Surface topography

Engine downsizing is desired for modern heavy-duty vehicles to enhance fuel economy and reduce emissions. However, the smaller engines usually cannot overcome the parasitic loads during engine start-up. A new clutch system is designed to disconnect the downsized engine from the parasitic losses prior to the idling speed. A multi-scale, multi-physics model is developed to study the clutch system. Multi-body dynamics is used to study the combined translational-rotational motions of the clutch components. A micro-scale contact model is incorporated to represent the frictional characteristics of the sliding surfaces. Although the clutch is designed for dry contact operation, leakage of actuating hydraulic fluid can affect the interfacial frictional characteristics. These are integrated into the multi-body dynamic analysis through tribometric studies of partially wetted surfaces using fresh and shear-degraded lubricants. Multi-scale simulations include sensitivity analysis of key operating parameters, such as contact pressure. This multi-physics approach is not hitherto reported in the literature. The study shows the importance of adhesion in dry clutch engagement, enabling full torque capacity. The same is also noted for any leakage of significantly shear-degraded lubricant into the clutch interfaces. However, the ingression of fresh lubricant into the contact is found to reduce the clutch torque capacity.

nature materials | VOL 3 | JULY 2004 | www.nature.com/naturematerials 453 T win walls are planar defects that separate domains with uniform, but different, strain or electric polarization. They are observed in a broad class of materials, including ferroelectric, ferroelastic, co-elastic and superconducting crystals, which serve in a wide variety of mechanical, electrical and optical applications 1,2 . One unique characteristic of such crystals is that their physical properties as well as their macroscopic response to mechanical, electrical and optical loads are strongly related to their microstructural domain patterns 3,4 . These, in turn, are governed by the atomistic and mesoscale structure of twin walls and their interaction with other crystal defects. For example, it has been shown that as the dimensions of a ferroelectric thin film reduces to the submicrometre scale, the twin-wall thickness affects the dielectric, piezoelectric and optical properties of the film 5 . Moreover, as the dimensions further reduce to the nanometre scale, the twin-wall thickness dictates the transitions from a multidomain structure to single domain, and from a ferroelectric to a non-ferroelectric phase 6 .

The corrosion behaviour of Nd-Fe-B permanent magnetic alloys as well as of single phases of these alloys has been investigated in sulphuric acid at room temperature and humid air at 150°C using mass loss and electrochemical techniques. Scanning electron microscopy and scanning probe microscopy were used to study the surface topography. The electrostatic surface potential was examined by scanning probe microscopy using tapping mode. A correlation between the electrostatic surface potential and the corrosion rate of these alloys was found. The intergranular phases with higher electrostatic surface potential shows higher corrosion rate in both environments. The corrosion rate of the phases in the sintered permanent magnetic alloys increases as follows: f-phaseB h-phaseB n-phase. The differences in the chemical composition as well as in the preparation methods of these magnetic alloys have a distinct influence on the corrosion rates. Small additions of Co, Al and Ga increase the corrosion resistance of the magnetic Nd-Fe-B alloys.

The diagnostic study of spinal deformities has long been a focus of medical science. For a clear condition assessment of scoliotic patients X-ray images are used. Disadvantages of X-ray inspections, however, make methodological research, which can lead to fast and cost-efficient examinations without harmful radiation, reasonable. HISTORY: In 1874, after LORD RAYLEIGH had studied the resultant pattern, the so-called moiré fringes of two overlapping grids, he concluded that the phenomenon could be useful for measurement purposes. Beyond industrial applications further research, about a hundred years later, proposed moiré topography for measurement of the human body. AIMS AND METHODS: The aim of this publication, based on thorough study of resources, is to present the basic theory of the moiré method and its application in scoliosis. The two main methods − the shadow and projection moiré − of moiré technique are described in detail. Moreover, the paper presents KAMAL's algorithm suggesting to calculate the plane angle of curvature in single-curve scoliosis cases and proposes directions for further research and developments. RESULTS: The significant advantages of the moiré method are that it is fast, non-invasive, portable, cost-efficient and has no harmful radiation. A moiré technique chosen and algorithmized well can be convenient for substitution or as a complement of X-ray images in scoliosis. However, it is a limitation that a methodological standard which could lead to generally reliable results has not been created yet. Furthermore, the amount of labour required for the evaluation of moiré images is not inconsiderable. To achieve further success of the moiré method a dedicated partnership of engineers and physicians, respectively the application of technical-biomedical knowledge is needed.

Abstract: Purpose: To rationalize the use of surfactants by preparing Salbutamol sulphate microspheres using two types of surfactants, Tween 80 and Span 80 and study their effects on different characteristics of the microspheres. Methods: Microspheres containing Salbutamol sulphate was ...

The visual aspect of rough surfaces such as steel surfaces becomes of great importance for the quality of the final product they are dedicated to. In a previous work, we have solved the theoretically complex problem of automatically classifying surfaces according to the quality of their aspect. In this case, the measurements were based on topographical maps obtained through interferometric microscopy. The resulting data were analyzed by an algorithm based on morphological and statistical features extraction from surface topography, factorial analysis, bootstrap over-sampling and Bayesian classification. It was then important to apply this methodology as efficiently as possible to perform an automatic, on-line and continuous inspection of the product. In this paper, we focus on all steps leading to such an on-line application, among which choosing an optical sensor and the corresponding optical configuration adapted to an industrial environment and overcoming all difficulties to go from first laboratory tests to on-line measurements on fast moving product are particularly determining. Finally, results of on-line acquisitions are displayed, that are in good agreement with expected aspect characterization.

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We describe several examples where we use cross-correlation functions to quantify the similarity of 2D surface profiles or of 3D areal surface topography images. The applications have included (1) the manufacture of standard reference material (SRM) bullets and casings, (2) methods to assess whether bullets or casings have been fired by the same firearm, and (3) research to quantify similarities or differences between profiles of the same surface measured by different techniques or between a master surface and its replicas. The cross-correlation maximum is the functional parameter used to quantify similarity. A second parameter, called the relative profile (2D) difference or relative areal topography (3D) difference, may also be used to quantify differences and to recognize the ambiguous condition when two results have different vertical (z-) scales but identical shapes. Most of these examples have been applied in support of ballistics inspection methods in crime labs, but the methods are generally useful for estimating the accuracy of surface replication techniques or the ability of different surface topography instruments to measure the same surface and provide the same result. The instruments used in these studies were a stylus instrument and a Nipkow-disk type confocal microscope. Cross-correlation functions may also be used to assess differences resulting from the use of different filters to modify the same surface profile or topography image.

Although boiling process has been a major subject of research for several decades, its physics still remain unclear and require further investigation. This study aims at highlighting the effects of surface wettability on pool boiling heat transfer. Nanocoating techniques were used to vary the water contact angle from 20 to 110 • by modifying nanoscale surface topography and chemistry. The experimental results obtained disagree with the predictions of the classical models. A new approach of nucleation mechanism is established to clarify the nexus between the surface wettability and the nucleate boiling heat transfer. In this approach, we introduce the concept of macro-and micro-contact angles to explain the observed phenomenon.

This paper deals with the definition of a new finishing process named fluidized bed machining (FBM). Material is removed from the workpiece by an abrasive solid emulsion and air flowing through all the equipment, scratching the surface to be finished. This process is able to produce an accurate surface finishing both on areas inaccessible to traditional methods and complex passages. 9 10 11

X-ray fluorescence spectrometry is a common technique in determining the elemental composition of lithic materials. With the exception of glassy volcanic rocks like obsidian, most rock types are prepared for analysis by conversion of specimens to powder or glass in order to reduce the effects of irregular surface topography and internal inhomogeneity. Concern for artefact conservation necessitates a less destructive

An analytical model was developed to describe the mechanism of wetting dependence on surface nanotopography. This model relates the contact angle formation with the asperity geometry for application to a hydrophilic wafer surface, which is derived based on liquid-solid interfacial contact over the contact line. Experimental investigations were performed to verify the model. For much of the examined parameter room in the hydrophilic silicon wafer surface, it was found that the contact angle was strongly dependent on the ratio of asperity height to length, and the sharper asperity led to the higher contact angle. The observations are well consistent with Gibbs' contact-line theory.

Silicone elastomers exhibit a broad range of beneficial properties that are exploited in biomaterials. In some cases, however, problems can arise at silicone elastomer interfaces. With breast implants, for example, the fibrous capsule that forms at the silicone interface can undergo contracture, which can lead to the need for revision surgery. The relationship between surface topography and wound healing -which could impact on the degree of contracture -has not been examined in detail. To address this, we prepared silicone elastomer samples with rms surface roughnesses varying from 88 to 650 nm and examined the growth of 3T3 fibroblasts on these surfaces. The PicoGreen ® assay demonstrated that fibroblast growth decreased with increases in surface roughness. Relatively smooth (∼88 nm) PDMS samples had ca. twice as much fibroblast DNA per unit area than the 'bumpy' (∼378 nm) and very rough (∼604 and ∼650 nm) PDMS samples. While the PDMS sample with roughness of ∼650 nm had significantly fewer fibroblasts at 24 h than the TCP control, fibroblasts on the smooth silicone surprisingly reached confluence much more rapidly than on TCP, the gold standard for cell culture. Thus, increasing the surface roughness at the sub-micron scale could be a strategy worthy of consideration to help mitigate fibroblast growth and control fibrous capsule formation on silicone elastomer implants. (M.A.

The aim of this biomechanical study was to assess the interrelated effect of both surface roughness and surgical technique on the primary stability of dental implants. Material and methods: For the experiment, 160 screw-designed implants (Biocomp s), with either a machined or an etched surface topography, were inserted into polyurethane foam blocks (Sawbones s). As an equivalent of trabecular bone, a density of 0.48 g/cm 3 was chosen. To mimic the cortical layer, on top of these blocks short-fibre-filled epoxy sheets were attached with a thickness varying from 0 to 2.5 mm. The implant sites were prepared using either a press-fit or an undersized technique. To measure the primary stability of the implant, both the insertion and the removal torques were scored. Results: Independent of the surgical technique used, both implant types showed an increased insertion and removal torque values with increasing cortical thickness, although 42 mm cortical layer no further increase in insertion torque was observed. In the models with only trabecular bone (without cortical layer) and with a 1 mm cortical layer, both implant types showed a statistically higher insertion and removal torque values for undersized compared with the press-fit technique. In addition, etched implants showed a statistically higher insertion and removal torque mean values compared with machined implants. In the models with 2 and 2.5 mm cortical layers, with respect to the insertion torque values, no effect of either implantation technique or implant surface topography could be observed. Conclusion: The placement of etched implants in synthetic bone models using an undersized preparation technique resulted in enhanced primary implant stability. A correlation was found between the primary stability and the cortical thickness. However, at or above a cortical thickness of 2 mm, the effect of both an undersized surgical approach, as also the presence of a roughened (etched) implant surface, had no extra effect. Besides the mechanical aspects, the biological effect of undersized drilling, i.e. the bone response on the extra insertion torque forces should also be elucidated. Therefore, additional in vivo studies are needed.

Over the past decades, a number of different Synthetic Aperture Radar (SAR) techniques were developed for mapping the surface of the planets either from Earth or from orbiting spacecrafts. However, the idea to use radar to study the subsurface started to develop during the last 15 years. The ability of the radio waves to penetrate the ice, permafrost and arid surface was at the origins of the development of the Ground Penetrating Radars (GPR). GPRs have been widely applied on Earth with a large number of the scientific and industrial applications. The application of GPR to the space exploration relies on the same operation principle but requires the development of low power and low mass equipment. In this paper, we start by a short summary of the general electromagnetic behavior of the materials that determines the principal characteristics of ground penetrating instruments. Then we describe the GPR instrument that was developed for the Mars 1998 mission (unfortunately cancelled). Then, we discuss a general GPR design that can be implemented on future rover missions. The measurements from the surface cannot replace the global mapping from orbit using orbital radar sounders. MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) [1]and SHARAD (SHAllow subsurface RADar) [2] radars are examples of these orbital radar sounders that are now in Mars orbit on the Mars Express (ESA) spacecraft and MRO (NASA). The Lunar radar Sounder (LRS) on the Japanese Kaguya (Selene) mission (2008 -2010) was the radar sounder on the Moon [9]

Symbolic computation of NURBS plays an important role in many areas of NURBS-based geometric computation and design. However, any nontrivial symbolic computation, especially when rational B-splines are involved, would typically result in B-splines with high degrees. In this paper we develop degree reduction strategies for NURBS symbolic computation on curves. The specific topics we consider include zero curvatures and critical curvatures of plane curves, various ruled surfaces related to space curves, and point/curve bisectors and curve/curve bisectors.

This study evaluated the effect of three post surface treatments on quartz-fiber post (a) retention and (b) morphology. A control group was not treated. Different treatments were performed for the other posts: silanization; etching by hydrofluoric acid 9.5%; sandblasting with 50 m Al 2 O 3 . Two specimens of each group were submitted to a qualitative scanning electron microscopy (SEM) analysis. Remaining specimens were luted in prepared root canals (n ϭ 10) and retentions were determined using a universal testing machine. Retentive post bond strengths were significantly enhanced with any tested post surface pretreatment. The increase in retentive strength was more remarkable in sandblasted and etched posts. Significant changes of post surfaces were SEM observed after different conditioning treatments. (J Endod 2007;33: 264 -267)

Engine downsizing is desired for modern heavy-duty vehicles to enhance fuel economy and reduce emissions. However, the smaller engines usually cannot overcome the parasitic loads during engine start-up. A new clutch system is designed to disconnect the downsized engine from the parasitic losses prior to the idling speed. A multi-scale, multi-physics model is developed to study the clutch system. Multi-body dynamics is used to study the combined translational-rotational motions of the clutch components. A micro-scale contact model is incorporated to represent the frictional characteristics of the sliding surfaces. Although the clutch is designed for dry contact operation, leakage of actuating hydraulic fluid can affect the interfacial frictional characteristics. These are integrated into the multi-body dynamic analysis through tri-bometric studies of partially wetted surfaces using fresh and shear-degraded lubricants. Multi-scale simulations include sensitivity analysis of key operating parameters, such as contact pressure. This multi-physics approach is not hitherto reported in the literature. The study shows the importance of adhesion in dry clutch engagement, enabling full torque capacity. The same is also noted for any leakage of significantly shear-degraded lubricant into the clutch interfaces. However, the ingression of fresh lubricant into the contact is found to reduce the clutch torque capacity.

A series of novel low-bandgap triphenylaminebased conjugated polymers (PCAZCN, PPTZCN, and PDTPCN) consisting of different electron-rich donor main chains (N-alkyl-2,7-carbazole, phenothiazine, and cyclopentadithinopyrol, respectively) as well as cyano-and dicyano-vinyl electronacceptor pendants were synthesized and developed for polymer solar cell applications. The polymers covered broad absorption spectra of 400-800 nm with narrow optical bandgaps ranging 1.66-1.72 eV. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of the polymers measured by cyclic voltammetry were found in the range of À5.12 to À5.32 V and À3.45 to À3.55 eV, respectively. Under 100 mW/cm 2 of AM 1.5 white-light illumination, bulk heterojunction photovoltaic devices composing of an active layer of electron-donor polymers (PCAZCN, PPTZCN, and PDTPCN) blended with electron-acceptor [6,6]-phenyl-C 61 -butyric acid methyl ester or [6,6]-phenyl-C 71 -butyric acid methyl ester (PC 71 BM) in different weight ratios were investigated. The photovoltaic device containing donor PCAZCN and acceptor PC 71 BM in 1:2 weight ratio showed the highest power conversion efficiency of 1.28%, with V oc ¼ 0.81 V, J sc ¼ 4.93 mA/cm 2 , and fill factor ¼ 32.1%. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5812-5823, 2010

Determination of dry pressure drops is often the preliminary diagnostic tool for characterizing structured packing-containing columns. One conventional approach that ushered in this area evolves around the use of Ergun expressions along with mandatory experimental pressure drops for the fitting of some empirical constants characterizing a given packing. This method is strictly representational, and incapable of predicting the impact on

In this paper, vertical scanning interferometry (VSI) and atomic force microscopy (AFM) were used to characterize the topography of several nanofiltration and reverse osmosis membrane surfaces. Comparing roughness results from the two different characterization techniques revealed unique results for the various membrane surfaces. Roughness values tended to be higher from the interferometry measurements compared to those from AFM measurements for the same membranes. This was attributed to the inability of the AFM to capture dramatic changes in surface height of several microns or more. Based on interferometric measurements surface roughness was also found to increase with increasing scan-size up to a scan-size of 250,000 m 2 after which it remained relatively constant. Because such large scan-sizes are too large to be captured through AFM measurements interferometry appears to provide a more comprehensive characterization of membrane surface roughness.

Vanadium oxide thin film has been deposited on glass substrate at room temperature using pulsed laser deposition with the laser fluence of 1.4 J/cm 2 under high vacuum. X-ray photoelectron spectroscopy analysis shows that the film is oxygen deficient compared to the stoichiometric V 2 O 5 . X-ray diffraction study reveals the amorphous nature of the film. Atomic force microscopy ensures the particulate free film with smooth surface topography. From the temperaturedependent resistance measurements, thermistor parameters such as temperature coefficient of resistance (a) and thermistor constant (B) were determined as 28000 ppm K À1 and 2623 K, respectively.

Three-dimensional surface roughness of mating parts of engineering assemblies has a significant influence on their functional behaviour. Studies on load bearing capacity in elastohydrodynamic contacts, gap flow analysis in precision hydraulic assemblies using modeled 3D fluid continuum micro gap geometry, etc., have made it possible to quantify the effect of certain 3D surface roughness parameters on frictional behaviour of the assemblies. This set forth the need for artificially generated three-dimensional engineering surfaces having prescribed roughness values for a better understanding and prediction of tribological problems. In this paper, an algorithm is developed for the numerical generation of three-dimensional anisotropic surfaces with prescribed 3D surface roughness parameters. The procedures employ either the Non-linear Conjugate Gradient Method (NCGM) or 2-D Digital Filter method. The results show that both the methods can adequately produce surfaces at small correlation distances, while at higher correlation distances the NCGM yields better results. Comparison between model-simulated output and measurement results of three-dimensional surface roughness of engineering surface show a good match, supporting the validity of the model.

Although surface finish can be a critical variable in clinical performance, there is a dearth of information regarding surface characteristics of teeth prepared for artificial crowns. This study characterized teeth prepared for complete cast restorations using three representative types of rotary instruments. One hundred and five standardized tooth preparations for complete crowns were performed using a modified milling machine on extracted human teech with diamond, tungsten carbide, and tungsten carbide finishing burs of similar shape (n = 35). The prepared dentin was analyzed with a surface profilometer and a scanning electron microscope (SEM). Differences between rotary instrument groups were determined with parametric ANOVA and Tukey's Studentized Range (HSD). Statistically significant differences in the surface topography of prepared teeth were seen. Mean surface roughnesses (Ra) were 8.6 and 6.8 μm for teeth prepared with diamond and tungsten carbide burs. Teeth completed with finishing burs appeared to result in a smoother surface (1.2 μm).

The rapid and automated detection of manufacturing flaws is becoming increasingly important in order to maintain competitive advantage in many production environments. In the case of natural and ornamental materials, the presence of both surface colouration and surface topography is often such that manual inspection, along with many conventional imaging techniques, fails to isolate physical or structural defects in the presence of complex and random patterns. In this paper the concepts of photometric stereo are adapted and extended for application in manufacturing environments. A case study on the high speed inspection of ceramic tiles is presented for the analysis of surfaces at production line rates of up to 30 m/min. This new technique, for the first time, demonstrates a genuine and commercially attractive potential for the practical automated quality control of complex surfaces. A commercial system, based on this research, is currently being developed. # 2005 Published by Elsevier B.V.

Short henequén fibers were modified with a silane coupling agent in order to find out its deposition mechanism on the fiber surface and the influence of this chemical treatment on the mechanical properties of the composite. It was shown that the partial removal of lignin and other alkali soluble compounds from the fiber surface increases the adsorption of the silane coupling agent whereas the formation of polysiloxanes inhibits this process. The existence of a chemical bond between the coupling agent and the henequén fiber was confirmed by XPS and FTIR spectroscopy. It was further verified that the interaction between the fiber and the matrix is much stronger when the fiber surface topography is combined with the chemical modification of the fiber surface with a silane coupling agent. ᭧

In order to study the behavior of the early stage of pitting corrosion, an image analysis based on discrete wavelet packet transform and fractals was used. Image feature parameters were extracted and analyzed to characterize the pitting corrosion development with test time. It was found that the feature parameters: Shannon entropy, energy, fractal dimension and intercept increased with the test time. Therefore the image processing techniques were promising and effective tools to analyze and detect the pitting corrosion.

Introducing specific textures on a tribological surface can contribute to friction reduction in sliding contacts. In the present paper, a pulsed Nd:YAG laser emitting at 1064 nm, was used against 100Cr6 steel samples in order to produce well-defined surface micro-pores, which can act as lubricant reservoirs, micro-hydrodynamic bearings as well as traps for wear debris. Due to the high flexibility of the laser system, structural features such as shape, size, density and depth can be varied easily by changing the laser parameters. To optimize the parameters of the laser surface texturing process, an investigation was performed using different pulse numbers, various pulse energies and two different modes (single-and multi-mode). The microtextures were characterized with optical microscopy, scanning electron microscopy (SEM) and by topography techniques. The relationship between the laser processing parameters and qualitative and quantitative profile of the micro-pores was studied. Tribological testing of laser textured surfaces was performed in a low frequency-long displacement reciprocating sliding wear tester under boundary lubrication and results compared to un-textured case. Tribological comparison of textured, textured and lapped, and untextured surfaces shows only minimal influence of texturing for contact conditions investigated.

Microelectromechanical systems (MEMS) represents a technology that integrates miniaturized mechanical and electromechanical components (i.e., sensors and actuators) that are made using microfabrication techniques. MEMS devices have become an essential component in a wide range of applications, ranging from medical and military to consumer electronics. As MEMS technology is implemented in a growing range of areas, the reliability of MEMS devices is a concern. Understanding the failure mechanisms is a prerequisite for quantifying and improving the reliability of MEMS devices. This paper reviews the common failure mechanisms in MEMS, including mechanical fracture, fatigue, creep, stiction, wear, electrical short and open, contamination, their effects on devices' performance, inspection techniques, and approaches to mitigate those failures through structure optimization and material selection. Novel technologies developed by him, to fabricate 5-10-μm-pitch nano nickel-tin flip-chip interconnects, shape-memory organic capacitors, and nanoelectrode systems inside microtube, have found applications in biosensors, MEMS, microelectronics fabrication, and packaging technologies.

This paper introduces a new filtering technique that aims to improve the quality of measured surface data by removing measurement artefacts, such as spikes and batwings, that impact the data analysis. The methods currently available for measuring surfaces allow a large number of heights on a surface to be measured with high lateral and vertical resolution. However, measured data often contain outliers, which take the form of sharp peaks on the surface (Dirac type) and are particularly common in optical measuring methods. By nature, these peaks cannot belong to a 'real' surface; thus, an outlier filtering step is necessary and should be the initial preparation step for the measured data prior to any further analysis. The measurement artefacts can strongly influence the topographic characterization parameters and adversely influence quality control efforts as well as functional analyses for discrimination and correlation of the surfaces. The proposed method makes the filtering of such outliers easier and more effective with criteria linked to the standard deviation (Peirce method) and associated with a modal form-filtering method that is independent of the presence of these peaks. The filter is then applied to the surface at different scales; thus, the method is scale sensitive and improves the filter efficiency. This new method is applied to surface data that were measured by optical means from different surfaces. The surfaces were measured with a 3D-measuring laser microscope and laser scanning confocal microscopy. The results of testing these examples will determine the extent to which this method can improve the quality of measured data and thus influence the results of further analyses.

This paper reviews contact modeling with an emphasis on the forces of contact and their relationship to the geometrical, material and mechanical properties of the contacting bodies. Single asperity contact models are treated first. These models include simple Hertz contacts for spheres, cylinders, and ellipsoids. Further generalizations include the effects of friction, plasticity, adhesion, and higher-order terms which describe the local surface topography. Contact with a rough surface is generally represented by a multiasperity contact model. Included is the well-known Greenwood-Williamson contact model, as well as a myriad of other models, many of which represent various modifications of the basic theory. Also presented in this review is a description of wavy surface contact models, with and without the effects of friction. These models inherently account for the coupling between each of the contacting areas. A brief review of experimental investigations is also included. Finally some recent work, which addresses the dynamics and associated instabilities of sliding contact, is presented and the implications discussed.

While there has been significant progress in the treatment of ischemic heart failure, it remains a significant health and economic problem worldwide. In this paper, we present the challenges of modelling ischemic heart failure and introduce a user-friendly software system that will be a sub-set of the Virtual Pathological Heart environment which is currently being developed under the FP7 VPH2

This review reports recent advances in the field of the blends of natural and synthetic polymers as new biomaterials. These materials have attracted both academic, and, for several blends, industrial attention because they exhibit improvements in properties required in the biomedical field. Herein, the structure, preparation and properties of the blends of natural and man-made polymer are discussed in general, and detailed examples are also drawn from scientific literature and practical work. The most common natural polymers: collagen, chitosan, elastin, keratin and silk are discussed as a components of blends with man-made polymers.