Soil Improvement for Storage Tank Foundations

Three 30,000m3 storage tanks are located at a hydraulic-filled reclamation site and close to an earthquake active area in Taiwan. In order to reduce the risk of liquefaction in loose silty sand of foundations, the soil improvement methods of both dynamic compaction and vibro-replacement stone column are applied. One storage tank foundation was improved using vibro-replacement stone column approach only, and the treatment pattern consisted of stone columns on a triangular grid arrangement with three spacing patterns. A combination of the dynamic compaction and vibro-replacemenr stone column technique was utilized on foundations of the others. The dynamic compaction was performed at two different storage tank foundations with two types of impact energy first, then vibro-replacement stone column technique was carried out. To understand the effect of time on soil strength after soil improvement, CPT soundings were frequently performed at short interval time. It was found from results of CPT that soil strength increased with decreasing spacing of stone columns and increasing dynamic compaction impact energy. But during the short period of time after improvement, soil strength has no obvious change with time

Nonclassicality of Thermal Radiation

It is demonstrated that thermal radiation of small occupation number is strongly nonclassical. This includes most forms of naturally occurring radiation. Nonclassicality can be observed as a negative weak value of a positive observable. It is related to negative values of the Margenau-Hill quasi-probability distribution.Comment: 3 pages, 3 figure

Prescribing pattern of antidepressants in psychiatric unit of a tertiary care hospital

Background: The objective was to study the prescribing pattern of antidepressants in psychiatric unit of a tertiary care hospital.Methods: An observational study was carried out at psychiatry out-patient department (OPD). The data which were collected included information about age, gender, education, occupation, marital status and drug prescription included trade name, generic name, dosage, and frequency of 100 outpatients who attended the psychiatry OPD.Results: Among 100 patients with major depression 66% were females and 34% were males. Depression was more commonly seen between patients with age group 21-40 years. Depression was more common among housewives (44%) and next was students (18%). Percentage of depression was more in educated people with (72%) than in uneducated with (28%). Depression was more commonly seen in married people with (77%) than in unmarried people (23%). Most commonly prescribed antidepressant as monotherapy was fluoxetine and as combination therapy was fluoxetine and escitalopram.Conclusions: Depression is more commonly seen in married people predominantly in females and housewives. Fluoxetine is more commonly used followed by escitalopram. Selective serotonin reuptake inhibitors are preferred over other antidepressant because of their relative lesser side effects

Perturbative Hamiltonian constraints for higher order theories

We present a method for constructing a consistent low energy canonical formalism for higher order time-derivative theories, extending the Dirac method to include perturbative Hamiltonian constraints. We apply it to two paradigmatic examples: the Pais-Uhlenbeck oscillator and the Bernard-Duncan scalar field. We also compare the results, both at the classical and quantum level, with the ones corresponding to a direct perturbative construction applied to the exact higher order theory. This comparison highligths the soundness of the present formalism.Comment: 26 pages, 4 figures; review section shortened and appendices change

Rotations associated with Lorentz boosts

It is possible to associate two angles with two successive non-collinear Lorentz boosts. If one boost is applied after the initial boost, the result is the final boost preceded by a rotation called the Wigner rotation. The other rotation is associated with Wigner's O(3)-like little group. These two angles are shown to be different. However, it is shown that the sum of these two rotation angles is equal to the angle between the initial and final boosts. This relation is studied for both low-speed and high-speed limits. Furthermore, it is noted that the two-by-two matrices which are under the responsibility of other branches of physics can be interpreted in terms of the transformations of the Lorentz group, or vice versa. Classical ray optics is mentioned as a case in point.Comment: LaTeX, 16 Pages, 4 epsfigure

Iwasawa Effects in Multi-layer Optics

There are many two-by-two matrices in layer optics. It is shown that they can be formulated in terms of a three-parameter group whose algebraic property is the same as the group of Lorentz transformations in a space with two space-like and one time-like dimensions, or the $Sp(2)$ group which is a standard theoretical tool in optics. Among the interesting mathematical properties of this group, the Iwasawa decomposition drastically simplifies the matrix algebra under certain conditions, and leads to a concise expression for the S-matrix for transmitted and reflected rays. It is shown that the Iwasawa effect can be observed in multi-layer optics, and a sample calculation of the S-matrix is given.Comment: RevTex 10 pages including 1 psfi

Recursive Construction of Generator for Lagrangian Gauge Symmetries

We obtain, for a subclass of structure functions characterizing a first class Hamiltonian system, recursive relations from which the general form of the local symmetry transformations can be constructed in terms of the independent gauge parameters. We apply this to a non-trivial Hamiltonian system involving two primary constraints, as well as two secondary constraints of the Nambu-Goto type.Comment: 10 pages, Late

Factorisation of analytic representations in the unit disk and number-phase statistics of a quantum harmonic oscillator

The inner-outer part factorisation of analytic representations in the unit disk is used for an effective characterisation of the number-phase statistical properties of a quantum harmonic oscillator. It is shown that the factorisation is intimately connected to the number-phase Weyl semigroup and its properties. In the Barut-Girardello analytic representation the factorisation is implemented as a convolution. Several examples are given which demonstrate the physical significance of the factorisation and its role for quantum statistics. In particular, we study the effect of phase-space interference on the factorisation properties of a superposition state.Comment: to appear in J. Phys. A, LaTeX, 13 pages, no figures. More information on http://www.technion.ac.il/~brif/science.htm

Analytic representations based on SU(1,1) coherent states and their applications

We consider two analytic representations of the SU(1,1) Lie group: the representation in the unit disk based on the SU(1,1) Perelomov coherent states and the Barut-Girardello representation based on the eigenstates of the SU(1,1) lowering generator. We show that these representations are related through a Laplace transform. A ``weak'' resolution of the identity in terms of the Perelomov SU(1,1) coherent states is presented which is valid even when the Bargmann index $k$ is smaller than one half. Various applications of these results in the context of the two-photon realization of SU(1,1) in quantum optics are also discussed.Comment: LaTeX, 15 pages, no figures, to appear in J. Phys. A. More information on http://www.technion.ac.il/~brif/science.htm

Semiquantal dynamics of fluctuations: Ostensible quantum chaos

The time-dependent variational principle using generalized Gaussian trial functions yields a finite dimensional approximation to the full quantum dynamics and is used in many disciplines. It is shown how these 'semi-quantum' dynamics may be derived via the Ehrenfest theorem and recast as an extended classical gradient system with the fluctuation variables coupled to the average variables. An extended potential is constructed for a one-dimensional system. The semiquantal behavior is shown to be chaotic even though the system has regular classical behavior and the quantum behavior had been assumed regular.Comment: 9 pages, TeX, 2 figures (not attached; hard copies available immediately on request). To appear in Physical Review Letter