An objective of the study is to get new biogeographic information on the modern polycystine radiolarians from the high-latitude North Atlantic. The quantitative radiolarian dataset was compiled from publications and own micropaleontological counts from samples of the bottom surface sediments of the North Atlantic north of 40N and Nordic Seas. Standard statistical treatment of micropaleontologic...

We propose and analyze an efficient way to enhance four-wave mixing (FWM) signals in a four-subband semiconductor quantum well via Fano-type interference. By using Schrödinger-Maxwell formalism, we derive explicitly analytical expressions for the input probe pulse and the generated FWM field in linear regime under the steady-state condition. With the aid of interference between two excited subb...

Article history: Accurate assessment of ph Received 4 February 2008 Received in revised form 16 April 2008 Accepted 19 April 2008

We consider the resonant effects of chaotic fluctuations on a strongly damped particle in a bistable potential driven by weak sinusoidal perturbation. We derive analytical expressions of chaos-induced transition rate between the neighboring potential wells based on the inhomogeneous Smoluchowski equation. Our first-order analysis reveals that the transition rate has the form of the Kramers esca...

Domestic wells in North America and elsewhere are typically constructed at relatively shallow depths and with the sand or gravel pack extending far above the intake screen of the well (shallow well seal). The source areas of these domestic wells and the effect of an extended gravel pack on the source area are typically unknown, and few resources exist for estimating these. In this article, we u...

Dropshafts are commonly used in sewers and stormwater channels as energy dissipator systems. Since recent effort has been devoted to characterize dropshaft hydraulics and air-water flow properties, and the present paper develops an analysis of the bubble clustering process using new experimental data collected in a large-size facility. The results highlight some significant patterns in clusters...

drinking water quality can be deteriorated by microbial and toxic chemicals during transport, storage and handling before using by the consumer. this study was conducted to evaluate the microbial and physicochemical quality of drinking water from bottled water coolers.a total of 64 water samples, over a 5-month period in 2012-2013, were collected from free standing bottled water coolers and wat...