Search results for: implant supported prostheses
491 Evaluation the Distribution of Implant Supported Prostheses between 2005-2009 Years
Abstract:The aim of this retrospective study was to evaluate the parameters of dental implants such as patient gender, number of implant, failed implant before prosthetic restorations and failed implant after implantation and failed implant after prosthetic restorations. 135 male and 99 female patients, total 234 implant patients which have been treated with 450 implant between 2005- 2009 years in GATA Haydarpasa Training Hospital Dental Service. Twelve implants were failed before prosthetic restorations. Four implant were failed after fixed prosthetic restorations. Cumulative survival rate after prostheses were 97.56 % during 6 years period.
Keywords: Dental implants, implant supported prostheses, single implants, single crownProcedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1455
490 A Virtual Electrode through Summation of Time Offset Pulses
Authors: Isaac Cassar, Trevor Davis, Yi-Kai Lo, Wentai Liu
Retinal prostheses have been successful in eliciting visual responses in implanted subjects. As these prostheses progress, one of their major limitations is the need for increased resolution. As an alternative to increasing the number of electrodes, virtual electrodes may be used to increase the effective resolution of current electrode arrays. This paper presents a virtual electrode technique based upon time-offsets between stimuli. Two adjacent electrodes are stimulated with identical pulses with too short of pulse widths to activate a neuron, but one has a time offset of one pulse width. A virtual electrode of twice the pulse width was then shown to appear in the center, with a total width capable of activating a neuron. This can be used in retinal implants by stimulating electrodes with pulse widths short enough to not elicit responses in neurons, but with their combined pulse width adequate to activate a neuron in between them.
Keywords: Electrical stimulation, Neuroprosthesis, Retinal implant, Retinal Prosthesis, Virtual electrode.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1637
489 Placement of Implants in Palatum of a Teenager without Maxillary Incisor Teeth
Authors: Luan Mavriqi, Ilma Robo, Emin Kuzimi, Egresa Baca
The process of skeletal growth in an adolescent significantly affects the displacement of implants placed in the palatine suture. The problems caused by this process have an impact on the dental function and aesthetics of the affected data. If fixed prostheses are placed based on implants, the whole structure would impede maxillary growth. This is the significant difference between the maxilla and the mandible, as the lower jaw has no growth process that affects the movement of the implants or the latter to inhibit the growth of the jaw. In a teenager patient an accident occurred accompanied by loss of maxillary central incisors. The main complaint of patients is aesthetics and phonetics. Dental history of patients refers to the presence of a Maryland bridge that was accompanied by dissatisfaction on the part of the patient. Implant placement is not indicated as jaw augmentation may lead to displacement of the implant. The treatment plan includes the placement of implants in the palatum where this bone thickness allows as a procedure.in this article only the first stage of treatment is presented. Implant treatment is ongoing, will be followed by the second phase of treatment when the patient has reached the age of 18 years.
Keywords: Implants, palatum, adolescent, primary incisor teeth.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 104
488 Design Improvement of Dental Implant-Based on Bone Remodelling
Authors: Solehuddin Shuib, Koay Boon Aik, Zainul Ahmad Rajion
Abstract:There are many types of mechanical failure on the dental implant. In this project, the failure that needs to take into consideration is the bone resorption on the dental implant. Human bone has its ability to remodel after the implantation. As the dental implant is installed into the bone, the bone will detect and change the bone structure to achieve new biomechanical environment. This phenomenon is known as bone remodeling. The objective of the project is to improve the performance of dental implant by using different types of design. These designs are used to analyze and predict the failure of the dental implant by using finite element analysis (FEA) namely ANSYS. The bone is assumed to be fully attached to the implant or cement. Hence, results are then compared with other researchers. The results were presented in the form of Von Mises stress, normal stress, shear stress analysis, and displacement. The selected design will be analyzed further based on a theoretical calculation of bone remodeling on the dental implant. The results have shown that the design constructed passed the failure analysis. Therefore, the selected design is proven to have a stable performance at the recovery stage.
Keywords: Dental implant, FEA, bone remodeling, osseointegration.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 927
487 Bioarm, a Prostheses without Surgery
Authors: J. Sagouis, A. Chamel, E. Carre, C. Casasreales, G. Rudnik, M. Cerdan
Robotics provides answers to amputees. The most expensive solutions surgically connect the prosthesis to nerve endings. There are also several types of non-invasive technologies that recover nerve messages passing through the muscles. After analyzing these messages, myoelectric prostheses perform the desired movement. The main goal is to avoid all surgeries, which can be heavy and offer cheaper alternatives. For an amputee, we use valid muscles to recover the electrical signal involved in a muscle movement. EMG sensors placed on the muscle allows us to measure a potential difference, which our program transforms into control for a robotic arm with two degrees of freedom. We have shown the feasibility of non-invasive prostheses with two degrees of freedom. Signal analysis and an increase in degrees of freedom is still being improved.
Keywords: Prosthesis, electromyography (EMG), robotic arm, nerve message.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1765
486 Design of Hydroxyapatite-Polyetheretherketone Fixation Plates for Diaphysis Femur Fracture
Authors: Abhishek Soni, Bhagat Singh
In this study, scanned data of a damaged femur diaphysis are used to generate three dimensional model of the bone. Further, customized implant of Hydroxyapatite-Polyetheretherketone (HA-PEEK) material for this damaged bone is prepared using CAD modeling. Damaged bone and implant have been assembled to prepare the intact bone. This assembled model has been analyzed to evaluate the stresses and deformation developed during the static loading. It has been observed that these stresses and deformation are very less thus imply that the proposed method of preparing implant is appropriate.
Keywords: Customized implant, deformation, femur diaphysis, stress.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 414
485 Effects of Thread Dimensions of Functionally Graded Dental Implants on Stress Distribution
Authors: Kaman M. O., Celik N.
Abstract:In this study, stress distributions on dental implants made of functionally graded biomaterials (FGBM) are investigated numerically. The implant body is considered to be subjected to axial compression loads. Numerical problem is assumed to be 2D, and ANSYS commercial software is used for the analysis. The cross section of the implant thread varies as varying the height (H) and the width (t) of the thread. According to thread dimensions of implant and material properties of FGBM, equivalent stress distribution on the implant is determined and presented with contour plots along with the maximum equivalent stress values. As a result, with increasing material gradient parameter (n), the equivalent stress decreases, but the minimum stress distribution increases. Maximum stress values decrease with decreasing implant radius (r). Maximum von Mises stresses increases with decreasing H when t is constant. On the other hand, the stress values are not affected by variation of t in the case of H = constant.
Keywords: Functionally graded biomaterials, dental implant finite element method.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2904
484 Neural Networks for Distinguishing the Performance of Two Hip Joint Implants on the Basis of Hip Implant Side and Ground Reaction Force
Authors: L. Parisi
In this research work, neural networks were applied to classify two types of hip joint implants based on the relative hip joint implant side speed and three components of each ground reaction force. The condition of walking gait at normal velocity was used and carried out with each of the two hip joint implants assessed. Ground reaction forces’ kinetic temporal changes were considered in the first approach followed but discarded in the second one. Ground reaction force components were obtained from eighteen patients under such gait condition, half of which had a hip implant type I-II, whilst the other half had the hip implant, defined as type III by Orthoload®. After pre-processing raw gait kinetic data and selecting the time frames needed for the analysis, the ground reaction force components were used to train a MLP neural network, which learnt to distinguish the two hip joint implants in the abovementioned condition. Further to training, unknown hip implant side and ground reaction force components were presented to the neural networks, which assigned those features into the right class with a reasonably high accuracy for the hip implant type I-II and the type III. The results suggest that neural networks could be successfully applied in the performance assessment of hip joint implants.
Keywords: Kinemic gait data, Neural networks, Hip joint implant, Hip arthroplasty, Rehabilitation Engineering.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1668
483 Optimization of HALO Structure Effects in 45nm p-type MOSFETs Device Using Taguchi Method
Authors: F. Salehuddin, I. Ahmad, F. A. Hamid, A. Zaharim, H. A. Elgomati, B. Y. Majlis, P. R. Apte
In this study, the Taguchi method was used to optimize the effect of HALO structure or halo implant variations on threshold voltage (VTH) and leakage current (ILeak) in 45nm p-type Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) device. Besides halo implant dose, the other process parameters which used were Source/Drain (S/D) implant dose, oxide growth temperature and silicide anneal temperature. This work was done using TCAD simulator, consisting of a process simulator, ATHENA and device simulator, ATLAS. These two simulators were combined with Taguchi method to aid in design and optimize the process parameters. In this research, the most effective process parameters with respect to VTH and ILeak are halo implant dose (40%) and S/D implant dose (52%) respectively. Whereas the second ranking factor affecting VTH and ILeak are oxide growth temperature (32%) and halo implant dose (34%) respectively. The results show that after optimizations approaches is -0.157V at ILeak=0.195mA/μm.
Keywords: Optimization, p-type MOSFETs device, HALO Structure, Taguchi Method.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1912
482 Mechanical Evaluation of Stainless Steel and Titanium Dynamic Hip Screws for Trochanteric Fracture
Authors: Supakit Rooppakhun, Nattapon Chantarapanich, Bancha Chernchujit, Banchong Mahaisavariya, Sedthawatt Sucharitpwatskul, Kriskrai Sitthiseripratip
Abstract:This study aimed to present the mechanical performance evaluation of the dynamic hip screw (DHS) for trochanteric fracture by means of finite element method. The analyses were performed based on stainless steel and titanium implant material definitions at various stages of bone healing and including implant removal. The assessment of the mechanical performance used two parameters, von Mises stress to evaluate the strength of bone and implant and elastic strain to evaluate fracture stability. The results show several critical aspects of dynamic hip screw for trochanteric fracture stabilization. In the initial stage of bone healing process, partial weight bearing should be applied to avoid the implant failure. In the late stage of bone healing, stainless steel implant should be removed.
Keywords: Trochanteric fracture, Dynamic hip screw (DHS), Finite element analysis.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2710
481 Effect of Runup over a Vertical Pile Supported Caisson Breakwater and Quarter Circle Pile Supported Caisson Breakwater
Authors: T. J. Jemi Jeya, V. Sriram
Pile Supported Caisson breakwater is an ecofriendly breakwater very useful in coastal zone protection. The model is developed by considering the advantages of both caisson breakwater and pile supported breakwater, where the top portion is a vertical or quarter circle caisson and the bottom portion consists of a pile supported breakwater defined as Vertical Pile Supported Breakwater (VPSCB) and Quarter-circle Pile Supported Breakwater (QPSCB). The study mainly focuses on comparison of run up over VPSCB and QPSCB under oblique waves. The experiments are carried out in a shallow wave basin under different water depths (d = 0.5 m & 0.55 m) and under different oblique regular waves (00, 150, 300). The run up over the surface is measured by placing two run up probes over the surface at 0.3 m on both sides from the centre of the model. The results show that the non-dimensional shoreward run up shows slight decrease with respect to increase in angle of wave attack.
Keywords: Caisson breakwater, pile supported breakwater, quarter circle breakwater, vertical breakwater.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 505
480 Attenuation in Transferred RF Power to a Biomedical Implant due to the Misalignment Coils
Authors: Batel Noureddine, Mehenni Mohamed, Dekar Lies
Abstract:In biomedical implant field, a new formula is given for the study of Radio Frequency power attenuation by simultaneous effects of side and angular misalignment of the supply/data transfer coils. A confrontation with the practical measurements done into a Faraday cage, allowed a checking of the obtained theoretical results. The DC supply systems without material connection and the data transmitters used in the case of biomedical implants, can be well dimensioned by taking into account the possibility of power attenuation by misalignment of transfer coils
Keywords: Biomedical implant field, misalignment coils, powerattenuation, transmitter and receiver coils.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1574
479 Modeling of Cobalt-Chromium-Molybdenum Alloy Implant for Fractured Distal Femur
Authors: Abhishek Soni, Bhagat Singh
Distal femur fractures are the cause of abnormal gloomy. Several types of surgical treatments have been adopted by the practitioners to restore the fractured region of distal femur. Still within this domain of study, unstable fixation remains a challenge for orthopedists. In the present study, a fixation implant is designed and analyzed under physiological loading conditions for cobalt-chromium-molybdenum alloy (Co-Cr-Mo). It has been found that the stresses and deformation developed are quite low. It means that customized fixation plates will provide stable fixation resulting in improved fracture union.
Keywords: Biomechanical evaluations, customized implant, Co-Cr-Mo alloy, reverse engineering.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 541
478 Host Responses in Peri-Implant Tissue in Comparison to Periodontal Tissue
Authors: Raviporn Madarasmi, Anjalee Vacharaksa, Pravej Serichetaphongse
The host response in peri-implant tissue may differ from that in periodontal tissue in a healthy individual. The purpose of this study is to investigate the expression of inflammatory cytokines in peri-implant crevicular fluid (PICF) from single implant with different abutment types in comparison to healthy periodontal tissue. 19 participants with healthy implants and teeth were recruited according to inclusion and exclusion criteria. PICF and gingival crevicular fluid (GCF) was collected using sterile paper points. The expression level of inflammatory cytokines including IL-1α, IL-1β, TNF-α, IFN-γ, IL-6, and IL-8 was assessed using enzyme-linked immunosorbent assay (ELISA). Paired t test was used to compare the expression levels of inflammatory cytokines around natural teeth and peri-implant in PICF and GCF of the same individual. The Independent t-test was used to compare the expression levels of inflammatory cytokines in PICF from titanium and UCLA abutment. Expression of IL-6, TNF-α, and IFN-γ in PICF was not statistically different from GCF among titanium and UCLA abutment group. However, the level of IL-1α in the PICF from the implants with UCLA abutment was significantly higher than GCF (P=0.030). In addition, the level of IL-1β in PICF from the implants with titanium abutment was significantly higher than GCF (P=0.032). When different abutment types was compared, IL-8 expression in PICF from implants with UCLA abutment was significantly higher than titanium abutment (P=0.003).
Keywords: Abutment, dental implant, gingival crevicular fluid and peri-implant crevicular fluid.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 810
477 Pattern Recognition Based Prosthesis Control for Movement of Forearms Using Surface and Intramuscular EMG Signals
Authors: Anjana Goen, D. C. Tiwari
Myoelectric control system is the fundamental component of modern prostheses, which uses the myoelectric signals from an individual’s muscles to control the prosthesis movements. The surface electromyogram signal (sEMG) being noninvasive has been used as an input to prostheses controllers for many years. Recent technological advances has led to the development of implantable myoelectric sensors which enable the internal myoelectric signal (MES) to be used as input to these prostheses controllers. The intramuscular measurement can provide focal recordings from deep muscles of the forearm and independent signals relatively free of crosstalk thus allowing for more independent control sites. However, little work has been done to compare the two inputs. In this paper we have compared the classification accuracy of six pattern recognition based myoelectric controllers which use surface myoelectric signals recorded using untargeted (symmetric) surface electrode arrays to the same controllers with multichannel intramuscular myolectric signals from targeted intramuscular electrodes as inputs. There was no significant enhancement in the classification accuracy as a result of using the intramuscular EMG measurement technique when compared to the results acquired using the surface EMG measurement technique. Impressive classification accuracy (99%) could be achieved by optimally selecting only five channels of surface EMG.
Keywords: Discriminant Locality Preserving Projections (DLPP), myoelectric signal (MES), Sparse Principal Component Analysis (SPCA), Time Frequency Representations (TFRs).Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1219
476 Laser Welded Ni-Cr Dental Alloys Inspection
Authors: Porojan S., Sandu L., Topală F.
Abstract:Minor problems arising from optimizations by welding of fixed prostheses frameworks can be identified by macroscopic and microscopic visual inspection. The purpose of this study was to highlight the visible discontinuities present in the laser welds of dental Ni-Cr alloys. Ni-Cr base metal alloys designated for fixed prostheses manufacture were selected for the experiments. Using cast plates, preliminary tests were conducted by laser welding. Macroscopic visual inspection was done carefully to assess the defects of the welding rib. Electron microscopy images allowed visualization of small discontinuities, which escapes visual inspection. Making comparison to Ni-Cr alloys taken in the experiment and laser welded, after visual analysis, the best welds appear for Heraenium NA alloy.
Keywords: macroscopic visual inspection, electron microscopyimages, Ni-Cr dental alloys, laser welding.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1413
475 Design of Stainless Steel Implant for Fractured Distal Femur
Authors: Abhishek Soni, Bhagat Singh
Perfect restoration of fractured distal femur has been a challenging task for the medical practitioners. In the present study, model of a fractured bone has been created using the scan data of the damaged bone. Thereafter, customized implant of Stainless Steel (SS-316L) for this fractured femur bone is modeled using the reverse engineering approach. Clinical set-up is prepared by assembling all the models together. Stress and deformation analysis of this clinical set-up has been performed in order to check the load bearing capacity and intactness of the joint. From this analysis, it has been inferred that the stresses and deformation developed due to the static load of the person is within the permissible limits.
Keywords: Biomechanical evaluations, customized implant, reverse engineering, stainless steel alloy.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 575
474 Process Optimization Regarding Geometrical Variation and Sensitivity Involving Dental Drill- and Implant-Guided Surgeries
Authors: T. Kero, R. Söderberg, M. Andersson, L. Lindkvist
Abstract:Within dental-guided surgery, there has been a lack of analytical methods for optimizing the treatment of the rehabilitation concepts regarding geometrical variation. The purpose of this study is to find the source of the greatest geometrical variation contributor and sensitivity contributor with the help of virtual variation simulation of a dental drill- and implant-guided surgery process using a methodical approach. It is believed that lower geometrical variation will lead to better patient security and higher quality of dental drill- and implant-guided surgeries. It was found that the origin of the greatest contributor to the most variation, and hence where the foci should be set, in order to minimize geometrical variation was in the assembly category (surgery). This was also the category that was the most sensitive for geometrical variation.
Keywords: Variation Simulation, Process Optimization, Guided Surgeries, Dental Prosthesis.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1165
473 Retaining Users in a Commercially-Supported Social Network
Authors: Sasiphan Nitayaprapha
A commercially-supported social network has become an emerging channel for an organization to communicate with and provide services to customers. The success of the commercially-supported social network depends on the ability of the organization to keep the customers in participating in the network. Drawing from the theories of information adoption, information systems continuance, and web usability, the author develops a model to explore how a commercially-supported social network can encourage customers to continue participating and using the information in the network. The theoretical model will be proved through an online survey of customers using the commercially-supported social networking sites of several high technology companies operating in the same sector. The result will be compared with previous studies to learn about the explanatory power of the research model, and to identify the main factors determining users’ intention to continue using a commercially-supported social network. Theoretical and practical implications and limitations are discussed.
Keywords: Social network, Information adoption, Information systems continuance, Web usability, User satisfaction.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1767
472 Adherence of Alveolar Fibroblasts and Microorganisms on Titanium Implants
Authors: J. Franková, V. Pivodová, F. Růžička, J. Ulrichová
Abstract:An implant elicits a biological response in the surrounding tissue which determines the acceptance and long-term function of the implant. Dental implants have become one of the main therapy methods in clinic after teeth lose. A successful implant is in contact with bone and soft tissue represent by fibroblasts. In our study we focused on the interaction between six different chemically and physically modified titanium implants (Tis-MALP, Tis-O, Tis- OA, Tis-OPAAE, Tis-OZ, Tis-OPAE) with alveolar fibroblasts as well as with five type of microorganisms (S. epidermis, S.mutans, S. gordonii, S. intermedius, C.albicans). The analysis of microorganism adhesion was determined by CFU (colony forming unite) and biofilm formation. The presence of α3β1 and vinculin expression on alveolar fibroblasts was demonstrated using phospho specific cell based ELISA (PACE). Alveolar fibroblasts have the highest expression of these proteins on Tis-OPAAE and Tis-OPAE. It corresponds with results from bacterial adhesion and biofilm formation and it was related to the lowest production of collagen I by alveolar fibroblasts on Tis-OPAAE titanium disc.
Keywords: titanium disc, alveolar fibroblasts, microorganisms, adhesionProcedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1372
471 Attenuation in Transferred RF Power to a Biomedical Implant due to the Absorption of Biological Tissue
Authors: Batel Noureddine, Mehenni Mohamed, Kouadik Smain
Abstract:In a transcutanious inductive coupling of a biomedical implant, a new formula is given for the study of the Radio Frequency power attenuation by the biological tissue. The loss of the signal power is related to its interaction with the biological tissue and the composition of this one. A confrontation with the practical measurements done with a synthetic muscle into a Faraday cage, allowed a checking of the obtained theoretical results. The supply/data transfer systems used in the case of biomedical implants, can be well dimensioned by taking in account this type of power attenuation.
Keywords: Biological tissue, coupled coils, implanted device, power attenuation.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2202
470 Semiconductor Supported Gold Nanoparticles for Photodegradation of Rhodamine B
Authors: Ahmad Alshammari, Abdulaziz Bagabas
Rhodamine B (RB) is a toxic dye used extensively in textile industry, which must be remediated before its drainage to environment. In the present study, supported gold nanoparticles on commercially available titania and zincite were successfully prepared and then their activity on the photodegradation of RB under UV A light irradiation were evaluated. The synthesized photocatalysts were characterized by ICP, BET, XRD, and TEM. Kinetic results showed that Au/TiO2 was an inferior photocatalyst to Au/ZnO. This observation could be attributed to the strong reflection of UV irradiation by gold nanoparticles over TiO2 support.
Keywords: Supported AuNPs, Semiconductor photocatalyst, Photodegradation, Rhodamine B.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2167
469 Modeling of Titanium Alloy Implant for Fractured Distal Femur
Authors: Abhishek Soni, Bhagat Singh
Abstract:In the present work, reverse engineering (RE) approach has been used to create a 3D model of a fractured femur bone using the computed tomography (CT) scan data. Thereafter, counter fit fixation plates of Titanium alloy (Ti6Al4V) have been designed and analyzed considering physiological static loading conditions. From the analysis, it has been inferred that the stresses and deformation developed are quite low. It implies that these designed customized fixation plates are able to provide stable fixation resulting in improved fracture union.
Keywords: Biomechanical evaluations, customized implant, reverse engineering, titanium alloy.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 528
468 Biodiesel Production from Soybean Oil over TiO2 Supported nano-ZnO
Authors: Mbala Mukenga, Edison Muzenda, Kalala Jalama, Reinout Meijboom
Abstract:TiO2 supported nano-ZnO catalyst was prepared by deposition-precipitation and tested for the trans-esterification reaction of soybean oil to biodiesel. The TiO2 support stabilized the nano-ZnO in a dispersed form with limited crystallite size compared to the unsupported ZnO. The final ZnO dispersion and crystallite size and the material transfer resistance in the catalyst significantly influenced the supported nano-ZnO catalyst performance.
Keywords: nano-ZnO, soybean oil, TiO2, trans-esterificationProcedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1876
467 The Clinical Use of Ahmed Valve Implant as an Aqueous Shunt for Control of Uveitic Glaucoma in Dogs
Authors: Khaled M. Ali, M. A. Abdel-Hamid, Ayman A. Mostafa
Abstract:Objective: Safety and efficacy of Ahmed glaucoma valve implantation for the management of uveitis induced glaucoma evaluated on the five dogs with uncontrollable glaucoma. Materials and Methods: Ahmed Glaucoma Valve (AGV®; New World Medical, Rancho Cucamonga, CA, USA) is a flow restrictive, nonobstructive self-regulating valve system. Preoperative ocular evaluation included direct ophthalmoscopy and measurement of the intraocular pressure (IOP). The implant was examined and primed prior to implantation. The selected site of the valve implantation was the superior quadrant between the superior and lateral rectus muscles. A fornix-based incision was made through the conjunectiva and Tenon’s capsule. A pocket is formed by blunt dissection of Tenon’s capsule from the episclera. The body of the implant was inserted into the pocket with the leading edge of the device around 8-10 mm from the limbus. Results: No post-operative complications were detected in the operated eyes except a persistent corneal edema occupied the upper half of the cornea in one case. Hyphaema was very mild and seen only in two cases which resolved quickly two days after surgery. Endoscopical evaluation for the operated eyes revealed a normal ocular fundus with clearly visible optic papilla, tapetum and retinal blood vessels. No evidence of hemorrhage, infection, adhesions or retinal abnormalities was detected. Conclusion: Ahmed glaucoma valve is safe and effective implant for treatment of uveitic glaucoma in dogs.
Keywords: Ahmed valve, endoscopy, glaucoma, ocular fundus.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1885
466 Global and Local Structure of Supported Pd Catalysts
Authors: V. Rednic, N. Aldea, P. Marginean, D. Macovei, C. M. Teodorescu, E. Dorolti, F. Matei
Abstract:The supported Pd catalysts were analyzed by X-ray diffraction and X-ray absorption spectroscopy in order to determine their global and local structure. The average particle size of the supported Pd catalysts was determined by X-ray diffraction method. One of the main purposes of the present contribution is to focus on understanding the specific role of the Pd particle size determined by X-ray diffraction and that of the support oxide. Based on X-ray absorption fine structure spectroscopy analysis we consider that the whole local structure of the investigated samples are distorted concerning the atomic number but the distances between atoms are almost the same as for standard Pd sample. Due to the strong modifications of the Pd cluster local structure, the metal-support interface may influence the electronic properties of metal clusters and thus their reactivity for absorption of the reactant molecules.
Keywords: metal-support interaction, supported metal catalysts, synchrotron radiation, X-ray absorption spectroscopy, X-raydiffractionProcedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1409
465 Mathematical Modeling on Capturing of Magnetic Nanoparticles in an Implant Assisted Channel for Magnetic Drug Targeting
Authors: Shashi Sharma, V. K. Katiyar, Uaday Singh
Abstract:In IA-MDT, the magnetic implants are placed strategically at the target site to greatly and locally increase the magnetic force on MDCPs and help to attract and retain the MDCPs at the targeted region. In the present work, we develop a mathematical model to study the capturing of magnetic nanoparticles flowing within a fluid in an implant assisted cylindrical channel under magnetic field. A coil of ferromagnetic SS-430 has been implanted inside the cylindrical channel to enhance the capturing of magnetic nanoparticles under magnetic field. The dominant magnetic and drag forces, which significantly affect the capturing of nanoparticles, are incorporated in the model. It is observed through model results that capture efficiency increases as we increase the magnetic field from 0.1 to 0.5 T, respectively. The increase in capture efficiency by increase in magnetic field is because as the magnetic field increases, the magnetization force, which is attractive in nature and responsible to attract or capture the magnetic particles, increases and results the capturing of large number of magnetic particles due to high strength of attractive magnetic force.
Keywords: Capture efficiency, Implant assisted-Magnetic drug targeting (IA-MDT), Magnetic nanoparticles (MNPs).Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1651
464 Carbon Supported Cu and TiO2 Catalysts Applied for Ozone Decomposition
Authors: Katya Milenova, Penko Nikolov, Irina Stambolova, Plamen Nikolov, Vladimir Blaskov
In this article a comparison was made between Cu and TiO2 supported catalysts on activated carbon for ozone decomposition reaction. The activated carbon support in the case of TiO2/AC sample was prepared by physicochemical pyrolysis and for Cu/AC samples the supports are chemically modified carbons. The prepared catalysts were synthesized by impregnation method. The samples were annealed in two different regimes- in air and under vacuum. To examine adsorption efficiency of the samples BET method was used. All investigated catalysts supported on chemically modified carbons have higher specific surface area compared to the specific surface area of TiO2 supported catalysts, varying in the range 590÷620 m2/g. The method of synthesis of the precursors had influenced catalytic activity.
Keywords: Activated carbon, adsorption, copper, ozone decomposition, TiO2.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2528
463 Selective and Facilitated Transport of Vanadium (VO2 +) Ion through Supported Liquid Membrane and Effects of Membrane Characteristics
Authors: Danial Husseinzadeh
Abstract:A new supported liquid membrane (SLM) system for the selective transport of VO2 + ions was prepared in this present work. The SLM was a thin porous polyvinylidene difluoride (PVDF) membrane soaked with Di-(2-ethylhexyl) phosphoric acid (D2EHPA) as mobile carrier in Xylene as organic solvent. D2EHPA acts as a highly selective carrier for the uphill transport of VO2 + ions through the SLM. The transport of VO2 + ions reached to 64%. In the presence of P2O7-2 ion as suitable masking agent in the feed solution, the interfering effects of other cations were eliminated.
Keywords: Facilitated ion transport, Membrane characteristics, Supported liquid membranes, Vanadium.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1719
462 Design of Polyetheretherketone Fixation Plates for Fractured Distal Femur
Authors: Abhishek Soni, Bhagat Singh
In the present study, a methodology has been proposed to treat fracture in the distal part of the femur bone. Initially, bone model has been developed using the computed tomography scan data of the fractured bone. This information has been further used to create polyether ether ketone (PEEK) implant for this fractured bone. Damaged bone and implant models have been assembled. This assembled model has been further analyzed for stress distribution. Moreover, deformation developed was also measured. It has been observed that the stress and deformation developed was not so appreciable. Thus, it proves that the aforementioned procedure can be suitably adopted for the treatment of fractured distal femur bone.
Keywords: Distal femur, fixation plates, PEEK, reverse engineering.Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 313