6,755 research outputs found
The minimum transfer price of services
The minimum agreeable transfer price in a transfer of goods between autonomous divisions of a decentralised firm is given by what has become known as the general rule . According to this rule, the least price acceptable to the transferor division is the sum of the transferor\u27s incremental or outlay costs and any associated foregone contribution (opportunity cost). The same rule can be shown to apply to transfers of services as well as goods, provided that the transferor\u27s foregone contribution is interpreted in relation to the replacement cost of the services (professional time) transferred. Specifically, foregone contribution is defined as the minimum of the contribution margin available to the transferor from the services transferred and the replacement or outsource cost of those services. This measure of foregone contribution is analogous to Bonbright\u27s notion of deprival value and implies a more general general rule, upon which the minimum transfer price of services may be determined not by what those services offer in the way of contribution, but by their (lower) replacement or outsource cost
The Infrared and Radio Fluxes Densities of Galactic HII Regions
We derive infrared and radio flux densities of all ~1000 known Galactic HII
regions in the Galactic longitude range 17.5 < l < 65 degree. Our sample comes
from the Wide-Field Infrared Survey Explorer (WISE) catalog of Galactic \hii
regions \citep{anderson2014}. We compute flux densities at six wavelengths in
the infrared (GLIMPSE 8 microns, WISE 12 microns and 22 microns, MIPSGAL 24
microns, and Hi-GAL 70 microns and 160 microns) and two in the radio (MAGPIS 20
cm and VGPS 21 cm). All HII region infrared flux densities are strongly
correlated with their ~20 cm flux densities. All HII regions used here,
regardless of physical size or Galactocentric radius, have similar infrared to
radio flux density ratios and similar infrared colors, although the smallest
regions (pc), have slightly elevated IR to radio ratios. The colors
and , and and reliably select
HII regions, independent of size. The infrared colors of ~22 of HII
regions, spanning a large range of physical sizes, satisfy the IRAS color
criteria of \citet{wood1989} for HII regions, after adjusting the criteria to
the wavelengths used here. Since these color criteria are commonly thought to
select only ultra-compact HII regions, this result indicates that the true
ultra-compact HII region population is uncertain. Comparing with a sample of IR
color indices from star-forming galaxies, HII regions show higher
ratios. We find a weak trend of
decreasing infrared to ~20 cm flux density ratios with increasing , in
agreement with previous extragalactic results, possibly indicating a decreased
dust abundance in the outer Galaxy.Comment: 27 pages, 16 figures, 5 table
Development of a contra-rotating tidal current turbine and analysis of performance
A contra-rotating marine current turbine has a number of attractive features: nearzero reactive torque on the support structure, near-zero swirl in the wake, and high relative inter-rotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing tank demonstrated the feasibility of the concept. Power coefficients were high for such a small model and in excellent agreement with predictions, confirming the accuracy of the computational modelling procedures. Highfrequency blade loading data were obtained in the course of the experiments. These show the anticipated dynamic components for a contra-rotating machine. Flow visualization of the wake verified the lack of swirl behind the turbine. A larger machine is presently under construction for sea trials
Design and testing of a contra-rotating tidal current turbine
A contra-rotating marine current turbine has a number of attractive features: nearzero reactive torque on the support structure, near-zero swirl in the wake, and high relative inter-rotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing tank demonstrated the feasibility of the concept. Power coefficients were high for such a small model and in excellent agreement with predictions, confirming the accuracy of the computational modelling procedures. High-frequency blade loading data were obtained in the course of the experiments. These show the anticipated dynamic components for a contra-rotating machine. Flow visualization of the wake verified the lack of swirl behind the turbine. A larger machine is presently under construction for sea trials
Molecular line contamination in the SCUBA-2 450 {\mu}m and 850 {\mu}m continuum data
Observations of the dust emission using millimetre/submillimetre bolometer
arrays can be contaminated by molecular line flux, such as flux from 12CO. As
the brightest molecular line in the submillimetre, it is important to quantify
the contribution of CO flux to the dust continuum bands. Conversion factors
were used to convert molecular line integrated intensities to flux detected by
bolometer arrays in mJy per beam. These factors were calculated for 12CO line
integrated intensities to the SCUBA-2 850 {\mu}m and 450 {\mu}m bands. The
conversion factors were then applied to HARP 12CO 3-2 maps of NGC 1333 in the
Perseus complex and NGC 2071 and NGC 2024 in the Orion B molecular cloud
complex to quantify the respective 12CO flux contribution to the 850 {\mu}m
dust continuum emission. Sources with high molecular line contamination were
analysed in further detail for molecular outflows and heating by nearby stars
to determine the cause of the 12CO contribution. The majority of sources had a
12CO 3-2 flux contribution under 20 per cent. However, in regions of molecular
outflows, the 12CO can dominate the source dust continuum (up to 79 per cent
contamination) with 12CO fluxes reaching \sim 68 mJy per beam.Comment: Accepted 2012 April 19 for publication in MNRAS. 21 pages, 13
figures, 3 table
Accelerator performance analysis of the Fermilab Muon Campus
Fermilab is dedicated to hosting world-class experiments in search of new
physics that will operate in the coming years. The Muon g-2 Experiment is one
such experiment that will determine with unprecedented precision the muon
anomalous magnetic moment, which offers an important test of the Standard
Model. We describe in this study the accelerator facility that will deliver a
muon beam to this experiment. We first present the lattice design that allows
for efficient capture, transport, and delivery of polarized muon beams. We then
numerically examine its performance by simulating pion production in the
target, muon collection by the downstream beam line optics, as well as
transport of muon polarization. We finally establish the conditions required
for the safe removal of unwanted secondary particles that minimizes
contamination of the final beam.Comment: 10 p
The effect of a strong external radiation field on protostellar envelopes in Orion
We discuss the effects of an enhanced interstellar radiation field (ISRF) on
the observables of protostellar cores in the Orion cloud region. Dust radiative
transfer is used to constrain the envelope physical structure by reproducing
SCUBA 850 micron emission. Previously reported 13CO, C17O and H2CO line
observations are reproduced through detailed Monte Carlo line radiative
transfer models. It is found that the 13CO line emission is marginally
optically thick and sensitive to the physical conditions in the outer envelope.
An increased temperature in this region is needed in order to reproduce the
13CO line strengths and it is suggested to be caused by a strong heating from
the exterior, corresponding to an ISRF in Orion 10^3 times stronger than the
"standard" ISRF. The typical temperatures in the outer envelope are higher than
the desorption temperature for CO. The C17O emission is less sensitive to this
increased temperature but rather traces the bulk envelope material. The data
are only fit by a model where CO is depleted, except in the inner and outermost
regions where the temperature increases above 30-40 K. The fact that the
temperatures do not drop below approximately 25 K in any of the envelopes
whereas a significant fraction of CO is frozen-out suggest that the
interstellar radiation field has changed through the evolution of the cores.
The H2CO lines are successfully reproduced in the model of an increased ISRF
with constant abundances of 3-5x10^{-10}.Comment: 11 pages, 10 figures. Accepted for publication in A&
Mid-J CO Shock Tracing Observations of Infrared Dark Clouds I
Infrared dark clouds (IRDCs) are dense, molecular structures in the
interstellar medium that can harbour sites of high-mass star formation. IRDCs
contain supersonic turbulence, which is expected to generate shocks that
locally heat pockets of gas within the clouds. We present observations of the
CO J = 8-7, 9-8, and 10-9 transitions, taken with the Herschel Space
Observatory, towards four dense, starless clumps within IRDCs (C1 in
G028.37+00.07, F1 and F2 in G034.43+0007, and G2 in G034.77-0.55). We detect
the CO J = 8-7 and 9-8 transitions towards three of the clumps (C1, F1, and F2)
at intensity levels greater than expected from photodissociation region (PDR)
models. The average ratio of the 8-7 to 9-8 lines is also found to be between
1.6 and 2.6 in the three clumps with detections, significantly smaller than
expected from PDR models. These low line ratios and large line intensities
strongly suggest that the C1, F1, and F2 clumps contain a hot gas component not
accounted for by standard PDR models. Such a hot gas component could be
generated by turbulence dissipating in low velocity shocks.Comment: 14 pages, 8 figures, 5 tables, accepted by A&A, minor updates to
match the final published versio
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