Volume 54, Issue 3

Abstract: In this paper, optimum hot formation processing parameters for 31VMn12 steel were established, the torsion deformation of 31VMn12 steel was investigated at temperatures from 900, 1000, 11000C and strain rates from 0.05 s-1 to 3 s. –1. There were studied the structural aspects of materials, in microstructures by electronic microscopy. The stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by a Zenner-Hollomon parameter. The mathematical model presented in the paper describes the relationship of tension strain, voltage and temperature coefficient 31VMn12 steel at high temperatures. The stress-strain curves determined by the torsion test allowed the calculation of the Zenner–Hollomon parameter corresponding to the maximum stress. By using this parameter has established a set of equations that reproduce completely stress-strain curve, including the hardening, the restoration and dynamic recrystallization area. Comparisons were made between the experimental results and the predicted and confirmed that constitutive equations developed can be used for mathematical modelling and other attempts (forging, compression) and other types of steel.

Abstract: Breast reconstruction involves two major conditions: to be oncologically safe and to respect the aesthetic of the reconstructed breast. Moreover, every healthcare system in the world manifests a keen tendency to cut back on medical costs, which influences our surgical techniques and breast reconstruction procedures. The use of biological matrices like the acellular dermal matrix has become an acknowledged alternative in implant-based breast reconstruction, in spite of the many impediments and controversies that surround it. However, these matrices are costly and less attainable as compared to synthetic meshes that are conservative with resources and unyielding to the formation of biofilm bacteria. Accordingly, we decided to research the impact of synthetic meshes in implant-based breast reconstruction.

Abstract: The paper presents the research carried out by our team on achieving amphiphilic polymeric microcomposites, colored in ruby and violet shades for natural fibers dyeing (cotton, wool). The colored polymeric microcomposites were characterized in term of their morpholo- gical (by optical microscopy and SEM analysis) and physicochemical performancies (by FT-IR and UV-Vis spectroscopy, colorimetric analysis). The colored microcapsules were tested by studying the controlled release of the encapsulated dyes in water, to pH variation. This study was necessary to the coloristic characterization of colored polymeric microcomposites to determine the optimal microcapsules dye concentration and dyeing concentration of natural fibers.

Abstract: In the paper it is presented a new Euler – Bernoulli theory based on an assymetrical distribution of strains towards the median plane, the area subjected to compression has a transversal stretching, while the area subjected to tensile has a transversal contraction. This theory takes into account the transversal contraction factors and consequently the eigenpulsations of bars vibrations with rectangular section depend on the ratio between the bars width and thickness. This theory is experimentally verified for Dammar based composite bars reinforced with cotton, flax, silk and hemp fibers. For the considered bars, we have experimentally determined the eigen frequencies and the damping factor values.

Abstract: The selective collection of plastic, paper, glass and metal waste represents a desirable behavior in any civilized community with environmental concerns. The collection and recovery of recyclable materials is also a concern for the city of Arad, the purpose of this study being that of identifying the strengths and weaknesses of selective waste collection at the level of this urban community. Starting from the premise that responsible behavior in terms of waste and its collection is an important factor in the ecological development of a community, the present article aims to explore the local realities in this regard, to diagnose the state of things, as it is at present, in the city of Arad. We have highlighted and recorded the population’s existing mentalities and perceptions, the citizens’ expectations from the local authorities, in order to provide optimal intervention opportunities to increase control for a better management of selective collection.

Abstract: In the paper, are studied the effects of three acids (sulfuric, nitric and hydrochloric) in concentrations of 10% and 20% on the composite materials (type resins reinforced with fiberglass). These composite materials are obtained manually and lends itself to getting various containers (for water for example), but can be obtained containers for temporary storage of acids. Certain composite materials with various combinations of fiberglass with a precise number of layers can be used for temporary storage of acids as a result of experimental research made in these paper are also given.

Abstract: Polymeric bio-composites have special characteristics and use in various areas such as: automotive, aviation and aeronautic industries, civil engineering and for medical devices manufacturing. This paper presents the evaluation of impact behaviour of some types of materials suitable for orthopaedic use. As composites behave very differently at different rates of loading, static strength tests cannot be used to predict impact behaviour in the perspective of prosthetic medical devices study and manufacture. The used testing machine is Instron Dynatup Impact System with Data Acquisition and Control, model 8200, with assisted system of data acquisition and control.

Abstract: The Pelton turbines convert hydraulic energy into mechanical energy, through the Pelton runner, by using high heads and small discharges. The runner has a complex geometry, described in drawings by transversal and longitudinal sections that form continuous surfaces. The SolidWorks software was used to design two Pelton runners: the R1 runner with 21 buckets and the R2 runner with 19 buckets. The runners were made of polymeric materials through the Rapid Prototyping process, using the Objet Desktop 3D printer, which is based on the Objet PolyJet technology, with a layer thickness of 28 microns [1]. The runners were used to measure the hydrodynamic characteristics of a Pelton microturbine on a test rig. The paper aims to highlight the advantages of the Rapid Prototyping process compared to the traditional technology used to manufacture Pelton runners that are intended for experimental research.

Abstract: Polyethylene (PE) insulations have a wide applicability in the insulation of both underground pipelines and underground power cables. In this context, by coupled techniques of thermal analysis (TG/DTG+DTA) and microbiological determinations, have been studied thermooxidability and resistance to moulds action of some polyethylene sorts. Following the processing of the experimental data obtained by thermal analysis it was found that during the applied heat treatment (100 oC), in the first approx. 380 h, there is a growth of LDPE (low density polyethylene) polymerization degree by elongation of the aliphatic chains, after which the predominant process consists in the structure crosslinking. For MDPE (mean density polyethylene) samples, during the thermal treatment applied, it was found that the crosslinking degree of polyethylene (PE) increased without significant molecular weight change (with all the related consequences of increasing the weight of the tertiary and quaternary carbon atoms in the molecule). Microbiological determinations have highlighted that the resistance to filamentous fungal action of LPDE is higher than that of the investigated MDPE. It was found that after heat treatment applied (1000 h & 100 oC), both at LDPE and at MDPE, decreases the resistance to moulds action is decreased. It has also been found that moulds action resistance is substantially decreased when inoculated culture media and PE samples are exposed to an alternative electric field of 50 Hz – 6 Vrms/cm.

Abstract: This paper presents the influence of the grinding percentage on some electrical properties, when the process of injection is used in the production of technical commodities, made of polyamide 6.6 (PA 6.6), polyoxymethylene (POM) and acrylonitrile butadiene styrene (ABS), for different industries. The specimens produced had the following compositions: new material 100%, new material 80% + grinding 20%, new material 60% + grinding 40%, new material 40% + grinding 60%, new material 20% + grinding 80% and 100% grinding. The measurement of the electrical properties was carried out using the methods for the determination of relative permittivity and of the dielectric dissipation factor, with the method of zero by Schering bridge. It was found that increasing the percentage of grinding in samples, from 0% to 100%, determined a slight increase in the values of relative permittivity at all three polymers tested and the increase of measurement frequencies for acrylonitrile butadiene styrene and polyoxymethylene led to insignificant changes in the values of relative permittivity, while in the case of polyamide, increasing the measurement frequency led to a slight decrease in the values of relative permittivity. It was also found that increasing the proportion of grinding in the specimens, from 0% to 100%, determined a slight increase in the values of the dielectric dissipation factor in the case of polyamide and polyoxymethylene, while in the case of acrylonitrile butadiene styrene increasing the percentage of grinding in the samples resulted in insignificant changes. The increase in the measurement frequencies for the three tested polymers resulted in a decrease in the values of the dielectric dissipation factor.

Abstract: Extending of the welding application field by high frequency currents of the thermoplastic polymers requires the full knowledge of the physical parameters which characterize the joining process of the welded joint. Since these engineering materials are extremely sensitive to temperature variations, the present paper highlights the role of the thermal gradient in obtaining of some welded joints with high mechanical strength and free from continuity defects. Regarding this, it is demonstrated that increasing the thickness of the polyvinyl chloride films, from 0.4 to 1 mm, the heat effect in the contact area of the electrodes is kept and the welding process has a high stability. For a well-run welding process is obtained a uniform distribution of the molten material in the joint area with positive impact on the breaking force values.

Abstract: Using the reliability accelerated tests in the early stage of solar cells life cycle, by using an high level of stress, in order to highlight the one or more degradation factors, on which could be quickly acquired a series of the experimental data, leads to point out the design errors of solar cells and to predictive assessment of reliability indicators. Environmental factors influence the lifetime of a solar cell. The action of each factors determines its aging and finally its degradation as the result of the combined action of sunlight, emissions, climate change, temperature and humidity, the action of dust, the saturated air from the proximity of oceans and seas, whose actions a solar cell undergoes during normal operation. In this paper has been analysed 10 polycrystalline solar cells subjected to accelerated corrosion tests. It has been also carried out two analyses, the first a quantitative analysis by determining the values of reliability indicators and the second one was a qualitative analysis of the degradation of polycrystalline solar cells using the optical microscope.

Abstract: Obstructive sleep apnea syndrome (OSAS) in children is characterized by recurrent events of partial or complete upper airway obstruction during sleep. Functional orthopedics has been used for patients who have OSAS and craniofacial anomalies because they change the mandible posture forwards, improving the respiratory function. In present, much attention is accorded to the relationship between respiratory function and facial morphology. This study combines the cephalometric measurements and cardio-respiratory polygraphy, in order to analyze the effects of a modified functional Twin Block polymeric appliance on respiratory variables in OSAS patients. The chief complaints of the included in study patients was the crooked teeth and the teasing about their smile. Pretreatment facial photographs show labial position of anterior teeth, gummy smile, a large overjet, incompetent lips and retrognathic mandible. The patients underwent overnight cardio-respiratory polygraphic tests in the same Sleep Laboratory, before and after mandibular advancement device treatment. At the end of the orthopedic treatment phase, the beneficial result of this study was the mandible correction, the maxilla restrained, over jet decreased, improving the facial profile and reintegration of the patient in the school social environment. The education of the parents and of the small patients to recognize the symptoms of sleep apnea and to apply the available effective treatments with a positive social impact on self-esteem and which recovers the facial aesthetics and functionality is a stringent necessity.

Abstract: Maxillary obturator prostheses are dental devices used to close palatal defects created by surgical resection of different type of tumors, congenital malformation or trauma. The most popular material used for denture fabrication is the polymethyl methacrylate (PMMA). In recent years thermoplastic resins has attracted attention as a denture base material. This paper presents experimental compression and traction tests of VertexTMThermoSense from Vertex-Dental B.V. VertexTMThermoSense is a thermoplastic material based on a compounded mixture of Polyamide and pigments used in the fabrication of removable full and partial dental prostheses. Test results show that the average compressive yield strength of the samples is 60.18 MPa. The result of the tensile test showed an average of 49.4 MPa yield strength. VertexTMThermoSense has a very good average of the yield strain of 10%. The average of Young modulus is 1050 MPa.

Abstract: This paper presents the reinforcement effect of bentonite (0 – 30%) on styrene-diene block-copolymers in correlation with the biphasic morphology of these thermoplastic elastomers.

Abstract: Tooth bleaching and other cosmetic treatments (performed at home or in the dental office) are very common nowadays. The use of thermoplastic materials for the manufacturing of whitening trays should have good biomechanical properties in order to assure a good treatment outcome with a good esthetic result. The most common tray manufacturing material is an acrylic poly-resin thin foil that can be vacuum-formed in order to fit any clinical situation. The material must be inert in order to prevent harmful free radicals release form the interaction with different bleaching substances. Thermoformed trays were manufactured in our dental office and immersed in a mixed oral suspension (that also contained artificial saliva) in order to test the behavior of the material in the intraoral environment.

Abstract: The present research was made by following three directions: dissection and plastination, clinical ankle joint ligament injuries and MRI and CT examination of the cases.191 cases of ankle joint ligament injuries have been studied during two years. They were examined clinically and radiologically, using CT and MRI testing. The classification of ankle sprain was based on the number of injured ligaments. Out of the 191 cases diagnosed with ligament injuries, 92 involved the anterior talofibular ligament, 54 in the calcaneofibular ligament, 40 involved the posterior talofibular ligament and 5 involved the deltoid ligament. First degree sprain involves the injury of the anterior talofibular ligament, the second degree sprain involves the injury of the anterior talofibular ligament and of the calcaneofibular ligament, and the third degree sprain involves the damaging of anterior and posterior talofibular ligaments, as well as the calcaneofibular ligament. In this paper we have diagnosed a number of 39 first degree springs, 12 of second degree springs and 41 of third degree springs. The standard X- ray examinations have a low diagnostic rate of the ankle ligament injuries. Conventional MRI has a higher accuracy in diagnosing ankle joint collateral ligaments lesions.

Abstract: The paper presents the results of research for magnetic composites made of metallic filler from alloy Fe65Co10Ni3W2B20 and epoxy resin EPIDIAN 100. The composites studied contained less than 10% of the resin, making them dimagnetoelectrics. The structure of alloys and composites was investigated using X-ray diffraction and scanning electron microscopy and their magnetic properties using a vibration magnetometer. It has been shown that the structure and properties of the composites depend on the chemical composition of the metallic filler. And good link between components, with the proper placement of the filler in the matrix, has an impact on the quality of the composite.

Abstract: This article describes the evaluation of molecularly imprinted polymers (MIPs) obtained by wet phase inversion for facile separation of hypericins from Hypericum perforatum L. (or Saint John’s Wort, SJW). In this respect, concentrated extracts containing hypericin and pseudohypericin were used as “phyto-templates” for creating selective cavities into the pearl shaped MIPs. The obtained MIPs were characterized by infrared and by thermal analyses. Chromatographic evaluation of the MIPs was performed relative to blank samples and it was concluded that the pearls can retain selectively the hypericins from SJW extracts.

Abstract: Palpebral ptosis is a condition caused by different congenital and acquired pathologies. Seeing difficulty due to the visual field obstruction, prefrontal headaches due to chronic use of the frontalis muscle in an attempt to lift the eyelids and cosmetic deformity are the main complaints of the patients. The surgical correction of the ptosis can be challenging. According to the preoperative evaluation, the most appropriate technique should be used to maximize the postoperator result. We describe a new surgical approach for severe upper eyelids acquired ptosis consisting in reanimation of both eyelids by using the neighboring active muscle. We considered the patient a good candidate for the new surgical approach we introduce as one time operative procedure. The result was a normal palpebral fissure for both eyes. The advantage of this approach consists in performing one time surgery followed by immediate postoperative mobilization of the upper eyelids which determine the recovery of the upper lids motility by further self-control.

Abstract: There are many fixing and colouring substances largely used in the anatomy laboratories, for teaching purpose. We have injected 22 adult human hearts, removed from the cadavers belonging to the Anatomy and Embryology Department. On 6 specimens we have followed the embryologic myocardium structures for micro angio architecture studies. We used histological techniques like: haematoxylin-eosin, Van Gieson, and Masson‘s Trichrome methods. Also we have removed and dissected 14 kidneys and 16 anatomical structures of the peripheral nervous system: coeliac ganglia, aortico renal ganglia and mesenteric ganglia. The least were analyzed using specific techniques of the nervous system: Nissl method and Bielschowsky silver stain method. 8 foetuses (aged between 4 and 8 months of gestation) were dissected and also analysed. Our results were in according to the literature studies.

Abstract: Synthetic polypropylene materials are increasingly being used in surgery to repair parietal defects in perineal floor curing surgery, in genital prolapse and stress urinary incontinence. The tissue response to contact with these materials varies, and the inflammatory tissue response may be a prognostic marker of success in surgical interventions that involve contact between tissues and polypropylene materials.

Abstract: The aim of this paper was to present the method used for creating a 3D model of a fractured hemipelvis and its accuracy in reproducing dimensions and structural relationships between fractured fragments. A PolyLactic acid model of the hemipelvis was generated with the aid of the 3D printer. Using a 3D model of a complex fracture aids the orthopedic surgeon in planning the intervention and choosing the best fixation method. Patients with pelvic fractures are not usually operated immediately, which is why they can benefit from this technology.

Abstract: Ureteral stents represent one of the most utilized medical device in urology, as a minimally invasive alternative to preserve urine outflow. The ideal ureteral stent which combines long-term efficacy with a very low rate of side effects is still missing from the urologist armamentarium. The main material for ureteral stents production is polyurethane. In order to improve the side-effects and complications of polyurethane stents, special coatings were developed. The aim of this study is to evaluate short-term side-effects and complications of different polyurethane stents with or without coating used in urologic field.

Abstract: The bronchial stump fistula shown by patients undergoing adjusted pulmonary resections is an extremely severe condition affecting the prognosis of this patients. Within our study, we have used an innovative technique of closing the bronchial stump for 38 patients undergoing adjusted pulmonary resections. The suture of the bronchial stump was made through an innovative method, by practicing the suture with isolated 2.0 Prolene wires armed with patches of Polypropylene. The incidence of the bronchial stump fistula for the observed lot was of 5.26% (2 cases), smaller than the one reported in the specialty literature. In this respect, we consider that the use of Polypropylene in the techniques of closing the bronchial blunt can be beneficial.

Abstract: Mesenchymal stem cells (MSCs) are increasingly being used in regenerative medicine to repair various tissue types. This study aimed to assess changes in MSCs properties as a result of their interaction with two biomaterials in order to evaluate their in vitro compatibility. We have used two types of biomaterials, as follows: hydroxyapatite anodized titanium (HA-Ti) is used in bone reconstruction; it is hard and remains in the body, while patches of collagen combined with poly-e-caprolactone (C-PCL) are utilized in the reconstruction of soft tissue (particularly the skin); these patches resorb in the body, being only a temporary matrix that fosters and accelerates tissue formation. We have chosen to assess changes in morphology, viability and proliferation of MSCs obtained by lipoaspirate, through direct contact with the biomaterial or in eluate. MSCs properties were assessed by optical microscopy, fluorescence microscopy after acridine orange/ethidium bromide (AO/EB) staining, and the MTT assay. After result interpretation, we gained an image of the cytotoxicity phenomenon seen during the experiment and were able to assess viability of cell in contact with the biomaterials used. HA-Ti shows better interaction with cells, which preserve their viability, and does not influence MSCs growth, proliferation or morphology. In contrast, cells on C-PCL matrix become small, spherical, were detached from the plate and had lower viability percentage.

Abstract: The paper is focused on the comparison between the experimental test and numerical analysis of a composite panel wich is subject to plastic deformation. An experiment was done on a sandwich panel made from steel – extruded polystyrene – steel, wich was subjected to a static plastic deformation with help of an sferical indenter. During the test the force applied to the indenter and the vertical displacement of the steel panels were measured. The experimental values were compared with the results of numerical simulation, wich was done with help of ANSYS-Static Structural module. Important aspects of FEA, such as material idealization, contact approach between bodies, mesh size and boundary conditions, are discussed and their influence on the results are highlighted. The results of this study are vey useful for investigation of beahviour at impact of composite materials such as steel-polystyrene sandwich panels.

Abstract: In this paper, we propose an analyzis method for the dynamics of polymer chains, based on a Ricatti procedure induced by possible correlations through the compatibility of the thermal radiation-classical damped oscillator dynamics. Then, the quantification (radiation frecquency is directly proportional to the color temperature) and the erasure of one bit of information becomes a natural processes induced by the system structure itself. The theory has implications in the dynamics of biological structures (arhitecture of tumors, information on tumor growth and angiogenesis, etc.) in the form of Resonant Recognition Model.

Abstract: Patients with occupational lung diseases (OLD) may present respiratory functional impairment, exertional dyspnea and decreased exercise tolerance. These factors lead to reduced daily physical activity, social isolation, decreased quality of life (QoL) and depression. Assessment of respiratory functional status in patients with OLD in correlation with the presence of anxiety and depression and the quality of life in patients with OLD, as extrapulmonary comorbidities. In patients with diagnosed OLD, the following parameters were evaluated: pulmonary function tests (FEV1, FVC), anxiety and depression with Hospital Anxiety and Depression Scale (HADS), and QoL by St George Respiratory Questionnaire (SGRQ). 46 non-smoking patients (9 females) were included in this study: occupational asthma (10), occupational COPD (20), pneumoconiosis (16). Mean aged 58.98±11.84SD years old. Anxiety and depression were present in 35 patients (76.08%). Mean HADS score was 14.3 points±7.25SD, and a severe psychological impairment (HADS > 16) was found in 16 cases (34.8%). The highest incidence of anxiety and depression was found in COPD (85%, mean HADS score 16.05 points±8.18SD), followed by pneumoconiosis (75%, mean HADS 13.5 points±6.87SD) and OA (60%, mean HADS score 12.2 points±5.45SD). The QoL was affected in all patients, with a mean SGRQ score of 52.7 points±16.1SD; the most affected was the activity domain. In patients with OLD, extrapulmonary manifestations may be encountered, such as anxiety, depression and ultimately impaired QoL. This may indicate that treatment of these patients should be multidisciplinary, including psychosocial support.

Abstract: The study compares flexural strength of single polymer polyester composites. Composites under examination had the form of laminates differing in the content of the reinforcement phase and the type of material subject to simulated absorption of distilled water and sea water. Simulation tests of distilled water and sea water absorption for single polymer polyester composites with 5% to 20% reinforcing phase were made in accordance with the PN-EN ISO 62:2008 standard. The determination of the measure of degradation of the composites, the magnitude of the bending stress, was conducted in accordance with the PN-EN ISO:178 standard. This work is part of a research relating to the quality and recycling of single polymer composite materials. The testing part of the research is aimed to define the properties of examined materials before they are used commercially in specific products.

Abstract: Preparation epoxy based hybrid composites were involved kaolin geopolymer filler, organo-montmorillonite at 3phr by using high speed mechanical stirrer. A mechanical behaviour of neat epoxy, epoxy/organo-montmorillonite and its hybrid composites containing 1-8phr kaolin geopolymer filler was studied upon cyclic deformation (three-point flexion mode) as the temperature is varies. The analysis was determined by dynamic mechanical analysis (DMA) at frequency of 1.0Hz. The results then expressed in storage modulus (E’), loss modulus (E”) and damping factor (tan d) as function of temperature from 40 oC to 130oC. Overall results indicated that E’, E’’ and Tg increased considerably by incorporating optimum 1phr kaolin geopolymer in epoxy organo-montmorillonite hybrid composites.

Abstract: A post-mortem examination of an 1,5 years old Shar- Peis, dog was performed in order to find out the death cause. The macroscopically examination revealed a large amount of blood in the abdominal (hemoperitoneum) The liver was sampled for histopathological examination. Hematoxylin-eosin–methylene blue staining wasperformed 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 liver amiloidosis.

Abstract: The current trend in screening against cervical cancer is to improve the sensitivity of screening method and p16/Ki-67 dual-stained cytology, represents a promising approach. We performed a study to investigate the correlation between the p16/Ki-67 co-expression and HPV type on a group of patients with ASCUS and LSIL on Pap smear. On all patients, dual stain test and HPV genotyping were performed. In the group of patients with positive dual stain p16/ki-67 test, the number of patients with HPV type 16 was significantly higher than the number of patients with any other type of HPV. Also, all patients with CIN3 or above (cervical cancer) were positive for p16/Ki-67. Our study shows the potential use of those two tests to identify patients with high risk for severe dysplasia.

Abstract: Postoperative edema and lean body mass may contribute to functional outcome in frailty hip fracture patients. Advances in body mass determination have produced consistent results with A-mode ultrasound. We therefore aimed to determine the utility of A-mode ultrasound in analyzing postoperative limb edema in patients receiving treatment for proximal femur fractures. 4 males and 6 females, with an average age of 74.3 years were included. 4 had fractures of the femoral neck treated by hemiarthroplasty and the rest had extracapsular fractures which were stabilized with short intramedullary nails. Measurements were done using a commercially available A-mode 2.5MHz transducer on the thighs approximately 15 cm proximal to the patella. Comparison showed significant difference between the operated and contralateral thigh circumference (P=0.001) as well as muscle layer thickness differences between femoral neck patients and those with fractures of the trochanteric region (P=0.016). There was no correlation between the A-mode ultrasound determined superficial layer difference and entire layer difference (R2=0.037; P=0.59). However, there was linear correlation between the A-mode ultrasound determined entire layer difference and limb circumference difference, (R2=0.414; P=0.044). Postoperative thigh edema is present in all surgically treated patients for proximal femur fractures. A-mode ultrasound might be a reliable tool to examine adipose and muscle layers separately in the immediate postoperative period. There may be a difference in edema distribution between femoral neck and peritrochanteric fractures but larger samples are required.

Abstract: The teeth are found in the alveolar processes of both the upper and lower jaw and they form the two maxillary and mandibular dental arches, the various relations of which support the performance of the dental apparatus functions, one of the most important of which is mastication. These relations are also known as interocclusal relations, among which the moments in which the dento-dental contacts (occlusal relations) play an important role. Maximum intercuspation (MI) is the most frequent mandibulo-cranial functional position with dento-dental contact. The vast majority of functional food incision and mastication cycles end in MI. The highest number of dento-dental contacts, and the largest possible stability and surface of these contacts are also achieved in MI. Given the relative easiness of determination, recording and transfer of the MI position, it is used in many clinical situations to report the models of the two arches. The interocclusal recording materials used in our study were seven silicones, six of which with addition reaction, five with special destination for interocclusal relation determination and a putty-like silicone normally used for dental arch impression – Elite HD and one condensation silicone used for impressions. The reason for choosing the last two materials was the fact that some practitioners frequently use putty-like impression silicone to determine interocclusal relations. According to the findings of the measurements shown in table 1, further to the initial impression process, at the time T0, satisfactory results were obtained both for addition silicones and for condensation silicones, Registrado X-tra being the only recording material which exhibited major deviation from the standard dimension (3 mm). As for the Optosil condensation silicone, we noted a significant increase of the thickness of the material starting with the first hour after impression and reaching considerable values on the 5th day, which were 0.3 mm higher than the standard value. Rigid addition silicones have the lowest dimensional stability; putty-like silicones are frequently used to record interocclusal relations for fixed prosthetics, which is wrong since they grow rapidly and this impedes on the space between the treated tooth and the opposite tooth, the result being a high restoration, which may determine premature contacts. Except for Optosil, which exhibited a continuous increase, most materials may be used to mount models in the simulator after 24 h.

Abstract: The liver segmentation is mainly determined by the intraparenchymatous distribution of the vascular and ductal hepatic elements; from this, the hepatic portal vein (HPV), is the most important afferent element. The lateral branches (LBrs) are serving left lateral division (LLD) of the liver and present a moderate morphological variability. On a total of 160 pieces of liver corrosion casts, one examined the intraparenchymal distribution of portal LBrs and the segmentation of LLD. Regarding the intraparenchymal distribution of the portal branches in the LLD of the liver, we showed two distinct morphological types: Type I (89.375% of cases) in which from the ombilical part of the left branch arise two LBrs; Type II (10.25% of cases) in which from the ombilical part of the left branch arise three LBrs. Knowledge of these morphological types of portal LBrs is important for clinical and surgical practice.

Abstract: The paper presents the results of rheological tests for three commercial acrylic bone cements currently used in total hip replacement . Moreover, twelve experimental formulations of acrylic bone cements were realized, by partially replacing the methyl methacrylate (MMA) from the classical liquid monomer phase with a new monomer and their rheological properties were evaluated and compared with the commercial bone cements. Thus, the efficacy of acrylic bone cements as anchoring materials as well as their handling and curing properties were estimated. The new formulations exhibited higher elasticity, lower dynamic moduli and clear shear-thinning behavior proving to be potential replacements for classical acrylic based bone cements.

Abstract: Orthodontic therapy using aligners is a modern treatment option among adult patients. In order to have an optimal control of the orthodontic resuslts, there is a need for knowing the deformation values that can appear in each type of aligner, the optimal thickness values of the appliances and the needed number of aligners for each case. The deformation values for a 0.2 mm repositioned lower central incisor were measured with the use of some strain gauges applied at this level, after a manual set-up was manufactured. Different orthodontic forces were applied on each aligner in order to compare the deformation value during the dental correction. The thickness values of the aligners that were used for this study were 0.625 mm, 0.75 mm and 1 mm. The 0.625 mm aligner had the lowest deformation value dueto a high elasticity of the material.

Abstract: The aims of the study were to characterise the resin-resin interface when a universal bonding agent (UBA) was used in two different strategies in direct composite repair and to evaluate the bonding capacity of UBA by microleakage assessment. In study groups a micro-filled hybrid and a nano-filled hybrid composite resins were aged in order to simulate an old restorations. As a repair material was chosen the same micro-filled hybrid composite resin that was used as an old restoration. UBA was applied in etch-and-rinse and self-etch strategies and was used as an intermediate layer in repair procedure. After the repair the samples were aged again. In control groups were included non-aged, repaired composite resins samples. The resin-resin interface was characterised on SEM images and the microleakage at the interface was evaluated by dye penetration assessment. Universal bonding agent used in direct composite resins repair showed a very good adaptation to non-aged micro-filled hybrid and nano-filled hybrid composite resins. Aging by saliva storage of repaired composite resins leaded to an enlargement of resin-resin junction and a increased microleakage irrespective of the strategy (etch-and-rinse or self -etch) used for bonding agent application. Etch-and-rinse strategy for universal bonging agent application determined a better interface bonding when compared to self –etch strategy.

Abstract: Plastic compounds have been used for several decades to generate anatomical constructs for the training of new surgeons and medical students alike. The present study seeks to highlight the advantages and disadvantages of two different plastic compounds (Technovit 7143 and Epoxi BIODURÒE12) used to create corrosion casts of the vascular branching patterns in free muscle flaps. Porcine latissimus dorsi muscle free flaps were used in this study to create corrosion casts of their vascular branching tree by injecting the two different plastic compound into the main arterial supply. The casts generated by Epoxy BIODURÒ E12 have superior qualities compared to the casts injected with Technovit 7143, because the injection process is smoother at all branching levels, without dilation, strictures or intramuscular extravasation of the injectable plastic compound. The corrosion casts resulted from injecting Epoxy BIODURÒ E12 exhibit better elasticity and better resistance to mechanical handling compared to the ones injected with Technovit 7143.

Abstract: Developing biomaterials with optimal loading properties and controlled release of drugs is a priority of medical research. Clinoptilolite is a natural zeolite used in various industrial processes. Its texture and structure recommend its use as a biocompatible matrix for the development of modified release drug delivery systems. The present study aims to develop and characterize modified-release systems based on bexarotene loaded clinoptilolite. Bexarotene is a retinoid that is used as an anticancer agent in the topical treatment of cutaneous T-cell lymphoma. By adding bexarotene to these systems, skin delivered antineoplastic therapy with bexarotene can be improved. Clinoptilolite was obtained by purifying the volcanic tuffs from Mirsid quarry, Salaj Romania. After thermal and chemical purification, two monoionic forms of clinoptilolite were obtained. They were labeled as Na-CLI and H-CLI, respectively. Their texture and structure were characterized by specific methods. Subsequently, these forms of clinoptilolite were used as hosts for bexarotene loading by wet impregnation. The obtained results showed that the two modified-release systems Bxt@Na and Bxt@H, respectively, have no incompatibilities and provide prolonged release of the drug.

Abstract: Grape marc, also known as grape pomace, is one of the most investigated bio-wastes derived mainly from grape skin and seeds, which is produced as a by-product of winemaking on the million-ton scale annually. Presently, the most important high-value use of grape pomace is in the production of oenological tannins, widely-used additives in the food and beverage industry. This article studies the possible use of grape waste in the plastic industry, as request of the consumer for green plastics with regards to environmental impact, and in the case of packaging, to improve the shelf-life and safety of the products contained. 4 white grape varieties and 4 red grape varieties (most cultivated grape varieties in Romania) were taken into study, processed using different technological methods and the spent material (grape skins and seeds) were analysed regarding their total phenolic compounds and total tannins.

Abstract: The spectroscopic and photochemical properties of polyurethane coumarine (PUC) in solid state were investigated at room temperature under once-photon excitation. One photon induced photocycloaddition of PUC was investigated and the AFM and spectroscopic FTIR analysis confirmed dimer formation. The AFM analysis shows that the fotodimerization process occurs at the surface of polymer films. The polyurethane coumarine film on CaF2 unirradiated and irradiated underline both the fotodimerization of the polymer films as well as the photoclevage of the polyurethane coumarin.

Abstract: In this paper it will be presented the deformations analysis using the finite element analysing method, for an armchair seat redesigned from an wooden original model, into a polyurethane more compact structure. In order to perform the testing required, a 3D PU design was made after the wooden model. This new design was made in such way which will enhance the productivity, to be more compact, more lightweight and also more resistant than the original design.

Abstract: In the paper are presented the experimental researches made in order to obtain a new titanium alloy - Ti15Mo5W used for medical applications with improved mechanical characteristics and modulus of elasticity. In this regard Ti15Mo with addition of W alloy was designed with the intention of obtaining b-Ti phase stability. For this, we studied the influence of: the bond order, energy level of metal d-orbital, ratio of valence electrons/atom and influence of the addition of W. After designing the alloy compositions and setting the parameters, the Ti15Mo5W composition was chosen to run the experiments. The experimental Ti15Mo5W alloy was obtained by vacuum arc remelting technique using Ti, Mo and W high purity metals. The alloy was characterized by SEM, EDS and tested for Vickers hardness and compression. The microstructural characterization of the alloy proved to be homogeneous, and the mechanical characterization highlighted the obtaining of an alloy with a low elasticity modulus of about 30 GPa and an average hardness of 320 HV.