The present paper describes the basic principles of acoustic emission (AE) tomography. This method uses acoustic emission events as point sources and combines the usual iterative localization algorithm of AE testing with algorithms for travel time tomography like ART (algebraic reconstruction technique). The procedure is equivalent to the solution of the generalized inverse localization problem...

Mismatches between the composition of a time-averaged death assemblage (dead remains sieved from the upper mixed-zone of the sedimentary column) and the local living community are typically attributed to natural postmortem processes. However, statistical analysis of 73 molluscan data sets from estuaries and lagoons reveals significantly poorer average "live-dead agreement" in settings of docume...

Let G be a graph and let T be a tree with the same vertex set. Let e be an edge of T and Ae and Be be the vertex sets of the components of T obtained after removal of e. Let EG(Ae, Be) be the set of edges of G with one endvertex in Ae and one endvertex in Be. Let ec(G : T ) := max e |EG(Ae, Be)|. The paper is devoted to minimization of ec(G : T ) • Over all trees with the same vertex set as G. ...

Carum copticum is a grassy and annual plant which is believed to have several therapeutic effects, including anti-asthmatic properties. We have therefore studied the bronchodilatory and anticholinergic effects of 4 rnL aqueous extract (AE), 0.0 5 mL ethanol extract (EE), and 0.0 0 5 mL essential oil (EO) of Carum copticum and 1 rnL of a 5 mM solution of its main ingredient, thymol (T), in ...

AE monitoring from various types of stress corrosion cracking (SCC) has been conducted for the past 15 years in our laboratory. This paper discusses AE results of active-path dissolution-type SCC of austenitic stainless steel in chloride solution and fused salt, fluoride and polythionic acid solutions, brass in ammonia (Mattosson's solution), and carbon steels in nitrite solution. Transgranular...

  In this study we investigated the bronchodilatory and anticholinergic effects of the aqueous extract (AE), brewed extract (BE) and ethanol extract (EE) of Polygonum avicular in comparison with saline (S) on isolated tracheal chains of the guinea pig. Due to the probable confounding effect of ethanol in the EE, the effects of this extract were also compared with 96 % ethanol. None of the plant...

Characterization of acoustic emission (AE) signals in loaded materials can reveal structural damage and consequently provide early warnings about product failures. Therefore, extraction the most informative features from AE is an important part characterization process. This study considers obtained bending experiments for carbon fiber epoxy (CFE) glass (GFE) composites. The research focused on...

The alternating evolution (AE) system of Liu [27] ∂tu+ ∂xf(v) = 1 (v − u), ∂tv + ∂xf(u) = 1 (u− v), serves as a refined description of systems of hyperbolic conservation laws ∂tφ+ ∂xf(φ) = 0, φ(x, 0) = φ0(x). The solution of conservation laws is precisely captured when two components take the same initial value as φ0, or approached by two components exponentially fast when ↓ 0 if two initial st...

The alternating evolution (AE) system of Liu [25] ∂tu +∇x · f(v) = 1 2 (v − u), ∂tv +∇x · f(u) = 1 2 (u− v) serves as a refined description of systems of hyperbolic conservation laws ∂tφ +∇x · f(φ) = 0, φ(x, 0) = φ0(x). The solution of conservation laws is precisely captured when two components take the same initial value as φ0, or approached by two components exponentially fast when 2 ↓ 0 if t...

In using acoustic emissions (AE) for mechanical diagnostics, one major problem is the differentiation of events due to crack growth in a component from noise of various origins. This work presents two algorithms for automatic clustering and separation of AE events based on multiple features extracted from experimental data. The first algorithm consists of two steps. In the first step, the noise...