33,700 research outputs found
Buy, Lobby or Sue: Interest Groups' Participation in Policy Making - A Selective Survey
The participation of interest groups in public policy making is unavoidable. Its unavoidable nature is only matched by the universal suspicion with which it has been seen by both policy makers and the public. Recently, however, there has been a growing literature that examines the participation of interest groups in public policy making from a New Institutional Economics perspective. The distinguishing feature of the New Institutional Economics Approach is its emphasis in opening up the black box of decision-making, whether in understanding the rules of the game, or the play of the game. In this paper we do not attempt to fairly describe the vast literature on interest group's behavior. Instead, the purpose of this essay for the New Institutional Economics Guide Book is to review recent papers that follow the NIE mantra. That is, they attempt to explicate the micro-analytic features of the way interest groups actually interact with policy-makers, rather than providing an abstract high-level representation. We emphasize the role of the institutional environment in understanding interest groups' strategies.
Rectification of energy and motion in non-equilibrium parity violating metamaterials
Uncovering new mechanisms for rectification of stochastic fluctuations has
been a longstanding problem in non-equilibrium statistical mechanics. Here,
using a model parity violating metamaterial that is allowed to interact with a
bath of active energy consuming particles, we uncover new mechanisms for
rectification of energy and motion. Our model active metamaterial can generate
energy flows through an object in the absence of any temperature gradient. The
nonreciprocal microscopic fluctuations responsible for generating the energy
flows can further be used to power locomotion in, or exert forces on, a viscous
fluid. Taken together, our analytical and numerical results elucidate how the
geometry and inter-particle interactions of the parity violating material can
couple with the non-equilibrium fluctuations of an active bath and enable
rectification of energy and motion.Comment: 9 Pages + S
Metal-Insulator Transition of the LaAlO3-SrTiO3 Interface Electron System
We report on a metal-insulator transition in the LaAlO3-SrTiO3 interface
electron system, of which the carrier density is tuned by an electric gate
field. Below a critical carrier density n_c ranging from 0.5-1.5 * 10^13/cm^2,
LaAlO3-SrTiO3 interfaces, forming drain-source channels in field-effect devices
are non-ohmic. The differential resistance at zero channel bias diverges within
a 2% variation of the carrier density. Above n_c, the conductivity of the ohmic
channels has a metal-like temperature dependence, while below n_c conductivity
sets in only above a threshold electric field. For a given thickness of the
LaAlO3 layer, the conductivity follows a sigma_0 ~(n - n_c)/n_c characteristic.
The metal-insulator transition is found to be distinct from that of the
semiconductor 2D systems.Comment: 4 figure
Measuring and analysing vibration motors in insoles via accelerometers
Purpose: Falling is a major public health concern among elderly people, and they often cause serious injuries1,2. They most frequently occur during walking and are associated with the chronic deterioration in the neuromuscular and sensory systems, as well as with ankle muscle weakness and lower endurance of these muscles to fatigue1,3. Vibrating insoles, providing a subsensory mechanical noise signal to the plantar side of the feet, may improve balance in healthy young and older people and in patients with stroke or diabetic neuropathy4. The object of this study is to find the most suitable vibrator to put into the insole which can effectively improve the balance control of the elderlies. Method: We choose three different vibration actuators (micro vibration motor, brushless motor and eccentric motor) with two different weights on the insole. First, we put three same motors and two accelerometers on the insole, as shown in Figure1, then attach another layer on both side of the insole. Second, connect the motors to the power supply and the accelerometer to NI PXI-1033 spectrum analyzer which is used to collect the accelerometers' data. At last, using Fast Fourier Transform (FFT) to analyze and compare the results to see which motor is the most stable and suitable to put into the insole. Results & Discussion: The results showed that the most stable one is the brushless motor. The reason why the frequency is stable is that the relationship between voltage and frequency is linear, and the error is small through continuous measurements. On the other hand, when a person weight 55 kg stands on the insole, the frequency isn't affected by the weight. These two results appear very similar to each other, as shown in Figure 2. According to the result, we use the brushless motor to be our vibrator in the insole, and hope this will help the elderlies improve their balance control ability more efficiency
Alignment and orientation of an adsorbed dipole molecule
Half-cycle laser pulse is applied on an absorbed molecule to investigate its
alignment and orientation behavior. Crossover from field-free to hindered
rotation motion is observed by varying the angel of hindrance of potential
well. At small hindered angle, both alignment and orientation show
sinusoidal-like behavior because of the suppression of higher excited states.
However, mean alignment decreases monotonically as the hindered angle is
increased, while mean orientation displays a minimum point at certain hindered
angle. The reason is attributed to the symmetry of wavefunction and can be
explained well by analyzing the coefficients of eigenstates.Comment: 4 pages, 4 figures, to appear in Phys. Rev. B (2004
Observations of HONO by laser-induced fluorescence at the South Pole during ANTCI 2003
Observations of nitrous acid (HONO) by laser-induced fluorescence (LIF) at the South Pole taken during the Antarctic Troposphere Chemistry Investigation (ANTCI), which took place over the time period of Nov. 15, 2003 to Jan. 4, 2004, are presented here. The median observed mixing ratio of HONO 10 m above the snow was 5.8 pptv (mean value 6.3 pptv) with a maximum of 18.2 pptv on Nov 30th, Dec 1st, 3rd, 15th, 17th, 21st, 22nd, 25th, 27th and 28th. The measurement uncertainty is ±35%. The LIF HONO observations are compared to concurrent HONO observations performed by mist chamber/ion chromatography (MC/IC). The HONO levels reported by MC/IC are about 7.2 ± 2.3 times higher than those reported by LIF. Citation: Liao, W., A. T. Case, J. Mastromarino, D. Tan, and J. E. Dibb (2006), Observations of HONO by laser-induced fluorescence at the South Pole during ANTCI 2003, Geophys. Res. Lett., 33, L09810, doi:10.1029/2005GL025470
Symmetry, dark matter and LHC phenomenology of the minimal SM
A sterile neutrino with a mass of a few keV can play the role of a warm dark
matter(DM). This can be realized in seesaw models with 3 left- and 3
right-handed neutrinos. It is possible to identify the keV neutrino to be one
of the right-handed neutrinos leaving the other two to be much more heavier,
the SM model. We show that with this realization of keV neutrino DM, the
model has an approximate Friedberg-Lee symmetry providing a natural explanation
for the lightness of the right-handed neutrino. We also find that in this model
the mixing parameters couple light and heavy neutrinos are strongly correlated,
and can be large enough to have testable effects at the LHC for the two heavy
right-handed neutrinos to be in the hundred-GeV range.Comment: 20 pages, 5 figures, discussions expanded, references added, to
appear in PR
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