Thermal-dynamic modeling study

Study provides basic information for designing models and conducting thermal-dynamic structural tests. Factors considered are development and interpretation of thermal-dynamic structural scaling laws; identification of major problem areas; and presentation of model fabrication, instrumentation, and test procedures

Loyalty discounts

This paper considers the use of loyalty inducing discounts in vertical supply chains. An upstream manufacturer and a competitive fringe sell differentiated products to a retailer who has private information about the level of stochastic demand. We provide a comparison of market outcomes when the manufacturer uses two-part tariffs (2PT), all-unit quantity discounts (AU), and market share discounts (MS). We show that retailer's risk attitude affects manufacturer's preferences over these three pricing schemes. When the retailer is risk-neutral, it bears all the risk and all three schemes lead to the same outcome. When the retailer is risk-averse, 2PT performs the worst from manufacturer s perspective but it leads to the highest total surplus. For a wide range of parameter values (but not for all) the manufacturer prefers MS to AU. By limiting the retailer's product substitution possibilities MS makes the demand for manufacturer s product more inelastic. This reduces the amount (share of total profits) the manufacturer needs to leave to the retailer for the latter to participate in the scheme.This study is funded from the Valencian Economic Research Institute (IVIE) and the European Commission

Modal sensitivity for structural systems with repeated frequencies

Repeated or closely packed modal frequencies are common physical occurrences for vibrating structures which are complex or possess multi-planes of symmetry. The computation of the sensitivity to structural modifications for these frequencies and mode shapes is made difficult by the fact that the mode shapes are not unique, since any linear combination of eigenvectors corresponding to a repeated eigenvalue is also an eigenvector. The work of Chen and Pan is extended, who used modal expansion techniques for accommodating the sensitivity analysis of structures with repeated eigenvalues. Starting with a discussion of the physical significance of sensitivity analysis for repeated frequency modes, a derivation is presented of the governing equations for the derivatives of a repeated eigenvalue. This is followed with a small example to illustrate the results. An efficient computation procedure, based upon an expansion of Nelson's ideas for large banded systems, is then proposed for systems with repeated or closely spaced eigenvalues

Pembuatan detektor Sinar-X Isisan Gas jenis proporsional Tipe Jendela samping

Telah dibuat dan diteliti detektor proporsional tripe jendela samping dengan gas isian argon dan metana Tekanan total gas isian adalah 400 mmHg dengan perbandingan tekanan 95 : 5. Katoda terbuat clari stainless steel berdiameter 24,2 mm dengan panjang 100mm dan anoda dari tungsten berdiameter 0,08 mm. Jendela terbuat dari berilium, dengan panjang 24 mm dan lebar 12 mm. Dari pengujian detektor diperoleh bahwa tegangan ambang 2200 volt, plats 125 volt, slope 2,3%/100 volt, resolusi energi 11,66 % dan efisiensi 8,57 % terhadap sinar-X dengan somber Fels pada jarak 0 mm. A side window proportional counter has been made and observed. Argon and methane with the total pressure of 400 mmHg and the pressure ratio of 95 ; 5 are used as a filled gas. The cathode with diameter of 24,2 mm, length of 100 mm and anode with diameter of 0,08 mm made of stainless steel and tungsten respectively are used in this experiment. Beryllium with length of 24 mm and width of 12 mm is used as a window. The performance test of this detector shows that the treshold voltage , plateau, slope, energy resolution and efficiency for X-ray with Fe55 as a radiation source at 0 mm are 2200 volt, 125 volt, 2,3%/100 volt, 11,66 % and 8,57 % respectively

Ricci Collineations of the Bianchi Types I and III, and Kantowski-Sachs Spacetimes

Ricci collineations of the Bianchi types I and III, and Kantowski-Sachs space- times are classified according to their Ricci collineation vector (RCV) field of the form (i)-(iv) one component of $\xi^a (x^b)$ is nonzero, (v)-(x) two components of $\xi^a (x^b)$ are nonzero, and (xi)-(xiv) three components of $\xi^a (x^b)$ are nonzero. Their relation with isometries of the space-times is established. In case (v), when $det(R_{ab}) = 0$, some metrics are found under the time transformation, in which some of these metrics are known, and the other ones new. Finally, the family of contracted Ricci collineations (CRC) are presented.Comment: 21 Pages, LaTeX, no figures, accepted for publication in the International Journal of Modern Physics

Geometric Models of the Quantum Relativistic Rotating Oscillator

A family of geometric models of quantum relativistic rotating oscillator is defined by using a set of one-parameter deformations of the static (3+1) de Sitter or anti-de Sitter metrics. It is shown that all these models lead to the usual isotropic harmonic oscillator in the non-relativistic limit, even though their relativistic behavior is different. As in the case of the (1+1) models, these will have even countable energy spectra or mixed ones, with a finite discrete sequence and a continuous part. In addition, all these spectra, except that of the pure anti-de Sitter model, will have a fine-structure, given by a rotator-like term.Comment: 8 pages, Late

Geometric Models of the Relativistic Harmonic Oscillator

A family of relativistic geometric models is defined as a generalization of the actual anti-de Sitter (1+1) model of the relativistic harmonic oscillator. It is shown that all these models lead to the usual harmonic oscillator in the non-relativistic limit, even though their relativistic behavior is quite different. Among quantum models we find a set of models with countable energy spectra, and another one having only a finite number of energy levels and in addition a continuous spectrum.Comment: 8 pages, Late