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Displaying Results 1426 - 1450 of 1489 on page 58 of 60
Marked
Mark
Exceptional Vertex Operator Algebras and the Virasoro Algebra
(2008)
Tuite, Michael P.
Exceptional Vertex Operator Algebras and the Virasoro Algebra
(2008)
Tuite, Michael P.
Abstract:
We consider exceptional vertex operator algebras for which particular Casimir vectors constructed from the primary vectors of lowest conformal weight are Virasoro descendants of the vacuum. We discuss constraints on these theories that follow from an analysis of appropriate genus zero and genus one two point correlation functions. We find explicit differential equations for the partition function in the cases where the lowest weight primary vectors form a Lie algebra or a Griess algebra. Examples include the Wess-Zumino-Witten model for Deligne's exceptional Lie algebras and the Moonshine Module. We partially verify the irreducible decomposition of the tensor product of Deligne's exceptional Lie algebras and consider the possibility of similar decompositions for tensor products of the Griess algebra. We briefly discuss some conjectured extremal vertex operator algebras arising in Witten's recent work on three dimensional black holes.
http://hdl.handle.net/10379/2446
Marked
Mark
The Genus Two Partition Function for Free Bosonic and Lattice Vertex Operator Algebras
(2007)
Mason, Geoffrey; Tuite, Michael P.
The Genus Two Partition Function for Free Bosonic and Lattice Vertex Operator Algebras
(2007)
Mason, Geoffrey; Tuite, Michael P.
Abstract:
We define the $n$-point function for a vertex operator algebra on a genus two Riemann surface in two separate sewing schemes where either two tori are sewn together or a handle is sewn to one torus. We explicitly obtain closed formulas for the genus two partition function for the Heisenberg free bosonic string and lattice vertex operator algebras in both sewing schemes. We prove that the partition functions are holomorphic in the sewing parameters on given suitable domains and describe their modular properties. Finally, we show that the partition functions cannot be equal in the neighborhood of a two-tori degeneration point where they can be explicitly compared.
http://hdl.handle.net/10379/2447
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Mark
Torus n-Point Functions for $\mathbb{R}$-graded Vertex Operator Superalgebras and Continuous Fermion Orbifolds
(2007)
Mason, Geoffrey; Tuite, Michael P.; Zuevsky, Alexander
Torus n-Point Functions for $\mathbb{R}$-graded Vertex Operator Superalgebras and Continuous Fermion Orbifolds
(2007)
Mason, Geoffrey; Tuite, Michael P.; Zuevsky, Alexander
Abstract:
We consider genus one n-point functions for a vertex operator superalgebra with a real grading. We compute all n-point functions for rank one and rank two fermion vertex operator superalgebras. In the rank two fermion case, we obtain all orbifold n-point functions for a twisted module associated with a continuous automorphism generated by a Heisenberg bosonic state. The modular properties of these orbifold n-point functions are given and we describe a generalization of Fay's trisecant identity for elliptic functions.
http://hdl.handle.net/10379/2448
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Mark
On Genus Two Riemann Surfaces Formed from Sewn Tori
(2006)
Mason, Geoffrey; Tuite, Michael P.
On Genus Two Riemann Surfaces Formed from Sewn Tori
(2006)
Mason, Geoffrey; Tuite, Michael P.
Abstract:
We describe the period matrix and other data on a higher genus Riemann surface in terms of data coming from lower genus surfaces via an explicit sewing procedure. We consider in detail the construction of a genus two Riemann surface by either sewing two punctured tori together or by sewing a twice-punctured torus to itself. In each case the genus two period matrix is explicitly described as a holomorphic map from a suitable domain (parameterized by genus one moduli and sewing parameters) to the Siegel upper half plane $\mathbb{H}_{2}$. Equivariance of these maps under certain subgroups of $Sp(4,\mathbb{Z)}$ is shown. The invertibility of both maps in a particular domain of $\mathbb{H}_{2}$ is also shown.
http://hdl.handle.net/10379/2450
Marked
Mark
Torus Chiral n-Point Functions for Free Boson and Lattice Vertex Operator Algebras
(2002)
Mason, Geoffrey; Tuite, Michael P.
Torus Chiral n-Point Functions for Free Boson and Lattice Vertex Operator Algebras
(2002)
Mason, Geoffrey; Tuite, Michael P.
Abstract:
We obtain explicit expressions for all genus one chiral n-point functions for free bosonic and lattice vertex operator algebras. We also consider the elliptic properties of these functions.
http://hdl.handle.net/10379/2451
Marked
Mark
Some Irrational Generalised Moonshine from Orbifolds
(2002)
Ivanov, Rossen I.; Tuite, Michael P.
Some Irrational Generalised Moonshine from Orbifolds
(2002)
Ivanov, Rossen I.; Tuite, Michael P.
Abstract:
We verify the Generalised Moonshine conjectures for some irrational modular functions for the Monster centralisers related to the Harada-Norton, Held, $M_{12}$ and $L_3(3)$ simple groups based on certain orbifolding constraints. We find explicitly the fixing groups of the hauptmoduls arising in each case.
http://hdl.handle.net/10379/2452
Marked
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Rational Generalised Moonshine from Abelian Orbifoldings of the Moonshine Module
(2001)
Ivanov, Rossen I.; Tuite, Michael P.
Rational Generalised Moonshine from Abelian Orbifoldings of the Moonshine Module
(2001)
Ivanov, Rossen I.; Tuite, Michael P.
Abstract:
We consider orbifoldings of the Moonshine Module with respect to the abelian group generated by a pair of commuting Monster group elements with one of prime order $p=2,3,5,7$ and the other of order $pk$ for $k=1$ or $k$ prime. We show that constraints arising from meromorphic orbifold conformal field theory allow us to demonstrate that each orbifold partition function with rational coefficients is either constant or is a hauptmodul for an explicitly found modular fixing group of genus zero. We thus confirm in the cases considered the Generalised Moonshine conjectures for all rational modular functions for the Monster centralisers related to the Baby Monster, Fischer, Harada-Norton and Held sporadic simple groups. We also derive non-trivial constraints on the possible Monster conjugacy classes to which the elements of the orbifolding abelian group may belong.
http://hdl.handle.net/10379/2453
Marked
Mark
Genus Two Meromorphic Conformal Field Theory
(1999)
Tuite, Michael P.
Genus Two Meromorphic Conformal Field Theory
(1999)
Tuite, Michael P.
Abstract:
We construct the genus two (or two loop) partition function for meromorphic bosonic conformal field theories. We use a sewing procedure involving two genus one tori by exploiting an explicit relationship between the genus two period matrix and pinching modular parameters. We obtain expressions for the partition function for the chiral bosonic string, even rank lattice theories and self-dual meromorphic conformal field theories including the Moonshine Module. In particular, we find that for self-dual theories with central charge 24, the genus two partition function multiplied by a universal holomorphic function of the moduli is given by a meromorphic Siegel modular form of weight 2 where this universal function includes ghost contributions. We also discuss a novel expansion for certain Siegel modular forms.
http://hdl.handle.net/10379/2454
Marked
Mark
Synthesis, electrical and magnetotransport properties of polypyrrole-MWCNT nanocomposite
(2011)
BLAU, WERNER
Synthesis, electrical and magnetotransport properties of polypyrrole-MWCNT nanocomposite
(2011)
BLAU, WERNER
Abstract:
The present work describes the preparation of nanocomposites in which the multiwall carbon nanotubes (MWCNT) have been mixed with conducting polypyrrole (PPy) via an in situ chemical oxidative preparation method. To reveal their structural, morphological and thermal properties, the composites have been characterized by X-ray diffraction, field emission scanning electron microscope, Fourier transform infrared, thermogravimetric analysis respectively. Electrical transport and magnetotransport properties have been investigated in the temperature range 77–300 K in presence as well as in absence of magnetic field up to 1Tesla. The conductivities of the composites are greater than that of pure polypyrrole. All the investigated samples follow Mott’s variable range hopping (VRH) theory whereas the magnetic field dependent conductivity have been explained in terms of two opposite but simultaneously acting hopping effect-wave function shrinkage and forward interference effect.
http://hdl.handle.net/2262/61639
Marked
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Study of the mechanical, electrical and morphological properties of PU/ MWCNT composites obtained by two different processing routes
(2012)
KHAN, UMAR; COLEMAN, JONATHAN NESBIT
Study of the mechanical, electrical and morphological properties of PU/ MWCNT composites obtained by two different processing routes
(2012)
KHAN, UMAR; COLEMAN, JONATHAN NESBIT
Abstract:
A comparative study of the influence of processing route on polyurethanes (PU)/ Multiwalled carbon nanotube (MWCNT) composites mechanical and electrical properties and also morphology was undergone employing two differentiated processing methods, solvent casting and buckypaper infiltration, for producing PU composites with low, medium and high mass fractions of acid treated MWCNT, and with no covalent linkages between the matrix and the nanotubes. As for example, with a MWCNT mass fraction of ∼ 18 wt% the second method produced stiffer (270 MPa), lighter (948 kg m-3) and more electrically conductive (1.8 S cm-1) composite while the first one gave softer (111 MPa) and more ductile (141%) materials. These properties differences are related to the different PU/MWCNT dispositions obtained through each synthesis route. Nanotubes percolating concentration is found to be crucial on composite properties evolution and a preferential interaction of MWCNT with PU hard segments is observed for ...
http://hdl.handle.net/2262/61668
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Mark
Antiferroelectric and ferroelectric orderings in frustrated chiral tilted smectics and a continuous change from anticlinic SmCA* to synclinic SmC*
(2010)
VIJ, JAGDISH KUMAR
Antiferroelectric and ferroelectric orderings in frustrated chiral tilted smectics and a continuous change from anticlinic SmCA* to synclinic SmC*
(2010)
VIJ, JAGDISH KUMAR
Abstract:
In a frustrated binary-mixture system of ferroelectric and antiferroelectric liquid crystals, where the border line between SmCA* and SmC* in the temperature-concentration phase diagram runs almost parallel to the ordinate temperature axis, we have found a continuous change between them close to the critical concentration. The continuity has been confirmed as an intrinsic property in the bulk by observing almost perfect bell-shaped Bragg reflection bands due to the helicoidal director structure. The temperature variation of peak wavelength of the half-pitch band and, in particular, the characteristic disappearance of the full-pitch band apparently within the SmC* temperature region have been simulated with a change in the ratio of ferroelectric and antiferroelectric orderings. The observed continuous change has been described by the entropy effect in the 1D Ising model with the synclinic and anticlinic orderings as spins.
http://hdl.handle.net/2262/61732
Marked
Mark
Macroscopic biaxiality and electric-field induced rotation of the minor director in the nematic phase of a bent-core liquid crystal
(2010)
VIJ, JAGDISH KUMAR; NAGARAJ, MAMATHA
Macroscopic biaxiality and electric-field induced rotation of the minor director in the nematic phase of a bent-core liquid crystal
(2010)
VIJ, JAGDISH KUMAR; NAGARAJ, MAMATHA
Abstract:
Biaxiality in the nematic phase has been investigated for the bent-core liquid-crystal para-heptylbenzoate diester, using polarised IR spectroscopy. Anisotropic fluctuations of the nematic director are discussed in terms of the self-assembly of the chiral conformers. The ordering of the minor director for the homeotropicaly aligned sample is found to depend on the rubbing of the substrates of the cell and the amplitude of in-plane electric field. On increasing the in-plane electric field, the rotation of the minor director in the plane of the substrate is observed with an angle of approximately 45°, where initially the minor director is shown to lie along the rubbing direction. It is also shown that on the average the long axis of the molecules is normal to the substrate with surface treatment, with and without rubbing. The electric in-plane field combined with rubbing is shown to induce biaxial order in the nematic phase of a material with negative dielectic anisotropy for the firs...
http://hdl.handle.net/2262/61733
Marked
Mark
Modeling the photochemical effects present during holographic grating formation in photopolymer materials
(2007)
Gleeson, M. R.; Kelly, John V.; Sabol, Dušan; Close, Ciara E.; Liu, Shui; Sheridan, Joh...
Modeling the photochemical effects present during holographic grating formation in photopolymer materials
(2007)
Gleeson, M. R.; Kelly, John V.; Sabol, Dušan; Close, Ciara E.; Liu, Shui; Sheridan, John T.
Abstract:
The development of a theoretical model of the processes present during the formation of a holographic grating in photopolymer materials is crucial in enabling further development of holographic applications. To achieve this, it is necessary to understand the photochemical and photophysical processes involved and to isolate their effects, enabling each to be modeled accurately. While photopolymer materials are practical materials for use as holographic recording media, understanding the recording mechanisms will allow their limitations for certain processes to be overcome. In this paper we report generalizations of the nonlocal polymer driven diffusion (NPDD) model to include the effects of photosensitive dye absorption and the inhibition effects.
http://hdl.handle.net/10197/3440
Marked
Mark
Ruserford Back-scattering and Micro-Raman spectroscopy of composite a-C:Pt films grown by magnetron co-sputtering of graphite and Pt targets by photoelectrochemical etching of silicon
(2010)
PEROVA, TATIANA
Ruserford Back-scattering and Micro-Raman spectroscopy of composite a-C:Pt films grown by magnetron co-sputtering of graphite and Pt targets by photoelectrochemical etching of silicon
(2010)
PEROVA, TATIANA
Abstract:
Raman spectra have been measured in the spectral range from 1000 to 1800 cm−1 on samples of amorphous carbon modified with platinum in amounts comparable with that of carbon. Also, Rutherford backscattering spectra have been studied. It is shown that, as the platinum concentration is raised to ∼0.5 × 1022 at cm−3, the average size of graphene clusters increases. As the platinum concentration increases further, the graphene clusters become smaller in size.
http://hdl.handle.net/2262/61764
Marked
Mark
Optical properties of grooved silicon structures: theory and experiment
(2011)
PEROVA, TATIANA
Optical properties of grooved silicon structures: theory and experiment
(2011)
PEROVA, TATIANA
Abstract:
The reflection spectra of grooved silicon structures consisting of alternating silicon walls and grooves (air channels) with a period of a = 4–6 μm are studied experimentally and theoretically in the mid-IR spectral range (2–25 μm) upon irradiation of samples by normally incident light polarized along and perpendicular to silicon layers. The calculation is performed by the scattering matrix method taking into account Rayleigh scattering losses in a grooved layer by adding imaginary parts to the refractive indices of silicon and air in grooved regions. The experimental and calculated reflection spectra are in good agreement in the entire spectral range studied. The analysis of experimental and calculated spectra gave close values of the effective refractive indices and birefringence of the studied structures in the long-wavelength spectral region. The values calculated in the effective medium model in the long-wavelength approximation (λ ≫ a) gave considerably understated values. The...
http://hdl.handle.net/2262/61773
Marked
Mark
Search for Pulsed TeV Gamma-ray Emission from the Crab Pulsar
(1999)
Lang, Mark; Gillanders, Gary; Lessard, R. W.; Bond, I. H.; Bradbury, S. M.; Buckley, J....
Search for Pulsed TeV Gamma-ray Emission from the Crab Pulsar
(1999)
Lang, Mark; Gillanders, Gary; Lessard, R. W.; Bond, I. H.; Bradbury, S. M.; Buckley, J. H.; Burdett, A. M.; Carter-Lewis, D. A.; Catanese, M.; Cawley, M. F.; D'Vali, M.; Fegan, D. J.; Finley, J. P.; Gaidos, J. A.; Gillanders, G. H.; Hall, T.; Hillas, A. M.; Krennrich, F.; Lang, M. J.; Masterson, C.
Abstract:
We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10 m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 November and 1997 March. During this period the Whipple 10 m telescope was operated at its lowest energy threshold to date. Spectral analysis techniques were applied to search for the presence of a gamma-ray signal from the Crab pulsar over the energy band 250 GeV to 4 TeV. We do not see any evidence of the 33 ms pulsations present in other energy bands from the Crab pulsar. The 99.9% confidence level upper limit for pulsed emission above 250 GeV is derived to be 4.8x10^-12 cm^-2 s^-1 or <3% of the steady flux from the Crab Nebula. These results imply a sharp cut-off of the power-law spectrum seen by the EGRET instrument on the Compton Gamma-Ray Observatory. If the cut-off is exponential, it must begin at 60 GeV or lower to accommodate these upper limits.
http://hdl.handle.net/10379/2489
Marked
Mark
Investigation of germanium implanted with hydrogen for layer transfer applications
(2011)
PEROVA, TATIANA
Investigation of germanium implanted with hydrogen for layer transfer applications
(2011)
PEROVA, TATIANA
Abstract:
The technology for thin Ge layer transfer by hydrogen ion-cut process is characterised in this work. Experiments were carried out to determine suitable hydrogen ion implantation doses in germanium for the low temperature ion cut process by examining the formation of blisters on implanted samples. Raman and Spreading Resistance Profiling (SRP) have been used to analyse defects in germanium caused by hydrogen implants. Bevelling has been used to facilitate probing beyond the laser penetration depth. Results of Raman mapping along the projection area reveal that after post implant annealing at 400 oC, some crystal damage remains, while at 600 oC, the crystal damage has been repaired. SRP shows that some amount of hydrogen acceptor states (~1Î1016 acceptors/cm2) remain after 600 oC. These are thought to be vacancy-related point defect clusters.
http://hdl.handle.net/2262/61803
Marked
Mark
Identifying and Localizing Intracellular Nanoparticles Using Raman Spectroscopy
(2012)
Dorney, Jennifer; Bonnier, Franck; Garcia, Amaya; Casey, Alan; Chambers, Gordon; Byrne,...
Identifying and Localizing Intracellular Nanoparticles Using Raman Spectroscopy
(2012)
Dorney, Jennifer; Bonnier, Franck; Garcia, Amaya; Casey, Alan; Chambers, Gordon; Byrne, Hugh
Abstract:
<p>Raman microscopy is employed to spectroscopically image biological cells previously exposed to fluorescently labelled polystyrene nanoparticles and, in combination with K-means clustering and Principal Component Analysis (PCA), is demonstrated to be capable of localising the nanoparticles and identifying the subcellular environment based on the molecular spectroscopic signatures. The neutral nanoparticles of 50 nm or 100 nm, as characterised by dynamic light scattering, are shown to be non-toxic to a human lung adenocarcinoma cell-line (A549), according to a range of cytotoxicity assays including Neutral Red, Alamar Blue, Coomassie Blue and (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Confocal fluorescence microscopy identifies intracellular fluorescence due to the nanoparticle exposure, but the fluorescence distribution is spatially diffuse, potentially due to detachment of the dye from the nanoparticles, and the technique fails to unambiguously ide...
http://arrow.dit.ie/radart/35
Marked
Mark
Compressibility of rotating black holes
(2011)
Dolan, Brian P.
Compressibility of rotating black holes
(2011)
Dolan, Brian P.
Abstract:
Interpreting the cosmological constant as a pressure, whose thermodynamically conjugate variable is a volume, modifies the first law of black hole thermodynamics. Properties of the resulting thermodynamic volume are investigated: the compressibility and the speed of sound of the black hole are derived in the case of non-positive cosmological constant. The adiabatic compressibility vanishes for a non-rotating black hole and is maximal in the extremal case — comparable with, but still less than, that of a cold neutron star. A speed of sound vs is associated with the adiabatic compressibility, which is is equal to c for a non-rotating black hole and decreases as the angular momentum is increased. An extremal black hole has v2 s = 0.9 c2 when the cosmological constant vanishes, and more generally vs is bounded below by c/√2.
http://eprints.nuim.ie/3031/
Marked
Mark
Quantum transport of Au-S-S-Au nanoscale junctions
(2012)
SANVITO, STEFANO
Quantum transport of Au-S-S-Au nanoscale junctions
(2012)
SANVITO, STEFANO
Abstract:
Transport in S2 molecules sandwiched between Au electrodes is investigated with a combination of density functional theory and the non-equilibrium Green’s function method. We consider four different configurations and find that their conductances are related to the details of the bonding geometry. When S2 connects to pyramidal-shaped electrodes at the top site, the transmission is governed by a resonance and is strongly affected by the bias. In contrast, the transport of the remaining three configurations is through several closely spaced broad molecular orbitals, and the transmission coefficient is almost flat around the Fermi level.
http://hdl.handle.net/2262/61993
Marked
Mark
Mechanisms for thermal conduction in hydrogen hydrate
(2012)
English, Niall J.; Gorman, Paul D.; MacElroy, J. M. Don
Mechanisms for thermal conduction in hydrogen hydrate
(2012)
English, Niall J.; Gorman, Paul D.; MacElroy, J. M. Don
Abstract:
Extensive equilibrium molecular dynamics (MD) simulations have been performed to investigate thermal conduction mechanisms via the Green-Kubo approach for (type II) hydrogen hydrate, at 0.05 kbar and between 30 and 250 K, for both lightly-filled H2 hydrates (1s4l) and for more densely-filled H2 systems (2s4l), in which four H2 molecules are present in the large cavities, with respective single- and double-occupation of the small cages. The TIP4P water model was used in conjunction with a fully atomistic hydrogen potential along with long-range Ewald electrostatics. It was found that substantially less damping in guest-host energy transfer is present in hydrogen hydrate as is observed in common type I clathrates (e.g., methane hydrate), but more akin in to previous results for type II and H methane hydrate polymorphs. This gives rise to larger thermal conductivities relative to common type I hydrates, and also larger than type II and H methane hydrate polymorphs, and a more crystal-l...
http://hdl.handle.net/10197/3495
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Mark
Fluorescence Emission Study of Cdse/ZnS Quantum Dot and Au Nanoparticles Composite for Application in Quantum Dot Solar Concentrators
(2011)
Chandra, Subhash; Doran, J; Kennedy, Manus; McCormack, S; Chatten, A
Fluorescence Emission Study of Cdse/ZnS Quantum Dot and Au Nanoparticles Composite for Application in Quantum Dot Solar Concentrators
(2011)
Chandra, Subhash; Doran, J; Kennedy, Manus; McCormack, S; Chatten, A
Abstract:
<p>Fluorescence of core shell (CdSe/ZnS) quantum dots (QDs) and Au nanoparticles (NPs) composite has been studied for application in quantum dot solar concentrators (QDSC). We conclude two points from the particular QD/Au NP composite studied. One; for the particular Au NPs concentration, the relative fluorescence emission enhancement increases with decreasing QD concentration. Second; the enhancement is more pronounced for the Au nanoparticles whose surface plasmon resonance wavelength overlaps with the absorption peak of QDs. The fundamental concept that could describe the change in fluorescence emission of QDs in the presence of Au NPs is the locally enhanced electromagnetic field induced by the surface plasmon resonance in the Au NPs. This leads to change in absorption, excitation and emission rate for the QDs. The optimal concentration depends on the coupling and spacing between neighbouring QDs and Au NPs.</p>
http://arrow.dit.ie/dubencon2/67
Marked
Mark
Enhanced Quantum Dot Emission for Luminescent Solar Concentrators Using Plasmonic Interaction
(2011)
Chandra, Subhash; Kennedy, Manus; Doran, John; McCormack, Sarah; Chatten, A. J.
Enhanced Quantum Dot Emission for Luminescent Solar Concentrators Using Plasmonic Interaction
(2011)
Chandra, Subhash; Kennedy, Manus; Doran, John; McCormack, Sarah; Chatten, A. J.
Abstract:
<p>Plasmonic excitation enhanced fluorescence of CdSe/ZnS core-shell quantum dots (QDs) in the presence of Au nanoparticles (NPs) has been studied for application in quantum dot solar concentrator (QDSC) devices. We observe that there is an optimal concentration of Au NPs that gives a maximum 53% fluorescence emission enhancement for the particular QD/Au NP composite studied. The optimal concentration depends on the coupling and spacing between neighboring QDs and Au NPs. We show the continuous transition from fluorescence enhancement to quenching, depending on Au NP concentration. The locally enhanced electromagnetic field induced by the surface plasmon resonance in the Au NPs leads to an increased excitation rate for the QDs. This is evidenced by excitation wavelength dependent fluorescence enhancement, where the locally enhanced field around the Au NPs is more pronounced close to the surface plasmon resonance (SPR) wavelength. However, at higher concentrations of Au NPs non...
http://arrow.dit.ie/dubenart/49
Marked
Mark
Assessment of an Osteoblast-like Cell Line as a Model for Human Primary Osteoblasts Using Raman Spectroscopy
(2012)
McManus, Lindsay; Bonnier, Franck, Dr; Burke, George; Meenan, Brian; Boyd, Adrian; Byrn...
Assessment of an Osteoblast-like Cell Line as a Model for Human Primary Osteoblasts Using Raman Spectroscopy
(2012)
McManus, Lindsay; Bonnier, Franck, Dr; Burke, George; Meenan, Brian; Boyd, Adrian; Byrne, Hugh James, Prof
Abstract:
<p>Raman spectroscopy is employed to determine the suitability of the U20S osteoblast-like cell line for use as a model for human primary osteoblasts, with emphasis on the ability of these cell types to replicate their tissue of origin. It was found that both cell types demonstrated early stage mineral deposition that followed significantly different growth patterns. Analysis of the growth pattern and spectral data from primary cells revealed increasing bone quality ratios and a high crystallinity, consistent with previous reports. Conversely the investigation of the U20S osteoblast-like cell line provided evidence of dense multilayered mineralised regions that corresponded more closely to native bone in terms of its crystallinity and bone quality ratios. This finding contradicts previous reports on U20S osteoblast-like cells which have consistently described them as non-osteoinductive when cultured in various conditions on a number of substrates. This work demonstrates t...
http://arrow.dit.ie/biophonart/1
Marked
Mark
The Clinical Utility of Forced Vital Capacity Measured at Six Seconds in the Spirometric Detection of Airways Obstruction
(2007)
Kelly, Janine, (Thesis)
The Clinical Utility of Forced Vital Capacity Measured at Six Seconds in the Spirometric Detection of Airways Obstruction
(2007)
Kelly, Janine, (Thesis)
http://arrow.dit.ie/scienmas/73
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