999 resultados para post-receptoral


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Using U.S. interest rate data covering the period 1950:1-1992:7, this paper tests the rational expectations model of the term structure of interest rates. We show evidence that the rational expectations model of the term structure is supported by the data during the seventies and a period lasting from the mid-eighties to the end of the sample. However, during the …fties, sixties and a period that covers most of the Volcker’s office term (from September 1979 to April 1986) the term structure model is rejected by the data. Moreover, wefind evidence of regime changes in the short-term rate process and the term structure of interest rates. These regime switches roughly coincide with changes in the Federal Reserve chairman. The switches in monetary policy taking place when the chairmanship of the Federal Reserve changes therefore seem to play an important role in characterizing the term structure of interest rates.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Published as an article in: Studies in Nonlinear Dynamics & Econometrics, 2004, vol. 8, issue 1, pages 5.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study presents the third post-nourishment survey (January 1989) results for the Sand Key Phase II beach nourishment project carried out in June, 1988. The monitoring program to this beach nourishment project is a joint effort between the University of South Florida and University of Florida. The field surveys include a total of 26 profiles, encompassing approximately 3 miles of shoreline extending from DNR R-96 to R-1ll. The total calculated volume loss of sand in the nourished segment (from R-99G to R-107) between the July 88 and January 89 surveys is 51,113 cubic yards, which is a loss about 9.7 percent of 529,150 cubic yards actually placed in the nourishment project. The total loss of sand computed in the entire survey area is 26,796 cubic yards, which is only 5.1 percent of the sand placed in the nourishment project. It is stressed that a part of these net volume reductions is due to the background erosion and not due to spreading losses induced by the nourishment project. (PDF contains 168 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Whole-lake techniques are increasingly being used to selectively remove exotic plants, including Eurasian watermilfoil ( Myriophyllum spicatum L.). Fluridone (1-methyl-3-phenyl- 5-[3-(trifluoromethyl)phenyl]-4(1 H )-pyridinone), a systemic whole-lake herbicide, is selective for Eurasian watermilfoil within a narrow low concentration range. Because fluridone applications have the potential for large effects on plant assemblages and lake food webs, they should be evaluated at the whole-lake scale. We examined effects of low-dose (5 to 8 ppb) fluridone applications by comparing submersed plant assemblages, water quality and largemouth bass ( Micropterus salmoides ) growth rates and diets between three reference lakes and three treatment lakes one- and two-years post treatment. In the treatment lakes, fluridone reduced Eurasian watermilfoil cover without reducing native plant cover, although the duration of Eurasian watermilfoil reduction varied among treatment lakes. (PDF has 11 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[ES]Este trabajo se centra en el análisis de la relación entre las políticas crediticias de las entidades de crédito y el comportamiento de las mismas ex post. Se hace una revisión de la teoría que justifica que los mercados crediticios pueden estar sujetos, en determinadas circunstancias, a un componente endógeno más elevado de lo que, en general, se atribuye. Se plantea como hipótesis de trabajo la existencia de una relación entre la intensidad en el crecimiento de la cartera crediticia de los bancos en las fases de expansión crediticia y su comportamiento ex post. Los resultados preliminares presentados confirman la hipótesis de que las entidades que más desvían su crecimiento crediticio respecto del crecimiento del PIB nominal, están sujetas a un peor comportamiento en cuanto a la evolución posterior de sus beneficios, rentabilidades e insolvencias.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

© Este trabajo está licenciado bajo la licencia Creative Commons Attribution 3.0.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Proiektu honetan zehar Itzulpen Automatikoa eta horren inguruko tresnen inguruan jorratu da. Lengoaia Naturalaren Prozesamendua eta itzulpen automatikoa ikasi eta aztertu egin dira ikuspuntu zabal batetik. Itzulpen automatiko orokorraz eta horren aplikazio mota desberdinetatik gain, bestelako kontzeptuak ere tratatu dira, hala nola, itzulpenean laguntzeko tresnak, itzulpen automatikoaren ebaluazioa eta itzulpen automatikorako testuen aurre-edizioa eta post-edizioa. Ikasketa- eta aztertze-prozesu horretaz gain, erlazionatuta dauden tresnak erabili edota moldatu egin dira euskararako itzulpen automatikoan barne. Hiru atal nagusi nabarmendu daitezke: Lehenengo, OmegaT, itzulpenean laguntzeko softwarea, moldatu da Matxin euskararako itzultzaile automatikoa gehituz. Gainera, IXA Taldearen eta Euskal Wikipediaren arteko kolaborazio-lanean, Wikipediako artikuluak eskuratu, itzuli eta igotzeko aukera egokitu zaio OmegaT-ri eta horren erabilera sustatu da Euskal Wikipediako komunitatean eta UPV/EHUko Informatikako ikasle eta irakaslegoaren artean. Bestalde, lan honetaz baliatuz, OmegaT-k sortzen dituen itzulpen-memoriak, Matxin-en itzulpenen gaineko post-edizioan oinarrituak, eskuratzeko modu bat egin da, horiekin Matxin-en funtzionamendua hobetu ahal izateko. Ondoren, Asiya programan integratu egin da euskara. Asiya-k itzulpen automatikoaren ebaluazio eta meta-ebaluazioak egin ditzakeen aplikazioa da. Hainbat metrika aztertu dira euskara aztertzeko balio ote duten begiratzeko. Besteen artean, lau metrikari euskara gehitzeko saiakera egin nahi izan da IXA Taldeko euskarazko testuen analizatzaile batek eskainitako informazio sintaktikoa gehituz, baina bi metrika soilik egokitu ahal izan dira. Azkenik, DiSeg esaldi-segmentatzailea erabili egin da gaztelerazko corpus baten gainean esaldi luzeak banatzeko. Aurre-edizio hori eta gero itzuli egin dira eta Asiya erabiliz emaitzen ebaluazioa eta konparazioa egin dira, esaldi laburragoekin itzulpen automatiko eraginkorragoa lortzen oten den aztertzeko.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A series of static and cyclic-static tri-axial compression tests under consolidated-undrained conditions are carried out to study the characteristics of post-cyclic strength of the undisturbed and the remolded samples of marine silty clay. It is found that the post-cyclic monotonic strength decreases if the cyclic strain or pore pressure is over a certain value. The maximum degradation is 10% for undisturbed samples while 70% for remolded ones. The relationship between normalized undrained shear strength and apparent overconsolidation ratio, which is determined by the excess pore pressure induced by cyclic loading, is also established. Static consolidated-undrained tests on overconsolidated remolded samples are also performed. It is proposed that the static consolidated-undrained tests may be substituted for the cyclic-static consolidated-undrained tests if the post-cyclic strength degradation of remolded silty clay is needed to be evaluated simply.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Instrumental investigations of texture have been performed using texture profile analysis. The following textural parameters have been assessed: hardness, gumminess, chewiness, springiness, cohesiveness and adhesiveness. The fillets of both species have been prepared from deep frozen headed and gutted raw material without fins after frozen storage of 0, 23 and 34 weeks, respectively. Deep freezing of fishes has been performed on board immediately after hauling or after 6 day’s storage in ice. Before texture measurement the raw material has been thawed and the measurement was carriedout on both thawed and microwave-heated fillets. In general, it can be concluded that both fish species are comparable in their texture parameters. The hardness of heated dab has been slightly higher comparing with that one of plaice. All other texture parameters showed a fairly good conformity between both species. While the hardness of dab increased during heating, it was decreasing in plaice. This was the only one significant difference between both fishes during heating. Adhesiveness as well as cohesiveness increased remarkably during heating. Changes effected by ice storage were only slight. Frozen storage, in contrast, caused a significant decrease of adhesiveness measured after heating the fillets of both species.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The findings are presented of a study undertaken to provide baseline information that may be employed to develop a simplified hatchery technique for postlarval feeding of Clarias gariepinus on zooplankton cultured indoors in small aquaria. Three series of experiments were undertaken to identify the type and quantity of organic manure that would produce maximum densities of zooplankton in the shortest time in indoor cultures. Results suggest the possibility of the culture of natural zooplankton populations for use in larval feeding of C. gariepinus fry. Its effective hatchery application would bring about reduction in the unit cost per fingerling and ensure continuous hatchery operations even in the absence of Artemia cysts

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper provides a description of a methodology used for quantitative assessment of post harvest losses in the Kainji Lake Fishery (Nigeria). The sample population was made up of 314 fisherfolk, 115 processors, 125 fish buyers and 111 fish sellers. For the determination of handling losses, 24,839 fishes weighing 2,389.31 kg belonging to 43 species were examined of which 10% by number and 9% by weight deteriorated at checking and 4% by number and 3% by weight at landing. Processing losses recorded 22% by number and 16% by weight deteriorated prior to and during smoking with the traditional 'Banda' kiln. During marketing, 16% of fish sold had deteriorated and 6% by weight of fish bought also deteriorated, mainly due to insect infestation during storage. Based on the 1995 yield estimate for Kainji Lake fishery, approximately 1000 tons of fish estimated at 80 million Naira were lost during handling alone. This figure would be much higher if the level of losses during processing and marketing are included. This assessment technique is recommended for use in obtaining quantifiable data on post harvest losses from other water bodies in Nigeria

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The findings are presented of a study conducted to assess the post harvest losses in Shiroro Lake, Nigeria. The major objectives were to identify and quantify the types of losses, to provide recommendations that would enhance formulation of policy guidelines for utilization and exploitation of the declining fishery resources of the lake

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An assessment is given of the post-harvest losses in the Lake Kainji fisheries of Nigeria. The study focussed on quantifiable information on post-harvest technology and post-harvest losses from fisherfolk, fish processors and fish traders operating within the Kainji Lake basin. The information was obtained from questionnaires sent to a total of 665 respondents, comprising 317 fishermen, 115 fish processors, 125 fish buyers, and 111 fish sellers in 45 fishing villages and collection centres within the lake basin. Considering the total catch from gillnets, longlines, traps and cast nets estimated at 14,000 in 1995 about 1,000 t of fish was either discarded or lost value due to spoilage during handling by fisherfolk. Assuming an average prices of 80 Naira/kg of fish, the loss to the economy amounted to 80 million Naira annually. Appropriate recommendations are made to significantly reduce post-harvest losses in the Kainji Lake fishery. (PDF contains 91 pages)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A long-standing challenge in transition metal catalysis is selective C–C bond coupling of simple feedstocks, such as carbon monoxide, ethylene or propylene, to yield value-added products. This work describes efforts toward selective C–C bond formation using early- and late-transition metals, which may have important implications for the production of fuels and plastics, as well as many other commodity chemicals.

The industrial Fischer-Tropsch (F-T) process converts synthesis gas (syngas, a mixture of CO + H2) into a complex mixture of hydrocarbons and oxygenates. Well-defined homogeneous catalysts for F-T may provide greater product selectivity for fuel-range liquid hydrocarbons compared to traditional heterogeneous catalysts. The first part of this work involved the preparation of late-transition metal complexes for use in syngas conversion. We investigated C–C bond forming reactions via carbene coupling using bis(carbene)platinum(II) compounds, which are models for putative metal–carbene intermediates in F-T chemistry. It was found that C–C bond formation could be induced by either (1) chemical reduction of or (2) exogenous phosphine coordination to the platinum(II) starting complexes. These two mild methods afforded different products, constitutional isomers, suggesting that at least two different mechanisms are possible for C–C bond formation from carbene intermediates. These results are encouraging for the development of a multicomponent homogeneous catalysis system for the generation of higher hydrocarbons.

A second avenue of research focused on the design and synthesis of post-metallocene catalysts for olefin polymerization. The polymerization chemistry of a new class of group 4 complexes supported by asymmetric anilide(pyridine)phenolate (NNO) pincer ligands was explored. Unlike typical early transition metal polymerization catalysts, NNO-ligated catalysts produce nearly regiorandom polypropylene, with as many as 30-40 mol % of insertions being 2,1-inserted (versus 1,2-inserted), compared to <1 mol % in most metallocene systems. A survey of model Ti polymerization catalysts suggests that catalyst modification pathways that could affect regioselectivity, such as C–H activation of the anilide ring, cleavage of the amine R-group, or monomer insertion into metal–ligand bonds are unlikely. A parallel investigation of a Ti–amido(pyridine)phenolate polymerization catalyst, which features a five- rather than a six-membered Ti–N chelate ring, but maintained a dianionic NNO motif, revealed that simply maintaining this motif was not enough to produce regioirregular polypropylene; in fact, these experiments seem to indicate that only an intact anilide(pyridine)phenolate ligated-complex will lead to regioirregular polypropylene. As yet, the underlying causes for the unique regioselectivity of anilide(pyridine)phenolate polymerization catalysts remains unknown. Further exploration of NNO-ligated polymerization catalysts could lead to the controlled synthesis of new types of polymer architectures.

Finally, we investigated the reactivity of a known Ti–phenoxy(imine) (Ti-FI) catalyst that has been shown to be very active for ethylene homotrimerization in an effort to upgrade simple feedstocks to liquid hydrocarbon fuels through co-oligomerization of heavy and light olefins. We demonstrated that the Ti-FI catalyst can homo-oligomerize 1-hexene to C12 and C18 alkenes through olefin dimerization and trimerization, respectively. Future work will include kinetic studies to determine monomer selectivity by investigating the relative rates of insertion of light olefins (e.g., ethylene) vs. higher α-olefins, as well as a more detailed mechanistic study of olefin trimerization. Our ultimate goal is to exploit this catalyst in a multi-catalyst system for conversion of simple alkenes into hydrocarbon fuels.