Genetic algorithm-based MMSE receiver for MC-CDMA systems transmitting over time-varying mobile channels

A novel multi-user detector, based on a genetic algorithm-assisted per-carrier MMSE criterion, is proposed for MC-CDMA systems transmitting over time-varying multipath fading channels. The analysed multi-user detector outperforms state-of-the-art adaptive receivers based on deterministic gradient algorithms, particularly for an increasing number of users     

Immediate and Time-Dependent Compression of Tire Derived Aggregate

This paper examines immediate and time-dependent compression of tire derived aggregate (TDA) and TDA-soil composites. To accommodate large particle sizes, modified experimental devices were developed and used to test tire chips and tire shreds. Immediate compression of TDA, which results almost entirely from the reduction of pore volume, increases with TDA content and tire particle size. The secant constrained modulus (Msec) of TDA defined over the stress range of 0–50?kPa varied from a low of 255?kPa (100% tire shreds) to a high of 1,320?kPa (50% tire chips). A characteristic relationship between strain and time exists for TDA and TDA composites under one-dimensional confined compression. Time-dependent deformation is well described by the modified secondary compression index (Cαε), which ranged from 0.0010 (50% tire chips) to 0.0074 (100% tire chips). Time-dependent deformation was inversely proportional to sand content, with the most significant changes resulting from the addition of 15% sand. Both applied stress and tire particle size appear to have a negligible effect on time-dependent compression of TDA. Based on the findings of this study it is recommended that practitioners assess time-dependent settlement when designing a TDA structure and if necessary incorporate design features to accommodate these settlements.     

Infrared Comb Spectroscopy of Buffer-Gas-Cooled Molecules: Toward Absolute Frequency Metrology of Cold Acetylene

We review the recent developments in precision ro-vibrational spectroscopy of buffer-gas-cooled neutral molecules, obtained using infrared frequency combs either as direct probe sources or as ultra-accurate optical rulers. In particular, we show how coherent broadband spectroscopy of complex molecules especially benefits from drastic simplification of the spectra brought about by cooling of internal temperatures. Moreover, cooling the translational motion allows longer light-molecule interaction times and hence reduced transit-time broadening effects, crucial for high-precision spectroscopy on simple molecules. In this respect, we report on the progress of absolute frequency metrology experiments with buffer-gas-cooled molecules, focusing on the advanced technologies that led to record measurements with acetylene. Finally, we briefly discuss the prospects for further improving the ultimate accuracy of the spectroscopic frequency measurement.     

Long-Term Shaping of Corticostriatal Synaptic Activity by Acute Fasting

Food restriction is a robust nongenic, nonsurgical and nonpharmacologic intervention known to improve health and extend lifespan in various species. Food is considered the most essential and frequently consumed natural reward, and current observations have demonstrated homeostatic responses and neuroadaptations to sustained intermittent or chronic deprivation. Results obtained to date indicate that food deprivation affects glutamatergic synapses, favoring the insertion of GluA2-lacking α-Ammino-3-idrossi-5-Metil-4-idrossazol-Propionic Acid receptors (AMPARs) in postsynaptic membranes. Despite an increasing number of studies pointing towards specific changes in response to dietary restrictions in brain regions, such as the nucleus accumbens and hippocampus, none have investigated the long-term effects of such practice in the dorsal striatum. This basal ganglia nucleus is involved in habit formation and in eating behavior, especially that based on dopaminergic control of motivation for food in both humans and animals. Here, we explored whether we could retrieve long-term signs of changes in AMPARs subunit composition in dorsal striatal neurons of mice acutely deprived for 12 hours/day for two consecutive days by analyzing glutamatergic neurotransmission and the principal forms of dopamine and glutamate-dependent synaptic plasticity. Overall, our data show that a moderate food deprivation in experimental animals is a salient event mirrored by a series of neuroadaptations and suggest that dietary restriction may be determinant in shaping striatal synaptic plasticity in the physiological state.     

Photography and Communication Media in the Nineteenth Century

The increasing interest in media history within the academic world has not yet resulted in an intensive examination of the relationship between photography and communications media. This article seeks to begin to address this lacuna by examining photography's insertion into the so-called revolution of communication in middle-nineteenth-century America. The first section of the present study links photography to the introduction of telegraphy, the development of the railway and the expansion of the postal system. The second section examines aspects of the reception of photography in nineteenth-century America and argues this is related to improvements in communication and transportation technologies. The conclusion calls for a broader consideration of the links between the history of photography and the history of media.     

Mercury adsorption on granular activated carbon in aqueous solutions containing nitrates and chlorides

Adsorption is an effective process to remove mercury from polluted waters. In spite of the great number of experiments on this subject, the assessment of the optimal working conditions for industrial processes is suffering the lack of reliable models to describe the main adsorption mechanisms. This paper presents a critical analysis of mercury adsorption on an activated carbon, based on the use of chemical speciation analysis to find out correlations between mercury adsorption and concentration of dissolved species. To support this analysis, a comprehensive experimental study on mercury adsorption at different mercury concentrations, temperatures and pH was carried out in model aqueous solutions. This study pointed out that mercury capture occurs mainly through adsorption of cationic species, the adsorption of anions being significant only for basic pH. Furthermore, it was shown that HgOH(+) and Hg(2+) are captured to a higher extent than HgCl(+), but their adsorption is more sensitive to solution pH. Tests on the effect of temperature in a range from 10 to 55 °C showed a peculiar non-monotonic trend for mercury solution containing chlorides. The chemical speciation and the assumption of adsorption exothermicity allow describing this experimental finding without considering the occurrence of different adsorption mechanisms at different temperature.     

Cadmium adsorption by coal combustion ashes-based sorbents--relationship between sorbent properties and adsorption capacity

A very interesting possibility of coal combustion ashes reutilization is their use as adsorbent materials, that can also take advantage from proper beneficiation techniques. In this work, adsorption of cadmium from aqueous solutions was taken into consideration, with the emphasis on the intertwining among waste properties, beneficiation treatments, properties of the beneficiated materials and adsorption capacity. The characterization of three solid materials used as cadmium sorbents (as-received ash, ash sieved through a 25 μm-size sieve and demineralized ash) was carried out by chemical analysis, infrared spectroscopy, laser granulometry and mercury porosimetry. Cadmium adsorption thermodynamic and kinetic tests were conducted at room temperature, and test solutions were analyzed by atomic absorption spectrophotometry. Maximum specific adsorption capacities resulted in the range 0.5-4.3 mg g(-1). Different existing models were critically considered to find out an interpretation of the controlling mechanism for adsorption kinetics. In particular, it was observed that for lower surface coverage the adsorption rate is governed by a linear driving force while, once surface coverage becomes significant, mechanisms such as the intraparticle micropore diffusion may come into play. Moreover, it was shown that both external fluid-to-particle mass transfer and macropore diffusion hardly affect the adsorption process, which was instead regulated by intraparticle micropore diffusion: characteristic times for this process ranged from 4.1 to 6.1d, and were fully consistent with the experimentally observed equilibrium times. Results were discussed in terms of the relationship among properties of beneficiated materials and cadmium adsorption capacity. Results shed light on interesting correlations among solid properties, cadmium capture rate and maximum cadmium uptake.     

Validation of a method for composition measurement of a non-standard liquid fuel for Emission Factor evaluation

In this paper the theoretical and experimental aspects are described concerning the validation of a method for the measurement of the percentage composition of a generic liquid fuel, even though specific reference materials for instrumentation calibration are unavailable. This new method could be used for the evaluation of the Emission Factor (EF) of an unknown fuel for emission trading purposes, according to the requirements of both the juridical and technical standards. The validation of the procedure is based on the comparison of different techniques for the measurement of Gross Calorific Value (GCV), Net Calorific Value (NCV) which are quantities useful in EF evaluation; this new combination of actions established a complete and validated methodology for EF evaluation. The experimental results and uncertainty analysis show that this method is suitable for the estimation of the composition measurement and also that of GCV, NCV and EF also for non-standard liquid fuels; a comparable accuracy with respect to the methods for standard fuels has been estimated, making this method suitable for practical applications.     

Electronic nose to study postharvest dehydration of wine grapes

Montepulciano grapes were dehydrated at 10 and 20 °C, 45% RH and 1–1.5 m/s of air flow. Samplings were performed at 10%, 20%, 30%, and 40% of weight loss (wl). TSS (total solids content) increased up to 43° and 36° Brix at 20 and 10 °C, respectively, in 27 and 48 days. A straight regression line between M (kg water/kg dry matter) loss and days of dehydration with R² values, equal to 0.97, was found but an angular coefficient of −0.048 and −0.038, respectively at 20 and 10 °C indicated a different rate of weight loss. Volatiles compounds profile changed significantly with the temperature during the dehydration process. Anaerobic metabolites such as ethanol, acetaldehyde, and ethylacetate were much higher at 20 °C than at 10 °C and rose progressively, while at 10 °C, the significant rise was observed between 30% and 40% weight loss. Alcohols and esters prevailed at 20 °C while at 10 °C larger abundances of aldehydes and terpene alcohols are observed. PCA analysis of GC/MS confirmed the volatiles compounds separation between the samples held at 20 and 10 °C. A progressive evolution of the profile is observed for the samples held at 20 °C while those held at 10 °C show a change of volatiles compounds profile only at 40% wl. Loadings analysis show that aldehydes and terpenols are oriented towards the direction of 10 °C samples while alcohols and esters in that of 20 °C samples. The behaviours of GC/MS data were partially corroborated by the data of electronic nose. Electronic nose was able to follow the progressive change of aroma profile at 20 °C while at 10 °C grouped the responses obtained at 10%, 20%, 30% wl all together but at 40% wl, it discriminated the aroma response. This result opens a window on the potential use to monitor commercially the grape dehydration.