A New Criteria Decision Applied on the Primary Synchronization in the DS-WCDMA Interface of the UMTS System

In DS-WCDMA mobile systems such the UMTS, asynchronous cell site operation,assigning different long spreading code to each cell, yields the advantageof flexible system deployment. We can design an indoor system basedon an outdoor one. However, in general, much longer search time isrequired in asynchronous operation than in synchronous. This paperproposes three techniques to take decisions about synchronizationbased on observation of correlated signals. Classical decision criterialike maximum and threshold criterion are presented. A new decisioncriteria that we call Threshold&Max combined decision criteriais analyzed. The results of this new introduced technique is comparedwith the classical ones.     

Diluent effects on carbonate mobility in bisphenol-A polycarbonate in the solid state

The effect of miscible low molecular weight additives on the mobility of the carbonate group in bisphenol-A polycarbonate (BPAPC) has been studied using n.m.r. and dielectric relaxation experiments in the solid state. Proton-enhanced dipolar-decoupled carbon-13 n.m.r. spectra of BPAPC, isotopically enriched at the carbonate position, are obtained without magic-angle sample spinning. The resolved chemical shift anisotropy allows study of nuclear spin relaxation for the carbonate groups in the polymer that have different orientations relative to the static magnetic field in the laboratory frame. The spin-lattice relaxation time in the rotating frame (T_1?) is measured at a motional-probe frequency of 50 kHz for the undiluted polymer and for BPAPC-diluent blends containing either dibutylphthalate or dinitrobiphenyl. The T_1? exhibits some dependence on orientation in all systems studied. In the blend containing dibutylphthalate (DBP), T_1? is decreased by a factor of two for all orientations of the carbonate group. This implies that DBP substantially increases the spectral density of 50 kHz motions in the carbonate region of the polymer at ambient temperature. In contrast, dinitrobiphenyl does not significantly alter the Fourier component of thermal fluctuations at 50 kHz. Dielectric relaxation measurements at 10 kHz reveal that the primary (T_g) and secondary (β) motional processes in BPAPC are affected by low molecular weight additives. An intermediate relaxation process appears in the temperature interval between the glass transition temperature (T_g) and the sub-T_g β-relaxation (T_β) in the polymer-diluent blends. The n.m.r. spin-lattice relaxation rate in the rotating frame, T^?1_1?, correlates well with the relative magnitude of the dielectric dissipation factor (tan δ_ε) between T_g and T_β.     

Multifunctional TiO2 coatings for Cultural Heritage

Environmental pollution arising from industrial implants and urban factors is constantly increasing, causing aesthetical and durability concerns to urban structures exposed to the atmosphere.     

The behaviour of consolidated Neapolitan yellow Tuff against salt weathering

Bulletin of Engineering Geology and the Environment - Salt crystallization is a strong weathering agent in porous building materials. The crystallization pressure exerted by salt crystals, growing...     

Effect of water‐absorbing nanospheres on antistatic property of isotactic polypropylene fibers

In this article, novel antistatic isotactic polypropylene (iPP) fibers were prepared through adding ternary polymer water‐absorbing nanospheres (TPWANs) into iPP melt in melt spinning process. The TPWANs were synthesized through emulsion copolymerization of styrene (St), butyl acrylate (BA), and sodium allylsulfonate (SAS). The characterization results of Fourier transform infrared spectrometer (FT‐IR) and ¹H nuclear magnetic resonance (¹H NMR) confirmed the ternary components in this copolymer. Transmission electron microscopy (TEM) images indicated the nanospherical shape of TPWANs with the characteristics of 80–90 nm size range of diameter and good dispersion in iPP fibers. The volume resistance of iPP fibers decreased by three orders from 10¹² to 10⁹ Ω cm when the 6 wt % TPWANs was added into iPP fibers, indicating that the blend fibers have good antistatic property. Most importantly, the nanospherical structure of TPWANs imparts both the compatibility and antistatic property into the blend iPP fibers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40568.     

Nonalcoholic Fatty Liver: A Possible New Target for Type 2 Diabetes Prevention and Treatment

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder worldwide. Several lines of evidence have indicated a pathogenic role of insulin resistance, and a strong association with type 2 diabetes (T2MD) and metabolic syndrome. Importantly, NAFLD appears to enhance the risk for T2MD, as well as worsen glycemic control and cardiovascular disease in diabetic patients. In turn, T2MD may promote NAFLD progression. The opportunity to take into account NAFLD in T2MD prevention and care has stimulated several clinical studies in which antidiabetic drugs, such as metformin, thiazolidinediones, GLP-1 analogues and DPP-4 inhibitors have been evaluated in NAFLD patients. In this review, we provide an overview of preclinical and clinical evidences on the possible efficacy of antidiabetic drugs in NAFLD treatment. Overall, available data suggest that metformin has beneficial effects on body weight reduction and metabolic parameters, with uncertain effects on liver histology, while pioglitazone may improve liver histology. Few data, mostly preclinical, are available on DPP4 inhibitors and GLP-1 analogues. The heterogeneity of these studies and the small number of patients do not allow for firm conclusions about treatment guidelines, and further randomized, controlled studies are needed.     

Thermophysical property modifications in functional polymers via lanthanide trichloride hydrates

Fourteen water‐soluble trivalent metal chlorides from lanthanum to lutetium in the 1st‐row of the f‐block form complexes with poly(vinylamine) and increase the glass transition temperature from 57°C to well above 100°C at very low molar concentrations of the lanthanide. The large ionic radii of these hard‐acid cations allow several hard‐base amino sidegroups in the polymer to occupy sites in the first shell coordination sphere via ion‐dipole (i.e., electrostatic) interactions, which leads to microclustering of the ligands about a single metal center. The enhancement in the glass transition temperature is explained in terms of multi‐functional coordination crosslinklng. f‐Block salts induce larger increases in T_g, relative to transition metal‐complexes from the d‐block, however CoCl₂(H₂O)₆ performs comparably to some of the more efficient lanthanides. Blends of poly(vinylamine) and trimethoxysilyl‐propylpoly(ethylene imine)hydrochloride form complexes with europium(III) and exhibit synergistic single T_g response. Since lanthanides form very stable complexes with chelating (i.e., bidentate) oxygen ligands, it is possible to increase the elastic modulus of commercially important copolymers of ethylene and methacrylic acid via Eu³⁺ complexation with the carboxylate anion. This claim is verified by infrared spectroscopy. Temperature and pH‐sensitive applications for drug delivery and removal of contaminants from wastewater streams should increase the utility of these lanthanide complexes.     

Space–Time Coding for Multiuser Ultra-Wideband Communications

In this paper, we present the construction of full rate, fully diverse, and totally real space-time (ST) codes for ultra-wideband (UWB) transmissions. In particular, we construct two families of codes adapted to real carrierless UWB communications that employ pulse position modulation, pulse amplitude modulation, or a combination of the two. The first family encodes adjacent symbols and is constructed from totally real cyclic division algebras. The second family encodes the pulses used to convey one information symbol, and permits achieving high performance levels with reduced complexity. The first family of codes achieves only a fraction of the coding gain of the second one. Moreover, these coding gains are independent from the size of the transmitted constellation. For time-hopping multiple-access channels, the amplitude spreading code associated with the second family of codes is taken to be user-specific. In this case, a simple design criterion is proposed, and spreading matrices constructed according to this criterion permit reducing the level of multiple-access interference (MAI). Simulations performed over realistic indoor UWB channels verify the theoretical claims and show high performance levels and better immunity against MAI     

Distributed Databases for the development of Mechanisms Topology

In this paper different types of data structures for database modeling are reviewed in order to suggest the one which most suits the needs of a database management system dedicated to the study of the mechanical systems. Topology is proposed as the classification criterion, this inspiration being due to the separation of the concepts of structure and function, as proposed for the first time by Freudenstein and Maki [Environ. Planning B 6 (1979) 375–391]. An example of a local database is herein presented and, finally, the adopted codes are briefly commented upon which, on the base of the evaluation of the power of the adjacency matrices, identify the kinematic chains (KCs) and mechanisms.     

A brief note on the concept of planarity for kinematic chains

In this note the concept of planarity is briefly reviewed with the aim of suggesting a unified interpretation of this word as an attribute of the concept of kinematic chain. The lack of a correct and unambiguous meaning of the concept of planar kinematic chain may cause serious misunderstandings nowadays, as in the reported example.