Modal analysis of wave propagation in dispersive media

Surveys on wave propagation in dispersive media have been limited since the pioneering work of Sommerfeld [Ann. Phys. 349, 177 (1914)] by the presence of branches in the integral expression of the wave function. In this article, a method is proposed to eliminate these critical branches and hence to establish a modal expansion of the time-dependent wave function. The different components of the transient waves are physically interpreted as the contributions of distinct sets of modes and characterized accordingly. Then, the modal expansion is used to derive a modified analytical expression of the Sommerfeld precursor improving significantly the description of the amplitude and the oscillating period up to the arrival of the Brillouin precursor. The proposed method and results apply to all waves governed by the Helmholtz equations.Comment: 10 pages, 9 figure

An Exactly Solvable Supersymmetric Model of Semimagic Nuclei

A simple model of nucleons coupled to angular momentum zero (s-pairs) occupying the valance shell of a semi-magic nuclei is considered. The model has a separable, orbit dependent pairing interaction which dominates over the kinetic term. It is shown that such an interaction leads to an exactly solvable model whose (0+) eigenstates and energies can be computed very easily with the help of the algebraic Bethe ansatz method. It is also shown that the model has a supersymmetry which connects the spectra of some semimagic nuclei. The results obtained from this model for the semimagic Ni isotopes from 58Ni to 68Ni are given. In addition, a new and easier technique for calculating the energy eigenvalues from the Bethe ansatz equations is also presented.Comment: Talk given at the International Conference on Nuclear Physics and Astrophysics: From Stable Beams to Exotic Nuclei, Cappadocia, June 200

Surgical treatment of giant cardiac aneurysm with pseudoaneurysm in a colon carcinoma patient

Left ventricular pseudoaneurysm is a rare and lethal condition associated with a high risk of rapid enlargement and rupture. It develops after transmural myocardial infarction (MI), cardiac surgery, trauma, or infection. When a left ventricular pseudoaneurysm is detected, surgical repair is recommended due to the high possibility of rupture. In this report, we present surgical treatment of a giant cardiac pseudoaneurysm that occurred after MI in a colon carcinoma patient

Classical Strongly Coupled QGP: VII. Energy Loss

We use linear response analysis and the fluctuation-dissipation theorem to derive the energy loss of a heavy quark in the SU(2) classical Coulomb plasma in terms of the $l=1$ monopole and non-static structure factor. The result is valid for all Coulomb couplings $\Gamma=V/K$, the ratio of the mean potential to kinetic energy. We use the Liouville equation in the collisionless limit to assess the SU(2) non-static structure factor. We find the energy loss to be strongly dependent on $\Gamma$. In the liquid phase with $\Gamma\approx 4$, the energy loss is mostly metallic and soundless with neither a Cerenkov nor a Mach cone. Our analytical results compare favorably with the SU(2) molecular dynamics simulations at large momentum and for heavy quark masses.Comment: 18 pages, 15 figures. v2: added references, changed title, replaced figures for Fig. 7, corrected typo

Self-force and synchrotron radiation in odd space-time dimensions

Classical electrodynamics in flat 3+1 space-time has a very special retarded propagator delta(x^2) localized on the light cone, so that a particle does not interact with its past field. However, this is an exception, and in flat odd-dimensional space-times as well as generic curved spaces this is not so. In this work we show that the so called self-force is not only non-zero, but it matches (in 2+1 dimensions) the radiation reaction force derived from the radiation intensity.Comment: 9 pages, 1 figur

Analisis Faktor Produksi Jaring Insang Lingkar (Encircling Gill Net) Di Ppi Pulolampes, Brebes

Jaring insang lingkar (koncong) menjadi alat tangkap dominan ke dua di PPI Pulolampes Brebes, keberadaanya semakin ditinggalkan karena kalah saing jumlah hasil target tangkapan yang sama dengan pukat cincin mini yang menjadi andalan masyarakat setempat. Pukat cincin mini memiliki tingkat selektifitas yang rendah dibandingkan jaring koncong, sedangkan penelitian terdahulu menunjukkan terjadi kecenderungan overfishing di perairan Brebes. Untuk meningkatkan hasil tangkapan jaring insang lingkar secara tepat dibutuhkan penelitian lebih lanjut tentang faktor faktor yang mempengaruhi produksi, serta menentukan model hubungan faktor produksi dengan pendekatan fungsi Cobb-Douglass. Penelitian dilaksanakan di PPI Pulolampes, Bulakamba Brebes pada bulan November 2015 – Januari 2016. Faktor yang diduga berpengaruh ialah panjang alat tangkap, lebar alat tangkap, ukuran perahu, kekuatan mesin, lama trip, jumlah BBM, jumlah ABK, dan pengalaman nelayan. Hasil analisis dengan menggunakan uji t menunjukkan bahwa faktor produksi yang berpengaruh dengan taraf nyata 95% ialah panjang alat tangkap, lama trip, jumlah BBM, jumlah ABK dan umur kerja. Hasil penelitian menunjukkan tidak semua faktor berpengaruh positif terhadap hasil tangkapan, disimpulkan panjang alat tangkap memiliki pengaruh negatif terhadap hasil produksi. Sedangkan faktor yang paling dominan terhadap peningkatan hasil produksi ialah jumlah BBM. Dari hasil analisis statstika tersebut dapat disimpulkan, peningkatan produksi dicapai jika jarak fishing ground, jumlah ABK dan pengalaman kerja nelayan ditingkatkan. Tetapi panjang alat tangkap diberi ketentuan maksimum. Encircling Gill Net become one of two dominant fishing gear in Coastal Fishing Port Pulolampes Brebes, its existence being abandoned because of less competitive hauling number than the fishing gear mainstay of a local community, which is Mini purse sein. Unfortunately, Mini Purse Sein has a low standard of selectivity compared to Encircling Gill Net, whereas previous studies showed a trend towards overfishing in the waters of Brebes. To increase optimality of gill net hauling number, this research aims to analysis factors that affecting production, as well as determining production factors relationship model with Cobb-Douglass function approach. Research located at the Coastal Fishing Port Pulolampes, Bulakamba in November 2015 - January 2016. There\u27s eight factors thought to affect fishing gear, such as Gill Net length, Gill Net-wide, vessel dimension, engine power, a length of trip, amount of fuel, the number of crews, and fisherman work experience. The results of analysis using the t test showed that the production of factors affect 95% of the production are Gill Net length, amount of fuel, the number of crew and fisherman work experience. The results showed that not all factors positively affects the catch, the length of fishing gear have a negative effect on production. While the most dominant factor whose increasing the production is the amount of fuel. From the statistic analysis, it can be concluded, to increasing the production is achieved if the distance fishing ground, the number of crew and the fishing improved work experience. But Gill Net length ought to give maximum provision