Characteristics of particle-associated PAHs in a first flush of a highway runoff.

Runoff monitoring of six rainfall events was carried out in a highway, Winterthur, Switzerland focusing on first flush (runoff volume up to 2.88 mm). Six runoff events were used to investigate the characteristics of particle-associated PAHs in first flush. The fine fraction (< 45 microm) had a relatively higher contribution than the coarse fraction. A significant contribution of the coarse fraction was observed at some periods when the runoff flow rapidly increased. Fluctuation of PAH content during a runoff event was significant in the coarse fraction and, in contrast, the PAH content in the fine fraction was less fluctuating. The weighted average PAH content in each event ranged from 17 to 62 microg/g in total SS, from 23 to 54 microg/g in the fine fraction and from 16 to 84 microg/g in the coarse fraction. The loading of particle-associated PAHs from the first flush of highway runoff ranged from 0.06 to 0.22 g/ha in a total of 12 PAH species.     

Steady-state longitudinal vibrations of sectional,physically nonlinear plates

The artile deals with steady-state longitudinal vibrations of plates consisting of curvilinear rings placed one inside the other without interference, under the effect of a harmonic distorting load acting along the outer periphery. The rings are made from different isotropic materials that are physically nonlinear. The problem is solved by the method of successive approximations. In each approximation the sought functions are represented in the form of expansions with respect to a small parameter. Numerical investigations were carried out for plates consiting of two concentrically arranged circular rings.Translated from Problemy Prochnosti, No. 3, pp. 24–27, March, 1991.     

Oil Spill Cleanup from Sea Water by Sorbent Materials

Three sorbents were compared in order to determine their potential for oil spill cleanup. Polypropylene nonwoven web, rice hull, and bagasse with two different particle sizes were evaluated in terms of oil sorption capacities and oil recovery efficiencies. Polypropylene can sorb almost 7 to 9 times its weight from different oils. Bagasse, 18 to 45 mesh size, follows polypropylene as the second sorbent in oil spill cleanup. Bagasse, 14 to 18 mesh size, and rice hull have comparable oil sorption capacities, which are lower than those of the two former sorbents. It was found that oil viscosity plays an important role in oil sorption by sorbents. All adsorbents used in this work could remove the oil from the surface of the water preferentially.     

Smart help for operator performance

Our emphasis in this paper has been on the knowledge-based and cognitive issues pertinent for improved interactions between workers and manufacturing computer systems. We believe that these techniques are as necessary and applicable to manufacturing as to any other vocation, especially as the difference in collar color of shop people becomes less noticeable in their increasing role as knowledge workers.     

Theoretical and experimental study of mass sensitivity of PSAW-APMson ZX-LiNbO3

Acoustic plate mode (APM) devices have recently been used as sensing elements, both for the physical measurement of fluid properties and in biosensor applications. One of the primary interaction mechanisms in these devices is mass loading caused by the added mass bound to the layered crystal surface. However, the material properties of these thin composite layers are not well characterized or known as is required in order to accurately predict the sensor response. In the present work, perturbation theory is used to derive expressions for the sensitivity of the APM sensors to mass loading and viscoelastic stiffening. Mass sensitivity experiment was conducted on ZX-LiNbO₃ in a liquid environment to accurately reflect the sensitivity of an actual biosensor and the results are compared to theory. The measured data show a f² dependence for the mass sensitivity for APMs on ZX-LiNbO₃ in the measured frequency range, which indicates a SAW-like behavior. This behavior is due to the fact that the acoustic plate modes on ZX-LiNBO₃ are pseudo-SAW (PSAW) derived, and the acoustic energy is confined to the sensing surface. As a result, the APMs on ZX-LiNbO₃ are referred to as PSAW-APMs. Discussions are given in terms of the added mass which occurs in typical biosensor applications     

Economical technology for cryoproduct storage and delivery

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 11, pp. 22–23, November, 1992.     

Y Zeolite as a component of catalysts for hydrotreating petroleum fractions

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 7–12, March, 1991.