3,582 research outputs found
Wavelength tunable 10-GHz 3-ps pulse source using a dispersion decreasing fiber-based nonlinear optical loop mirror
No full textWe experimentally demonstrate the use of a dispersion decreasing fiber (DDF)-based nonlinear optical loop mirror (NOLM) for the generation of wavelength tunable soliton-like pulses at a repetition rate of 10 GHz. We compress ~12 ps Gaussian pulses from an electro-absorption modulator (EAM) (followed by 125 m of DCF for preliminary linear dispersion compensation) into 3 ps pedestal-free pulses using both high-order soliton compression and nonlinear switching effects within an 8.5 km DDF-based loop mirror. The output pulses from the DDF-based NOLM show considerable pedestal reduction compared to those obtained by directly compressing the EAM seed pulses via a single passage through the DDF. Wavelength tuning of the compressed pulses over a ~15 nm bandwidth (from 1541 to 1556 nm) is demonstrated without a significant increase in pulse duration or degradation in pulse quality
Player agency in interactive narrative: audience, actor & author
No full textThe question motivating this review paper is, how can
computer-based interactive narrative be used as a constructivist learn-
ing activity? The paper proposes that player agency can be used to
link interactive narrative to learner agency in constructivist theory,
and to classify approaches to interactive narrative. The traditional
question driving research in interactive narrative is, ‘how can an in-
teractive narrative deal with a high degree of player agency, while
maintaining a coherent and well-formed narrative?’ This question
derives from an Aristotelian approach to interactive narrative that,
as the question shows, is inherently antagonistic to player agency.
Within this approach, player agency must be restricted and manip-
ulated to maintain the narrative. Two alternative approaches based
on Brecht’s Epic Theatre and Boal’s Theatre of the Oppressed are
reviewed. If a Boalian approach to interactive narrative is taken the
conflict between narrative and player agency dissolves. The question
that emerges from this approach is quite different from the traditional
question above, and presents a more useful approach to applying in-
teractive narrative as a constructivist learning activity
Ss-traveltime Parameters From Pp And Ps Reflections
No full textThe SS-wave traveltimes can be derived from PP- and PS-wave data with the previously derived PP + PS = SS method. We have extended this method as follows. (1) The previous requirement that sources and receivers be located on a common acquisition surface is removed, which makes the method directly applicable to PS-waves recorded on the ocean bottom and PP-waves recorded at the ocean surface. (2) By using the concept and properties of surface-to-surface propagator matrices, the second-order traveltime derivatives of the SS-waves are obtained. In the same way as for the original PP + PS = SS method, the proposed extension is valid for arbitrary anisotropic media. The propagator matrix and geometric spreading of an SS-wave reflected at a given point on a target reflector are obtained explicitly from the propagators of the PP- and PS-waves reflected at the same point. These additional parameters provided by the extended PP + PS = SS method can be used for a partial reconstruction of the SS-wave amplitude as well as for tomographic estimation of the elastic velocity model. A full simulation of the SS-wave, which includes reflection and transmission coefficients, cannot be obtained directly from recorded PP- and PS-wave amplitudes. © 2009 Society of Exploration Geophysicists. All rights reserved.744R35R47Aki, K., Richards, P.G., (2002) Quantitative Seismology, , University Science BooksBortfeld, R., Geometrical ray theory: Rays and traveltimes in seismic systems (second-order approximations of the traveltimes) (1989) Geophysics, 54, pp. 342-349. , gpy GPYSA7 0016-8033 10.1190/1.1442659Červený, V., (2001) Seismic Ray Theory, , Cambridge University PressChapman, C.H., Reflection/transmission reciprocities in anisotropic media (1994) Geophysical Journal International, 116, pp. 498-501. , gji GJINEA 0956-540X 10.1111/j.1365-246X.1994.tb01811.xDai, H., Li, X.Y., Conway, P., Imaging beneath gas clouds using 3D prestack Kirchhoff time migration of PS-converted waves - A case study from the North Sea (2007) The Leading Edge, 26, pp. 522-529. , lee LEEDFF 1070-485X 10.1190/1.2723216Duveneck, E., 3D tomographic velocity model estimation with kinematic wavefield attributes (2004) Geophysical Prospecting, 52, pp. 535-545. , 8uc GPPRAR 0016-8025 10.1111/j.1365-2478.2004.00449.xFoss, S.-K., Ursin, B., de Hoop, M., Depth-consistent reflection tomography using PP and PS seismic data (2005) Geophysics, 70 (5), pp. U51-U65. , gpy GPYSA7 0016-8033 10.1190/1.2049350Gjøystdal, H., Reinhardsen, J.E., Ursin, B., Traveltime and wavefront curvature calculations in three-dimensional inhomogeneous layered media with curved interfaces (1984) Geophysics, 49, pp. 1466-1494. , gpy GPYSA7 0016-8033 10.1190/1.1441774Grechka, V., Tsvankin, I., NMO-velocity surfaces and Dix-type formulas in anisotropic heterogeneous media (2002) Geophysics, 67, pp. 939-951. , gpy GPYSA7 0016-8033 10.1190/1.1484536Grechka, V., Tsvankin, I., PP + PS = SS (2002) Geophysics, 67, pp. 1961-1971. , gpy GPYSA7 0016-8033 10.1190/1.1527096Grechka, V., Tsvankin, I., Bakulin, A., Signer, C., Hansen, J., Anisotropic inversion and imaging of PP and PS reflection data in the North Sea (2002) The Leading Edge, 21, pp. 90-97. , lee LEEDFF 1070-485X 10.1190/1.1445858Hubral, P., Computing true amplitude reflections in a laterally inhomogeneous earth (1983) Geophysics, 48, pp. 1051-1062. , gpy GPYSA7 0016-8033 10.1190/1.1441528Iversen, E., Amplitude, Fresnel zone, and NMO velocity for PP and SS normal-incidence reflections (2006) Geophysics, 71 (2), pp. W1-W14. , gpy GPYSA7 0016-8033 10.1190/1.2187814Iversen, E., Gjøystdal, H., Three-dimensional velocity inversion by use of kinematic and dynamic ray tracing (1984) 54th Annual International Meeting, pp. 643-645. , SEG, Expanded AbstractsLi, X.Y., Dai, H., Mancini, F., Converted-wave imaging in anisotropic media: Theory and case studies (2007) Geophysical Prospecting, 55, pp. 345-363. , 8uc GPPRAR 0016-8025 10.1111/j.1365-2478.2007.00612.xSchleicher, J., Tygel, M., Hubral, P., Parabolic and hyperbolic paraxial two-point traveltimes in 3D media (1993) Geophysical Prospecting, 41, pp. 495-513. , 8uc GPPRAR 0016-8025 10.1111/j.1365-2478.1993.tb00581.xStewart, R., Gaiser, J., Brown, R., Lawton, D., Converted-wave seismic exploration (2002) Methods: Geophysics, 67, pp. 1345-1363. , gpy GPYSA7 0016-8033 10.1190/1.1512781Stovas, A., Ursin, B., Second-order approximations of the reflection and transmission coefficients between two visco-elastic isotropic media (2001) Journal of Seismic Exploration, 9, pp. 223-233. , 9dy ZZZZZZ 0963-0651Stovas, A., Ursin, B., Reflection and transmission responses of layered transversely isotropic visco-elastic media (2003) Geophysical Prospecting, 51, pp. 447-477. , 8uc GPPRAR 0016-8025 10.1046/j.1365-2478.2003.00381.xTessmer, G., Behle, A., Common reflection point data stacking technique for converted waves (1988) Geophysical Prospecting, 36, pp. 671-678. , 8uc GPPRAR 0016-8025 10.1111/j.1365-2478.1988.tb02186.xThomsen, L., Weak elastic anisotropy (1986) Geophysics, 51, pp. 1954-1966. , gpy GPYSA7 0016-8033 10.1190/1.1442051Thomsen, L., Converted-wave reflection seismology over inhomogeneous, anisotropic media (1999) Geophysics, 63, pp. 678-690. , gpy GPYSA7 0016-8033 10.1190/1.1444577Tsvankin, I., Thomsen, L., Non-hyperbolic reflection moveout in anisotropic media (1994) Geophysics, 59, pp. 1290-1304. , gpy GPYSA7 0016-8033 10.1190/1.1443686Tygel, M., Ursin, B., Stovas, A., Convergence of traveltime power series for a layered VTI medium (2007) Geophysics, 72 (2), pp. D21-D28. , gpy GPYSA7 0016-8033 10.1190/1.2434774Ursin, B., Quadratic wavefront and traveltime approximations in inhomogeneous layered media with curved interfaces (1982) Geophysics, 47, pp. 1012-1021. , gpy GPYSA7 0016-8033 10.1190/1.1441365Ursin, B., Hokstad, K., Geometrical spreading in a layered transversely isotropic medium with vertical symmetry axis (2003) Geophysics, 68, pp. 2082-2091. , gpy GPYSA7 0016-8033 10.1190/1.1635062Xu, X., Tsvankin, I., Pech, A., Geometrical spreading of P-waves in horizontally layered, azimuthally anisotropic media (2005) Geophysics, 70 (5), pp. D43-D53. , gpy GPYSA7 0016-8033 10.1190/1.205246
Charisma and Spirituality in the Early Church: A Study of Messalianism and Pseudo-Macarius
No full textThe thesis is an investigation into the concept of Charisma and Spirituality in the Early Church with particular emphasis upon the writings of Ps-Macarius, and of a group of ascetics known as the Messalians, evident in the late fourth / early fifth centuries. The Macarian writings are
examined to see what they reveal about the experiential pneumatic theology of the Early Church, the relationship between Syrian and Hellenic traditions of Christian Rhetoric, and the relationship between Ps-Macarius and the Cappadocian Circle. The Macarian corpus as a whole is examined to assess its rhetorical influences and style. The rhetoric of the Macarian corpus is seen to illustrate a high degree of sophistication. This study also gives definition to two terms that have become imprecise and diverse in their use: 'enkrateia' (self-control), and
`Syrian Christianity'. By isolating the characteristics of enkratefa the definitive stages of an encratic lifestyle are identified. The breaking down of the term into enkrateia, radical enkrateta and exclusive enkrateta enables a much clearer discussion to take place as to the
nature of the encratic theology of a group or individual. The final element of this study is a consideration of the distinct Macarian imagery that is evident within the corpus. Two images are considered in detail, the 'flight of the soul' and 'sober intoxication'. Overall this study
shows the variety of influences upon Ps-Macarius, and the uniqueness of his expression. The influences upon Ps-Macarius include a context of endemic Syrian spirituality, a radical encratic lifestyle, a Hellenic rhetorical training, and a distinct interpretation of Platonic and Neo-
Platonic images, coupled to the wider Judaic / Mesopotamian influences of his Church. It is shown that Ps-Macarius represents an individual voice that is distinct and recognisable amongst the Fathers of the Church
Nuclear translocation and signalling of L1-CAM in human carcinoma cells requires ADAM10 and presenilin/gamma-secretase activity
No full textL1-CAM (L1 cell-adhesion molecule), or more simply L1, plays an important role in the progression of human carcinoma. Overexpression promotes tumour-cell invasion and motility, growth in nude mice and tumour metastasis. It is feasible that L1-dependent signalling contributes to these effects. However, little is known about its mechanism in tumour cells. We reported previously that L1 is cleaved by ADAM (a disintegrin and metalloprotease) and that the cytoplasmic part is essential for L1 function. Here we analysed more closely the role of proteolytic cleavage in L1-mediated nuclear signalling. Using OVMz carcinoma cells and L1-transfected cells as a model, we found that ADAM10-mediated cleavage of L1 proceeds in lipid raft and non-raft domains. The cleavage product, L1-32, is further processed by PS (presenilin)/gamma-secretase to release L1-ICD, an L1 intracellular domain of 28 kDa. Overexpression of dominantnegative PS1 or use of a specific gamma-secretase inhibitor leads to an accumulation of L1-32. Fluorescence and biochemical analysis revealed a nuclear localization for L1-ICD. Moreover, inhibition of ADAM10 and/or gamma-secretase blocks nuclear translocation of L1-ICD and L1-dependent gene regulation. Overexpression of recombinant L1-ICD mediates gene regulation in a similar manner to full-length L1. Our results establish for the first time that regulated proteolytic processing by ADAM10 and PS/gamma-secretase is essential for the nuclear signalling of L1 in human carcinoma cell lines. Key words: a disintegrin and metalloprotease 10 (ADAM10), L1 cell-adhesion molecule (L1-CAM), nuclear translocation, presenilin (PS)/gamma-secretase activity, raft, signalling
LinoSPAD2: A 512×1 linear SPAD camera with system-level 135-ps SPTR and a reconfigurable computational engine for time-resolved single-photon imaging
No full textThe LinoSPAD2 camera combines a 512×1 linear single-photon avalanche diode (SPAD) array with an FPGA-based photon-counting and time-stamping platform, to create a reconfigurable sensing system capable of detecting single photons. The read-out is fully parallel, where each SPAD is connected to a different FPGA input. The hardware can be reconfigured to achieve different functionalities, such as photon counters, time-to-digital converter (TDC) arrays and histogramming units. Time stamping is performed by an array of 64 TDCs, with 20 ps resolution (LSB), serving 256 channels by means of 4:1 sharing. At sensor level, the pixel pitch is 26.2 μm with a fill factor of 25.1%. The median dark count rate of each SPAD at room temperature is below 100 cps at 6V excess bias, the single-photon timing resolution (SPTR) of each channel is 50 ps FWHM, and the peak photon detection probability reaches ~50% at 510 nm at the same excess bias. The fill factor can be increased by 2.3× by means of microlenses, with good spatial uniformity and flat spectral response above 400 nm. At system level, the average instrument response function (IRF) is 135 ps FWHM. The LinoSPAD2 camera enables a wide range of time-of-flight and time-resolved applications, including 3D imaging, fluorescence lifetime imaging microscopy (FLIM), heralded spectroscopy, and compressive Raman imaging, to name a few. Thanks to its features, LinoSPAD2 is a novel generation of reconfigurable single-photon image sensors capable of adapting their read-out and processing to match application-specific requirements, and combining SPAD arrays with advanced, massively-parallel computational functionalities. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.QCD/DiCarlo La
Autumn equinox celebration
No full textFotodokumentasjon. Fotograf: Christa HolkaPS/Y’s Hysteria programme and LUX hosts an outdoor celebration of autumn equinox led by Danish artist Marie Kølbæk Iversen and accompanied by Diana Policarpo. The evening will be centred around the performance of magical songs inherited by the artist from her great-great-great-great-grandparents, who in 1873 were the ethnographic subjects of folklore collector Evald Tang Christensen. The songs relate to the Southern Scandinavian shamanist culture Sejd and springs from a very different cultural source than the Protestant Christianity time of their collection: They are largely (and in places explicitly) feminist, apocalyptic, anti-Christian, anti-nationalist and anti-Danish. In the Northern hemisphere autumn equinox marks the threshold into winter darkness – and symbolically into the dreams of an extended night. It therefore celebrates the power of dreaming to unsettle the fabric of reality by rendering weird—Wyrd—and contingent, the waking life of our troubled modernity. Marie Kølbæk Iversen’s Autumn equinox celebration is part of PS/Y’s Hysteria – a combined arts programme that explores health and illness in contemporary society, focusing on issues of gender, race and cultural identity. Hysteria is curated by Mette Kjærgaard Præst and takes place in partnership with organisations and institutions across London from August 2017 until April 2018
Synthesis and Characterization of PEO-PS-PEO Triblock Copolymer Conjugated with Ni-NTA for Biosensors, 2018
No full textPoly(ethylene oxide)-poly(styrene)-poly(ethylene oxide) triblock copolymer with di-hydroxyl terminated groups (HO-PEO-PS-PEO-OH) was conjugated with nitrilotriacetic acid (NTA) via esterification reaction using N,N'-Dicyclohexylcarbodiimide (DCC), 4-Dimethylaminopyridine (DMAP) and Dimethylformamide (DMF) as a solvent at 80 ?C. The poly(ethylene oxide)-poly(styrene)-poly(ethylene oxide) with NTA end groups (NTA-PEO-PS-PEO-NTA) was characterized and structure confirmed by 1H NMR, 13C NMR, and FT-IR spectroscopies. Thermogravimetric analysis (TGA) was carried out to investigate the thermal stability of the starting triblock copolymer poly(ethylene oxide)-poly(styrene)-poly(ethylene oxide) with di-hydroxyl terminated groups (HO-PEO-PS-PEO-OH) and the conjugated poly(ethylene oxide)-poly(styrene)-poly(ethylene oxide) functional polymer (NTA-PEO-PS-PEO-NTA). Surface morphologies of the (HO-PEO-PS-PEO-OH) and (NTA-PEO-PS-PEO-NTA) were studied by atomic force microscopy. In addition, the size distributions were determined using dynamic light scattering. The thermal behavior of the (HO-PEO-PS-PEO-OH) and (NTA-PEO-PS-PEO-NTA) were examined by differential scanning calorimetry (DSC). DSC thermograms indicate the formation of a two phase polymer matrix. The poly(ethylene oxide)-poly(styrene)-poly(ethylene oxide) with NTA functionalized end groups (NTA-PEO-PS-PEO-NTA) was bound or chelated with Ni(II) metal ion. The binding studies were carried out by ultraviolet-visible (UV-Vis) spectroscopy. The electronic behaviors of PEO-b-PS-b-PEO/ PS/ NTA-PEO-b-PS-b-PEO-NTA with ratio (1/5/1) and PEO-b-PS-b-PEO/ PS/ NTA-PEO-b-PS-b-PEO-NTA-Ni containing 1% of oxidized single-walled carbon nanotubes (SWCNTs) were investigated by IV plots from Kelvin sensing. The IV plots before sensitizing with protein varied from the IV plots after binding with protein indicating that the composites may be used as active components in biosensors. KEYWORDS: Materials Chemistry, Polymer Chemistr
The contribution shift of ammonia-oxidizing archaea and bacteria to ammoxidation under Ag-NPs/SWCNTs/PS-NPs stressors in constructed wetlands
No full textAmmonia-oxidizing microorganisms (AOMs, archaea (AOA) and bacteria (AOB)) are primarily responsible for the ammoxidation in constructed wetlands (CWs). However, little is known about evaluating the response of AOA and AOB to engineered nanomaterials (ENMs) and quantifying the shift of their contribution to ammoxidation. Herein, we operated a series of CWs exposing to silver nanoparticles (Ag-NPs), single-walled carbon nanotubes (SWCNTs), and polystyrene nano-sized plastics (PS-NPs) with the wastewater-accumulating concentration of ENMs for 180 days. The results showed that the abundance of AOA amoA gene in situ was far lower than that of AOB, while the abundance ratio of AOA to AOB increased by 15 folds after 180-day experiment. Using DNA stable isotope probing (DNA-SIP) experiment, we found that the active AOB microbiota varied substantially but the AOA was more stable across different groups. Furthermore, the co-occurrence analysis proved that ENMs stress increased the negative coexistence pattern of AOA and AOB; predictive functional profiling showed that the ENMs enhanced the functional advantage of AOA by inhibiting AOB (mainly hydroxylamine oxidation process). Finally, the contribution of AOA increased under exposing to SWCNTs (18.35%), PS-NPs (24.92%), and Ag-NPs (32.14%) compared with control group (0.03%) for 180 days. Despite this, AOB was still the primary executant of ammoxidation in CWs. Overall, in our study, the differences in activities and contributions of AOMs were quantified in CWs, and a significantly negative coexistence relationship between AOA and AOB was revealed when exposed to emerging nanomaterials.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Sanitary Engineerin
Dionysios Ps.-Areiopagites im heutigen Forschungsgespräch
No full textThe intention of this paper is to overcome an alarming polarization within the actual academic debate on the writing of the unknown author of the Corpus Areopagiticum. It discusses five exemplary problems: a. unity and diversity in God; b. theurgy in Proklos and Ps.-Dionysios; c. Porphyry, Dionysios and the “anthropological Model” for the solution of the Christological problem; d. ambivalences within the Dionysian corpus; e. the intention of the author. In the introduction the paper also touches – very briefly, it is true – upon the question, if Peter the Iberian could have been the author of that corpus, as – independently from each other – E. Honigmann and S. Nutsubidze once proposed
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