Necessity, a Leibnizian Thesis, and a Dialogical Semantics

In this paper, an interpretation of "necessity", inspired by a Leibnizian idea and based on the method of dialogical logic, is introduced. The semantic rules corresponding to such an account of necessity are developed, and then some peculiarities, and some potential advantages, of the introduced dialogical explanation, in comparison with the customary explanation offered by the possible worlds semantics, are briefly discussed

Experimental study of the turbulence structures in a boundary layer subjected to a strong adverse pressure gradient

L'objet de cette thèse porte sur la compréhension des structures cohérentes d'une couche limite turbulente soumise à un fort gradient de pression adverse, et qui a aussi subie une transition brusque de fort gradient de pression favorable à un gradient de pression adverse. L'installation expérimentale permet d'obtenir des conditions d'écoulement correspondant au décrochage d'une aile. De grands ensembles de champs de vitesse instantanée sont acquis par "Particle Image Velocimetry" dans des plans à la paroi alignés avec l'écoulement à trois positions différentes dans la direction de l'écoulement dans la région de gradient de pression défavorable. Les investigations sur les champs instantanés de vitesse prouvent que la région supérieure de la couche limite est densément peuplée avec des signatures de tourbillons hairpin et des paquets de hairpins qualitativement semblables à ceux rencontrées dans la couche limite turbulente à gradient de pression nul. Puisque les paquets de hairpin voyagent avec la petite dispersion de vitesse, les groupes de hairpin semblent être arrangés de façon cohérente dans la direction de l'écoulement. On constate que les paquets de hairpins se prolongent parfois au-delà d'une longueur de 2[delta] et contiennent 3 à 12 tourbillons. En plus, l'estimation stochastique linéaire et les corrélations spatiales entre l'intensité des tourbillons "pro-grade/prograde" indiquent également que les empreintes sont qualitativement semblables aux paquets de hairpin trouvés dans les champs instantanés. L'angle moyen de croissance des paquets de hairpin dans la direction de l'écoulement est approximativement 11°, ce qui est plus important que dans la couche limite turbulente à gradient de pression nul. Les hairpins individuels sont aussi légèrement plus inclinés par rapport à la paroi et plus rapprochés dans la couche limite turbulente avec gradient de pression adverse. Ces différences de propriétés de hairpin sont consistantes avec les différences de taux de déformations moyens dans les deux écoulements. L'intensité des têtes de hairpin normalisée par l'échelle de temps de Zagarola-Smits a une valeur plus élevée dans le cas à gradient de pression nul par rapport à l'écoulement présent et, dans la moitié inférieure de la couche limite diminue dans la direction de l'écoulement dans ce dernier. Tout proche de la paroi, la population de hairpins diminue dans la direction de l'écoulement, alors qu'elle augmente dans la région supérieure. Ces différentes tendances des populations et d'intensité de hairpin sont compatibles avec celles des tensions de Reynolds et de la production de turbulence. C'est également compatible aux résultats rapportés que des hairpins sont la source majeure de la production de turbulence. Finalement, la taille des tourbillons normalisée par l'épaisseur de la couche limite diminue légèrement dans la direction de l'écoulement. Puisque l'écoulement moyen évolue rapidement, il est donc possible que les structures turbulentes répondent avec un certain retard aux changements de l'écoulement moyen

On Kant and Husserl on Transcendental Logic

It is well known that the notion of transcendental logic has a prominent role in both Kant’s and Husserl’s theories of knowledge. The main aim of the present paper is to study the links between formal and transcendental logic in Husserl on the one hand, and the links between general logic and transcendental logic in Kant on the other. There is a debate about the proper relation between transcendental logic and general logic in Kant’s philosophy. By means of our definition of transcendental logic, mainly drawn from Husserl’s analyses, we will try to offer an appropriate interpretation of Kant’s view

Mechanical and dentin bond strength properties of the nanosilver enriched glass ionomer cement

The aim of this study was to investigate the mechanical properties and dentin microshear bond strength of a conventional glass ionomer cement (GIC) compared to GIC supplemented with silver nanoparticles (SNPs) at 0.1% and 0.2% (w/w). SNPs were incorporated into a conventional GIC at 0.1% and 0.2% (w/w). The unmodified GIC was used as the control group. Compressive strength, flexural strength, and micro-shear bond strength (µSBS) to dentin were evaluated using a universal testing machine. Surface microhardness was determined using a Vickers microhardness tester. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey?s test. GICs containing 0.1% and 0.2% (w/w) SNPs significantly improved compressive strength, surface microhardness, and dentin µSBS compared to the unmodified GIC (p<0.05). A significant increase in the flexural strength was found for the GIC containing 0.2% (w/w) SNPs (p<0.05). However, the GIC containing 0.1% (w/w) SNPs did not affect flexural strength. GIC supplemented with SNP is a promising material for restoration because of its improved mechanical and bond strength properties. Therefore, it may be suggested for use especially in higher stress-bearing site restorations

Factors Influencing Rural-Urban Migration from Mountainous Areas in Iran: A Case Study in West Esfahan

Migration of young people from rural areas reduces the rural development goals and increase social and economic problems in cities. This is an analysis of the causes of rural-urban migration from Esfahan Mountainous areas and guidelines for reducing migration from villages. Data were obtained using mixed methods approach comprising questionnaire surveys and key informant interviews. Study population are residents of 28 villages from Fereidan and Fereidunshahr counties. The population are 6300 people, who have migrated from these two counties. 362 persons were selected Using Cochran formula, as the sample size. Then, analysis was performed using SPSS v. 20 software. The study revealed that poverty, lack of jobs, insufficient educational facilities, education in the city, lack of public transportation systems, unsuitable mountain Road, cold weather , shortage of doctors, hospitals and health facilities are main factors of rural-urban migration from iran Mountainous areas. So It is recommended to eliminate the problems mentioned to reduce the rate of rural-urban migration for the rural residents

Study on probiotic potential of Bacillus species isolated from the intestine of farmed rainbow trout, Oncorhynchus mykiss

The gastrointestinal tract of fishes is a complex ecosystem occupied by a large number of microorganisms, some of them could have potentially-valuable features. This research was conducted to study Bacillus species in the intestine of farmed rainbow trout to examine their probiotic properties, and to provide a new source of probiotics. A total of 23 farmed rainbow trout were sampled and their intestine samples were cultured. Following the morphological assay and biochemical analysis, isolated Bacilli were amplified by polymerase chain reaction and universal primers 27f and 1492r. Bacillus subtilis and B. amyloliquefaciens were isolated from 5 and 3 samples, respectively. Bacillus tequilensis, B. cereus and B. licheniformis were isolated from 1 sample. Probiotic properties of B. subtilis strain MSM 24, B. amyloliquefaciens strain TMM 25 and B. licheniformis strain MR 78 were confirmed. Since probiotic bacteria cause no foodborne diseases, their existence in farmed trout intestines, and their penetration into the fish tissues do not pose any risk to consumers' health