Credit Channel without the LM Curve

This paper extends Bernanke and Blinder (1988)'s macroeconomic model of credit channel to an environment where the monetary authority has control over a short-term interest rate. The comparative statics regarding changes in the market interest rate, in the required reserve ratio over bank deposits, and in the risk of public bonds are highlighted.

Evidence for Possible Phase-Separations in RuSr2(Gd,Ce)2Cu2O10-delta

An unusual thermal-magnetic hysteresis was observed between a minor magnetic transition around 120 K and the main one at 80 K in superconducting RuSr2(R,Ce)2Cu2O10-delta (Ru1222R) samples, where R = Gd or Eu, down to a submicron length-scale. The observation suggests a possible phase-separation and is consistent with the very small but universal demagnetizing factor observed, which is difficult to reconcile with the canted spin-structure previously proposed. In such a scenario, the unusual superconducting properties of the Ru-based cuprates can also be understood naturally.Comment: 8 pages, 3 figures, submitted to Phys. Rev. B, "Rapid Communications" (September 26, 2001

Ocorrência de esporos de fungos micorrizicos arbusculares no Baixo Amazonas.

bitstream/item/40517/1/Boletim-Pesquisa-5-CPATU.pd

Ultrasonic Characterization of Interfacial Fatigue Damage in Metal Matrix

In recent years there has been significant interest in titanium-based metal-matrix composites for structural applications in airframe and engine components. In many applications, these composites are integrated into structural components by diffusion bonding. Thus the composites are subjected to temperature/time cycles during material processing and to temperature/stress cycles in service. One major effect of these thermomechanical cycles is that they significantly alter the microstructure of the composite constituents and the residual stresses. Even though the changes in microstructure and residual stresses may not affect the composite properties greatly, they often lead to completely different failure mechanisms. Therefore, it is important to understand the role of heat treatment on composite damage development, which can only be done by nondestructively monitoring damage initiation and development during the failure process

Mutants of chinese hamster cells deficient in thymidylate synthetase

Stable mutants of Chinese hamster V79 cells deficient in thymidylate synthetase (TS; E.C. 2.1.1.45) have been selected from cultures grown in medium supplemented with folinic acid, aminopterin, and thymidine (FAT). After chemical mutagenesis, the frequency of colonies resistant to the “FAT” medium increased more than 100-fold over the spontaneous frequency. The optimal expression time of the mutant phenotype was 5–7 days after mutagen treatment. The recovery of FAT-resistant colonies in the selective medium was not affected by the presence of wild-type cells at a density below 9,000 cells per cm 2 . All 21 mutants tested exhibited thymidine auxotrophy; neither folinic acid nor deoxyuridine could support mutant cell growth. There was no detectable TS activity in all 11 mutants so far examined and only about 50% of wild-type activity in three prototrophic revertants, as measured by whole-cell and cell-free enzyme assays. The apparent Michaelis-Menten constant (K m ) for deoxyuridine-5′-monophosphate and inhibition constant (K i ) for 5-fluorodeoxyuridine-5′-monophosphate, measured by whole-cell enzyme assay, appear to be similar for the wild-type and revertant cell lines. Using 5-fluoro-[6 3 H]-2′-deoxyuridine 5′-monophosphate as active site titrant, the relative amounts of TS in crude cell extract from the parental, revertant, and mutant cells were shown to exist in a 1:0.5:0 ratio. Furthermore, the enzymes from two revertants were more heat labile than that of V79 cells. These properties, taken together, suggest that the FAT-resistant, thymidine auxotrophic phenotype may be the result of a structural gene mutation at the TS locus. The availability of such a mutant facilitates studies on thymidylate stress in relation to DNA metabolism, cell growth, and mutagenesis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49874/1/1041200202_ftp.pd

Credit channel without the LM curve

This paper extends Bernanke and Blinder (1988)'s macroeconomic model of credit channel to an environment where the monetary authority has control over a short-term interest rate. The comparative statics regarding changes in the market interest rate, in the required reserve ratio over bank deposits, and in the risk of public bonds are highlighted

The first operation and results of the Chung-Li VHF radar

The Chung-Li Very High Frequency (VHF) radar is used in the dual-mode operations, applying Doppler beam-swinging as well as the spaced-antenna-drift method. The design of the VHF radar is examined. Results of performance tests are discussed