1,721,241 research outputs found
Nile Red lifetime reveals microplastic identity
No full textMicroplastic pollution is recognized as a worldwide environmental problem. The increasing daily use and release of plastics into the environment have led to the accumulation of fragmented microplastics, with potentially awful consequences for the environment, and animal and human health. The detection and identification of microplastics are of utmost importance, but available methods are still limited. In this work, a new approach is presented for the analysis of microplastics based on hydrophobic fluorescence staining with Nile Red, using spectrally resolved confocal fluorescence microscopy and fluorescence lifetime imaging microscopy (FLIM). Significant differences were observed in the emission spectra and fluorescence lifetimes of the analyzed microplastics. Nile Red fluorescence shows determinable behavior based on the polymer matrix and provides a fingerprint for the identification of fragments from different types of plastics. Lifetime imaging coupled with phasor analysis constitutes a fast, robust, and straightforward method for mapping and identifying different microplastics within the same sample in an aquatic environment
Channel Impairment Effects on TPRC for Multicode V-BLAST with CD-SIC
No full textIn third generation communication systems currently in standardization process, a number of multi-antenna schemes, derived from the well-known Bell Labs layered space-time (BLAST) approach, are being considered in order to improve performance in both communication reliability and system throughput. Among these schemes there is growing interest on schemes with feedback to aid the transmitter side (usually the Base Station) in adapting the transmission parameters, as modulation and coding rate and/or antenna/code power allocation, to the channel conditions. One of the proposed schemes is the Transmission Power Ratio Control (TPRC) for Multi-code Vertical-BLAST (with code domain serial interference cancellation, CD-SIC). The present work is motivated by observation that this scheme relies on negligibility of channel delay spread with respect to CDMA symbol length and ideal channel estimate both for data detection and feedback parameters estimation. Object of this paper is the qualitative and quantitative analysis of the effects of inter-symbol interference (ISI) and imperfect Channel State Information (CSI) on a receiving structure based on TPRC for CD-SIC. During the development of the present work, a generalized system model taking into account various channel impairments has been derived and reported
Note illustrative della Carta Geologica d’Italia alla scala 1:50.000 del Foglio 608 “Caccamo”
No full textTriangle zone and passive-roof duplexes in central-western Sicily? new insight from seismic interpretation
No full textJoint LMMSE equalizer for HSDPA in full-rate space time transmit diversity schemes
No full textThis contribution presents a joint linear minimum mean square error (LMMSE) equalizer for full-rate space-time transmit diversity multi-code schemes based on W-CDMA, featuring two and four transmit antennas. Specifically, high-rate, high load systems are targeted, in order to analyze the high speed downlink packet access (HSDPA) of 3GPP Release 6. We derive an equivalent transmission scheme to equalize the received sufficient statistic in a single stage. To reduce the effects of multipath and multiuser interference, and to provide spatial and frequency diversity at the receiver, an LMMSE equalizer is employed. Computer simulations confirm that the proposed schemes achieve robust performance over frequency-selective fading channels
[Considerations on platelet aggregation inhibition in patients treated with acetylsalicylic acid].
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