Schneider, Nils-Lasse; Steenken, Friederike; Mouritsen, Henrik

    2015-01-15

    Migratory birds are known to use the Earth's magnetic field as an orientation cue on their tremendous journeys between their breeding and overwintering grounds. The magnetic compass of migratory birds relies on the magnetic field's inclination, i.e. the angle between the magnetic field lines and the Earth's surface. As a consequence, vertical or horizontal field lines corresponding to 0 or 90 deg inclination should offer no utilizable information on where to find North or South. So far, very little is known about how small the deviations from horizontal or vertical inclination are that migratory birds can detect and use as a reference for their magnetic compass. Here, we asked: what is the steepest inclination angle at which a migratory bird, the Eurasian blackcap (Sylvia atricapilla), can still perform magnetic compass orientation in Emlen funnels? Our results show that blackcaps are able to orient in an Earth's strength magnetic field with inclination angles of 67 and 85 deg, but fail to orient in a field with 88 deg inclination. This suggests that the steepest inclination angle enabling magnetic compass orientation in migratory blackcaps tested in Emlen funnels lies between 85 and 88 deg.

  17. They Call it Orienteering

    Science.gov (United States)

    Wexler, Mark

    1977-01-01

    Through the use of personal anecdotes, the author details his initial experience with orienteering, a sport rapidly increasing in popularity that teaches people not to get lost in the woods. Sources of information about orienteering are provided. (BT)

  18. Theories of Sexual Orientation.

    Science.gov (United States)

    Storms, Michael D.

    1980-01-01

    Results indicated homosexuals, heterosexuals, and bisexuals did not differ within each sex on measures of masculinity and femininity. Strong support was obtained for the hypothesis that sexual orientation relates primarily to erotic fantasy orientation. (Author/DB)

  19. La valorizzazione degli spazi residuali del tessuto edilizio consolidato: una ricognizione dei più recenti progetti in Europa

    Directory of Open Access Journals (Sweden)

    Carlotta Cecchini

    2014-06-01

    Full Text Available Intervenire sui tessuti marginali significa interfacciarsi con realtà complesse, nelle quali l’ identità locale, seppur non evidente o indebolita dallo stato di degrado, si è mantenuta, o addirittura rafforzata, nel tempo, andando a rappresentare una ricchezza in grado di dialogare con le risorse interne ed al contorno dell’area residuale stessa. Il presente contributo ha lo scopo di individuare e definire le strategie di valorizzazione  maggiormente efficaci nella gestione dei tessuti periferici, attraverso un’indagine dei migliori progetti di riqualificazione in ambito europeo e l’analisi delle strategie d’indirizzo da essi applicate. Vengono a questo proposito individuati due gradi di intervento: uno a livello generale, nel quale l’approccio con il tessuto antropico/naturalistico esistente fornisce un primo orientamento strategico nella gestione del “progetto complesso”, realizzandosi nella definizione degli ambiti di valorizzazione del tessuto di riferimento; uno a scala ravvicinata, nel quale vengono definite le modalità di gestione della materia (sia naturale che artificiale, che si concretizza nelle scelte di carattere operativo.   Intervening in marginal areas means to interface with complex realities, in which the local identity survived (or even increased, even if hidden or weakened by decline condition. They become an asset able to dialogue with its own internal and environmental resources. The present study is aimed at identifying and defining the most effective strategies in periphery management, through an investigation on European best practices and the definition of common designing criteria. At this purpose, two levels of intervention are defined: a general approach, in which the relationship between anthropic/natural existing tissue analysis gives a first orienting about the strategies to be applied in the complex project. This phase is aimed at defining the values of the reference areas; a close

  20. Orientation and Spatial Frequency Selectivity following Adaptation: A Reaction Time Study.

    Science.gov (United States)

    Plainis, Sotiris; Parry, Neil R A; Sapountzis, Panagiotis; Murray, Ian J

    2015-03-01

    The aim of the study was to determine orientation and spatial frequency sensitivity using reaction times (RTs) in an adaptation paradigm. Simple RTs were measured to the onset of a Gabor patch (SD = 1.2 deg, spatial frequency = 4 cycles deg(-1)). Observers adapted for 10 s to a 4 cycles deg(-1) grating presented at a series of orientations (0, 2, 5, 10, 22.5, 45, 90°) or spatial frequencies (±0.5, 1, and 2 octaves). The contrast of the test grating was 4x each participant's unadapted threshold. The effect of adaptation was evaluated by transforming RTs to effective contrast reduction using RT-based contrast response functions. RTs increased by between ∼ 100 ms to 150 ms when the test and adapting gratings were of the same orientation or spatial frequency. The effect became less pronounced as the difference in orientation or spatial frequency increased. The average bandwidths for orientation and spatial frequency were 17.4° and 1.24 octaves, respectively. The method has some advantages over traditional approaches. It reveals a rapid time course of adaptation recovery with a half-life of about 13 s to 23 s. RTs form a rapid and easily implemented technique for assessing the underlying physiological mechanisms that control adaptation at suprathreshold levels of contrast.

  1. Experimental development of advanced air filtration media based on electrospun polymer fibers

    Science.gov (United States)

    Ghochaghi, Negar

    Electrospinning is a process by which polymer fibers can be produced using an electrostatically driven fluid jet. Electrospun fibers can be produced at the micro- or nano-scale and are, therefore, very promising for air filtration applications. However, because electrospun fibers are electrically charged, it is difficult to control the morphology of filtration media. Fiber size, alignment and uniformity are very important factors that affect filter performance. The focus of this project is to understand the relationship between filter morphology and performance and to develop new methods to create filtration media with optimum morphology. This study is divided into three focus areas: unimodal and bimodal microscale fibrous media with aligned, orthogonal and random fiber orientations; unimodal and bimodal nanoscale fibers in random orientations; bimodal micrometer and nanometer fiber media with orthogonally aligned orientations. The results indicate that the most efficient filters, which are those with the highest ratio of particle collection efficiency divided by pressure drop, can be obtained through fabricating filters in orthogonal layers of aligned fibers with two different fiber diameters. Moreover, our results show that increasing the number of layers increases the performance of orthogonally layered fibers. Also, controlling fiber spacing in orthogonally layered micrometer fiber media can be an alternative way to study the filtration performance. Finally, such coatings presented throughout this research study can be designed and placed up-stream, down-stream, and/or in between conventional filters.

  2. Entrepreneurial orientation, market orientation, and competitive environment

    DEFF Research Database (Denmark)

    Sørensen, Hans Eibe; Cadogan, John W.

    orientation, and competitive environment shape business performance via a three-way interaction. We test the model using primary data from the CEOs of 270 CEO of manufacturing firms, together with secondary data on these firms' profit performance. An assessment of the results indicates that customer...... orientation moderates the positive relationships between the competitiveness element of entrepreneurial orientation and market share and return on assets (ROA): the positive relationships between competitiveness and market share and competitiveness and ROA become stronger the greater the firms' customer...

  3. Leading non-Gaussian corrections for diffusion orientation distribution function.

    Science.gov (United States)

    Jensen, Jens H; Helpern, Joseph A; Tabesh, Ali

    2014-02-01

    An analytical representation of the leading non-Gaussian corrections for a class of diffusion orientation distribution functions (dODFs) is presented. This formula is constructed from the diffusion and diffusional kurtosis tensors, both of which may be estimated with diffusional kurtosis imaging (DKI). By incorporating model-independent non-Gaussian diffusion effects, it improves on the Gaussian approximation used in diffusion tensor imaging (DTI). This analytical representation therefore provides a natural foundation for DKI-based white matter fiber tractography, which has potential advantages over conventional DTI-based fiber tractography in generating more accurate predictions for the orientations of fiber bundles and in being able to directly resolve intra-voxel fiber crossings. The formula is illustrated with numerical simulations for a two-compartment model of fiber crossings and for human brain data. These results indicate that the inclusion of the leading non-Gaussian corrections can significantly affect fiber tractography in white matter regions, such as the centrum semiovale, where fiber crossings are common.

  4. Fiber Assignment in Next-generation Wide-field Spectrographs

    CERN Document Server

    Morales, Isaac; Azzaro, Marco; Prada, Francisco; Sanchez, Justo; Becerril, Santiago

    2011-01-01

    We present an optimized algorithm for assigning fibers to targets in next-generation fiber-fed multi-object spectrographs. The method, that we named draining algorithm, ensures that the maximum number of targets in a given target field is observed in the first few tiles. Using randomly distributed targets and mock galaxy catalogs we have estimated that the gain provided by the draining algorithm as compared to a random assignment can be as much as 2% for the first tiles. This would imply for a survey like BigBOSS saving for observation several hundred thousand objects or, alternatively, reducing the covered area in ~350 sq. deg. An important advantage of this method is that the fiber collision problem can be solved easily and in an optimal way. We also discuss additional optimizations of the fiber positioning process. In particular, we show that allowing for rotation of the focal plane can improve the efficiency of the process in ~3.5-4.5% even if only small adjustments are permitted (up to 2 deg). For instru...

  5. Processes and applications of silicon carbide nanocomposite fibers

    Energy Technology Data Exchange (ETDEWEB)

    Shin, D G; Cho, K Y; Riu, D H [Nanomaterials Team, Korea Institute of Ceramic Engineering and Technology, 233-5 Gasan-dong, Guemcheon-gu, Seoul 153-801 (Korea, Republic of); Jin, E J, E-mail: dhriu15@seoultech.ac.kr [Battelle-Korea Laborotary, Korea University, Anamdong, Seongbuk-gu, Seoul (Korea, Republic of)

    2011-10-29

    Various types of SiC such as nanowires, thin films, foam, and continuous fibers have been developed since the early 1980s, and their applications have been expanded into several new applications, such as for gas-fueled radiation heater, diesel particulate filter (DPF), ceramic fiber separators and catalyst/catalyst supports include for the military, aerospace, automobile and electronics industries. For these new applications, high specific surface area is demanded and it has been tried by reducing the diameter of SiC fiber. Furthermore, functional nanocomposites show potentials in various harsh environmental applications. In this study, silicon carbide fiber was prepared through electrospinning of the polycarbosilane (PCS) with optimum molecular weight distribution which was synthesized by new method adopting solid acid catalyst such as ZSM-5 and {gamma}-Al{sub 2}O{sub 3}. Functional elements such as aluminum, titanium, tungsten and palladium easily doped in the precursor fiber and remained in the SiC fiber after pyrolysis. The uniform SiC fibers were produced at the condition of spinning voltage over 20 kV from the PCS solution as the concentration of 1.3 g/ml in DMF/Toluene (3:7) and pyrolysis at 1200deg. C. Pyrolyzed products were processed into several interesting applications such as thermal batteries, hydrogen sensors and gas filters.

  6. Fiber Reinforcement in Injection Molded Nylon 6/6 Spur Gears

    Science.gov (United States)

    Senthilvelan, S.; Gnanamoorthy, R.

    2006-07-01

    Injection molded polymer composite gears are being used in many power and or motion transmission applications. In order to widen the utilization of reinforced polymers for precision motion transmission and noise less applications, the accuracy of molded gears should be increased. Since the injection molded gear accuracy is significantly influenced by the material shrinkage behaviour, there is a need to understand the influence of fiber orientation and gate location on part shrinkage behaviour and hence the gear accuracy. Unreinforced and 20% short glass fiber reinforced Nylon 6/6 spur gears were injection molded in the laboratory and computer aided simulations of gear manufacturing was also carried out. Results of the mold flow simulation of gear manufacturing were correlated with the actual fiber orientation and measured major geometrical parameters of the molded gears. Actual orientation of the fibers near the tooth profile, weld line region and injection points of molded gears were observed using optical microscope and correlated with predicted fiber orientation.

  7. Tensorial Orientation Scores

    NARCIS (Netherlands)

    van de Gronde, Jasper J.; Azzopardi, George; Petkov, Nicolai

    2015-01-01

    Orientation scores are representations of images built using filters that only select on orientation (and not on the magnitude of the frequency). Importantly, they allow (easy) reconstruction, making them ideal for use in a filtering pipeline. Traditionally a specific set of orientations has to be c

  8. All-digital signal-processing open-loop fiber-optic gyroscope with enlarged dynamic range.

    Science.gov (United States)

    Wang, Qin; Yang, Chuanchuan; Wang, Xinyue; Wang, Ziyu

    2013-12-15

    We propose and realize a new open-loop fiber-optic gyroscope (FOG) with an all-digital signal-processing (DSP) system where an all-digital phase-locked loop is employed for digital demodulation to eliminate the variation of the source intensity and suppress the bias drift. A Sagnac phase-shift tracking method is proposed to enlarge the dynamic range, and, with its aid, a new open-loop FOG, which can achieve a large dynamic range and high sensitivity at the same time, is realized. The experimental results show that compared with the conventional open-loop FOG with the same fiber coil and optical devices, the proposed FOG reduces the bias instability from 0.259 to 0.018 deg/h, and the angle random walk from 0.031 to 0.006 deg/h(1/2), moreover, enlarges the dynamic range to ±360 deg/s, exceeding the maximum dynamic range ±63 deg/s of the conventional open-loop FOG.

  9. Modal dynamics in multimode fibers

    CERN Document Server

    Fridman, Moti; Nixon, Micha; Friesem, Asher A; Davidson, Nir

    2010-01-01

    The dynamics of modes and their states of polarizations in multimode fibers as a function of time, space, and wavelength are experimentally and theoretically investigated. The results reveal that the states of polarizations are displaced in Poincare sphere representation when varying the angular orientations of the polarization at the incident light. Such displacements, which complicates the interpretation of the results, are overcome by resorting to modified Poincare spheres representation. With such modification it should be possible to predict the output modes and their state of polarization when the input mode and state of polarization are known.

  10. Inactivation of the Deg protease family in the cyanobacterium Synechocystis sp. PCC 6803 has impact on the outer cell layers.

    Science.gov (United States)

    Cheregi, Otilia; Miranda, Hélder; Gröbner, Gerhard; Funk, Christiane

    2015-11-01

    The serine type Deg/HtrA proteases are distributed in a wide range of organisms from Escherichia coli to humans. The cyanobacterium Synechocystis sp. PCC 6803 possesses three Deg protease orthologues: HtrA, HhoA and HhoB. Previously we compared Synechocystis 6803 wild type cells exposed to mild or severe stress conditions with a mutant lacking all three Deg proteases and demonstrated that stress had strong impact on the proteomes and metabolomes. To identify the biochemical processes, which this protease family is involved in, here we compared Synechocystis sp. PCC 6803 wild type cells with a mutant lacking all three Deg proteases grown under normal growth conditions (30°C and 40 μmol photons m(-2) s(-1)). Deletion of the Deg proteases lead to the down-regulation of proteins related to the biosynthesis of outer cell layers (e.g. the GDP mannose 4,6-dehydratase) and affected protein secretion. During the late growth phase of the culture Deg proteases were found to be secreted to the extracellular medium of the Synechocystis sp. PCC 6803 wild type strain. While cyanobacterial Deg proteases seem to act mainly in the periplasmic space, deletion of the three proteases influences the proteome and metabolome of the whole cell. Impairments in the outer cell layers of the triple mutant might explain the higher sensitivity toward light and oxidative stress, which was observed earlier by Barker and coworkers. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Rate dependent response and failure of a ductile epoxy and carbon fiber reinforced epoxy composite

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Eric N [Los Alamos National Laboratory; Rae, Philip J [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Stahl, David B [Los Alamos National Laboratory

    2010-01-01

    An extensive characterization suite has been performed on the response and failure of a ductile epoxy 55A and uniaxial carbon fiber reinforced epoxy composite of IM7 fibers in 55A resin from the quasistatic to shock regime. The quasistatic and intermediate strain rate response, including elastic modulus, yield and failure have are characterized by quasistatic, SHPB, and DMA measurements as a function of fiber orientation and temperature. The high strain rate shock effect of fiber orientation in the composite and response of the pure resin are presented for plate impact experiments. It has previously been shown that at lower impact velocities the shock velocity is strongly dependent on fiber orientation but at higher impact velocity the in-plane and through thickness Hugoniots converge. The current results are compared with previous studies of the shock response of carbon fiber composites with more conventional brittle epoxy matrices. The spall response of the composite is measured and compared with quasistatic fracture toughness measurements.

  12. Proper orientation of cacti

    OpenAIRE

    Araujo, Julio; Havet, Frédéric; Linhares Sales, Claudia; Silva, Ana

    2016-01-01

    International audience; An orientation of a graph G is proper if two adjacent vertices have different in-degrees. The proper-orientation number − → χ (G) of a graph G is the minimum maximum in-degree of a proper orientation of G. In [1], the authors ask whether the proper orientation number of a planar graph is bounded. We prove that every cactus admits a proper orientation with maximum in-degree at most 7. We also prove that the bound 7 is tight by showing a cactus having no proper orientati...

  13. Wood versus Plant Fibers: Similarities and Differences in Composite Applications

    Directory of Open Access Journals (Sweden)

    Bo Madsen

    2013-01-01

    Full Text Available The work on cellulose fiber composites is typically strictly divided into two separated research fields depending on the fiber origin, that is, from wood and from annual plants, representing the two different industries of forest and agriculture, respectively. The present paper evaluates in parallel wood fibers and plant fibers to highlight their similarities and differences regarding their use as reinforcement in composites and to enable mutual transfer of knowledge and technology between the two research fields. The paper gives an introduction to the morphology, chemistry, and ultrastructure of the fibers, the modeling of the mechanical properties of the fibers, the fiber preforms available for manufacturing of composites, the typical mechanical properties of the composites, the modeling of the mechanical properties with focus on composites having a random fiber orientation and a non-negligible porosity content, and finally, the moisture sensitivity of the composites. The performance of wood and plant fiber composites is compared to the synthetic glass and carbon fibers conventionally used for composites, and advantages and disadvantages of the different fibers are discussed.

  14. Orientalism and India

    Directory of Open Access Journals (Sweden)

    Jukka Jouhki

    2006-01-01

    Full Text Available In this article Orientalism, a special hegemonic discourse about "the Orient" by Europeans is discussed by focusing on how it is manifested in a "Western" view of India. Orientalism as a discourse about the Orient is a concept first coined by Edward Said in his book Orientalism (1978 and contains a long history of European way of relating to the Orient as a counterpart of European/Western culture. In this article Orientalist discourses about India by hegemonically Western (and particularly Anglo-Saxon sources are portrayed and the so-called Indo-Orientalist essentialism defining Indianness from the outside analyzed. Moreover, a Indo-Orientalism as an imported ideology to be used in Indian nationalist discourses to emphasize a dichotomy between India and "the West" is discussed.

  15. Wind-tunnel investigation of the flow correction for a model-mounted angle of attack sensor at angles of attack from -10 deg to 110 deg. [Langley 12-foot low speed wind tunnel test

    Science.gov (United States)

    Moul, T. M.

    1979-01-01

    A preliminary wind tunnel investigation was undertaken to determine the flow correction for a vane angle of attack sensor over an angle of attack range from -10 deg to 110 deg. The sensor was mounted ahead of the wing on a 1/5 scale model of a general aviation airplane. It was shown that the flow correction was substantial, reaching about 15 deg at an angle of attack of 90 deg. The flow correction was found to increase as the sensor was moved closer to the wing or closer to the fuselage. The experimentally determined slope of the flow correction versus the measured angle of attack below the stall angle of attack agreed closely with the slope of flight data from a similar full scale airplane.

  16. Quando il teatro si mise in cammino. Il viaggio di Peter Brook e del Centre International de Recherches Théâtrales negli anni Settanta, in compagnia del poema persiano Il verbo degli uccelli

    Directory of Open Access Journals (Sweden)

    Roberta Gandolfi

    2013-01-01

    Full Text Available La dimensione del viaggio in zone altre del mondo acquistò particolare intensità per le compagnie teatrali occidentali degli anni Sessanta e Settanta: qui si ricostruisce in dettaglio uno di questi percorsi, il nomadismo dell'ensemble di Peter Brook in Africa, in Medio Oriente e nelle Americhe, discutendone le valenze in termini di ricerca teatrale e drammaturgica. Si interroga in particolare l'uso della epopea sufi di Farid od-Din 'Attar come testo-incontro, atto a favorire la costruzione di comuni immaginari simbolici con vari pubblici e a sviluppare originali forme di training attorico.

  17. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D;

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  18. Photonic crystal fibers -

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou

    2002-01-01

    During this ph.d. work, attention has been focused on understanding and analyzing the modal behavior of micro-structured fibers. Micro-structured fibers are fibers with a complex dielectric toplogy, and offer a number of novel possibilities, compared to standard silica based optical fibers. The t...

  19. Photonic Crystal Fiber Attenuator

    Institute of Scientific and Technical Information of China (English)

    Joo; Beom; Eom; Hokyung; Kim; Jinchae; Kim; Un-Chul; Paek; Byeong; Ha; Lee

    2003-01-01

    We propose a novel fiber attenuator based on photonic crystal fibers. The difference in the modal field diameters of a conventional single mode fiber and a photonic crystal fiber was used. A variable optical attenuator was also achieved by applying macro-bending on the PCF part of the proposed attenuator

  20. Computational modeling of ring textures in mesophase carbon fibers

    Directory of Open Access Journals (Sweden)

    de Andrade Lima Luiz Rogério Pinho

    2003-01-01

    Full Text Available Carbon fibers are widely used in many industrial applications due the fact of their excellent properties. Carbonaceous mesophases are liquid crystalline precursor materials that can be spun into high performance carbon fibers using the melt spinning process, which is a flow cascade consisting of pressure driven flow-converging die flow-free surface extensional spinline flow that modifies the precursor molecular orientation structure. Carbon fiber property optimization requires a better understanding of the principles that control the structure development during the fiber formation processes and the rheological processing properties. This paper presents the elastic and continuum theory of liquid crystalsand computer simulations of structure formation for pressure-driven flow of carbonaceous liquid crystalline precursors used in the industrial carbon fiber spinning process. The simulations results capture the formation of characteristic fiber macro-textures and provide new knowledge on the role of viscous and elastic effects in the spinning process.

  1. Analysis of Microstructure of Silicon Carbide Fiber by Raman Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Baohong JIN; Nanlin SHI

    2008-01-01

    The SiC fiber was prepared by chemical vapour depostion, which consists of tungsten core, SiC layer and carbon coating. The microstructure of the fiber was investigated using Raman spectroscopy, illustrating SiC variation in different region of the fiber. The result shows that the SiC layer can be subdivided into two parts in the morphologies of SiC grains; their sizes increase and their orientations become order with increasing distance from the fiber center. It is demonstrated that the mount of free carbon in the fiber is responsible for the variation of SiC grains in sizes and morphologies. The analysis of Raman spectra shows that the predominant β-SiC has extensive stacking faults within the crystallites and mixes other polytypes and amorphous SiC into the structure in the fiber.

  2. Model of a thin film optical fiber fluorosensor

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1991-03-01

    The efficiency of core-light injection from sources in the cladding of an optical fiber is modeled analytically by means of the exact field solution of a step-profile fiber. The analysis is based on the techniques by Marcuse (1988) in which the sources are treated as infinitesimal electric currents with random phase and orientation that excite radiation fields and bound modes. Expressions are developed based on an infinite cladding approximation which yield the power efficiency for a fiber coated with fluorescent sources in the core/cladding interface. Marcuse's results are confirmed for the case of a weakly guiding cylindrical fiber with fluorescent sources uniformly distributed in the cladding, and the power efficiency is shown to be practically constant for variable wavelengths and core radii. The most efficient fibers have the thin film located at the core/cladding boundary, and fibers with larger differences in the indices of refraction are shown to be the most efficient.

  3. Carbon fiber composite characterization in adverse thermal environments.

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Vasquez, Sylvia; Brown, Alexander L.; Hubbard, Joshua A.; Ramirez, Ciro J.; Dodd, Amanda B.

    2011-05-01

    The behavior of carbon fiber aircraft composites was studied in adverse thermal environments. The effects of resin composition and fiber orientation were measured in two test configurations: 102 by 127 millimeter (mm) test coupons were irradiated at approximately 22.5 kW/m{sup 2} to measure thermal response, and 102 by 254 mm test coupons were irradiated at approximately 30.7 kW/m{sup 2} to characterize piloted flame spread in the vertically upward direction. Carbon-fiber composite materials with epoxy and bismaleimide resins, and uni-directional and woven fiber orientations, were tested. Bismaleimide samples produced less smoke, and were more resistant to flame spread, as expected for high temperature thermoset resins with characteristically lower heat release rates. All materials lost approximately 20-25% of their mass regardless of resin type, fiber orientation, or test configuration. Woven fiber composites displayed localized smoke jetting whereas uni-directional composites developed cracks parallel to the fibers from which smoke and flames emanated. Swelling and delamination were observed with volumetric expansion on the order of 100% to 200%. The purpose of this work was to provide validation data for SNL's foundational thermal and combustion modeling capabilities.

  4. Lampi di possibili tempeste. Arte e letteratura nel Foucault degli anni Settanta.

    Directory of Open Access Journals (Sweden)

    Diego Melegari

    2012-12-01

    Full Text Available Dopo avere rivestito un ruolo fondamentale negli scritti archeologici degli anni Sessanta, i riferimenti a pittura e letteratura sembrano scomparire dalla riflessione foucaultiana. Si tratta, in realtà, di uno slittamento dalle opere maggiori a brevi interventi in cui ad emergere è soprattutto il coinvolgimento soggettivo di Foucault. Questo passaggio, però, non è che un aspetto di una radicale riformulazione della funzione storico-ontologica precedentemente attribuita a letteratura e arte in favore di forme di esperienza non-strategica, dunque irriducibile al nesso potere-resistenza, e allo stesso tempo riattivabile come critica, anche politica, nel rapporto tra tempo storico e trasformazione della soggettività.

  5. Il problema dei futuri contingenti e la semantica relativista degli enunciati al futuro

    Directory of Open Access Journals (Sweden)

    Diana Mazzarella

    2011-11-01

    Full Text Available L'articolo si propone tre obiettivi. In primo luogo, introdurre al problema dei futuri contingenti, evidenziando i limiti di un'analisi semantica standard degli enunciati al futuro. In secondo luogo, presentare le strategie di implementazione della semantica standard finalizzate ad un approccio semantico di tipo relativistico, distinguendo tra relativismo moderato e relativismo radicale. In terzo luogo, presentare il tentativo di risoluzione del problema in questione attraverso l'adozione di una prospettiva semantica relativista, con esplicito riferimento alle riflessioni di MacFarlane.

  6. L’avventura del teatro granducale degli Uffizi (1586-1637

    Directory of Open Access Journals (Sweden)

    Anna Maria Testaverde

    2016-06-01

    Full Text Available The essay reconstructs the chronological details of the construction and disposal of the Teatro degli Uffizi. An extensive unpublished documentation, and a newly discovered plan of the theatre in the Archivio di Stato di Modena, bring to light hitherto unknown persons and situations. The study anticipates reflections and proposals for a structural solution that would modify the model proposed in 1975 by Ludovico Zorzi. As a foundation of these new hypotheses, the essay offers a re-reading of the Vitruvius’s theories on which the florentine highly specialised technical skills were based on.

  7. “Il coraggio di essere giovani”: un progetto sulla Fgci di Modena degli anni Ottanta

    Directory of Open Access Journals (Sweden)

    Claudia Capelli

    2015-12-01

    Full Text Available L’Istituto Storico di Modena promuove una ricerca sulla Fgci di Modena degli anni Ottanta con l'obiettivo di cominciare a riflettere sul decennio conclusivo della storia del Pci, un periodo di crisi profonda della cultura politica comunista che la storiografia non ha ancora affrontato in modo sistematico. Il caso modenese permette di osservare alcuni importanti elementi dell'esperienza della Fgci “rifondata”, come il nuovo approccio alla comunicazione politica e il rapporto con i movimenti sociali.

  8. Fattori di crescita e recettori tirosin chinasici nelle neoplasie e displasie degli animali domestici

    OpenAIRE

    Muscatello, Luisa Vera

    2016-01-01

    La perdita della comunicazione cellulare può portare ad una crescita deregolata e dunque alla trasformazione neoplastica. Gli scopi dello studio di dottorato sono stati di individuare il rapporto funzionale di alcuni fattori di crescita (FC) e dei loro recettori (RTC) in tipi di neoplasie e displasie degli animali domestici, quali: 1. Amplificazione del proto-oncogene ERBB2 e sovra-espressione del RTC erb-b2. in tumori mammari della gatta. 2. Espressione di erb-b2, di recettori ormonal...

  9. A DECODER NMR study of backbone orientation in Nephila clavipes dragline silk under varying strain and draw rate.

    Science.gov (United States)

    Eles, Philip T; Michal, Carl A

    2004-01-01

    Using DECODER (direction exchange with correlation for orientation distribution evaluation and reconstruction) NMR, we probe the orientations of carbonyl carbons in [1-(13)C]glycine-labeled dragline silk under conditions of varying strain and fiber draw rate. A model-specific reconstruction of the molecular orientation distribution incorporating beta sheets and polyglycine II helices indicates that the structures' alignment along the fiber can be described by a pair of Gaussian distributions with full width at half-maxima of 20 and 68 degrees and approximately 45 and approximately 55% relative contributions to the signal intensity. The alignment along the fiber was found to change appreciably when the drawing tension on the fiber was relaxed in a sample drawn at 4 cm/s while little change was observed in a sample drawn at 2 cm/s. The degree of alignment along the fiber was found to increase with fiber draw rate.

  10. A catalogue of galaxies behind the southern Milky Way. - II. The Crux and Great Attractor regions (l = 289deg - 338deg)

    CERN Document Server

    Woudt, P A; Woudt, Patrick A.; Kraan-Korteweg, Renee C.

    2001-01-01

    In this second paper of the catalogue series of galaxies behind the southern Milky Way, we report on the deep optical galaxy search in the Crux region (289deg = 0.2 arcmin were identified in this ~850 square degree area: 3759 galaxies in the Crux region and 4423 galaxies in the Great Attractor region. Of the 8182 galaxies, 229 (2.8%) were catalogued before in the optical (3 in radio) and 251 galaxies have a reliable (159), or likely (92) cross-identification in the IRAS Point Source Catalogue (3.1%). A number of prominent overdensities and filaments of galaxies are identified. They are not correlated with the Galactic foreground extinction and hence indicative of extragalactic large-scale structures. Redshifts obtained at the South African Astronomical Observatory (SAAO) for 518 of the newly catalogued galaxies in the Crux and Great Attractor regions (Fairall et al. 1998; Woudt et al. 1999) confirm distinct voids and clusters in the area here surveyed. With this optical galaxy search, we have reduced the widt...

  11. Oriented nanofibers embedded in a polymer matrix

    Science.gov (United States)

    Barrera, Enrique V. (Inventor); Rodriguez-Macias, Fernando J. (Inventor); Lozano, Karen (Inventor); Chibante, Luis Paulo Felipe (Inventor); Stewart, David Harris (Inventor)

    2011-01-01

    A method of forming a composite of embedded nanofibers in a polymer matrix is disclosed. The method includes incorporating nanofibers in a plastic matrix forming agglomerates, and uniformly distributing the nanofibers by exposing the agglomerates to hydrodynamic stresses. The hydrodynamic said stresses force the agglomerates to break apart. In combination or additionally elongational flow is used to achieve small diameters and alignment. A nanofiber reinforced polymer composite system is disclosed. The system includes a plurality of nanofibers that are embedded in polymer matrices in micron size fibers. A method for producing nanotube continuous fibers is disclosed. Nanofibers are fibrils with diameters of 100 nm, multiwall nanotubes, single wall nanotubes and their various functionalized and derivatized forms. The method includes mixing a nanofiber in a polymer; and inducing an orientation of the nanofibers that enables the nanofibers to be used to enhance mechanical, thermal and electrical properties. Orientation is induced by high shear mixing and elongational flow, singly or in combination. The polymer may be removed from said nanofibers, leaving micron size fibers of aligned nanofibers.

  12. High power fiber lasers

    Institute of Scientific and Technical Information of China (English)

    LOU Qi-hong; ZHOU Jun

    2007-01-01

    In this review article, the development of the double cladding optical fiber for high power fiber lasers is reviewed. The main technology for high power fiber lasers, including laser diode beam shaping, fiber laser pumping techniques, and amplification systems, are discussed in de-tail. 1050 W CW output and 133 W pulsed output are ob-tained in Shanghai Institute of Optics and Fine Mechanics, China. Finally, the applications of fiber lasers in industry are also reviewed.

  13. MODIS/Terra 8-Day Clear Sky Radiance Bias Daily L3 Global 1Deg Zonal Bands V006

    Data.gov (United States)

    National Aeronautics and Space Administration — MODIS 8-day clear-sky radiance bias (observed - calculated) statistics are provided for 1Deg latitudinal zones and selected thermal bands. Separation by day and...

  14. MODIS/Aqua 8-Day Clear Sky Radiance Bias Daily L3 Global 1Deg Zonal Bands V006

    Data.gov (United States)

    National Aeronautics and Space Administration — MODIS 8-day clear-sky radiance bias (observed - calculated) statistics are provided for 1Deg latitudinal zones and selected thermal bands. Separation by day and...

  15. Orientation Relationship Between Magnetic Domains and Twins in Ni52Fe17Ga27Co4 Magnetic Shape Memory Alloy

    Science.gov (United States)

    Hu, Qiaodan; Yang, Liang; Zhou, Zhenni; Huang, Yujin; Li, Jun; Li, Jianguo

    2017-06-01

    The orientation relationship between magnetic domain and twins in the directional solidified Ni52Fe17Ga27Co4 magnetic shape memory alloy was analyzed by electron backscatter diffraction and magnetic force microscopy. The twin interface plane was determined to be { \\bar{1}10} plates. The magnetic domains walls with a misorientation about 5 deg belong to low angle boundaries. According to the orientation relationship between twins and magnetic domains, the intersection angle on the observed surface can be estimated.

  16. Virtual Orienteering Game For Smartphones

    OpenAIRE

    Sainio, Kari

    2015-01-01

    Orienteering is a relatively famous sports activity in Nordic countries. Today technology provides attractive means for transition from traditional orienteering to virtual orienteering. Virtual orienteering can be thought as orienteering without using a traditional printed map and compass. On the other hand smartphones contain technology for implementing virtual orienteering. There are different smartphone platforms and types, making application development challenging because several cod...

  17. Two-dimensional electron gas at surfaces of (001), (110), and (111) oriented SrTiO3 induced by Ar+-irradiation

    Science.gov (United States)

    Miao, Ludi; Du, Renzhong; Yin, Yuewei; Li, Qi

    2015-03-01

    Two-dimensional electron gases (2DEGs) at transition metal oxide surfaces and interfaces have attracted much attention due to their fascinating exotic properties such as superconductivity, large magneto-resistance (MR), and ferromagnetism. We have created 2DEGs at the surfaces of (001), (110), and (111) oriented SrTiO3 (STO) by Ar+-irradiation and measured their transport properties. The 2DEGs exhibit a fully metallic behavior with the 2D charge carrier density around 2 ×1014 cm-2 and the mobility as large as 5500 cm2V-1s-1 at low temperatures, which is tunable by electric fields applied through STO back gates. We have measured MR anisotropy of the 2DEGs at surfaces of STO with all orientations. We observed combinations of two types of components in their anisotropic MR at low temperatures. While the first type is an STO-orientation-independent two-fold component results from the Lorentz force effect, the second type shows stark differences between these 2DEGs as a consequence of distinct Fermi surface symmetries with different STO orientations. Indeed, it is four-fold for STO (001), two-fold for STO (110) and six-fold for STO (111), respectively.

  18. Time-dependent Creep Crack Growth Behavior of Alloy 617 at 800 .deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woogon; Kim, Minhwan; Kim, Yongwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jaeyoung; Ekaputra, I. M. W. [Pukyong National Univ., Busan (Korea, Republic of)

    2014-05-15

    The VHTR components are designed to be used for a 60 year lifetime at a high temperature, the creep crack growth (CCG) behavior as well as creep behavior is very important for the design application due to creep damage during the long service life at elevated temperatures. Alloy 617 is a major candidate material for the IHX component. The design of the component, which will operate well into the creep range, will require a good understanding of creep crack growth deformation. Efforts are now being undertaken in the Generation IV program to provide data needed for the design and licensing of the nuclear plants, and with this goal in mind, to meet the needs of the conceptual designers of the VHTR system, 'Gen-IV Materials Handbook DB' is being established through an international collaboration program of several GIF (Gen-IV Forum) countries. CCG experimental data should be prepared to 'the Gen-IV Materials Handbook DB' website, because the CCG data for Alloy 617 are not available in the ASME design code. In this paper, experimental creep crack growth data were obtained through a series of CCG tests performed under different applied loads at 800 .deg. C. The CCG behavior was characterized in terms of the C{sup *} fracture mechanics parameter, and the CCGR equation for Alloy 617 was presented. Experimental CCG data of Alloy 617 were obtained from a series of creep crack growth tests under different applied loads at 800 .deg. C.

  19. On th meridional surface profile of the Gulf Stream at 55 deg W

    Science.gov (United States)

    Hallock, Zachariah R.; Teague, William J.

    1995-01-01

    Nine-month records from nine inverted echo sounders (IESs) are analyzed to describe the mean baroclinic Gulf Stream at 55 deg W. IES acoustic travel times are converted to thermocline depth which is optimally interpolated. Kinematic and dynamic parameters (Gulf Stream meridional position, velocity, and vorticity) are calculated. Primary Gulf Stream variabiltiy is attributed to meandering and and changes in direction. A mean, stream-coordinate (relative to Gulf Stream instantaneous position and direction) meridional profile is derived and compared with results presented by other investigators. The mean velocity is estimated at 0.84 m/s directed 14 deg to the right eastward, and the thermocline (12 c) drops 657 m (north to south), corresponding to a baroclinic rise of the surface of 0.87 m. The effect of Gulf Stream curvature on temporal mean profiles is found to be unimportant and of minimal importance overall. The derived, downstream current profile is well represented by a Gaussian function and is about 190 km wide where it crosses zero. Surface baroclinic transport is estimated to be 8.5 x 10(exp 4) sq m/s, and maximum shear (flanking the maximum) is 1.2 x 10(exp -5). Results compare well with other in situ observational results from the same time period. On the other hand, analyses (by others) of concurrent satellite altimetry (Geosat) suggest a considerable narrower, more intense mean Gulf Stream.

  20. Selecting Eco-Friendly Thermal Systems for the “Vittoriale Degli Italiani” Historic Museum Building

    Directory of Open Access Journals (Sweden)

    Davide Astiaso Garcia

    2015-09-01

    Full Text Available Thermal systems installed in museums should guarantee the maintenance of the optimal hygrothermal parameters ranges for the conservation of their collection materials. Considering the preservation of historic buildings, according to their historical and landscaping constraints, not all the thermal system typologies could be installed in these buildings’ typologies. Therefore, the main aim of this paper is to present some indications for the choice of the best thermal system solutions for a considered historic museum building, called Vittoriale degli Italiani, in the north of Italy, taking into account their installation feasibility and their related environmental impacts. The methodology includes a monitoring of the current hygrothermal parameters as well as the assessment of design heat and cooling loads related to the maintenance of the optimal hygrothermal parameters ranges for the conservation of collection materials. In addition, a Life Cycle Assessment (LCA of each selected system typology is considered for highlighting the most eco-friendly solution among the suitable ones. The obtained results highlights the feasible thermal system solutions able to maintain the hygrothermal parameters between the optimal ranges with a lower environmental impact in the Vittoriale degli Italiani historic museum building.

  1. The segregation of starless and protostellar clumps in the Hi-GAL l=224deg region

    CERN Document Server

    Olmi, L; Elia, D; Jones, P

    2016-01-01

    Stars form in dense, dusty structures, which are embedded in larger clumps of molecular clouds often showing a clear filamentary structure on large scales (> 1pc). One of the best-studied regions in the Hi-GAL survey can be observed toward the l=224deg field. Here, a filamentary region has been studied and it has been found that protostellar clumps are mostly located along the main filament, whereas starless clumps are detected off this filament and are instead found on secondary, less prominent filaments. We want to investigate this segregation effect and how it may affect the clumps properties. We mapped the 12CO(1-0) line and its main three isotopologues toward the two most prominent filaments observed toward the l=224deg field using the Mopra radio telescope, in order to set observational constraints on the dynamics of these structures and the associated starless and protostellar clumps. Compared to the starless clumps, the protostellar clumps are more luminous, more turbulent and lie in regions where the...

  2. Corrosion of stainless steels in lead-bismuth eutectic up to 600 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Soler, L. [Dpto. Fision Nuclear, CIEMAT, Edificio 30, Avda. Complutense 22, Madrid 28040 (Spain)]. E-mail: laura.soler@ciemat.es; Martin, F.J. [Dpto. Fision Nuclear, CIEMAT, Edificio 30, Avda. Complutense 22, Madrid 28040 (Spain); Hernandez, F. [Dpto. Fision Nuclear, CIEMAT, Edificio 30, Avda. Complutense 22, Madrid 28040 (Spain); Gomez-Briceno, D. [Dpto. Fision Nuclear, CIEMAT, Edificio 30, Avda. Complutense 22, Madrid 28040 (Spain)

    2004-11-01

    An experimental program has been carried out to understand the differences in the corrosion behaviour between different stainless steels: the austenitic steels 304L and 316L, the martensitic steels F82Hmod, T91 and EM10, and the low alloy steel P22. The influence of oxygen level in Pb-Bi, temperature and exposure time is studied. At 600 deg. C, the martensitic steels and the P22 steel exhibit thick oxide scales that grow with time, following a linear law for the wet environment and a parabolic law for the dry one. The austenitic stainless steels show a better corrosion behaviour, especially AISI 304L. Under reducing conditions, the steels exhibit dissolution, more severe for the austenitic stainless steels. At 450 deg. C, all the materials show an acceptable behaviour provided a sufficient oxygen level in the Pb-Bi. At reducing conditions, the martensitic steels and the P22 steel have a good corrosion resistance, while the austenitic steels exhibit already dissolution at the longer exposures.

  3. Searching for dark matter halos in the Suprime-Cam 2 sq deg field

    CERN Document Server

    Miyazaki, S; Shimasaku, K; Furusawa, H; Doi, M; Hamabe, M; Imi, K; Kimura, M; Komiyama, Yu; Nakata, F; Okada, N; Okamura, S; Ouchi, M; Sekiguchi, M; Yagi, M; Yasuda, N

    2002-01-01

    We report the first result of weak gravitational lensing survey on a 2.1 sq deg Rc-band image taken with a wide field camera (Suprime-Cam) on the prime focus of 8.2 m Subaru Telescope. The weak lensing mass reconstruction is applied to the data to search for dark matter halos of cluster scale; M >= 10^14 solar mass. The reconstructed convergence field is divided by 1-sigma noise to obtain the signal-to-noise ratio map (S/N-map) of the detection. Local maxima and minima are searched on the S/N-map and the probability distribution function (PDF) of the peaks are created to compare with model predictions. We found excess over noise PDF created from the randomized realization on both positive and negative sides. Negative peaks imply the presence of voids in the dark matter distribution and this is the first report of the detection. Positive peaks, on the other hand, represent the dark matter halos and the number count of the halos on the 2.1 sq deg image is 4.9 +- 2.3 for S/N > 5 where the Gaussian smoothing radi...

  4. La partecipazione degli enti ecclesiastici cattolici alle società di capitali

    Directory of Open Access Journals (Sweden)

    Ludovica Decimo

    2015-01-01

    Full Text Available SOMMARIO: 1. Valutazioni preliminari e nuove prospettive d’indagine – 2. L’attività negoziale degli enti ecclesiastici: le autorizzazioni canoniche – 3. La rilevanza dei controlli canonici nell’ordinamento italiano – 4. L’omissione delle autorizzazioni canoniche nella fase costitutiva della s.p.a. e della s.r.l. – 5. I controlli canonici e la circolazione delle azioni della s.p.a. – 6. La cessione di quote di s.r.l. in assenza delle autorizzazioni canoniche – 7. L’invalidità delle delibere peggiorative della situazione patrimoniale dell’ente ecclesiastico (l’aumento reale di capitale, la fusione, la trasformazione regressiva – 8. La partecipazione dell’ente ecclesiastico socio all’assemblea societaria: brevi cenni sulla rappresentanza delle persone giuridiche canoniche – 9. Il falsus procurator dell’ente ecclesiastico socio in assemblea ordinaria – 10. Ipotesi concrete di partecipazione degli enti ecclesiastici cattolici alle società di capitali, in particolare, alle s.r.l. – 11. L’assenza delle autorizzazioni canoniche nell’atto costitutivo della società “Tabor S.r.l.” – 12. L’errata individuazione delle autorizzazioni canoniche necessarie nell’atto costitutivo della società “G.M.G. E.R. Rinnovabili S.r.l. Unipersonale”.

  5. InAs 2DEGs:What's the g-factor?

    Science.gov (United States)

    McCombe, B. D.; Pakmehr, Mehdi; Khaetskii, A.; Chiatti, Olivio; Fischer, S. F.; Buchholz, S.; Heyn, C.; Hansen, W.; Cahay, M.; Newrock, R. S.; Bandari, Nikhil

    2014-03-01

    Interest in spin-orbit effects in semiconductors has led us to study the electron g-factor in quasi-2DEG InAs samples. We have made magneto-transport and -photoresponse (PR) measurements on InAs QW structures in magnetic fields up to 10 T. THz cyclotron resonance (CR) is manifested in PR as a resonant envelope of the amplitude of quantum oscillations, which show clear spin-splitting (for lower mobility samples) down 4T, while direct R_xx measurements show no spin-splitting up to 9T. R_xx oscillations in a higher mobility sample show well-resolved spin-splittings over a range of fields as does the PR. We have simulated the data with a theoretical expression for 2DEG SdH oscillations (coupled with CR resonant carrier heating for the PR) and extracted g-factors from fits. We also used a different (commonly used) method, SdH oscillations vs. tilt angle of the field to extract g-factors from the angle at which the SdH frequency doubles. We find very large g-factors from fits to R_xx and PR (14 - 20), but g-factors 2-3 times smaller for these same samples from tilted field experiments (close to estimated band g-factors). These results are discussed in terms of exchange effects. Support: NSF DMR 1008138 (Buffalo); NSF ECCE 1028483(Cincinnati); DFG Fi932/4-1(Berlin).

  6. Formation scenarios for the young stellar associations between galactic longitudes l = 280-360 deg

    CERN Document Server

    Sartori, M J; Dias, W S; Sartori, Marilia J.; Lepine, Jacques R. D.; Dias, Wilton S.

    2003-01-01

    We investigate the spatial distribution, the space velocities and age distribution of the pre-main sequence (PMS) stars belonging to Ophiuchus, Lupus and Chamaeleon star-forming regions (SFRs), and of the young early-type star members of the Scorpius-Centaurus OB association. These young stellar associations extend over the galactic longitude range from 280 deg. to 360 deg., and are at a distance interval of around 100 and 200 pc. The study is based on a compilation of distances, proper motions and radial velocities from the literature for the kinematic properties, and of basic stellar data for the construction of Hertzsprung-Russel diagrams. Although there was no well-known OB association in Chamaeleon, the distances and the proper motions of a group of 21 B- and A-type stars, taken from the Hipparcos Catalogue, lead us to propose that they form a young association. We show that the young early-type stars of the OB associations and the PMS stars of the SFRs follow a similar spatial distribution, i.e., there ...

  7. L’evoluzione cerebrale degli ominidi: quando antropologia, paleontologia e psicologia convergono su una domanda

    Directory of Open Access Journals (Sweden)

    Christian Agrillo

    2008-06-01

    Full Text Available Lo studio dell’evoluzione cerebrale degli ominidi rappresenta uno dei punti di arrivo di diverse discipline che pongono l’essere umano al centro del proprio interesse: la paleontologia, che si serve dei reperti fossili per evincere la storia evolutiva del cranio e del cervello; l’antropologia, che utilizza utensili e tradizioni di culture differenti per accostarsi anche allo studio della cognizione umana e infine la psicologia che - attraverso il confronto con le capacità cognitive di altri primati - si propone di indagare l’unicità o meno delle potenzialità mentali di cui disponiamo, alla ricerca di elementi condivisi dai nostri parenti più prossimi evolutisi in una diversa regione del continente africano.Comprendere quali siano state le cause che hanno diversificato il cammino dell’Uomo da quello degli altri primati significa, in primo luogo, capire quali fattori costituiscano effettivamente una prerogativa della specie umana, cosa ci differenzia dalle scimmie e come questo possa essere avvenuto. Diverse teorie sono state ipotizzate al riguardo: il presente lavoro riassume le principali visioni correnti, ponendo l’una di fronte l’altra e suggerendo come la mente umana possa essersi evoluta in seguito alla compresenza di più fattori che hanno spinto verso la medesima direzione, a differenza di quanto avvenuto per le scimmie antropomorfe.

  8. Interplay of Rashba and sp-d exchange couplings in magnetic 2DEGs

    Science.gov (United States)

    Mireles, Francisco; Freire, Henrique H. P.; Egues, J. Carlos

    2006-03-01

    In diluted magnetic semiconductor (DMS) quantum wells the sp-d exchange interaction between the itinerant conduction electrons in the well and the localized electrons in the d orbitals of the Mn impurities gives rise to interesting spin-dependent physics [1]. Recently, the interplay of the Rashba spin-orbit and the sp-d exchange interactions in Mn-based wells has been recognized via Shubnikov-de-Haas measurements [2]. While the Rashba spin-orbit has been extensively studied in non-magnetic 2DEGs, its role in DMS systems with a competing sp-d exchange interaction has not yet been addressed theoretically. In this work we present a k.p derivation of an effective Hamiltonian for a Mn-based quantum well with competing Rashba and sp-d interactions, and show numerical results for the magnetoresistance ρxx of typical magnetic 2DEGs using our effective Hamiltonian model. Our results shows interesting beating patterns of the ρxx as a function of the temperature and carrier density which suggests a significant interplay between the spin-orbit and sp-d exchange interactions, as a recent experiment observes [2]. [1] J. C. Egues, PRL 78, 4578 (1998); H. J. P. Freire and J. C. Egues, cond-mat/0412491. [2] Y. S. Gui et al. EPL. 65, 393 (2004).

  9. The p-wave superconductivity in the presence of Rashba interaction in 2DEG.

    Science.gov (United States)

    Weng, Ke-Chuan; Hu, C D

    2016-07-26

    We investigate the effect of the Rashba interaction on two dimensional superconductivity. The presence of the Rashba interaction lifts the spin degeneracy and gives rise to the spectrum of two bands. There are intraband and interband pairs scattering which result in the coupled gap equations. We find that there are isotropic and anisotropic components in the gap function. The latter has the form of cos φk where . The former is suppressed because the intraband and the interband scatterings nearly cancel each other. Hence, -the system should exhibit the p-wave superconductivity. We perform a detailed study of electron-phonon interaction for 2DEG and find that, if only normal processes are considered, the effective coupling strength constant of this new superconductivity is about one-half of the s-wave case in the ordinary 2DEG because of the angular average of the additional in the anisotropic gap function. By taking into account of Umklapp processes, we find they are the major contribution in the electron-phonon coupling in superconductivity and enhance the transition temperature Tc.

  10. Phase transition in non-brownian fiber suspensions

    Science.gov (United States)

    Franceschini, Alexandre; Filippidi, Emmanouella; Guazzelli, Elizabeth; Pine, David

    2012-11-01

    The simple shear of a suspension of fibers tends to align them with the flow direction. We previously reported that the oscillatory shear of neutrally buoyant non-Brownian fibers align them with the vorticity (Franceschini A. et al. PRL, 2011). We interpreted this phenomenon as the minimization of a ``corrected volume fraction'' defined as a function of the strain amplitude, the average orientation and the volume fraction. Below a critical value of this parameter, the system becomes fully reversible after a few periods. Above it, fluctuations remain and the fibers align with the vorticity, subsequently reducing the value of this corrected volume fraction. We present here the collective behavior of fibers constrained at the liquid-air interface. By pinning the liquid on the wall of a Couette cell, we can have a flat interface. By modifying the surface of the fibers, we get rid of most of surface tension mediated fiber-fiber interactions. In this 2D configuration we can measure spatial correlations, as well as the position and orientation of every fiber at each shear cycle. We similarly define a ``corrected surface fraction'' and see how this parameter help us understand the difference between the surface behavior and the suspension behavior. This work was supported by the NSF through the NYU MRSEC, Award DMR:0820341. Additional support was provided by a Lavoisier Fellowship (AF) and from the Onassis Foundation (EF).

  11. Entrepreneurial Orientation and Internationalisation

    DEFF Research Database (Denmark)

    Decker, Arnim; Rollnik-Sadowska, Ewa; Servais, Per

    Entrepreneurial orientation is a multidimensional construct that determines the strategic posture of a firm. In this study we investigate a sample of six manufacturing firms which are located both in a remote area and in a transition economy. Through interpreting the construct of entrepreneurial...... orientation as an attitude held by principals we investigate how entrepreneurial orientation affected the behaviour of these firms, specifically in terms of their internationalisation. Despite the fact that all firms have identical roots we find that entrepreneurial orientation held by their principals affect...

  12. All fiber optics circular-state swept source polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Lin, Hermann; Kao, Meng-Chun; Lai, Chih-Ming; Huang, Jyun-Cin; Kuo, Wen-Chuan

    2014-02-01

    A swept source (SS)-based circular-state (CS) polarization-sensitive optical coherence tomography (PS-OCT) constructed entirely with polarization-maintaining fiber optics components is proposed with the experimental verification. By means of the proposed calibration scheme, bulk quarter-wave plates can be replaced by fiber optics polarization controllers to, therefore, realize an all-fiber optics CS SSPS-OCT. We also present a numerical dispersion compensation method, which can not only enhance the axial resolution, but also improve the signal-to-noise ratio of the images. We demonstrate that this compact and portable CS SSPS-OCT system with an accuracy comparable to bulk optics systems requires less stringent lens alignment and can possibly serve as a technology to realize PS-OCT instrument for clinical applications (e.g., endoscopy). The largest deviations in the phase retardation (PR) and fast-axis (FA) angle due to sample probe in the linear scanning and a rotation angle smaller than 65 deg were of the same order as those in stationary probe setups. The influence of fiber bending on the measured PR and FA is also investigated. The largest deviations of the PR were 3.5 deg and the measured FA change by ~12 to 21 deg. Finally, in vivo imaging of the human fingertip and nail was successfully demonstrated with a linear scanning probe.

  13. Axon diameter mapping in crossing fibers with diffusion MRI

    DEFF Research Database (Denmark)

    Zhang, Hui; Dyrby, Tim B; Alexander, Daniel C

    2011-01-01

    tissue than measures derived from diffusion tensor imaging. Most existing techniques for axon diameter mapping assume a single axon orientation in the tissue model, which limits their application to only the most coherently oriented brain white matter, such as the corpus callosum, where the single...... orientation assumption is a reasonable one. However, fiber crossings and other complex configurations are widespread in the brain. In such areas, the existing techniques will fail to provide useful axon diameter indices for any of the individual fiber populations. We propose a novel crossing fiber tissue...... of the technique by establishing reasonable axon diameter indices in the crossing region at the interface of the cingulum and the corpus callosum....

  14. Accurate estimation of the elastic properties of porous fibers

    Energy Technology Data Exchange (ETDEWEB)

    Thissell, W.R.; Zurek, A.K.; Addessio, F.

    1997-05-01

    A procedure is described to calculate polycrystalline anisotropic fiber elastic properties with cylindrical symmetry and porosity. It uses a preferred orientation model (Tome ellipsoidal self-consistent model) for the determination of anisotropic elastic properties for the case of highly oriented carbon fibers. The model predictions, corrected for porosity, are compared to back-calculated fiber elastic properties of an IM6/3501-6 unidirectional composite whose elastic properties have been determined via resonant ultrasound spectroscopy. The Halpin-Tsai equations used to back-calculated fiber elastic properties are found to be inappropriate for anisotropic composite constituents. Modifications are proposed to the Halpin-Tsai equations to expand their applicability to anisotropic reinforcement materials.

  15. Amplitude-modulated fiber-ring laser

    DEFF Research Database (Denmark)

    Caputo, J. G.; Clausen, Carl A. Balslev; Sørensen, Mads Peter

    2000-01-01

    Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self-starting......Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self......-starting of stable solitonic pulses from small random noise, provided the modulation depth is small. The perturbative analysis leads to a nonlinear coupled return map for the amplitude, phase, and position of the soliton pulses circulating in the fiber-ring laser. We established the validity of this approach...

  16. Amplitude-modulated fiber-ring laser

    DEFF Research Database (Denmark)

    Caputo, J. G.; Clausen, Carl A. Balslev; Sørensen, Mads Peter

    2000-01-01

    Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self-starting......Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self......-starting of stable solitonic pulses from small random noise, provided the modulation depth is small. The perturbative analysis leads to a nonlinear coupled return map for the amplitude, phase, and position of the soliton pulses circulating in the fiber-ring laser. We established the validity of this approach...

  17. Optical Fiber Fusion Splicing

    CERN Document Server

    Yablon, Andrew D

    2005-01-01

    This book is an up-to-date treatment of optical fiber fusion splicing incorporating all the recent innovations in the field. It provides a toolbox of general strategies and specific techniques that the reader can apply when optimizing fusion splices between novel fibers. It specifically addresses considerations important for fusion splicing of contemporary specialty fibers including dispersion compensating fiber, erbium-doped gain fiber, polarization maintaining fiber, and microstructured fiber. Finally, it discusses the future of optical fiber fusion splicing including silica and non-silica based optical fibers as well as the trend toward increasing automation. Whilst serving as a self-contained reference work, abundant citations from the technical literature will enable readers to readily locate primary sources.

  18. Equations for estimating muscle fiber stress in the left ventricular wall.

    Science.gov (United States)

    Rabben, S I; Irgens, F; Angelsen, B

    1999-01-01

    Left ventricular muscle fiber stress is an important parameter in cardiac energetics. Hence, we developed equations for estimating regional fiber stresses in rotationally symmetric chambers, and equatorial and apical fiber stresses in prolate spheroidal chambers. The myocardium was modeled as a soft incompressible material embedding muscle fibers that support forces only in their longitudinal direction. A thin layer of muscle fibers then contributes with a pressure increment determined by the fiber stress and curvature. The fiber curvature depends on the orientation of the fibers, which varies continuously across the wall. However, by assuming rotational symmetry about the long axis of the ventricle and including a longitudinal force balance, we obtained equations where fiber stress is completely determined by the principal curvatures of the middle wall surface, wall thickness, and cavity pressure. The equations were validated against idealized prolate spheroidal chambers, whose wall thicknesses are such that the fiber stress is uniform from the equator to the apex. Because the apex is free to rotate, the resultant moment about the long axis of the LV must be zero. By using this constraint together with our fiber-stress equations, we were able to estimate a muscle fiber orientation distribution across the wall that was in qualitative agreement with published measurements.

  19. Effect of Fiber Waviness on Tensile Strength of a Flax-Sliver-Reinforced Composite Material

    Directory of Open Access Journals (Sweden)

    Taweesak Piyatuchsananon

    2015-01-01

    Full Text Available Recently, a composite material made from natural fibers and biodegradable resin, “green composite,” is attracting attention as an alternative composite material for the replacement of glass fiber-reinforced plastics. Plant-based natural fibers such as kenaf and flax have already been used as composite reinforcement materials because they are more environmentally friendly and costless fibers than artificial fibers. A problem of using natural fibers is the fiber waviness, which affects the tensile properties. Fiber waviness is fluctuation in the fiber orientation that is inherent in the sliver morphology of plant-based natural fibers. This study was conducted to clarify the relation between quantified parameters of fiber waviness and a composite’s tensile strength. First, the fiber orientation angles on a flax-sliver-reinforced composite were measured. Then the angle distribution was quantified through spatial autocorrelation analysis methods: Local Moran’s I and Local Geary’s c. Finally, the relation between the resultant tensile strength and quantified parameters was discussed.

  20. BD-22deg3467, a DAO-type Star Exciting the Nebula Abell 35

    Science.gov (United States)

    Ziegler, M.; Rauch, T.; Werner, K.; Koppen, J.; Kruk, J. W.

    2013-01-01

    Spectral analyses of hot, compact stars with non-local thermodynamical equilibrium (NLTE) model-atmosphere techniques allow the precise determination of photospheric parameters such as the effective temperature (T(sub eff)), the surface gravity (log g), and the chemical composition. The derived photospheric metal abundances are crucial constraints for stellar evolutionary theory. Aims. Previous spectral analyses of the exciting star of the nebula A35, BD-22deg3467, were based on He+C+N+O+Si+Fe models only. For our analysis, we use state-of-the-art fully metal-line blanketed NLTE model atmospheres that consider opacities of 23 elements from hydrogen to nickel. We aim to identify all observed lines in the ultraviolet (UV) spectrum of BD-22deg3467 and to determine the abundances of the respective species precisely. Methods. For the analysis of high-resolution and high signal-to-noise ratio (S/N) far-ultraviolet (FUSE) and UV (HST/STIS) observations, we combined stellar-atmosphere models and interstellar line-absorption models to fully reproduce the entire observed UV spectrum. Results. The best agreement with the UV observation of BD-22deg3467 is achieved at T(sub eff) = 80 +/- 10 kK and log g = 7.2 +/- 0.3. While T(sub eff) of previous analyses is verified, log g is significantly lower. We re-analyzed lines of silicon and iron (1/100 and about solar abundances, respectively) and for the first time in this star identified argon, chromium, manganese, cobalt, and nickel and determined abundances of 12, 70, 35, 150, and 5 times solar, respectively. Our results partially agree with predictions of diffusion models for DA-type white dwarfs. A combination of photospheric and interstellar line-absorption models reproduces more than 90% of the observed absorption features. The stellar mass is M approx. 0.48 Solar Mass. Conclusions. BD.22.3467 may not have been massive enough to ascend the asymptotic giant branch and may have evolved directly from the extended horizontal branch

  1. IL PORTFOLIO EUROPEO PER LA FORMAZIONE INIZIALE DEGLI INSEGNANTI (PEFIL COME STRUMENTO DI INSEGNAMENTO/APPRENDIMENTO

    Directory of Open Access Journals (Sweden)

    Adriana Arcuri

    2013-01-01

    Full Text Available Scopo di questo contributo è  descrivere il modo in cui il Pefil , Portfolio europeo per la formazione iniziale degli insegnanti di lingue. Uno strumento di riflessione (ECML, 2007 è stato usato nell’ambito del “Master in didattica dell’italiano come lingua non materna” dell’Università di Palermo non solo come strumento di autovalutazione, ma anche come strumento di insegnamento/apprendimento, valorizzando cioè  le potenzialità formative di questo Portfolio come auspicato dagli stessi autori.Il documento è impiegato, in una nuova prospettiva, come chiave di lettura dei contenuti della professione e ha fornito ai corsisti uno strumento per rintracciare le connessioni fra i diversi input formativi del Master. In questo modo è stato possibile per ciascuno di loro costruire un tessuto unitario di apprendimento delle competenze professionali di insegnanti di italiano L2 e LS  in un’ottica di life long learning, secondo un approccio riflessivo.  The Portfolio Europeo per la Formazione Iniziale degli Insegnanti (PEFIL as a teaching/learning tool The aim of this paper is to describe how the European Portfolio for Student Teachers of Languages - Portfolio Europeo per la Formazione Iniziale degli Insegnanti (PEFIL, A reflection tool for language teacher education (ECML, 2007 has been used in the Master Degree program in “Italian Foreign Language Teaching” at the University of Palermo. The PEFIL has not only been used as a tool for self-assessment, but by exploiting the educational potential of the portfolio, it has also become an important learning/teaching tool.The Portfolio was used as a way to interpret essential teaching contents. It gave students a tool for finding connections between the diverse educational elements of the Master program. Thus it was possible for each of them to create a coherent network of professional competences for teaching Italian as a second and foreign language within a life long learning

  2. The phase relations in the Gd-Fe-Ga ternary system at 500 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D.C. [College of Materials Science and Engineering, Shenzhen University and Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060 (China); Li, J.Q. [College of Materials Science and Engineering, Shenzhen University and Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060 (China)], E-mail: junqinli@szu.edu.cn; Ouyang, M.; Liu, F.S.; Ao, W.Q. [College of Materials Science and Engineering, Shenzhen University and Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060 (China)

    2009-06-24

    The isothermal section (500 deg. C) of the phase diagram of the Gd-Fe-Ga ternary system was investigated by X-ray powder diffraction analysis. Eleven binary compounds, GdGa{sub 2}, GdGa, Gd{sub 3}Ga{sub 2}, Gd{sub 5}Ga{sub 3}, GdFe{sub 2}, GdFe{sub 3}, Gd{sub 2}Fe{sub 17}, Fe{sub 3}Ga, Fe{sub 6}Ga{sub 5}, Fe{sub 3}Ga{sub 4} and FeGa{sub 3}, have been confirmed. Two ternary compounds, GdFe{sub 5.3}Ga{sub 6.7} and GdFe{sub 5}Ga{sub 7}, were found in this ternary system at 500 deg. C. The compound GdFe{sub 5.3}Ga{sub 6.7} is orthorhombic ScFe{sub 6}Ga{sub 6}-type structure (space group Immm) with a = 0.8567 (9), b = 0.86960 (9) and c = 0.50782 (5) nm, while the compound GdFe{sub 5}Ga{sub 7} is tetragonal ThMn{sub 12}-type structure (space group I4/mmm) with a = 0.8651(1) and c = 0.50934 (6) nm. The isothermal section at 500 deg. C consists of 16 single-phase regions, 31 two-phase regions and 16 three-phase regions. The maximum solid solubilities of Ga in GdFe{sub 2}, GdFe{sub 3}, Gd{sub 2}Fe{sub 17} are 9.2, 9.0, and 44.3 at.% respectively. The homogeneity range of GdGa{sub 2} is from 22 to 33.3 at.% Ga in Gd-Ga side but the solid solubility of Fe in this compound is very small. The homogeneity range of GdFe{sub 5}Ga{sub 7} is from 53.8 to 59.2 at.% Ga. Very limited solid solutions were measured in the other compounds.

  3. Sexual Orientation and Choice

    Directory of Open Access Journals (Sweden)

    Ayala Saray

    2017-07-01

    Full Text Available Is there a choice in sexual orientation? [Wilkerson, William S. (2009: “Is It a Choice? Sexual Orientation as Interpretation”. In: Journal of Social Philosophy 40. No. 1, p. 97–116] argues that sexual desires require interpretation in order to be fully constituted, and therefore sexual orientation is at least partially constituted by choice. [Díaz-León, Esa (2017: “Sexual Orientation as Interpretation? Sexual Desires, Concepts, and Choice”; In: Journal of Social Ontology] critically assesses Wilkerson’s argument, concluding that we still lack a good argument for the claim that choice plays a role in sexual orientation. Here I examine Díaz-León’s response to Wilkerson. I introduce what I call the conceptual act theory of sexual orientation, and argue that even if interpretation were not necessary to constitute sexual desires, it is a necessary element to constitute what we call sexual orientation. However, I conclude that even if we agree that interpretation is involved in sexual orientation, it does not follow that there is a choice involved.

  4. Edward Said and "Orientalism"

    Science.gov (United States)

    Chronicle of Higher Education, 2007

    2007-01-01

    In the nearly 30 years since Edward Said published the hugely influential Orientalism, his indictment of racism and imperialism in Western scholarship on the Orient has had its share of plaudits and condemnations. Now Robert Irwin, the Middle East editor of The Times Literary Supplement, has reignited the controversy with his broadside against the…

  5. Orientalism/Occidentalism

    NARCIS (Netherlands)

    Minca, C.; Ong, C.E.

    2017-01-01

    Orientalism and Occidentalism are interrelated concepts. Orientalism is defined in three keys ways: (i) as a study of “the Orient”; (ii) as a cultural and aesthetic concern with “the Orient”; and (iii) as a critical approach to understanding the construction of “the Orient” by European and American

  6. Teaching Orienteering. Second Edition.

    Science.gov (United States)

    McNeill, Carol; Cory-Wright, Jean; Renfrew, Tom

    The educational value provided by orienteering's blend of navigational and physical skills has given it a permanent place in the primary and secondary school curriculum in the United Kingdom. This book is a reference to orienteering for teachers, leaders, and coaches. It provides a "how to" approach to introducing and developing the…

  7. Orienteering in Camping.

    Science.gov (United States)

    Larson, Elston F.

    One of the recent developments in camping is "orienteering", a program using a map and compass. Orienteering can be dovetailed into an overall camping program and used to "point up" the entire program, or it can be confined to a single simple game. The arrangement depends on the situation. The minimum age of the participants should be about 9 or…

  8. Decision Making In Orienteering.

    Science.gov (United States)

    Almeida, Katia

    1997-01-01

    Eight psychometric instruments were administered to 10 elite male Portuguese orienteers. The cognitive process involved in decision making did not differ between the best orienteers and the others. This group of athletes had a high capacity for work realization and a strong need to be in control of interpersonal situations. (Author/SV)

  9. Wildlife value orientations

    DEFF Research Database (Denmark)

    Gamborg, Christian; Jensen, Frank Søndergaard

    2016-01-01

    This article examined value orientations toward wildlife among the adult general Danish public in relation to age, sex, past and present residence, education, and income, using a U.S. survey instrument on Wildlife Value Orientations (WVO). The study used an Internet-based questionnaire sent...

  10. Hybrid solar cell on a carbon fiber

    Science.gov (United States)

    Grynko, Dmytro A.; Fedoryak, Alexander N.; Smertenko, Petro S.; Dimitriev, Oleg P.; Ogurtsov, Nikolay A.; Pud, Alexander A.

    2016-05-01

    In this work, a method to assemble nanoscale hybrid solar cells in the form of a brush of radially oriented CdS nanowire crystals around a single carbon fiber is demonstrated for the first time. A solar cell was assembled on a carbon fiber with a diameter of ~5-10 μm which served as a core electrode; inorganic CdS nanowire crystals and organic dye or polymer layers were successively deposited on the carbon fiber as active components resulting in a core-shell photovoltaic structure. Polymer, dye-sensitized, and inverted solar cells have been prepared and compared with their analogues made on the flat indium-tin oxide electrode.

  11. PULP FIBER SIZE CHARACTERIZATION

    Institute of Scientific and Technical Information of China (English)

    Shijie Liu

    2004-01-01

    Pulp fiber length distribution characterization has been examined in this study. Because of the fiber morphology: slender in shape, fiber size distribution characterization is a very difficult task. Traditional technique involves separation of the particles by size,such as Bauer-McNett fiber classifier, and measuring the weight fractions. The particle fractions obtained may or may not reflect the desired size classification.On the other hand, the more recent technique through optical measurement of fiber length is limited by its inability to measure the mass of the particle fractions.Therefore, not only the two techniques fail to generate identical results, either one was accepted to be of better value. Pure hardwood kraft, softwood kraft, and their mixture samples have been measured for their fiber length distributions using an optical fiber quality analyzer: FQA. The data obtained from FQA are extensively studied to investigate more reliable way of representing the fiber length data and thus examining the viable route for measuring the fiber size distributions. It has been found that the fiber length averaged length 11 is a viable indicator of the average pulp fiber length. The fiber size fraction and/or distribution can be represented by the fiber "length" fractions.

  12. Properties of PAN Fibers Solution Spun into a Chilled Coagulation Bath at High Solvent Compositions

    National Research Council Canada - National Science Library

    Morris, E; Weisenberger, Matthew; Rice, Gregory

    2015-01-01

    ...), while carefully altering the composition of the coagulation bath, in order to determine the effect on the resulting fiber shape, density, orientation, and tensile properties at varying points in the spinning process...

  13. Optimal design of variable-stiffness fiber-reinforced composites using cellular automata

    NARCIS (Netherlands)

    Setoodeh, S.

    2005-01-01

    Growing number of applications of composites materials in aerospace and naval structures along with advancements in manufacturing technologies demand continuous innovations in design of composite structures. In the traditional design of composite laminates, fiber orientation angles are constant for

  14. Solving the "Magic Angle" Challenge in Determining Molecular Orientation at Interfaces

    CERN Document Server

    Li, Zhiguo; Li, Yingmin; Xiong, Wei

    2016-01-01

    We introduce a method to unambiguously determine the net molecular orientation (both mean tilt angle and orientation distribution) of molecules at interfaces using heterodyned two-dimensional sum frequency generation spectroscopy. By doing so, we have solved the long-standing "magic angle" challenge, i.e. the measurement of molecular orientation using one-dimensional sum frequency generation often assumes a narrow orientation distribution that results in ambiguity in tilt angle measurement. We applied our new method to a catalyst/electrode interface. In particular, it is found that Re(4,4'-dicyano-2,2'-bipyridine)(CO)3Cl formed a relatively-ordered monolayer on a gold slide, which has a mean tilt angle between the C3 symmetric axis of the catalysts and the surface normal of 52{\\deg}, with a non-negligible 11{\\deg} orientation distribution. Although applied to a specific system, this method is a general way to determine the orientations of an ensemble-averaged molecular surface, which can potentially be applie...

  15. Gian Piero Piretto, La vita privata degli oggetti sovietici. 25 storie da un altro mondo

    Directory of Open Access Journals (Sweden)

    Enza Dammiano

    2013-05-01

    Full Text Available Dopo aver analizzato le “mitologie culturali” dell’era sovietica – il “radioso avvenire” che queste proiettavano (Il radioso avvenire. Mitologie culturali sovietiche, Einaudi, 2001 – e ‘illustrato’, in particolare, gli anni Trenta e Quaranta attraverso Gli occhi di Stalin (Raffaello Cortina, 2010, con La vita privata degli oggetti sovietici Gian Piero Piretto introduce il lettore nelle “storie” di venticinque «cose sovietiche» (32, disseminate lungo l’intero arco temporale di esistenza dell’URSS e oltre: «La maggior parte delle cose a cui dedicherò la mia specifica attenzione ancora circola […], talora in forme rinnovate (degenerate o adattate alla nuova realtà» (43.

  16. A 20 GHz Bright Sample for Delta > 72 deg - II. Multi-frequency Follow-up

    CERN Document Server

    Ricci, R; Verma, R; Prandoni, I; Carretti, E; Mack, K -H; Massardi, M; Procopio, P; Zanichelli, A; Gregorini, L; Mantovani, F; Gawronski, M P; Peel, M W

    2013-01-01

    We present follow-up observations at 5, 8 and 30 GHz of the K-band Northern Wide Survey (KNoWS) 20 GHz Bright Sample, performed with the 32-m Medicina Radio Telescope and the 32-m Torun Radio Telescope. The KNoWS sources were selected in the Northern Polar Cap (Delta > 72 deg) and have a flux density limit S(20GHz) = 115 mJy. We include NVSS 1.4 GHz measurements to derive the source radio spectra between 1.4 and 30 GHz. Based on optical identifications, 68 per cent of the sources are QSOs, and 27 per cent are radio galaxies. A redshift measurement is available for 58 per cent of the sources. The radio spectral properties of the different source populations are found to be in agreement with those of other high-frequency selected samples.

  17. Modeling and computation of flow in a passage with 360 deg turning and multiple airfoils

    Science.gov (United States)

    Shyy, W.; Vu, T. C.

    1991-06-01

    Numerical modeling of the three-dimensional flows in a spiral casing of a hydraulic turbine, containing a passage of 360-deg turning and multiple elements of airfoils (the so-called distributor), is made. The physical model is based on a novel two-level approach, comprising of (1) a global model that adequately accounts for the geometry of the spiral casing but smears out the details of the distributor and represents the multiple airfoils by a porous medium treatment; and (2) a local model that performs detailed analysis of flow in the distributor region. The global analysis supplies the inlet flow condition for the individual cascade of distributor airfoils, while the distributor analysis yields the information needed for modeling the characteristics of the porous medium. Comparisons of pressure and velocity profiles between measurement and prediction have been made to assess the validity of the present approach. Flow characteristics in the spiral casing are also discussed.

  18. Constraining the Absolute Orientation of eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission

    Science.gov (United States)

    Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.

    2011-01-01

    We present a three-dimensional (3-D) dynamical model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA(theta) that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38deg, and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i approx. = 130deg to 145deg, Theta approx. = -15deg to +30deg, and an orbital axis projected on the sky at a P A approx. = 302deg to 327deg east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3-D. The companion star, Eta(sub B), thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modeling to determine the stellar masses.

  19. Understanding fiber mixture by simulation in 3D Polarized Light Imaging.

    Science.gov (United States)

    Dohmen, Melanie; Menzel, Miriam; Wiese, Hendrik; Reckfort, Julia; Hanke, Frederike; Pietrzyk, Uwe; Zilles, Karl; Amunts, Katrin; Axer, Markus

    2015-05-01

    3D Polarized Light Imaging (3D-PLI) is a neuroimaging technique that has opened up new avenues to study the complex architecture of nerve fibers in postmortem brains. The spatial orientations of the fibers are derived from birefringence measurements of unstained histological brain sections that are interpreted by a voxel-based analysis. This, however, implies that a single fiber orientation vector is obtained for each voxel and reflects the net effect of all comprised fibers. The mixture of various fiber orientations within an individual voxel is a priori not accessible by a standard 3D-PLI measurement. In order to better understand the effects of fiber mixture on the measured 3D-PLI signal and to improve the interpretation of real data, we have developed a simulation method referred to as SimPLI. By means of SimPLI, it is possible to reproduce the entire 3D-PLI analysis starting from synthetic fiber models in user-defined arrangements and ending with measurement-like tissue images. For the simulation, each synthetic fiber is considered as an optical retarder, i.e., multiple fibers within one voxel are described by multiple retarder elements. The investigation of different synthetic crossing fiber arrangements generated with SimPLI demonstrated that the derived fiber orientations are strongly influenced by the relative mixture of crossing fibers. In case of perpendicularly crossing fibers, for example, the derived fiber direction corresponds to the predominant fiber direction. The derived fiber inclination turned out to be not only influenced by myelin density but also systematically overestimated due to signal attenuation. Similar observations were made for synthetic models of optic chiasms of a human and a hooded seal which were opposed to experimental 3D-PLI data sets obtained from the chiasms of both species. Our study showed that SimPLI is a powerful method able to test hypotheses on the underlying fiber structure of brain tissue and, therefore, to improve the

  20. Silica enhanced formation of hydroxyapatite nanocrystals in simulated body fluid (SBF) at 37 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Sadjadi, M.S., E-mail: m.s.sadjad@gmail.com [Department of Chemistry, Sciences and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Ebrahimi, H.R. [Department of Chemistry, Sciences and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Meskinfam, M. [Department of Chemistry, Tonekabon Branch, Islamic Azad University, Tonekabon (Iran, Islamic Republic of); Zare, K. [Department of Chemistry, University of Shahid Beheshti, Eveen Tehran (Iran, Islamic Republic of)

    2011-10-17

    Highlights: {yields} We report on fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in silica-containing simulated body fluid solution at 37 deg. C. {yields} Bioactivity and biodegradability of TCP precursor have been confirmed by the dissolution of TCP and formation of a bone like layer of new HA nanoparticles outside of the precursor after 24 h soaking in SBF solution. {yields} Successive nucleation and formation of tiny hexagonal HA nanoplates and nanorods have been confirmed by TEM results after 24 h soaking of TCP in silica-containing BSF solution. - Abstract: The chemical modification of implant (prosthesis) surfaces is being investigated worldwide for improving the fixation of orthopaedic and dental implants. The main goal in this surface modification approach is to achieve a faster bone growth and chemical bonding of the implant to the newly generated and/or remodeled bone. In this work, we report fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in simulated body fluid (SBF, inorganic components of human blood plasma) solutions at 37 deg. C, using calcium phosphate (TCP) and sodium silicate as precursors. Characterization and chemical analysis of the synthesized powders were performed by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated enhanced nucleation and formation of bone like layer of HA nanocrystals at the surface of TCP nanoparticles and occurrence of HA nanocrystals during 24 h soaking of TCP in SBF solution containing silica ions. The average size of a nanoparticle, using Scherrer formula, was found to be 18.2 nm.

  1. Nonlinear Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Hansen, Kim Per

    2004-01-01

    Despite the general recession in the global economy and the collapse of the optical telecommunication market, research within specialty fibers is thriving. This is, more than anything else, due to the technology transition from standard all-glass fibers to photonic crystal fibers, which, instead...... of doping, use a microstructure of air and glass to obtain a refractive index difference between the core and the cladding. This air/glass microstructure lends the photonic crystal fibers a range of unique and highly usable properties, which are very different from those found in solid standard fibers....... The freedom to design the dispersion profile of the fibers is much larger and it is possible to create fibers, which support only a single spatial mode, regardless of wavelength. In comparison, the standard dispersion-shifted fibers are limited by a much lower index-contrast between the core and the cladding...

  2. Glass Fibers: Quo Vadis?

    Directory of Open Access Journals (Sweden)

    Edith Mäder

    2017-02-01

    Full Text Available Since the early 1930s, the process of melting glass and subsequently forming fibers, in particular discontinuous fiber glass or continuous glass filaments, evolved into commercial-scale manufacturing.[...

  3. Fiber Optics Technology.

    Science.gov (United States)

    Burns, William E.

    1986-01-01

    Discusses various applications of fiber optics technology: information systems, industrial robots, medicine, television, transportation, and training. Types of jobs that will be available with fiber optics training (such as electricians and telephone cable installers and splicers) are examined. (CT)

  4. Fiber Optics Instrumentation Development

    Science.gov (United States)

    Chan, Patrick Hon Man; Parker, Allen R., Jr.; Richards, W. Lance

    2010-01-01

    This is a general presentation of fiber optics instrumentation development work being conducted at NASA Dryden for the past 10 years and recent achievements in the field of fiber optics strain sensors.

  5. Quantitative regulation of bone-mimetic, oriented collagen/apatite matrix structure depends on the degree of osteoblast alignment on oriented collagen substrates.

    Science.gov (United States)

    Matsugaki, Aira; Isobe, Yoshihiro; Saku, Taro; Nakano, Takayoshi

    2015-02-01

    Bone tissue has a specific anisotropic morphology derived from collagen fiber alignment and the related apatite crystal orientation as a bone quality index. However, the precise mechanism of cellular regulation of the crystallographic orientation of apatite has not been clarified. In this study, anisotropic construction of cell-produced mineralized matrix in vitro was established by initiating organized cellular alignment and subsequent oriented bone-like matrix (collagen/apatite) production. The oriented collagen substrates with three anisotropic levels were prepared by a hydrodynamic method. Primary osteoblasts were cultured on the fabricated substrates until mineralized matrix formation is confirmed. Osteoblast alignment was successfully regulated by the level of substrate collagen orientation, with preferential alignment along the direction of the collagen fibers. Notably, both fibrous orientation of newly synthesized collagen matrix and c-axis of produced apatite crystals showed preferential orientation along the cell direction. Because the degree of anisotropy of the deposited apatite crystals showed dependency on the directional distribution of osteoblasts cultured on the oriented collagen substrates, the cell orientation determines the crystallographic anisotropy of produced apatite crystals. To the best of our knowledge, this is the first report demonstrating that bone tissue anisotropy, even the alignment of apatite crystals, is controllable by varying the degree of osteoblast alignment via regulating the level of substrate orientation.

  6. Deformation of a flexible fiber in a viscous flow past an obstacle

    CERN Document Server

    Lopez, H M; Auradou, H; D'Angelo, M V

    2015-01-01

    We study the deformation and transport of elastic fibers in a viscous Hele-Shaw flow with curved streamlines. The variations of the global velocity and orientation of the fiber follow closely those of the local flow velocity. The ratios of the curvatures of the fibers by the corresponding curvatures of the streamlines reflect a balance between elastic and viscous forces: this ratio is shown experimentally to be determined by a dimensionless {\\it Sperm number} $Sp$ combining the characteristic parameters of the flow (transverse velocity gradient, viscosity, fiber diameter/cell gap ratio) and those of the fiber (diameter, effective length, Young's modulus). For short fibers, the effective length is that of the fiber; for long ones, it is equal to the transverse characteristic length of the flow. For $S\\_p \\lesssim 250$, the ratio of the curvatures increases linearly with $Sp$; For $S\\_p \\gtrsim 250$, the fiber reaches the same curvature as the streamlines.

  7. Ion exchange properties of titanic fiber of layered structure

    Energy Technology Data Exchange (ETDEWEB)

    Fujiki, Yoshinori; Komatsu, Yu; Sasaki, Takayoshi

    1986-12-01

    Usually, titanic acid is produced by hydrolyzing titanium tetrachloride, titanium sulfate or titanium alkoxide and is obtained in the form of precipitate in an amorphous gel state. The present authors have synthesized two types of titanic fibers of a layered crystaline structure to provide new ion exchangers. Three synthetic techniques, namely, flux process, annealing baking process and melt process, have been developed. This report deals with the structure and properties of these materials. In the flux process, a mixture of TiO/sub 2/, K/sub 2/CO/sub 3/ and K/sub 2/MoO/sub 4/ (flux) is melted at 1150 deg C and annealed at about 950 deg C to provide a K/sub 2/Ti/sub 4/O/sub 3/ fiber of a layered structure, which is subsequently converted into H/sub 2/Ti/sub 4/O/sub 9/ center dot nH/sub 2/O fiber. In the melt process, a mixture of materials is heate up to 1100 deg C to produce molten K/sub 2/Ti/sub 2/O/sub 5/, which is quenched to form K/sub 2/Ti/sub 2/O/sub 5/ fiber of a layered structure. Then it is converted into H/sub 2/Ti/sub 2/O/sub 5/ center dot nH/sub 2/O fiber. The annealing baking process provides K/sub 2/Ti/sub 4/O/sub 9/, which is converted into K/sub 2/Ti/sub 2/O/sub 5/ fiber. In this report, the crystal structure of H/sub 2/Ti/sub 4/O/sub 9/ center dot nH/sub 2/O is discussed and the ion exchanging properties are analized. Examination is made on the ion exchanging reactions involving potassium, alkali metal ions, alkaline earth metal ions and divalent transition metal ions. Various ion exchangers, including the present ones, are compared in terms of the partition coefficient and separation factor. (Nogami, K.).

  8. Effect of Substrate Doping in Relaxed SiGe Buffers on Strained Si 2DEG Quantum Devices

    Science.gov (United States)

    Yao, Kun; Gaevski, Mikhail; Chernyshov, Alexander; Rokhinson, Leonid; Mike, Curtin; Park, Ji-Soo; Fiorenza, James; Lochtefeld, Anthony; Sturm, James

    2009-03-01

    We describe the impact of Si substrate doping on the substrate leakage in strained Si two-dimensional electron gases (2DEG) on SiGe relaxed graded buffers and on quantum devices fabricated from the 2DEG. The best commercially available high quality SiGe relaxed buffers with 30% Ge content, grown at temperature above 1000^oC, have very low threading dislocation density (heterostructures were grown at 625-700^oC in a rapid thermal chemical vapor deposition (RTCVD). However, it is shown that the substrate doping (Arsenic) contributes to leakage current origin in relaxed buffers at liquid helium temperatures if the starting Si substrate is heavily doped (˜5E17cm-2). The leakage can be attributed to enhanced dopant diffusion along misfit dislocations and high diffusion rate of As in SiGe. The leakage current makes side gating of nanostructures in the 2DEG impossible. With a lightly doped substrate, to avoid leakage, we achieved a high quality 2DEG and successful side gating of a 2DEG quantum dot for a quantum point contact. This work is supported by the NSA under ARO contract number W911NF-05-1-0437.

  9. Fundamentals of fiber lasers and fiber amplifiers

    CERN Document Server

    Ter-Mikirtychev, Valerii (Vartan)

    2014-01-01

    This book covers the fundamental aspects of fiber lasers and fiber amplifiers, and includes a wide range of material from laser physics fundamentals to state-of-the-art topics in this rapidly growing field of quantum electronics. Emphasis is placed on the nonlinear processes taking place in fiber lasers and amplifiers, their similarities, differences to, and their advantages over other solid-state lasers. The reader will learn basic principles of solid-state physics and optical spectroscopy of laser active centers in fibers, main operational laser regimes, and practical recommendations and suggestions on fiber laser research, laser applications, and laser product development. The book will be useful for students, researchers, and professionals who work with lasers, in the optical communications, chemical and biological industries, etc.

  10. Polarization insensitive all-fiber mode-lockers functioned by carbon nanotubes deposited onto tapered fibers

    Science.gov (United States)

    Song, Yong-Won; Morimune, Keiyo; Set, Sze Y.; Yamashita, Shinji

    2007-01-01

    The authors demonstrate a nonblocked all-fiber mode locker operated by the interaction of carbon nanotubes with the evanescent field of propagating light in a tapered fiber. Symmetric cross section of the device with the randomly oriented nanotubes guarantees the polarization insensitive operation of the pulse formation. In order to minimize the scattering, the carbon nanotubes are deposited within a designed area around the tapered waist. The demonstrated passively pulsed laser has the repetition rate of 7.3MHz and the pulse width of 829fs.

  11. Use of fiber helical coils to obtain polarization insensitive fiber devices

    Science.gov (United States)

    Tentori, Diana; Garcia-Weidner, A.; Rodriguez-Garcia, J. A.

    2016-09-01

    Using a new model for the description of the birefringence of a helical coil, it is shown that the birefringence effect on the signal polarization introduced by a fiber device can be canceled out by introducing two helical coils at the required orientation. Experimental results obtained using this modification in a polarization insensitive device (optical isolator) and in a non-polarization insensitive device working at two different wavelengths (wavelength division multiplexer) are presented and discussed. Such modified devices were used in the construction of an erbium-doped fiber amplifier (EDFA) with a full control of the input signal and pump states of polarization.

  12. Oil sorption by lignocellulosic fibers

    Science.gov (United States)

    Beom-Goo. Lee; James S. Han; Roger M. Rowell

    1999-01-01

    The oil sorption capacities of cotton fiber, kenaf bast fiber, kenaf core fiber, and moss fiber were compared after refining, extraction, and reduction in particle sizes. The tests were conducted on diesel oil in a pure form. Cotton fiber showed the highest capacity, followed by kenaf core and bast fibers. Wetting, extraction, and reduction in particle size all...

  13. Network-oriented or user-oriented?

    Science.gov (United States)

    Tirro, S.

    1986-12-01

    Optimized communications satellite services are identified, with emphasis on the benefits of large, multiuser spacecraft and the complementary nature of satellite system relative to fiber optics. Consideration is given to DBS, data transfer and collection, fixed-point and mobile communications networks. The costs of the space and ground segments are explored, along with the associated tariff structure and techniques for predicting the associated income. It is assumed that the satellite systems backup ground-based systems and also provide new digital services. A methodology is presented for optimizing satellite systems in terms of the ground-based capabilities and costs, the projected traffic, and the iterative space segment costs.

  14. Whole Grains and Fiber

    Science.gov (United States)

    ... whole grains. Does not contain partially hydrogenated oils. Dietary Fiber Dietary fiber is the term for several materials that make ... water. When eaten regularly as part of a diet low in saturated fat and trans fat soluble fiber has been associated with increased diet quality and ...

  15. Resonant filtered fiber amplifiers

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Laurila, Marko; Olausson, Christina Bjarnal Thulin

    2013-01-01

    In this paper we present our recent result on utilizing resonant/bandgap fiber designs to achieve high performance ytterbium doped fiber amplifers for achieving diffraction limited beam quality in large mode area fibers, robust bending performance and gain shaping for long wavelength operation of...

  16. Mineral Fiber Toxicology

    Science.gov (United States)

    The chemical and physical properties of different forms of mineral fibers impact biopersistence and pathology in the lung. Fiber chemistry, length, aspect ratio, surface area and dose are critical factors determining mineral fiber-associated health effects including cancer and as...

  17. The Fiber Optic Connection.

    Science.gov (United States)

    Reese, Susan

    2003-01-01

    Describes the fiber optics programs at the Career and Technical Center in Berlin, Pennsylvania and the Charles S. Monroe Technology Center in Loudoun County, Virginia. Discusses the involvement of the Fiber Optic Association with education, research and development, manufacturing, sales, distribution, installation, and maintenance of fiber optic…

  18. Fiber Nonlinearities: A Tutorial

    Institute of Scientific and Technical Information of China (English)

    Govind P. Agrawal

    2003-01-01

    Fiber nonlinearities have long been regarded as being mostly harmful for fiber-optic communication systems. Over the last few years, however, the nonlinear effects are increasingly being used for practical telecommunications applications,the Raman amplification being only one of the recent examples. In this tutorial I review the vario us nonlinear effects occurring in optical fibers from both standpoints..

  19. Fiber Nonlinearities: A Tutorial

    Institute of Scientific and Technical Information of China (English)

    Govind; P.; Agrawal

    2003-01-01

    Fiber nonlinearities have long been regarded as being mostly harmful for fiber-optic communication systems. Over the last few years, however, the nonlinear effects are increasingly being used for practical telecommunications applications, the Raman amplification being only one of the recent examples. In this tutorial I review the various nonlinear effects occurring in optical fibers from both standpoints..

  20. Prime Focus Spectrograph for the Subaru telescope: massively multiplexed optical and near-infrared fiber spectrograph

    CERN Document Server

    Sugai, Hajime; Karoji, Hiroshi; Shimono, Atsushi; Takato, Naruhisa; Kimura, Masahiko; Ohyama, Youichi; Ueda, Akitoshi; Aghazarian, Hrand; de Arruda, Marcio Vital; Barkhouser, Robert H; Bennett, Charles L; Bickerton, Steve; Bozier, Alexandre; Braun, David F; Bui, Khanh; Capocasale, Christopher M; Carr, Michael A; Castilho, Bruno; Chang, Yin-Chang; Chen, Hsin-Yo; Chou, Richard C Y; Dawson, Olivia R; Dekany, Richard G; Ek, Eric M; Ellis, Richard S; English, Robin J; Ferrand, Didier; Ferreira, Décio; Fisher, Charles D; Golebiowski, Mirek; Gunn, James E; Hart, Murdock; Heckman, Timothy M; Ho, Paul T P; Hope, Stephen; Hovland, Larry E; Hsu, Shu-Fu; Hu, Yen-Shan; Huang, Pin Jie; Jaquet, Marc; Karr, Jennifer E; Kempenaar, Jason G; King, Matthew E; Fèvre, Olivier Le; Mignant, David Le; Ling, Hung-Hsu; Loomis, Craig; Lupton, Robert H; Madec, Fabrice; Mao, Peter; Marrara, Lucas Souza; Ménard, Brice; Morantz, Chaz; Murayama, Hitoshi; Murray, Graham J; de Oliveira, Antonio Cesar; de Oliveira, Claudia Mendes; de Oliveira, Ligia Souza; Orndorff, Joe D; Vilaça, Rodrigo de Paiva; Partos, Eamon J; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J; Riddle, Reed; Santos, Leandro; Santos, Jesulino Bispo dos; Schwochert, Mark A; Seiffert, Michael D; Smee, Stephen A; Smith, Roger M; Steinkraus, Ronald E; Sodré, Laerte; Spergel, David N; Surace, Christian; Tresse, Laurence; Vidal, Clément; Vives, Sebastien; Wang, Shiang-Yu; Wen, Chih-Yi; Wu, Amy C; Wyse, Rosie; Yan, Chi-Hung

    2015-01-01

    The Prime Focus Spectrograph (PFS) is an optical/near-infrared multifiber spectrograph with 2394 science fibers distributed across a 1.3-deg diameter field of view at the Subaru 8.2-m telescope. The wide wavelength coverage from 0.38 {\\mu}m to 1.26 {\\mu}m, with a resolving power of 3000, simultaneously strengthens its ability to target three main survey programs: cosmology, galactic archaeology and galaxy/AGN evolution. A medium resolution mode with a resolving power of 5000 for 0.71 {\\mu}m to 0.89 {\\mu}m will also be available by simply exchanging dispersers. We highlight some of the technological aspects of the design. To transform the telescope focal ratio, a broad-band coated microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of the cable system, optimizing overall throughput; a fiber with low focal ratio degradation is selected for the fiber-positioner and fiber-slit components, minimizing the effects of fiber movements and fiber bending. Fiber positioning ...