Il Nuovo Cimento D (Nuovo Cimento Soc Ital Fisica)

Publisher: Società italiana di fisica, Società Italiana di Fisica

Journal description

Discontinued in 1998.

Current impact factor: 0.00

Impact Factor Rankings

2016 Impact Factor Available summer 2017
2000 Impact Factor 0.393
1999 Impact Factor 0.368
1998 Impact Factor 0.418
1997 Impact Factor 0.462

Impact factor over time

Impact factor
Year

Additional details

5-year impact 0.00
Cited half-life 0.00
Immediacy index 0.00
Eigenfactor 0.00
Article influence 0.00
Website Nuovo Cimento della Società Italiana di Fisica - D: Condensed Matter, Atomic, Molecular and Chemical Physics, Biophysics website
Other titles Nuovo Cimento della Società italiana di fisica, [Sezione] D, Nuovo cimento della Società italiana di fisica., Condensed matter, atomic, molecular and chemical physics, biophysics, Condensed matter, atomic, molecular, and chemical physics, fluids, plasmas, biophysics
ISSN 0392-6737
OCLC 8724239
Material type Periodical, Internet resource
Document type Journal / Magazine / Newspaper, Internet Resource

Publisher details

Società Italiana di Fisica

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • On author's personal website and institutional repository
    • Publisher's version/PDF cannot be used
    • Published source must be acknowledged
    • Must link to publisher version
    • Set statement to accompany link, "The original publication is available at http://www.sif.ir/SIF/en/portal/journals"
    • Applies to Il Nouvo Cimento B, Il Nouvo Cimento C, La Rivista del Nouvo Cimento, Vareena Proceedings and Conference Proceedings
  • Classification
    green

Publications in this journal

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    ABSTRACT: Using the Gaussian Ansatz for the monomer-monomer correlation functions we derive a set of the self-consistent equations for determination of the conformational state in the bead-and-spring copolymer model. The latter is based on the Edwards type effective free energy functional with arbitrary two-body interaction matrix. The rate of conformational changes in kinetics may be expressed via the instantaneous gradients of the variational free energy functional in the space of the averaged dynamical variables. We study the equilibrium and kinetics for some periodic and random aperiodic amphiphilic sequences in infinitely diluted solution. Typical equilibrium phase diagrams are elucidated and the conformational structure of different states is discussed. The kinetics of compaction of an amphiphilic copolymer to the globular state proceeds through formation of locally frustrated non-equilibrium structures. This leads to a rather complicated multistep kinetic process. We observe that even a small modification in the primary sequence of a copolymer may significantly change its kinetic folding properties.
    Preview · Article · May 2001 · Il Nuovo Cimento D
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    ABSTRACT: We find that loosely bound ordered clusters form in colloidal monolayers trapped at the water/ah- interface. This observation appears to demand the existence of an attractive component of the colloidal interaction which is absent from accepted theory. The range of this attraction must be quite long, as inter-particle separations in such meso-structures may be of the order of 8 μm. Possible origins of the novel attraction are discussed.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: A functional method is introduced which allows to derive exact solutions for a wide class of Volterra integro-differential equations in terms of Bessel-Clifford functions of half-integer order. These equations are applied to the description of chemical reactions and to the modelling of protein dynamics in non-Markovian cases, thus generalizing the usual Kramers approach in an easily computable way.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: We present experimental depolarized light scattering (DLS) results performed in propylene glycol (PG) and its oligomers polypropylene glycol (PPG) at different molecular weight 425, 725 and 4000, confined in 25 A pores of a sol-gel silica glass. The goal is to study the influence of the confinement on the molecular mobility of hydrogen-bonded liquids with identical chemical composition but different steric hindrance. Furthermore, we also studied the behaviour of this kind of intermolecular interaction thanks to the opportunity to control the number of active silanol group (Si-OH) and non-active (Si-OCH3) groups on the porous inner surfaces. In particular the removing of the OH groups in the inner surface represents an important tool to elucidate its role on the confined polymer dynamics. Comparing the obtained results performed on the hydrogen-bonded liquids in the active and non-active surfaces, the main role played by the original Si-OH surface on the studied dynamics is showed. Furthermore the reorientational dynamics in confined samples exhibit a noticeable slowing down compared with the corrispective in the bulk samples.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: We present an interpretation of the characteristic phase properties of microemulsions based on a distinct process of phase separation that has come to a standstill due to the action of the amphiphiles on the driving force of the process. In our kinetic equation this force relates to the generalized Laplace equation that contains spontaneous curvature and bending rigidity terms, and, according to it, the final stationary states attained are phases structured into water-rich and oil-rich domains. In relation to oui' model we discuss the change in geometry of the domains upon variation of spontaneous curvature and observe that the water-oil interfacial tension and the mean domain size exhibit their characteristic minimum and maximum, respectively. The kinetic equation is derived from the standard Landau-Ginzburg formalism using a free-energy density functional with square-gradient and square-Laplacian terms.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: The aggregation of porphyrins is a well-known behavior of this class of compounds. Aggregated porphyrins play a key role in many systems related to medicine and biology, e.g., the bacteriochlorophyll dimer, known as the "special pair", is the main electron donor in the bacterial reaction center. The large surface and planarity of the porphyrin chromophore favor strong van der Waals stacking interactions which lead to very large aggregates. Recently, we have studied the aggregation of a synthetic water soluble porphyrin (irans-H2Pagg), which on salt addition gives mesoscopic aggregates having a fractal structure mainly driven by a diffusion limited kinetic (DLA). Here we are reporting a study of such aggregation property on varying the salt concentration, obtaining evidences that different dynamics of aggregation exist in different ionic strength regimes.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: We study a continuum model for phase-separation in binary polymer blends based on the Cahn-Hilliard equation with the Flory-Huggins-De Gennes freeenergy functional and a concentration-dependent mobility. The model is solved analytically, by means of the self-consistent large-n limit approach, and numerically for values of the parameters corresponding to the weak and strong segregation limits, for both critical and off-critical blends. For deep quenches we identify a complex structure of intermediate regimes and crossovers and the existence of a time domain characterized by the pinning of the phase-ordering process. The duration of this stop is analytically computed and diverges differently when the chains length is increased or the temperature is lowered. This result allows the interpretation of recent experiments which show pinning in off-critical polymeric mixtures suggesting that the continuum model contains sufficient physical ingredients to explain the experimental evidence.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: In this paper we present an application of neutron Compton scattering to biological samples. This technique is capable of measuring the proton momentum distribution n(p), and other quantities related to the proton/deuteron potential well. The sample investigated consisted of fully HjO-exchanged, highly ordered DNA fibers at different temperatures. We report preliminary results about the widths of the Gaussian and Lorentzian components of the extracted proton momentum distribution.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: Morphology and phase separation kinetics of binary polymer mixtures with one-component undergoing chemical reactions were investigated by means of phase-contrast optical microscopy and digital image analysis. Two types of chemical reactions were performed on these blends: cross-linking using photodimerization of anthracene and reversible photoisomerization of stilbene. Both anthracene and stilbene were chemically attached to one polymer component and the reactions were initiated by irradiation with ultraviolet light in the one-phase region of the blends. It was found that both the reactions proceed inhomogeneously in the mixtures. As the reaction yield exceeds some extents, the polymer mixtures are destabilized and undergo phase separation. For both cases, the phase separation follows a power law of irradiation time and is eventually frozen by the reactions. These experimental results are discussed in conjunction with the mode-selection process driven by the cross-linking reactions as well as the reversible photoisomerization.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: A ferrosmectic is a lyotropic lamellar phase in which colloidal magnetic particles are incorporated between the surfactant membranes. These phases possess a strong anisotropy of magnetic susceptibility and undergo spectacular orientation transitions, through toroidal defect formation, when submitted to weak external magnetic field. In analogy with models of instabilities under external field in thermotropic smectics, we propose a description of the observed phenomena in terms of a phase transition. The critical field corresponding to the transition is calculated and compared to our experimental results. The model takes into account the binary nature of the system making possible the occurrence of a first-order type transition and includes a description of the elastic and magnetic energies involved in the distortion. The kinetic of the orientation transition qualitatively accounts for the occurence of a coexistence regime.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: Blends of isotactic Polypropylene (iPP) and Oligo Cyclo Pentadiene (HOOP) were studied both from a structural (SAXS and SANS) and dynamical (Raman scattering) point of view. In the solid state these blends present a lamellar morphology, crystalline iPP layers alternating to amorphous iPP+HOCP layers. The blend phase diagram is characterized by the existence of a miscibility gap. SAXS and SANS techniques are applied to investigate the structural features of both in-gap and outof-gap blends. SAXS and SANS patterns were Fourier inverted in order to extract the self-correlation fuction of the electronic (scattering length) density, γ(x). γ(x)'s were analysed in terms of a pseudo two-phase model, in the case of out-of-gap blends. This model allows to derive structural parameters, such as crystalline, amorphous and total (long period) thicknesses. As far as the dynamical response is concerned, low-frequency depolarized light scattering measurements on iPP, Polyethylene (PE) and their blends with HOOP, at melting point, were performed. This experimental dynamical study has the goal to show the main role played by the effective vibrational density of states in comparison with the reorientational diffusion contribution, since relaxations and vibrations are the two main terms that contribute to low-frequency Raman spectra of glass formers. On the other hand, the existence of a boson peak, characteristic of glass-forming systems, whose center-frequency shifts towards higher values, increasing the percentage of HOCR indicates the disorder effect connected to the presence of this component in the polymeric blends, as also shown by the evolution of the dynamical correlation length, Rc. Furthermore in the very low frequency range a crossover (wco ~ 0.1 THz) from a spectral phonon-like contribution to a fracton-like is detected. This behaviour has been interpreted accordingly with the recent theories on the excess of spectral density in such a kind of systems.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: Configurational degrees of freedom available to the structure of most biopolymers in their native state further increase when the extent of their hydration, particularly of proteins and nucleic acids, is raised. These allow water and ice to coexist in the proteins below 273 K, and increase the distribution of energy barriers for their structural relaxation. Hence, their vitrification occurs over an extremely broad, almost indiscernible, temperature range, as the configurational contribution to the thermodynamic functions is lost gradually on their cooling. When annealed, a hydrated protein loses part of its enthalpy and entropy spontaneously, as certain of its H-bonded subunits and HjO molecules relax during the annealing period. The time and temperature dependence of the thermodynamics and kinetics of this process of structural relaxation is studied by calorimetry of a native protein, beef, and mathematically formulated. A detailed analysis shows that at each temperature during the cooling of a hydrated beef sample, the native state of protein, the H-bond equilibrium becomes frozen-in, and that the frozen-in equilibrium quotient increases on isothermal annealing, as the number of H-bonds increases isothermally. The configuration contribution and the H-bonding contribution to the enthalpy and entropy become inseparable in biopolymers, as they should be for simpler materials. Description of both phenomena in general terms underscores the premise that simple model systems are not necessarily required for understanding the native protein's behaviour.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: The double-focusing high-flux wiggler beamline dedicated to Small Angle and Wide Angle X-ray Scattering (SAXSAVAXS) at ELETTRA has recently gone into operation. It has been designed specifically for time-resolved (resolution ∼ 1 ms) structure investigations on gels, liquid crystals, (bio)polymers, amorphous materials, muscles and proteins in solution. The beamline is working at 3 fixed energies, namely 5.4, 8 and 16 keV, therefore the beamline is equally applicable to very thin (e.g., single muscle fibres) and optically thick (alloys or ceramics, having high Z) specimen. At the photon energy of 8 keV the SAXS-resolution ranges from 1 to about 140 nm in d-spacing, and the flux at the sample is 2 × 1012 photons/s corresponding to a flux density of 5 × 1011 ph/s (ELETTRA: 2 GeV and 250 mA). It is also possible to perform simultaneously wide-angle diffraction measurements in the d-spacing range of 0.12 to 0.94 nm (at 8 keV). Typical spot sizes are 5.4 × 1.8 mm2 at the sample and 1.2 × 0.6 mm2 in the focal spot. A multi-purpose sample stage allows to install a large variety of user-designed instrumentationorder to perform temperature scans and jumps, pressure scans and jumps, shear and flow jump relaxation experiments, grazing incidence SWAXS, micro-spot scanning SWAXS, as well as studies applying mechanical stresses or magnetic fields.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: We investigated phase-separating structures developed via spinodal decomposition (SD) for critical mixtures of polymers and simple liquids. The scaled structure factors for each system constructed at various times during SD are universal with time in the late stage SD process. Moreover, the universal scaled structure factors for the nearly symmetric polymer mixtures were found to be identical to those for the critical simple-liquid mixtures, revealing that the form of the evolving structures in two systems is statistically identical. In order to visualize this form, we investigated both experimentally and computationally three-dimensional real-space structures corresponding to the universal scaled structure factor. The results elucidated that the form is characterized by the sponge-like structure having a saddle-like (hyperbolic) interface with (K) < 0 and (H) = 0, where (K) and (H) are the area-averaged Gaussian and the mean curvatures at a given time t in the late stage SD.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: The structure of fibrin gels grown at room temperature from fibrinogen solutions at sevei'al fibrinogen concentrations was investigated by means of elastic light scattering. By combining Classical Light Scattering (CLS) and Low-Angle Elastic Light Scattering (LAELS) an overall wavevector range of more than two decades was spanned, from 7.8 × 102 to 3.3 × 05 cm-1. The scattered intensity distribution I(q) of all the gels was characterized by three different regimes. For q = q1 ∼ 2.5 × 103 cm-1, I(q) exhibits a maximum which indicates the presence of a long-range order in the gel structure, with an average mesh size ζ1 = 2ζ/q1 ∼ 25μm. For q1 < q2(q2 ∼ 1-3 × 105 cm-1), the scattered intensity distribution decays with a power law characterized by the mass fractal exponent Dm = 1.20 ±0.05, which is typical of branched linear polymers. At larger wavevectors, for q > q2, there is a crossover to a scattering from surface fractals, where I(q) decays with a power law characterized by an exponent of ~ -4. The length scale ζ2 = 1/q2 ∼ 80 nm is an estimate of the average diameters of the gel fibers. All our results, including the kinetics of gel formation, can be described in terms of a simple model.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: DNA can form complexes with zwitterionic lipids in the presence of divalent cations. We investigated the complex formation between DNA and dioleoylphosphatidylcholine or soybean lecithin in a two-phase system, watercyclohexane. It was found that calcium induced transfer of DNA into the organic phase. The partitioning of DNA between water and organic phases was studied as a function of calcium, DNA and lipid concentrations.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: We review some recent results on the dynamics of molecules in deep supercooled states, extracted from the analysis of a series of long molecular dynamics simulations. The intermolecolar potential has been chosen for its ability of mimicking the interactions among water molecules in liquid state. We show that mode-coupling theory offers a reference frame for the understanding of the dynamics in molecular liquids above a dynamical critical temperature.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D
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    ABSTRACT: Inelastic X-rays scattering experiments can now be performed with MeV energy resolution at the Europeans Synchrotron Radiation Facility in Grenoble. This allows to measure the phonon spectrum in crystals and, more importantly, opens the possibility to measure the high-frequency dynamics in liquids and disordered systems. In disordered materials, in fact, neutron scattering cannot be applied because of the accessible kinematics region. An overview on the technique and its capabilities is reported here. Inelastic X-ray scattering has been used to study the high-frequency collective dynamics in liquid water, and we discuss results on the long-standing issue of the fast sound.
    No preview · Article · Jan 1999 · Il Nuovo Cimento D