Calculation of fin efficiency is necessary for the design heat exchangers. This can be calculated individual finned tubes or continuous fins. Continuous fins are mostly used in plate-fin and tube exchangers (PFTHEs). In most cases, basic elements those PFTHEs circular, oval flattened pipes, which contain circular polygonal fins, as observed PFTHEs, divided into virtual Those have a rectangular ...

0. Introduction 336 1. Main results 337 1.1. Semisimple groups 337 1.2. Factorization problem 338 1.3. Total positivity 339 1.4. Generalized minors 339 1.5. The twist maps 340 1.6. Formulas for factorization parameters 341 1.7. Total positivity criteria 343 1.8. Fundamental determinantal identities 343 2. Preliminaries 344 2.1. Involutions 344 2.2. Commutation relations 345 2.3. Generalized det...

Concepts of cardiac development have greatly influenced the description of the formation of the four-chambered vertebrate heart. Traditionally, the embryonic tubular heart is considered to be a composite of serially arranged segments representing adult cardiac compartments. Conversion of such a serial arrangement into the parallel arrangement of the mammalian heart is difficult to understand. L...

To realize a structure which can be conveniently tuned to multiple and wideband frequency ranges, geometrical-stiffening membrane acoustic metamaterial (MAM) with individually tunable frequencies is presented. The MAM realized by stacked arrangement of two membrane-magnet elements, each has small piece steel attached in the centre. It adjusting position its compact magnet. normal incidence soun...

Let V be Euclidean space. Let W ⊂ GL(V ) be a finite irreducible reflection group. Let A be the corresponding Coxeter arrangement. Let S be the algebra of polynomial functions on V. For H ∈ A choose αH ∈ V ∗ such that H = ker(αH). The arrangement A is known to be free: the derivation module D(A) = {θ ∈ DerS | θ(αH ) ∈ SαH} is a free S-module with generators of degrees equal to the exponents of ...

Motivated by a scheduling problem encountered in multicast environments, we study a vertex labelling problem, called Directed Circular Arrangement (DCA), that requires one to find an embedding of a given weighted directed graph into a discrete circle which would minimize the total weighted arc length. Its decision version is already known to be NP-complete when restricted to sparse weighted dir...

The effects of calibration phantoms on the correction results of the empirical artifacts correction method (ECCU) for the case of tube modulation were investigated. To improve the validity of the ECCU method, the effect of the geometry parameter of a typical single-material calibration phantom (water calibration phantom) on the ECCU algorithm was investigated. Dual-material calibration phantoms...

The paper describes the calculation of the reach sets and tubes for linear control systems with time-varying coefficients and ellipsoidal hard bounds on the controls and initial states. This is achieved by parametrized families of external and internal ellipsoidal approximations constructed such that they touch the reach sets at every point of their boundary at any instant of time (both from ou...