Branching versus linear logics yet again

A brief overview is given of the temporal logics used in concurrent program verification and in database and systems specification. The properties of the underlying modal frame structures are analysed. The relative advantages of the linear and branching approaches are discussed. The state versus path formulas controversy is revisited. A meta-linear operatorL is proposed and compared with the in all trajectories operator considered in the language CTL*. The usefulness of the new operator within the context of a layered methodology for database and information systems specification and verification is illustrated. The operator is seen as a frame change operator and other interesting operators of this class are referred. Finitary and infinitary axiomatisations are given for the operatorL. The proof of the completeness of the infinitary axiomatisation is briefly outlined. This proof requires an appropriate extension of the usual Henkin methods.     

Quantum circuit’s reliability assessment with VHDL-based simulated fault injection

This paper presents a VHDL-based simulated fault injection (SFI) methodology for quantum circuits. The main objective is to attain a high error modeling capability at a technology independent level. For this purpose, gate level simulation models for quantum circuits have been developed using VHDL. The proposed methodology relies on specific techniques inspired from the simulated fault injection techniques developed for classical CMOS circuits: saboteurs and mutants. In order to perform the simulation campaigns, a library of quantum gates and simulated fault injection components has been developed. The simulation results show that a wide range of quantum faults and error models has been addressed. Furthermore, a comparison between the two SFI techniques is presented.     

Estrogen and the neural mediation of female–male mounting in the rat.

Sexually receptive females mount sexually sluggish males to entice them to copulate, and estrogen and male olfactory cues mediate this female–male mounting (FMM) in the rat. This study examined whether brain regions that concentrate steroid hormones and receive olfactory projections were important for the mediation of FMM. Fos induction was observed within the medial amygdala, medial preoptic area, and ventromedial hypothalamus of ovariectomized, hormone-primed rats that displayed FMM compared with rats that did not. Excitotoxic lesions of those regions eliminated FMM, whereas implants of crystalline estradiol benzoate to the ventromedial hypothalamus, but not the medial preoptic area or medial amygdala, restored FMM. These data indicate that the ventromedial hypothalamus is a critical area of convergence of hormonal, olfactory, and somatosensory inputs for FMM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Designing polylactide/clay nanocomposites for textile applications: Effect of processing conditions,spinning, and characterization

An experimental study was carried out to design polylactide (PLA)-clay nanocomposites for developing fibers. PLA and 1–10 wt % of a selected organomodified bentonite (Bentone® 104-B104) were melt mixed to examine the effect of processing conditions (temperature, shear, residence time) on the morphology of performed polymer nanocomposites (PNC). Because of a good compatibility with PLA matrix, the dispersion of B104 occurred under different conditions without difficulty, and a similar morphology was obtained. The results obtained showed that at low temperature of mixing, the shear stress exerted on polymer has a key role on the extent of intercalation and delamination. Upscale experiments were further performed using optimized conditions and 4 wt % B104 was added to PLA matrix by melt blending to produce PNC for spinning. Then, the recovered PNC were melt spun to produce multifilaments yarns, and it was demonstrated that surprisingly, it is not necessary to use a plasticizer to spin a blend with 4 wt % B104. The properties of the yarns have been studied in terms of clay dispersion as well as thermal, mechanical, and shrinkage properties. B104 could be added up to 4 wt % into PLA without detrimentally sacrificing the tensile strength of melt-spun filaments, especially at high draw ratio. Interestingly, the PNC-based multifilaments were knitted and the flammability studied using cone calorimeter at 35 kW/m². A strong decrease, up to 46%, of the heat release rate was measured. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of procedures and transfer modes in MAG welding in the reduction of deformations on marine structure panels

With the growth of the Brazilian shipbuilding industry, problems from the production processes emerged in the form of distortions and residual stresses. This study researched the influence of welding procedures (sequence, welding direction and reverse pass) and transfer modes (MAG-CC, MAG-STT and MAG-CW) on distortion values. All of the welds were performed with ER70S-6 wire and pure CO₂ shielding gas in the short-circuit mode. It was observed that the most important variable was change of welding direction, which is directly connected to restriction levels of the test panel. The sequences used showed little effect on the distortion values. The reverse pass had low distortion values, yet was unproductive. It was observed that the distortion values were similar for the processes and MAG-STT. The panels welded by the MAG-CW process obtained the lowest distortion values measured.     

The Influence of Calcite,Fluorite, and Rutile on the Fusion-Related Behavior of Metal Cored Coated Electrodes for Hardfacing

Coated electrodes for SMAW have exhibited their advantages for longer than one century. Means of boosting their performance, particularly for hardfacing, would be a raise in the alloying transfer efficiency and a lowering of the dilution with the substrate, without losing the production capacity. In this study, an evaluation about the operational behavior of a new conception of electrodes for hardfacing is described, i.e., metal cored coated electrodes. Experimental electrodes were produced using metal cored technique to obtain the rods. FeCrMn was used as alloying material at two grain sizes. Using the Mc Lean Anderson experimental design approach, the content ratio of CaCO₃:CaF₂:TiO₂ in the coating was varied. The effect of the coating composition and granulometry of the filling alloying material on the formation a cannon-like end was assessed. Fusion and metal transfer behaviors were evaluated through measurements of fusion and deposition rates, deposition efficiency, and duration and frequencies of short-circuiting. Based on a balance of performances, the most appropriate composition for the coating was determined. It was also observed that a coarser FeCrMn presented better performance.     

Phenolic composition and antioxidant activity of Rocha pear and other pear cultivars – A comparative study

The phenolic profile and the antioxidant activity of Rocha pear, a Portuguese pear cultivar, were determined and compared with the commercially available pear varieties Comice, Abate, General Leclerc and Passe Crassane. Phenolic composition of the methanolic extracts of these pears was determined by high performance liquid chromatography with diode array detection (HPLC-DAD), while antioxidant activities were evaluated using three complementary test systems: DPPH radical scavenging activity, ferric reducing power capacity and β-carotene/linoleic acid bleaching assay. When compared to the studied varieties, Rocha pear (peel and flesh) presented the highest content of total phenolics. Among them, chlorogenic, syringic, ferulic and coumaric acids, arbutin and (?)-epicatechin were detected as major components. In addition, among the tested varieties, Rocha pear presented the best antioxidant activities in the DPPH and ferric reducing power assays.