Wool as important row material in textile processing is the oldest fibre used by people to make fabrics. In order to make products corresponding to market requirements, use of the increasingly fine wool fibres has expanded. This type of fibre is mainly imported. In order to establish optimal conditions for the experiment was chosen a central compose rotatable program, second order, with two independent variables: partial draft and spindles speed at spinning machine. Using data obtained with the program have established the optimum parameters of the spinning process. The paper examines the optimization of the spinning process of a yarn made by 100% wool, sort 70’s Nm 52.
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The lack of drug specificity for inner ear structures and the side effects of systemic administration have determined the treatment strategies to evolve from systemic administration to local application of drugs. The disadvantages of systemic or local administration of drugs for the inner ear, have led to the development of nanoparticles with specific activity. The study presents current research advances regarding the use of nanoparticles (liposomes, PLGA, dendrimers, silica or magnetic nanoparticles, etc.) in inner ear pathology treatment.
One important direction for the mechanical behavior study of the materials is the fracture surface evaluation. This work makes a qualitative interpretation of the fracture surface from some Zircaloy-4 SEM microfractographies by using the fractal analysis technique. By reason of the current research, we introduce for the first time some new algorithms, most of them based on Box Counting methods and variations for 2D and 3D structures. The Box Counting algorithm is an efficient algorithm to compute the Fractal Dimension and can be applied directly on gray-levels images.
In accordance with ISO 4049/2000 Standard, the alleged radioopaque restorative materials must have a radioopacity value similar or higher with an aluminum layer of the same thickness. Depth polymerization of RDC represents half the depth of hardening under experimental conditions. European Standard requires a minimum of 0.5 mm for opaque diacrylic cements, 1 mm for opaque shades of restorative materials, respectively 1.5 mm for the other materials [11]. The aim of this study is to measure the radioopacity of different nanocomposite materials and coordinate this with the material’s performance.
The aim of our scanning electron microscopic study was to evaluate the cleaning efficiency of irrigating solutions used in endodontic treatment regarding smear layer removal from the root canal dentin walls. Ethylenediaminotetraacetic acid (EDTA)17%, citric acid(CA)10% and chlorohexidinegluconate (CHX)2% solutions were tested as final irrigants after endodontic treatment. The study was conducted on extracted teeth, divided in four groups according to the irrigation protocol used. The specimens were analyzed by scanning electron microscopy and the amount of smear layer present at apical, middle and coronal level was recorded, based on a scoring system. Data were statistically analyzed using Kruskal-Wallis and Friedman test and the level of significance was set at p[0.05. At the coronal and middle thirds we recorded no statistically significant difference between EDTA and CA regarding the smear layer removing capacity. Final irrigation with 10% CA proved to be more efficient than 17% EDTA in smear layer removal at apical level of the root canal, with p[0.05 (p=0.036), which is an important area for disinfection in endodontic treatment.
HY zeolite (solid acid) doped poly (aniline) has been synthesized through oxidative polymerization of aniline with ammouim peroxydisulfate used as an oxidant in aqueous medium. The influence of HY zeolite contents (5wt %, 10 wt %, 15wt %, 20wt % and 50 wt %) on the conductivity characteristic, thermal stability, and specific surface area of poly (aniline)/ HY zeolite composites was performed. All samples were characterized by FTIR, UV-Vis, XRD, TGA and SEM techniques. The electrical conductivity was measured using a four-probe method and it was found to be equal to 2.2 S/cm. FTIR spectra has confirmed the presence of poly (aniline) in the form of conducting emeraldine salt and suggest significant interaction of poly(aniline) with HY zeolite.
The use of Additive Manufacturing methods in the manufacture of custom implants and the development of new biocompatible materials that can be processed by Selective Laser Sintering Technology, represent a trend in biomechanics. In this study two types of biomaterials were analysed and tested – PA 2200, the most used material for cranioplasty, obtained at different laser powers and polymethyl-methacrylate (PMMA). In order to analyse the mechanical behavior of the evaluated materials, the mechanical tests were made for tension, flexure and compression. It was found that the values for PA 2200 material are within the limits of the mechanical characteristics required for cranioplasty implants.
The success of an endodontic material depends on its sealing ability, as most post-treatment endodontic disease usually occur due to marginal leakage in the apical area of the root canal. The aim of our study is to evaluate the sealing ability of a Mineral Trioxide Aggregate-based endodontic sealer (ProRootMTA), compared to other frequently used materials, on extracted human teeth, using a dye penetration leakage test. The results showed a significant difference (p[0.01) between ProRoot MTA and the other two sealers.
The paper presents a method for elaboration and characterization some chitosan-gelatine membranes with different collagen-gelatine mass ratio, cross-linked with glutaraldehyde (GA) and coupled with extract plants. The aqueous extracts obtained from these plants were analyzed in terms of biologically active substances content (amino acids, polyphenols and phytosterols). The investigation for all obtained membranes involves: SEM microscopy, porosity, degradation test, contact angles measurement, hemolisys and antibacterian index determination.
This paper analyses the influence of carbon filler content over the mechanical properties of vinyl ester nanocomposite. The carbon fillers used in this study were graphite and graphene nano sized particles in the following weight percentage: 0.10, 0.15 and 0.20. The mechanical properties such as modulus of elasticity, flexural stress and flexural strain were determined using three point bending tests.A significant enhancement of overall mechanical properties were achieved for some of the nanocomposite materials studied.