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In this study, mechanical responses of a friction welded AA6013/AA7075 aluminum alloy beam are investigated. For this purpose, the experimental study is conducted with two different friction welding parameters (i.e., rotational speed and welding pressure) and two constant friction welding parameters (i.e., friction pressure and contact time). Microstructural and mechanical performance analyses (i.e., macrohardness and tensile measurements) are considered to determine the weld quality. Effects of speed and welding pressure on the vibration characteristics/structural performances are also examined experimentally. Advantages of using vibration analysis are discussed to understand the effects of different weld parameters. Results are given in tabular and graphical forms.

Bioceramics are a fast-growing materials group, which are widely used in orthopedics, maxillofacial, dental, and reconstructive surgeries. They are produced using raw materials either from synthetic or natural sources. As naturally originated resources, the bones of sheep and cows are used after converting to calcium phosphates. Human-originated sources in the past were obtained from human cadaver bones, however now-a-days this has been discontinued. On the other hand, the “golden standard” in the reconstruction surgery has been using patients own bones, -i.e., autogenous bones, which heal better than other alternatives. Besides natural products, synthetic materials are produced from a range of inorganic raw and natural materials based on marine sources, such as corals, and other marine-derived materials (i.e., seashells, nacre). These are used to produce bioceramics and hence implants, devices, and bone grafts. Although during the last four decades a number of excellent books and book chapters have been published, no comprehensive review has been yet reported to cover the available marine materials and to indicate the related work and corresponding references to allow for both medical and ceramic scientists to access directly and open new avenues for further research on marine structures and their applications in orthopedic, maxillofacial, and reconstructive surgery areas. Hence, this review covers the general marine structures, their locations and availability in different countries and, current research on production methods of these unique structures that are difficult to fabricate synthetically. The authors are confident that this comprehensive review will be an excellent source not only for the ceramists, but also for the medical scientists.

Bracket failure is one of the most important problems encountered during fixed orthodontic treatment. For this reason, different types of adhesive agents have been developed over the years. Consequently, the aim of this study was to evaluate the shear bond strength of brackets bonded to teeth etched with a conventional acid etching method in a laboratory environment by using different types of adhesive agents and comparing the number of shear strokes. Sixty human maxillary premolars were divided into three groups and Gemini stainless steel metal brackets (3M Unitek, Monrovia, CA, USA) were bonded to all teeth. In Group 1, Transbond™ XT Primer (3M Unitek, Monrovia, CA, USA) and Transbond™ XT Light Cure Adhesive Paste composite (3M Unitek, Monrovia, CA, USA) were used. In Group 2, BracePaste® MTP Primer (American Orthodontics, Sheboygan, CA, USA) and BracePaste® Adhesive composite (American Orthodontics, Sheboygan, WI, USA) were used. In Group 3, Ortho Solo™ Primer (Ormco, Orange, CA, USA) and Grengloo™ Adhesive composite (Ormco, Brea, CA, USA) were used. The samples were subjected to a shear test with a closed-loop controlled, low-cycle fatigue machine with a capacity of 10 N and a crosshead speed of 300 mm/min. The number of shear strokes of the brackets was recorded. According to the Kruskal–Wallis and Mann–Whitney U tests performed on the data obtained, statistically significant differences were found between the groups in terms of the numbers of shear strokes (p < 0.05). Significantly higher numbers of shear strokes and higher shear bond strengths were observed in Group 3 compared with Group 1 and Group 2 (p < 0.05). There was no statistically significant difference between the numbers of shear strokes for Group 1 and Group 2 samples (p > 0.05). To conclude the study, it was observed that the type of adhesive used had an effect on the bond strength of the bracket and that the Grengloo™ adhesive agent showed higher shear bond strength. It was observed that BracePaste® Adhesive and Transbond™ XT Light Cure Adhesive Paste adhesive agents had similar shear bond strengths.

The aim of this study is to obtain pure natural hydroxyapatite (HAp) and tricalcium phosphate (TCP) from a Goniopora spp. and from hump coral (Porites cylindrica), both sourced from Australia. Due to the nature of the conversion process, commercial coralline HAp has retained coral or CaCO3, and the structure possesses both nano- and mesopores within the interpore trabeculae resulting in high dissolution rates. To overcome these limitations, a newly patented coral double-conversion technique has been developed. The current technique involves a two-stage application route where in the first-stage complete conversion of coral to pure HAp is achieved. In the second stage, a sol-gel-derived HAp nanocoating is directly applied to cover the meso- and nanopores within the intrapore material, while maintaining the large pores. Here, we specifically investigated the morphological changes and characterized these corals prior to and after conversion. For this purpose, four groups designated as C0, C1, C2, and C3 were used. C0 is Porites, Goniopora, and cylindrica; the original coral is calcium carbonate with aragonite structure that contains proteins and polysaccharides. C1 is coral cleaned under ultrasound in bleach diluted with water. C2 is coral converted to hydroxyapatite (HAp) by hydrothermal treatment method at 200 °C under pressure in the presence of ammonium biphosphate. C3 is obtained by coating C2 with sol-gel alkoxide-derived nanohydroxyapatite to obtain a more bioactive osteoconductive material and improve mechanical properties. All groups were characterized by XRD, EDAX, DTA/TGA, and SEM. The results showed that the biaxial strengths of the C2 and C3 were significantly higher than the original coral. The work also showed the advantages of the hydrothermal conversion method and the effect of the nanocoating which is expected to improve the final bioactivity through microstructural changes of the surfaces. © 2019, Australian Ceramic Society.

In this study, numerical dynamic analysis of E-glass fiber plain weave composite beams with crack under compression is considered. Before understanding the compression effect on the beam, the dynamic characteristics of the models are compared with the experimental evaluations. Results are given in tabular and graphical form.

In this study, sintering effects on microstructural behavior of bovine derived hydroxyapatite doped with powder mullite are considered in the temperature range between 1000 °C and 1300 °C. Results show that maximum values of both compressive strength and microhardness are achieved in the samples sintered at 1200 °C for all mullite additions of 5, 7.5, 10 and 12.5 wt%. Moreover, above 1000 °C, decomposition of HA and new phase formations such as whitlockite and gehlenite play a major role in both compressive strength and microhardness properties which increase up to 10 wt% mullite reinforcement. © 2017 Elsevier B.V.

Objective Development of immunologically smart implants, integrated to biological systems, is a key aim to minimize the inflammatory response of the host to biomaterial implants. Methods The aim of this study is to investigate the influence of titanium alloy and stainless steel implants on immunological responses in rats by comparative analysis of nuclear factor kappa B (NF-κB) profiles in the activation of inflammatory signaling pathways and the role of CD4+CD25+Foxp3+. Results Both Ti alloy and stainless steel alloy group implantation affect Toll-like receptors-4 pathways and CD4+CD25+ regulatory T cells in different ways. Conclusions Results show that NF-κB/p65 and NF-κB1/p50 possess potential as a therapeutic target in the prevention of adverse reactions to metal, especially for controlling inflammation after the implantation.

Based on the development of many adhesive systems and bonding techniques, bonding strength of orthodontic brackets has become even more important in modern clinical orthodontics. The aim of this study was to determine mean shearing stroke frequency of different orthodontic bracket types and bonding agents under cycling loading. Therefore, 10 different types of orthodontic bracket from 4 different brands were divided into 2 groups. Two different adhesives, namely Transbond&trade, XT etch-and-rinse for Group 1 and Transbond&trade, Plus self-etching-primer adhesive for Group 2 were considered. The brackets were tested under cycling loading force of 10-N and a crosshead speed of 300 mm/min and 40 cycle/min. The frequency of strokes that the brackets failed were determined and these data were analyzed by statistical analysis using an independent sample t-test and one-way analysis of variance (ANOVA). The level of significance was set at p &lt, 0.05. Generally, differences between the frequency of shearing strokes of the bracket failures were found to be statistically significant depending on the type of adhesives and brackets (p &lt, 0.05). The bonding technique for Group 1 was found to have a significantly higher shear bonding strength than Group 2. It is also seen that different types of bracket belonging to the same or different brands had different shear bonding strength. It may be concluded that: (i) all bracket types used in this study can be applied with both bonding techniques, (ii) in order to minimize the risk of hard tissue damage, ceramic brackets should be carefully bonded using the self-etching primary adhesive technique.

In this study, mechanical properties and microstructural analysis of goat-derived hydroxyapatite/commercial inert glass biocomposites are considered in the temperature range between 1000 and 1300 °C. The results indicate that the best values of maximum compressive strength and microhardness are achieved in the samples sintered at 1200 °C for the glass in the weight of 5 and 10%. Moreover, above 1000 °C, decomposition of hydroxyapatite and new phase formations such as whitlockite and silicocarnotite play also a major role in the hardness and strength for goat hydroxyapatite/commercial inert glass biocomposites. © 2018, Australian Ceramic Society.

Mesoporous materials synthesized in the presence of templates, are commonly used for environment and medical applications. Due to the properties it holds, mesoporous silica nanoparticles is an excellent material for use in medical field, biomaterials, active principles delivery systems, enzyme immobilization and imaging. Their structure allows embedding large and small molecules, DNA adsorption and genetic transfer. Using mesoporous silica nanoparticles for delivery of bioactive molecules can protect them against degradation under physiological conditions, allow controlled drugs release and minimize side effects on healthy tissues. Cellular tests performed on mesoporous silica nanoparticles demonstrate that MSN's cytotoxicity is dependent on the size and concentration and suggests the use of larger size nanoparticles is optimal for medical applications. Mesoporous materials possess high biological compatibility, are non-toxic and can be easily modified by functionalizing the surface or inside the pores by grafting or co-condensation method. The structure, composition and pores size of this material can be optimized during synthesis by varying the stoichiometric reactants, reaction conditions, nature of the template’s molecules or by functionalization method. © 2015 Bentham Science Publishers.

In this study, the vibro-acoustic behaviour of centrally damaged honeycomb cored sandwich panels is investigated experimentally. For this purpose, experimental evaluations are completed by the followings: (I) honeycomb sandwich panels with two different core materials and the same skin materials are considered, (II) low-velocity impact measurements with three different projectiles are obtained, (III) vibration and vibro-acoustic tests are performed to present the vibration characteristics of the post-impacted sandwich panels with two different boundary conditions. Effect of core material and projectile geometry on modal and sound characteristics is examined. The results are given in tabular and graphical forms. In dieser Studie wird das vibro-akustische Verhalten von zentral geschadigten Wabenkern-Sandwichplatten experimentell untersucht. Zu diesem Zweck werden folgende Untersuchungen durchgefuhrt: (I) Berucksichtigung von Wabenplatten mit zwei verschiedenen Kernmaterialien und gleichen Deckschichtmaterialien, (II) Messungen bei geringen Stosgeschwindigkeiten mit drei verschiedenen Stoskorpermodellen, (III) Durchfuhrung von Vibrations- und vibro-akustischen Tests, um das Schwingungsverhalten von Sandwichplatten nach Stosbelastung bei zwei unterschiedlichen Randbedingungen zu bestimmen. Die Ergebnisse werden in tabellarischer und grafischer Form angegeben.

2nd International Conference on Frontiers of Composite Materials, ICFCM 2017 -- 15 November 2017 through 17 November 2017 -- -- 213839, Nowadays hydroxyapatite (HA) bioceramics are very important because increasing traffic accidents and ageing of the population. They can be produced from synthetic or natural sources with different production methods. The biggest negative issue of HA is being very brittle and unstable under pressure. Various materials are added for restoring these weaknesses, but there is not so much studies adding nano-ingredients for restoring the mechanical properties of HA. In this study, 5-10% nano-yittria-oxide is added to bovine derived HA (BHA) and to commercial synthetic (CSHA) as a control group. Physical and mechanical properties are examined. Results show that adding of nano-ingredients are really helping to mechanical properties of HA. © 2018 Trans Tech Publications, Switzerland., FEN-C-YLP-120417-0177 2016K121280, This study is granted by Marmara University, BAPKO foundation (Project No: FEN-C-YLP-120417-0177) and Republic of Turkey Ministry of Development (Project No: 2016K121280).

6th International Conference on Material Science and Engineering Technology, ICMSET 2017 -- 20 October 2017 through 22 October 2017 -- -- 212519, In this study, modal stress analysis of carbon fiber plain weave cracked composite beams under compression is considered. General-purpose finite element code MSC. Marc is used for the finite element beam models. Before understanding the compression effect on the beam, dynamic characteristics of the models are compared with the experimental evaluations. Investigation of quasi-static and dynamic (equivalent von Mises stress and elastic strain energy density) behavior of the plain weave cracked beams with two different thicknesses under compression is examined numerically. Results are given in tabular and graphical form. © 2018 Trans Tech Publications, Switzerland., Firat University Scientific Research Projects Management Unit 2014-77654622-01 British Association for Psychopharmacology, This work was supported by the Scientific Research Projects Unit (BAP) of Bulent Ecevit University (project code no: 2014-77654622-01).

Tendo kopukları çoğunlukla ekstremitelerin distal kısımlarında meydana gelmekte ve uzun süreli bir iyileşme periyodu gerektirmektedir. Travmatik aşil tendo kopuklarında operasyon öncesi ve sonrasını da kapsayan 6 -8 haftalık bir bandaj uygulaması ile hareketsizlik sağlanmaktadır. Bu uygulamanın neden olacağı diğer ortopedik problemleri önlemek ve iyileşme periyodunu hızlandırabilmek amacıyla, operasyon sonrası lokal uygulamalar yapılmaktadır. Ultrason terapi (TUS) bunlardan biridir. Fonofo rezis ise emilim ö zelliği olan ilaçların TUS eşliğinde lokal olarak bölgeye emdirilmesidir. Deneysel çalışmamızda 40 adet erkek, 1 yaşında, ortalama 3 kg ağırlığında, Yeni Zelanda tavşanı kullanıldı. Tavşanlar 4 gruba ayrıldı ve tüm tavşanların her iki arka bacağında deneysel Aşil tendo rupturu oluşturuldu ve hemen akabinde tenorafi ile onarıldı. Birinci ve üçüncü gruptaki tavşanların sağ bacaklarına operasyondan sonraki 10 gün boyunca ultrason terapi uygulandı. İkinci ve dördüncü gruptaki tavşanların sağ bacaklarına ise ope rasyondan sonraki 10 gün boyunca fonoforez uygulandı. Tüm çalışma gruplarında, sol bacaklar kontrol grubunu oluşturdu. Tavşanlar 30. gün sonunda ötenazi edilerek grup 1 ve 2’deki örnekler histopatolojik olarak, grup 3 ve 4’teki örnekler ise biyomekanik olarak incelendi. Biyomekanik inceleme için tendoların kopma noktaları N (Newton) cinsinden karşılaştırıldı. Çalışmanın sonucunda; ultrason terapinin fonoforezle karşılaştırıldığında tendo iyileşmesi için daha üstün bir metod olduğu kanısına varıldı., Tendon ruptures occur generally at distal portions of extremities and require relatively long recovery period. Traumatic ruptures of Achilles tendon need 6 -8 weeks of immobility period including pre and postoperative days. In order to avoid other orthopedical problems by this application and to speed up the reco very period, postoperative local administrations are done. Therapeutic Ultrasound (TUS) is one of these applications. Phonophoresis is the local absorbing procedure of some drugs by me ans of TUS which is applied to the affected area. Forty male New Zealand rabbits were used in the study which were one year old and mean 3 kg body -weight. The rabbits were divided into 4 groups and experimental Achilles tendon rupture was created in both legs of all rabbits and repaired immediately by tenorrhaphy. The right le gs of rabbits of groups 1 and 3 were treated postoperatively with TUS for 10 days. The right legs of rabbits in groups 2 and 4 were treated postoperatively with phonophoresis for 10 days. Left legs of all rabbits served as the control group. All rabbits we re euthanized at the end of the 30th day. Samples which were taken from groups 1 and 2 were examined histopathologically and those in groups 3 and 4 were examined biomechanically. In biomechanical investigations, the rupture points of the tendons in N (Newton) were compared. At the end of the study, it was concluded that TUS is a superior for tendon healing when compared to phonophoresis.

Laminated curved glasses as widely used elements in buildings urge to develop a mathematical model for their analysis and safer design. Large deflection theory is necessary in order to predict the true behavior of a laminated curved glass beam consisting of several glass layers bonded by soft interlayer PVB (PolyVinyl Butyral). In the present study, a mathematical model is developed for the analysis of a laminated circular arch or a laminated uniformly curved glass beam which is the special case of the laminated curved glass beams. Thus, three nonlinear, coupled partial differential equations governing the true behavior are derived in polar coordinates by applying variational and energy principles. Results of this model are compared with the results from the experiments and finite element model, and all of them are presented in figures to explain the true behavior. © 2013 Elsevier Ltd.

Amaç: Çalışmanın amacı ortodontik yüz maskesi kullanım süresi ve düzenini takip etmek amacıyla yüz maskesinin alın kısmına takılan yeni bir izleme sisteminin sunulması ve değerlendirilmesidir.Gereç ve Yöntem: Yeni izleme sistemi ana gövde, yuva kapağı ve sensör olmak üzere 3 ana parçadan oluşmaktadır. Ana gövde iki adet yan sabitleyici, bir adet orta sabitleyici, sensör takma yuvası ve sekiz vida deliğinden oluşmaktadır. Ana gövdedeki tüm parçaların yerleştirilmesini takiben sensör programlanmış ve yuvaya yerleştirilmiştir daha sonra kapak sabitlenmiştir. Sistem laboratuvar koşullarında test edilmiştir.Bulgular: Çalışma sonunda elde edilen verinin detaylı analizi göstermiştir ki izleme sistemi takma ve sökme süreçlerini doğru bir şekilde takip etmektedir. Yeni tipteki ortodontik yüz maskesi takma sürelerini ve düzenini izleyebilmektedir. Sonuç: Yüz maskesi tedavisi sagital yöndeki üst çene yetersizliğinin düzeltilmesinde elzemdir. Toplam kullanım süresi ve düzenli kullanım ortodontik ve ortopedik tedavinin başarısını etkileyen temel faktörlerdir. Objektif ve bilimsel olarak bu sürecin izlenmesi bu meşakkatli, uzun ve pahalı tedavide klinisyenlere büyük katkı sağlayacaktır. Bu çalışmanın sonucu göstermiştir ki yeni izleme sistemi yüz maskesi kullanımı için uygundur., Introduction: The aim of this study is to present and evaluate a new monitoring system attached to forehead part of face mask for tracking orthodontic face mask usage time and regularity. Methods: The new monitoring system consists of three main parts as main body, slot cover and sensor. The main body includes two lateral fixer, a median fixer, sensor insertion slot and eight screw holes. After completing the assembly procedure for the main part, the sensor is programmed and inserted to its slot and then the cover is screwed. The system was tested under laboratory condition.Results: Detailed analysis of the post study data showed that the system measured the attachment and detachment period correctly. The new type orthodontic face mask can monitor the wearing time and regularity.Conclusion: Face mask therapy is a crucial for correction of sagittal maxillary deficiency. Total wearing time and regularity is main factors to reach to a success level of this orthodontic and orthopedic treatment. Objective and scientific monitoring system proposed here may help the clinicians for difficult, long and expensive treatment. Conclusion of present study show that the system proposed is suitable for the further face mask usage.

As there is a gap in literature about out-of-plane vibrations of curved and variable cross-sectioned beams, the aim of this study is to analyze the free out-of-plane vibrations of curved beams which are symmetrically and nonsymmetrically tapered. Out-of-plane free vibration of curved uniform and tapered beams with additional mass is also investigated. Finite element method is used for all analyses. Curvature type is assumed to be circular. For the different boundary conditions, natural frequencies of both symmetrical and unsymmetrical tapered beams are given together with that of uniform tapered beam. Bending, torsional, and rotary inertia effects are considered with respect to no-shear effect. Variations of natural frequencies with additional mass and the mass location are examined. Results are given in tabular form. It is concluded that (i) for the uniform tapered beam there is a good agreement between the results of this study and that of literature and (ii) for the symmetrical curved tapered beam there is also a good agreement between the results of this study and that of a finite element model by using MSC.Marc. Results of out-of-plane free vibration of symmetrically tapered beams for specified boundary conditions are addressed. © 2017 Hamdi Alper Özyigit et al.

Nanotechnology has tremendous potential to revolutionize dentistry as a whole and can also introduce significant benefits to human society by improving health and presenting better use of natural resources. Nanomaterials and nanoparticles are likely to be cornerstones of innovative nanodental applications. It is believed that nanodentistry will improve the human quality of life for the twenty-first century. © 2016 Elsevier Inc. All rights reserved., Unitatea Executiva pentru Finantarea Invatamantului Superior, a Cercetarii, Dezvoltarii si Inovarii, The work has been funded by PN-II-PT-PCCA-2013-4-0891 project “Innovative dental products with multiple applications–LavEndo” funded by UEFISCDI.

In this chapter, essentials of finite element analysis on musculoskeletal biomechanics are studied. For this reason, some fundamental types of finite elements, methodology, and difficulties of finite element analysis are considered. Also, some information on well-known general purpose finite element codes preferred in biomechanics and biomaterials world is given. Before discussing orthopedic researches for clinical relevance, an example of two-dimensional finite element analysis is examined. © Springer International Publishing Switzerland 2016.

In this study, a symmetrical finite strip with a length of 2 L and a width of 2 h , containing a transverse symmetrical crack of width 2 a at the midplane is considered. Two rigid plates are bonded to the ends of the strip through which uniformly distributed axial tensile load of magnitude 2 hp 0 is applied. The material of the strip is assumed to be linearly elastic and isotropic. Both edges of the strip are free of stresses. Solution for this finite strip problem is obtained by means of an infinite strip of width 2 h which contains a crack of width 2 a at y = 0 and two rigid inclusions of width 2 c at y = ± L and which is subjected to uniformly distributed axial tensile load of magnitude 2 hp 0 at y = ±∞. When the width of the rigid inclusions approach the width of the strip, i.e., when c → h , the portion of the infinite strip between the inclusions becomes identical with the finite strip problem. Fourier transform technique is used to solve the governing equations which are reduced to a system of three singular integral equations. By using the Gauss–Jacobi and the Gauss–Lobatto integration formulas, these integral equations are converted to a system of linear algebraic equations which is solved numerically. Normal and shearing stress distributions and the stress intensity factors at the edges of the crack and at the corners of the finite strip are calculated. Results are presented in graphical and tabular forms.

The emergence of multi-resistant bacteria to drugs is recognized as a major cause of the increasing number of deaths in hospitals. Killing these bacteria require multiple expensive drugs that can have side effects. Metal nanoparticles may provide a new strategy to combat them. Due the antimicrobial and antiviral properties, nanoparticles (NPs) have outstanding biological properties that can be handled properly for desired applications. This review presents antibacterial and antiviral activity of metal NPs, including the molecular mechanisms by which NPs annihilate multidrug-resistant bacteria. © 2015 Bentham Science Publishers.

In this study, the mechanical properties of two different permanent soft lining materials and their bonding to poly(methyl methacrylate) (PMMA) were compared. Both of the soft liners were heat-cured commercial materials. The polymerization was carried out by conventional methods suggested by manufacturer, and the curing was done at the temperature of boiling water for 5, 15, 25, and 35 min. The sample groups were tested in the computer-aided tensile-testing machine at a rate of 2 mm/min. The slow rate helps the collection of more and more reliable data. At this time, the stress–strain curves were used to calculate ultimate tensile strength, elastic modulus, resilience, and toughness. The measurements were carried for PMMA, Molloplast B, Flexor, and a combination of PMMA/soft liner. After introducing the soft lining material on PMMA of the same thickness, the new material structure was more elastic than the original PMMA. Flexor showed adhesive failure at studied curing periods, but Molloplast B gave larger tear strength values and cohesive rather than adhesive failure at the 25-min and 35-min curing times. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 467–474, 2002

In this study, in order to determine the very early load transfer behavior in the bolted joint connection, experimental dynamic analysis of different laminated glass beams including two surface cracks is considered. For this purpose, both three different plastic interlayers (i.e., three types of polyvinyl butyral—PVB) and three different glass-lamina thicknesses are taken into account. Effects of the plastic interlayer, thickness of the glass-lamina, number of surface cracks and their locations on the vibration characteristics/structural performances are examined experimentally. Vibration tests are performed to present free vibration characteristics of the laminated glass beams under clamped-free boundary conditions. Experimental dynamic analysis consists of six parts: (I) vibration analysis with no-crack and no-hole with a bolted joint; (II) vibration analysis with a surface crack and no-hole with a bolted joint; (III) vibration analysis with two surface cracks and no-hole with a bolted joint; (IV) vibration analysis with no-crack and a hole with a bolted joint; (V) vibration analysis with a surface crack and a hole with a bolted joint; (VI) vibration analysis with two surface cracks and a hole with a bolted joint. For these experimental steps, an impact hammer with a force transducer is used to excite the uncracked or cracked composite beams through the selected points. After the excitation, the responses are obtained by an accelerometer. The vibration measurements are completed using a microprocessor-based data acquisition system and nCode GlyphWorks software. Results are given in tabular and graphical forms.

This work covers studies on systems with car tire regrind used as the toughening phase in epoxy resins. Different surface modification techniques were used to improve the compatibility at the interface between the rubber particles and the epoxy matrix. Silane coupling agents, plasma surface modification and acrylic acid/benzoylperoxide were used to enhance the surface properties of rubber particles. Rubber parts of ground used car tires, with or without surface treatment, were mixed with epoxy. This mixture was poured into molds to obtain mechanical test specimens according to ASTM standards. After curing, mechanical tests were performed and the fractured surfaces of the specimens were examined under Scanning Electron Microscopy, SEM. Throughout the studies, changes in mechanical properties were followed by an increase in the volume percentage of rubber particles and by the effect of different surface treatment processes applied on rubber. A decrease in tensile properties and impact resistance was observed in general as compared to unmodified epoxy. On the other hand, slight increases in fracture toughness values were observed in all surface treated cases.

nofulltext# --- Şahin, Yeşim Müge (Arel Author), The present review is intended to bring together the main advances in the field of nanostructured biomaterials with antimicrobial properties. It is generally accepted that the discovery of antibiotics was of great importance but, nowadays new antimicrobial agents are needed and/or their better administration routes. The limitation of the use of antibiotics is essential because of the following reasons: the excessive use of antibiotics leads to the development of antibiotic resistant microorganisms; there are some alternatives for many types of infections, many of these alternatives being less toxic and do not lead to antibiotic similar resistance. In compliance with the above presented, the use of antibiotic is recommended to be eliminated (when alternatives are available) or to be reduced by using combined therapy when possible or to administrate these drugs through targeted or loco-regional drug delivery systems.

Orleans University, France;Samara State Aerospace University, Russia, 5th International Conference on Mechanical and Aerospace Engineering, ICMAE 2014 -- 18 July 2014 through 19 July 2014 -- Madrid -- 107490, In this study, dynamic analysis of carbon plain weave square plates with different damage patterns including pattern of post-low velocity impact and patterns of post-ballistic impact is considered. For this purpose, vibration tests are performed to present the vibration characteristics of the four-edge clamped square plates. Effects of bullet-tip geometry, projectile velocity and impact damage location on the vibration characteristics are examined experimentally. Results are given in graphical form. © (2014) Trans Tech Publications, Switzerland.

The fabrication and characterization of bovine hydroxyapatite (BHA) and cerium oxide (CeO2) composites are presented. CeO2 (at varying concentrations 1, 5 and 10wt%) were added to calcinated BHA powder. The resulting mixtures were shaped into green cylindrical samples by powder pressing (350MPa) followed by sintering in air (1000-1300°C for 4h). Density, Vickers microhardness (HV), compression strength, scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were performed on the products. The sintering behavior, microstructural characteristics and mechanical properties were evaluated. Differences in the sintering temperature (for 1wt% CeO2 composites) between 1200 and 1300°C, show a 3.3% increase in the microhardness (564 and 582.75HV, respectively). Composites prepared at 1300°C demonstrate the greatest compression strength with comparable results for 5 and 10wt% CeO2 content (106 and 107MPa) which are significantly better than those for 1wt% and those that do not include any CeO2 (90 and below 60MPa, respectively). The results obtained suggest optimal parameters to be used in preparation of BHA and CeO2 composites, while also highlighting the potential of such materials in several biomedical engineering applications. © 2014 Elsevier Ltd., 2003K120810, This study was carried out mainly with the equipment furnished (between 2007–2008) to Marmara University with the support of the Turkish Republic Government Planning Organization in the framework of the project 2003K120810 “Manufacturing and Characterization of Electro-Conductive Bioceramics”.

In this chapter, free vibration analysis of a clamped-free E-glass composite elliptical shell with an interior carbon composite plate is studied. At one end of the carbon/epoxy plain weave composite plate, two Al2024-T3 bars are attached. Vibration tests are performed to present the free vibration characteristics of the clamped-free composite structure provided by TAI-Turkish Aerospace Industry Inc. Effects of the structural parts on the vibration characteristics are examined both experimentally and numerically. In order to explore the possibilities for further finite element research on such vibration analysis, the sub-structural effects on the numerical model is considered in a limited manner.

In this study, dynamic analysis of carbon fiber T-plates with different damage patterns including cracks and impact-damaged region is considered. For this purpose, vibration tests are performed to present the free vibration characteristics of clamped-free carbon fiber-plain weave composite T-plates provided by TAI-Turkish Aerospace Industry Inc. A general purpose finite element code (ANSYS) is used to confirm the experimentally measured natural frequencies. Effects of damage type, size and location on the vibration characteristics are examined both experimentally and numerically. The thickness effect is also investigated.

Muscle groups affected on biting force are called temporal muscle as a major and masseter muscle as a minor. According to the human posture stability, forces of these muscles vary with the force directions. In this case, experimental investigation is strictly important such that biting force under different postural and eye- positional situations is changed. In this study, seven-male and seven-female within the age-range of 17-24 are considered corresponding to having with restorated molar tooth and without that type of tooth. With the help of specially designed biting fork, different posture- and eye-positions are investigated for experimental biting force analysis. Changes in eye-positions are not indicated significant difference for all postural positions. On one hand, it is obtained that biting force of no-filling tooth in men becomes maximum if facial muscles give full effort to biting. On the other hand, effect of facial muscles for women is not clearly noticed depending on the postural differences.

23rd Symposium and Annual Meeting of International Society for Ceramics in Medicine, ISCM 2011 -- 6 November 2011 through 9 November 2011 -- Istanbul -- 87411, Hydroxyapatite (HA) is a particularly attractive material for bone and tooth implants since it does not only closely resemble human tooth and bone mineral but it has also biologically proven to be compatible with these tissues. The applications of pure HA are restricted to non load bearing implants due to the poor mechanical properties of HA. Biomaterials of synthetic HA are highly reliable but the synthesis of HA is often complicate and expensive. Bioceramics of naturally derived biological apatites are more economic. Aim of the present work is to introduce sheep teeth dentine HA material as an alternative source of bioactive biomaterials for grafting purposes. The work was started with such a way that extracted sheep teeth were cleaned. The teeth were calcinated at 850°C in air. It was seen that enamel matter was easily separated from dentine after calcination. The collected dentine parts were crushed and ball milled. The powder was pressed between hardened steel dies to produce samples suitable for compression and microhardness tests. The obtained powder compacts were sintered at different temperatures, specifically 1000, 1100, 1200, and 1300°C in air. Results of microhardness and compression strength (along with the statistical analysis of these results) as well as those of SEM and XRD analyses are presented. In the literature, there is very little information about the mechanical properties of dentine and enamel matter derived from sheep, bovine and human. The highest compression strength value in the present study was measured around 146 MPa (from human dentine derived HA the highest value was almost 60 MPa after sintering at 1300°C). The best microhardness in the present study was found as nearly 125 HV. The results of this study showed that the HA material produced from sheep tooth dentine can be qualified as a promising source of HA needed to produce bioactive ceramics. © (2012) Trans Tech Publications, Switzerland.

The Japan Society for the Promotion of Science (JSPS);The Ceramics Society of Japan (CSJ);Engineering Ceramics Division, 4th International Symposium on Advanced Ceramics, ISAC-4 -- 14 November 2010 through 18 November 2010 -- Osaka -- 85716, The aim of this study is to produce and to investigate the mechanical and microstructural properties of composite materials made of hydroxyapatite, obtained from natural bovine bone and nano barium strontium titanium oxide (5 and 10 wt%). Compositions were mechanical alloyed and compacted to pellets. The samples were subjected to sintering at different temperatures between 1000°C and 1300°C. Compression strength, Vickers microhardness as well as density were measured. SEM and X-ray diffraction studies were also conducted. With increasing sintering temperature, microhardness, compression strength and density of composites increased. With increasing addition of nano barium strontium titanium oxide (BST) to bovine hydroxyapatite (BHA), microhardness values of composites decreased at all sintering temperatures, but compression strength and density values of composites showed different tendency. Compression strengths of BHA-composites at low sintering temperatures were nearly the same, but their compression strengths at high sintering temperatures decreased with increasing nano BST addition. The best mechanical properties were obtained at 1300°C sintering temperature with BHA-5wt% nano BST. Microhardness and compression strengths values of these nano-oxide composites are generally higher than that BHA-composites produced by traditional methods. Adding of nano-oxides to BHA could be a valuable method to produce rigid and high load carrying ability when compared with BHA-composites produced by conventional methods. Nano-HA and nano-oxides composites could be even better. Those nano-nano studies are still in progress. © (2011) Trans Tech Publications, Switzerland.

We investigated the possible effects of three pedicular screws on axial pull-out strength in pedicular revision surgery.Two study groups were formed from calf lumbar vertebrae. Initially, Alici pedicular screws with an outer diameter of 6.5 mm were applied (with or without tapping) to all the pedicles. All the pedicles were subjected to axial pull-out testing to induce pedicular insufficiency. Then, Alici pedicular screws with an outer diameter of 7 mm were applied to the left pedicles. The right pedicles in the two study groups were assigned to receive two different types of pedicular screws with an expandable (enlargeable) end, respectively. Axial pull-out testing was repeated in both groups and the results were compared with the initial pull-out strength values.In the first group, 65% and 64% of the initial pull-out strengths were obtained with 7-mm Alici pedicular screws and with expandable pedicular screws, for the left and right pedicles, respectively. The corresponding pull-out strengths in the other study group were 70% and 68.5% of the initial values, respectively. Tapping of the screw hole entrance resulted in a mean decrease of 13% in the pull-out strength compared to screw applications without tapping.Pedicular screw revisions using a 0.5 mm greater screw in diameter did not provide adequate screw-bone inter-face strength and pedicle filling. Similarly, expandable pedicular screws did not contribute to screw stability.