Volume 52, Issue 4

Abstract: The low biodegradability of petroleum-based plastic materials led to the search for novel biodegradable plastics. In this way, a team of German researchers developed, produced and marketed a material that can help the environment, in terms of 100% biodegradability and renewability, contributing to a more efficient use of resources. The trade name proposed by the team is “liquid wood” and is a high-quality thermoplastic material. It brings together the wood and plastics processing industries, in order to make products with complex design geometry and to process warm material wood (lignin and natural fibers) using the same technique and equipments just like for conventional thermoplastic materials. This paper presents analyses of bending test behavior in case of Arboform L, V3 Nature -“liquid wood” (A-LW) and Arboform reinforced with Aramid Fibers (A-LWAF). The results were compared with technical literature and some plastic materials in case of requirement for greater stiffness of material. Keywords: bending test, Arboform, bending strength, flexural modulus

Abstract: Metallic iron nanoparticles were synthesized by the hydrazine reduction method in three experimental versions. The average size and particle size distribution obtained by the three versions was determined with a particle size measurement system making use of dynamic light scattering. The presence of the aromatic solvent and anti-caking additive influences the average size and size distribution of the particles. The metallic iron nanoparticles obtained in the three experiments were used in the treatment of waters containing a 6.8 mg/l concentration of hexavalent chromium. Reduction of hexavalent chromium concentrations as well as total chromium, COD and TSS depend on pH and reaction times. Thus, the optimal conditions requires for Cr6+reduction, for obtaining values lower than 0.1 mg/l, are: the pH value of 11, a duration of the process 10 hours. Keywords: nanoparticles, chromium, wastewater, chemical oxygen demand, biochemical oxygen demand

Abstract: The paper deals with the synthesis of compounds based on standard epoxy resin/ modified epoxy resin with different molar ratios of glycols and with the characterization of cured products to investigate the influence of the addition of various amounts of modified resin on the compound flexibility as compared to standard epoxy resin. Modification of epoxy resins with glycols results in a wide range of specific properties superior to neat epoxy resin. These properties are highlighted by characterizing the products obtained using various types of glycols and different standard resin/ modified resin weight ratios by physical- mechanical analyses and Dynamic Mechanical Analyses (DMA). Keywords: glycol-modified epoxy resins, glass transition, dynamical properties and mechanical properties

Abstract: This research is based on the study of the chemical polymerization of nanocomposites based conductors polypyrrole PPy(Cl) and the HY Zeolite type Faujasite as reinforcements, at room temperature and atmospheric pressure using FeCl3 as initiator of the reaction and dopant at the same time. After characterization commodity we methods primarily on the polymerization of pyrrole with different molar ratios of [FeCl3] / [Pyrrole] in an aqueous medium, followed by a series of characterizations for the polymers obtained. Won the right ratio was used for the preparation of nanocomposites PPy (Cl) / HY Zeolite. After each synthesis, the developed product is characterized by FTIR, SEM, UV-Vis, XRD, and electrical conductivity in order to confirm the success of the process of synthesis and study their properties to specific applications envisaged. Keywords: nanocomposite, polypyrrole, zeolite HY, conductor polymer

Abstract: Coatings obtained on cellulose fabrics with nonionic dyes – silica hybrids have been investigated. Composition of the impregnation bath and parameters having a major influence on coloring properties were studied in relationship with washing and light fastness. It was found that cotton can be coated with organic-inorganic nonionic dyes - silica hybrids exhibiting fair washing and light fastness. Properties of the coated materials can be controlled by variation of parameters affecting sol obtaining procedures or impregnation conditions. The presence of only one trialkoxysilane group per chromogen makes the formation of a highly crosslinked silica network to be difficult. The partial condensation of DR1-PTES (Disperse Red 1 dye covalently linked to 3-isocyanatopropyltriethoxysilane) to the stage of oligomeric structures, together with the existence of silanol and unhydrolyzed alkoxysilane groups can explain leaching behavior of the coatings obtained with this type of hybrid materials. Keywords: nonionic dyes, silica hybrids, surface coating, cotton fabrics, sol-gel process

Abstract: This paper presents the synthesis of some acrylic monomers with pendant carbazole groups. They were copolymerized with N-octyl methacrylate to obtain organic photosensitive materials used in the production of holograms with electrophotographic methods. Keywords: N-vinylcarbazole, N (2-hydroxymethyl carbazole), N-carbazolyl methlacrylate, octylmethacrylate

Abstract: This paper presents the influence of processing temperatures of high-density polyethylene (HDPE), polymethyl methacrylate (PMMA), polycarbonate and acrylonitrile butadiene styrene blend (PC+ABS) on some mechanical properties when obtained through the injection of items from various industries. The HDPE samples were obtained at the following injection temperatures: 180, 190, 200, 210, and 220°C. The PMMA samples were obtained at the following injection temperatures: 220, 230, 240, 250, and 260°C, and PC+ABS samples were obtained at the following injection temperatures: 230, 240, 250, 260, and 270°C. Determining the mechanical properties was made using determining methods of tensile properties, of Izod impact test, and Shore Durometer hardness test. It was observed in the case of the three analyzed polymers that increasing the processing temperature hardly influences their respective hardness. The Izod shock resistance for the three analyzed polymers decreases along with the increase of the processing temperature by injection. The tensile strength at break is influenced by the processing temperature. The increase of the processing temperatures by injection in the case of the three analyzed polymers leads to the decrease of the tensile strength at break. The lowest values of the tensile strength at break occur at the highest processing temperatures. Keywords: high density polyethylene (HDPE), polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene polycarbonate blend (PC+ABS), tensile tests, Izod impact test, Shore Durometer hardness test

Abstract: Functionalization of multiwalled carbon nanotubes with carboxyl group (–COOH) and oxaliplatin (OX) was investigated using FTIR spectroscopy, high performance liquid cromatography (HPLC), transmission electron microscopy (TEM), inductively coupled plasma mass spectrometry (ICP-MS). Encapsulation efficiency was computed and in vitro behavior regarding MDA-MB-231 cells was studied. Keywords: carbon nanotubes, oxaliplatin, encapsulation, FTIR, TEM

Abstract: This paper addresses the theoretical and experimental mechanical properties of specific to monolayer composite plates produced from urban and industrial recycling wastes with elastomeric matrix and fibrous protein reinforcement (leather, textile). Defining the theoretical model of composite material with its structural elements, as well as evaluating physical and mechanical characteristics essential to its default drive to an optimal and efficient design of all products made from such materials. By determining the theoretical and experimental parameters with maximum precision, which affects the properties of the composite structure, it is decided its use in specific technical industrial applications. Keywords: composite material, reinforced lamina, recyclable waste, fibrous material.

Abstract: Tests on wearing clothes are complex methods of analysis that mainly consist of recordings of physiological reactions in the body. During wearing tests physical parameters of the environment and biometric parameters were measured. Five garments, blouses, were tested under dynamic conditions; the products were worn by 5 subjects, female students. In the performed tests there were determined the following parameters: the skin temperature and the electrical resistance of the skin, under dynamic wearing conditions (repose, effort, recovery). The study demonstrated that the tests of wearing garments under certain conditions, through their complexity, provide a series of information and emphasize certain aspects that cannot be found in the laboratory tests results on textile materials. The performance of these types of tests and the accomplishment of the objectives imply the contribution of complex teams. Only through an interdisciplinary approach can the issues regarding wear comfort be solved. Keywords: clothing, wear tests, warm environment, dynamic conditions, comfort, evaluation, biometric parameters

Abstract: The manufacturing of hydraulic turbine runners designed for experimental research on the model is carried out, usually, by precision casting or CNC machining. These processes involve technological difficulties, high manufacturing times and high production costs, which are generated by the complex geometry and the small dimensions of the runner. Rapid prototyping technologies allow the manufacturing of mechanical components at a high precision and for a significantly lower manufacturing time and production costs compared to the conventional technologies. The use of components made of polymers, through rapid prototyping, in experimental research, may be limited by the properties of the polymer and the mechanical stress occurred. In order to verify the possibility of using polymers in the manufacture of turbine component models, a Pelton runner was made through rapid prototyping. The stress-strain state that occurs on the runner blade was analyzed and experimental investigations were performed on a micro-turbine equipped with the polymer runner. Keywords: polymer, rapid prototyping, stress, Pelton runner

Abstract: To determine if acrylic or composite resins are favorable choices for the single crown on implants. It was performed a FE Analysis using the IBM Autodesk Inventor 2014 for a single 3.75x8mm mandibular implant, a straight titanium abutment, three crowns (acrylic, metal-composite and metal-ceramic) and a type III bone with a 1mm cortical component. For the implant, the maximum stress was 178.7MPa (acrylic crown), 96.38MPa (metal-composite crown) and 86.17MPa (metal-ceramic crown). For the abutment, the maximum stress was 312.4MPa (acrylic crown), 140.8MPa (metal-composite crown), and 121.5MPa (metal-ceramic crown). For the retainer screw, the maximum stress was 75.67MPa (acrylic crown), 33.66MPa (metalcomposite crown), and 34.64MPa (metal-ceramic crown). For the metallic component of the crown, the maximum stress was 248.7MPa (metal-composite crown), and 207.1MPa (metal-ceramic crown). For the aesthetic component of the crown, the maximum stress was 28.93MPa (acrylic crown), 22.45MPa (metalcomposite crown), and 28.13MPa (metal-ceramic crown). For the cortical bone, the maximum stress was 62.74MPa (acrylic crown), 37.63MPa (metal-composite crown), and 40.3MPa (metal-ceramic crown). For the trabecular bone, the maximum stress was 7.147MPa (acrylic crown), 4.995MPa (metal-composite crown), and 4.973MPa (metal-ceramic crown). For the metal-composite crown, the stress distribution in the trabecular bone is more uniform, comparing to the acrylic crown, which is an advantage. For the metalceramic crown the stress distribution in both bone components is similar as for metal-composite crown. The safety factor shows that there is no risk of plastic deformation, nor for acrylic or for the composite resins. The composite resin on Cr-Ni alloys is still the best material for the single implant crown. The acrylic resin and ceramics on Cr-Ni alloys proved a similar resistance to stresses. Keywords: acrylic crown, metal-composite crown, single implant, FEA

Abstract: Hernia prostheses have become, naturally, the standard in the surgical treatment of parietal defects. The development of this surgery led, besides the general complications relating to the surgery, to the occurrence of complications due to the prosthetic material used. Septic complications due to prosthetic material are difficult to treat, with long-term evolution and decrease in the patient’s quality of life. The objective of this study is to demonstrate that the incidence of septic complications can be reduced if morphological properties and clinical implications of the implants are known. Prosthesis susceptibility to infection is directly related to its structure, porosity and type of filament, these being the main criteria to be taken into account, especially when intra-operative septic times are expected. In conclusion, the incidence of chronic sepsis can be reduced by choosing, when clinical conditions allow, monofilament macroporous materials less susceptible to chronic infection. Key words: mesh infection, hernia, mesh porosity, polypropylene, ePTFE, polyester

Abstract: The work is part of a larger study, representing second note, being focused on the correlation between the behaviour of polymeric materials as such or as copolymers from the group of methyl methacrylate, maleic anhydride and silicone rubber, reinforced or not with polyethylene fiber and metallic copper mesh with antifungal activity for 12 matrix polymer systems used in removable prosthesis and the final, respectively. Keywords: silicone and acrylic resin, maleic anhydride, removable prosthesis, traction resistance, modulus of elasticity, Poisson’s coefficient, fungal activity

Abstract: Failure of progressive cavity pumps used in oil extraction is mainly due to damage of the elastomer subjected to time-varying load cycles and intensive processes of degradation by abrasive wear. In order to increase the lifetime of progressive cavity pumps is very important to not degrade the elastomer under the influence of operating conditions and working environment. The present paper has the main objective to study the fatigue behaviour of three type of elastomers used for progressive cavity pumps manufacture. Keywords: variable load cycles, progressive cavity pump, elastomer

Abstract: Viscosupplementation (intra-articular supplementation of hyaluronic acid - HA) provides a useful alternative in treating osteo-arthritis patients and it is included in the professional guidelines for treatment of the disease in knee joint. Rheological investigations add an important element to viscosupplements characterization. In order to improve the hyaluronic acid concentration in currently commercial viscoelastic solution but also for targeted release on the clinical needs, we propose to use the magnetic nanoparticles functionalized with hyaluronic acid. In this paper, we analyze the rheological properties of some experimental viscoelastic solutions obtained after the modification of the commercial viscoelastic solution with a concentration of 40 mg/2mL HA (Arthrum) using different concentration of functionalized magnetic nanoparticles, using a Paar – Physica MC 301 Rheometer. The results indicate improved viscoelastic properties with increased HA concentration. Solutions with lower viscosity are much less effective in converting mechanical energy into elastic deformation and the effect being more visible with time. Keywords: sodium hyaluronate, concentration, ferromagnetic nanoparticles, rheology

Abstract: Effects of Quantitative Changes on Drinking Water Quality Indicators of Urban Distribution Networks ION MIREL1, CONSTANTIN FLORESCU1, ALINA GIRBACIU1, CRISTIAN GIRBACIU1, PAVEL DUMITRU1, SORIN DAN2, RAMONA AMINA POPOVICI3*, GEORGE-LUCIAN IONESCU4 1 Politehnica University of Timiºoara, Civil Engineering Faculty, Hydrotechnical Engineering Department, 1A George Enescu Str., 300022, Timiºoara, Romania 2 Politehnica University of Timiºoara, Civil Engineering Faculty, Civil Engineering and Building Services Engineering Department, 2 Traian Lalescu Str., 300223, Timiºoara, Romania 3 “Victor Babes” University of Medine and Pharmacy Timisoara, 2 Eftimie Murgu Sq., 300041, Timisoara, Romania 4 University of Oradea, Faculty of Constructions and Architecture, 4 Barbu Stefanescu Delavrancea Str., 410058, Oradea, Romania In this paper are shown quantitative and qualitative changes in the drinking water distribution system, occurring in an urban locality with about 200 000 inhabitants in which water consumption over the past decade have been reduced by 50%. In relation to consumer debts are highlighted oscillations related to water pressure in the system and residual chlorine concentration on pressure zones. Hydraulic modeling of the water distribution system was performed using computer programming software, EPANET type, program that performs hydraulic simulations and water quality in pressure pipeline network. After analyzing and interpreting the results of hydraulic simulations performed in different operational situations (consumption 100; 75; 50%) resulted in areas where residual chlorine levels fall well below the limits imposed by the laws and regulations in force. In this situation are required corrective measures on water quality by reducing or eliminating water stagnation by increasing the velocity of the water circulation pipe sections affected. The book is useful for units or operators that use water networks in areas with significant debt fluctuations where by reducing travel speeds on sections of pipeline in areas where residual chlorine drops below the limits, favoring the formation of ecosystems biological and thereby triggering internal processes of auto-pollution reflected in the degradation of water supplied to consumers. Keywords: disinfection, residual chlorine, stagnation, water demand, pressure

Abstract: In-homogeneity, anisotropy, abrasiveness, and low thermal conductivity of glass fibre-reinforced polymeric composites make their machining more difficult as compared to metals. This fact explains numerous machinability studies that were carried out for some of these materials. The experiments presented in this paper were devised to assess the machinability in drilling process of a Romanian made glass fibre-reinforced polymeric composite. Keywords: polymeric composites, machinability, drilling

Abstract: A post-mortem examination of an 8 years old German Shepherd dog was performed in order to find out the death cause. The macroscopically examination revealed a large amount of blood in the abdominal (hemoperitoneum) and pericardial cavity (hemopericardium) and also the rupture of the right atrium. The spleen was sampled for histopathological examination. Hematoxylin-eosin–methylene blue staining was performed in order to prepare the samples for microscopical examination. Based on the specific histopathological changes and taking into account all the pathological data, the diagnosis was hemangiosarcoma. Key words: hemangiosarcoma, German Shepherd dog, hematoxylin-eosin–methylene blue staining

Abstract: The study compares the environmental impacts of 500 mL water bottles produced from corn-based polylactide (PLA) and PET. The results of cradle-to-bottle factory gate assessment revealed that the usage of PLA granules instead of PET granules would reduce the net global warming potential and cumulative nonrenewable energy demand of bottles by 30.9% and 32%, respectively. However, if no credits are given for atmospheric CO2 fixed by corn, and the energy in corn-feedstock is accounted for, the advantages of PLA would be largely diminished. Keywords: polylactide, PET, bottles, life cycle assessment

Abstract: Orthodontic treatment with the clear plastic aligner is becoming one of the most popular treatment options among adults and teenagers. The high precision of the virtual planning of the case leads to well fitted thermoformed plastic aligners and an individualized treatment for each patient. Several cases were treated with Clear Aligner therapy. All treatment outcomes were previsualized with the digital OrthoAnalyzer CAD software (3Shape) in order to design specific appliances for specific dental movements, with a lower risk of root resorption or other secondary effects. All desired dental movements can be measured and then transposed into a series of amorphous plastic aligners. Patient compliance and communication with the dental laboratory are enhanced due to the continuous developing of the CAD/CAM technology and Clear Aligner system. Keywords: digital setup, OrthoAnalyzer, plastic aligners

Abstract: The paper presents, from a comparative point of view, methods to increase the controllability of a drone. An important step in increasing the controllability is using light weight and resistant materials for the rotating parts of the drone. Also, the controllability can be increased by studying the structure of the propeller in order to reduce its moment of inertia. Keywords: drone, moment of inertia, propeller, controllability, carbon fibre

Abstract: The prediction of polymer properties, based on its composition, it is a complex problem with no easy method to obtain directly and accurately results. Among the tribological properties, the friction coefficient and wear rate are the most interesting ones. The polymers based on epoxy resin, with clay as filler, show different properties depending on the clay concentration. This paper presents an analysis of the polymer properties variation with its filler concentration. Due to the tribological processes complexity, mechanical and thermal properties must be taken into account. The aim of this study is to find an optimal concentration value, with minimal influence on polymer properties, using neural network models. All value properties were used in order to optimize and predict the composite properties. Keywords: polymer properties, tribology, filler concentration, neural network, prediction

Abstract: This paper had as special-purpose rendering the enhancing of WNR. 1.2083 steel’s properties by vacuum heat treatment, in protective atmosphere, in order to find adequate solutions for the improvement of the tools destined for the injection molding of PBT reinforced with up to 45% fiberglass, for the total cost of a mold production project divided per the total number of the resulted pieces from that project to reach its minimum value. For that purpose to be achieved, the use of high performance steels with special alloying concept and distinct production technique is mandatory. Although the electroslag remelting process ensures a smaller number of non-metallic inclusions and a homogenous structure characterized by isotropic properties, this has to be extended after heat treatment also. By identifying the problems involved in the injection process PBT reinforced with up to 45% fiberglass, the right characteristics of the WNR. 1.2083 steel were established. In order for those characteristics to be reached, the execution of the proper heat treatment in vacuum furnaces, with protected atmosphere, will be presented in this paper. Keywords: reinforced PBT, fiberglass, heat treatment, vacuum, low tempering, distortion

Abstract: This work investigates the mechanical properties of polyurethane rigid foams by means of Dynamic Mechanical Analysis (DMA) tests and Impulse Excitation Technique (IET). DMA tests were performed in single cantilever with a sweep in temperature (from -50 °C to 100 °C) and frequency (from 1 Hz to 100 Hz), not determining glass-transition in the test parameter interval. IET tests were used to determine the dynamic modulus of elasticity, showing good accordance with DMA results Keywords: PUR foams, DMA tests, impulse excitation technique

Abstract: The aim of the present study was to compare the retention rate and caries-preventive efficiency of two types of sealing materials : a glass ionomer cement (Ionofil plus) and a nano-hybrid resin sealant ( Grandio Seal) over a 2-year period. 84.78% with resin composite sealings and 7.39% of the glassionomer sealings were fully retained. New caries lesions were found in 7.82% of the glass ionomer sealed surfaces and 5.65% of the resin sealed surfaces. It can be concluded that Ionofil plus and Grandio Seal exhibit similar caries preventive effects. Keywords: dental sealing; Ionofil plus; Grandio Seal; retention rate; caries outcome

Abstract: Severe plastic deformation (SPD) is a manufacturing technique for producing bulk ultrafine grained materials and nanomaterials, the advanced grain refinement obtained by SPD substantially improving structural and physico-mechanical characteristics for the processed material. Equal-channel angular pressing (ECAP), the main SPD technology, entails pressing test samples through a die containing two channels equal in cross section and intersecting at a certain angle. The billet theoretically deforms by simple shear and retains the same cross sectional area to allow repeated pressings for several cycles. A commercial Al-Mg-Si alloy (6063- T1) was investigated in this study. As-received 6063-T1 alloy was firstly analyzed in OES and XRD tests. The specimens were subsequently processed at ambient temperature for a number of passes up to nine (one, three, six and nine ECAP passes), using a die channel angle of 100°. After ECAP, samples were cut from each specimen (ECAP treated and as-received) and prepared for microstructural investigations (SEM) and mechanical testing (compression and microhardness tests, fracture surfaces analysis). Furthermore, multiple correlations between ECAP processing parameters and the resulting microstructure and mechanical properties for the ECAP treated 6063-T1 alloy were also determined. Keywords: ultrafine-grained materials, aluminum alloys, severe plastic deformation, equal-channel angular pressing

Abstract: Hormones are chemical substances which transmit a message as a signal within a physiological system between the place where they are secreted and the place of their receptors where they have the biological action. In the last decades the number of studies on phytohormones has increased continuously. In this study, polyurethane microstructures with and without brassinolide were synthesized in order to assess the release rate. Two different types of drug carriers were obtained (ether- and ester-based microstructures) and the evaluations were done by using two different methods: the measurement of microstructures’ size and the determination of free brassinolide concentration. The results suggest that ester-based polyurethane microstructures degrade faster and the two methods present very similar results. Keywords: brassinolide, drug carrier, DSC, polyurethane, UV-Vis, zetasizer

Abstract: An increasing number of railway vehicles are using rubber springs as suspension elastic elements. Rubber is a suitable material for suspension purposes due to of its intrinsic properties and due to of the variety of forms into which it can be made. The clouth-type rubber spring may be used in both primary and secondary suspension of the vehicle and it may ensure the desired characteristics by setting the shape of its metallic components. In the present paper, a finite element static analysis was performed regarding the deformation of the clouth spring rubber under the action of various loads: vertical, longitudinal and transversal. The simulations allowed determining the distribution of deformations within the rubber element, the magnitude and the location of the largest deformation. Keywords: rubber, railway vehicle, suspension, clouth-type spring

Abstract: Polyester coating of copper alloys is part of the technological procedures meant to improve the performances of metallic parts in order to reduce the rate of premature removal from operation. The paper highlights the positive influence that copper alloys coating with polyester impregnated with 5 - 10% graphite has on the main mechanical characteristics, especially the wear resistance. The effects on the wear, fragility and structural modifications have been determined on Amsler testing machine by means of roller-roller type couplings: polyester coated copper alloy – treated copper alloy; treated copper alloy - treated copper alloy. The comparison revealed the positive influence of the thin layer of polyester as lubricating agent, thermal barrier, electrical insulator, damping layer, and stress dissipation medium it also established the temperature limit up to which it is recommended to use the polyester coating in industrial applications. Keywords: polyester, graphite, cooper alloys

Abstract: The paper presents comparative analysis for different solutions for the body of an internal spur gear used in a ground movement system of a drone with aerial and terrestrial movement capability. The comparative analysis is made from natural frequencies perspective and the purpose of the analysis is to reduce the weight of the drone without affecting its mechanical resistance and vibrational characteristics. Keywords: internal spur gear, modal analysis, natural frequencies, drone

Abstract: This paper presents the influence of subsequent pressure of high-density polyethylene (HDPE), polymethyl methacrylate (PMMA), polycarbonate and acrylonitrile butadiene styrene blend (PC+ABS) on some mechanical properties when obtained through the injection of items from various industries. The HDPE samples were obtained at the following subsequent pressure: 800 bar, 900 bar, 1000 bar, 1100 bar, and 1200 bar. The PMMA samples were obtained at the following subsequent pressure: 450 bar, 550 bar, 650 bar, 750 bar, and 850 bar, and PC+ABS samples were obtained at the following subsequent pressure: 500 bar, 600 bar, 700 bar, 800 bar, and 900 bar. Determining the mechanical properties was made using determining methods of tensile properties, of Izod impact test, and Shore Durometer hardness test. It was observed in the case of the three analyzed polymers that increasing the subsequent pressure when injecting HDPE leads to a slight increase of hardness, and in the case of PMMA and PC+ABS blend, an increase in the subsequent pressure leads to a decrease in hardness. The Izod shock resistance for HDPE and PMMA decreases along with the increase of the subsequent pressure. In the case of PC+ABS, an increase of the subsequent pressure from 500 bar to 700 bar leads to a decrease in the shock resistance from 68.675 kJ/m² to 51.475 kJ/m². A further increase in the subsequent pressure to 900 bar leads to an increase in the shock resistance up to 63.900 kJ/m². The tensile strength at break is influenced by the subsequent pressure. An increase in the subsequent pressure in case of HDPE and PC+ABS blend leads to an increase in the resistance of the tensile strength at break, whereas in the case of PMMA, an increase in the subsequent pressure leads to a decrease in the resistance of the tensile strength at break. Keywords: high density polyethylene (HDPE), polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene polycarbonate blend (PC+ABS), tensile tests, Izod impact test, Shore Durometer hardness test

Abstract: In the medical field of plastics is and will be most useful. Their processing involves engineering concepts which assumes the most diverse risks. But there are conditions, depending on the identification between offer and demand of such services. They come as effects of the concrete availability of resources of all types, of caring facilities, comparing with the demand based on the need for health. In this context the analysis due to risk engineering is appropriate in the management accomplishments of the processors, respectively as it can be used at national and international levels, having effects on the efficiency of the usage of al the involved resources. Keywords: industrial system, risk engineering, plastic materials

Abstract: The placenta handles the exchange of oxygen and nutrients from the mother to the fetus. Normal placentation and placental development are critical for a successful pregnancy. In this study, the placenta is obtained from normal pregnancy and of normal vaginal delivery. The polymeric cast of the fetal vasculature of the full-term placenta is used to perform a numerical simulation of the blood perfusion in the placenta. Vascular corrosion casting is an established method of anatomical preparation that has proven to be an an excellent tool for detailed three-dimensional (3D) morphological examination of normal and pathological microcirculation. Performed numerical simulation indicated that the velocity profiles in the placental vessels are close to parabolic profiles. Keywords: placenta, corrosion cast, numerical simulation, fetoplacental vasculature

Abstract: In the European Union, the concept of sustainable development covers all the environmental fields, from development politics to the appropriate management of waste, in respect to the future generations. Therefore, the aim of this study is to prove that electronic waste scraps can be used to manufacture a new modern and ecological composite material, which can be used in construction field. The Electric and Electronic Equipment (EEE) amounts, on the market, are increasing from one year to another. At the end of life, only half of the generated waste, named e-waste or Waste of Electric and Electronic Equipment (WEEE), is collected. Knowing that the e-waste is framed as hazardous waste, because of its hazardous substances content, the challenge of our society is safe recycling, to confer security to human health and environment. The obtained composite is a new material which contains cathode ray tubes (CRT) glass waste and plastic scraps from WEEE. The composite experimental strength results (39.24 N/mm2), entitled its classification into the mortars category. The WEEE recycling method used to obtain this type of composite is an environmentally friendly one. Keywords: cathode ray tubes (CRT), composite, plastic, waste recovery

Abstract: This paper deals with the analysis of temperature effect over the viscosity of the polymeric mixtures used in plastination studies. Two reaction mixtures were prepared respecting the standard protocol of the Biodur S10/15 technique. For these two mixtures, viscosity measurements were performed at -25 °C, +20 °C and +40 °C, after one day, one week, two weeks, three weeks and four weeks, respectively after preparation. These parameters were chosen rationally, since the standard impregnation time for the cold silicone method is three weeks. These results were also corroborated to the acetones’ vapor pressure, showing that for Biodur silicone, impregnation at room temperature is possible. A maximum of two weeks of impregnation was determined for S10, while for S15, this could be realized over a period of three weeks. Keywords: silicone viscosity, impregnation, S10/S15 technique, room temperature, cold method plastination

Abstract: In this paper, were determined the mechanical properties for Dammar based composite materials. For the begining, were determined the mechanical properties (elasticity modulus, breaking strength, breaking elongation, transversal Poisson ratio) for samples made from a resin whose Dammar is its main part. Based on this resin, were made composite materials, using as reinforcement fabrics from cotton, silk, flax and hemp. For each composite type were experimentally determined the same mechanical properties as in the case of resin based samples. Keywords: textile composites, mechanical properties, stress/strain curves, elastic properties, fractography

Abstract: On a total of 150 renal corrosion casts with a single renal artery, the artery of superior segment was examined. Three morphological types have been highlighted: Type I, in which the superior segmental artery originating directly in the trunk of the renal artery (8.67% of cases); Type II, in which the superior segmental artery arises from the anterior branch of the renal artery (81.33% of cases); Type III, in which the superior segmental artery arises from the posterior branch of the renal artery (10% of cases). In 78% of cases, the superior segmental artery arises independently from the trunk or renal artery branches (anterior or posterior). In 22% of cases, the superior segmental artery realizes a common trunk with one or more other segmental arteries. Knowledge of these aspects is important both to investigate morphological imaging and performing partial resection of the renal parenchyma. Keywords: kidney; corrosion casts; superior segmental artery; variations

Abstract: Dental composites, some of the most used materials in the last decade, have been and still are the focus of the researches in the last period of time. The present study aims to evaluate three of the most used composites given their different behaviour in practice. There were performed: the flexural strength test, the compression strength and resistance test at diametral compression according to ADA Sp.27/1993 specification. The results were surprising given the differences between the values obtained for the samples of each material. The study concludes that the variable properties of the composites in the same conditions originate from their inconstant microscopic structure. Keywords:dental composites, flexural strength test, compression strength, esistance test

Abstract: Membrane processes are a way to remove unwanted elements from wastewater stream. The permeability is an important parameter to filter wastewater and membrane fouling is of great interest in membrane filtration because reduce wastewater flow through the membrane. In order to improve the filtration process, many studies have investigated the use of nanoparticles added in the polymeric membranes and how much influence the permeation properties of membranes. A variety of nanoparticles have been used to modify polymer membranes, such as Al2O3, SiO2, TiO2, ZrO2, Fe3O4, Ag. Nanoparticles are used to improve the properties of membranes like hydrophilicity, permeability and fouling resistance. This paper shows the influence of the TiO2 nanoparticles with a concentration of 0.125 wt.%, on the permeation properties and dyes rejection of the PES and PSf membranes and makes a comparison with the results obtained by other authors. Keywords: TiO2 nanoparticles, PES, PSf, membranes

Abstract: Respiratory movements monitoring is critical in ensuring optimal patient supervision, especially in critical cases and also in diagnosing sleep apnea syndrome.The aim of our paper is to assess the possible role of magnetic impedance (MI) effect in respiratory movements recording.The study was carried out on 6 volunteers using a special mat equipped with quasi-non-contact MI sensors. Evaluation consisted in monitoring and recording the amplitude and frequency of the respiratory movements during normal breathing and while performing Valsalva maneuver.The constancy of pattern and amplitude of waves recorded suggests that this kind of respiratory movement monitoring may have considerable clinical application in monitoring critical patients and also sleep disorders, especially for children suspected of sleep apnea. Keywords: Amorphous Ferromagnetic Materials, Magneto impedance, Sensor, Breathing, Apnea