The pleistocene clastic deposits of the latium coast—Italy

Close to the present Latium coast, at Rio Torto, in the area between Pomezia and Ardea, about 35 km to the South of Rome, there are vast sandy deposits of continental and marine origin that may be associated with ancient coast lines. The extent and thickness of these deposits vary widely and are used as sources for extracting aggregate materials that are successfully used in preparing cement mortars. Field surveys and laboratory tests have helped identify these products as belonging to a paleogeographic environment and to define both their volume and their geographic location. The results obtained have allowed characterization of the sands from a technical point of view and to define their fields of utilization keeping account of their location and their mining availability.     

Accurate polarization measurements with a dual photoelastic modulator

Measurements of the polarization effects in multimirror experiments by using a dual photoelastic modulator are described. The effect of single and multiple mirrors in polarization measurements in two and three dimensions is discussed, and experimental results show how symmetrical placement of mirrors in three-dimensional geometry can eliminate changes in the polarization. Calibration procedures for a dual photoelastic modulator and potential error sources such as misalignment of analyzer, signal dc offset, and neglect of aperture size are presented. Mirror-surface evolution and how it can disturb the polarization measurement are also addressed.     

Microfluidic gradient-generating device for pharmacological profiling

We describe an on-chip microfluidic gradient-generating device that generates concentration gradients spanning nearly 5 orders of magnitude starting from a single concentration. The exiting stream of drugs held at different concentrations remains laminar in a recording chamber and can be presented as 24 discrete solutions to a cell-based sensor. The high-performance characteristics of the device are demonstrated by pharmacological screening of voltage-gated K+ channels (hERG) and ligand-gated GABA(A) receptors using scanning-probe patch-clamp measurements. Multiple data point dose-response curves and IC50 and EC50 values were rapidly obtained, typically in less than 30 min, through its combined functionality of gradient generation and open-volume laminar flow. The device facilitates rapid pharmacological profiling of ion channel and GPCR effectors and enables the acquisition of large numbers of data points with minute sample consumption and handling.     

A novel method for determination of size resolved, submicrometer particle traffic emission factors

A novel approach to determine size-segregated particle number emission factors for traffic is presented. It was proven that using limited data sets (800-2000 samples) statistically significant emission factors from road traffic can be extracted. In this study data from four sites were used for calculating emission factors (rural and urban roadside, urban rooftop, and urban background). The measurements were performed using SMPS/DMPS (scanning or differential particle sizers) from TSI and commercial gas analyzers. Describing the particle concentration as a ratio to an exhaust trace gas, e.g. NOx, the dilution effect will be minimized. This ratio is easily compared among different studies. By knowledge of the emission factor of the chosen trace gas the emission ratio can be converted to an emission factor for particle numbers of defined particle sizes. For the presented method only one measurement site is needed, where the difference between high and low (background) traffic exposure is used. To define high and low traffic exposure, the best result was obtained using high ratio of [NO] to [NO2] and low [NOx], respectively. Emission ratios for 10-100-nm particles at two road sites, one high-speed 90-kmph rural case and one urban, slower, and more congested situation, were determined to (35 +/- 15) x 10(14) and (24 +/- 8) x 10(14) particles per mole NOx, respectively.     

Influence of OH scavenger on the water effect on secondary organic aerosol formation from ozonolysis of limonene, Delta3-carene, and alpha-pinene

The effect of OH scavengers on how water vapor influences the formation of secondary organic aerosol (SOA) in ozonolysis of limonene, Delta3-carene, and alpha-pinene at low concentrations has been investigated by using a laminar flow reactor. Cyclohexane and 2-butanol (3-40 x 10(13) molecules cm(-3)) were used as scavengers and compared to experiments without any scavenger. The reactions were conducted at 298 K and at relative humidities between <10 and 80%. The yield of SOA decreased in the order "no scavenger" > 2-butanol > cyclohexane. The effect of water vapor was similar for 2-butanol and without a scavenger, with an increase in particle number and mass concentration with increasing relative humidity. The water effect for cyclohexane was more complex, depending on the terpene, scavenger concentration, and SOA concentration. The water effect seems to be influenced by the HO2/RO2 ratio. The results are discussed in relation to the currently suggested mechanism for alkene ozonolysis and to atmospheric importance. The results imply that the ozone-initiated oxidation of terpenes needs revision in order to fully account for the role of water in the chemical mechanism.     

Shape preserving design of vibrating structures using topology optimization

In several engineering components, the shape of some functional surfaces needs to be preserved in order to avoid losing performance or even its functionality when subjected to loads. This is particularly important when tight tolerances are required for operational conditions in some regions. If the deformation significantly affects product functionality, it is interesting to use a shape preserving design technique. This will often reduce deformation in a local region. To achieve that, we deal with topology optimization of elastic, continuum structures with Rayleigh damping, subjected to time-harmonic, design-independent external dynamic loading with prescribed excitation frequency, amplitude and spatial distribution. In topology optimization for vibrating structures, the obtained design should often have its resonance frequencies driven far away from the given excitation frequency in order to avoid resonance and to reduce vibration levels. In this work, we explore harmonic vibration problems with the excitation frequency lower than the first resonance frequency of the initial structure. Dynamic compliance minimization is used to improve dynamic response of the structure. An additional local dynamic compliance constraint is used to define the shape preserving problem, thus, reducing deformation in specific regions of a part named shape preserving region (SPR). A commercial FE code (ANSYS^?) is used to solve the finite element problem. The optimization Method of Moving Asymptotes (MMA) is used with the modified Solid Isotropic Material with Penalization (SIMP) material interpolation scheme. The effectiveness of this technique is presented using 2D plane structures. Coherent results were achieved using the proposed optimization formulation. It is possible to observe significant decrease on local deformation, at expense of little increase on global dynamic compliance.     

The variation of bedrock quality with increasing ductile deformation

Most of the rocks in Precambrian shield areas have experienced a complex structural and metamorphic evolution, processes which have a strong influence on the bedrock quality. This may vary both on a local and regional scale. The main object of this investigation was to study the variation of the rock mechanical properties at various stages of ductile deformation of an originally isotropic rock. Ten samples from five different localities northeast of Lake Vänern (south central Sweden) were tested, including studded tyre and LA tests, uniaxial compressive strength (UCS), ultrasonic velocity, electrical resistivity, Swedish impact value and Swedish flakiness index as well as petrographic and chemical analyses. This study highlights the importance of considering all possible variations in bedrock before classification, and of undertaking regional investigations.     

Mobilisation of heavy metals by deicing salts in a roadside environment

The seasonal variations of some selected heavy metals (Cd, Cu, Pb and Zn) and principal anions in soil solutions were monitored as a function of distance from the road at two field sites in Sweden. During the winter, the conductivity, concentrations of dissolved sodium and chloride increased dramatically due to the application of deicing agents (i.e. NaCl). Due to ion exchange, the pH decreased one unit in the soil solutions, whereas the concentrations of total organic carbon decreased due to coagulation and/or sorption to stationary solids. The heavy metal concentrations increased during the winter, but through different mechanisms. Cadmium concentrations in the aqueous phase increased as a response to ion exchange, possibly also enhanced by the formation of chloride complexes. Similarly, the concentrations of zinc increased, due to ion exchange, with calcium and protons. The mechanisms of mobilisation for copper and lead were not that clear probably due to association with coagulated or sorbed organic matter in combination with colloid dispersion.     

Acute effects of qigong exercise on mood and anxiety.

Psychosocial stress may lead to increased rates of anxiety and depression. Aerobic exercise and mind-body therapies are frequently described as having positive effects on psychological well-being by enhancing mood and reducing anxiety. Few studies, however, have investigated the acute psychological effects of qigong exercise. Fifty-nine regular qigong exercisers (mean age 50.8 years) were randomized to a Qigong or Control group. Pre- and postmeasurements were then compared. POMS-Depression, Anger, and Fatigue, and STAI-State Anxiety scores decreased significantly in the Qigong group but not in the Control group. Results thereby suggest that qigong exercise can produce desirable psychological effects, and Qigong exercise may therefore be included among other activities performed to boost resistance to daily stressors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)