Advanced Materials Research Vols. 47-50

Abstract: In order to measure 3D displacement components and surface strain distributions of objects, three systems for digital holographic interferometry were developed. In this study, these three systems are introduced and the applications to measurement of 3D displacement components and surface strain distributions of cantilevers are shown.

Abstract: In 1974 an unusual phenomenon called Usherenko effect was observed in impact experiments [1,2]. Surprisingly large were impact produced craters whose depth varied between 100 and 10000 times the impactor’s size. For materials whose static strength is small or zero, e.g., sand or water, the depth of penetration is no larger than 100 times the size. When a macro-size body impacts on a barrier, it produces a crater whose depth is normally in a ratio of no larger than 6-10 to the body’s size regardless impact parameters. The papers [1,3] give overviews of models which were developed to explain the phenomenon. They all try to answer why material resistance to the penetration of micro-size impactors suddenly decreases. We suggest a model that uses the concept of particle entrainment by a shock produced by the impact of a bunch of particles on a barrier. The approach was proposed by V.A. Simonenko [4]. It is based on calculations by the finite-difference technique TWS [5,6]. Such an approach shows prospects for further development with account for new experimental results obtained after 1991. The goal of this paper is to demonstrate feasibility of applying this approach for justification of impactor’s acceleration in solid.

Abstract: It was shown experimentally that super-deep penetration (SDP) effect occurs due to collision of a microparticles clot with a metallic thick-walled shell. It has been established that this process is accompanied by plasma microjets ejection from an internal surface of a protective shell. Plasma microjets are highly injurious in relation to elements (microcircuits) of electronic control systems.

Abstract: Polymer-reinforced polymer composites have been successfully created from blends of engineering and commodity plastics. These microfibril reinforced composites (MFCs) contain molecularly oriented in-situ fibrils, evenly dispersed throughout a homogeneous matrix. MFCs have several potential applications in a range of areas including food packaging materials and biomedical scaffolds. This paper provides an overview of the characterisation of several MFCs derived from polyethylene/poly(ethylene terephthalate) (PE/PET) blends. It investigates the tensile properties of MFCs with different microfibril orientations as a result of various consolidation techniques. It also describes a study on the oxygen permeability of moulded MFC films and evidence of biological cell growth on microfibrillar polymer structures.

Abstract: Fiber reinforced polymer (FRP) composites are becoming more frequently used in civil engineering structures because of their superiors advantages. While in practice, partial deterioration of concrete columns occurs occasionally, frost damage, aging or construction quality might lead to concrete deterioration. However, confined the whole columns including intact and deteriorated parts has been regarded as a waste. Few literatures have involved in partial confinement only to defect parts. The objective of this paper is to present an effective method to deal with the partial deteriorated strength columns, and to gain insight into the mechanical behavior of the defect part. Five groups of plain square columns are cast, different layers of CFRP sheets have been wrapped just on the deteriorated part to investigate the improvement with CFRP sheets and to verify the practicability of partial confinement. Columns are subjected to monotonic axial compression until failure occurs. Axial load, axial and transverse strains are measured to compare the different behaviors and to evaluate confinement level supplied by CFRP sheets. Experimental results show that partial confinement with CFRP can significantly enhance the strength and the ductility of the deteriorated strength part, then, the load capacity of the entire column can be improved subsequently.

Abstract: Main purpose of this paper is to describe the method for preparation of the reactive nanocellulose biocarrier and to discuss some its biomedical and cosmetic applications. The method for preparation of the biocarrier was proposed that includes steps of controlled depolymerization of initial cellulose; structural and chemical modification in order to graft various biologically active substances to cellulose particles and high-power mechanical disintegration of the modified cellulose particles in liquid media. As a result, the dispersion of the bioactive nano-cellulose was obtained. Due to nano-size, particles of bioactive nano-cellulose capable clean skin's pores, open them and penetrate through the lipid layer and epidermis within the skin strata. This effect of the biocarrier can be employed at the development of advanced types of biomedical and cosmetics remedies used for gentle care and effective treatment of the skin.

Abstract: Magnesium has been proposed as an implant metal due to its low weight and inherent biocompatibility. However, it use as a biomaterial is seriously limited by its poor corrosion n resistance. Die-cast AZ91D and rolled AZ31B alloys, which are commercial magnesium alloys, were used in this study. After plasma anodization, SEM showed that the surface had a relatively high porosity with some micro-cracks. EDX revealed Mg, Al and Zn on the surface of the samples before anodization. After anodization , there was an increase in the oxygen EDX peak intensity with a concomitant decrease in the magnesium intensity . Anodized AZ91D had the best corrosion resistance according to the potentiodynamic polarization curves. After immersion in Hanks solution for 10 days, the untreated AZ31B sample had the highest pH value due to formation of OH- on the film surface.

Abstract: Hyperthermia using ferrofluid with alternating current (AC) magnetic field, which is the principal method we try to use in this study, where chitosan was used as a surfactant agent. Irradiation of Co-60 plays multi-function roles on the syntheses of chitosan-coated nanoparticles. Optimal conditions for synthesizing magnetic nanoparticles have been successfully found by the Taguchi method in which the dominated quality characteristic was SAR.