Volume 56, Issue 2

Abstract: A very common questionnaire, used to evaluate the health status of Chronic Obstructive Pulmonary Disease (COPD) patients, COPD assessment test (CAT), was applied to finding correlations between the items of CAT and other tests used in the same category of COPD patients. A sample of 56 male COPD patients, aged between 51 and 74 years, mean 63.86 (±5.55), half of them receiving long-term oxygen therapy, using transparent, hypoallergenic plastic masks or nasal cannulas, answered to CAT mostly choosing single items, statistically significant correlated with the Hospital Anxiety and Depression Scale scores (HADs), like walking up hills and stairs (r = 0.412, p[ 0.01), doing activities at home (r = 0.329, p[ 0.01), confidence leaving my home (r = 0.409, p[ 0.001), sleep (r = 0.277, p[ 0.01), and energy (r = 0.387, p[ 0.01), but CAT item walking up hills and stairs correlated better to 6 min walking distance (6MWD) (r = -0.581, p[ 0.01). The most significant correlations were found between 3 items of CAT as walking up hills and stairs, limitations doing activities at home and confidence leaving home in a most powerful and depression scores and 6MWD.

Abstract: Environmental problems that arise from acidic water containing aluminum generated from condensing thermal power plants can be suitably solved using membrane processes. In this paper, simultaneous neutralization with aluminum ion separation, from acidic waters containing aluminum traces, through permeation with polypropylene with inclusions of cellulose derivatives (PP / CellD)capillary composite membranes is approached. Cellulose derivatives considered are: acetylcellulose, carboxymethylcellulose, 2-hydroxyethyl cellulose, methyl 2 hydroxyethyl cellulose. The optimum working parameters for the best performance of composite membrane based on carboxymethylcellulose were determined: operating time and pH of the receiving phase. Simultaneously with the quantitative removal of the aluminum ions, it is obtained an almost neutral pH purified water, compatible with the natural waters in which it can be dispersed.

Abstract: The change of the organic bone cements’composition (COO) determines the adjustment of some important properties for the behaviour as fixing material, such as the: superficial tension, polarity, surface energy, viscosity, contraction at polymerisation, porosity. In the present paper we monitored the influence of the composition’s changes for some acrylic cements upon their handling features. The samples were obtained via the partial replacement of the methyl methacrylate (MMA) in the liquid phase of some usual formulas with another acrylic monomer. For these, it was measured the contact angles as wettablility of the fixing material. Moreover, it was estimated the values of the hardening time, important parameter for the application phases of the cements with cold hardening and fixing of the articular endoprostheses.

Abstract: The purpose of this experimental laboratory work is to obtain composite membranes having carbon and gold nanoparticles in the matrix. Consideration was made of using graphene oxide, a material which, under certain conditions, can generate membranes by a self-assembly process under vacuum in an aqueous or organic medium. The cellulose acetate (CA) - graphene oxide (GO) composite membranes have been functionalized with gold nanoparticles (AuNP) by two technological processes: thermal evaporation and ultrasonic mixing of stable graphene oxide and gold suspensions. The stable suspensions containing gold nanoparticles were obtained by chemical reduction of aqueous solutions of Tetrachloroauric acid trihydrate (HAuCl4) precursors with sodium citrate under high temperature conditions. Dispersibility of carbon nanostructures and precious metal nanoparticles has been studied with a DLS granulometer - Malvern Instruments Zetasizer ZS90. It was determined the mean particle size and Zeta potential function of the suspensions pH. The graphite based membranes were further subjected to various characterizations techniques. It was found that both the surfaces and the cross-sections were functionalized with gold particles. The presence of Au particles was revealed both on the membrane surface and also inside its structure. Hydrophilic tests demonstrate that the membrane filters have potential to be used in various applications.

Abstract: A facile and inexpensive approach was established to prepare spherical molecularly imprinted polymers with hypericin (H-MIPs) via the wet-phase inversion method. The H-MIPs were characterized by infrared spectroscopy and thermogravimetric analysis. High-performance liquid chromatography combined with UV–Visible spectroscopy were used to assess the efficiency of the extraction procedure and, furthermore, to investigate the recognition properties of the H-MIPs. Obtaining an imprinting factor of 3.38 for hypericin strongly indicated a successful formation of molecularly imprinted cavities onto the H-MIPs. A fair selectivity towards hypericin was tested in comparison to the interfering molecule pseudohypericin.

Abstract: Propolis is a natural apicultural product derived from plant resins with impressive health benefits. Its major biologically active substances are barely soluble in water, but this could be increased by proper formulations.The aim of the present study was to obtain a transmembrane delivery system based on polyurethane microstructures for eight propolis samples collected from different regions of Western Romania and to characterize them by differential scanning calorimetry (DSC); the assessed parameters were the particle size, the polydispersity index and their clustering tendency. Polyurethane polymers based on isophorone-diisocyanate and polyethylene glycol 200/ethylene glycol were chosen as carriers for the propolis extract. A perfect inclusion of propolis inside the structures was observed for half of the samples. Particle size ranged between 504 and 621 nm and was confirmed by the low stability against aggregation (Zeta potential: 16.3-19.8 mV). The polydispersity index was between 0.4 and 0.7.

Abstract: The new generation of newly developed materials, namely the high-crystallinity and high temperature polypropylene random copolymer, called PP-RCT, increases the crystalline capability of polypropylene, which allows pipes produced from this material to operate at higher pressures at elevated temperatures. Pressure tests on pipes made of PP-RCT materials show a resistance over a period of 50 years at 7000C (1580 F) 5 MPa (725 psi) compared with 3.2 MPa (464 psi) for standard materials PPR. By reinforcing PP-RCT with aluminum, glass and basalt composite results in a more resistant structure. As a result of the traction tests, it was found that in all three samples the tensile strength exceeds the manufacturer s limit (10 - 12.7 MPa), the values obtained being: st1 = 8 MPa - sample no. 1; st2 = 13 MPa - sample no. 2; st1 = 11 MPa - sample no. 3. The fiber glass insert is less resistant, the best variant being the basal insect sample (st2 = 13 MPa). Elongation at break for specimen no. 3 was recorded at 0.027 mm / mm. Tests on these material combinations were performed for stretching and flexing requests and compared to 3D created virtual models. Simulations of internal pressure behavior were also performed for different material configurations and the results were compared with the experimental data and the data supplied by the manufacturers.

Abstract: This paper shows the ageing study of some coatings and / or impregnation lacquers due to microbiological stress through fungal attack. Dielectric spectroscopy has shown that the dielectric losses of the investigated materials increase as result of microbiological ageing. The mean recorded increases are about 4 times for the alkyl-epoxy-melamine copolymer, 2 times for epoxy polymer and 1.5 times for urethane polymer in agreement with the mould coverage degree of about 20 %, 10 %, and 3 %, respectively. The fungal attack of the investigated polymers led to a decrease in volume resistivity of about 65 % for the alkyl-epoxy-melamine copolymer, 45 % for the epoxy polymer, and 14 % for polyurethane, in agreement with the increase of dielectric losses and degree of mold coverage of the samples. FTIR determinations have shown that fungal attack significantly increased the number of aliphatic -OH and C-H bonds and decreased the number of C–O bonds, respectively of C–O–C oxiran groups and C-C aromatic bonds. DSC thermograms recorded at different temperature ranges and the activation energies calculation for first major oxidation process indicate that after the fungal attack the thermooxidative reactivity of the investigated polymers increases.

Abstract: PLGA (Poli-lactic-co-glycolic acid) nanoparticles (NPs) are curently used as drug delivery systems for many types of drugs including antioxidants such as vitamin E. The main aim of our study was to test the antioxidant effects of PLGA-vitamin E on Wistar male rats. Two groups of Wistar rats received a hypercaloric diet for 21 days: the first group received besides the hypercaloric diet a daily dose of PLGA loaded with vitamin E and the control group received only the hypercaloric diet. Spleen cellular lysate has been used to detect biomarkers of oxidative stress such as malondialdehyde, glutathione, advanced human oxidative protein and vitamin E. After 3 weeks of treatment, statistical significant changes have been detected between the two groups.

Abstract: The aim of this study was to evaluate the efficiency in using intermaxillary elastics to stimulate mandibular growth and advancement in orthodontic patients diagnosed with skeletal Class II malocclusion as well as to compare the use of these Class II elastics in two different therapeutic approaches. The sample consisted of 60 orthodontic patients aged 10-15 years, 34 girls and 26 boys. The sample was divided into two equal groups (each consisting of 30 patients). Patients belonging to the first group (Group 1) were subjected to 1/4¹¹ - 6.0 oz elastics and were advised to change the elastic every 24 hours. Patients belonging to the second group (Group 2) were subjected to 1/4”- 4.5 oz elastics but with a recommendation to change the elastics every 12 hours. In order to evaluate the effectiveness of these two types of Class II elastics on mandibular growth and advancement, the value of the SNB angle at the beginning of the treatment (T1) was compared with the value of the SNB angle after 5 months of wearing intermaxillary elastics (T2). All patients showed statistically significant increased values of the SNB angle during the orthodontic treatment (p[0.001). Patients in Group 2 showed a significantly higher statistical increase (p[0.05) than patients in Group 1.

Abstract: The enterprise has an intricate and elaborate system of relationships between the departments, functioning closely as a cell within an organism, with its defined role within the market. In the complex context of actual economic system, resources are limited and enterprises seek for efficiency in order to reduce costs. In this paper we present the development of a solution for the optimization of an agricultural enterprise related to the plastic-based materials usage in the agricultural processes. In this matter, the experimental part consists in the creation of a model of a plastic management system using methodologies from the literature (e. g., System Dynamics or SD etc.) and its simulation with specific tools used traditionally. Besides the experimental part, we will make a short analysis regarding the structural and economic issues regarding plastics used in agriculture and some considerations regarding the bioplastic material that can be obtained from different types of agricultural waste.

Abstract: It was found that the obtaining of quality 3D printing filaments, without defects and natural color, from corn starch physical modified with PVOH, depends also on the melting behavior at compounding, both of starch and of PVOH, and on the controlling of the process sensitivity of the new compounds. A comparable melting behavior was possible by compounding the two polymers as powders with similar small sized particle. The controlling of the process sensitivity was achievable, mainly, by diminishing the melt resistance to flow, via formulation with a flow agent. The selected compounds which had controlled miscibility, few defects and natural color were shaped, with good results, as filaments with silky and smooth surface. These filaments were compatible with 3D printing because proved to have the ovality and the diameter tolerance in the accepted limits in the fields.

Abstract: The aim of this study was the development and formulating of an eye contour serum containing hyaluronic acid (HA) and the assessment of stability tests performed for the cosmetic product, transfered into a glass cosmetic bottle with polipropylene (PP) pump and cap. Sample of cosmetic serum were stored using 20 mL glass bottles with PP (Polypropylene) pump and cap. The developed cosmetic formulation was monitored under accelerated stability studies, performed over a period of 30 days while maintaining the product at 4, 20 and 40°C. Quality control initial, and after initiating the accelerated stability test was performed for the developed cosmetic formulation.

Abstract: Although Romania has a consistent hydro energetic potential, till now is valuated just approximate 30 percent of it. On the big rivers there are already installed high power hydro plants, but a lot of small and medium rivers are not valuated energetically. Installing a new high power hydro plant tends to affect the zone, being necessary a lot of changes in the environment. The Cross-Flow hydraulic turbines don’t need very complex hydro settlements, being very suitable for small and medium power hydro plants. Also a quite big potential in the use this type of hydraulic machines is the energy recovery in the water treatment and sewage plants. The turbine’s blades surfaces enters in contact with the pressurized water jet. The water jet creates a hydrodynamic force that tends to stress the blade. Mainly the Cross-flow turbine blades are made from steel. This article presents the hydrodynamic design and the possibility of using new polymeric material Delrin ®AF for the Cross-Flow turbine runner blades, together with the stress analysis.

Abstract: The present paper is concerning to an empirical analysis of tensile properties of plies and laminates formed with an epoxy matrix and with various carbon fiber fabrics. The analysis was started with the aim of finding some correlations between the elastic parameters of plies and elastic parameters of laminates when fabrics are used as reinforcements. Six different carbon fiber fabrics were used to analyze the plies and laminates mechanical parameters. The epoxy system Epiphen RE-4020-DE4020 was used in both cases as matrix. The mechanical response to tensile test was analyzed for above mentioned materials and the results had been compared with values obtained by application of various purposed models.

Abstract: The materials as well as the procedures successfully used in modern restorative dentistry are based on scientific selection criteria which can predict outstanding results both in terms of physiological aspects and durability of the workmanship. The rationale of using certain materials and the success or failure to use certain techniques have contributed in time to the evolution of restorative dentistry. The optimal way of combining the material with its application and finishing technique implies an exhaustive approach to the subject that still requires the specialists’ research and concern for their improvement and development. Among the restorative materials, those that meet the patients’ aesthetic exigencies are the composite resins. In spite of all the advantages resulting from their intrinsic characteristics, it should be noted though that composite resins still have inconveniences related in the first place to the polymerization contraction/shrinkage, which causes a gap between the obturation and the dental tissue further resulting in the generation of marginal micro-infiltrations with all the related drawbacks. Knowing the behavior of the material and understanding its use in various manners can help the practitioner in its efforts to minimize undesirable effects, which is generally possible by applying compensatory clinical techniques. The aim of the experimental research is to evaluate the marginal micro-infiltrations from the class II cavity restorations with composite diacrylic resins according to the different techniques of restoration (stratification technique, flow technique and pre-photopolymerized insert technique) and the establishment of the optimal restorative technique to minimize side effects.

Abstract: Low velocity impact tests were conducted on quasi-isotropic [±45/0/90o]xs laminates under drop weight impact from 0.7m, corresponding to a 30J energy. In this respect modified epoxy blends reinforced with carbon and Kevlar woven fabrics laminates were developed using autoclave technology. The four configurations developed for low velocity impact tests aimed at investigating several aspects like: the effect of fiber type, stacking sequence and mainly technological processing parameters, on the impact performances. The recorded Load-Time curves were plotted and visual inspection, high resolution laser scanner were used to observe the fracture characteristics of the impacted composite laminates. The results obtained showed that for tested configurations, both stacking sequence and processing parameters directly linked to fiber volume fraction, have a strong effect on the impact performances. The amount of absorbed energy, ductility index was calculated for each configuration under study. The results obtained showed that hybrid configuration exhibits lower stiffness and damage initiation energy amount when compared to carbon reinforced configurations. Nevertheless, their damage propagation energy amount and ductility index was the uppermost. This behaviour was already reported previously [1] and is partially attributed to the higher elastic energy absorption of carbon fibers that delays the propagation of delamination, and fiber breakage. Lower tenacity obtained on hybrid laminates was attributed to both lack of resin local rinse saturate and to the intrinsic anisotropy of para-aramid fibers.

Abstract: Carbapenem antibiotics resistance is a medical threat in antibacterial therapy as the pathogen resistant strains easily evolve a multi-drug resistance action to other incurable agents. The protective transport of current antibiotic molecules using nano-carriers initiates a huge approach in the antibacterial therapy, allowing the nanohybrids to defeat all these health threat pathogen agents. Chitosan is a linear cationic polysaccharide being often used in medical area as a biocompatible encapsulating agent in antibiotic delivery nanosystems. This work refers to encapsulation of imipenem into biodegradable chitosan nanoparticles in order to destroy antibiotic-resistant bacteria and limit the microbial adhesion and multiplication. Nanoparticles were prepared by ion gelation method using tripolyphosphate as cross linking agent. The obtained hybrid nanocapsules were then characterized and evaluated as a potential nano-device to beat antimicrobial resistance.

Abstract: The usual treatment for tuberculosis is difficult by its long-term therapy, raised dosing frequency and adverse effects of anti-tuberculosis drugs. Anionic clays, also called layered double hydroxides are a class of hydrotalcite like structures having high compositional variety and being able to self-assembly in the presence of drug molecules. The work refers to the development of nanohybrid materials like delivery systems that intercalates isonicotinic acid hydrazide, known as isoniazid anti-tuberculosis drug, into layered structure of hydrotalcite compounds. Loaded drug molecules of isoniazid were proved to be released in a controlled way from the as synthesized nanostructure in a simulated buffer solution. The obtained sample was characterized by advanced techniques thus demonstrating the inclusion of isoniazid antibiotic between hydrotalcite sheets. These results revealed important expectations for further researches of these organic-inorganic nanocomposites for tuberculosis treatment.

Abstract: Amoxicillin and clavulanic acid are two of the most commonly prescribed antibacterial worldwide for treating oral infectious diseases. Oral health is of big importance for well-being and general health. A few novel drug delivery systems were designed for oral treatment and prophylaxis of different diseases in the oral cavity. This work focused on the latest drug delivery development of the most common oral pathologies, namely, periodontitis, oral mucosal infections, dental caries and oral cancer. Herein we reveal the synthesis, characterization and application of chitosan nanoparticles for intracellular transport of the weakly cell-penetrating amoxicillin and clavulanic acid in order to improve their efficacy on bacterial infections.

Abstract: The main properties of dental adhesives should be good marginal adaptation, high retention strength and the possibility of not negatively influencing clinical sustainability. Dental adhesives are continuously improving to increase their retention to dental structures by increasing penetration in these structures, as it was shownin the in-vitro tests requiring imaging and qualitative analysis to allow the evaluation of experimental samples as well as the development of new materials. The main objective of this study is the qualitative and quantitative analysis of the layer of modified dental adhesives with ferrous nanoparticles encapsulated in a SiO2 membrane located between the surface of the dental preparation and the surface of the photopolymerizable composite filling. For qualitative and quantitative analysis of the samples, technologies such as SEM, optical microscopy and EDX were used.

Abstract: Aortic aneurysm (AA) and especially dissecting aneurism (DAA) represent life threatening medical conditions and vascular reconstruction surgery with the insertion of a vascular prosthetic grafts is often required to save patients life. In this paper we debate over the long term outcome of 23 patients who underwent five to eight years ago an aortic reconstruction surgery with insertion of Dacron grafts. They attended, during 2018, the emergency room of the County Emergency Hospital Pius Brinzeu of Timisoara in terms of patency complications of the prosthesis. Despite slight dilatation of the Dacron graft and of the native aorta, presence of mural thrombi and/or progress of aortic regurgitation, their evolution was satisfactory, without severe complications.

Abstract: The CAD/CAM technology has been successfully integrated in clinical and laboratory aspects of dental medicine. The present in vitro study focuses on the biochemical interactions between saliva and three types of polymeric resins for occlusal splints. Dental material samples were produced from 3D printed, milled and self-cured resins and were incubated with saliva samples from 20 healthy volunteers. The results showed that the 3D printed and milled polymeric resins did not produce any significant changes in oxidative stress parameters (uric acid, TAC, GGT, OXSR-1) or inflammatory markers (IL-2, IL-6). On the other hand, the self-cured acrylic resin produced a significant decrease in the salivary TAC and uric acid, the most important antioxidants in saliva, affecting the capacity of saliva to protect the oral environment against oxidative stress.

Abstract: Secondary autogenous bone grafting is the gold standard for the closure of an alveolar cleft. A preoperative surgical planning helps to determine the optimal shape and volume of the graft, that ideally guide canine eruption to the cleft area and ensure adequate nasal support. The authors describe their experience with design and use of an individually shaped 3D template for an autologous bone graft with fibrin glue for correct volume design. The conforming template is designed using freeware and open source software, it is manufactured by means of additive technology using autoclavable resin.

Abstract: This work reports the activation of polyurethane film surfaces in order to enrich them with polar groups such as -NH2, -OH, -COOH or radicals, which further allows immobilization of several bioactive compounds. UV-activation was used to introduce new groups on the polymer surface without affecting the bulk properties. The current arising species improve the wettability of the PU surfaces as it was observed from the static contact angle measurements. The structure and composition of the new PU surfaces were analyzed by using ATR-FTIR spectroscopy. The results suggested the possibility of modifying the PU surfaces in a shorter time periods, in order to provide many sites to attach other biomacromolecules by polar interaction or hydrogen bonding.

Abstract: Progress in Additive Manufacturing (AM) technology enables the fabrication of complex structures that could not be obtained with traditional manufacturing methods. One AM research area is the development and use of lightweight products with cellular structures, containing complex lattices and pores, which give improved performance and functionality. It is well known that there is a strong link between mechanical properties and architecture of samples with cellular structures. This paper presents a comparison and validation of Finite Element Analysis (FEA) simulations of cellular structures with experimental data obtained from compression tests, and degradation behaviour under load compression. The specimens, with spherical open-cells, were produced in VeroClear RGD810 photopolymer resin. Mechanical compression tests were performed to investigate the compressive behaviour and the mechanical response was registered in the form of compressive stress-strain curves. Also, using the specimens’ CAD data and compression test parameters, a Finite Element Analysis (FEA) was performed. A macroscopic analysis of the specimens’ structure and microhardness tests before and after compression tests were also carried out.

Abstract: Cross flow filtration is the typical way that water is filtered in membrane technology; that means that feed solution passes tangencially over the membrane and rejected components are washed away of the membrane by the rejected stream. In such a way, that minimal solids building up and at constant low flow resistance are achieved. In this paper, a calulation method regarding to the value of cross-section active area for a polymeric spiral wound reverse osmosis (RO) membrane is presented, in order to obtain the value of the cross-flow velocity of the system. This velocity is needed to improve the knowledge fouling mechanisms and it is not easy to know without obtaining the cross section area. To determine cross-section area of a RO polymeric spiral wound membrane a series of calculations were performed to obtain the initial values of some parameters. The mathematical calculation was also achieved with the Roll Length program. Based on the results obtained, it was concluded that only 65.36% of the total cross-section of the membrane is useful to cross flow and it was possible to determine the active cross-section of filtration with a value of 1,915.4 mm2, for the membrane studied. This methodology allows the calculation for any RO spiral membrane.

Abstract: Polyoxometalates (POM) are a class of inorganic compounds with various structures and remarkable electrical, magnetic and optical properties. Ion-pair complexes formed with some organic cations have high lipophilicity and they can be used as ionophores for PVC matrix membranes with active recognition function. The present study describes the construction and characterization of selective membrane sensors based on electroactive material incorporated in PVC matrix. They have been employed for the determination of ranitidine and nizatidine by using their complexes with silicotungstic acid as ionophores. The composition of the membrane has been optimized. The linear response range for both sensors was between 10-1-10-5M with quantification limits of 2.83·10-6M for ranitidine and 3.43·10-6M for nizatidine, and a response time shorter than 50 seconds. The new electrodes have been used for the potentiometrical determination of ranitidine and nizatidine in pharmaceutical products.

Abstract: The aim of this study was to evaluate the microhardness Rockwell and Young’s modulus of a new nano-hybrid and nano-fill composite resins exposed to corrosive media. The study was performed on two composite resins, one nano-hybrid and one nano-fill, enamel, dentine, translucent, respectively body shade, of which were made 20 samples (25.0 ± 0.1 mm lengths, 10.0 ± 0.1 mm widths and 3.0 ± 0.1 mm thicknesses), which were immersed in mouthwash for 1 minute per day for 10 days, the rest of the time being stored in artificial saliva. Measurements of Rockwell microhardness and Young‘s modulus on samples were made between on the first day, after 6 days and 10 days of immersion in mouthwash comparative with 0 day. The results showed that after immersion in the corrosive environment, both materials had the hardness values changed, but medium values of Rockwell microhardness to nano-fill composite resin were higher than nano-hybride. At the nano-hybride composite resin, it was observed that the enamel and clear translucent groups had the mean values increased after the first day of exposure to mouthwash, compared to the dentine group, which showed a higher mean value after 6 days. At the nano-fill composite resin, for the enamel and body groups were obtained the higher values of HRC after 10 days. For the dentine group, after 6 days, Filtek Ultimate showed the same variation as Harmonize dentine shade. Harmonize composite resin showed higher values of Rockwell microhardness and Young‘s modulus for all study groups compared to Filtek Ultimate.

Abstract: The aim of the work is conduct to highlight how the technological parameters has influence of 3D printed DLP on the generation of wheel, made from resin type material. In the first part of the paper is presents how to generate in terms of dimensional aspects specific design cylindrical gears, conical and worm gear. Generating elements intended to reduce the cost of manufacturing of these elements. Also are achieve the specific components of this work are put to test with a laboratory test stand which is presented in the paper in the third part of the paper. The tested gears generated by 3D-printed technique made with 3D printed with FDM or DLP technique. After the constructive aspects, proceed to the identification of conserved quantities, which have an impact both in terms of mechanical strength, but his cinematic, in order to achieve a product with kinematic features and good functional domain specific had in mind. The next part is carried out an analysis of the layers are generated using the DLP and FDM method using an optical microscope with magnification up to 500 times, specially adapted in order to achieve both visualization and measurement of specific elements. In the end part, it will highlight the main issues and the specific recommendations made to obtain such constructive mechanical elements.

Abstract: The paper describes the implementation of a new type of End-effector for testing touch screen devices. To automate the testing process of touch screens devices, a new type of end-effector is presented. The End-effector can be attached at diferent tipes of robotics sistem trough a connection part, which can be designed depending on the type of robot. For the movements in the test scenario, the end-effector is designed to move like a human hand. To create the physical parts in the prototype phase is used an field of rapid prototyping (RP) technology, called fused deposition modeling (FDM).

Abstract: Recent assessments show an increase in the incidence of tooth decay. In addition to prophylactic treatments using fluoride and diet focused on low sugar consumption, application of sealing materials to the teeth surfaces is the best protection against the appearance of dental caries on both temporary and permanent teeth.Tooth sealing applied using conventional method, plus the application of adhesive systems can lead to noticeable results over time.An increased thickness of the adhesive layer may lead to microinfiltration and implicitly to a failure of the dental caries protection therapy.Loading the dental adhesive with magnetic nanoparticles and applying it to the surface of the teeth with the help of a the magnetic field attempts to reduce and uniformize the thickness of the adhesive layer, which can lead to a reduced decrease in the occurrence of dental caries under the sealing materials for pit and fissures on the occlusal surfaces.

Abstract: Hydraulic turbine components that define the water flow, generally have a complex geometry. In the design of these components a major role is played by model tests. The complex geometry of runner’s blades and wicked gates determines high manufacturing times and high fabrication cost if they are made by classical manufacturing technologies (casting, machining on numerically controlled machines). The use of high resolution 3D printing reduces the production time, simplifies the manufacturing technology and generate high dimensional accuracy. The paper presents the design and the manufacturing process of the components from a new solution of axial hydroturbine, equipped with a permanent magnet generator and an immersed runner. The manufacturing of the main parts of the turbine (runner and wicked gates) it was made by Rapid Prototyping.

Abstract: The explosive effect and high velocity penetration of the ballistic projectiles of various sizes, design and compositions, on impact with different targets (armors composed of a combination of different metals) are complex. Both practical experiments and mathematical modeling of the phenomena associated to the interaction projectile-target are required to estimate their effect or to design more efficient projectiles and armor. In this study, the basic element of the simulation model is an incendiary projectile of caliber 7.62 mm with medium piercing power, launched with a maximum speed of 750 ms-1 on the multi-material target, which contains 4 different layers assembled into a ballistic cassette made of aluminum. The purpose of this ballistic cassette is to ensure a better contact and handling of multi-layer materials. The proposed model was calculated using mathematical modeling and empirical material constants to describe the nonlinear transitory impact process. Mathematical simulation of the impact between the projectile and target during impact shows that the projectile moves sequentially through the ballistic package, causing perforation, plastic deformation and heating, the resulting fragments being then expelled into the space around the target. The model indicates that the projectile will penetrate the front aluminum plate, as well as the AlCrFeCoNi and steel plates, but will be stopped by the aluminum backing plate. The real impact tests carried out using the ballistic cassette at dynamic impact with the 7.62mm incendiary projectile confirm the model assumptions, which prove the capacity of the composite model to safely stop the projectile.

Abstract: The automotive industry is one of the largest consumer of flexible hoses for fluids such as fuel or cooling. In order to limit the post production costs, every aspect of a vehicle must be tested in advance, including the lifespan, durability or failure of hoses. Throughout this paper summary results are presented for 4 types of fuel line hoses tested under controlled displacement loads at various pressures in order to validate the Finite Element Method simulations.

Abstract: The purpose of our study was to analyze the influence of Ti-6Al-4V and Ti-15Zr dental implants, with complex implant designs, on the cortical and trabecular mandibular bone in regards to the stress value and its distribution using finite element analysis. A total of four 3D implant assemblies were modeled, each consisting of implant, abutment, abutment screw, cement layer, and ceramic crown. Implants were modeled with different macrostructure designs with focus on the main thread and microthread design as well as complex geometry details. All implants were inserted in the second molar position in the mandible bone section, consisting of two macro-structures, a 2 mm thick cortical bone and an internal cancellous bone. Results revealed that small variations in the implant design led to a great difference in the stress values and distribution in both cortical and cancellous bone. Our results suggest no major difference between Ti-6Al-4V and Ti-15Zr in regards to the material’s ability to decrease stress in the periimplant bone. However, within the same material, results revealed important differences between thread design and implant geometry concerning the stress values and stress concentration in cortical and cancellous bone in the mandibular model.