Vertices and the CJT Effective Potential

The Cornwall-Jackiw-Tomboulis effective potential is modified to include a functional dependence on the fermion-gauge particle vertex, and applied to a quark confining model of chiral symmetry breaking.Comment: 10 pages (latex), PURD-TH-93-1

Logical Pluralism: Where the Conflict Really Lies

Recent years have seen a surge of attention to the problem of logical pluralism; most of which has been a reaction to Beall and Restall’s account of logical pluralism as the existence of more than one equally correct semantic relation of logical consequence. The underlying thesis is that the indeterminacy of the notion of validity goes beyond what the inductive-deductive distinction can precisify. The notion of deductive validity itself is indeterminate as well and this indeterminacy has its roots in the indeterminacy of the more fundamental notion of case. Cases are what make the premisses and the conclusion of an argument true; the most notable example being Tarskian models for classical logic. Deductive validity is the preservation of truth across all cases. This paper argues that unless this account of logical pluralism is supplemented with an argument in favor of the equal legitimacy of the purported cases it becomes merely a semi-controversial exposition of how different logics can be generated

Strong Structural Controllability of Signed Networks

In this paper, we discuss the controllability of a family of linear time-invariant (LTI) networks defined on a signed graph. In this direction, we introduce the notion of positive and negative signed zero forcing sets for the controllability analysis of positive and negative eigenvalues of system matrices with the same sign pattern. A sufficient combinatorial condition that ensures the strong structural controllability of signed networks is then proposed. Moreover, an upper bound on the maximum multiplicity of positive and negative eigenvalues associated with a signed graph is provided

Kajian Sistem Transitivitas pada Teks Surat Al Insan sebagai Wujud Identitas Budaya dalam Membangun Karakter Bangsa

The main issues that were examined in this study is the transitivity system in the text of the letter Al Insan as an expression of cultural identity in building the nation's character. Based on the logic problem in this research is to determine the type of process that dominates, to determine the form of identity in building the nation's character. The approach used in this study is a qualitative descriptive theory based on Systemic Functional Linguistics. Methods of data collection is done through documentation, and technical notes. The analyzing of the data was performed using the clause identifying and analyzing the results of the data using the method descriptions, outlines and describes the data that has been collected. The findings show that the system of transitivity in translation text surah Al Insan many as 27 process material (46.55%), 9 (15:52%) of mental processes, 10 (17:24%) the relational, 2 (3:45%) process behavior, 1 (1.72% ) verbal process, and the form of 1 (1.72%). The emergence of the dominant system of transitivity on text translation text surah Al Insan as a form of a command, restrictions and instructions shown to man as consciousness in cultured and effort in changing the human personality, the man made consistent with the character of the nation

Optimisation of blade type spreaders for powder bed preparation in additive manufacturing using DEM simulations

Powders used in the Particle Bed Fusion process are spread onto compact layers and then are fused to generate a layer of the final part. This process is repeated layer-upon-layer to form the final products. It has recently been demon- strated [Powder Technology, 306 (2017) 45–54] that spreading the particles with a counter-rotating roller produces a bed with a higher quality (i.e. a lower void fraction) compared to a blade type spreader. This is related to the geometry of the two spreaders which directly changes the bed-spreader contact dynamic and consequently affects the bed's quality. Based on this rationale, here, it is postulated that changing the blade profile at the blade bed contact region can significantly enhance the bed's quality and improve the effectiveness of a blade as a spreading device. A set of Discrete Element Method (DEM) simulations is performed at device-scale to optimise the geometry of blade spreaders to yield the lowest void fraction using simple rod-shaped grains to control the computational costs. The blade profile is parametrised using a super-ellipse with three geometrical parameters. Firstly, it is demonstrated that geometric optimisation of a blade profile is an effective alternative to using more complex spreading devices. Secondly, for the proposed parametrisation, the optimum values are found using computer simulations and it is shown that bed volume fractions close to critical values are achievable. Finally, a new technique for multi-sphere approximation (MSA) is developed and applied to 3D models of real powder grains to generate realistic particle shapes for the DEM simulations. Then using these grains it is shown that the proposed optimum blade profile is capable of producing a bed with qualities comparable (and even better) to a roller at the actual operating conditions and with realistic grain characteristics