Search

The development and diversification of machines and mechanisms with applications in all fields require new scientific researches for the systematization and improvement of existing mechanical systems by creating new mechanisms adapted to modern requirements, which involve increasingly complex topological structures. The modern industry, the practice of designing and building machinery is increasingly based on the results of scientific and applied research. Each industrial achievement has backed theoretical and experimental computer-assisted research, which solves increasingly complex problems with advanced computing programs using an increasingly specialized software. The robotization of technological processes determines and influences the emergence of new industries, applications under special environmental conditions, the approach of new types of technological operations, manipulation of objects in the alien space, teleoperators in the top disciplines like medicine, robots covering a whole field greater service provision in our modern, computerized society. Movable, robotic, mechatronic mechanical systems have entered nearly all industrial spheres. Today, we can no longer conceive of industrial production without these extremely useful systems. They are still said to steal from people's jobs. Even so, it should be made clear that these systems create value, work in difficult, repetitive, non-pausing, high-quality work, without getting tired, without getting sick, without salary and producing value who are paid and people left without jobs, so that they can work elsewhere in more pleasant, more advantageous conditions, with the necessary breaks. Mechanical systems in motion type parallel structures are solid, fast and accurate. Between mobile systems parallel the best known and used system is that of a Stewart platforms, as being and the oldest system, quickly, solid and accurate. The paper presents a few main elements of the Stewart platforms. In the case where a motto element consists of a structure composed of two elements in a relative movement from the point of view of the train of propulsion and especially in the dynamic calculations, it is more convenient to represent the motto element as a single moving item. The paper presents an exact, original analytical geometry method for determining the kinematic and dynamic parameters of a parallel mobile structure. Compared with other methods already known, the presented method has the great advantage of being an exact analytical method of calculation and not one iterative-approximately.

Despite research carried out around the world since the 1950s, no industrial application of fusion to energy production has yet succeeded, apart from nuclear weapons with the H-bomb, since this application does not aims at containing and controlling the reaction produced. There are, however, some other less mediated uses, such as neutron generators. The fusion of light nuclei releases enormous amounts of energy from the attraction between the nucleons due to the strong interaction (nuclear binding energy). Fusion it is with nuclear fission one of the two main types of nuclear reactions applied. The mass of the new atom obtained by the fusion is less than the sum of the masses of the two light atoms. In the process of fusion, part of the mass is transformed into energy in its simplest form: Heat. This loss is explained by the Einstein known formula E = mc2. Unlike nuclear fission, the fusion products themselves (mainly helium 4) are not radioactive, but when the reaction is used to emit fast neutrons, they can transform the nuclei that capture them into isotopes that some of them can be radioactive. In order to be able to start and to be maintained with the success the nuclear fusion reactions, it is first necessary to know all this reactions very well. This means that it is necessary to know both the main reactions that may take place in a nuclear reactor and their sense and effects. The main aim is to choose and coupling the most convenient reactions, forcing by technical means for their production in the reactor. Taking into account that there are a multitude of possible variants, it is necessary to consider in advance the solutions that we consider them optimal. The paper takes into account both variants of nuclear fusion and cold and hot. For each variant will be mentioned the minimum necessary specifications.

The development of new diamond based bio-mechanically active hybrid nano-structured scaffolds for cartilage cells tissue engineering are proposed in this study. Innovative tissue engineering biomimetic materials based on hydrogel have shown attractive physical, biological and mechanical properties in several biomedical applications. A highly biocompatible novel hybrid material based on nanodiamonds and hydrophilic poly-(hydroxyl-ethyl-methacrylate) (pHEMA) is proposed. The aim of this paper is to describe the chemical and analytical procedures for the preparation of nanofilled hybrid composites possessing biomimetic, osteoconductive and osteoinductivity properties that can be useful in the design of bio-mechanically active innovative bone scaffolding systems for stem cell differentiation and growth. A more rigid and rubber transparent hybrid nano-composites are predicted to posses improved mechanical strength overwhelming one of the major weaknesses of hydrogels, which is due their poor mechanical characteristics, for applications in biomedical structural application.

Dynamic-Mechanical Analysis (DMA), Differential scanning Calorimetry (DSC) and water moisture sorption-desorption kinetics and equilibria have been parallely investigated to monitoring the environmental and thermal sensitivity of amorphous thermoplastic Poly-Ether-Ether-Ketone (PEEK). Morphological modification occurring in PEEK during the calorimetric and thermo-mechanical characterizations and the hygrothermal stability are presented. An interpretation based on the free energy of mixing of a polymer chains with penetrant molecules and pseudo-equilibrium Flory-Huggins interaction parameter χ and related osmotic tension is proposed. The correlation between dynamic mechanical measurements and water saturation is discussed in terms of different levels of osmotic tension generated in the amorphous PEEK. From the analysis of the water diffusion coefficients in amorphous PEEK equilibrated at low and high activity environments, it has been found that even samples with very low water contents may undergo bulk matrix relaxation above 40°C.

Homeopathy or homoeopathy (from the Greek hómoios, “similar” and páthos, “suffering” or “disease”) is a science created by Samuel Hahnemann in 1796. The homeopathic practice rests on three principles: The similarity, the individualization of cases and the infinitesimal. The use of the infinitesimal was proposed by Hahnemann in the early nineteenth century with the publication of “Organon der Heilkunst” (Organon of the art of healing). The compounds used do not become homeopathic unless they respect the principle of similarity, according to which a patient should be treated with a substance producing experimentally in a healthy person symptoms similar to those presented by the affected person, use of the substance being adapted to the patient thanks to the principle of individualization according to which the homeopath analyzes all the symptoms of the person and not only those related to the disease. Substances chosen according to this method can be administered in non-toxic weighted doses, but most prescribers use them in dilutions, sometimes very large, which have previously been subjected to very high and very frequent vibrations. Although some clinical trials produce positive results, multiple systematic reviews indicate that this is due to chance, questionable research methods, or publication biases. Despite a certain popularity, the therapeutic efficacy of homeopathy has not been demonstrated as a general and permanent solution. The vast majority of the scientific and medical community considers that homeopathy is a pseudo-science coming into contradiction with current knowledge in chemistry and biology established after the fundamental principles of homeopathy themselves proposed more than two Centuries. In particular, they point out that certain homeopathic dilutions are such that the excipient no longer contains a single molecule of the diluted remedy and therefore can’t act chemically. Moreover, the fact that effects are observed is disputed by published meta-analyzes which conclude that homeopathy has not demonstrated its clinical efficacy beyond the placebo effect and yet, the Homeopathy works, despite some malicious feedback.

The implementation of the Ion Plating Plasma Assisted technology in the area of surface functionalization for structural color and relic preservation applications is presented. Interferometric structural colors on irregular bumped Titanium surfaces and transparent and achromatic nano films on ancient ceramic artifact have been investigated. Titanium metal and ceramic supports have been utilized for the surface functionalization tests: A metallic electron beam additive manufactured Titanium component and an ancient tile of the XIX century, which was characterized by strong chromatic valence and by a mixed porous and glazed surfaces, have been considered. A reactive magnetron sputtering Ion Plating Plasma Assisted apparatus operating in Argon or Oxygen atmospheres for TiO2 and SiO2 deposition has been utilized. Preliminary tests with two plasma treatments were carried out for optimal processing conditions definition. TiO2 nano-film deposition on irregular Ti surfaces has generated light direction depending color-changing surfaces while good achromatic and transparent coatings were obtained by using SiO2 coating. The high processing flexibility of the Ion plating technology is discussed. The SiO2 IPPA surfaces treatment resulted more convenient for restorative and preservation ancient historical tile was used to finally test the optimized process with Ion Beam Electron Microscopy, which was carried out on the tile porous structure, confirmed the high flexibility and efficiency of the innovative IPPA technology.

Segregation by selective cold crystallizations and glass transition changes in Zr44-Ti11-Cu10-Ni10-Be25 metal supercooled metastable liquid annealed at different temperatures have been theoretically correlated to melt viscosity modifications. Crystallization behavior has been found to be principally related to the high mobility and smaller Be, Cu and Ni atoms. Multiple exothermal peaks in isothermal DSC annealing’s have been observed in these bulk metal glassy supercooled liquids. A significant increase of the glass transitions temperatures were experimentally measured in cold crystallized samples. Isothermal and temperature scans by Differential Scanning Calorimetry have shown that the three smaller elements present in the alloy (namely Be, Ni and Cu) were involved in recrystallization process in the temperatures interval from glass transition to 470°C. Isothermal annealing’s at temperatures ranging from 400° to 450°C have been considered. Glass transitions and crystallization kinetics in the super-cooled liquid have been measured.

All synthetic and natural materials to be used in biomedical applications that involve the contact with human body need to be investigated for their physical and chemical modification induced by the human physiological fluids contact and sorption. The development and testing in human physiological equivalent fluids of new hybrid biomaterials are presented. The role of water and its equilibrium modification in the human physiology is discussed and the swelling and sorption behavior in the physiological environment of a nanostructured and osteoconductive biomaterials based on Poly-Hydroxyl-Ethyl-Meth Acrylate matrix (pHEMA) filled with fumed amorphous nanosilica particles is presented. This material differently swells in presence of aqueous physiological solution fluid. Biological hybrid scaffolds for bone regeneration and growth made using synthetic materials able to correctly interact with the physiological fluids while inducing the growth of biological tissues may favor the birth in the medical field of a new class of hybrid materials. Our multidisciplinary approach explores in the this paper, novel ideas in modeling, design and fabrication of new nanostructured scaffolding biomaterials with enhanced functionality and improved interaction with OB cells.

The application of Ion Plating Plasma Assisted technology in the field of preservation of Cultural Heritage is presented. In order to guaranty the preservation of the artistic and cultural identity of ancient ceramic tiles with strong chromatic valence, not-invasive, and achromatic and antireflective coating deposition processes have been investigated. Different ceramic supports have been utilized for the tests: an ancient tile of the XIX century and contemporaneous production tiles, all characterized by strong chromatic valence and by a mixed porous and glazed surfaces. Ion Plating Plasma Assisted (IPPA) by reactive magnetron sputtering source with Argon and Oxygen atmosphere for TiO2 and IPPA by thermal source with Argon and Oxygen from SiO material have been adopted. Preliminary tests with two plasma treatments were carried out on contemporaneous tile samples in order to find the optimal processing conditions. TiO2 treatment has generated discoloration on the surface of the coating while the SiO2 coating showed achromatic and transparency properties. The ancient historical tile was used to finally test the optimized process with SiO2. Traditional organic resin spray coating treatments have been carried out for aesthetical comparative purposes with the new plasma treatment.

Objectives: The present in vitro study aimed at evaluating the influence of a novel nanocomposite material on implant primary stability by means of periimplants scaffolds. Methods: Thirty-two titanium implants (Winsix, Biosafin) with an innovative design were modified with three-dimensional bioactive scaffolds made up of a new hybrid ceramo-polymeric material. The biomimetic nanocomposite material was designed to promote the precipitation of hydroxyapatite nanoinclusions in periimplant bone. The scaffolds were fabricated as a foamed hydrogel covering the coronal area of the implants; the material was characterized by swelling in contact with biological fluids, with a polymerization kinetic of 0.1 mm/hour. The modified implants were inserted in freshly explanted tibiae of minipigs; 16 standard implants were used as control. Then, the tibiae were kept hydrated in physiological solution and the implants removed after 1, 6, 12 and 24 hours. An electronic device was used to measure the removal torque and the data were statistically analyzed. Results: Insertion torque values ranging between 37 and 56 Ncm were recorded. Mean removal torque values of 61, 67, 79 and 86 were evidenced after 1, 6, 12 and 24 hours respectively. The ANOVA showed statistically significant differences between removal torque values (p

Objectives: The present prospective clinical study aimed at evaluating the clinical perfomances of tooth-supported 3-unit posterior zirconia FDPs after 8 years of service. Methods: Thirty-seven patients received 48 3-unit zirconia-based (Procera, NobelBiocare) FDPs. The prostheses replaced either a premolar or a molar. Specific inclusion criteria were used. Standardized tooth preparations were realized: 2mm occlusal reduction, 1.5mm axial reduction and circumferential chamfer shoulder placed 0.5 mm subgingivally buccally and supragingivally lingually on sound tooth structure; all internal angles were rounded. Impressions were made with polyethers (3M ESPE). CAD-CAM frameworks (Procera, NobelBiocare) with 9mm2 connector and 0.6mm retainer were made. The restorations were luted using a resin cement (RelyXUnicem, 3M ESPE). The patients were recalled after 1, 6 and 12 months after the cementation and then annually for a whole observational period of 8 years. Survival and success of the veneering ceramic and zirconia were assessed. The esthetic and technical outcomes were rated using the USPHS criteria. The biologic outcomes were analyzed at abutment and contralateral teeth. Descriptive statistics were performed (Kaplan-Meier, Wilcoxon). Results: All FDPs completed the study, resulting in 100% cumulative survival rate and 93.75% cumulative success rate. No losses of retention were recorded. Forty restorations were rated Alpha in all measured parameters. Minor chipping of ceramics was detected in 3 restorations. Four restorations were rated Bravo for marginal integrity at 8 years. No significant differences between the periodontal parameters of the test and control teeth were observed. As to esthetics, 42 restorations were rated Alpha and 6 were rated Bravo by both the clinicians and the patients at the 8-year follow-up. Conclusions: Eight-year clinical results showed that posterior 3-unit zirconia-based FDPs can be considered a viable treatment option in the medium-term. These restorations may be considered reliable to replace a posterior missing tooth.

Objectives: The present in vivo animal study aimed at evaluating the osseointegration of biomimetic bone scaffolds made up of an innovative nanocomposite material. Methods: A novel nanocomposite hybrid ceramo-polymeric material was designed and produced to interact with bone tissue at nanoscale interfaces. The chemical, physical and mechanical properties of the material were analyzed and characterized. The highly bioactive material was designed to fabricate three-dimensional bone scaffolds in order to promote osseointegration through the precipitation of hydroxyapatite nanoinclusions in periimplant bone. The biomimetic nanocomposite was fabricated as a foamed hydrogel swelling in contact with biological fluids. The biofidelity of the scaffolded implant system was simulated in a digital environment and the stress and strain distributions assessed using three-dimensional Finite Element Analysis. The biomimetic properties of the nanocomposite material were validated in vivo in an animal model, using three-dimensional scaffolds around dental implants inserted in tibiae of minipigs. After explantation, such tibiae were subjected to micro-computed tomography scannings to evaluate bone-to-implant and bone-to- scaffold contact. Results: The chemical, physical and mechanical laboratory tests showed high biomimetic properties for the innovative hybrid material. Stress and strain distributions within the physiological range of trabecular adaptive organization (2000-3000 με) were noticed in periimplant bone with the Finite Element Analysis. The micro-CT scannings showed comparable percentages of bone contact at level of both the scaffolds and the titanium of the implants. Conclusions: The innovative hybrid ceramo-polymeric nanomaterial proved to promote accelerated osseointegration in post-surgical early healing phases.

A biomimetic approach has been applied to design and realize new odontostomatological Titanium (Ti) implants using a multifunctional bioactive ceramopolymeric hybrid material. The proposed biomimetic/biomechanical approach consists in combining mechanical and physical characterization of the hybrid nanocomposite to biosolid mechanics Finite Element Analysis of the new design implants. Hybrid ceramopolymeric nanocomposites based on Hydroxyl-Ethyl-Methacrylate polymer (pHEMA) filled with nanosilica particles are presented as biomimetic-scaffolding materials. Cytotoxicity and Osteoblast cells adhesion tests have shown good material biocompatibility and osteoconductivity [1]. Dynamic Mechanical Analysis (DMA) confirmed the hybrid mechanical behaviour of these nanocomposites. Moreover, this class of material swells in presence of aqueous physiological solution according to limiting Case II sorption mode turning from glassy and rigid to soft and rubbery while presenting a mechanical behaviour, at 5 to 10 % nanosilica volume loadings, that is comparable with that of bone (when glassy) and to that of the cartilage and Ligaments (when rubbery). Materials swelling behaviour and mechanical characterizations are presented. Design criteria and FEM simulation are discussed. The use of mechanically compatible hybrid hydrogels as scaffolding materials are expected to increase prosthesis adaptation mechanisms introducing active interfaces that improve implant biomimetics while reproducing cartilage and ligaments biomechanical functions. [1] C Schiraldi, A D'Agostino, A Oliva, … R Aversa, M De Rosa, Biomaterials, 25 (17), 3645-3653 (2004). [2] R Aversa, D Apicella, L Perillo, R Sorrentino, F Zarone, M Ferrari, A Apicella, Dental Materials, 25(5), 678-690 (2009). [3] D Apicella, R Aversa, F Ferro, D Ianniello, A Apicella, J. of Biomedical Material Research: Part B, Applied Biomaterials, vol-93(1), 150-163 (2010).

"The research develops new hybrid biomimetic materials that work as mechanically stimulating “scaffolds” to promote early regeneration in implanted bone healing phases. A modified commercial odontostomatological implant has been biomechanically investigated by Finite Element Analysis. A biomimetic nanostructured osteoconductive material has been used to replace part of the implant screw. Combined material characterization (mechanical and aqueous media sorption behaviour) and computer-aided simulations have been carried out. Such biomimetic multidisciplinary approach allowed us to explore many novel ideas in modelling, design and use of new nanostructured biomaterials and devices with enhanced functionality and improved interaction with Osteoblast cells."

"Our study proposes an innovative integrated transportation\/photovoltaic energy system that will enable the Pompei municipality to develop a set of Urban Ecotourism policies and instruments for the preparation and adoption of a more environmental sustainable mobility strategies to be applied in their future PUC (Municipality Urban Plan). The innovative character of the study resides in two principal aspects: the technologies applied, namely, the use of thin film photovoltaic panels (copper-indium-gallium-(di)selenide cells) on flexible support and the way these technologies are applied. A combined energy\/mobility approach based on “Zero Km and Zero emission energy production for Zero Emission electric transportation strategy” to be implemented in the public Urban Plan (Piano Urbanistico Comunale) of the town of Pompei is presented. According to the technology to be adopted (thin PV film on flexible supports integrated in the parking shelters roofs), to the foreseen PV plant of 700 sqm parking lots and to an innovative multifunctional design approach (biomimicrying sun track roof), an improved yearly power production of 100.0 MWh is foreseen with a 20-25% increase of power production with respect to standard fixed PV panels of the same type."