Periodic Chaotic Billiards: Quantum-Classical Correspondence in Energy Space

We investigate the properties of eigenstates and local density of states (LDOS) for a periodic 2D rippled billiard, focusing on their quantum-classical correspondence in energy representation. To construct the classical counterparts of LDOS and the structure of eigenstates (SES), the effects of the boundary are first incorporated (via a canonical transformation) into an effective potential, rendering the one-particle motion in the 2D rippled billiard equivalent to that of two-interacting particles in 1D geometry. We show that classical counterparts of SES and LDOS in the case of strong chaotic motion reveal quite a good correspondence with the quantum quantities. We also show that the main features of the SES and LDOS can be explained in terms of the underlying classical dynamics, in particular of certain periodic orbits. On the other hand, statistical properties of eigenstates and LDOS turn out to be different from those prescribed by random matrix theory. We discuss the quantum effects responsible for the non-ergodic character of the eigenstates and individual LDOS that seem to be generic for this type of billiards with a large number of transverse channels.Comment: 13 pages, 18 figure

A semiquantal approach to finite systems of interacting particles

A novel approach is suggested for the statistical description of quantum systems of interacting particles. The key point of this approach is that a typical eigenstate in the energy representation (shape of eigenstates, SE) has a well defined classical analog which can be easily obtained from the classical equations of motion. Therefore, the occupation numbers for single-particle states can be represented as a convolution of the classical SE with the quantum occupation number operator for non-interacting particles. The latter takes into account the wavefunctions symmetry and depends on the unperturbed energy spectrum only. As a result, the distribution of occupation numbers $n_s$ can be numerically found for a very large number of interacting particles. Using the model of interacting spins we demonstrate that this approach gives a correct description of $n_s$ even in a deep quantum region with few single-particle orbitals.Comment: 4 pages, 2 figure

Penilaian Sistem Proteksi dan Kesesuaian Jalur Evakuasi Kebakaran pada Gedung PPAG 2 Universitas Katolik Parahyangan

Peraturan Menteri Pekerjaan Umum dan Perumahan Rakyat No. 19 Tahun 2018 mengamanatkan bahwa sebuah bangunan gedung wajib memiliki Sertifikat Laik Fungsi (SLF). Persyaratan SLF itu sendiri mewajibkan setiap bangunan gedung memenuhi empat aspek keandalan yaitu, keselamatan, kesehatan, kenyamanan, dan kemudahan. Penelitian terkait SLF ini dilakukan pada Gedung PPAG-2 Universitas Katolik Parahyangan yang meninjau dua dari empat persyaratan tersebut yaitu syarat keselamatan dan kemudahan bagi pengguna ketika terjadi bahaya kebakaran pada gedung. Pembahasan meliputi hasil identifikasi persyaratan penyediaan Sistem Proteksi Pasif, Sistem Proteksi Aktif, Sistem Evakuasi Darurat, Sarana Penyelamatan, dan Manajemen Keselamatan Kebakaran Gedung (MKKG) pada gedung. Berdasarkan hasil identifikasi didapati bahwa terdapat persyaratan sistem proteksi hanya sistem proteksi aktif dan persyaratan evakuasi yang tidak mencapai 100%. Sistem proteksi aktif dan persyaratan evakuasi secara berturut-turut mencapai angka 95% dan 96%

A combinatorial smoothness criterion for spherical varieties

We suggest a combinatorial criterion for the smoothness of an arbitrary spherical variety using the classification of multiplicity-free spaces, generalizing an earlier result of Camus for spherical varieties of type $A$.Comment: 14 pages, 2 table

Chaotic Waveguide-Based Resonators for Microlasers

We propose the construction of highly directional emission microlasers using two-dimensional high-index semiconductor waveguides as {\it open} resonators. The prototype waveguide is formed by two collinear leads connected to a cavity of certain shape. The proposed lasing mechanism requires that the shape of the cavity yield mixed chaotic ray dynamics so as to have the appropiate (phase space) resonance islands. These islands allow, via Heisenberg's uncertainty principle, the appearance of quasi bound states (QBS) which, in turn, propitiate the lasing mechanism. The energy values of the QBS are found through the solution of the Helmholtz equation. We use classical ray dynamics to predict the direction and intensity of the lasing produced by such open resonators for typical values of the index of refraction.Comment: 5 pages, 5 figure

Influence of a dynamical gluon mass in the pppp and pˉp\bar{p}p forward scattering

We compute the tree level cross section for gluon-gluon elastic scattering taking into account a dynamical gluon mass, and show that this mass scale is a natural regulator for this subprocess cross section. Using an eikonal approach in order to examine the relationship between this gluon-gluon scattering and the elastic $pp$ and $\bar{p}p$ channels, we found that the dynamical gluon mass is of the same order of magnitude as the {\it ad hoc} infrared mass scale $m_{0}$ underlying eikonalized QCD-inspired models. We argue that this correspondence is not an accidental result, and that this dynamical scale indeed represents the onset of non-perturbative contributions to the elastic hadron-hadron scattering. We apply the eikonal model with a dynamical infrared mass scale to obtain predictions for $\sigma_{tot}^{pp,\bar{p}p}$, $\rho^{pp,\bar{p}p}$, slope $B^{pp,\bar{p}p}$, and differential elastic scattering cross section $d\sigma^{\bar{p}p}/dt$ at Tevatron and CERN-LHC energies.Comment: 20 pages, 5 figures; misprints corrected and comments added. To appear in Phys. Rev.

Medicinal Plant Extracts and Their Use As Wound Closure Inducing Agents

Skin insult and damage start a complex healing process that involves a myriad of coordinated reactions at both the cellular and molecular level occurring simultaneously. These processes can be divided into that of cell migration and tissue remodeling of the wound. In addition, it is well known that deep wounds that derive from surgical procedures need a multidisciplinary approach to have a successful wound healing process. Recently, there has been a renowned interest in the identification of active compounds derived from ornamental, edible, and wild plants being used in the cosmetic and skin product industry. Recent reports suggest that active components of several plants such as Propolis and Aloe vera could be used to induce the process of wound healing and tissue regeneration and reducing therefore the time to complete wound closure. Other plant species such as Achillea millefolium or Salvia officinalis have anti-inflammatory properties and promote cellular proliferation contributing to faster tissue regeneration. It has been described that Malva sylvestris influences the formation of fibrosis-free granulation tissue in the skin. Recent observations suggest that Casearia sylvestris induces the angiogenic process. These effects have been evaluated in cell lines, different animal models, and some in randomized clinical trials. In this review we summarize the evidence of plant extracts and their active components (when known) in the acceleration of the wound closure process and tissue repair

Neonatal spontaneous biliary perforation: Case report

AbstractObjectiveSpontaneous biliary perforation in neonates is rare. The etiology of this pathology is idiopathic and various management strategies ranging from non-operative treatment to complex operations, such as biliary-enteric reconstruction, are performed, with few reported outcomes.Case reportA 3-week-old female, born at term, presented fever, abdominal distension, and acholic stool. An ultrasound was performed, which revealed generalized ascites and a poorly-defined collection. An emergency laparotomy confirmed perforation in the distal common bile duct and a biliary-enteric-anastomosis was performed.DiscussionWide drainage has been reported as the best initial management strategy for spontaneous biliary perforation, although it depends on the patient's clinical status and intraoperative findings.ConclusionsSpontaneous infantile biliary perforation is rare. Main management is wide drainage with, most perforations being resolved in 2 weeks

First Measurement of the He3+He3-->He4+2p Cross Section down to the Lower Edge of the Solar Gamow Peak

We give the LUNA results on the cross section measurement of a key reaction of the proton-proton chain strongly affecting the calculated neutrino luminosity from the Sun: He3+He3-->He4+2p. Due to the cosmic ray suppression provided by the Gran Sasso underground laboratory it has been possible to measure the cross section down to the lower edge of the solar Gamow peak, i.e. as low as 16.5 keV centre of mass energy. The data clearly show the cross section increase due to the electron screening effect but they do not exhibit any evidence for a narrow resonance suggested to explain the observed solar neutrino flux.Comment: 5 pages, RevTeX, and 2 figures in PostScript Submitted for publicatio