969 resultados para Meson-nucleus final state interactions
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We study charmed baryon resonances that are generated dynamically within a unitary meson-baryon coupled-channel model that treats the heavy pseudoscalar and vector mesons on equal footing as required by heavy-quark symmetry. It is an extension of recent SU(4) models with t-channel vector-meson exchanges to an SU(8) spin-flavor scheme, but differs considerably from the SU(4) approach in how the strong breaking of the flavor symmetry is implemented. Some of our dynamically generated states can be readily assigned to recently observed baryon resonances, while others do not have a straightforward identification and require the compilation of more data as well as an extension of the model to d-wave meson-baryon interactions and p-wave coupling in the neglected s- and u-channel diagrams. Of several novelties, we find that the Delta c(2595), which emerged as a ND quasibound state within the SU(4) approaches, becomes predominantly a ND* quasibound state in the present SU(8) scheme.
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Although ab initio calculations of relativistic Brueckner theory lead to large scalar isovector fields in nuclear matter, at present, successful versions of covariant density functional theory neglect the interactions in this channel. A new high-precision density functional DD-MEδ is presented which includes four mesons, σ, ω, δ, and ρ, with density-dependent meson-nucleon couplings. It is based to a large extent on microscopic ab initiocalculations in nuclear matter. Only four of its parameters are determined by adjusting to binding energies and charge radii of finite nuclei. The other parameters, in particular the density dependence of the meson-nucleon vertices, are adjusted to nonrelativistic and relativistic Brueckner calculations of symmetric and asymmetric nuclear matter. The isovector effective mass mp*−mn* derived from relativistic Brueckner theory is used to determine the coupling strength of the δ meson and its density dependence.
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This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.
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This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.
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This book contains information on the dedication ceremony of Iowa monuments on the southern battlefields from the civil war and their final transfer made to the care of the general government. It includes history of the battles, photos and maps.
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Red light running (RLR) is a problem in the US that has resulted in 165,000 injuries and 907 fatalities annually. In Iowa, RLR-related crashes make up 24.5 percent of all crashes and account for 31.7 percent of fatal and major injury crashes at signalized intersections. RLR crashes are a safety concern due to the increased likelihood of injury compared to other types of crashes. One tool used to combat red light running is automated enforcement in the form of RLR cameras. Automated enforcement, while effective, is often controversial. Cedar Rapids, Iowa installed RLR and speeding cameras at seven intersections across the city. The intersections were chosen based on crash rates and whether cameras could feasibly be placed at the intersection approaches. The cameras were placed starting in February 2010 with the last one becoming operational in December 2010. An analysis of the effect of the cameras on safety at these intersections was determined prudent in helping to justify the installation and effectiveness of the cameras. The objective of this research was to assess the safety effectiveness of the RLR program that has been implemented in Cedar Rapids. This was accomplished by analyzing data to determine changes in the following metrics: Reductions in red light violation rates based on overall changes, time of day changes, and changes by lane Effectiveness of the cameras over time Time in which those running the red light enter the intersection Changes in the average headway between vehicles entering the intersection
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We have studied the adsorption process of non-Brownian particles on a line. Our work differs from previously proposed models in that we have incorporated hydrodynamic interactions between the incoming particles and the preadsorbed particles as well as the surface. We then numerically analyze the effect of these interactions on quantities related to the adsorption process. Comparing our model to the ballistic deposition model (BM) shows a significant discrepancy in the pair correlation function. These results can explain some differences between recent experiments and BM predictions. Finally, the limitations of the applicability of BM are addressed.
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We propose a procedure for analyzing and characterizing complex networks. We apply this to the social network as constructed from email communications within a medium sized university with about 1700 employees. Email networks provide an accurate and nonintrusive description of the flow of information within human organizations. Our results reveal the self-organization of the network into a state where the distribution of community sizes is self-similar. This suggests that a universal mechanism, responsible for emergence of scaling in other self-organized complex systems, as, for instance, river networks, could also be the underlying driving force in the formation and evolution of social networks.
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Atribution as a function of the time are analyzed and this study leads to a deeper knowledge of the microscopic processes involved in the magnetic relaxation
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Steady-state blood concentrations of (R)- methadone (i.e., the active form), (S)-methadone, and (R,S)-methadone were measured before and after introduction of paroxetine 20 mg/day during a mean period of 12 days in 10 addict patients in methadone maintenance treatment. Eight patients were genotyped as CYP2D6 homozygous extensive metabolizers (EMs) and two patients as poor metabolizers (PMs). Paroxetine significantly increased concentrations of both enantiomers of methadone in the whole group (mean increase for (R)-methadone +/- SD, 26 +/- 32%; range, -14% to +83%, p = 0.032; for (S)-methadone, 49 +/- 51%; range, -29% to +137%, p = 0.028; for (R,S)-methadone, 35 +/- 41%; range, -20% to +112%, p = 0.032) and in the group of eight EMs (mean increase, 32%, p = 0.036; 53%, p = 0.028; and 42%, p = 0.036, for (R)-methadone, (S)-methadone, and (R,S)-methadone, respectively). On the other hand, in the two PMs, (S)-methadone but not (R)-methadone concentrations were increased by paroxetine (mean increases of 36% and 3%, respectively). Paroxetine is a strong CYP2D6 inhibitor, and these results confirm previous studies showing an involvement of CYP2D6 in methadone metabolism with a stereoselectivity toward the (R)-enantiomer. Because paroxetine is a mild inhibitor of CYP1A2, CYP2C9, CYP2C19, and CYP3A4, increase of (S)-methadone concentrations in both EMs and PMs could be mediated by inhibition of any of these isozymes.
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Debris accumulation on bridge piers is an on-going national problem that can obstruct the waterway openings at bridges and result in significant erosion of stream banks and scour at abutments and piers. In some cases, the accumulation of debris can adversely affect the operation of the waterway opening or cause failure of the structure. In addition, removal of debris accumulation is difficult, time consuming, and expensive for maintenance programs. This research involves a literature search of publications, products, and pier design recommendations that provide a cost effective method to mitigate debris accumulation at bridges. In addition, a nationwide survey was conducted to determine the state-of-the-practice and the results are presented within.
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The quality and availability of aggregate for pc concrete stone varies across Iowa. Southwest Iowa is one area of the state that is short of quality aggregates. The concrete stone generally available in the area is limestone from the Argentine or Winterset ledges with an overburden of up to 150 feet. This concrete stone is classified as Class 1 durability and is susceptible to 'ID"-cracking. In addition, the general engineering soil classification rates the soils of southwest Iowa as having the poorest subgrade bearing characteristics in the state. 1 The combination of poor soils and low quality aggregate has contributed to premature deterioration of many miles of portland cement concrete pavement. Research project HR-209 was initiated in 1979 to explore alternative construction methods that may produce better pavements for southwest Iowa.
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Safety i s a very important aspect o f the highway program. The Iowa DOT initiated an inventory o f the friction values of all paved primary roadways i n 1969. This inventory, with an ASTM E-274 test unit, has continued to the present time. The t e s t i n g frequency varies based upon traffic volume and the previous friction value. Historically , the state o f Iowa constructed a substantial amount o f pcc pavement during the 1928-30 period t o "get Iowa out o f the mud". Some of that pavement has never been resurfaced and has been subjected to more than 50 years o f wear. The textured surface has been worn away and has subsequently polished. Even though some pavements from 15 t o 50 years old continue t o function structurally , because of the loss of friction , they do not provide the desired level o f safety to the driver. As a temporary measure, "Sl ippery -When -Wet " signs have been posted on many older pcc roads due to friction numbers below t h e desirable level. These signs warn the motorist of the current conditions. An economical method of restoring the high quality frictional properties i s needed.
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With the spiraling cost of construction, coupled with inflation, engineers must develop and research new techniques to better utilize the public's dollar. One area i n which these new technologies must be researched is in the field of highway construction; more specifically, asphalt products. There are areas within the state of Iowa which do not have Class I aggregate readily available for asphalt concrete road construction. The cost of transporting higher quality aggregate specified in the "Standard Specifications for Highway and Bridge construction"' for construction projects is escalating on a yearly basis. Many counties will be squeezed out of the construction of new roadways if an alternative to the high costs is not identified. The same high costs will curtail adequate upkeep on the existing paved system and will result in decreased serviceability. For this reason, a product is needed to better utilize the local aggregates for road construction and maintenance. There i s a product on the market which the promoters claim will improve the prer?nt asphalt to such a degree as to "upgrade deficient aggregates" to the level they can be used in today's standard construction techniques. This product is "Chem-Crete Bitumen," a'kpecially refined asphalt" that was promoted by Chem-Crete Corporation of Menlo Park, California. Chemkrete Technologies, Inc. of Wickliffe, Ohio; a wholly owned subsidiary of the Lubrizol Corporation has since purchased the U.S.