9,691 research outputs found
Radioisotope thermal generator (RTG) power conditioner
New regulator: (a) permits operation with high-impedance radioisotope thermal generators at conversion efficiencies typically above 90%; (b) does not require input filtering; (c) eliminates current spiking; and (d) is simple, efficient, and reliable. Converter-charger pair could be adapted for other power levels by changing transistor, diode, capacitor bank, and inductor
Why is the ground state electron configuration for Lithium ?
The electronic ground state for Lithium is , and not . The
traditional argument for why this is so is based on a screening argument that
claims that the electron is better shielded by the electrons, and
therefore higher in energy then the configuration that includes the
electron. We show that this argument is flawed, and in fact the actual reason
for the ordering is because the electron-electron interaction energy is higher
for the repulsion than it is for the repulsion.Comment: 4 page
Multimodal transition and stochastic antiresonance in squid giant axons
The experimental data of N. Takahashi, Y. Hanyu, T. Musha, R. Kubo, and G.
Matsumoto, Physica D \textbf{43}, 318 (1990), on the response of squid giant
axons stimulated by periodic sequence of short current pulses is interpreted
within the Hodgkin-Huxley model. The minimum of the firing rate as a function
of the stimulus amplitude in the high-frequency regime is due to the
multimodal transition. Below this singular point only odd multiples of the
driving period remain and the system is highly sensitive to noise. The
coefficient of variation has a maximum and the firing rate has a minimum as a
function of the noise intensity which is an indication of the stochastic
coherence antiresonance. The model calculations reproduce the frequency of
occurrence of the most common modes in the vicinity of the transition. A linear
relation of output frequency vs. for above the transition is also
confirmed.Comment: 5 pages, 9 figure
Detection of subthreshold pulses in neurons with channel noise
Neurons are subject to various kinds of noise. In addition to synaptic noise,
the stochastic opening and closing of ion channels represents an intrinsic
source of noise that affects the signal processing properties of the neuron. In
this paper, we studied the response of a stochastic Hodgkin-Huxley neuron to
transient input subthreshold pulses. It was found that the average response
time decreases but variance increases as the amplitude of channel noise
increases. In the case of single pulse detection, we show that channel noise
enables one neuron to detect the subthreshold signals and an optimal membrane
area (or channel noise intensity) exists for a single neuron to achieve optimal
performance. However, the detection ability of a single neuron is limited by
large errors. Here, we test a simple neuronal network that can enhance the
pulse detecting abilities of neurons and find dozens of neurons can perfectly
detect subthreshold pulses. The phenomenon of intrinsic stochastic resonance is
also found both at the level of single neurons and at the level of networks. At
the network level, the detection ability of networks can be optimized for the
number of neurons comprising the network.Comment: 14 pages, 9 figure
(Un)Lawfully Beautiful: The Legal (De)Construction of Female Beauty
Beautiful women are more revered, more desirable, and often times more employable than average-looking women. Despite an everincreasing awareness of women\u27s issues today, little progress has been made to reverse the objectification of women\u27s bodies. This Note asserts that various courts are helping deconstruct the idea that beautiful women should receive preferential treatment in the workplace, simply because they are beautiful. This Note contends that the law progressively is challenging social assumptions that favor traditionally beautiful women by telling employers that they can no longer demand a certain level of female attractiveness in certain contexts. By deemphasizing the general importance of the female body, the law implicitly is doing women of all shapes and sizes, races and skin tones, a favor immeasurable by any scale
A Bioeconomic Analysis of the Northwestern Hawaiian Islands Lobster Fishery
Several surplus production-based bioeconomic models are applied to the Northwestern Hawaiian Islands (NWHI) commercial lobster fishery. The model which best explains the biological dynamics of the fishery is a modification of the Fox model developed by the authors. Economic costs are applied within a number of conceptual frameworks to develop the first integrated bioeconomic model of the fishery. In another development, the opportunity cost of labor based on crew share at the open access equilibrium level of fishing effort is used instead of proxy wage levels. Given the costs incurred, the fishery appears to be self-regulating in terms of long-term fishing effort for maximum sustainable yield.biological production models, fisheries economics, fisheries management, spiny lobster, slipper lobster, Environmental Economics and Policy, Resource /Energy Economics and Policy,
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Implicit Bias Predicts Liking of Ingroup Members Who Are Comfortable With Intergroup Interaction.
We test a novel framework for how ingroup members are perceived during intergroup interaction. Across three experiments, we found that, above and beyond egalitarian attitudes and motivations, White observers' automatic responses to Blacks (i.e., their implicit anti-Black bias) shaped their affiliation toward ingroup targets who appeared comfortable engaging in interracial versus same-race interaction. White observers' implicit anti-Black bias negatively correlated with liking of White targets who were comfortable with Blacks (Experiments 1-3). The relationship between implicit bias and liking varied as a function of targets' nonverbal comfort in interracial interactions (Experiment 1). Specifically, implicit bias negatively correlated with liking of targets when targets' nonverbal behaviors revealed observers felt comfortable with interracial contact, irrespective of the nature of those behaviors (Experiment 2). Finally, the relationship between implicit bias and target liking was mediated by perceived similarity (Experiment 3). Theoretical implications for stigma-by-association, social network homogeneity, and extended contact are discussed
Span Programs and Quantum Space Complexity
While quantum computers hold the promise of significant computational speedups, the limited size of early quantum machines motivates the study of space-bounded quantum computation. We relate the quantum space complexity of computing a function f with one-sided error to the logarithm of its span program size, a classical quantity that is well-studied in attempts to prove formula size lower bounds.
In the more natural bounded error model, we show that the amount of space needed for a unitary quantum algorithm to compute f with bounded (two-sided) error is lower bounded by the logarithm of its approximate span program size. Approximate span programs were introduced in the field of quantum algorithms but not studied classically. However, the approximate span program size of a function is a natural generalization of its span program size.
While no non-trivial lower bound is known on the span program size (or approximate span program size) of any concrete function, a number of lower bounds are known on the monotone span program size. We show that the approximate monotone span program size of f is a lower bound on the space needed by quantum algorithms of a particular form, called monotone phase estimation algorithms, to compute f. We then give the first non-trivial lower bound on the app
Development of the Marital Attitudes and Expectations Scale, The
2012 Summer.Includes bibliographical references.Attitudes towards marital relationships have been examined in three ways in the literature. Studies focus on intent to marry, global positive or negative attitudes towards marriage, and expectations for what married life will be like. There are currently no instruments capable of assessing all three of these areas. The present study outlines the development and validation of the Marital Attitudes and Expectations Scale (MAES). The MAES is an instrument designed to measure intent to marry (Intent to Marry Scale, IMS), general attitudes towards marriage (General Attitudes towards Marriage Scale, GAMS), and expectations for marital relationships (Aspects of Marriage Scale, AMS). The MAES is composed of 36-items, and is on a 7-point Likert scale. The MAES is also designed to be applicable for any individual, regardless of marital status or sexual orientation. Results demonstrated internal reliability and construct validity for the instrument
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