A generalized correlation for the effect of pressure on the isobaric heat capacity of gases

A generalized correlation is submitted for the deviation of the isobaric heat capacity of hydrocarbons from the ideal state. The range of conditions included is from reduced pressure = 0.2 - 15 and reduced temperature = 1.0 - 5.5. The curves presented have been based on data calculated from the Benedict - Webb - Rubin Equation of State, which is believed to be the most accurate method presently available for caleulating the heat capacity deviation. The results indicate that the order of magnitude of the correction ts quite large, especially in the critical region. The average absolute error of this correlation is approximately 4.2% from the data on which it was based, but errors as high as 16% may occur in the regions of high heat capacity deviation. This indicates that, whenever possible, specific data should be used in preference to a generalized correlation. Comparisons have been made with the correlations submitted by previous investigators, and the relative accuracies of all have been discussed. A comparison with experimental heat capacity data for nitrogen and oxygen has shown that the correlation is also suitable for non-polar gases; and there are indications, based on the experimental data, that this correlation is more accurate than the earlier correlations which have been published

Harvey Weiss Correspondence

Entries include a typed letter from the Maine State Library to New York children\u27s book author Harvey Weiss introducing the Maine Author Collection and notice that a description of his book would appear in Maine Library Association Bulletin, a typed letter from Weiss on personal stationery presenting a copy of Twenty-Four And Stanley, and a typed letter from the Maine State Library concerning the irrepressible Stanley and on receipt of the book for the Maine Author collection

Development and Lipid Composition of the Harpacticoid Copepod Nitocra Spinipes Reared on Different Diets

We reared the harpacticoid copepod Nitocra spinipes on diets of bacteria, a diatom, or a macroalga, evaluating survivorship and growth in short-term (≤ 1 generation) experiments. Lipid content of the copepods and their diets was measured and used as an index of nutrition. Although growth, survivorship and lipid content of N. spinipes were significantly greater when fed the diatom, which had the highest lipid content of the 3 diets, the copepod was able to develop from egg to adult when fed a lipid- poor bacterial diet. Furthermore, this species was able to go through developmental molts without the addition of food (6 individuals from a starved cohort of 25 made it to at least copepodite stage I), suggesting the uptake of dissolved organic matter for growth. This widespread estuarine benthic copepod apparently has the ability to survive on diverse and nutritionally poor diets, a quality that is useful in a variable, detritus-dominated environment

On the Absence of Photospheric Net Currents in Vector Magnetograms of Sunspots Obtained From Hinode (SOT/SP)

Various theoretical and observational results have been reported regarding the presence/absence of net electric currents in the sunspots. The limited spatial resolution of the earlier observations perhaps obscured the conclusions. We have analyzed 12 sunspots observed from Hinode (SOT/SP) to clarify the issue. The azimuthal and radial components of magnetic fields and currents have been derived. The azimuthal component of the magnetic field of sunspots is found to vary in sign with azimuth. The radial component of the field also varies in magnitude with azimuth. While the latter pattern is a confirmation of the interlocking combed structure of penumbral filaments, the former pattern shows that the penumbra is made up of a "curly interlocking combed" magnetic field. The azimuthally averaged azimuthal component is seen to decline much faster than 1/$\varpi$ in the penumbra, after an initial increase in the umbra, for all the spots studied. This confirms the confinement of magnetic fields and absence of a net current for sunspots as postulated by \cite{parker96}. The existence of a global twist for a sunspot even in the absence of a net current is consistent with a fibril-bundle structure of the sunspot magnetic fields.Comment: 15 pages, 4 figures, 1 table; accepted for publication in the ApJ Letter

Structural Time Series Models with Feedback Mechanisms

Structural time series models have applications in many different fields such as biology, economics, and meteorology. A structural time series model can be represented as a state-space model where the states of the system represent the unobserved components and the structural parameters have clear interpretations. This paper introduces a class of structural time series models that incorporate feedback from the latent components of the history. An iterative procedure is proposed for estimation. These models allow flexible and robust feedback mechanisms, have clear interpretations, and have a computationally efficient estimation procedure. They are applied to hormone data to characterize hormone secretion and to explore a potential feedback mechanism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65683/1/j.0006-341X.2000.00686.x.pd

Single-Receiver GPS Phase Bias Resolution

Existing software has been modified to yield the benefits of integer fixed double-differenced GPS-phased ambiguities when processing data from a single GPS receiver with no access to any other GPS receiver data. When the double-differenced combination of phase biases can be fixed reliably, a significant improvement in solution accuracy is obtained. This innovation uses a large global set of GPS receivers (40 to 80 receivers) to solve for the GPS satellite orbits and clocks (along with any other parameters). In this process, integer ambiguities are fixed and information on the ambiguity constraints is saved. For each GPS transmitter/receiver pair, the process saves the arc start and stop times, the wide-lane average value for the arc, the standard deviation of the wide lane, and the dual-frequency phase bias after bias fixing for the arc. The second step of the process uses the orbit and clock information, the bias information from the global solution, and only data from the single receiver to resolve double-differenced phase combinations. It is called "resolved" instead of "fixed" because constraints are introduced into the problem with a finite data weight to better account for possible errors. A receiver in orbit has much shorter continuous passes of data than a receiver fixed to the Earth. The method has parameters to account for this. In particular, differences in drifting wide-lane values must be handled differently. The first step of the process is automated, using two JPL software sets, Longarc and Gipsy-Oasis. The resulting orbit/clock and bias information files are posted on anonymous ftp for use by any licensed Gipsy-Oasis user. The second step is implemented in the Gipsy-Oasis executable, gd2p.pl, which automates the entire process, including fetching the information from anonymous ft

Glycinergic Transmission in the Mammalian Retina

Glycine and γ-aminobutyric acid (GABA) are the major inhibitory neurotransmitters in the retina. Approximately half of the amacrine cells release glycine at their synapses with bipolar, other amacrine, and ganglion cells. Glycinergic amacrine cells are small-field amacrine cells with vertically oriented dendrites and comprise more than 10 different morphological types. The retinal distributions of glycine receptor (GlyR) α1, α2, α3 and α4 subtypes have been mapped with subunit-specific antibodies. GlyRs were clustered at postsynaptic hot spots which showed selective distributions for the different subunits. As a rule, only one α subunit was expressed at a given postsynaptic site. The kinetic properties of GlyRs were measured by recording spontaneous inhibitory postsynaptic currents (sIPSCs) from identified retinal neurons in wild-type, Glra1spd-ot, Glra2 and Glra3 knockout mice. From observed differences of sIPSCs in wild-type and mutant mice, the cell-type specific subunit composition of GlyRs could be defined. OFF-cone bipolar cells and A-type ganglion cells receive prominent glycinergic input with fast kinetics that is mainly mediated by α1β GlyRs (decay time constant τ ∼ 5 ms). By contrast, AII amacrine cells express α3β GlyRs with medium fast kinetics (τ ∼ 11 ms). Narrow-field (NF) and wide-field amacrine cells contain predominantly α2β GlyRs with slow kinetics (τ ∼ 27 ms). Lastly, ON-starburst, narrow-field and wide-field amacrine cells in Glra2 knockout mice express α4β GlyRs with very slow kinetics (τ ∼ 70 ms)

Timing of descriptions shapes experience‐based risky choice

Risky decisions based on the combination of different sources of information (e.g., decisions from description‐plus‐experience) have mostly been ignored, as research has focused on examining each source separately. Across three experiments, we explore the intricate relationship between experience and description by manipulating when descriptive information about risky options is made available during an experience‐based task. The results show that the amount of prior experience moderates the way that descriptive information is considered and integrated in the decision‐making process: Descriptions affected behavior more when participants had little experience with the task, whereas their effect was less pronounced with extended experience. This relationship reversed when participants had access to foregone payoffs, with descriptions being considered more when participants had more time to interact with the task. Potential mechanisms and theoretical accounts are discussed with an emphasis on how the results and conclusions of the present work can be applied to the effective design of warning labels

Supersymmetric Dissipative Quantum Mechanics from Superstrings

Following the approach of Callan and Thorlacius applied to the superstring, we derive a supersymmetric extension of the non-local dissipative action of Caldeira and Leggett. The dissipative term turns out to be invariant under a group of superconformal transformations. When added to the usual kinetic term, it provides an example of supersymmetric dissipative quantum mechanics. As a by-product of our analysis, an intriguing connection to the homeotic/hybrid fermion model, proposed for CPT violation in neutrinos, appears.Comment: Latex, 16 page

Revising the Contours of History at Tell Leilan

Northern Mesopotamia’s low grain yield costs and high land transport costs were fundamental forces behind early state growth in the fifth-fourth millennia BC (Weiss1983, 1986, 1997). That development, as well as the southern Mesopotamian Uruk colonization in northern Mesopotamia, was terminated by the 5.2 ka BP abrupt climate change that persisted for two centuries (Weiss 2001). In its wake, northern Mesopotamia underwent the Ninevite 5 experience: four hundred years of reduced settlement size,limited political consolidation, and abridged contact with southern Mesopotamia (Weiss and Rova eds. 2002). In the Leilan IIId period, ca. 2600-2400 BC, at the end of the Ninevite 5 period, Leilan suddenly grew from village to city size, 90 hectares, and its politico-economic organization was transformed into a state apparatus (Weiss 1990). The reasons for this secondary state development are still unclear, but seems to have occurred synchronously across northern Mesopotamia and induced, briefly, the emulation of southern Mesopotamian administrative iconography (Weiss 1990)