Características biológicas de Rhipicephalus (Boophilus) microplus mantidos em novilhas naïve da raça Angus.

SIEPE

Reciprocating wear tests of Al–Si/SiCp composites: a study of the effect of stroke length

The aim of the work described here was to find evidence for the influence of stroke length on the reciprocating wear of aluminium matrix composites. For this purpose, two kinds of tests were performed: reciprocating ball-on-plane geometry experiments to apply stroke in the millimetre range, and fretting tests to study the strokes in the micrometer scale. The relationships between the dissipated energy and the wear volume were established to compare these two different scale tests. The results are discussed in terms of energy approach and of the comparison of the wear mechanisms observed on the wear scars resulting from both tests

Pertumbuhan Alga Cokelat Padina Australis Hauch Di Perairan Pesisir, Desa Kampung Ambon, Kecamatan Likupang Timur, Kabupaten Minahasa Utara

Alga laut adalah bagian terbesar dari tumbuhan laut, namun dari segi morfologi tumbuhan ini mempunyai perbedaan dengan tumbuhan-tumbuhan yang ada di daratan. Alga merupakan tumbuhan tingkat rendah yang tidak memiliki perbedaan susunan kerangka seperti alat pelekat (holdfast), batang (stipe) dan daun (blade) meskipun wujudnya tampak seperti ada perbedaan, tetapi sesungguhnya merupakan bentuk thallus belaka. Pemanfaatan rumput laut di Indonesia sendiri dimulai sejak tahun 1920 yang digunakan secara tradisional sebagai makanan seperti lalap, sayur dan manisan. Akan tetapi dengan berkembangnya ilmu pengetahuan, pemanfaatan alga laut ke arah komersial untuk diekspor semakin meningkat. Hal ini dikarenakan kandungan kimia yang terdapat dalam alga laut seperti agar dan karaginan yang terdapat pada alga merah, algin pada alga cokelat serta alga hijau yang merupakan sumber karbonat. Salah satu jenis alga laut cokelat yaitu Padina. Pada tahun 2014, telah dikembangkan produk anti-ageing oleh PT APRO yang bekerja sama dengan CEVA (Centre d‟Etude et de Valorisation des Algues) di Pleubian, Perancis yang berasal dari Padina australis yang dipanen dari Kawasan Timur Indonesia. Tujuan penelitian ini adalah untuk melihat pertumbuhan alga cokelat Padina australis untuk menentukan waktu panen yang tepat untuk pengembangan budidaya

Term Structure Models with Shot-noise Effects

This work proposes term structure models consisting of two parts: a part which can be represented in exponential quadratic form and a shot noise part. These term structure models allow for explicit expressions of various derivatives. In particular, they are very well suited for credit risk models. The goal of the paper is twofold. First, a number of key building blocks useful in term structure modelling are derived in closed-form. Second, these building blocks are applied to single and portfolio credit risk. This approach generalizes Duffie & Garleanu (2001) and is able to produce realistic default correlation and default clustering. We conclude with a specific model where all key building blocks are computed explicitly

Effect of heterogeneity on the elastic properties of auxetic materials

Copyright © 2003 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 94 (2003) and may be found at http://link.aip.org/link/?jap/94/6143Auxetic materials are gaining practical interest for their unusual and sometimes extreme mechanical response. The process of modeling these materials so far has highlighted a number of microstructural properties that are key to these materials. However these models often rely on the assumption of homogeneity and order within the materials. Practically, a homogeneous auxetic material such as foam is unlikely to be manufactured. This work seeks to analyze the effect of fluctuations within the microstructure of the material. Numerical results show the effect of fluctuations in an auxetic granular substance and analytical work indicates the relation between microscale fluctuations and the elastic moduli for a general auxetic material

Survival estimates of bycatch individuals discarded from bivalve dredges

The fate of released bycatch is an issue of great interest for fisheries research and management. Survival experiments were carried out to assess the survival capacity of animals damaged and discarded during clam dredging operations. Three common bycatch species, two fish (Trachinus vipera; Dicologlossa cuneata) and one crab (Polybius henslowii), were collected during the sorting of catches from a commercial dredging boat. An arbitrary score scale was used to quantify the type and extent of damage to the organisms. Onboard, damaged individuals were placed in tanks containing seawater which were subsequently transferred to the laboratory. Survival experiments were conducted during the subsequent 48h. D. cuneata exhibited the lowest mortality after 48h (54%), followed by P. henslowii (65%) and T. vipera (81%). Despite the magnitude of the percentage mortalities determined, the average number of individuals estimated to die during a 15 minutes tow (standard commercial fishing time) was relatively small: 1.2, 3.24 and 11 for D. cuneata, T. vipera and P. henslowii, respectively. Nevertheless, when these figures are extrapolated to cover all the dredging fleet the impact of this practice on the populations of the species studied can be significant, particulary for D. cuneata

Stabilized vortex solitons in layered Kerr media

In this letter we demonstrate the possibility of stabilizing beams with angular momentum propagating in Kerr media. Large propagation distances without filamentation can be achieved in layered media with alternating focusing and defocusing nonlinearities. Stronger stabilization can be obtained with the addition of an incoherent beam.Comment: 4 pages, 3 figures. We have removed the sentence "Thus, they erroneously point out to the existence of fully stabilized vortex solitons" in page 2, column 2, line 7-8, because it might be confusin

Stabilization of high-order solutions of the cubic Nonlinear Schrodinger Equation

In this paper we consider the stabilization of non-fundamental unstable stationary solutions of the cubic nonlinear Schrodinger equation. Specifically we study the stabilization of radially symmetric solutions with nodes and asymmetric complex stationary solutions. For the first ones we find partial stabilization similar to that recently found for vortex solutions while for the later ones stabilization does not seem possible