<p>This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for white light. Obtaining such fringes in a Michelson interferometer is not a trivial task.1 The interferometer is typically illuminated with a monochromatic source and the path length difference adjusted with a wedge angle between the interferometer mirrors so that five or six vertical fringes are visible, indicating nearly equal paths. Then the mirrors are adjusted until the fringes are almost perfectly straight. Finally we use a white light source and carefully scan through the approximately equal path range until five or six white light fringes are seen to sweep rapidly by.</p>

Abstract: This paper presents an experimental investigation of two different magnetorheological ( MR) fluids, namely, water-based and hydrocarbon-based MR fluids in compression mode under various applied currents. Finite element method magnetics was used to predict the magnetic field distribution inside the MR fluids generated by a coil. A test rig was constructed where the MR fluid was sandwiched between two flat surfaces. During the compression, the upper surface was moved towards the lower surface in a vertical direction. Stress-strain relationships were obtained for arrangements of equipment where each type of fluid was involved, using compression test equipment. The apparent compressive stress was found to be increased with the increase in magnetic field strength. In addition, the apparent compressive stress of the water-based MR fluid showed a response to the compressive strain of greater magnitude. However, during the compression process, the hydrocarbon-based MR fluid appear...

Despite tremendous advances by women in the natural and applied sciences, where in selective fields women have surpassed men in the earning of doctoral degrees for more nearly 20 years, female enrollment levels in engineering continue to be a fraction of male enrollment. Gender disparities of more than 60% persist in undergraduate engineering enrollments and have recently worsened. As American female Civil Engineering enrollment has been flat for over 25 years, efforts must be taken to understand this stasis. This paper focuses primarily on secondary education preparation in terms of both attitudes towards and enrollment levels in pre-engineering courses such as calculus, chemistry, and physics. Additional consideration is given to enrollment and achievement in advanced placement courses, as reflected in national examination rates. This paper concludes that secondary school participation and achievement in physics courses is a critical differential factor as one explanatory ele...

<p>We establish geometric properties of Stiefel and Grassmann manifolds which arise in relation to Slatertype variational spaces in many-particle Hartree-Fock theory and beyond. In particular, we prove thatthey are analytic homogeneous spaces and submanifolds of the space of bounded operators on the single-particle Hilbert space. As a by-product we obtain that they are complete Finsler manifolds. These geometric properties underpin state-of-the-art results on existence of solutions to Hartree-Fock type equations.</p>

Negative ion research is stimulated by the need for high power and high density neutral beams for neutral beam heating systems to be used in proposed nuclear fusion reactors. Extensive research has been carried out on the enhancement of the production of negative ions from hydrogen/deuterium discharges. The negative ion sources used at present are being investigated in order to optimise current densities of H7D' for future fusion machines.
In this thesis low pressure radio frequency (RF) hydrogen plasmas are investigated and compared to filament driven hydrogen plasmas to understand further the physics in the two different modes, and to investigate the proposal of the utilisation of an RF volume ion source in he application of neutral beam injection (NBI) systems for the proposed nuclear fusion reactors of the future.
Tuned Langmuir probes are used as a diagnostic method to measure different plasma parameters as a function of pressure and power. The spatial variations of thes...

DENISE is an acronym for Deuterium Negative Ion Source Experiment and originated in FOM the Institute for Atomic and Molecular Physics in DCU where it is being recommissioned as a test bed for the production and extraction of negative hydrogen ion for use in proposed nuclear fusion reactors. These reactors require the neutralisation of particle beams of up to hundreds of amps and energies of about IMeV for use in Neutral Beam Injection (N.B.I.).
The objective of this project was to automate the multicusp volume ion source called DENISE.
Automation is the technology concerned with the application of mechanical, electronic, and computer-based systems in the operation and control of production. This process of technological development lends real-time monitoring and quick error detection and correction to parameters and components that need to be controlled. Another feature is the ease of use and the attraction of the safety features that are inherent in this technology.
The paramet...

McCarthy, Eanna; Rajendra Kumar, Ramasamy Thangavelu; Doggett, B.; Chakrabarti, S.; O'Haire, Richard J. ; Newcomb, Simon B.; Mosnier, Jean-Paul; Henry, Martin O.; McGlynn, Enda

Abstract:

We report x-ray diffraction (2θ-ω and rocking curve) and transmission electron microscopy measurements on crystallographically textured ZnO thin films of varying thicknesses and crystallite mosaic spread deposited by pulsed laser deposition on Si. The integrated areas of the (0002) ZnO reflections in 2θ-ω mode do not scale with film thickness and in some cases show discrepancies of two orders of magnitude compared to expectations based solely on sample thicknesses. Intensity differences of this type are regularly used in the literature as indications of differences in sample crystallinity or crystal quality. However transmission electron microscopy data of our samples show no evidence of amorphous deposits or significantly varying crystal quality in different films. X-ray rocking curves of these samples do show substantial variations in the mosaic spread of crystallites in the ZnO films which are the origin of the differences in integrated areas of the (0002) ZnO reflections in 2θ-ω...

<p>A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease.</p>
<p><strong>Methods:</strong></p>
<p>The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound,magnetic resonance imaging,x-raycomputed tomography, and x-raydigital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR rel...

<p>A new generation of ultrasound transient elastography (TE) systems have emerged which exploit the well-known correlation between the liver’s pathological and mechanical properties through measurements of the Young’s elastic modulus; however, little work has been carried out to examine the effect that fatty deposits may have on the TE measurement accuracy. An investigation was carried out on the effects on the measurement accuracy of a transient elastography ultrasound system, the Fibroscan®, caused by overlaying fat layers of varying thickness on healthy liver-mimicking phantoms, simulating in vivo conditions for obese patients. Furthermore, a steatosis effect similar to that in non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) was simulated to investigate its effect on the TE system. A range of novel elastography fat-mimicking materials were developed using 6-10wt% poly(vinyl alcohol) cryogel capable of achieving a range of acoustic velocities (14...

In this paper we present the parameterization of a new interionic potential for stoichiometric, reduced and doped CeO2. We use a dipole polarizable potential (DIPPIM: the dipole polarizable ion model) and optimize its parameters by fitting them to a series of density functional theory calculations. The resulting potential was tested by calculating a series of fundamental properties for CeO2 and by comparing them against experimental values. The values for all the calculated properties (thermal and chemical expansion coefficients, lattice parameters, oxygen migration energies, local crystalline structure and elastic constants) are within 10?15% of the experimental ones, an accuracy comparable to that of ab initio calculations. This result suggests the use of this new potential for reliably predicting atomic scale properties of CeO2 in problems where ab initio calculations are not feasible due to their size limitations.

Anomalous electrical transport properties of polyvinyl alcohol-multiwall
carbon nanotubes composites below room temperature
G. Chakraborty,
1
K. Gupta,
1
A. K. Meikap,
1,
a
R. Babu,
2
and W. J. Blau
2
1
Department of Physics, National Institute of Technology, Durgapur Mahatma Gandhi Avenue, Durgapur,
713209 West Bengal, India
2
Department of Physics, University of Dublin Trinity College, Dublin 2, Ireland
Received 29 September 2010; accepted 9 December 2010; published online 3 February 2011
The dc and ac electrical transport property of polyvinyl alcohol-multiwall carbon nanotubes
composites has been investigated within a temperature range 77
T
300 K and in the frequency
range 20 Hz?1 MHz in presence as well as in absence of a transverse magnetic field up to 1 T. The
dc conductivity follows variable range hopping model. The magnetoconductivity of the samples
changes a sign from positive to negative with an increase in temperature which can be interpreted
by the dominancy of the quan...

A dual spin valve is built with exchange bias on the top and bottom pinned layers and a central free layer. By suitable choice of the antiferromagnetic and ferromagnetic layer thicknesses, it is possible to separate the three magnetization switching fields and produce a staircase magnetoresistive curve. The maximum magnetoresistance (MR) ratio is 7.6% for current-perpendicular-to-plane and 6.3% for current-in-plane geometries with intermediate MRs of 3.9% and 3.0%, respectively. The use of exchange bias in a multistate memory device is discussed.

We use the recently found integral representation for the dressing phase in the kinematic region of the mirror theory to simplify the TBA equations for the AdS5 ? S5 mirror model. The resulting set of equations provides an efficient starting point for both analytic and numerical studies.

We use the string hypothesis for the mirror theory to derive the Thermodynamic Bethe Ansatz equations for the AdS5 ? S5 mirror model. We further demonstrate how these equations can be used to construct the associated Y-system recently discussed in the literature, putting particular emphasis on the assumptions and the range of validity of the corresponding construction.

peer-reviewed I review the current status of lattice calculations of heavy quark quantities. Particular emphasis is placed on
leptonic and semileptonic decay matrix elements.

Ultrathin films of Fe3O4 have been grown epitaxially on nearly lattice matched MgO(001). The stability of
4 nm thick films in ambient air and under annealing in an oxygen atmosphere at 200◦C has been studied. By
magneto optical and Raman measurements we can confirm the presence of the Fe3 O4 phase and the formation
of a maghemite top layer passivating the Fe3 O4 thin film. In a second step we are able to demonstrate that
this top layer oxidation in ambient air can be prevented by a 2 nm thick magnesium ferrite passivation layer,
while a thicker 20 nm MgO layer prevents oxidation even at elevated temperatures.

The standard model fermion spectrum, including a right handed neutrino,
can be obtained as a zeremode of the Dirac operator on a space
which is the product of complex projective spaces of complex dimension
two and three. The construction requires the introduction of topologically
non-trivial background gauge fields. By borrowing from ideas in Connes'
non-commutative geometry and making the complex spaces 'fuzzy' a matrix
approximation to the fuzzy space allows for three generations to
emerge. The generations are associated with three copies of space-time.
Higgs' fields and Yukawa couplings can be accommodated in the usual
way.

We compute quark and gluon propagators in 2-colour QCD at large baryon chemical potential µ. The gluon propagator is found to be antiscreened at intermediate µ and screened at large µ. The quark propagator is drastically modified in the superfluid region as a result of the formation of a superfluid gap.

The mass of a black hole is interpreted, in terms of thermodynamic potentials,
as being the enthalpy, with the pressure given by the cosmological constant.
The volume is then defined as being the Legendre transform of the pressure
and the resulting relation between volume and pressure is explored in the case
of positive pressure. A virial expansion is developed and a van der Waals
like critical point determined. The first law of black hole thermodynamics
includes a PdV term which modifies the maximal efficiency of a Penrose
process. It is shown that, in four dimensional space-time with a negative
cosmological constant, an extremal charged rotating black hole can have an
efficiency of up to 75%, while for an electrically neutral rotating back hole
this figure is reduced to 52%, compared to the corresponding values of 50%
and 29% respectively when the cosmological constant is zero.

<p>Soft condensed matter (SCM) physics has recently gained importance for a large class of engineering materials. The treatment of food materials from a soft matter perspective, however, is only at the surface and is gaining importance for understanding the complex phenomena and structure of foods. In this work, we present a theoretical treatment of navy beans from a SCM perspective to describe the hydration kinetics. We solve the transport equations within a porous matrix and employ the Flory–Huggin’s equation for polymer–solvent mixture to balance the osmotic pressure. The swelling of the legume seed is modelled as a moving boundary with an explicit transient equation. The model exhibits a good agreement with the experimental observations and is capable of explaining the stages of hydration. Sensitivity analysis indicated that the degree of hydration is dependent on the bean size and is also sensitive to the selection of the intrinsic permeability of the bean.</p>

Direct impinging synthetic jets are a proven method for heat transfer enhancement,
and have been subject to extensive research. However, despite the vast amount of research into
direct synthetic jet impingement, there has been little research investigating the effects of a
synthetic jet emanating from a heated surface, this forms the basis of the current research
investigation. Both single and multiple orifices are integrated into a planar heat sink forming a
synthetic jet, thus allowing the heat transfer enhancement and flow structures to be assessed.
The heat transfer analysis highlighted that the multiple orifice synthetic jet resulted in the
greatest heat transfer enhancements. The flow structures responsible for this were identified
using a combination of flow visualisation, thermal imaging and thermal boundary layer
analysis. The flow structure analysis identified that the synthetic jets decreased the thermal
boundary layer thickness resulting in a more effective convective he...

<p>For both nonrelativistic and relativistic Hamiltonians, the Complex Absorbing Potential (CAP) method has been applied extensively to calculate resonances in Physics and Chemistry. We study clusters of resonances for the perturbed Dirac operator near the real axis and, in the semiclassical limit, we establish the CAP method rigorously by showing that resonances are perturbed eigenvalues of the nonselfadjoint CAP Hamiltonian, and vice versa.</p>

Empirical data for 145 countries shows a strong correlation between the gross national income per capita and the political form of their governance, as specified by the so-called democracy index. We interpret this relationship in analogy to phase transitions between different states of matter, using concepts of statistical physics. Fertility rates play the role of binding energy in solid state physics.

McCaffrey, John G.; Bellert, D.; Leung, Allan W.K.; Breckenridge, W.H.

Abstract:

The Zn(4s2)·Ne[1Σ+] and the Zn(4s4pπ)·Ne[1Π1] states have been characterized by laser-induced fluorescence spectroscopy. Bond lengths were determined from simulations of the partially-resolved rotational structure of the 1Π ← 1Σ+ transitions, while bond strengths were estimated from a Birge–Sponer extrapolation with allowance for consistent errors resulting from similar procedures in the analogous Cd·Ne and Hg·Ne transitions. The van der Waals bonding in these states is discussed briefly and compared to that in the analogous M·RG states, where M=Mg, Zn, Cd, Hg and RG=Ne, Ar, Kr, Xe.