In addition to aesthetic conditions, sports footwear also meets a number of functional conditions (comfort, vibro-impact insulation, thermal-diffusion protection). The construction of certain types ...of sports footwear must withstand intense dynamic loads, so in the construction of sports footwear, priority is given to meeting the criteria of impact and vibration insulation. Modern techniques of injection molding of the bottom have enabled the realization of a number of new constructive solutions of the sole of the shoes.
The effect of UV irradiation and micro- and nano-TiO sub(2) as well as titanate nanotubes (TiNT) on the phase morphology and thermal properties of the electrospun PCL composite fibers was ...investigated. Polycaprolactone (PCL)/TiO sub(2) (micro- and nano-TiO sub(2) as well as titanate nanotubes) composite fibers were prepared by electrospinning a polymer solution. The PCL and PCL/TiO sub(2) composite fibers were exposed to UV light at irradiation times of 5 and 10 days. After UV irradiation the crystallinity of the electrospun PCL/TiNTcomposite fibers increased because of the large specific surface area of TiNT. The thermal stability of the PCL/TiNT electrospun composite fibers increased due to the formation of crosslinking structure after UV irradiation. The SEM analysis suggests that after UV radiation the fibers showed high degree of degradation due to the high number of fibers breakages and fibers surface voids. The results of FTIR spectroscopy confirmed that the TiO sub(2) particles enhance the degradation process because of their photocatalytic activity. J. Appl. Polym. Sci. 2016, 133, 43539.
Smartphone technologies have transformed the way people interact with each other around the world. The technology offers new approaches and opportunities for collecting, storing and sharing ...information. A novel smartphone technology application (app) originally developed for Patient Behavior Health applications was tested to determine if the proficiency of nursing students demonstrating a standardized seasonal influenza immunization protocol could be accurately recorded and subsequently evaluated remotely. The student performance was rated by four university instructors independently of each other. Each instructor used a standardized competency check-list to score these students. The study showed that by using the new smart-phone application, the remote evaluation of clinical nursing student proficiencies could be accomplished quickly and easily. However, the inter-rater agreement indicated that training of the evaluators in the use of the new app prior to scoring student performances will be needed. While the new smartphone application proved to be effective in documenting student performance, the technology promises to have practical uses in additional fields such as the secure monitoring of specialized training for paramedics, firefighters, police, skilled tradesmen, aircraft crews, etc.
Posljednjih desetljeća zanimanje znanstvenika diljem svijeta za tehniku elektroispredanja u stalnom je porastu. Razlog tome j mogućnost dovivanja jedinstvenih svojstva materijala načinjenih od ...nanovlakana međusobno isprepletenih u strukturu visoke poroznosti. Zbog velike specifične površine, velike poroznosti, povezanosti pora, mogućnosti kontrole morfologije vlakana te mogućnosti ispredanja raznovrsnih materijala, elektroispredeni materijali imaju široku primjenu u područjima: pohrane energije, senzora, filtracije, zaštitnog tekstila, katalizatora, bioinženjerstva tkiva, prijenosu i oslobađanju funkcionalnih komponenti i sl. Kompleksnost postupka očituje se u nizu faktora koji mogu utjecati na izgled vlakana kao i njihovu namjenu. U radu se daje pregled postupaka elektroispredanja, počevši od načela procesa i prednosti, kratkoj povijesti, detalja o čimbenicima u procesu elektroispredanja, uz opise nekih značajnijih područja potencijalne primjene elektroispredenih materijala.
To determine the causes and history of atherosclerosis it is necessary to understand the hemodynamic parameters of blood circulation. Hemodynamic parameters play an important role in the formation of ...atherosclerotic plaques, especially near bends and bifurcations where the flow separates from the wall. Here the flow is laminar and non-axial with eddies, secondary flow, flow separation and stagnation points. Stenoses are found predominantly in flow separation areas. Therefore, it is important to separately study the following flow parameters: steady and pulsatile flow, wall elasticity and non-Newtonian flow behavior of blood. A simplified silicon elastic y-model simulating the human carotid artery was used for the analysis of these parameters. This model can be used for numerical studies as well. Flow was visualized at steady flow using dyes and at pulsatile flow with a photoelastic apparatus and a birefringent solution. The local axial velocity at steady and pulsatile flow was determined with a one-component Laser-Doppler-Anemometer (LDA). Pulsatile flow was generated by a piston membrane pump. A glycerin-water solution was used to simulate the Newtonian flow behavior of blood. A DMSO-Separan water solution was used to simulate the non-Newtonian flow behavior. Pulsatile flow creates higher and lower shear rates so called oscillating shear rate compare to steady flow depending on the velocity amplitude. The non-Newtonian fluid showed a markedly different flow behavior than the Newtonian fluid especially in areas of flow separation. Shear gradients were calculated from these velocity measurements using a bicubic spline interpolation. Shear stresses were calculated from these velocity shear gradients and the viscosity of the non-Newtonian fluid at these shear gradients. At special areas, high shear stresses > 10 Pa were found. The elasticity of the model wall also influences the flow behavior. The measurements showed that the characteristics of pulsatile flow and the elasticity of the model wall should be observed concomitantly. This paper presents the steady and pulsatile flow with a Newtonian and non-Newtonian fluid in an elastic model.
SAŽETAK: Radnik provodi mnogo vremena za računalom obavljajući svoje radne zadatke. Sjedenje zahtijeva stalno mijenjanje položaja da bi se udovoljilo potrebama raznih aktivnosti koje radnik treba ...obaviti. Sjedeći položaj primjeren radu s računalom i pokretljivost tijela ograničeni su na kinematske sustave ruku, glave i djelomično trupa. Optimalnom vezom ljudskog tijela i računalnog radnog mjesta utječe se na pravilan radni položaj. Pri tomu se zamor i tjelesna energijska potrošnja svode na minimum. Pri radu s računalom potreban je visoki stupanj vizualne kontrole i time je potrebno koristiti vidne zone pri udobnom prenošenju pogleda i rotacije očiju. Istraživanja pokazuju da na radni učinak, osim funkcionalnosti i sigurnosti, znatan učinak imaju udobnost i zadovoljstvo radnika. Aktivnosti i položaji tijela mogu prirodno slijediti mentalnu i intelektualnu aktivnost, što uvelike pridonosi produktivnosti i zadovoljstvu radnika.
The paper investigates an experimental analysis of crack extension in steel DIN 42CrMo4V. This improved material has a high strength and toughness. It is used for statically and dynamically stressed ...components, in particular for larger cross-sections under high stress. The aim of the paper is to find possibility for more accurate and precise experimental determination of crack characteristics in three-dimensional problems of fracture mechanics. Notched test specimens with an initiated defect as a crack were made to determine impact properties and parameters of fracture mechanics. These investigations allow establishing the dependence of geometry of the movable crack and conditions of stress for its further extension. Therefore, it is possible to determine the characteristic quantity describing material behaviour, both in linearly elastic and in elasto-plastic fracture mechanics.
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