5,180 research outputs found
Boundary Yang-Baxter equation in the RSOS representation
The boundary Yang-Baxter equation in the RSOS representation is found to posses two classes of trigonometric solution; diagonal and off-diagonal. The diagonal solution is not a special limit of the off-diagonal one and is unique to the RSOS representation as it contains p-3 parameters where p-1 is the number of allowed height. The corresponding commuting transfer matrix is also constructed
ECONOMIC FEASIBILITY OF THE CATTLE FEEDING INDUSTRY IN THE NORTHERN PLAINS AND WESTERN LAKES STATES - SUMMARY
The five-state study area of the Northern Plains and Western Lakes States, Minnesota, Montana, North Dakota, South Dakota, and Wisconsin, has adequate feed supplies and feeder cattle to markedly increase cattle feeding. Feed costs in these states have historically been lower than in the Southern Plains States. However, higher transportation costs appear to offset that advantage. Close access to slaughter plants in these states could offset that transportation disadvantage. Backgrounding of cattle appears to be quite profitable and cattle feeding, especially in larger sized feedlots, can be profitable. However, the cattle feeding industry has an increasing level of excess capacity. To be successful, new feedlots in the Northern Plains and Western Lakes States would need cost efficiencies to offset higher production costs, compared to Nebraska and Kansas, or would need to produce for a niche market unaffected by the lower operating costs of already established feedlots in the Central and Southern Plains States. Finally, a range of strategies are available in developing value-added cattle production in the Northern Plains and Western Lakes States. These strategies embody differing levels of capital investment, and involve different levels of risk and profitability.cattle feeding, Northern Plains, economies of scale, cooperative ownership, entrance strategies, Production Economics,
The Safety of Systemic Treatments That Can Be Used for Geriatric Psoriasis Patients: A Review
Background. Patients with moderate-to-severe psoriasis are often treated with systemic immunosuppressant agents that decrease immune system function. For the elderly, these medications are often problematic due to their already immunosuppressed state and comorbidities. However, there are few studies examining the effects of these medications on the elderly age group. Therefore, there is often discomfort among dermatologists treating elderly patients with psoriasis in utilizing systemic agents, frequently resulting in inadequate treatment. Objective. We review the safety profiles of systemic treatments often used to treat psoriasis and their possible adverse risks to the geriatric population. Methods. We conducted a search of PubMed's Medline database of articles published from 2000 to 2011, which resulted in 14 articles. Conclusion. Treating geriatric patients with moderate-to-severe psoriasis remains a challenge due to immunosenescence and comorbidities. More studies focusing on psoriasis treatment safety in the geriatric population are needed
An ASCA Study of the W51 Complex
We present the analysis of ASCA archival data from the Galactic source W51.
The ASCA spectra show that the soft (kT<= 2.5 keV) X-rays are of thermal origin
and are compatible with W51C being a single, isothermal (kT~0.3 keV) supernova
remnant at the far-side of the Sagittarius arm. The ASCA images reveal hard
(kT>=2.5 keV) X-ray sources which were not seen in previous X-ray observations.
Some of these sources are coincident with massive star-forming regions and the
spectra are used to derive X-ray parameters. By comparing the X-ray absorbing
column density with atomic hydrogen column density, we infer the location of
star-forming regions relative to molecular clouds. There are unidentified hard
X-ray sources superposed on the supernova remnant and we discuss the
possibility of their association.Comment: 13 pages, 11 figures, to be published in Astronomical Journa
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Innovative Selective Laser Sintering Rapid Manufacturing using Nanotechnology
The objective of this research is to develop an improved nylon 11 (polyamide 11) polymer
with enhanced flame retardancy, thermal, and mechanical properties for selective laser sintering
(SLS) rapid manufacturing (RM). A nanophase was introduced into nylon 11 via twin screw
extrusion to provide improved material properties of the polymer blends. Atofina (now known
as Arkema) RILSAN® nylon 11 injection molding polymer pellets was used with three types of
nanoparticles: chemically modified montmorillonite (MMT) organoclays, nanosilica, and carbon
nanofibers (CNF) to create nylon 11 nanocomposites. Wide angle X-ray diffraction (WAXD)
and transmission electron microscopy (TEM) were used to determine the degree of dispersion.
Fifteen nylon 11 nanocomposites and control nylon 11 were fabricated by injection molding.
Flammability properties (using a cone calorimeter with a radiant flux of 50 kW/m2
) and
mechanical properties such as tensile strength and modulus, flexural modulus, elongation at
break were determined for the nylon 11 nanocomposites and compared with the baseline nylon
11. Based on flammability and mechanical material performance, five polymers including four
nylon 11 nanocomposites and a control nylon 11 were cryogenically ground into fine powders
for SLS RM. SLS specimens were fabricated for flammability, mechanical, and thermal
properties characterization. Nylon 11-CNF nanocomposites exhibited the best overall properties
for this study.Mechanical Engineerin
OH (1720 MHz) Masers: A Multiwavelength Study of the Interaction between the W51C Supernova Remnant and the W51B Star Forming Region
We present a comprehensive view of the W51B HII region complex and the W51C
supernova remnant (SNR) using new radio observations from the VLA, VLBA,
MERLIN, JCMT, and CSO along with archival data from Spitzer, ROSAT, ASCA, and
Chandra. Our VLA data include the first 400 cm (74 MHz) continuum image of W51
at high resolution (88 arcsec). The 400 cm image shows non-thermal emission
surrounding the G49.2-0.3 HII region, and a compact source of non-thermal
emission (W51B_NT) coincident with the previously-identified OH (1720 MHz)
maser spots, non-thermal 21 and 90 cm emission, and a hard X-ray source.
W51B_NT falls within the region of high likelihood for the position of TeV
gamma-ray emission. Using the VLBA three OH (1720 MHz) maser spots are detected
in the vicinity of W51B_NT with sizes of 60 to 300 AU and Zeeman effect
magnetic field strengths of 1.5 to 2.2 mG. The multiwavelength data demonstrate
that the northern end of the W51B HII region complex has been partly enveloped
by the advancing W51C SNR and this interaction explains the presence of W51B_NT
and the OH masers. This interaction also appears in the thermal molecular gas
which partially encircles W51B_NT and exhibits narrow pre-shock (DeltaV 5 km/s)
and broad post-shock (DeltaV 20 km/s) velocity components. RADEX radiative
transfer modeling of these two components yield physical conditions consistent
with the passage of a non-dissociative C-type shock. Confirmation of the
W51B/W51C interaction provides additional evidence in favor of this region
being one of the best candidates for hadronic particle acceleration known thus
far.Comment: Accepted to Ap
Gaussian Effective Potential and the Coleman's normal-ordering Prescription : the Functional Integral Formalism
For a class of system, the potential of whose Bosonic Hamiltonian has a
Fourier representation in the sense of tempered distributions, we calculate the
Gaussian effective potential within the framework of functional integral
formalism. We show that the Coleman's normal-ordering prescription can be
formally generalized to the functional integral formalism.Comment: 6 pages, revtex; With derivation details and an example added. To
appear in J. Phys.
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