Search

The growing need of multifunctional materials with tailor made properties led in the last decades to the development of novel commercial polymer blends, possessing superior physical properties with respect to traditional matrices and showing economical advantages with respect to the synthesis of new plastics. Due to the progressive increase of the environmental concerns on the management of plastic wastes, the difficulties in the sorting technologies and the limited chemical compatibility between the greatest part of polymer pairs, the technical potential of polymer blends often remains unexploited when the recycling stage is considered. In some cases, also the addition of compatibilizers to recycled blends does not represent a satisfactory solution to retain and/or tailor their properties. The aim of this review is that to perform a critical analysis of the potentialities of polymer blends recycling. After an introductive section on the problems and the definitions of plastics recycling, some basic concepts about the physical behaviour of polymer blends are reported. The third section of the review is focused on the analysis of the mechanical recycling of polymer blends, and a general distinction between recycling techniques applied to compatible and un-compatible polymer blends is performed. In this chapter, also the analysis of the recycling potential of commingled plastics deriving from unsorted wastes and of the effect of the thermal reprocessing on the morphological and thermo-mechanical behaviour of polymer blends is reported. Considering the increasing importance of bioplastics in the modern society, the fourth chapter of this review is focused on the mechanical and chemical recycling of blends containing bioplastics, with particular attention to polylactic acid (PLA) and thermoplastic starch (TPS) based blends. The key aspects of the recycling technologies applied to polymer blends and the future perspectives are summarized in the last section of the review.

For many decades, researchers have been working on finding innovative and sustainable solutions to address the enormous quantities of plastic waste that are produced every year which, after being collected, are transformed into energy, recycled, or sent to landfills. Giving a second life to plastic waste as a material to be incorporated, in the form of macro-fibres, into concrete, could be one such solution. The purpose of this study was to analyse the mechanical and physical behaviour of the hardened concrete reinforced with macro plastic fibres (RPFs) obtained from food packaging waste (FPW) discarded during the packaging phase. By varying the quantity of macro-fibres used, physical and mechanical properties such as compressive strength, modulus of elasticity, flexural strength, and toughness were evaluated. It was observed that, although the presence of macro plastic fibres reduced the mechanical resistance capacity compared to that of traditional concrete, their contribution proved to be of some importance in terms of toughness, bringing an improvement in the post-crack resistance of the composite material. This innovative mixture provides a further impulse to the circular economy.

The goal of this study was to analyze the physical properties of metalized and non metalized cast PolyPropylene (CPP) plastic films with respect to its degradation and environmental pollution. The PP films of 20 microns were produced by standard cast film extrusion process i.e. metalized PP films coated by aluminium and others without any coating. The samples were manufactured at an industry which produces food grade plastics made by a cast co-extrusion process. Physical properties like Tensile strength, Oxygen transmission rate and water vapour transmission rate measured as per ASTM standard. Results show that non-metallized film has a range of WVTR 6-8g/m2/day and OTR range 2300-2500cc/m²/atm/day. However, metalized PP film shows about 50% to 80%improvement in the OTR and WVTR. It has been proven that metallization with aluminium has improved the physical properties but affect the rate of degradation. In the current study, the extent of degradation of plastic by fungal colonization(Aspergillus and Pencilliumspp) was measured by the structure investigation using FTIR spectroscopy, results indicate fewer changes in the peak after exposed to the fungi in synthetic media. The spectrum peak in the control on non-metalized film observes at 37736 cm-1, 38913 cm-1 and 6742 cm-1, which are absent after degradation. Similarly in metalized plastic peaks at 3779.8 cm-1, 3771.1 cm-1 , 2357.2 cm-1 and 2007.2 cm-1 were disappeared after degradation. This variation in peaks indicates fungi use the plastic as the source of carbon. These samples were tested for their degradation properties with respect to the physical properties. Both samples took for 30 days of degradation. It is found that non-metalized films degraded effectively in the mean period of time.

Uncertainty in nuclear reaction cross sections, angular distributions, and other nuclear data directly impact how well simulations of nuclear systems represent physical observations. To determine how well the nuclear data in ENDF/B-VIII.0, JEFF-3.3, and JENDL-4.0 evaluations describe the physical behaviour of 235U, and 239Pu when subjected to a neutron flux, the neutron emission spectrum was measured for carbon, 93.0% 235U, and 93.9% 239Pu samples, and compared against detailed MCNP6 simulations. The measurements were performed at the Los Alamos Neutron Science Center using a quasi-differential method previously developed at Rensselaer Polytechnic Institute. The measurement spanned 0.82–20 MeV and 30–150 degrees. The measurements show there are a significant number of discrepancies between library predictions of the neutron yield and physical observation. A few of the main discrepancies found are described in this paper. Based on these results a new evaluation utilizing these results for carbon, 235U, and 239Pu is recommended.

The correlation between calcination temperature with the morphological, porosity and density of Sm0.5Sr0.5CoO3−δ/ Sm0.2Ce0.8O1.9incorporation with binary carbonate prepared by high energy ball milling (HEBM) method has been investigated. The composite cathode, samarium strontium cobaltite-samarium doped ceria carbonate (SSC:SDCc), was developed and scrutinised as for potential cathode materials in solid oxide fuel cell (SOFC) applications. This research studied the influence of carbonate in composite electrolyte, SDCc towards the composite cathode properties. The composition of 50 wt.% of SSC was chosen to be added with 50 wt.% of SDCc powder. The prepared powders of composite cathode SSC5:SDCc5 were then undergone calcination process at different operating temperatures which has been varied from 600°C, 650°C, 700°C and 750°C and all prepared pellets were sintered at 600 °C. The morphological properties of the composite cathode powders were observed via FESEM micrograph, and the average particle sizes of the composite powders were measured via SmartTiff Software. The total porosity (%) of the SSC5:SDCc5 composite cathode pellets was determined using the Archimedes method. The FESEM micrograph revealed that the obtained composite cathode powder is homogeneous, fine with average of agglomerates sizes of 70–100 nm. By increased on calcination temperatures, the agglomerates size of the composite cathode and the density of the pellet increased. Meanwhile the results collected from porosity value are decreased. The porosity percentage lies in the range from 32.3% until 38.7%. Based on the overall results, lower calcination temperature, which is 600° lead to better morphological and physical results. In conclusion, the calcination temperature has a direct effect on the average size of SSC-SDCc composite cathode, porosity and density value but still in line within the acceptable range to serve as effective potential cathode materials for solid oxide fuel cells.

El presente artículo tiene como objetivo evaluar el comportamiento físico mecánico del hormigón con productos derivados de la caña de azúcar tales como (1) la ceniza de bagazo de caña de azúcar (CBCA) como reemplazo porcentual y gradual del cemento; y (2) la fibra de bagazo de caña de azúcar (FBCA) como reemplazo porcentual respecto al peso del agregado. Se revisó 46 artículos científicos referidos al tema entre la base de datos SCOPUS y SciELO, cuyos resultados encontrados fueron que al incorporar entre el 20% al 30% de CBCA incinerada entre 600ºC y 800 ºC mejora sustancialmente la trabajabilidad, resistencia a la compresión y flexión; por otra parte la incorporación de FBCA tratada (lavada y sumergida en hidróxido de calcio) en porcentajes que van del 0.5% al 1.5% respecto al peso del agregado, mejora también las propiedades de resistencia principalmente.

Background Studies have seldom used Compositional Data Analysis (CoDA) to map the effects of sleep, sedentary behaviour, and physical activity on older adults’ cardio-metabolic profiles. This study therefore aimed to illustrate how sleep, sedentary behaviour, and physical activity profiles differ between older adult groups (60–89 years), with ‘low’ compared to those with ‘high’ concentrations of endocrine cardio-metabolic disease risk markers, using CoDA. Method Ninety-three participants (55% female) wore a thigh-mounted triaxial accelerometer for seven consecutive free-living days. Accelerometer estimates of daily average hours of engagement in sedentary behaviour (SB), standing, light-intensity physical activity (LIPA), sporadic moderate-vigorous physical activity (sMVPA, accumulated with bouts between 1 and 10 min), 10-min moderate-vigorous physical activity (10MVPA, accumulated with bouts ≥10 min), in addition to self-reported sleeping hours were reported. Fasted whole blood concentrations of total cholesterol, triglyceride, glucose, and glycated haemoglobin, and serum lipoprotein lipase (LPL), interleukin-6 (IL-6), and procollagen III N-terminal propeptide were determined. Results Triglyceride concentration appeared to be highly dependent on 10MVPA engagement as the ‘low’ and ‘high’ concentration groups engaged in 48% more and 32% less 10MVPA, respectively, relative to the geometric mean of the entire study sample. Time-use composition of the ‘low’ LPL group’s engagement in 10MVPA was 26% less, while the ‘high’ LPL group was 7.9% more, than the entire study sample. Time-use composition of the ‘high’ glucose and glycated haemoglobin groups appeared to be similar as both engaged in more Sleep and SB, and less 10MVPA compared to the study sample. Participants with a ‘low’ IL-6 concentration engaged in 4.8% more Sleep and 2.7% less 10MVPA than the entire study sample. Time-use composition of the Total Cholesterol groups was mixed with the ‘low’ concentration group engaging in more Standing and 10MVPA but less Sleep, SB, LIPA, and sMVPA than the entire study sample. Conclusion Older adults should aim to increase 10MVPA engagement to improve lipid profile and decrease SB engagement to improve glucose profile.

Shape memory is the capability of a material to be deformed and fixed into a temporary shape. Recovery of the original shape can then be triggered only by an external stimulus. Shape-memory polymers are highly deformable materials that can be programmed to recover a memorized shape in response to a variety of environmental and spatially localized stimuli as a one-way effect. The shape-memory function can also be generated as a reversible effect enabling actuation behaviour through macroscale deformation and processing, specifically by dictating the macromolecular orientation of actuation units and of the skeleton structure of geometry-determining units in the polymers. Shape-memory polymers can be programmed and reprogrammed into arbitrary shapes. Both recovery and actuation behaviour are reprogrammable. In this Review, we outline the common basis and key differences between the two shape-memory behaviours of polymers in terms of mechanism, fabrication schemes and characterization methods. We discuss which combination of macromolecular architecture and macroscale processing is necessary for coordinated, decentralized and responsive physical behaviour. The extraction of relevant thermomechanical information is described, and design criteria are shown for microscale and macroscale morphologies to gain high levels of recovered or actuation strains as well as on-demand 2D-to-3D shape transformations. Finally, real-world applications and key future challenges are highlighted. Shape-memory materials can generate programmable movements triggered by an external stimulus, such as an environmental change. In this Review, the authors discuss mechanisms, fabrication schemes, characterization methods and applications of the one-way shape-memory effect enabling shape recovery and of reversible shape-memory effects exhibiting actuation behaviour.

The importance of stereochemistry to the function of molecules is generally well understood. However, to date, control over stereochemistry and its potential to influence properties of the resulting polymers are, as yet, not fully realized. This Review focuses on the state of the art with respect to how stereochemistry in polymers has been used to influence and control their physical and mechanical properties, as well as begin to control their function. A brief overview of the synthetic methodology by which to access these materials is included, with the main focus directed towards the effect of stereochemistry on mechanical properties, biodegradation and conductivity. In addition, advances in applications of stereodefined polymers for enantioseparation and as supports for catalysts in asymmetric transformations are discussed. Finally, we consider the opportunities that the rich stereochemistry of sustainably sourced monomers might offer in this field. Where possible, we have drawn parallels between design principles in order to identify opportunities and limitations that these approaches may present in their effects on materials properties, performance and function. Changes in the stereochemistry of polymer chains result in changes to the mechanical and physical behaviour of the resulting materials. By harnessing synthetic methods to create stereocontrolled polymers, a new parameter can be accessed to control the behaviour of bulk material.

Viruses are very efficient in the delivery of their viral DNA or RNA into cells. Using them as DNA/RNA delivery tools in the lab or in medicine (e.g. gene therapy), however, brings safety issues. Therefore, we designed our own artificial virus. The artificial virus is composed of a simple protein, designed by us, that can bind and fully coat strands of DNA and RNA. Within such an artificial virus particle, the DNA is protected against degradation, potentially allowing it to be delivered into cells. In this thesis, we studied the physical behaviour of these self-designed proteins and used that information to improve their design for delivery into cells. In addition, we made a first effort to design the protein in such a way that it can coat specific DNA strands.

In recent years, the versatile coordinating nature and facile construction of mixed donor (O, N, S) acyl(aroyl)thiourea ligands has led to the design and synthesis of new photo-active, macrocyclic and heteroleptic complexes. Although a significant portion of the structure, synthesis and application of acylthioureas has been reviewed in the literature, this article sheds light on recent advances related to the use of acylthioureas and its derivatives as versatile ligands in the field of coordination chemistry. In particular, there has been significant progress in the preparation and study of the elusive trans-[M(L-κS,O)2] complexes prepared by photo-irradiation of corresponding cis-[M(L-κS,O)2] complexes (M = Pt(II) and Pd(II)) in solution state. A fundamental insight into the photo-active behaviour of such complexes has immense scope since their structural and physical behaviour is less explored and thus studies on the kinetics and mechanism of trans → cis isomerism is highlighted. In addition, new results obtained from spectroscopic studies of the cis/trans-[Pt(L-κS,O)2] complexes using 195Pt{1H} NMR are presented. Furthermore, the use of bipodal acylthiourea analogues as building blocks in the synthesis and design of new coordination-driven metallacycles and metallacages has seen renewed interest in the last decade. While this article does not elaborate on synthetic details, it summarizes the current collection of known acylthiourea supramolecular compounds and also includes important structural information as well as some notable properties (such as magnetism, vapochromism, bio-applications and guest–host chemistry).

In the occasion of the celebrations for the 150th anniversary of the founding of Italy (1861-2011), it was decided to analyse the artwork "The Italian Flag" (La Bandiera Italiana) created by the artist Fernando Melani (Pistoia, 1907-1985), one of the precursors of the Poor Art artistic movement in Italy. This project is a follow-up to a previous study which was mainly focused on the pigments and dyes found in his home-studio. The main goal of this paper is to identify a correct diagnostic plan, based on the use of a combination of non-invasive and micro-invasive methodologies, in order to determine the state of preservation and define the best conservation procedures for a contemporary artwork. Visible, infrared and infrared false colour images as well as the Fibre Optic Reflectance Spectroscopy (FORS) technique were applied in situ to analyse The Italian Flag. Laser Induced Breakdown Spectroscopy (LIBS), Fourier Transform Infrared (FT-IR) and micro-Raman spectroscopies, Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS), High Performance Liquid Chromatography with Diode Arrays Detection (HPLC-DAD) and Mass Spectrometric Detection (HPLC-ESI-Q-ToF) were all applied to three small samples detached from the three painted (green-blue, white and red-yellow, respectively) areas of the flag. The combination of the data obtained with all these techniques made possible a comprehensive understanding of both the chemical composition and physical behaviour of the materials used by the artist and supported curators in defining the preventive conservation of this artwork.

In the modern product development process, 3D printing is emerging as a novel technology for rapid manufacturing of components with complex geometries. Thermoplastic polymers are widely being 3D printed, however due to their poor mechanical properties there is a growing need for polymer composites which possess better performance. The favourable properties offered by nanocomposites have led to shift in focus towards development and characterisation of various nanocomposites. In this paper, studies directed towards nanocomposites processed via fused deposition modelling method have been reviewed. The effect of various reinforcing agents and various process parameters on mechanical properties of these nanocomposites has been presented. The literature suggests that additive manufacturing has tremendous potential in improving the properties of the polymeric composites. Moreover, the 3D printing technology is flexible enough to shorten the product development time. However, the effect of various process parameters on the mechanical properties needs to be studied in detail.

Starch accumulates in plants as granules in chloroplasts of source organs such as leaves (transitory starch) or in amyloplasts of sink organs such as seeds, tubers and roots (storage starch). Starch is composed of two types of glucose polymers: the essentially linear polymer amylose and highly branched amylopectin. The amylose content of wheat and rice seeds is an important quality trait, affecting the nutritional and sensory quality of two of the world's most important crops. In this review, we focus on the relationship between amylose biosynthesis and the structure, physical behaviour and functionality of wheat and rice grains. We briefly describe the structure and composition of starch and then in more detail describe what is known about the mechanism of amylose synthesis and how the amount of amylose in starch might be controlled. This more specifically includes analysis of GBSS alleles, the relationship between waxy allelic forms and amylose, and related quantitative trait loci. Finally, different methods for increasing or lowering amylose content are evaluated.

BACKGROUND: It has been advocated that older adults should concomitantly spend less time in sedentary behaviour (SB), and engage in sufficient physical activity (PA), to reduce their risk of cardio-metabolic diseases. However, it is not clear what intensity of PA must be done to offset SB engagement. AIM: Model how cardio-metabolic profiles could change if older adults replaced an hour per day (hr·day-1) of a physical behaviour intensity with 1 hr·day-1 of another physical behaviour of a different intensity. METHODS: Older adults (n = 93, 60-89 years old, 55% female) wore a thigh-mounted triaxial accelerometer for seven consecutive free-living days to estimate mean daily hourly engagement in SB, Standing, Light Intensity PA (LIPA), sporadic moderate to vigorous physical activity (sMVPA, bouts

The absorption and emission spectra of fluorescent thiophene dye, namely, 2,5-di-(5-tert-butyl-2-benzoxazolyl) thiophene, have been recorded at room temperature in solvents of different polarities. The excited state dipole moments ( e) were estimated from Lippert’s, Bakhshiev’s, and Kawski–Chamma–Viallet’s equations using the variation of Stoke’s shift with the solvent dielectric constant and refractive index. The optimized geometry of themolecule and gwere calculated theoretically by Gaussian 03 software using B3LYP/6-31g* level of theory. The g and ewere calculated bymeans of solvatochromic shift method and ewas determined in combination with g. It was observed that ewere higher than those of the g, indicating a substantial redistribution of the -electron densities in a more polar excited state for the selected thiophene dye. Further, the change in the dipole moment ( ) was calculated both from solvatochromic shift method and on the basis of microscopic empirical solvent polarity parameter ET N and values are compared. PACS Nos.: 33.50.−j, 87.64.i, 31.70.Hq, 87.15.kg. Resume : Nous avons enregistre, a la temperature de la piece et dans des solvants de differentes polarites, les spectres d’absorption et d’emission du colorant thiophene fluorescent 2,5-di-(5-tertbutyl-benzoxazolyl). Nous estimons le moment dipolaire ( e) des etats excites a partir des equations de Bakhshiev et Kawski–Chamma–Viallet en utilisant la variation du deplacement de Stokes, avec la constante dielectrique du solvant et l’indice de refraction. La geometrie de lamolecule est completement optimisee et nous calculons g a l’aide du logiciel Gaussian 03 utilisant le modele theorique B3LYP/6-31g*. Les parametres g et e sont calcules par lamethode du deplacement solvatochromique et e est determine en combinaison avec g. Nous observons que les valeurs de e sont plus elevees que celles de g, ce qui indique une redistribution substantielle des densites d’electrons dans un etat excite plus polaire pour le colorant thiophene choisi. De plus, nous evaluons les changements dumoment dipolaire ( ) a partir de deux methodes, celle du deplacement solvatochromique et sur la base d’un parametre de polarite empirique microscopique ET N et nous comparons ensuite les resultats. [Traduit par la Redaction]

As the development of more advanced capture and storage technologies continues along with gradual scale-up of demonstration projects, the imminent deployment of commercial-scale carbon capture and storage is becoming increasingly likely. The transport stage needs to undergo similar development as there is much that needs to be better understood. In particular, there is a need for an equation of state which can accurately describe the physical behaviour of mixtures of carbon dioxide with impurities during the transport stage of carbon capture and storage in a simple, effective way. Presented here is the early development of a new, analytic equation of state, specifically designed to be highly accurate within the window 0 to 30.9782 ℃ and up to 150 bar (the anticipated usual region of operation for carbon capture and storage pipelines). In this paper, the potential of the proposed equation of state is demonstrated with descriptions for the pressure (from which density can be directly calculated) and phase behaviour of pure CO2. Comparisons with the Peng–Robinson equation of state are made in order to demonstrate the potential of the model, which has both simplicity similar to that of the Peng–Robinson equation and accuracy similar to that of the Span–Wagner equation. Presently, it is found that inside this window, the maximum percentage error of the new equation in the description of pressure for the case of pure carbon dioxide is not more than approximately 2.53%, compared with 40.85% for the Peng–Robinson equation, whilst for the description of phase behaviour, it is not more than 2.41%, compared with 18.23% for the Peng–Robinson equation.

This paper reviews information from the existing literature and the EU GMOS (Global Mercury Observation System) project to assess the current scientific knowledge on global mercury releases into the atmosphere, on global atmospheric transport and deposition, and on the linkage between environmental contamination and potential impacts on human health. The review concludes that assessment of global sources and pathways of mercury in the context of human health is important for being able to monitor the effects from implementation of the Minamata Convention targets, although new research is needed on the improvement of emission inventory data, the chemical and physical behaviour of mercury in the atmosphere, the improvement of monitoring network data, predictions of future emissions and speciation, and on the subsequent effects on the environment, human health, as well as the economic costs and benefits of reducing these aspects.

In France, about 450 km of high-speed lines (HSL) are potentially subject to drain scaling problem. A HSL site affected by calcite scaling was continuously monitored for 20 months to follow the phenomenon and also to estimate the monthly calcite precipitation rate. Drain water samples were also monthly analyzed and show high calcium and sulphate concentrations. The high sulphate concentration (~6 mM) highlights the dissolution of gypsum in the drain environment. Based on the material analysis (X-ray diffraction), gypsum is present in the subballast and capping layer. Since the drain system is a multi-environments system, and based on multi-phase reactions, the study is divided into two parts: a physical one (transport of water in the system) and a chemical one (transport of the reactants in the system). The physical processes have an essential impact on the chemical precipitation processes. In the present paper, on the basis of the collected data, the physical behaviour of the experimental site (water circulation) will be presented in the first step and used in the further chemical process study. The monthly calcite precipitation rate and quantities are given as well.

Sucrose is probably one of the most studied molecules by food scientists, since it plays an important role as an ingredient or preserving agent in many formulations and technological processes. When sucrose is present in a product with a concentration near or greater than the saturation point—i.e. in the supercooled state—it possesses high potentialities for the food industry in areas as different as pastry industry, dairy and frozen desserts or films and coatings production. This paper presents a review on critical issues and research on highly concentrated sucrose solutions—mainly, on sucrose thermal degradation and relaxation behaviour in such solutions. The reviewed works allow identifying several issues with great potential for contributing to significant advances in Food Science and Technology., Authors are grateful for the valuable discussions with Teresa S. Brandao and Rosiane Lopes da Cunha during this research. Author M. A. C. Quintas acknowledges the financial support of her research by FCT grant SFRH/BPD/41715/2007.

PurposeThe purpose of this paper is to present an update on the progress of the design and reliability of stretchable interconnections for electronic circuits.Design/methodology/approachFinite element modelling (FEM) is used to analyse the physical behaviour of stretchable interconnects under different loading conditions. The fatigue life of a copper interconnect embedded into a silicone matrix has been evaluated using the Coffin‐Manson relation and FEM.FindingsThe mechanical properties of the substrate and the design of the metal interconnection play an important role on the fatigue lifetime of circuit. In the case of copper embedded into a PDMS Sylgard 186, more than 2,500 tensile cycles have been observed for a periodic deformation of 10 per cent.Research limitations/implicationsReliability results are limited and need further work to create a more accurate empirical model to estimate the lifetime of stretchable interconnections.Originality/valueThe combined use of FEM and experimental analysis enable a more reliable design of the stretchable metal interconnections. The proposed horseshoe design offers the benefit of reduced permanent damage during elongation.

A theoretical model explaining the CO 2 sensing mechanism of BaTiO 3 –CuO thin-films is presented. This model is based on the work function variations of the p–n heterojunction that exists between BaTiO 3 (n-type) and CuO (p-type). Impedance measurements are carried out at different carbon dioxide concentrations in order to check the theory exposed and also to show that the Ag as an additive improves the sensor response because a metal–semiconductor junction appears between the silver and the sensing material. Response to CO 2 at different working frequencies and the relation between response and the spatial-charge and relaxation phenomena are also presented.

From theoretical considerations, an expression has been derived for the instantaneous temperature distribution in an ion-exchange column. The theory predicts a ‘hot spot’ which will move along the tube with uniform velocity, and whose peak temperature will attain a steady value as it passes along the tube. With increasing concentration of regenerant this steady value increases; the time required to reach this steady value also increases, until at a critical concentration the temperature continues to increase indefinitely. At concentrations exceeding this critical value, the steady value will fall, so that a low maximum temperature is found for both low and high concentrations. Experiments with varying regenerant concentrations confirmed these results regarding the behaviour of the steady value, and agreement between the theoretical and experimental values of the peak velocity was within the limits of experimental error, in the range of concentrations likely in practice. Owing to experimental difficulties in determining the fraction void and in interpreting bed-volume figures and the effects of the swelling that occurs with many resins, quantitative prediction of maximum temperatures and of velocities may not be satisfactory until more information about the physical behaviour of ion-exchangers is available.

Coarse-grained (CG) models are popular alternatives to atomistic (AT) force fields as they enable simulations of larger systems at longer timescales. The bottom-up approach is a systematic parameterisation strategy whereby data from AT simulations are used to determine the CG parameters. This is particular straightforward with the bond and angle parameters as a direct Boltzmann inversion can be used. Still, a reference AT force field has to be chosen. In this study, I compare three common AT force fields (Stockholm lipids, Berger and Gromos) and investigate the sampling of bond and angle distributions in two CG models (Martini and Elba). As a test case, I choose a bilayer of POPC lipids. The AT simulations give distributions that agree to a large extent, especially in the fatty acid tails. However, the AT simulations sample distributions that differ from the distributions observed in CG simulations with respect to both location and width. The bond and angle distributions from the AT simulations are then used to re-parameterise the CG force fields. For the Martini model, this significantly alters the physical behaviour of the membrane, which likely is an effect of the mapping. However, for the Elba model the re-parameterised force field gives a membrane that is in some respects closer to the experimental membrane. Implications for CG parameterisation are discussed.

Thermally-densified hafnium terephthalate UiO-66(Hf) is shown to exhibit the strongest isotropic negative thermal expansion (NTE) effect yet reported for a metal-organic framework (MOF). Incorporation of correlated vacancy defects within the framework affects both the extent of thermal densification and the magnitude of NTE observed in the densified product. We thus demonstrate that defect inclusion can be used to tune systematically the physical behaviour of a MOF., Comment: 8 pages, 4 figures, revised

The paper studies the effect of additives such as calcite, dolomite and sodium chloride on the mineralogical–textural and physical–mechanical behaviour of solid bricks destined for use as new materials in the restoration of historic buildings. The behavioural differences between specimens with and without carbonates can be explained by the different evolution of texture and mineralogical composition developed during the firing process. Carbonates are shown to result in bricks with different mineralogy, depending on firing, but with a stable microstructure within a wide range of temperatures (800–1000 °C). This may be an advantage when manufacturing pottery but these pieces lack mechanical resistance to high temperatures. Salt partially modifies the mineralogy of the bricks, acting as a melting agent, especially at high firing temperatures, and giving rise to more resistant products which are suitable for restoration work.

A Monte Carlo simulation, with the energetics described by the embedded atom method, has been employed to study the physical behaviour of boron atoms during relaxation of the Ni3AlBinfinity grain boundary. It has also been used to calculate not only the peak concentrations of Ni and B and the valley concentration of Al at the grain boundary, but also the dependence of the grain boundary cohesion on the B bulk concentration. During relaxation of impure Ni3Al grain boundaries, we suggest that, as the segregating species, the B atoms either insert into interstices in the grain boundary or substitute Ni atoms. Meanwhile, as the inducing species, they induce Ni atoms to substitute for Al atoms. Calculations show that in the equilibrium, when the B bulk concentration x increases from 0.1 to 0.9, the peak concentration of B increases, the peak concentration of Ni maximizes while the valley concentration of Al minimizes at x = 0.5. The calculations also show the best cohesion of the grain boundary at x = 0.5.

Highlights • Implicit solvent replaces explicit water by a potential of mean force. • Popular models are SASA, VOL and Generalized Born. • Implicit solvent is used in MD, protein modelling, folding, design, prediction and drug screening. • Large-scale simulations allow for parametrisation via force matching. • Application to nucleic acids and membranes is challenging., We review implicit solvent models and their parametrisation by introducing the concepts and recent devlopments of the most popular models with a focus on parametrisation via force matching. An overview of recent applications of the solvation energy term in protein dynamics, modelling, design and prediction is given to illustrate the usability and versatility of implicit solvation in reproducing the physical behaviour of biomolecular systems. Limitations of implicit modes are discussed through the example of more challenging systems like nucleic acids and membranes.

The present contribution summarizes the most recent results on the synthesis and chemical physical characterization of the new classes of porphyrazine macrocycles having annulated five- and seven-membered heterocyclic rings, i.e. tetrakis(thiadizole)porphyrazine, TTDPzH 2, tetrakis(selenodiazole)porphyrazine, TSeDPzH 2, tetrakis-2,3-(5,7dipheny-6H-1,4-diazepino)porphyrazine, Ph 8 DzPzH 2, and a number of their metal derivatives, prepared by using, respectively, 3,4-dicyano-1,2,5-thiadiazole, 3,4-dicyano-1,2,5-selenodiazole, and 5,7-diphenyl-2,3-dicyano-6H-1,4-diazepine as monomeric precursors. The available information indicates that, owing to the presence of electron rich and soft atoms ( S , Se ) inserted in the proximity of the porphyrazine core, the TTDPz and TSeDPz macrocycles, closely resembling their phthalocyanine analogues in terms of structural and electronic features and physical behaviour (solubility, thermal stability, vaporizability, etc.), might be promising new materials for applicative properties. Particularly interesting is the operated peripheral ring opening of the TSeDPz macroxycle leading to the formation of octaaminoporphyrazine, followed by its conversion to a tetrakis(pyrazino)porphyrazine. The macrocycles containing the Ph 8 DzPz skeleton, due to the presence of the external non planar diphenyldiazepine units, appear to exhibit a distinct physical behaviour, which can be probably modulated by appropriate alternative substitutions in the 5, 6, and 7 positions of the diazepine rings.

Recent studies on physical behaviour of food fats have been reviewed. with an emphasis on solidification properties in bulk and emulsion states. It was shown that the use of synchrotron radiation X-ray beam highlighted the solidification behaviour of polymorphic fats, which was not unveiled by traditional X-ray beams on a laboratory scale as summarised in the following: (a) kinetic processes of molecular ordering of lamella-structured fat crystals. (b) mixing behaviour of different triacylglycerols forming miscible, eutectic, and molecular compound crystals, and (c) remarkable influences of shearing forces on the rapid solidification of the more stable forms of cocoa butter. These results have given some indications to the physical control of fat solidification. and the blending and fractionation of solid fats. The influences of hydrophobic emulsifiers on the solidification of fat crystals in O/W emulsions, which were in-situ monitored by an ultrasound velocity technique, have shown that the addition of highly hydrophobic emulsifiers having long-saturated acid moieties accelerated the nucleation of the fats at the interface areas of the emulsions. These effects are also indicative for the selection of the emulsifier for the control of the fat solidification in the emulsion phases.

A diverse range of foods are aerated, using a similarly varied assortment of processing methods. Aerated foods are generally poorly understood, but are of increasing importance as manufacturers seek to exploit the novelty and versatility of bubbles as food ingredients. Food aeration is one of the fastest growing unit operations, while many ingredients achieve their functionality through their effects at bubble interfaces. This paper reviews the range of aerated foods, and attempts to bring some structure to their diversity by examining different bases for classification. Experimental approaches for characterising aerated foods are discussed. Although food foam chemistry is reasonably well understood, the physical behaviour of bubbles in food systems is less well appreciated. Models describing the dynamic behaviour of bubbles as physical entities are reviewed.

Due to the miniaturization process of the CMOS components metallization structures are becoming more and more complex. Better knowledge to improve via robustness for high current applications is needed. Geometry changes can have a big effect on the physical behaviour. For higher robust metallization systems it is necessary to learn more about overlap design to meet the most economic layout. Slotted high current line layouts do not allow the use of big via areas. Furthermore the number of vias increases the resistance. Investigations have shown the existence of an optimal overlap.

This paper is concerned with the engineering significance of gas hydrates and the possible engineering consequences on seabed installations. A review of physical behaviour of gas hydrate-charged marine soil is presented and the potential influence on the most relevant installations is discussed. Of particular concern are seafloor stability, drilling, sea floor pipelines as well as heavy structures and anchors. A few anecdotal examples of detrimental gas hydrate experienced by the hydrocarbon industry are mentioned. We point to numerous unknown aspects of gas hydrates and call for all means of caution and long term monitoring of engineering structures in hydrate prone areas.

Theoretical considerations tending to explain optical absorption of amorphous CdO in the ultraviolet region are presented. The calculations performed here are based on Burstein-Moss model and they are related to the influence of oxygen partial pressure on the physical behaviour of CdO films. Our theoretical analysis is compared with experimental results reported by some workers.

In this work we analyze the calculation of tlie solubility of salts at high tem- peratures and ~)ressiires. The prediction of so1ul)ility constants relies on the knowledge of the stantlard properties of the ions in water, while the calculation of ion concentration and speciation in solution at saturation requires a niethotl to estimate activity coeffi- cients and association constants. We discuss the achievements and 1iniita.tions of the ion-specific intermtion antl the 1iiea.n spherical iiiodels to estimate activity coefficients in pure and iiiixetl electrolyte systems. We emphasizes the importance of simple models depending on few molecular pa.ranieters and having a reasonable physical behaviour as it function of pressure and temperature.

A comprehensive understanding of both the chemical composition and physical behaviour of modern materials is an important consideration in devising correct conservation treatments for contemporary artworks. To this end, national and international research projects and networks have been established that deal mainly with the preservation, conservation, and understanding of materials used by contemporary artists. This paper focuses on the self-taught artist Fernando Melani (1907–1985), one of the precursors of the Poor Art artistic movement in Italy, and for the first time provides a scientific viewpoint on the artist’s materials and works. The analyses, which mainly focus on the pigments/dyes found in his home-studio, were carried out primarily by using Fourier Transform Infrared Spectroscopy (FT-IR) and ultraviolet, visible, and near-infrared Fibre Optic Reflectance Spectroscopy (UV–Vis–NIR FORS). This paper emphasises the performance of FT-IR and FORS in the identification of contemporary artistic materials, since these two techniques have been found to produce highly complementary data. The use of both of these was required in order to obtain a comprehensive understanding of the composition of Melani’s materials. Furthermore, one of his artworks, named by Melani himself with its inventory number N. Inv. 2625 (1981), was investigated in situ with the sole use of the FORS technique. The results showed that Melani used traditional inorganic pigments as well as modern organic dyes. Calcite and barite were used as fillers and extenders. Sulphur and abrasive powder were also found, thus confirming his use of a large variety of non-conventional artists’ materials.

In this survey, an overview will be given about lanthanide intermetallics studied with rare earth Mossbauer spectroscopy. Results of Pr, Gd, Dy, Er, Tm and Yb compounds will be presented and compared with the emphasis on Pr and Tm results. Crystal field and magnetic interaction and relaxation will be treated to describe the physical behaviour of rare earth compounds.

Since its inception by T. Svedberg and co-workers in the 1920's the technique of analytical ultracentrifugation has undergone an extraordinary evolution, peaking in popularity in the 1950's and 1960's followed by a steady decline until the last few years with a renewal of interest culminating in the launch of a new commercially available instrument. The technique is worthy of consideration by any analytical chemist interested in the characterisation of the physical behaviour of macromolecules in solution. This article attempts to indicate the breadth of the range of different types of measurements on both bio- and synthetic macromolecular systems that are now possible with the analytical ultracentrifuge

In order to adapt the physical properties of living materials to their biological function, nature has developed (polyelectrolytic) polymers with outstanding physical behaviour. Nature provides giant macromolecules (such as actin filaments), which can be directly observed and which comprise the whole range of flexibilities from the random coil to the rigid rod. The structure and dynamics of the macromolecules and networks can be manipulated in many ways by making use of the tricks of nature. In the present contribution some of the most pertinent elements of the intracellular and extracellular matrix are introduced. One main purpose of this contribution is to show that many of these polymers are also of great potential interest in polymer science, in order to study fundamental properties of macromolecules and macromolecular networks. Another intention is to bridge the gap between biological material research and the physics and chemistry of polymers and other complex fluids and to plead for a closer cooperation between the two fascinating worlds.

Acrylamides containing heteroatoms N, S or O are effective compounds to influence the properties of polymers. On the one hand they determine the chemical and physical behaviour of the synthetic materials, on the other hand they offer new possible applications for such compounds. In this paper a synthetic method affording a new class of monomers prepared from simple educts is described. Thus, 3-thiazolines 3 are allowed to react with alkenoyl chlorides (e. g. acryloyl chloride) to give 3-alkenoyl-4-chlorothiazolidines. Upon hydrolysis the 3-alkenoyl-4-hydroxythiazolidines 6a–d, 7a, b, 8a–d and 9a, b are obtained. Starting from 3-alkenoyl-4-chlorothiazolidines, several 3-alkenoyl-4-methoxythiazolidines 6e, f, 7c and 9c have been synthesized, too.

Here we investigate the supramolecular polymerizations of two lipophilic guanosine derivatives in chloroform by light scattering technique and TEM experiments. The obtained data reveal the presence of several levels of organization due to the hierarchical self-assembly of the guanosine units in ribbons that in turn aggregate in fibrillar or lamellar soft structures. The elucidation of these structures furnishes an explanation to the physical behaviour of guanosine units which display organogelator properties.

The effect of ageing temperature (belowTg) on physical ageing of glassy PET has been investigated by differential scanning calorimetry. The position of the glass transition endotherm was found to be strongly dependent on the annealing conditions (time, annealing temperature). A single relaxation time model is proposed for the analysis of physical ageing.

Magnetic phase diagrams of disordered Heisenberg antiferromagnets with mixed uniaxial anisotropy are calculated within a local molecular field theory. The phase diagrams numerically obtained for sets of parameters relevant for the system Fe1-xNixCl2 are in very good agreement with recent experimental results. It is demonstrated that by changing the concentration x, or the ratio of the anisotropies, a rich variety in the physical behaviour of these systems can be expected.

The computer code NACRE originally describing only the physical behaviour of polydisperse aerosol systems has been extended to chemical reactions in the wet phase of droplets. At the moment data for the oxidation of SO 2 by 03 and H,02 are implemented in the code. Sample calculations are presented for the geometry of the planned large scale experiments AIDA showing the interaction between the physical and chemical processes.

The luminescence phenomenon represents an extremely versatile and sensitive means whereby the physical behaviour of polymers may be examined at the molecular level. This review initially describes the ‘tools of the trade’ (the parameters which, in combination, confer high degrees of selectivity upon the technique) prior to discussion of their use. The account is illustrated by examples drawn mainly from the author's laboratory and includes applications of energy transfer, excimer formation and anisotropy experiments.

Recently, a lot of progress has been made in understanding the changes in physical behaviour of 2D self-assembled nanocrystals and the interactive phenomena due to their long-range organisation. As atoms arranged in a different manner in solids exhibit varying physical properties, physical differences can also be expected when nanocrystals are arranged in a disordered or in a highly ordered structure. For example, the first intrinsic magnetic behaviour in fcc ordered supra-crystals of Co nanoparticles has recently been reported [1,2].

Surrogates are widely used in the research and development of nuclear wasteforms, providing detailed insight into the chemical and physical behaviour of the wasteform whilst avoiding the widespread (restricted and costly) use of radiotoxic elements in the laboratory. However, caution must be exercised when dealing with surrogates since no single element or compound perfectly mimics all aspects of the behaviour of another. In this paper we present a broad discussion of the use of surrogates in waste immobilization, drawing upon and highlighting our research into glass and ceramic wasteforms for the immobilization of bulk PuO2.

We present a comparative analysis of structural changes in the surface areas of diffusion-stabilized polymers, and of the corresponding changes in their mechanical and physical behaviour. The study yielded original data on the influence of diffusion compositions on stability and other properties of polymers.