Non-Gaussianity analysis of GW background made by short-duration burst signals

We study an observational method to analyze non-Gaussianity of a gravitational wave (GW) background made by superposition of weak burst signals. The proposed method is based on fourth-order correlations of data from four detectors, and might be useful to discriminate the origin of a GW background. With a formulation newly developed to discuss geometrical aspects of the correlations, it is found that the method provides us with linear combinations of two interesting parameters, I_2 and V_2 defined by the Stokes parameters of individual GW burst signals. We also evaluate sensitivities of specific detector networks to these parameters.Comment: 18 pages, to appear in PR

Prospects for direct detection of circular polarization of gravitational-wave background

We discussed prospects for directly detecting circular polarization signal of gravitational wave background. We found it is generally difficult to probe the monopole mode of the signal due to broad directivity of gravitational wave detectors. But the dipole (l=1) and octupole (l=3) modes of the signal can be measured in a simple manner by combining outputs of two unaligned detectors, and we can dig them deeply under confusion and detector noises. Around f~0.1mHz LISA will provide ideal data streams to detect these anisotropic components whose magnitudes are as small as ~1 percent of the detector noise level in terms of the non-dimensional energy density \Omega_{GW}(f).Comment: 5 pages, 1 figure, PRL in pres

Crystallization kinetics of binary colloidal monolayers

Experiments and simulations are used to study the kinetics of crystal growth in a mixture of magnetic and nonmagnetic particles suspended in ferrofluid. The growth process is quantified using both a bond order parameter and a mean domain size parameter. The largest single crystals obtained in experiments consist of approximately 1000 particles and form if the area fraction is held between 65-70% and the field strength is kept in the range of 8.5-10.5 Oe. Simulations indicate that much larger single crystals containing as many as 5000 particles can be obtained in impurity-free conditions within a few hours. If our simulations are modified to include impurity concentrations as small as 1-2%, then the results agree quantitatively with the experiments. These findings provide an important step toward developing strategies for growing single crystals that are large enough to enable follow-on investigations across many subdisciplines in condensed matter physics.Comment: 10 pages, 11 figure

Nonlinear Velocity-Density Coupling: Analysis by Second-Order Perturbation Theory

Cosmological linear perturbation theory predicts that the peculiar velocity $V(x)$ and the matter overdensity $\delta(x)$ at a same point $x$ are statistically independent quantities, as log as the initial density fluctuations are random Gaussian distributed. However nonlinear gravitational effects might change the situation. Using framework of second-order perturbation theory and the Edgeworth expansion method, we study local density dependence of bulk velocity dispersion that is coarse-grained at a weakly nonlinear scale. For a typical CDM model, the first nonlinear correction of this constrained bulk velocity dispersion amounts to $\sim 0.3\delta$ (Gaussian smoothing) at a weakly nonlinear scale with a very weak dependence on cosmological parameters. We also compare our analytical prediction with published numerical results given at nonlinear regimes.Comment: 16 pages including 2 figures, ApJ 537 in press (July 1

Signature of the Overhauser field on the coherent spin dynamics of donor-bound electron in a single CdTe quantum well

We have studied the coherent spin dynamics in an oblique magnetic field of electrons localized on donors and placed in the middle of a single CdTe quantum well, by using a time-resolved optical technique: the photo-induced Faraday rotation. We showed that this dynamics is affected by a weak Overhauser field created via the hyperfine interaction of optically spin-polarized donor-bound electrons with the surrounding nuclear isotopes carrying non-zero spins. We have measured this nuclear field, which is on the order of a few mT and can reach a maximum experimental value of 9.4 mT. This value represents 13 % of the maximal nuclear polarization, and corresponds also to 13 % of maximal electronic polarization.Comment: 15 pages, 4 figure

Detecting the Cosmic Gravitational Wave Background with the Big Bang Observer

The detection of the Cosmic Microwave Background Radiation (CMB) was one of the most important cosmological discoveries of the last century. With the development of interferometric gravitational wave detectors, we may be in a position to detect the gravitational equivalent of the CMB in this century. The Cosmic Gravitational Background (CGB) is likely to be isotropic and stochastic, making it difficult to distinguish from instrument noise. The contribution from the CGB can be isolated by cross-correlating the signals from two or more independent detectors. Here we extend previous studies that considered the cross-correlation of two Michelson channels by calculating the optimal signal to noise ratio that can be achieved by combining the full set of interferometry variables that are available with a six link triangular interferometer. In contrast to the two channel case, we find that the relative orientation of a pair of coplanar detectors does not affect the signal to noise ratio. We apply our results to the detector design described in the Big Bang Observer (BBO) mission concept study and find that BBO could detect a background with $\Omega_{gw} > 2.2 \times 10^{-17}$.Comment: 15 pages, 12 Figure

Mobile Application “Pramuka dalam Android” sebagai Media Pendukung Pembelajaran Materi Pramuka

Android merupakan sistem operasi mobile yang open platform, yaitu sistem operasi yang memungkinkan pihak ketiga untuk melakukan pengembangan-pengembangan dalam aplikasinya. Hal tersebut mendorong minat para pengembang semakin tinggi untuk berinovasi dalam menciptakan aplikasi-aplikasi baru yang dapat memenuhi kebutuhan konsumen baik terhadap hiburan, informasi umum maupun pendidikan. Salah satu bentuk kebutuhan akan pendidikan yaitu pendidikan kepribadian dan ketrampilan, yang terkemas dalam suatu latihan Kepramukaan. Materi yang diajarkan dalam Pramuka meliputi Kode Kehormatan Pramuka, Morse, Semaphore, Sandi, Tali temali, Perkemahan, Tanda Jejak dan Baris-berbaris. Pendidikan Pramuka sangat berperan dalam membentuk karakter bangsa yang unggul, sehingga pembelajaran dalam Kepramukaan pun menjadi sangat penting untuk diperhatikan. Saat ini diperlukan metode pembelajaran meteri Pramuka yang lebih dinamis dan menarik agar para anggota Pramuka lebih tertarik dalam mempelajarinya. Atas latar belakang masalah tersebutlah maka penelitian ini dibuat dengan tujuan memanfaatkan perangkat smartphone Android sebagai media pendukung dalam pembelajaran materi Pramuka. Hasil dari penelitian ini adalah suatu mobile application “Pramuka Dalam Android” yang berisi tentang materi-materi yang terdapat dalam Pramuka. Mobile application ini dibangun dengan software Adobe Flash CS5.5 dan bahasa scripting ActionScript 3.0

Beyond Technology: Demand-Side Solutions for Climate Change Mitigation

The assessment literature on climate change solutions to date has emphasized technologies and options based on cost-effectiveness analysis. However, many solutions to climate change mitigation misalign with such analytical frameworks. Here, we examine demand-side solutions, a crucial class of mitigation options that go beyond technological specification and costbenefit analysis. To do so, we synthesize demand-side mitigation options in the urban, building, transport, and agricultural sectors. We also highlight the specific nature of demand-side solutions in the context of development. We then discuss key analytical considerations to integrate demand-side options into overarching assessments on mitigation. Such a framework would include infrastructure solutions that interact with endogenous preference formation. Both hard infrastructures, such as the built environment, and soft infrastructures, such as habits and norms, shape behavior and as a consequence offer significant potential for reducing overall energy demand and greenhouse gas emissions. We conclude that systemic infrastructural and behavioral change will likely be a necessary component of a transition to a low-carbon society

Prevalence and predictors of compliance with discontinuation of airborne isolation in patients with suspected pulmonary tuberculosis

OBJECTIVE: Examine the use of airborne isolation by identifying reasons for nontimely discontinuation and predictors of compliance with Centers for Disease Control and Prevention (CDC) guidelines. Compliance with guidelines should result in timely (within 48 hours) discontinuation of isolation in patients without infectious pulmonary tuberculosis (TB). DESIGN: Retrospective, observational study. SETTING: A private, university-affiliated, tertiary-care medical center. PATIENTS: All patients in airborne isolation for suspected pulmonary TB from June through December 2011. METHOD: Chart reviews were performed to identify airborne isolation practices and delayed (greater than 48 hours) or very delayed (greater than 72 hours) discontinuation. We used descriptive statistics and logistic regression to determine independent predictors of nontimely discontinuation of isolation. RESULTS: We identified 113 patients (mean age ± standard deviation, 59.8 ± 17.7 years; male sex, 75.2%; white race, 15.9%; mean collection interval ± standard deviation, 21.4 ± 12.9 hours). Delayed and very delayed isolation discontinuation was noted in 81% and 49% of patients, respectively. No significant differences in demographic characteristics and clinical characteristics were identified between groups. Predictors of timely (within 48 hours) airborne isolation discontinuation included use of alternate diagnosis for discontinuation of isolation (P = .02), early infectious diseases (ID) consultation (P = .03), pulmonary consultation (P = .02), average sputum collection interval less than 24 hours (P = .03), and need for more than 1 induced sputum specimen (P = .05). Adjusting for potential confounders, pulmonary consultation (odds ratio [OR] [95% confidence interval (CI)], 0.14 [0.03–0.58]), alternate diagnosis for discontinuation of isolation (OR [95% CI], 4.5 [1.3–15.8]), and early ID consultation (OR [95% CI], 4.0 [1.1–14.8]) were independently associated with timely discontinuation. CONCLUSIONS: Timely airborne isolation discontinuation occurs in only 18.6% of cases and is an opportunity for cost savings, improved efficiency, and potentially patient safety and satisfaction