Supercritical Equilibrium Data of the Systems Carbon Dioxide—Linalool and Carbon Dioxide—Orange Essential Oil

In this paper experimental equilibrium data on the system supercritical CO2-orange essential oil and the system supercritical CO2-linalool are reported at 323.15 K and 343.15 K, for pressures in the ranges of 7.6-13.5 MPa. The behavior of the system supercritical CO2-orange essential oil was represented by means of thermodynamic model, based on Peng-Robinson equation of state. To this aim the orange essential oil was represented by a mixture of limonene, linalool and β-caryophyllene, selected to represent the classes of monoterpenes, oxygenated terpenes and sesquiterpenes respectively. The model uses only regression parameters calculated from binary sub-systems, CO2-limonene and CO2-β-caryophyllene (taken from literature) and CO2-linalool (calculated from the fitting of original data reported in the present work) thus being predictive with respect to the multicomponent mixture.

The effect of humidity on the CO_2/N_2 separation performance of copolymers based on hard polyimide segments and soft polyether chains:Experimental and modeling

In this work, we studied two copolymers formed by segments of a rubbery polyether（PPO or PEO） and of a glassy polyimide（BPDA-ODA or BKDA-ODA） suitable for gas separation and CO2 capture. Firstly, we assessed the absorption of water vapor in the materials, as a function of relative humidity（R.H.）, finding that the humidity uptake of the copolymers lies between that of the corresponding pure homopolymers values.Furthermore, we studied the effect of humidity on CO2 and N2 permeability, as well as on CO2/N2 selectivity, up to R.H. of 75%. The permeability decreases with increasing humidity, while the ideal selectivity remains approximately constant in the entire range of water activity investigated. The humidity-induced decrease of permeability in the copolymers is much smaller than the one observed in polyimides such as Matrimid? confirming the positive effect of the polyether phase on the membrane performance.Finally, we modeled the humidity-induced decrease of gas solubility, diffusivity and, consequently, permeability, using a suitable approach that considers the free volume theory for diffusion and LF model for solubility. Such model allows estimating the extent of competition that the gases undergo with water during sorption in the membranes, as a function of the relative humidity, as well as the expected reduction of free volume by means of water molecules occupation and consequent reduction of diffusivity.

On the Use of SPH for Mechanical Engineering Structural Analyses： An Elastic Linear Case

In this paper the use of Smoothed Particle Hydrodynamics method is presented in the Mechanical Engineering framework. In particular a two dimensional plain strain elastic linear problem is described and solved by two different approaches. Smoothed Particle Hydrodynamics is a meshless computational scheme able to perform an integral representation of a function by means of a smoothing kernel function by involving a finite particle distribution in the discrete formulation. The first approach is derived by the variational formulation of the equilibrium equation, while the second one is a direct differential method. Numerical examples on the cantilever beam problem are implemented to verify and compare the proposed approaches.

Preface to the Special Issue on Nanoconcepts in Energy Chemistry and Catalysis

The demand for a sustainable development of our society requires a fundamental turn in the current approach to energy production and use,which requires developing new concepts and technologies for catalysis in energy chemistry and environmental protection.Realize this challenge requires new materials,new technologies and new processes that can bring about a revolutionary change in our daily life.

Preface to Special Issue on Carbon Materials for Energy Application

The rising cost and limited availability of fossil fuels, and the increasing concerns related to their role on global pollution and greenhouse effect have pushed considerably the need to accelerate the transition to a more sustainable use of energy based largely on renewable energy sources. Nanocarbon materials play a critical role in this transition, as they are the key materials for components of different devices necessary in enabling this transition （batteries, fuel cells, solar cells, etc.）. This issue collects 22 contributions, including one perspective and six review papers on the topic of carbon materials for energy applications, written by well-known experts in this field. It is really an exciting special issue that gives a very updated view of this topic, as well as trends and outlooks in this breakthrough research area. The initial perspective paper introduces the different possibilities offered from the growing level of knowledge in this area, testified from the exponentially rising number of publications. It also discusses the basie concepts for a rational design of these nanomaterials. The lk）llowing six reviews address different specific aspects of synthesis, characterization and use of carbon nanomaterials, from fuel cells to composite electrodes, supercapacitors and photoelectrochemical devices for CO2 conversion. These reviews represent an unique opportunity for the readers to be updated on the latest developments of new carbon families such as fullerene, grapbene, and carbon nanotube, and their derived nanocarbon materials （from carbon quantum dots to nanohorn, nanofiber, nano ribbon, etc.）. Second generation nanocarbons, including modification of these nanocarbons by surface functionalization or doping with heteroatoms to create specific tailored properties, and nanoarchitectured supramolecular hybrids, are also discussed. Finally, 1 communication and 14 full articles discuss several aspects of the use of these nanocarbon materials to develop new catalysts for a range of applications （from biomass conversion to Fisher-Tropsch reaction and electrochemical devices） and new materials for energy storage and conversion （adsorption pumps, Li-ion and Li-S batteries, electrodes for electrochemical uses）. We thus believe that this special issue dedicated to the use and development of carbon materials for energy applications represents a unique occasion for young and experienced researchers as well as for managers in the field of sustainable energy to have an updated view on this enabling topic for the future of our society. We thus invite all to have this special issue as a privileged component of your bookshelf.

Mutiparametric Characterization of Atmospheric Particulate in a Heavy-Polluted Area of South Italy

To obtain a real-time image of atmospheric particulate matter (PM) in highly polluted areas and to understand how the anthropogenic component linked to urban activities (industrial activities, domestic heating, road traffic, waste disposal) can locally affect near-surface measurement of PM, several measurement campaigns were achieved in the Campania region (Southern Italy) using both Lidar and in-situ instruments. A comparison between the obtained results highlights a good correlation between the data and the potential of remote sensing instruments for air quality monitoring. Data analysis was performed in terms of particle backscattering coefficient profile at 355 nm, PM mass concentration, and size distribution. Wind profiles, which covered a range of altitudes from 40 m to 290 m, were also used to study sources and physical processes involved. Measurement carried out in a rural area with a landfill site highlighted the presence of a homogeneous particulate layer throughout the sounded area due to winds driving aerosol from the landfill to the surrounding areas. The size distribution in mass concentration, highlighted a modal diameter moving towards 0.9 and 2 μm with a larger mass concentration of particles in the morning, before noon and in the afternoon when a large number of trucks delivered solid wastes. Moreover, large concentrations of particulate matter were measured in a small urban town with few industrial activities which peak (211 ± 33 μg·m-3) was measured in the direction of the most urbanized area, probably due to the lighting of the domestic heating systems. Bimodal size distribution in number concentration was measured, indicative of two types of atmospheric particles sources: gas and liquid combustion (particles with sizes below 80 nm), including vehicular traffic and domestic gas-heating, and biomass combustion (particles with sizes of the order of 200 - 500 nm). Finally, data collected in a highly populated and industrialized area highlights the presence of particles having a high level of spherical geometry (aerosol depolarization below 5%) pointing towards the industrial area. Conversely, the measurements performed pointing toward other directions highlighted a diffused source of aspherical particles (depolarization values of about 3%) spreading throughout all city territory. The work showed as the co-location of remote sensing and near surface instruments is a promising approach to studying aerosol properties in the atmospheric layers and has more accurate information on atmospheric dynamics. Moreover, the correlation between the obtained results highlighted the potential of remote sensing instruments for air quality monitoring.

Experimental characterization and CFD simulation of gas maldistribution in turbulent fluidization of Group A particles

The study presented hereby investigates experimentally and with CFD simulations the gas distribution effect on the hydrodynamic of a Geldart Group A turbulent fluidized bed. Experiments were carried out on a cold flow fluidized bed column with an even and uneven gas distribution. Local solid volume fraction profiles were measured using optical probes at different bed heights and along two radial directions. Optical probe measurements allow catching a clear hydrodynamic difference between both even and uneven gas distributions. These results were then used to assess CFD simulations with the code Barracuda^(TM) (MP-PIC approach). It is noteworthy that the choice of drag correlation and boundary conditions strongly influences the agreement between the experimental and CFD results. Once the correct parameters are chosen, CFD simulations captured the effect of gas distribution changes.

Digital holography as metrology tool at micronanoscale for soft matter

The appearance of the first laser approximately 12 years after the invention of holography by Gabor(1948)revolutionized the field of optical metrology.In fact,the invention of holographic interferometry enabled the exploitation of interferometry on non-mirror surfaces and full-scale objects.The holography-based measurement methods has been implemented to several industrial systems or in support of R&D with the aim of improving new products in many fields(automotive,aerospace,electronics,etc.).To date,holography has been considered an important measurement tool for non-destructive inspection(NDI),strain-stress measurement,and vibration analysis at various engineering sites.Recently,the new paradigm of Industry4.0 has seen the introduction of new technologies and methods of processing materials as well as the development of manufacturing approaches for the realization of innovative products.For example,direct printing,additive,and bottom-up manufacturing processes are expected to involve new ways of making products in future,and most innovative fabrication processes will be based on the manipulation of soft matter(e.g.,starting from the liquid phase)that will be shaped at the nanoscale.The inherent characteristics of digital holography(DH)make it a powerful and accurate tool for the visualization and testing of final products,as well as for in situ and real-time monitoring and quantitative characterization of the processes involved during the fabrication cycle.This review aims to report on the most useful applications of soft matter,where the capabilities offered by DH,such as three-dimensional(3D)imaging,extended focus,3D tracking,full-field analysis,high sensitivity,and a wide range of measurements from nanometers to centimeters,permit completely non-invasive characterizations on a full-scale.Several holographic experimental results of typical samples are reported and discussed where DH plays a primary role as a tool gauge for soft matter.

Application of flame-formed carbon nanoparticle films for ethanol sensing Author links open overlay panel

Carbon nanoparticles(CNPs)have received considerable attention due to their exceptional qualities and adaptability.Their unique physical and chemical characteristics make them extremely intriguing as materials for numerous high-potential applications,such as electronics and gas sensing.This study focused on producing carbon-based nanomaterial devices by deposition of flame-formed carbon nanoparticles on a suitable substrate and investigating their gas-sensing properties.CNPs were produced in a fuel-rich laminar premixed ethylene/air flame and the collected CNP film was morphologically and electrically characterized.The electrical conductivity of the film was investigated as a function of ethanol concentration and amount of deposited material.Notably,CNP films exhibited high sensitivity to ambient ethanol gas concentrations,and rapid recovery times at room temperature,and showed a sensitivity increasing with the amount of deposited material and the surface complexity.Our findings demonstrate the high potential of combustion-generated CNPs as building materials for low-cost and portable ethanol sensors.

Silver impregnated carbon for adsorption and desorption of elemental mercury vapors

The Hg 0 vapor adsorption experimental results on a novel sorbent obtained by impregnating a commercially available activated carbon （Darco G60 from BDH） with silver nitrate were reported.The study was performed by using a fundamental approach,in an apparatus at laboratory scale in which a synthetic flue gas,formed by Hg 0 vapors in a nitrogen gas stream,at a given temperature and mercury concentration,was flowed through a fixed bed of adsorbent material.Breakthrough curves and adsorption isotherms were obtained for bed temperatures of 90,120 and 150°C and for Hg 0 concentrations in the gas varying in the range of 0.8–5.0 mg/m 3 .The experimental gas-solid equilibrium data were used to evaluate the Langmuir parameters and the heat of adsorption.The experimental results showed that silver impregnated carbon was very effective to capture elemental mercury and the amount of mercury adsorbed by the carbon decreased as the bed temperature increased.In addition,to evaluate the possibility of adsorbent recovery,desorption was also studied.Desorption runs showed that both the adsorbing material and the mercury could be easily recovered,since at the end of desorption the residue on solid was almost negligible.The material balance on mercury and the constitutive equations of the adsorption phenomenon were integrated,leading to the evaluation of only one kinetic parameter which fits well both the experimentally determined breakthrough and desorption curves.

Light Electrospun Polyvinylpyrrolidone Blanket for Low Frequencies Sound Absorption

Light polymeric soundproofing materials （density = 63 kg/m3） of interest for the transportation industry were fabricated through electrospinning. Blankets of electrospun polyvinylpyrrolidone （average fiber diameter = （1.6 ± 0.5） or （2.8 ± 0.5） μm） were obtained by stacking disks of electrospun mats. The sound absorption coefficients were measured using the impedance tube instrument based on ASTM E1050 and ISO 10534-2. For a given set of disks （from a minimum of 6） the sound absorption coefficient changed with the frequency （in the range 200-1600 Hz） following a bell shape curve with a maximum （where the coefficient is greater than 0.9） that shifts to lower frequencies at higher piled disks number and greater fiber diameter. This work showed that electrospinning produced sound absorbers with reduced thickness （2-3 cm） and excellent sound-absorption properties in the low and medium frequency range.

Liquid suspensions of single and binary component solid particles-An overview

In this paper theoretical approaches and experimental findings relative to the hydrodynamics of liquid suspensions of solid particles by liquids are reported and discussed. For the single particle specie systems, advantages and possible faults of well known empirical correlations are discussed. For binary-solid mixture suspensions, experimental evidence are reviewed and approaches capable of successfully describing observed behaviour are reported.

Quantitative imaging of the complexity in liquid bubbles’evolution reveals the dynamics of film retraction

The dynamics and stability of thin liquid films have fascinated scientists over many decades.Thin film flows are central to numerous areas of engineering,geophysics,and biophysics and occur over a wide range of lengths,velocities,and liquid property scales.In spite of many significant developments in this area,we still lack appropriate quantitative experimental tools with the spatial and temporal resolution necessary for a comprehensive study of film evolution.We propose tackling this problem with a holographic technique that combines quantitative phase imaging with a custom setup designed to form and manipulate bubbles.The results,gathered on a model aqueous polymeric solution,provide unparalleled insight into bubble dynamics through the combination of a full-field thickness estimation,threedimensional imaging,and a fast acquisition time.The unprecedented level of detail offered by the proposed methodology will promote a deeper understanding of the underlying physics of thin film dynamics.

Hollow micro- and nano-particles by gas foaming

This paper presents the results of a first successful attempt to produce hollow micro- and nano-particles of a large variety of materials, dimensions, shapes and hollow attributes by using an environmentally friendly and cheap technology, common in polymer processing and known as gas foaming. The central role played by ad hoc polymeric hollow micro- and nano-particles in a variety of emerging applications such as drug delivery, medical imaging, advanced materials, as well as in fundamental studies in nanotechnology highlights the wide relevance of the proposed method. Our key contribution to overcome the physical lower bound in the micro- and nano-scale gas foaming was to embed, prior to foaming, bulk micro- and nano-particles in a removable and deformable barrier film, whose role is to prevent the loss of the blowing agent, which is otherwise too fast to allow bubble formation. Furthermore, the barrier film allows for non-isotropic deformation of the particle and/or of the hollow, affording non-spherical hollow particles. In comparison with available methods to produce hollow micro- and nano-particles, our method is versatile since it offers independent control over the dimensions, material and shape of the particles, and the number, shape and open/closed features of the hollows. We have gas- foamed polystyrene and poly-（lactic-co-glycolic） acid particles 200 ~m to 200 nm in size, spherical, ellipsoidal and discoidal in shape, obtaining open or closed, single or multiple, variable in size hollows.

Dehydration of plant cells shoves nuclei rotation allowing for 3D phase-contrast tomography

Single-cell phase-contrast tomography promises to become decisive for studying 3D intracellular structures in biology.It involves probing cells with light at wide angles,which unfortunately requires complex systems.Here we show an intriguing concept based on an inherent natural process for plants biology,i.e.,dehydration,allowing us to easily obtain 3D-tomography of onion-epidermal cells’nuclei.In fact,the loss of water reduces the turgor pressure and we recognize it induces significant rotation of cells’nuclei.Thanks to the holographic focusing flexibility and an ad-hoc angles’tracking algorithm,we combine different phase-contrast views of the nuclei to retrieve their 3D refractive index distribution.Nucleolus identification capability and a strategy for measuring morphology,dry mass,biovolume,and refractive index statistics are reported and discussed.This new concept could revolutionize the investigation in plant biology by enabling dynamic 3D quantitative and label-free analysis at sub-nuclear level using a conventional holographic setup.

Silk-ELR co-recombinamer covered stents obtained by electrospinning

In the field of tissue engineering the choice of materials is of great importance given the possibility to use biocompatible polymers produced by means of biotechnology.A large number of synthetic and natural materials have been used to this purpose and processed into scaffolds using Electrospinning technique.Among materials that could be used for the fabrication of scaffold and degradable membranes,natural polymers such as collagen,elastin or fibroin offer the possibility to design structures strictly similar to the extracellular matrix(ECM).Biotechnology and genetic engineering made possible the advent of a new class of biopolymers called protein-based polymers.One example is represented by the silk-elastin-proteins that combine the elasticity and resilience of elastin with the high tensile strength of silk-fibroin and display engineered bioactive sequences.In this work,we use electrospinning technique to produce a fibrous scaffold made of the corecombinamer Silk-ELR.Obtained fibres have been characterized from the morphological point of view.Homogeneity and morphology have been explored using Scanning Electron Microscopy.A thorough study regarding the influence of Voltage,flow rate and distance have been carried out to determine the appropriate parameters to obtain the fibrous mats without defects and with a good distribution of diameters.Cytocompatibility has also been in vitro tested.For the first time we use the co-recombinamer Silk-ELR for the fabrication of a 2.5 angioplasty balloon coating.This structure could be useful as a coated scaffold for the regeneration of intima layer of vessels.