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Roles of Naturally Occurring Bacteria in Controlling Iodine-129 Mobility in Subsurface SoilsLi, Hsiu-Ping 2012 August 1900 (has links)
129I is of major concern because of its biophilic nature, excessive inventory, long half-life (~16 million yrs), and high mobility in the natural environment that depends on its chemical speciation. Iodide (I-) has the highest mobility than iodate (IO3-) and is the predominant species in the terrestrial environment due to prevailing pH and Eh conditions. In order to transform I- to less mobile organo-iodine (OI), strong oxidants are necessary to activate the first electron transfer step from I- to reactive intermediates. The aim of this study was to determine the influence of naturally occurring aerobic bacteria isolated from an 129I contaminated aquifer (F-area of the Savannah River Site, SC) on I- oxidation and OI formation.
It was demonstrated that 3 of 136 strains accumulated I- (0.2~2%) in the presence of H2O2, when incubated in the presence of an environmentally relevant concentration of I- (0.1 microM). The accumulation was likely through electrophilic substitution resulting in the iodination of cellular constituents. The results indicated that culturable I--accumulating bacteria are not directly responsible for the high fraction of oxidized iodine species (IO3- and OI, >50% of total I) present in the SRS F-area.
Several bacterial strains were found to be capable of stimulating I- oxidation through excretion of oxidants and enzymes. Organic acids in spent liquid medium from 27 of 84 aerobic bacterial cultures enhanced H2O2-dependent I- oxidation 2-10 fold. Organic acids enhanced I- oxidation by (1) lowering the pH of the spent medium and (2) reacting with H2O2 to form peroxy carboxylic acids, which are strong oxidizing agents.
In the absence of H2O2, spent medium from 44 of 84 bacteria cultures showed I- oxidizing capacities. One I- oxidizing bacterium was studied to characterize its extracellular I- oxidizing component(s). The I- oxidizing capability from the spent medium was inactive by treatments with heat and H2O2 and absent under anaerobic conditions. Conversely, NADH, NADPH and FMN additions stimulated I- oxidation in the spend medium. These results indicate an oxidase(s) catalyzed I- oxidation. Understanding the bacterial activities involved with I- oxidation and OI formation is expected to help reduce 129I mobility in water-soil systems.
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Preventing rapid platelet accumulation under very high shear stressPara, Andrea N. 21 May 2012 (has links)
Atherosclerosis is a major cause of mortality in industrialized nations. Atherosclerosis is characterized by plaque deposition which decreases the lumen diameter into a stenosis. The creation of a restriction increases shear rates pathologic levels exceeding 3,500/s. Following plaque cap rupture, thrombus may form from the accumulation of millions of platelets, occluding the vessel, leading to heart attack and stroke. Studies of high shear thrombosis show that platelet activation, GPIIb/IIIa and vWF are involved. However, some recent studies also suggest that high shear aggregation is not dependent on activation or GPIIb/IIIa. Several antiplatelet pharmaceuticals against activation
and GPIIb/IIIa have been proposed, but their efficacy in patients remains mixed. The overall
objective of this project is to determine the factors necessary for thrombosis to occlusion in very high shear regions seen in diseased arteries. Our central hypotheses are that platelet activation and the subsequent conformational change in GPIIb/IIIa are
necessary for thrombosis, and that higher concentrations of vWF in the plasma will
increase thrombosis.
To this end, we developed a new high shear hemodynamic model utilizing 30mLs of whole blood and quantified thrombus thickness, volume accumulation and accumulation rates. We demonstrate that thrombosis to occlusion stems from a second phase of Rapid Platelet Accumulation (RPA). Thrombus accumulation is completely prevented by PGE1 inhibition of platelet activation. Similarly, GPIIb/IIIa blockade via abciximab prevented significant thrombus deposition and RPA. We also found that
increasing plasma vWF levels in high shear regions increased thrombus thickness and
suggestively increased RPA rates. The results clarify the need for activation of mural
platelets for long term thrombus accumulation without the activation of circulating platelets.
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Fatigue Life Assessment of 30CrNiMo8HH Steel Under Variable Amplitude LoadingIbrahim, Elfaitori January 2012 (has links)
The actual service loading histories of most engineering components are characterized by variable amplitudes and are sometimes rather complicated. The goal of this study was to estimate the fatigue life of nickel-chromium-molybdenum 30CrNiMo8HH steel alloy under axial and pure torsion variable amplitude loading (VAL) conditions. The investigation was directed at two primary factors that are believed to have an influence on fatigue life under such loading conditions: load sequence and mean stress. The experimental work for this research included two-step loading, non-zero mean strain loading, and VAL tests, the results of which were added to previously determined fully reversed strain-controlled fatigue data. The effect of load sequence on fatigue life was examined through the application of the commonly used linear damage accumulation rule along with the Manson and Marco–Starkey damage accumulation methods, the latter of which takes load sequence into account. Based on the two-step experimental results, both the Manson and Marco–Starkey methods were modified in order to eliminate the empirically determined constants normally required for these two methods. The effect of mean stress on fatigue life was investigated with the use of three life prediction models: Smith–Watson–Topper (SWT), Fatemi–Socie (FS), and Jahed–Varvani (JV). The cycles from the VAL histories were counted using a rainflow counting procedure that maintains the applied strain sequence, and a novel method was developed for the estimation of the total energy density required for the JV model. For two-step loading and for all three fatigue models employed, the modified damage accumulation methods provided superior fatigue life predictions. However, regardless of the damage accumulation method applied, the most satisfactory fatigue life correlation for VAL was obtained using the energy-based JV model.
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Influence of deep-seated structure on hydrocarbon accumulations in the Cooper and Eromanga BasinsBoucher , Rodney January 2005 (has links)
The primary objective of this study is to provide a greater understanding of the tectonic evolution of the Warburton, Cooper, Eromanga and Lake Eyre Basins in central Australia. However, this study additionally attempts to provide a greater understanding of lineaments. This study compares lineament data with a traditional tectonic analysis in order to evaluate lineaments and to best understand the tectonic evolution of the region.
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The Renminbi Challenge: Is a Revaluation of the Chinese Currency a Wise Step Forward?Stein, Christine January 2007 (has links)
<p>The aim of this paper is to investigate if a revaluation of the Chinese renminbi is in China’s interest and whether or not a renminbi revaluation can contribute to correct the US current account deficit. For that purpose, advantages and disadvantages of a revaluation for China are discussed. Furthermore, the fundamental causes of the US current account deficit are analysed to evaluate to what extent a renminbi revaluation can correct this imbalance. The discussion is based on previous research in this area. The main result is that a revaluation of the Chinese renminbi is primarily beneficial for China. Additionally it is found that the fundamental causes of the US current account deficit are domestic macroeconomic conditions and not China’s exchange rate policy. Nevertheless, a renminbi revaluation can help to support to correct the imbalance situation. As evidence is found that a revaluation is beneficial for China, it is further analysed how the revaluation should be practically obtained. The basic result is that the renminbi revaluation should be initiated by more exchange rate flexibility rather than by a one-step appreciation.</p>
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Evaluation of the distribution and accumulation of species of Alicyclobacillus in the fruit concentrate processing environmentSteyn, Catharina Elizabeth 03 1900 (has links)
Thesis (MSc Food Sc (Food Science))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: Alicyclobacillus species are thermo-acidophilic bacteria that produce highly resistant
endospores able to survive the processing temperatures of fruit concentrate
manufacturing, including evaporation and conventional pasteurisation (86 ° - 96 °C for
± 2 min). Alicyclobacillus endospores retain their viability in juice concentrates which,
under favourable conditions, could germinate and multiply to numbers high enough to
cause spoilage and product deterioration through the production of chemical taint
compounds. This thesis reports on the distribution of Alicyclobacillus in the fruit
concentrate processing environment and the effect of current manufacturing practices
on the accumulation of Alicyclobacillus in fruit concentrates. These practices include
the recirculation (recycling) of flume water as a means of water conservation, as well as
continuous process running times when facilities operate at full capacity. This thesis
also reports on the effect of fruit variety and skin type on the occurrence of
Alicyclobacillus in fruit concentrates.
Alicyclobacillus was monitored at nine processing stages of fruit concentrate
manufacturing during the functioning of either a recirculating or a one-pass
(not recirculated) flume water system. Significantly higher Alicyclobacillus levels were
recovered in fruit mash, single strength juice, concentrate and the final pasteurised
product (± 30 °Brix) during the functioning of a re circulating flume system, compared to
when a one-pass flume system was functional (P < 0.05). Irrespective of the flume
system, high Alicyclobacillus levels were recovered from the concentrate and
condensate water (a by-product of juice concentration) from the evaporator, which
makes this a point of concern during concentrate manufacturing. Manufacturing
practices such as the recirculation of flume water and the recovery of condensate water
for fruit washing purposes pose a potential risk of Alicyclobacillus contamination and
accumulation in fruit concentrates and the processing environment.
The effect of continuous process running times on Alicyclobacillus was monitored
in a facility that was operating at full capacity. Sampling occurred every 12 h at four
processing stages, during a processing tempo of 1.8 - 2.0 t h-1 for 108 h. Vegetative
cells increased significantly (P < 0.05) in single strength juice and condensate water
after 84 h of processing, with 3.15 and 3.85 log10 cfu mL-1 recovered, respectively.
Similar accumulation patterns of vegetative cells were observed in concentrate and the
final pasteurised product. Endospores in single strength juice, concentrate and the final
product were also the highest after 84 h of processing with 1.32, 1.59 and
1.64 log10 cfu mL-1, respectively. When fruit concentrate manufacturing facilities
process at full capacity, a restriction in the continuous process running time to under
84 h in between CIP procedures, along with good manufacturing practices, can
minimise Alicyclobacillus accumulation in fruit concentrates.
The effect of fruit skin type, specifically hairy-skinned stone fruits (peach and
apricot) and smooth-skinned pome fruits (apple and pear) on the occurrence of
Alicyclobacillus in concentrates were examined. Apple concentrate samples had the
highest occurrence (average %) of vegetative Alicyclobacillus cells (50%), followed by
apricot (40%), peach (15%) and pear (10%) concentrates. The occurrence of
Alicyclobacillus endospores in fruit concentrate samples were also the highest in apple
(50%), followed by pear (25%), apricot (20%), and peach (10%) concentrates. The
occurrence of Alicyclobacillus vegetative cells and endospores did not differ significantly
(P > 0.05) between concentrates from hairy-skin and smooth-skin fruit varieties. Thus it
was concluded that fruit washing steps prior to processing was more critical for the
control of Alicyclobacillus than the type of fruit skin being processed. / AFRIKAANSE OPSOMMING: Alicyclobacillus spesies is termo-asidofiliese bakterieë wat hoogs bestande endospore
produseer met die vermoë om prosesseringstemperature, insluitend verdamping en
konvensionele pasteurisasie temperature (86 ° - 96 °C vir ± 2 min), tydens die
vervaardiging van vrugtekonsentraat te oorleef. Alicyclobacillus endospore behou hul
lewensvatbaarheid in vrugtekonsentrate en kan in gunstige toestande ontkiem en
vermeerder tot getalle wat wansmake in produkte kan veroorsaak weens die produksie
van chemiese verbindings. Hierdie tesis doen verslag oor die verspreiding van
Alicyclobacillus in die vrugtekosentraat prosesseringsomgewing en oor die effek van
huidige produksie praktyke op die akkumulasie van Alicyclobacillus in
vrugtekonsentrate. Die praktyke sluit in, die hersirkulering van leigeut (transport) water
as ‘n wyse van waterbesparing, asook aaneenlopende prosesseringstye wanneer
vrugtekosentraat fabrieke teen ‘n volle kapasiteit prosesseer. Daar word ook verslag
gedoen oor die effek van verskillende vrug variëteite en vel tipes op die voorkoms van
Alicyclobacillus in vrugtekonsentrate.
Alicyclobacillus was gemonitor by nege verskillende stadiums van ‘n
vrugtekosentraat prosesseringsfabriek tydens die funksionering van óf 'n
hersirkulerende óf ‘n deurlopende (nie-hersirkulerende) leigeut waterstelsel.
Alicyclobacillus vlakke was beduidend hoër in gemaalde vrugte, enkelsterkte sap,
konsentraat en die finale gepasteuriseerde produk (± 30 °Brix), gedurende die
funksionering van 'n hersirkulerende leigeutstelsel, in vergelyking met die funksionering
van ‘n deurlopende leigeutstelsel (P < 0.05 ). Ongeag van die leigeutstelsel, is hoë
vlakke Alicyclobacillus gevind in konsentraat en kondensaat water ('n by-produk van die
sap konsentrasie porses) vanuit die verdamper, en maak dit dus ‘n punt van belang
tydens die vervaardiging van vrugtekonsentraat. Daar is gevind dat
vervaardigingspraktyke soos die hersirkulasie van leigeut water en die herwinnig van
kondensaat water moontlike risiko’s inhou vir die besoedeling en akkumulasie van
Alicyclobacillus in vrugtekosentrate en die prosesseringsomgewing.
Die effek van aaneenlopende prosesseringstye op Alicyclobacillus was
gemonitor in 'n vrugtekosentraat prosesseringsfabriek wat teen volle kapasiteit
prosesseer. Steekproefneming het elke 12 h by vier prosesseringsstadiums geskied,
tydens 'n prosesseringstempo van 1.8 - 2.0 t h-1 vir 108 h. Vegetatiewe selle het
beduidend toegeneem (P < 0.05) in die enkelsterkte sap en kondensaat water na 84 uur
van prosessering, met 3.15 en 3.85 log10 kve mL-1, onderskeidelik verhaal. Soortgelyke akkumulasiepatrone vir vegetatiewe selle was waargeneem in konsentraat en die finale
gepasteuriseerde produk. Endospore in enkelsterkte sap, konsentaat en die finale
produk was ook die hoogste na 84 uur van prosessering, met 1.32, 1.59 en
1.64 log10 kve mL-1, onderskeidelik. Wanneer vrugtekonsentraat fabrieke teen volle
kapasiteit prosesseseer, kan 'n beperking in aaneenlopende prosesseringstye tot onder
84 h tussen CIP prosedures, gepaard met goeie vervaardigingspraktyke, die
akkumulasie van Alicyclobacillus in vrugte konsentate verminder.
Die effek van verskillende vrug variëteite se vel tipes, spesifiek harige-vel
steenvrugte (perske en appelkoos) en gladde-vel kernvrugte (appel en peer) op die
voorkoms van Alicyclobacillus in vrugtekonsentrate was ondersoek. Appel konsentaat
monsters het die hoogste voorkoms van vegetatiewe Alicyclobacillus selle gehad
(gemiddelde %), met (50%), gevolg deur appelkoos (40%), perske (15%) en peer (10%)
konsentraat. Die voorkoms van Alicyclobacillus endospore in vrugte konsentraat
monsters was weer die hoogste in appel (50%), gevolg deur peer (25%), appelkoos
(20%), en perske (10%) konsentraat. Die voorkoms van Alicyclobacillus vegetatiewe
selle en endospore het nie betekenisvol tussen konsentrate van harige-vel en gladdevel
vrug variëteite verskil nie (P > 0.05). Die gevolgtrekking was dat vrugte wasstappe,
voor die prosessering van vrugtekonsentraat, van meer belang is vir die beheer van
Alicyclobacillus as die vel tipe van die vrug variëteit wat geprosesseer word.
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Ciclagem de nutrientes em sistemas de rotação de culturasOlibone, Ana Paula Encide [UNESP] 05 December 2008 (has links) (PDF)
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olibone_ape_dr_botfca.pdf: 3141451 bytes, checksum: 841b3864f5b41bea3ef33884436e0802 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As espécies utilizadas em sistemas de rotação de culturas comportamse de maneira diferente quanto à absorção e ciclagem de nutrientes. Além disso, a absorção de nutrientes é influenciada pelas propriedades físicas do solo, capazes de modificar o crescimento e desenvolvimento radicular. O presente trabalho teve como objetivo estudar a ciclagem de nutrientes em três sistemas de rotação de culturas, relacionando-a à atividade radicular da braquiária e sorgo, em sistema de semeadura direta, escarificado (SDCE) e sem escarificação (SDSE), em Nitossolo Vermelho de textura argilosa na cidade de Botucatu-SP. Além das plantas de cobertura também se avaliou a atividade radicular das culturas do milho e da soja. O sistema de rotação foi implantado na safra de 2005/2006 como segue: (1) milheto / soja / sorgo / milho / sorgo/ soja; (2) milheto / soja / braquiária / milho / braquiária / soja e (3) milheto / soja / mamona + braquiária / milho / mamona + braquiária / soja. O delineamento experimental foi o de blocos ao acaso com quatro repetições em parcelas subdivididas. A condução do experimento deu-se por dois anos agrícolas (2006/2007; 2007/2008) para possível observação de algum efeito acumulativo dos tratamentos. A atividade radicular das plantas de cobertura (novembro 2006), do milho (fevereiro 2007) e da soja (dezembro 2007) foi avaliada indiretamente, usando-se rubídio como marcador. Aplicou-se 3 mL da solução de nitrato de rubídio no solo com cateter, a 0,05; 0,10; 0,20, 0,40 e 0,60 m de profundidade e a 0,11 e 0,22 m de distância da planta de referência. Decorrido 4 dias da aplicação, coletou-se as respectivas partes aéreas das plantas, as quais foram secas, moídas e digeridas por via úmida para determinação do teor de rubídio em absorção atômica. Também foram analisadas... / The species used in crop rotation systems differ in nutrient absorption and cycling. Moreover, nutrient absorption is influenced by soil physical properties, which may affect root growth and its development. The present research had as objective to investigate nutrient cycling in three crop rotation systems and its relation to root activity of Brachiaria and sorghum in no tillage system, with and without chiselling. The experiment was carried out in Botucatu, SP, Brazil, in a Red Nitosol, with clay texture. The rotation system was implemented in 2005/2006 and carried out for two growing seasons (November of 2006 and 2007). Crop rotation systems were: (1) Pearl millet / soybean / sorghum / maize / sorghum / soybean; (2) Pearl millet / soybean / Brachiaria / maize / Brachiaria / soybean and (3) Pearl millet / soybean / Brachiaria + castor bean / maize / Brachiaria + castor bean / soybean. The experimental design was the completely randomized block with split-plots and four replications. Root activity was evaluated for either cover crops or maize and soybean. Root activity of cover crops (November of 2006 and 2007), maize (February of 2007) and soybean (December of 2007) was indirectly evaluated, using Rubidium as marker. The solution of 3 mL of rubidium nitrate was applied in soil with a catheter, at 0.05, 0.10, 0.20, 0.40 and 0.60 m depths and at 0.11 and 0.22 m away from the plant in question. The respective shoots were collected, dried, grounded and submitted to humid digestion 4 days after the application to evaluate rubidium level through atomic absorption. Chemical characteristics and soil penetration resistance were also evaluated at 0.00-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40 and 0.40-0.60 m depths in the respective growing seasons. According to Rb levels observed in dry matter, the highest... (Complete abstract click electronic access below)
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A política pública de emprego: entre a pracarização desprotegida e a precarização protegida. Um estudo comparativo entre Brasil e Itália / A política pública de emprego: entre a pracarização desprotegida e a precarização protegida. Um estudo comparativo entre Brasil e Itália / The public employment policy: between unprotected precarious and protected precarious. A comparative study between Brazil and Italy / The public employment policy: between unprotected precarious and protected precarious. A comparative study between Brazil and ItalyEdnéia Alves de Oliveira 27 May 2010 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Este trabalho discute a política de emprego implementada no Brasil e na Itália nos últimos 10 anos. A ideia central é de que a política de emprego vem sendo alvo de estratégias por parte do Estado brasileiro e italiano como forma de responder ao problema endêmico do desemprego e se encontra dentro das exigências propostas pelas agências multilaterais para minimizar os impactos das mudanças em curso no âmbito do trabalho. Embora o desemprego sempre tenha sido um elemento fundamental na dinâmica das relações sociais de produção capitalista, tendo em vista que a formação de um excedente de trabalhadores é condição fundamental para a extração da taxa de mais-valia, através do trabalho não pago e expropriado pelo capitalista, ele vem sendo considerado como um processo natural, sem qualquer vinculação com a lógica da acumulação capitalista e, portanto, as políticas de emprego revelam-se como medidas pontuais que tendem a responsabilizar os sujeitos pela sua "incapacidade" de se adequar às mudanças em curso. neste sentido, as ações propostas reforçam o incentivo ao empreendedorismo, a precarização das condições de trabalho, no incremento do trabalho feminino e juvenil e na retirada gradativa de direitos sociais e trabalhistas. As consequências não podem ser percebidas igualmente nos dois países, haja vista as condições sócio-históricas que deram luz ao Estado social permitindo que na Itália as mudanças em curso apontem para uma precarização protegida e no Brasil numa precarização desprotegida. / This paper discusses the employmet policy implemented over the last ten years in Brazil and Italy. the central idea is that employment policy has been the target of strategies for both countries as a way to respond to the endemic problem of unemployment and lies within the requirements recommend by the multilateral agencies to minimize the impacts of the changes underway in scope of work. Although unemployment has always been a key element in the dynamics of social relations of capitalist production, considering that the formation of a surplus of workers is a fundamental condition for the extraction rates of a surplus value through the unpaid labor and expropriated by the capitalist. He has been considered as a problem of natural order not directly associated with the dynamics of capitalism accumulation and, therefore, employment polices are revealed as ad hoc measures that to blend individuals for their "inability" to suit changes underway. In this sense, the proposed action in turne encourage entrepreneurship, the precarious conditions and working relations in the increase of youth work and woman and phases withdrawal of rights and guarantees for workers, providing, on one hand, higer capitals gains and another, the impoversishment of workers. Increasing overcrowding on and generating a mass of workers left over, but with different impacts in the face of the construction welfare state implemented in both countries, revelaing in the case of Italy a pr
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Respostas morfológicas e produtivas do capim-xaraés, sob pastejo, à adubação nitrogenada /Santos, Thiago Martins dos. January 2010 (has links)
Resumo: O adubo nitrogenado é um dos mais caros e, para assegurar retorno econômico da atividade pecuária e evitar danos ao ambiente, é necessário conhecer a dose adequada de nitrogênio a aplicar. Objetivou-se com este trabalho avaliar a resposta morfológica e produtiva do capim-xaraés, sob pastejo, à adubação nitrogenada. O experimento foi conduzido em condições de campo, no Instituto de Zootecnia, Nova Odessa-SP. O delineamento experimental utilizado foi o de blocos ao acaso, com seis doses de nitrogênio (0; 125; 250; 375; 500 e 625 kg ha-1 de N por ano) e quatro repetições. Foram avaliadas características estruturais, massa de forragem no pré e no pós-pastejo, acúmulo de forragem, eficiência de conversão do N fertilizante em forragem, perdas de forragem no pastejo e eficiência de pastejo durante oito ciclos de pastejo do capim-xaraés. O nitrogênio aumentou o acúmulo de forragem do capim- -xaraés e das perdas de forragem pelo pastejo. A dose de 354 kg ha-1 de N proporcionou o máximo acúmulo de forragem no período chuvoso, e com 250 kg ha-1 é possível obter 90% do máximo. Houve efeito residual da adubação no acúmulo de forragem. A maior eficiência de conversão do N fertilizante em forragem foi obtida com 125 kg ha-1 de N. A adubação nitrogenada propiciou aumento na altura de plantas e na densidade de perfilhos. A eficiência de pastejo aumentou em função da adubação nitrogenada, mas ficou abaixo de 50%. / Abstract: The objective of this study was to evaluate the morphologic and productive response of xaraés palisadegrass, under grazing, to nitrogen fertilization. The experiment was carried out under field conditions at the Instituto de Zootecnia, Nova Odessa-SP. The experimental design was randomized blocks design with six nitrogen rates (0; 125; 250; 375; 500 and 625 kg ha-1 N per year) and four replications. Structural characteristics, pre and post-grazing forage mass, forage accumulation, agronomic efficiency, grazing losses and grazing efficiency were evaluated during eight xaraes palisadegrass grazing cycles. Nitrogen increased forage accumulation and grazing losses. Maximum forage accumulation (sum of six grazing cycles) was achieved with 354 kg ha-1 N, however, 250 kg ha-1 N corresponded to 90% of the maximum. There was a residual effect of fertilization. The highest efficiency nitrogen use was obtained with 125 kg ha-1 N. Nitrogen fertilization resulted in an increase in plant height and tiller density. Grazing efficiency increased with nitrogen fertilization, but it remained below 50%. / Orientador: Manoel Evaristo Ferreira / Coorientadora: Patrícia Sarmento / Banca: William Natale / Banca: Francisco Antonio Monteiro / Mestre
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O excedente econômicoFreitas, Luís Fernando Alcoba de January 2006 (has links)
Este trabalho procura mostrar a evolução do conceito de excedente na história do pensamento econômico. Busca expor como variados autores, através do uso do conceito de excedente e de valor excedente, pretendem explicar aspectos característicos e essenciais da economia capitalista em épocas específicas da história. Isto é feito, visto a enorme extensão possível de pesquisa, pela seleção de um conjunto de autores, em que se pode constatar as primeiras formulações do conceito, seu desenvolvimento e até a utilização dos conceitos de excedente e de valor excedente para mostrar aspectos característicos da época dos autores, da economia capitalista, e da sua evolução, tais como: a acumulação do capital, a grande empresa, o crescimento do setor serviços, o caráter rentista, a dimensão financeira do capitalismo contemporâneo, dentre outros aspectos. Assim, desde a origem com os fisiocratas, passando pelos economistas clássicos, por Marx, pelos denominados autores Marxistas, até autores contemporâneos como Sraffa, Kalecki e Robinson se busca verificar como o excedente e o valor excedente estão inseridos nas concepções teóricas desses autores, para análise do capitalismo. Esse trabalho procura mostrar, portanto, que, dentro dessa diversidade o excedente e o valor excedente constituem-se em categorias fundamentais para a análise da economia capitalista. / The objective of this work is to show the evolution of the concept of surplus in the history of the Economic thought. It tries to show how different authors, through the use of the concepts of surplus and surplus value, intend to explain essential and particular features of the capitalist economy in specific times of history. Taking into account the enormous range of possible research, this is done through a selection of a group of authors, from which it is possible to find the first formulations of the concept, its development and the use of the concepts of surplus and surplus value to show specific features from the period of time the authors belong to, of the capitalist economy and its evolution, such as: the accumulation of capital, the big company, the growth of the retailing sector, the renting character, and the financial dimension of the contemporary capitalism among other aspects. Therefore, since its origins with the physiocrats, going from the classic economists, such as Marx, and the so called Marxist authors, to the contemporary authors such as Sraffa, Kalecki e Robinson this work aims at examining how the surplus concept and the surplus value are embedded in the theoretical conceptualizations of these authors, to analyze the capitalism. This work intends to show, therefore, that among this diversity of approaches, the surplus concept and the surplus value, are fundamental categories to the analysis of the capitalist economy.
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