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This study presents a novel strategy for the modulation of the stop band of a polymer photonic crystal by utilizing the pattern on the surface of a written DVD. Thus, fluorescent dye doped polymer colloids (305 nm) capable to self-assemble have been obtained through soap-free emulsion polymerization and deposited on the surface of the DVD, both the top and bottom. The resulting films were investigated by SEM, UV-Vis and fluorescence spectroscopy. Depending on the design of the surface, the modification of the band gap, as well as the emission properties of the photonic crystals were observed.

The study samples were taken Meliodent self-curing acrylic partial denture acrylics and flexible acrylate Bre.flex, used in manufacturing. The aim of the study was to observe if the irradiation of deployable dentures, there are changes in the structure of the material. Samples were subjected to irradiation at three different values of power (500, 650, and 750 W) and three different time intervals (2, 3, or 5 min), and was later examined by electron microscopy in comparison with control samples of the same material. After the microwave irradiation of materials it is made partial dentures and analysis using scanning electron microscope found no changes notable in the studied areas.

In this paper, some of the ionized forms and aggregated forms of tetrasulphonated porphyrin TPPS4, have been separated by passing it through a composite polymer membranes of polysulfone type with N-methyl-pyrolidone and magnetite. The aqueous solutions of TPPS4 at different pH values have been prepared, characterized and passed through the membrane, leading to the conclusion that the acidic or alkaline solutions have been transformed into neutral form with certain therapeutic properties in photodynamic therapy.

This paper is a brief characterization of composite materials and experimental system used for the measurement of heat transfer in a multilayer Board with the help of thermocouples. Also determine the temperatures, thermal gradients, thermal flows, in stationary mode, within a range of 570 s for a plate of composite materials (aluminium foil, expanded polystyrene, extruded polystyrene, universal adhesive).

Vocal rehabilitation in patients with total laryngectomy can be done by using a phonatory prosthesis. The functioning principle of a speaking prosthesis is based on the existence of one-way valve from the trachea to the esophagus that allows the exhaled air to enter the residual pharynx and produce the voice. One of the possible complications that can occur during this process is represented by the aspiration of the prosthesis into the trachea. The aim of this paper is to present the design of a safety device, made of polydimethylsiloxane, which should prevent the tracheal aspiration of the phonatory prosthesis during primary or secondary insertion or during the replacement procedures.

Drug delivery systems are used to protect unstable pharmaceutical active substances, to modify the characteristics of the loaded drug or to deliver the active ingredient to its specific receptor. In this study, polyurethane-based particles were obtained and the influence of stirring speed during the synthesis, the drying speed of products as well as the chain extender/polyol ratio were determined in order to describe the characteristics of the new particles. The final particles were elongated in shape and stable up to 280oC. We established that the drying speed did not influence in a noticeable manner the particles size and led to the formation of a dispersed system in which the constituents presented a high tendency to form clusters or conglomerates. The results suggested that the stirring speed during the synthesis and the chain extender/polyol ratio may be used as two important parameters which can influence the particles sizes without affecting other characteristics. In vivo evaluation on mice skin model did not reveal any damaging properties of the newly synthesized particles.

The high content of organic matter of surface waters represents a real danger for aquatic fauna, even if their toxicity is low. Such a high rate of biodegradation leads to oxygen depletion of the waters in question and thus the suffocation of aquatic fauna. The elimination of these disadvantages by using purge technologies of catalytic oxidation may be a viable solution. The oxidation process of pollutants in wastewater that contain glycerol or molasses was performed on nanostructured catalysts based on Fe, Mn and Fe-Mn mixed. The catalysts were prepared by precipitation-coprecipitation of selected precursors and they were characterized by determination of particle size distribution. Measurements for the determination of particle size distribution were carried out using the method of dynamic light scattering. The oxidation process was conducted in a batch reactor equipped with air bubbling system, in suspension of catalysts. Efficiency of oxidation process of wastewater loaded with glycerol or molasses is expressed by biochemical oxygen demand. Compared to Mn or Fe catalyst, the Fe-Mn catalyst favors an advanced treatment of wastewater that contain glycerol or molasses by oxidation with air.

Adhesive cements (that chemically adhere to both the tooth and the restoration material) are considered to be a highly specialised group of composite cements. They involve a three-step procedure (acid etching, bonding agents or silane and composite resin), like cements using acid etching technique and have similar physical properties as the latest. The purpose of this study was to statistically analyse the values of the adhesive bond between dental tissue and ceramic, using three types of cements (both commercial products and a product from Romania) and one type of ceramic. The separate combinations were studied in order to identify the weakest link of the interface of dental-tissue-ceramic in terms of shear bond strength. The adhesion values recorded at the interface of cement-enamel for Dualcim and Nexus cements were significantly different from those recorded for Variolink cement. The highest resistance to adhesion was recorded to the interface cement Variolink – dentin, the average being 16.19 MPa.

This paper presents a model for the numerical simulation of Charpy test, using together Smoothed Particle Hydrodynamics (SPH) Method and Finite Element Method. Numerical simulation of the mechanical tests require the use of special material models, so the material fracture to be also simulated. The new numerical method, SPH Method, in fact a version of the Free Particle Method, presents some important advantages among which no material failure criterion to be used. Our proposed model is a model combining the FEM and SPH Model: only the specimen is modeled only by particles. The numerical results are compared with the results using only FEM and finally with the experimental data. Avoiding the material models, in fact the failure criterion, by SPH method presents a great advantages because any material model (Plastic-kinematic, Johnson-Cook, Modified Johnson-Cook, Picewise linear plasticity etc.) involves knowledge about some material constants. This aspect is very important and in the same time, very difficult. The numerical model together with some theoretical fundamentals of the SPH Method could be more then an invitation for using the SPH Method, it could be an available model able to inspire the researchers in their work. The paper is finished after some conclusions.

PETG (polyethylene terephthalate) is a very popular plastic material when it comes to manufacturing invisible orthodontic appliances. These devices are very common nowadays because they provide an esthetic treatment alternative to braces. This type of plastic material has several indications in orthodontics: manufacturing night guards, positioners, orthodontic aligners, invisible single-layer/multi-layer thermoplastic retainers, bite splints, space maintainers, mini trays, fluoride trays, growth guiding splints, etc. The polyethylene foils provide resistant wear and rigid devices, with no substantial elastic deformation, capable of assuring a reliable orthodontic treatment.