Aspects of Optimal Unemployment Insurance: Search, Leisure and Capital Market Imperfections

The object of this paper is to examine the importance of capital market assumptions. A special continuous-time model is developed in sections II-IV which is applicable to the perfect capital market case. It can also be used when there is no capital market at all (section IV). For 'reasonable' parameter values the optimal replacement rate (ratio of benefits to gross wage) appears to be less than 20% when capital markets are perfect but over 70% when they are non existent (i.e. no saving or dis-saving).

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Wear Mechanisms of Hydrogenated DLC in Oils Containing MoDTC

Diamond-Like Carbon (DLC) coatings are well known for offering excellent tribological properties. They have been shown to offer low friction and outstanding wear performance in both dry and lubricated conditions. Application of these coatings for automotive components is considered as a promising strategy to cope with the emerging requirements regarding fuel economy and durability. Commercially available oils are generally optimised to work on conventional ferrous surfaces and are not necessarily effective in lubricating non-ferrous surfaces. Recently, the adverse effect of the Molybdenum DialkyldithioCarbamate (MoDTC) friction modifier additive on the wear performance of the hydrogenated DLC has been reported. However, the mechanisms by which MoDTC imposes this high wear to DLC are not yet well understood. A better understanding of DLC wear may potentially lead to better compatibility between DLC surfaces and current additive technology being achieved. In this work, the wear properties of DLC coatings in the DLC/cast iron (CI) system under boundary lubrication conditions have been investigated to try to understand what appears to be a tribocorrosion-type process. A pin-on-plate tribotester was used to run the experiments using High Speed Steel (HSS) plates coated with 15 at.% hydrogenated DLC (a-C:15H) sliding against CI pins or ceramic balls. The lubricants used in this study are typical examples of the same fully formulated oil with and without ZDDP. The friction and wear responses of the fully formulated oils are discussed in detail. Furthermore, Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX), Focused Ion Beam (FIB) and Transmission Electron Microscopy (TEM) were used to observe the wear scar and propose wear mechanisms. The X-ray Photoelectron Spectroscopy (XPS) analysis was performed on the tribofilms to understand the tribochemical interactions between oil additives and the DLC coating. Nano-indentation analysis was conducted to assess potential structural modifications of the DLC coating. Coating hardness data could provide a better insight into the wear mode and failure mechanism of such hard coatings. Given the obtained results, the wear behaviour of the hydrogenated DLC coating was found to depend not only on the presence of ZDDP in the oil formulation but also on the counterpart type. This study revealed that the steel counterpart is a critical component of the tribocouple leading to MoDTC-induced wear of the hydrogenated DLC

RAÇÃO FARELADA COM DIFERENTES GRANULOMETRIAS EM FRANGOS DE CORTE

Em geral, o diâmetro geométrico médio (DGM) das partículas das rações não tem afetado o desempenho de frangos de corte, em situações experimentais. Por meio deste, objetivou-se verificar se o mesmo ocorre em criações comerciais e, também, avaliar possíveis benefícios econômicos do uso da ração com maior DGM. Para isso, o presente trabalho buscou avaliar o desempenho zootécnico em frangos de corte da linhagem ROSS, do 1º ao 42º dia de idade, arraçoados com diferentes granulometrias. O experimento foi conduzido nos meses de agosto e setembro de 1998, no aviário experimental da Cooperativa Agrícola Consolata Ltda. Em delineamento em blocos casualizados, foram testados os DGMs: 0,833, 0,703 e 1,058 mm, na fase pré-inicial; 0,829, 0,703 e 1,086 mm, na fase inicial, e; 0,818, 0,649 e 0,912 mm, na fase de crescimento. O DGM dos tratamentos apresentou influência (P < 0,05) sobre o consumo de ração de pintainhos na fase pré-inicial, sendo observadas poucas modificações (P > 0,05) no desempenho das outras fases de criação e na mortalidade das aves. Entretanto, a lucratividade inerente aos tratamentos, pode ser aumentada em até 2,78%, em função da diminuição da moagem e/ou aumento do DGM. Use of mashed rations with different particle sizes for broilers Abstract In general, the average geometric diameter (AGD) of ration has not affected broilers performance in experimental situations. The objective of this experiment was to investigate if such statement is true also for commercial farms and to evaluate the possible economic benefits of using larger ration particle sizes. For that, in the present work, ROSS broilers had theis performance estimated, from the 1st up to the 42nd day of age, fed with rations of different particle sizes. The experiment was developed during August and September of 1998, in the experimental aviary from Cooperativa Agrícola Consolata Ltda. Statistical design was of random blocks and treatment were (AGD's): 0.833, 0.703 and 1.058 mm, in the pre-initial phase; 0.829, 0.703 and 1.086 mm, in the initial phase, and; 0.818, 0.649 and 0.912 mm, in the growth phase. Treatments AGDs treatment showed influence (P < 0.05) on the consumption of chick ration in the pre-initial phase. Few modifications were observed (P > 0.05) in the acting of the other feeding phases and in the mortality of the birds. However, the gross margin related to treatments can be increased up to 2.78%, as a result of the decrease of the grinding and/or AGDs increase

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UTILIZAÇÃO DO HALQUINOL COMO PROMOTOR DE CRESCIMENTO E COADJUVANTE NO CONTROLE DA COCCIDIOSE EM FRANGOS DE CORTE

O principal objetivo deste trabalho foi o de estudar a influência da utilização do halquinol (uma mistura de 5,7-dicloro-8-quinolinol, 5-cloro-8 quinolinol e 7-cloro-8-quinolinol) como promotor de crescimento, bem como sua possível ação no controle da coccidiose, em frangos de corte. Foram analisados parâmetros como ganho de peso, conversão alimentar, viabilidade e índice de eficiência produtiva. Foram constituídos 6 tratamentos, num total de 2880 aves criadas em piso, com diferentes níveis da droga na ração. Observou-se que a utilização do halquinol como promotor de crescimento não alterou significativamente (P>0.05) o ganho de peso, a conversão alimentar e a viabilidade das aves. A associação do halquinol a outros promotores de crescimento também não influenciou positivamente (P>0.05) os parâmetros zootécnicos avaliados. No segundo estudo, num experimento em gaiolas procurou-se avaliar a ação do halquinol no controle da coccidiose, comparando-se a ação de 30 g/ton do produto associado ou não ao coccidiostático maduramicina frente à inoculação de diferentes Eimerias. Foram utilizadas 40 aves criadas em gaiolas que receberam um inoculo misto de E.tenella, E. acervulina e E. máxima, sendo então realizado escore de lesões. Como resultado observou-se que a utilização do halquinol potencializa a ação da maduramicina no controle da E. acervulina, não apresentando entretanto qualquer efeito no controle da E. máxima e E.tenella. Utilization of halquinol as a growth promoter and coadjuvanto on coccidiosis control in broilers Abstract The main purpose of this stud was to invetigate the clorade-8-hidroxiquinolim (halquinol) drug influence as a promoter of growth, as well as it´s possible action in the coccidiosis control in chicken for human consumption. Some parameters have been analised such as weight gain, food conversion ,viability and produtive efficiency index. Six treatments were undertaken, on a total of 2880 birds raised on flat surface with different levels of drug in then feed .It was noted that the utilization of halquinol as a promoter of growth didn´t alter significantly (P>0.05) the weight gain, the feed conversion and the viability of the birds. The addition of halquinol to other growth promoters also didn´t influence positively (P>0.05) the evalueted zootechnical parameters. In the second study, during a bird cage experiment there was no attempt to evaluate the halquinol action in the control of coccidiosis by comparing the of 30 g/ton of clorade-8-hidroxiquinolin (halquinol) associade or not with maduramicine coccidiostatic during the Eimerias innoculation. There were utilize 40 cages raised birds wich received a mixed E. tennela, E. acervulina e E. maxima inoculum, and was performed a lesion count. As a result it was observed that the utilization of halquinol potencializes the maduramicine action in the control of E. acervulina; however no showing any effect in the control of E.maxima and E. tenella

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