bluuebunny/crossref_metadata_2025 huggingface dataset:
Polylactic Acid/Cellulose Fibres Based Composites for Food Packaging Applications
Authors: Popa Elisabeta Elena , Rapa Maria , Popa Ovidiu , Mustatea Gabriel , Popa Vlad Ioan , Mitelut Amalia Carmen , Popa Mona Elena
Published: January 2020

PLA-based composites containing CF in the range 0 to 10 wt. % were prepared by melt mixing technique. The prepared composites were investigated in terms of processability, chemical structure (by Attenuated total reflectance - Fourier Transform Infrared - ATR-FT-IR analysis), thermal (Differential Scanning Calorimetry - DSC), optical properties (using UV-Vis spectrometry), barrier and migration in distilled water. Also, the behaviour of PLA based composites at sterilization was performed by examination the changes in their chemical structure. This study shows the feasibility of improving of PLA properties by using cellulose fibres, designed for flexible food packaging.
Experimental Characterisation of Hyperelastic Materials for Use in a Passive-Adaptive Membrane on MAVs Wing
Authors: Pahonie Radu Calin , Larco Ciprian , Andres Mihai Mihaila , Nastasescu Vasile , Barbu Cristian , Costuleanu carmen Luiza
Published: January 2020

The paper focuses on the experimental characterization of hyperelastic of the shelf materials in an effort to implement a membrane skin on a low speed asymmetric wing, in order to assess the benefits of flexible lift surfaces. To better determine the best strain energy function definition for the membrane materials, the most notable hyperelastic constitutive models were used together with experimental uniaxial and equiaxial planar tests. For the experimental equi-biaxial test a special loading device was designed and built in the laboratory. The strain measurements for the experimental tests were conducted using digital image correlation, for increased data precision. From the available constitutive material models taken into account, the best for this application proves to be the Yeoh model, as the experimental strain-stress data has a close match for small as well as large strain values. Numerical simulations using finite elements and the Ansys software were performed to predict the materials behavior.
Composite Solutions for Deck Catamarans
Authors: Beznea Elena Felicia , Chirica Ionel , Presura Adrian , Iacob Ionel
Published: January 2020

The paper is treating the strength analysis of the main deck structure of an inland navigation catamaran for 30 passengers. The main deck should have high stiffness and high strength to resist to external loading and endure high stresses from combined bending and torsion loads. Different materials for sandwich structure of the deck have been analysed by using the Finite Element Method in order to determine the solution which accomplish better designing criteria regarding allowable stress and deformations and total weight.
T-Tube Conformational Stent with Aspiration Used in Dacryocystorhinostomy
Authors: Hainarosie Razvan , Rusescu Andreea , Pietrosanu Catalina , Ionita Irina , Hainarosie Mura , Stefanescu Dragos Cristian , Zainea Viorel , Cherecheanu Alina Popa
Published: January 2020

The development and increase use of the endoscopic techniques in endonasal surgery has encouraged the practice of endoscopic dacryocystorhinostomy as a trustworthy alternative to external dacryocystorhinostomy. The purpose of the present paper is to provide another insight into transnasal endoscopic dacryocystorhinostomy by proposing the fitting, at the end of the intervention, of a conformational stent model with aspiration made out of medical silicone similar to a Montgomery tube.
The Influence of ZnO/TiO2 Nanohybrid Blending on the Ultrafiltration Polysulfone Membranes
Authors: Pintilie Stefan Catalin , Tiron Laurentia Geanina , Lazar Andreea Liliana , Vlad Maria , Birsan Iulian Gabriel , Balta Stefan
Published: January 2020

In recent years, the inorganic nanoparticles played an important role in the membrane technology due to their special properties, most notably being the hydrophilicity/hydrophobicity modification of the active surface of the membrane. In this paper, the polymer used for membrane manufacturing was polysulfone (PSf) via phase-inversion method. The composite PSf membranes were prepared by blending zinc oxide (ZnO), titanium dioxide (TiO2) nanoparticles and ZnO/TiO2 nanohybrid with three concentrations. Retention of Congo red dye, distilled water permeability, relative flux and relative flux reduction were tested in order to study the effects of the nanoparticles in the membrane matrix. SEM, EDX, porosity, roughness, contact angle, tensile strength and elongation measurement were conducted in this article, also. Compared with control PSf, ZnO/PSf and TiO2/PSf membranes, the experimental results indicated that the ZnO/TiO2/PSf nanohybrid membrane presents the best overall properties, including permeability, retention, and antifouling ability. ZnO/TiO2/PSf membrane exhibits a percentage increase in permeability of 254% and retention of 64.58 % relative to that of the control PSf membrane.
Biophysical Assessment and Impact of Catalyst on the Properties of Polyurethane Drug Carriers
Authors: Susan Razvan , Pana Ramona , Sas Ioana Tuta , Borcan Florin , Ardelean Elena , Enache Alexandra , Pinzaru Iulia
Published: January 2020

The metal complexes and amine compounds are the most frequent categories of catalysts used in polyurethanes synthesis. Unfortunately, all auxiliary substances added to a synthesis increase the toxicological risk of final products used in a therapy. In the present study, polyether-urethane (PU) microstructures with and without catalyst were obtained. These structures were characterized by the measurement of samples� pH, of their size and stability, were obtained and the skin irritation potential. The results show that samples with a neutral pH, PU microstructures with sizes between 120 and 165 nm and with a medium stability. It was found that the microstructures from syntheses with catalyst present increased values of skin irritation.
Comparative Study Between Tissues Induced Immunohistochemical Changes of Thread Granulomas and Textile Allografts
Authors: Chicea Radu , Chicea Anca Lucia , Mihetiu Alin , Tantar Cristian Alexandru , Mitariu Mihaela Maria Cernusca , Mitariu Sebastian Ioan Cernusca , Roman Corina , Comaneanu Raluca Monica , Bratu Dan , Manea Marinela Minodora
Published: January 2020

Since the time of their introduction into medical practice, biomesh were criticized for their lack of tissue integration and the rejection due to the organism reaction for an element that is not autologous. The mechanisms by which these changes of contact between the tissue and the foreign material were produced were initially incompletely understood, but over time the involvement of the immune system mediated by the cellular or humoral local inflammatory reaction was established.
Effects of Materials Based on Acrylic Resines on Inflammatory Markers IL-8 and TGFb1 in Gingival Crevicular Fluid
Authors: Vlad Cristian Sebastian , Dumitrascu Victor , Vlad Daliborca Cristina , Popescu Roxana , Cimporescu Adinela , Flangea Corina , Cheveresan Adelina , Sipos Simona , Barac Beatrice , Malita Ioana
Published: January 2020

Materials based on acrylic resins are commonly used in dental practice. These are obtained through various technologies, which determine the chemical, physical and biological properties of the final product, which can influence the inflammatory processes in the periodontal tissue. To evaluate the effects of these materials, we identified the concentrations of TGFb1 and IL8 in crevicular fluid in 23 patients with temporary dentures made of polymethyl methacrylate by two polymerization methods: (1) a product processed immediately prior to application, wherein the polymerization of the material occurs in the oral cavity; and (2) a product processed in the dental laboratory from a prepolymerized block (block-type PMMA), and applied directly into the patient�s mouth. The results of our study revealed a significant correlation between the IL-8 inflammation marker and the clinical parameters in the periodontal tissue exposed to the polymerization of the material in the oral cavity.
Dynamic Membranes on Polysulfone Support for Fuel Cells
Authors: Segarceanu Mircea , Miron Alexandra Raluca , Tanczos Szidonia Katalin , Rikabi Abbas Abdul Kadhim Klaif , Nafliu Ion Marius , Vaireanu Danut Ionel
Published: January 2020

In the present paper, the authors dealt with the synthesis and characterization of a new type of dynamic membrane with polysulfone matrix and ionic polymer electrolyte: polysulfone-sulfonated polyetherether-sulfone (PSf-SPEEK). The PSf-SPEEK composite membranes were formed by ultrafiltration of SPEEK gel on the polysulfone matrix in a CELFA System installation. The thickness of the PSf porous layer for the different membranes can be between 50 and 120 mm. The variation of SPEEK active layer�s thickness is dependent both on the concentration of the SPEEK solution in the feed, and on the velocity of the surface flow. The sulfonated polymer (SPEEK) superficial layer ranges from 35 to 75 nm, being thicker at low flow rates having a slight increasing related to the increase of the SPEEK concentration. Increasing the polymer concentration, from 0.5 to 2.5%, used in the feed solution leads to a doubling of the conductivity and a tripling of the ion exchange capacity. The maximum conductivity of the PSf-SPEEK dynamic composite membranes is 0.234 S/cm and the ion exchange capacity is 1.682 meq/g.
Bioadhesives Used in Cardiovascular Surgery
Authors: Moldovan Horatiu , Gheorghita Daniela , Antoniac Iulian , Fiori Fabrizio , Mohan Aurel , Costache Victor
Published: January 2020

Bioadhesives Used in Cardiovascular Surgery The use of surgical adjuncts allowing the reinforcement of the tissues and the performance of safe sutures and repairs become a mandatory approach. Two different kinds of adjunct emerged: polytetrafluoroethylene (PTFE) felt bands and pledgets and on the other hand, surgical adhesives. The aim of the paper is to describe the advantages and the disadvantages of the available surgical adhesives considered most useful in major cardiovascular surgery.
Reaction of a Sandwich Type Structure to Static Stress Under the Action of the Snow
Authors: Baroiu Nicusor , Beznea Elena Felicia , Chirica Ionel , Iacob Ionel
Published: January 2020

Structural elements of special industrial constructions can be often subjected to time variable stresses. One of the main stress is the snow action, which is considered to be one of the most severe tests. In the study, the static snow action on a tank cover from a pickling plant on the ArcelorMittal Galaţi platform is analysed. The material structure of the cover is sandwich type with skins made of steel /layered composite and core made of polystyrene foam. The purpose is to determine, by FEM analysis, the deformation mode and the stress condition of the cover under the action of load, for two models of sandwich type structures, steel-polystyrene-steel, respectively composite-polystyrene-composite, with different faces thicknesses and cores. Panels are applied simulative a load of snow of different thickness, the distribution of snow on the surface of the panels being considered uniform in order to determine an optimum combination of faces and core thickness as well weight and economic cost too. Numerical analysis models with finite elements of SHELL 3L sandwich type structures are used.
Minimally Invasive Dental Treatment Using Composites and Ceramics in GERD Diagnoses Patients
Authors: Picos Andrei , Rachisan Andreea L. , Dadarlat Alexandra
Published: January 2020

Specialty literature demonstrates the direct link between gastro-esophageal reflux diseases (GERD) and dental errosion (DE). Patients diagnosed with GERD often shown dental tissue loss in the enamel and dentine, somentimes going as far as opening the pulp chamber. Modern minimal invasive treatments make use of the current performance of cements and prosthetic materials (composites and ceramics) to conserve healthy enamel and dentine, in comparison to classic reconstruction methods.
Influence of Technological Parameters on the Dimension of GEAR Parts Generated with PLA Matherial by FDM 3D Printing
Authors: Vasilescu Mircea Dorin , Fleser Traian
Published: January 2020

The purpose of this research is to establish the technology of 3D printable production on the principle of FDM of gears made of PLA, ABS and PETG mainly. In the paper we present first the dimensional generation and specific aspects that need to be considered to produce gears with internal or external teeth of the cylindrical type with vertical or inclined teeth. Generating the gears appeared as a necessity for the reconditioning of the components of the processing machines and of the electric machines made both in the process of elaboration of the bachelor�s and the laboratory works, with reduced energy resource consumption and low pollution as low as possible. After the construction, we past to identify the dimension that have implications for both mechanical and kinematic resistance to achieve a product with good cinematic and functional characteristics. After that are made an analysis of the layers generated, both from the computer simulation and from the point of view of the analysis of layers physically generated on a gear tooth with external teeth.
Functional Surfaces Modified with Gelatin and TIO2 Nanoparticles
Authors: Muntenita Cristian , Circiumaru Adrian , Bria Vasile , Bichescu Cezar Ionut , Graur Iulia
Published: January 2020

The paper presents the obtaining of zinc and zinc composite coatings using electrochemical TiO2 nanoparticles as well as the determination of the influence of gelatin used as an additive on electrically co-deposited layers. The obtained coatings were studied at the electronic scanning microscope (SEM) for microstructure observation. A distinction was made between the pure zinc electro-deposed layer and the influence of nano-TiO2 on the morphology of zinc nanocomposite layers Zn/nano-TiO2, as well as the determination of the degree of inclusion of nano particles of TiO2 into the zinc matrix. It was confirmed that with the introduction of nano-TiO2, both the roughness of the electro-deposed layer and the micro hardness of the electro-deposed layer significantly increased compared to the micro hardness of the pure zinc electro-deposed layers confirming the existence and beneficial effects of nano-TiO2 in electro-co-deposed nano-composite layers.
Comparative Study of Tensile Behaviour for Layered Polymeric Composite Materials
Authors: Marinescu Marinela , Butu Larisa , Borda Claudia , Arsene Delicia , Butu Mihai
Published: January 2020

In this paper we present a comparative study on tensile failure behavior of polymer stiffened composite shell structures, using infrared thermography and finite element analysis through the ABAQUS 6.13 program. The establishment of the distortion of some rectangular shaped specimens was followed. In these specimens a hole with a diameter of 15 mm was applied centrally. By means of infrared thermography, was studied experimentally the variation of the deformations over time, depending on the stress force and the evolution of the thermal field in the crack area. Simulation models of failure behavior have been performed, which have been validated by experimental results.
Simulation of Mechanical Behaviour in Milling and Polishing of Dental Polymeric (resin) Composites
Authors: Voicu Gheorghe , Constantin Gabriel Alexandru , Saracin Alexandru
Published: January 2020

Dental resin composites have a wide applicability in the dental field. They exhibit their own chemical composition that imparts certain physico-mechanical properties. The machining of the pieces of these composites must be sufficiently light, without affecting their strength. For processing these parts, respectively of the dental work, is used or carbide burs, or diamond burs, depending on the mechanical strength of the composite. To determine composite behaviour under action of the conical finishers was simulated their behaviour in specific simulation programs. As a result, stress concentrators may appear from the first processing which may affect the later resistance of the piece or dental work.
The Most Significant Influences of Decontamination Mixtures Containing Chlorinating and Oxidizing Agents on Barrier Materials Formed by Isobutylene-Isoprene Rubber
Authors: Otrisal Pavel , Melicharik Zdenek , Svorc Lubomir , Oancea Romana , Barsan Vlad
Published: January 2020

The influences of hypochlorite DM with oil ingredient and without it, which is introduced into the armament not only by the Czech Armed Forces Chemical Corps, but also by the chemical services specialists of the Czech Republic Fire Rescue Service, on a substrate consisting of a barrier material based on isobutylene-isoprene rubber (butyl rubber) were presented in this paper. Based on the repeated exposure of the substrate formed by the barrier layer material selected by this decontamination mixture and its subsequent rinsing, a change of the breakthrough time has been studied using the MIKROTEST method employing the chemical warfare agent of sulfur mustard and Congo red as a detecting agent.
Hemoperitoneum from Ruptured Uterine Tumor Invading Ileal Mesentery and Mesosigmoid Case report and literature review
Authors: Bacalbasa Nicolae , Cirlan Cassius , Sas Ioan , Balescu Irina , Dimitriu Mihai , Marcu Madalina , Moldovan Mihaela , Pirici Daniel , Motoc Andrei Gheorghe Marius , Navolan Dan Bogdan
Published: January 2020

Uterine sarcomas are rare but very aggressive gynecologic malignancies. The most frequent signs and symptoms at the moment of diagnosis include abnormal uterine bleeding or diffuse abdomino-pelvic pains while acute abdomen by uterine rupture is an uncommon situation. We present the case of a 72 year old patient who presented in emergency for diffuse abdominal pain and hypotension. An emergency laparotomy was performed and a ruptured uterine tumor with small bowel and sigmoidian serosal invasion and intra-peritoneal bleeding was found. The tumor was resected en bloc with total hysterectomy, bilateral adnexectomy, segmental enterectomy and sigmoidectomy, pelvic and para-aortic lymph node dissection. The histopathological and immunohistochemistry examination revealed a poorly differentiated sarcoma. Although it is a rare condition, a uterine sarcoma can rupture and cause hemoperitoneum; emergency surgery while respecting oncologic principles of complete resection is mandatory.
Aspects Regarding Ageing of Compounds Based on Natural Rubber and Plasticized Starch
Authors: Stelescu Maria Daniela , Manaila Elena , Craciun Gabriela , Georgescu Mihai
Published: January 2020

This paper presents a study on the behaviour of composites based on natural rubber and plasticized starch after aging under temperate climate conditions. Natural rubber blends containing different amounts of glycerine-plasticized starch as biodegradable filler were made. Analysis of samples after being kept for 1 year in temperate weather conditions shows a change in the surface of vulcanizates due to the influence of atmospheric factors. Surface oxidation and degradation was highlighted by: FTIR analysis (appearance of -OH, -COOH groups, etc.), SEM microscopy (appearance of cracks on the surface), immersion in water. The degradation of the materials is also highlighted by the decrease of the physical-mechanical properties, the gel fraction and crosslinking degree. The best aging behaviour was observed in the mixture containing a low amount of biodegradable starch and the worst behaviour was that of the control starch-free mixture.
Multivariate Assessment of Marginal Fit of Three Types of Dental Crowns Using Three Scanning Systems for CAD-CAM Technology - in vitro Pilot Study
Authors: Buduru Smaranda , Mesaros Anca , Culcitchi Cristian , Moldovan Marioara , Prodan Doina , Szuhanek Camelia
Published: January 2020

The objective of this in-vitro study was to compare if there are any differences in the marginal fit of crowns fabricated by CAD/CAM technique. We used three different types of materials (two types of polymethylmetacrylate (PMMA) provided by two different manufacturers and one type of hybrid ceramic) and three different types of impressions: intraoral scanning, model scanning and conventional impression scanning. The crowns were subsequently measured with an electronic microscope at 1000X. Our results showed better results for the hybrid ceramic. The differences between the PMMA were not significant. There were no statistic differences with the ANOVA analysis between the scanning methods. Best combination in terms of marginal fit was found with hybrid ceramic and intraoral scanning.
Clinical Use of a New Polymer in Complete Dentures Fabrication I
Authors: Bosinceanu Dana Gabriela , Sandu Ioan Gabriel , Bosinceanu Dan Nicolae , Martu Ioana , Surlari Zinovia , Forna Norina Consuela
Published: January 2020

Because cyancobalamin deficiency is commonly treated with parenteral adminstration, the present study aims to make a comparison between the effectiveness of parenteral vitamin B12 treatment and the effectiveness of local treatment achieved by complete dentures improved by crosslinked polymerization using as template vitamin B12 (cyanocobalamin).
New Results Regarding Cavitation Behavior of Polymers Modified with Anorganic Substances Coated on Bronze Surfaces
Authors: Micu Lavinia Madalina , Lazar Iosif , Circiumaru Adrian , Bordeasu Ilare , Pirvulescu Liviu Daniel , Hluscu mihai
Published: January 2020

Due to mechanical resistance characteristics, chemical corrosion and abrasive erosion resistance, the polymers are more widely used in equipments and installations that are exploited in different fluid hydrodynamic conditions. Among these applications there is the protection of surfaces of hydromechanic organs stressed by cavitation, like in hydraulic machines rotors and valves. Consequently, the research aimes the extension of using these and protection of other components surfacess hardly streesed by cavitation. The research in this paper points toward the behavior of modified polymer layer, coated on surfaces of bronze used in casting the propellers of maritim and river ships. The tests were performed in standard piezoceramic crystal vibrating equipment within Cavitation Laboratory of Politehnica University of Timisoara. The damaging intensity of equipment is much greater than any cavitational vortex, created by ship propeller, hydraulic turbine or centrifugal pump. The obtained results, compared to both recorded on uncovered surfaces with polymer layer and recorded on surfaces covered with HVOF composite materials layers, show an increased resistance that implies the increased exploiting duration of those surfaces.
Experimental Study of Sintered Friction Material with Coconut Fiber for Brake Pads
Authors: Bretotean Camelia Pinca , Craciun Andrei Lucian , Josan Ana , Ardelean Erika
Published: January 2020

The paper presents the laboratory experiments and the results obtained regarding the production and characterization of composite materials with coconut fiber for the manufacture of brake pads for small vehicles and medium performances. The experimental research of composite material with organic components determined the influence of some material factors and parameters of the sintering regime on the physico-mechanical characteristics of the tested samples. Knowledge of these characteristics offers the possibility of pertinent appraisals regarding the behaviour of the composite materials intended for used in brake pads applications. Materials with the best features will be selected to determine the functional characteristics of friction and wear.
On the Fragmentation of Explosively-driven Plastic/steel Layered Cylinders
Authors: Trana Eugen , Bucur Florina , Rotariu Adrian N.
Published: January 2020

While over the past century fairly extensive work has been carried out on explosively-driven metallic envelope fragmentation, as the development of explosive materials and warhead configurations continued, the issue under consideration is still topical. The current paper aims to investigate the fragmentation characteristics of explosively-driven steel cylinders when double layer envelopes are used. Mott�s approach was modified in order to account for such particular configuration (layered envelope). Several tests in a simplified type procedure were performed aiming to confirm the theoretical approach.
Assessment of Paint Layers Quality 3. Analysis by SEM-EDAX and XRF techniques of the paint layers applied on a railway bridge
Authors: Lingvay Iosif , Bors Adriana Mariana , Marinescu Virgil , Mitrea Sorina , Varga Emese
Published: January 2020

In order to identify the premature biodegradation causes of paint applied in 2013 on a railway bridge, top coat layers applied have been investigated by XRF and SEM-EDAX techniques after 32 years, corresponding to periods of operation under identical climatic conditions of 4.5 years and 3.5 years respectively. By analysis of the experimental results obtained, it has been found that by using suitable painting materials (titanium content of about 7.5 % - TiO2 for UV protection) an exploitation period of more than 30 years could be obtained. Low-carbon (low polymer) and titanium dyeing materials with significant content of soluble salts have a low durability and anticorrosive protection capability. They degrade relatively fast both by top coat degradation and by intense increases of biofouling.
Impact of Flexible Polyurethane Foam Cocoon on Premature Babies of Mothers with Pathologic Pregnancies
Authors: Noditi Georgeta , Noditi George , Iacob Daniela , Anastasiu Doru , Anastasiu diana , Gluhovschi Adrian
Published: January 2020

Proper positioning of premature babies resulting from different maternal chronic conditions before pregnancy and hypertension induced during pregnancy can promote normal balanced development with maximizing the sleeping conditions and minimizing the gastric reflux. We conducted a retrospective study on data from Bega Clinics - Obstetrics and Gynecology and Neonatology for 2012-2013 about premature babies of mothers with pathologic pregnancies. Part of the newborns was positioned in a flexible polyurethane foam cocoon and clinical observations on sleeping states and the presence of gastric reflux were noted. In our study, 453 (10.5%) cases of women with different pathological conditions out of 4,312 cases were encountered. Most of them (48%) had a diagnosis of chronic hypertension, followed by chronic renal diseases (34%). Hypertension developed during pregnancy for both years, happened in 340 (7.88%) cases. Severe forms of hypertension were noted in 57.05% of them. Incidence of preterm birth babies was 11.22% (484 cases), of which 12 cases (8.67%) resulted from pregnancies with different forms of hypertension. Clinical observations stated that sleeping quietly and awake and quiet have increased the most when compared with babies positioned in the cocoon (44 babies) compared with babies (45) out of cocoons. Only 8 (18.2%) babies positioned in the cocoon experienced gastric reflux comparatively with 41 babies that were positioned in regular conditions.
Fatigue Behavior of Two Acrylic Denture Base Resins
Authors: Dumitru Catalin , Cernescu Anghel , Eremici Ivana , Bortun Cristina Maria , Achiriloaiei Daniel
Published: January 2020

Acrylic resins based on polymetyl metacrylate are used in dental prosthetics as base for dentures. One of the major failure causes of dentures is the fatigue damage of the acrylic resins. These materials, in addition to mechanical behavior, also present a high risk of structural defects (voids, micro-cracks, residual monomer) that can significantly affect the fatigue behavior. In this paper, two commercial acrylic resins have been experimentally analyzed in terms of mechanical and fatigue behavior. Tensile constant amplitude fatigue tests with stress ratio R = 0 and frequency of 2 Hz have been carried out on samples of the two acrylic resins, prepared according to the manufacturer�s recommendations. The results revealed, besides the brittle fracture character, a similar fatigue behavior following a Weibull distribution. Also, through statistical processing of the results, the fatigue curve equations of the two analyzed materials were estimated for different levels of confidence.
Operational Procedures in the Theory of the Drug Release from Chitosan Hydrogels
Authors: Craciun Anda Mihaela , Serban Georgiana , Crumpei Iulia , Agop Maricel , Cioca Gabriela
Published: January 2020

We build a theoretical model based on a generalization of harmonic applications of Misner-type. It results a sine-Gordon type fractal differential equation whose elliptical solutions can describe, through a convenient choice of fractal dynamic constants, various modes of drug release. Thus, the entire class of empirical models (Higuchi, Korsmeyer-Peppas, Peppas-Sahlin) describing the drug release processes can be dispensed with.
Negative Pressure Wound Therapy Using Polyurethane Foam in a Patient with Necrotizing Fasciitis
Authors: Avino Adelaida , Jecan Cristian Radu , Cozma Cristina Nicoleta , Stroescu Andra Elena Balcangiu , Balan Daniela Gabriela , Ionescu Dorin , Mihai Andrada , Tanase Mihaela , Raducu Laura
Published: January 2020

Negative pressure wound therapy is one of the newest methods of treatment used in wound healing. An important role of the system has a foam dressing that connects the wound with the vacuum. In general the sponge used in vacuum assisted therapies is made of polyurethane foam. We present the case of a 51-year-old male patient with a history of deep vein thrombosis (known for about 3 years) diagnosed with necrotizing fasciitis (NF). In this patient, after each step of the surgical treatment (large debridement and skin grafting) negative pressure wound therapy using polyurethane foam was used.
Flash-Free Orthodontic Adhesive System Bonded on CAD/CAM Produced Resin Restorations
Authors: Golban Denisa Maria , Negru Radu , Szuhanek Camelia , Negrutiu Meda Lavinia , Marsavina Liviu , Duma Virgil Florin , Sinescu Cosmin , Porojan Liliana
Published: January 2020

Flash-Free Orthodontic Adhesive System represents the latest technology in the field of orthodontics. In the present study the bonding technique is applied on CAD/CAM produced resin crowns. Ten resin blocks were shaped after an upper premolar crown design from the 3Shape Library, and they were divided ino two groups: on Group 1, control, Clarity Advanced braces (3M Unitek, Monrovia, CA, USA) were bonded using XT Adhesive Paste (3M Unitek, Monrovia, CA, USA), while on Groups 2 same aesthetic brackets were applied, using the APC Flash-Free Adhesive Coated Appliance System (3M Unitek, Monrovia, CA, USA). Bracket positioning time was recorded for each sample. Zwick Zoel Z005 testing machine was used to measure the shear bond strength (SBS) at which debonding takes place. Adhesive remnant index (ARI) was registered, as well as presence or absence of adhesive flash and accuracy of flash cleaning before curing. Group 1 showed a mean bonding time of 46.4 s, while Group 2 needed about 20.6 s for each bracket bonding. Mean SBS values for both groups are considered clinically acceptable (6.27 MPa for Group 1 and 7.77 MPa for Group 2). ARI scores were zero for all samples and after debonding, on group 1 can be observed the adhesive flash. In conclusion, APC Flash-Free Coated Appliance System showed reduced time for bracket positioning compared to the conventional technique. APC Flash-Free System showed acceptable SBS values, higher than the uncoated brackets. No composite was left on the resin crown after debonding, the adhesive flash resulted in the conventional technique remaining on the edges of the debonded brackets.
Chemical Additives from the Composition of Plastic Products and Other Materials in Establishing Diagnosis for Alergy Disease
Authors: Raftu Gheorghe , Mitrea Geta , Macovei Luana Andreea , Nechita Aurel
Published: January 2020

Many of the chemical additives in the plastic products, besides the possible safety problems that may arise during the production process, have negative effecty, too, on the environment and human health. Plastic is a synthetic polymer. The polymers include starch, latex and cellulose, combined with different substances and chemicals, used in various formulas, the polymer is included in the naylon. At high temperatures such as microwave oven temperature, polymers can migrate from the packaging plastic in food. In most cases, establishing the diagnosis of allergic disease is a complex and difficult operation. This difficulty is primarily related to the polymorphism of the clinical manifestations accompanying allergic reactions, the existence during the evolution of these conditions, of long clinical asymptomatic latencies, as well as due to numerous subjective and objective symptoms that overlap with those caused by the allergen, complicating and altering the clinical picture. Allergies are an abnormal reaction of the body to allergens and develop in two stages. After the first contact with the allergen, the IgE antibodies are produced, and the second contact produces the allergic reaction. The produced antibodies will release the chemical mediators (histamine, prostaglandine, etc.) which cause an inflammatory response, vascular changes and irritation of the tissues, with the appearance of symptoms specific to allergy: redness, rash, itching, edema, etc.The so complex symptom of allergic diseases comprises several systems and organs at the same time, and the existence of over-additive phenomena makes it impossible to have characteristic clinical symptoms of allergic diseases that allow their identification only by clinical examination. However, this does not mean that the clinical exam and the analysis of the various objective and subjective symptoms presented by the patient is of no importance in establishing the diagnosis and recognizing the allergic character of the disease.The study includes a number of patients studied at the Galati Allergy Clinic. Specific immunotherapy known as desensitization or anti-allergic vaccination, is designed to fight the causes of allergies that occur when the immune system misinterprets harmless substances. Clinical examination results are complemented by allergen and specific antibody research; skin tests are the most common method for allergen detection.
In vitro Study of the Structure and Adhesive Interface in Direct Restorations with Experimental Nanocomposite Materials and Adhesive Systems
Authors: Porumb Anca , Almasi Adrian , Todor Liana , Ratiu Cristian Adrian , Ciavoi Gabriela , Todor Paula Cristina , Todor Sergiu Andrei , Matei Madalina Nicoleta , Romanec Cristian , Matei Ruxandra Ilinca
Published: January 2020

Using nanotechnology to produce composite materials it has been possible to obtain materials with similar or better mechanical properties than previous generation of microhybrids, and with exceptional aesthetics and chandelier due to the particularities of nanomaterials. At the same time, the improvement of adhesive techniques to enamel and dentin allowed the expansion of the area of direct composite restorations with a better prognostic over time.Eight carie-free molars were used and each of them was prepared with two class II cavities, which were filled using the C13 and C20 nanocomposites and the A1 and A2 experimental adhesive systems prepared at the Raluca Ripan Chemistry Research Institute. The teeth were divided into four groups of two teeth each, depending on the adhesive system and the composite material used. Scanning electron microscopy images (SEM) have described the adhesive interface and structure characteristics for the two nanocomposite materials and for the two studied adhesive systems.The studied nanocomposites have a variable number of porosities and air bubbles, with a clinical importance which is yet hard to establish.The experimental adhesives used produce a good interface and infiltration of the smear-layer but have not been visualized inside the dentinal canals.In vitro studies are necessary to evaluate the durability of adhesion in the case of self-etch adhesives in one or two steps.
Packaging Evaluation and Safety Assessment of a Cosmetic Product
Authors: Juncan Anca Maria
Published: January 2020

The aim of this study was the development and formulating of a cosmetic product for bodycare and the assessment of compatibility tests performed on the product, transfered into a poliethylene (PE) cosmetic bottle. Sample of cosmetic cream were stored using 200 ml PE plastic bottles with PP (Polypropylene) 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.
In vivo Evaluation of a Collagen Scaffold Preconditioned with Adipose-derived Mesenchymal Stem Cells Used for Bone Regeneration A histological study
Authors: Pop Tudor Sorin , Pop Anca Maria , Miron Alina Dia Trambitas , Brinzaniuc Klara , Gurzu Simona , Trambitas Cristian
Published: January 2020

The use of collagen scaffolds and stem cells for obtaining a tissue-engineering complex has been an important concept in promoting repair and regeneration of the bone tissue. Such units represent important steps in the development of an ideal scaffold-cell complex that would sustain new bone apposition. The aim of our study was to perform a histologic evaluation of the healing of critical-sized bone defects, using a biologic collagen scaffold with adipose-derived mesenchymal stem cells, in comparison to negative controls created in the adjacent bone. We used 16 Wistar rats and according to the study design 2 calvarial bone defects were created in each animal, one was filled with collagen seeded with adipose-derived stem cells and the other one was considered negative control. During the following month, at weekly intervals, the animals were euthanized and the specimens from bone defects were histologically evaluated. The results showed that these scaffolds were highly biocompatible as only moderate inflammation no rejection reactions were observed. Furthermore, the first signs of osseous healing appeared after two weeks accompanied by angiogenesis. Collagen scaffolds seeded with adipose-derived mesenchymal stem cells can be considered a promising treatment option in bone regeneration of large defects.
Curcumin- Extraction, Physical and Chemical Analysis, Formulas and Control. Basic Methods for Further Research
Authors: Niculet Elena , Neculia Gina Vica , Tatu Alin Laurentiu , Buzia Olimpia Dumitriu
Published: January 2020

Turmeric, with its active component curcumin has been regarded lately as an important potential therapeutic agent due to its properties and many uses. Further research needs to be done both on animals and humans in order for it to be used at a large scale. As curcumin gets absorbed better through topical and not oral administration, curcumin-based pharmaceuticals with skin passage must be devised. In order for this to be done, the need for a standardized, verified and simple extraction method and one for ointment preparation with stability in time rises. We propose in this study a method for curcumin extraction, one that ensures an adequate stability in time and a method for pharmaceutical control.
Execution of Non-Metallic or Metallic Duplicates, Cast with 3D Scanners and 3D Printers
Authors: Motomancea Adrian , Bucuresteanu Anca , Prodan Dan
Published: January 2020

In this paper, the authors show a part of research works performed on the use of 3D scanners and 3D printers to execute the molds required for the cast of parts with complex surfaces. 3D scanning allows copying of certain surfaces in our environment, based on existing models. The finished parts may also be executed from metals that are relatively easy to cast (bronze, aluminum etc.). In order to execute the molds destined for the casting, various pieces may be scanned, with a volume size in the range of [150x150x200 mm3 ÷ 500x500x2000 mm3]. Plastic model printing is performed depending on the capacity of the 3D printer used. This paper shows the results achieved with general-purpose scanner and printer, valued at affordable prices.
A Meso Level FE Model for the Impact Bullet - Yarn
Authors: Pirvu Catalin , Musteata Andrea Elena , Ojoc George Ghiocel , Sandu Simona , Deleanu Lorena
Published: January 2020

This paper presents a study based on simulating the impact between a yarn (or a single fiber with greater dimensions) and a bullet, the impact velocity being 400 m/s. The characteristics of the involved materials are taken from literature. The yarn is considered isotrope, but the values of the characteristics are close to those of aramid fibers and cooper and lead alloys used for manufacturing the bullets. Analysing the yarn failure caused by a bullet, this FE model allows for identfying the stages in the failure process. First, the yarn is pushed by the bullet and the local elongation of the yarn is tacking place. The yarn rupture occurs in the �strangled� zones, caused by the stretch of the yarn directly supporting the impact. The breaking of the yarn in the thinned zone (more pronounced asymmetric breaking) and it is visible that the yarn elastic recoil starts next the bullet. The friction between the yarn and the bullet is only on the conical surface of the bullet in the tapered zone of the bullet. The yarn is detaching from the bullet (the contact zones between the bullet and the yarn in polymeric matrix become smaller, justifying a neglectable influence of the thermal effect). The yarn has no more contact with the bullet. This step is in the favor of the assumption that, in the actual multi-yarn impact, the other layers of yarns maintain the bullet and the first yarns in contact and this is why bunch of fibers (fragments of the failed yarns) are pressed against the bullet and remain on it. The simulation results were qualitatively validated by SEM investigations of fiber failure under the same conditions as the model.
Iono-molecular Separation with Composite Membranes. VIII. Recuperative aluminium ions separation on capilary Polypropylene S-EPDM composite membranes
Authors: Nafliu Ion Marius , Al-Ani Hussam Nadum Abdalraheem , Grosu (Miron) Alexandra Raluca , Albu Paul Constantin , Nechifor Gheorghe
Published: January 2020

Environmental problems occurring in isolated or hardly accessible inhabited areas can be adequately addressed using membranes and membrane processes.In the present paper, the recuperative separation of aluminum ion from the aluminum sulfate-treated water through permeation using capillary composite membranes, from polypropylene with ethylene propylene diene terpolymer sulfonic acid (PP / S-EPDM) inclusions is followed by the reaction of complexation with 8-hydroxy quinoline. The installation used for studying the permeation process provides a usable surface area of 1 m2, the source phase solution volume is 3 L, and the receiving phase is 300 mL. The two phases are recirculated through the outside of the membranes (SP) and respectively through membranes (RP), by means of individual peristaltic pump that can provide flow variations between 2 and 200 mL / min by varying the intensity of the power supply. The optimal operating parameters were determined: operating time, pH and receiving phase flow, thus achieving an ionic flux (IR) above 10-11 mol / cm 2. s and a recovery factor (RF) over 90%.
Aspects of Heart Failure in Patients with Ischemic Heart Disease after Percutaneous Coronary Revascularization with Polymer-coated Drug-Eluting Stents versus Bare-Metal Stents
Authors: Tudoran Mariana , Tudoran Cristina , Ciocarlie Tudor , Pop Gheorghe Nicusor , Berceanu-Vaduva marcel Mihai , Velimirovici Dana Emilia , Ahmed Abu Awwad , Berceanu-Vaduva Delia Mira
Published: January 2020

Percutaneous coronary revascularization (PCR) with polymer-coated drug-eluting stents (DES) or bare-metal stents (BMS) is considered the standard therapy in advanced ischemic heart disease (IHD). Despite revascularisation, many of these patients subsequently develop heart failure with reduced ejection fraction (HFrEF). We analysed 51 patients with IHD, treated by PCR and insertion of DES and/or BMS who later developed HFrEF. Patients with DES where more likely women, of younger age and a higher incidence of diabetes mellitus compared to patients with BMS who were generally men, of older age and had more frequently acute ST-elevation myocardial infarction (STEMI) as indication for PCR. Although patients with DES had more severe IHD, their EF was higher, possibly due to the benefits offered by the DES.
Assessment of Paint Layers Quality by FTIR and DSC Techniques
Authors: Lungulescu Eduard-Marius , Lingvay Iosif , Bors Adriana-Mariana , Fortuna Laszlo , Nicula (Butoi) Nicoleta-Oana
Published: January 2020

In order to identify the causes that led to microbiological degradation by biofouling increases a top coat painting layer applied to a railway bridge was analyzed by both FTIR and the DSC methods; the analysed painting material was that used to paint the bridge in 2013.The determinations were performed comparatively on samples of a similar painting material after 10 days of curing in a natural atmosphere at 25 � 5 �C, after 60 days of storage under laboratory conditions (22 � 5 �C, RH 60 � 10 %, natural lighting), and on samples from the painting material of a certain railway bridge after approx. 4.5 years (exposed natural weathering of temperate climate with Mediterranean influences). From FTIR determinations, the amount of oxygen containing groups (C = O, C-O, C-O-C, -HO) resulted from ageing under various conditions of the painting material.From DSC determinations, the resistance of the paint to the oxidative degradation decreases with the ageing time as resulted from oxidation onset temperatures and oxidation activation energies values - which decreases with 4 kJ / mole (about 2.2 %) in only 60 days of storage in the laboratory and with 7 kJ/mole (about 3.9 %) following exposure to 100 w/m2 for only 15 h and 29 kJ / mole (over 16 %) after exposure to 4.5 years of natural weathering.
Resin Based Materials used to Observing the Variations of the Origin of the Superior Thyroid Artery with Importance in Cervical and Cranial Pathology
Authors: Bordei Petru , Iliescu Dan Marcel , Rusali Lavinia Maria , Hainarosie Razvan , Jecan Radu Cristian , Popa Cristian Constantin , Ardeleanu Valeriu
Published: January 2020

The superior thyroid artery shows a great variability in what concerns its origin. Most often, it appears as an independent branch of the external carotid artery, as its first collateral branch, or directly from the common carotid or at its terminal level. The superior thyroid artery origin was evaluated on 144 cases, using as study methods the dissection (39 cases), the plastic injection (22 cases) and the CT angiography evaluation (83 cases). It was studied, by percentage, the originating artery of the superior thyroid artery, the relation to the bifurcation of the common carotid artery, the neighboring arterial branches and the surface of the external carotid on which originated, the caliber of the external carotid artery before and after the origin of the superior thyroid artery. Most commonly, in 89 cases (61.80%), we describe the origin of the superior thyroid artery from the external carotid artery; from the common carotid artery originated 31 superior thyroid arteries (21.53%); at the level of the bifurcation of the common carotid artery, the superior thyroid artery had its origin in 21 cases (14.58%); in 2 cases (1.39%) we encountered the superior thyroid artery originating from a thyro-lingual trunk and in one case (0.69%), we met a thyro-linguo-facial trunk. The superior thyroid arteries may originate as an independent artery or as arterial trunks in varying proportions. When the origin of the superior thyroid artery is from the terminal common carotid, we propose to use the expression of terminal branching or the common carotid artery trifurcation. The results of our study are similar to those found in international literature, with statistical differences that may be attributed primarily to the total number of cases on which we worked and also working methods or may be attributed to other causes, such as the geographic area where the study was conducted and the amount of time the results were obtained.