12,130 research outputs found
Precision control system for engine fuel
System controls two or more pneumatically operated metering valves from common pneumatic source without interaction between valve controls. Unit affords independent metering of liquid from single source to two concurrent applications. Calibration and testing demonstrate complete absence of interaction between valves and corresponding flow rates
A Note on the Fine Structure of Myoskeletal Junctions in Acartia tonsa Dana (Copepoda, Calanoida)
The endoskeleton of the calanoid copepod, Calanus finmarchicus, and its muscle attachments were described by Lowe (1935). She reported that the endoskeleton in C. finmarchicus consists of two tendinous endosternites and chitinous exoskeletal ingrowths to which muscles are attached. Howse (1960) noted attachments of the main muscles of the thorax to the exoskeleton in Acartia tonsa.
Bouligand (1962) described the ultrastructure of muscle attachments to cuticle in three species of freshwater copepods of the genus Cyclops. Raymont et al. (1974) described the fine structure of muscle attachments to cuticle in C. finmarchicus.
Information of the internal anatomy of marine copepods remains sparse. Therefore, we thought it worthwhile to focus our observations on the attachments of muscle to exoskeletal ingrowths in A. tonsa
A Note on the Fine Structure of Myoskeletal Junctions in Acartia tonsa Dana (Copepoda, Calanoida)
The endoskeleton of the calanoid copepod, Calanus finmarchicus, and its muscle attachments were described by Lowe (1935). She reported that the endoskeleton in C. finmarchicus consists of two tendinous endosternites and chitinous exoskeletal ingrowths to which muscles are attached. Howse (1960) noted attachments of the main muscles of the thorax to the exoskeleton in Acartia tonsa.
Bouligand (1962) described the ultrastructure of muscle attachments to cuticle in three species of freshwater copepods of the genus Cyclops. Raymont et al. (1974) described the fine structure of muscle attachments to cuticle in C. finmarchicus.
Information of the internal anatomy of marine copepods remains sparse. Therefore, we thought it worthwhile to focus our observations on the attachments of muscle to exoskeletal ingrowths in A. tonsa
Relationships Between Physical Measurements and Calving Difficulty in Two-Year-Old Santa Gertrudis Heifers
Last updated: 6/1/200
The Double Quasar Q2138-431: Lensing by a Dark Galaxy?
We report the discovery of a new gravitational lens candidate Q2138-431AB,
comprising two quasar images at a redshift of 1.641 separated by 4.5 arcsecs.
The spectra of the two images are very similar, and the redshifts agree to
better than 115 km.sec. The two images have magnitudes and
, and in spite of a deep search and image subtraction procedure, no
lensing galaxy has been found with . Modelling of the system
configuration implies that the mass-to-light ratio of any lensing galaxy is
likely to be around , with an absolute lower limit of
for an Einstein-de Sitter universe. We conclude that
the most likely explanation of the observations is gravitational lensing by a
dark galaxy, although it is possible we are seeing a binary quasar.Comment: 17 pages (Latex), 8 postscript figures included, accepted by MNRA
Synchronization of estrus and ovulation in dairy heifers using norgestomet, GnRH, and PGF2α
Two experiments were performed using the same treatments. All heifers received two injections of PGF2α 14 days apart. Controls then were inseminated after detected estrus. Heifers assigned to the two treatments also received 6 mg of norgestomet for 8 days beginning 7 days before the second of two PGF2α injections. The heifers in the last treatment also received GnRH 48 hr after the second PGF2α injection to induce ovulation in any heifer not observed in estrus before a fixed-time insemination at 72 hr after PGF2α. In Experiment 1, any control heifer or herifer in the two treatments not detected in estrus by 72 hr after PGF2α received a fixed-time insemination at 72 hr. Heifers receiving GnRH tended to have fewer standing events and a shorter duration of estrus. Fixed-time inseminations reduced conception compared to those after detected estrus. In Experiment 2, when inseminations were performed only after detected estrus, all measures of fertility were unaffected by treatments. These results indicated that addition of norgestomet and(or) GnRH did not improve measures of estrus synchronization or fertility of dairy heifers.; Dairy Day, 1997, Kansas State University, Manhattan, KS, 1997
On the relationship between sigma models and spin chains
We consider the two-dimensional non-linear sigma model with
topological term using a lattice regularization introduced by Shankar and Read
[Nucl.Phys. B336 (1990), 457], that is suitable for studying the strong
coupling regime. When this lattice model is quantized, the coefficient
of the topological term is quantized as , with integer or
half-integer. We study in detail the relationship between the low energy
behaviour of this theory and the one-dimensional spin- Heisenberg model. We
generalize the analysis to sigma models with other symmetries.Comment: To appear in Int. J. MOd. Phys.
Application of a Self-Similar Pressure Profile to Sunyaev-Zel'dovich Effect Data from Galaxy Clusters
We investigate the utility of a new, self-similar pressure profile for
fitting Sunyaev-Zel'dovich (SZ) effect observations of galaxy clusters. Current
SZ imaging instruments - such as the Sunyaev-Zel'dovich Array (SZA) - are
capable of probing clusters over a large range in physical scale. A model is
therefore required that can accurately describe a cluster's pressure profile
over a broad range of radii, from the core of the cluster out to a significant
fraction of the virial radius. In the analysis presented here, we fit a radial
pressure profile derived from simulations and detailed X-ray analysis of
relaxed clusters to SZA observations of three clusters with exceptionally high
quality X-ray data: A1835, A1914, and CL J1226.9+3332. From the joint analysis
of the SZ and X-ray data, we derive physical properties such as gas mass, total
mass, gas fraction and the intrinsic, integrated Compton y-parameter. We find
that parameters derived from the joint fit to the SZ and X-ray data agree well
with a detailed, independent X-ray-only analysis of the same clusters. In
particular, we find that, when combined with X-ray imaging data, this new
pressure profile yields an independent electron radial temperature profile that
is in good agreement with spectroscopic X-ray measurements.Comment: 28 pages, 6 figures, accepted by ApJ for publication (probably April
2009
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