6,310 research outputs found

    The Immigrant Housing Market: Analyses for Australia

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    This paper examines the immigrant adjustment process in Australia from the perspective of the housing market. It shows that immigrant “catch-up” to the native born in the housing market is much more rapid than in the labour market. A decomposition of the estimated coefficients of a logit model of tenure choice is developed that gives formal recognition to the immigrant adjustment process. The results from this decomposition demonstrate the importance of taking account of immigrant adjustment when seeking to understand variations in rates of home ownership across birthplace groups.

    Assessment of the Lunar Surface Layer and in Situ Materials to Sustain Construction-related Applications

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    Present and future technologies to facilitate lunar composition and resource assessment with applications to lunar surface construction are presented. We are particularly interested in the construction activity associated with lunar-based astronomy. We address, as an example, the use of ground-probing radar to help assess subsurface conditions at sites for observatories and other facilities

    Evidence for Factorization in Three-body Bˉ→D(∗)K−K0\bar B\to D^{(*)} K^- K^0 Decays

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    Motivated by experimental results on Bˉ→D(∗)K−K0\bar B\to D^{(*)}K^-K^{0}, we use a factorization approach to study these decays. Two mechanisms concerning kaon pair production arise: current-produced (from vacuum) and transition (from the BB meson). The kaon pair in the Bˉ0→D(∗)+K−K0\bar B {}^0\to D^{(*)+}K^-K^0 decays can be produced only by the vector current (current-produced), whose matrix element can be extracted from e+e−→KKˉe^+e^-\to K\bar K processes via isospin relations. The decay rates obtained this way are in good agreement with experiment. The B−→D(∗)0K−K0B^-\to D^{(*)0}K^-K^0 decays involve both current-produced and transition processes. By using QCD counting rules and the measured B−→D(∗)0K−K0B^-\to D^{(*)0} K^- K^0 decay rates, the measured decay spectra can be understood.Comment: 3 pages, 6 figures. Talk presented at EPS2003 Conference, Aachen, Germany, July 200

    Singing the Brain Electric

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    Thesis (S.M. in Science Writing)--Massachusetts Institute of Technology, Dept. of Humanities, Graduate Program in Science Writing, 2008.Includes bibliographical references (p. [36]-[38]).Singing the Brain Electric Brain pacemakers, scientists have found, can treat depression by correcting neural circuitry gone haywire. This thesis examines how such technology - a technique known as deep-brain stimulation, in which electrodes are implanted within the brain - was developed and how it works. We are introduced to a patient who received deep-brain stimulation for her refractory depression, and consider the risks, ethical issues, and questions of humanity and identity the technology raises.by Grace Chua.S.M.in Science Writin

    A priori prediction of aggregation efficiency and rate constant for fluidized bed melt granulation

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    This paper presents a predictive aggregation rate model for spray fluidized bed melt granulation. The aggregation rate constant was derived from probability analysis of particle–droplet contact combined with time scale analysis of droplet solidification and granule–granule collision rates. The latter was obtained using the principles of kinetic theory of granular flow (KTGF). The predicted aggregation rate constants were validated by comparison with reported experimental data for a range of binder spray rate, binder droplet size and operating granulator temperature. The developed model is particularly useful for predicting particle size distributions and growth using population balance equations (PBEs)

    InGaN nano-ring structures for high-efficiency light emitting diodes

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    A technique based on the Fresnel diffraction effect for the fabrication of nano-scale site-controlled ring structures in InGaN/GaN multi-quantum well structures has been demonstrated. The ring structures have an internal diameter of 500 nm and a wall width of 300 nm. A 1 cm-1 Raman shift has been measured, signifying substantial strain relaxation from the fabricated structure. The 9 nm blueshift observed in the cathodoluminescence spectra can be attributed to band filling and/or screening of the piezoelectric field. A light emitting diode based on this geometry has been demonstrated

    Neutrino mass induced radiatively by supersymmetric leptoquarks

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    We show how nonzero Majorana neutrino masses can be radiatively generated by extending the MSSM with leptoquark chiral multiplets without violating R-parity. It is found that, with these particles, the R-parity conservation does not imply lepton number conservation. Neutrino masses generated at a one-loop level are closely related to the down quark mass matrix. The ratio of neutrino mass-squared splittings ΔmÎœ2−Μ12/ΔmÎœ3−Μ22\Delta m^2_{\nu_2-\nu_1}/\Delta m^2_{\nu_3-\nu_2} obtained is naturally close to Δms−d2/Δmb−s2∌10−3\Delta m^2_{s-d}/\Delta m^2_{b-s}\sim 10^{-3} which is in the right region required to explain both the atmospheric neutrino data and the MSW solutions for the solar neutrino data.Comment: 13 pages, one figure, more constraints added. To appear in Phys. Lett.

    Adjuvant Migraine Medications in the Treatment of Sudden Sensorineural Hearing Loss.

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    Objectives/hypothesisTo examine the hearing outcomes of patients with sudden sensorineural hearing loss (SSNHL) treated with oral and intratympanic (IT) steroid only or a combination of steroid and migraine treatment. Our hypothesis was that adjuvant migraine medications may improve outcomes in SSNHL.MethodsA retrospective chart review at a tertiary otology center was conducted to identify patients with SSNHL who received oral steroid and IT dexamethasone injection(s) with or without migraine medications (a combination of nortriptyline and topiramate).ResultsA total of 47 patients received oral steroid and IT dexamethasone injection(s) only, and 46 patients received oral steroid and IT dexamethasone injection(s) as well as migraine lifestyle changes plus a combination of nortriptyline and topiramate. There were no significant differences in demographics and baseline audiometric data between the two groups. Both groups demonstrated improvements in pure tone average (PTA) and hearing thresholds at 250 Hz and 8000 Hz posttreatment. However, compared to steroid-only group, the adjuvant migraine medications group had significantly greater improvements in hearing thresholds at the lower frequencies (250 Hz, 500 Hz, 1000 Hz). Patients in the latter cohort also had greater improvement in PTA (P = .01) and received fewer IT injections (P = .04) PTA improvement of ≄ 10 dB was observed in 36 patients (78%) in the adjuvant migraine medications group and 22 patients (46%) in the control group (P < .001).ConclusionIn multimodal treatment of SSNHL, supplementing oral and IT steroid with migraine medications may result in greater improvements in lower frequency hearing thresholds and PTA. Furthermore, adjuvant migraine treatment can lead to decrease in number of IT injections, thus reducing procedure-related risks and complications.Level of evidence3 Laryngoscope, 131:E283-E288, 2021

    Memory difference control of unknown unstable fixed points: Drifting parameter conditions and delayed measurement

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    Difference control schemes for controlling unstable fixed points become important if the exact position of the fixed point is unavailable or moving due to drifting parameters. We propose a memory difference control method for stabilization of a priori unknown unstable fixed points by introducing a memory term. If the amplitude of the control applied in the previous time step is added to the present control signal, fixed points with arbitrary Lyapunov numbers can be controlled. This method is also extended to compensate arbitrary time steps of measurement delay. We show that our method stabilizes orbits of the Chua circuit where ordinary difference control fails.Comment: 5 pages, 8 figures. See also chao-dyn/9810029 (Phys. Rev. E 70, 056225) and nlin.CD/0204031 (Phys. Rev. E 70, 046205

    Time scale analysis for fluidizedbedmeltgranulation III: binder solidification rate

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    In series I and II of this study ([Chua et al., 2010a] and [Chua et al., 2010b]), we discussed the time scale of granule–granule collision, droplet–granule collision and droplet spreading in Fluidized Bed Melt Granulation (FBMG). In this third one, we consider the rate at which binder solidifies. Simple analytical solution, based on classical formulation for conduction across a semi-infinite slab, was used to obtain a generalized equation for binder solidification time. A multi-physics simulation package (Comsol) was used to predict the binder solidification time for various operating conditions usually considered in FBMG. The simulation results were validated with experimental temperature data obtained with a high speed infrared camera during solidification of ‘macroscopic’ (mm scale) droplets. For the range of microscopic droplet size and operating conditions considered for a FBMG process, the binder solidification time was found to fall approximately between 10-3 and 10-1 s. This is the slowest compared to the other three major FBMG microscopic events discussed in this series (granule–granule collision, granule–droplet collision and droplet spreading)
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