525 research outputs found
On direct and crossed channel asymptotics of four-point functions in AdS/CFT correspondence
We analyse the leading logarithmic singularities in direct and crossed
channel limit of the four-point functions in dilaton-axion sector of type IIB
supergravity on in AdS/CFT correspondence. Logarithms do not cancel
in the full correlator in both channels.Comment: Revised version, typos corrected, 9 pages, no figure
Stabilization or Exploitation? Cartelization as Institutional Drift in Romania and the Czech Republic
To prevent private interests from distorting the democratic process, most European countries have implemented public funding schemes to guarantee fair competition among political parties. However, very little research has explored the possibility of institutional corruption in conjunction with state political party funding. Katz and Mair’s cartel party thesis argues state support strengthens ties between political parties and the state at the expense of civil society. Oliveira uses organizational theory to point to institutional corruption as a design problem. This paper serves as a preliminary exploration of whether Oliveira’s institutional corruption model and the cartel party theory can be applied to the European context. Comparative case studies of the Czech Republic and Romania, party finance laws and reforms, and the existing cartel party literature in these countries are used to construct a possible new theoretical framework for analysis. Secondary sources such as public opinion polls and surveys are employed to underline the ineffectiveness of political parties’ ability to connect with the electorate. This analysis brings the cartel party thesis and institutional corruption theory together into a single framework, helping to explain how the cartel party thesis can be framed as a problem of organizational design whereby parties drift from their institutional purpose in order to ensure their own survival, losing society’s trust in the process
The Peruvian upwelling ecosystem: dynamics and interactions
Upwelling, Ecosystems, Fishery biology, Fishery oceanography, Conferences, Peru,
Numerical Modeling and Use of Settlement Reducing Auger Cast-In-Place Piles Below a Mat Foundation
The 45-story Great American Tower, the tallest building in Cincinnati, is not only changing the downtown skyline, but is an excellent case study of innovation in geotechnical engineering. This project is an excellent example of the use of technological advances in site characterization and soil-structure methods. When an opportunity arises to combine state-of-the-art concepts with advanced modeling tools, engineers need to combine knowledge and forward thinking to geotechnical solutions to promote the state-of-practice. The Great American Tower at Queen City Square in Cincinnati, Ohio combines a mat foundation with a limited number of auger cast-inplace (ACIP) piles, with the piles primarily acting as settlement reducers. Promoting the unique soil-structure interaction based foundation system required the use of sophisticated numerical modeling tools and seamless communication with the designers, contractor, and owner. Traditional standard penetration test boring data (SPT) was initially used to develop a numerical analysis of the soil-structure interaction using FLAC 3D software. The model was further modified with cone penetration (CPT) and pressuremeter testing (PMT), load test results on several ACIP pile elements of varying lengths, but all tipping above bedrock, and ongoing monitoring. Integrating industry knowledge, with sophisticated modeling techniques, has provided a successful real-world case study
Factors Affecting Bag Silo Densities and Losses
Bag silos (polyethylene tubes, 30 to 90 m length, 2.4 to 3.7 m diameter, 0.22 mm thick) are used on approximately one-third of the dairy farms in the U.S.A. for making silage, and the level of adoption is increasing rapidly. Unfortunately, almost no research data have been published on these types of silos. Our objective was to measure densities and losses in bag silos at three farms, looking for causes of variation in both
Conserved Forage (Silage and Hay): Progress and Priorities
Forage conservation permits a better supply of quality feed when forage production is low. While haymaking and ensiling have been practiced for generations, research is still needed to 1) understand the processes affecting quality during harvesting and storage and 2) develop practical means to minimize losses and enhance quality.
Several trends in harvesting forages for silage are notable. Kernel processing of maize, once confined to Europe, has become popular in North America. Self-propelled forage harvesters have a larger share of the market due to more contract harvesting and larger farms. Larger harvesters, rakes and mergers help improve productivity and forage quality. Finally, farmers are increasing cutting length to meet the fiber needs of high-producing dairy cattle. These latter two trends make good silo management more critical.
The number of silo types has continued to increase. Pressed bag and wrapped bale silages are important recent developments. These newer types have made it easier to segregate silages by quality and allow small farms to make high quality silage. However, disposal of the larger quantities of plastic is a growing issue. Alternatives such as edible or biodegradable films would be welcome for all silo types, reducing labor and environmental concerns. With wrapped bales, spoilage and listeria contamination are more common because of the large surface to volume ratio. Enhanced methods to control spoilage and pathogen development are needed.
With most crops considerable breakdown of true protein occurs during ensiling, subsequently decreasing nitrogen utilization efficiency in ruminants. The polyphenol oxidases in red clover and the tannins in some legumes reduce protein loss during ensiling. These mechanisms may be useful in developing new silage additives or plant varieties.
Additives can enhance silage quality. Inoculants are the most common. Improved inoculants aimed at increasing aerobic stability are beginning to be marketed, but their overall success is uncertain. Enzymes to degrade plant cell walls, providing sugar for fermentation and making the silage more digestible, have not fulfilled their promise but do have potential. Acids and sugars have been declining in use but still are important in certain ensiling situations.
Three types of balers are used to package dry hay: small square (SSB), large round (LRB) and large square balers (LSB). The SSB is declining importance in developed countries because of labor constraints but remains viable in developing countries where farm labor is still plentiful. The LRB is the dominant baler worldwide because of its productivity and low ownership and operating costs. High productivity and a package ideally suited for shipping has promoted the continuing growth of the LSB.
Hay producers struggle with getting crops dry enough (\u3c 20% moisture) to prevent excess storage losses due to biological activity. This is especially important as bale density increases. Typical bale densities are about 130, 190 and 240 kg/m3 for SSB, LRB and LSB, respectively. In humid climates, forage researchers and producers are investigating intensive conditioning systems to improve field drying rates, utilizing preservatives like propionic acid, and developing bale ventilation and drying systems all in the attempt to improve dry hay quality. In arid regions, producers only bale after dew accumulation has softened brittle plant tissue to reduce leaf loss. Systems are under development that will soften plant tissue at the baler by applying a fine water mist. Larger livestock farms and increased development of markets for commercial hay will push demand for greater productivity and better bale quality
Logarithmic conformal field theories and AdS correspondence
We generalize the Maldacena correspondence to the logarithmic conformal field
theories. We study the correspondence between field theories in
(d+1)-dimensional AdS space and the d-dimensional logarithmic conformal field
theories in the boundary of . Using this correspondence, we get the
n-point functions of the corresponding logarithmic conformal field theory in
d-dimensions.Comment: 10 pages, LaTeX. A paragraph was added. To appear in Int. J. Mod.
Phys.
Quarkonium from the Fifth Dimension
Adding fundamental matter of mass m_Q to N=4 Yang Mills theory, we study
quarkonium, and "generalized quarkonium" containing light adjoint particles. At
large 't Hooft coupling the states of spin<=1 are anomalously light (Kruczenski
et al., hep-th/0304032). We examine their form factors, and show these hadrons
are unlike any known in QCD. By a traditional yardstick they appear infinite in
size (as with strings in flat space) but we show that this is a failure of the
yardstick. All of the hadrons are actually of finite size ~ \sqrt{g^2N}/m_Q,
regardless of their radial excitation level and of how many valence adjoint
particles they contain. Certain form factors for spin-1 quarkonia vanish in the
large-g^2N limit; thus these hadrons resemble neither the observed J/Psi
quarkonium states nor rho mesons.Comment: 57 pages, LaTeX, 5 figure
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