Nanotechnology and nanomaterials have become the "in" topics among researchers in the last few decades. The reason for nanotechnology's attractiveness is in the new opportunities that the technology ...offers. The paper gives a short overview of the emergence of nanotechnology, its basic terminology with focus on the types of nanomaterials, their unique properties and possibilities of application. The benefits of this booming field are evident in many areas including information and communication technology, energy storage, environmental engineering, chemical industry, food industry, medicine, pharmaceutical industry and cosmetics. On the other hand, the unique properties of nanomaterials which make them so attractive are also the cause of major concerns because of their potential harmfulness to human health and the environment. Nanomaterials easily enter the environment during production processes or in waste disposal, and affect the human body through occupational exposure and use of different products. Probably the biggest concerns of toxicologists at this point are the potentially harmful impacts of nanomaterials which are still insufficiently understood.
Međunarodna suradnja u nastavi i istraživanjima porasla je kao rezultat raširenosti i dostupnosti globalne mreže. Iako je primjena e-obrazovanja iznimno poraslo, uporaba daljinskih laboratorija u ...istraživanju i nastavi relativno je nova. Opisan je razvoj daljinskog ergonomijskog laboratorija pomoću internetske tehnologije. Svrha daljinskog laboratorija jest da se diljem svijeta omogući pristup naprednoj tehnologiji manekena na termalno napuhavanje koja nudi temelj za mjerenje termodinamičkih svojstava zaštitne odjeće tijekom izlaganja kontroliranim uvjetima okoline. Laboratorij je izazvao opće zanimanje te promiče međunarodnu suradnju na području nastave i istraživanja u ergonomiji.
In this work, a two dimensional (2D) finite element foot model was established from magnetic resonance imaging (MRI) of a male subject. The model comprises first medial planar cross-section through ...the foot, representing the foot in standing posture. For specified external load, the stress and strain distribution field under foot structure are determined. The material characterization of foot structure components are stronger related to diabetic phenomena. The new material model for soft tissue based on mixture theory is proposed. The linear finite element model replaced by nonlinear counterpart with segment-to-segment contact element.
Foot print patterns of the bound feet of a 90-year-old Chinese female were made to obtain insight into the ergonomic consequences of a Chinese custom that caused significant disabilities for many ...women throughout history. Pressure patterns were evaluated using the techniques applied to standard thumb print analsyis. A digital summary of the pressure patterns were compared to the patterns obtained from a normal subject. The outcomes indicated that the bound foot produced greater plantar tissue pressures than the non-bound foot. These observations help explain the discomfort, gait abnormalities, and disabilities exhibited by many older women with bound feet living in China today. Although foot-binding is no longer practiced, this study offers an ergonomic perspective on a custom practiced in China for centuries.
The cardiovascular disease is one of most frequent cause deaths in modern society. The objective of this work is analyse the effect of dynamic vascular geometry (curvature, torsion, bifurcation) and ...pulsatile blood nature on secondary flow, wall shear stress and platelet deposition. The problem was examined as multi-scale physical phenomena using perturbation analysis and numerical modelling. The secondary flow determined as influence pulsatile pressure, vascular tube time-dependent bending and torsion on the main axial flow. Bifurcation and branching phenomena are analysed experimentally through, blood-like fluid pulsatile flow across elastic rubber-like Y-model model. The problem complex geometry near branching in platelet deposit modelling is resolved numerically as Falker-Skan flow.
The cancellous bone effective properties relations are analysed on multiscale across two aspects; properties of representative volume element on micro scale and statistical measure of trabecular ...trajectory orientation on mesoscale. Anisotropy of the microstructure is described across fabric tensor measure with trajectory orientation tensor as bridging scale connection. The scatter measured data (elastic modulus, trajectory orientation, apparent density) from compression test are fitted by stochastic interpolation procedure. The engineering constants of the elasticity tensor are estimated by last square fitt procedure in multidimensional space by Nelder-Mead simplex. The multiaxial failure surface in strain space is constructed and interpolated by modified super-ellipsoid.
Natural polymer-based scaffolds are generally considered as favourable matrices for
the adhesion and growth of cells in tissue repair. One of the most popular materials in
this respect is silk ...fibroin, known for its wide usage in biomedical applications. This work focuses on the development of electrospun scaffolds based on poly(ε-caprolactone)
(PCL) and silk fibroin (SF) evaluated regarding the SF effect on their morphology, surface wetting ability, thermal properties, and HaCaT model cell line biocompatibility. The
study revealed that the lowest PCL/SF concentration resulted in highest bead-like morphology formation, relatively thick fibers with the presence of random beads in the case of PCL, while uniform and thinner fibers in the case of increasing PCL/SF content scaffolds. The addition of SF reduced the degree of crystallinity in the PCL due to the less
organized crystal structure, and decreased its thermal stability. Both SEM and MTT analyses showed cell presence on all scaffolds three days after cell seeding. Although SF
improved PCL hydrophilicity, as shown quantitatively by the MTT assay for improved
cytocompatibility properties, more structured electrospun PCL/SF scaffold strategies are
required.
This study focuses on the behavior of electrospun polyurethane fibers filled with nano, micro spheres and nanotube TiO
2
, thus nTiO
2
, mTiO
2
or TiNT, under real time ultraviolet (UV) radiation. ...Analyses were conducted using scanning electron microscopy (SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis and differential scanning calorimetry (DSC) techniques. Significant changes of thermoplastic polyurethane (TPU) + 0.5% nTiO
2
and TPU + 0.5% mTiO
2
fibers morphology, that is, agglomerated TiO
2
particles, were observed on material surfaces due to TPU fiber degradation, also supported by FTIR spectra given as reduction in the peaks intensities after UV radiation, especially in the case of TPU + 0.5% nTiO
2
. Further, after UV radiation, the initial degradation temperature reduction of the hard segment for all materials was up to 40℃. A significant reduction in the final degradation temperature (from 397.8℃ to 274.1℃) was noticed for the mTiO
2
filled fibers, suggesting their photocatalytic activity, while T
g
was increased up to 20℃ for almost all fillers added to TPU, thus indicating lower molecular chain mobility upon UV radiation.
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