Financial distress, financial constraint and investment decision: Evidence from Brazil

This paper analyses the presence of financial constraint in the investment decisions of 367 Brazilian firms from 1997 to 2004, using a Bayesian econometric model with group-varying parameters. The motivation for this paper is the use of clustering techniques to group firms in a totally endogenous form. In order to classify the firms we used a hybrid clustering method, that is, hierarchical and non-hierarchical clustering techniques jointly. To estimate the parameters a Bayesian approach was considered. Prior distributions were assumed for the parameters, classifying the model in random or fixed effects. Ordinate predictive density criterion was used to select the model providing a better prediction. We tested thirty models and the better prediction considers the presence of 2 groups in the sample, assuming the fixed effect model with a Student t distribution with 20 degrees of freedom for the error. The results indicate robustness in the identification of financial constraint when the firms are classified by the clustering techniques. (C) 2010 Elsevier B.V. All rights reserved.

Influence of the microstructure in the collapse of a residual clayey tropical soil

A typical residual clayey soil originating from basalt in southern Brazil has been analyzed in order to assess the influence of wetting-induced deformation and microstructural features on the collapse behavior. Single and double oedometer tests were undertaken on a soil profile to 9 m depth. The results indicated collapsible behaviour at all profile depths. The influence of pre-consolidation stress and pedogenetic factors in the variability of the physical characteristics of the soil and in the magnitude of the collapse was noted. The collapse coefficient has been shown to be related to the both the microaggregate plasma and the varying nature of the pores and their interconnectivity.

Microstructure and mechanical properties of laser-welded joints of TWIP and TRIP steels

With the aim of investigating a laser-welded dissimilar joint of TWIP and TRIP steel sheets, the microstructure was characterized by means of OM, SEM, and EBSD to differentiate the fusion zone, heat-affected zone, and the base material. OIM was used to differentiate between ferritic, bainitic, and martensitic structures. Compositions were measured by means of optical emission spectrometry and EDX to evaluate the effect of manganese segregation. Microhardness measurements and tensile tests were performed to evaluate the mechanical properties of the joint. Residual stresses and XRD phase quantification were used to characterize the weld. Grain coarsening and martensitic areas were found in the fusion zone, and they had significant effects on the mechanical properties of the weld. The heat-affected zone of the TRIP steel and the corresponding base material showed considerable differences in the microstructure and properties. (C) 2009 Elsevier B.V. All rights reserved.

Wear mechanisms and microstructure of pulsed plasma nitrided AISI H13 tool steel

AISI H13 tool steel discs were pulsed plasma minded during different times at a constant temperature of 400 degrees C Wear tests were performed in order to study the acting wear mechanisms The samples were characterized by X-ray diffraction, scanning electron microscopy and hardness measurements The results showed that longer nitriding times reduce the wear volumes. The friction coefficient was 0.20 +/- 0 05 for all tested conditions and depends strongly on the presence of debris After wear tests, the wear tracks were characterized by optical and scanning electron microscopy and the wear mechanisms were observed to change from low cycle fatigue or plastic shakedown to long cycle fatigue These mechanisms were correlated to the microstructure and hardness of the nitrided layer (C) 2010 Elsevier B V All rights reserved

Dependence of Barkhausen jump shape on microstructure in carbon steel

The present work presents measurements of the Magnetic Barkhausen Noise (MBN) in commercial AISI/SAE 1005 steel samples for different grain sizes. The correlation between the shape of the MBN jump and the grain size is established. The results show the existence of types of MBN jumps. Also, the outcome shows that one of these types of MBN jumps become ""squarer"" with the decrease of grain size.

Microstructure and texture of duplex stainless steel after melt-spinning processing

The microstructure and texture of melt-spun UNS S31803 (DIN W. Nr. 1. 4462) duplex stainless steel were analyzed after casting and solution treatment. The cast ribbons contained austenite (gamma) and ferrite (alpha or delta) with roughly equal compositions. The alpha and gamma had < 100 > and < 110 > partial fiber textures, respectively. After solution treatment, the texture was maintained, the amount of gamma phase increased, and the alloying elements were partitioned as expected, according to whether they were ferrite or austenite stabilizers. (c) 2006 Elsevier Inc. All rights reserved.

Microstructure and texture assessment of Al-Mn-Fe-Si (3003) aluminum alloy produced by continuous and semicontinuous casting processes

Aluminum sheets are currently produced by the direct-chill process (DC). The need for low-cost aluminum sheets is a challenge for the development of new materials produced by the twin roll caster (TRC) process. It is expected that sheets produced from these different casting procedures will differ in their microstructure. These differences in microstructure and in the crystallographic texture have great impact on sheet mechanical properties and formability. The present study investigated microstructure and evaluated texture of two strips of Al-Mn-Fe-Si (3003) aluminum alloy produced by TRC and by hot-rolling processes. It was possible to notice that the microstructure, morphology, and grain size of the TRC sample were more homogenous than those found in hot-rolled samples. Both strips, obtained by the two processes, showed strong texture gradient across the thickness.

ANNEALING EFFECTS ON THE MICROSTRUCTURE OF FERRITIC-MARTENSITIC ODS-EUROFER STEEL

Oxide dispersion strengthened (ODS) ferritic/martensitic (FM) steels are promising candidates for structural applications in future fusion power reactors. In order to evaluate the thermal stability of 80% cold-rolled ODS-EUROFER, samples were annealed for 1 h at temperatures up to about 0.9 T(m), where T(m) is the absolute melting point. The characterization of the annealed samples was performed using transmission electron microscopy and electron backscatter diffraction. Results show that static recovery is the main softening mechanism of this steel when annealed below 800 degrees C. The volume fraction of recrystallized grains is quite small (below 0.10). Above 900 degrees C, martensitic transformation takes place causing pronounced hardening. Large M(23)C(6) particles are found at the grain boundaries after tempering at 750 degrees C for 2 h.

Sampled Control for Mean-Variance Hedging in a Jump Diffusion Financial Market

In this technical note we consider the mean-variance hedging problem of a jump diffusion continuous state space financial model with the re-balancing strategies for the hedging portfolio taken at discrete times, a situation that more closely reflects real market conditions. A direct expression based on some change of measures, not depending on any recursions, is derived for the optimal hedging strategy as well as for the ""fair hedging price"" considering any given payoff. For the case of a European call option these expressions can be evaluated in a closed form.

Influence of chemical interesterification on thermal behavior, microstructure, polymorphism and crystallization properties of canola oil and fully hydrogenated cottonseed oil blends

This work evaluated chemical interesterification of canola oil (CaO) and fully hydrogenated cottonseed oil (FHCSO) blends, with 20%, 25%, 30%, 35% and 40%(w/w) FHCSO content. Interesterification produced reduction of trisaturated and increase in monounsaturated and diunsaturated triacylglycerols contents, which caused important changes in temperatures and enthalpies associated with the crystallization and melting thermograms. It was verified reduction in medium crystal diameter in all blends, in addition crystal morphology modification. Crystallization kinetics revealed that crystal formation induction period and maximum solid fat content were altered according to FHCSO content in original blends and as a result of random rearrangement. Changes in Avrami constant (k) and exponent (n) indicated, respectively, that interesterification decreased crystallization rates and altered crystalline morphology. However, X-ray diffraction analyses showed randomization did not change the original crystalline polymorphism. The original and interesterified blends had significant predominance of beta` polymorph, which is interesting for several food applications. (C) 2009 Elsevier Ltd. All rights reserved.

Thermal Behavior, Microstructure, Polymorphism, and Crystallization Properties of Zero Trans Fats from Soybean Oil and Fully Hydrogenated Soybean Oil

Blends of soybean oil (SO) and fully hydrogenated soybean oil (FHSBO), with 10, 20, 30, 40, and 50% (w/w) FHSBO content were interesterified under the following conditions: 20 min reaction time, 0.4% sodium methoxide catalyst, and 500 rpm stirring speed, at 100 A degrees C. The original and interesterified blends were examined for triacylglycerol composition, thermal behavior, microstructure, crystallization kinetics, and polymorphism. Interesterification produced substantial rearrangement of the triacylglycerol species in all the blends, reduction of trisaturated triacylglycerol content and increase in monounsaturated-disaturated and diunsaturated-monosaturated triacylglycerols. Evaluation of thermal behavior parameters showed linear relations with FHSBO content in the original blends. Blend melting and crystallization thermograms were significantly modified by the randomization. Interesterification caused significant reductions in maximum crystal diameter in all blends, in addition to modifying crystal morphology. Characterization of crystallization kinetics revealed that crystal formation induction period (tau (SFC)) and maximum solid fat content (SFC(max)) were altered according to FHSBO content in the original blends and as a result of the random rearrangement. Changes in Avrami constant (k) and exponent (n) indicated, respectively, that-as compared with the original blends-interesterification decreased crystallization velocities and modified crystallization processes, altering crystalline morphology and nucleation mechanism. X-ray diffraction analyses revealed that interesterification altered crystalline polymorphism. The interesterified blends showed a predominance of the beta` polymorph, which is of more interest for food applications.