Influencia del tiempo disponible y usado en un examen online sobre la nota obtenida

[ES] El uso de herramientas online en el proceso educativo de los alumnos universitarios es ya algo habitual. No obstante, muchos de los profesores actuales terminaron sus estudios cuando esta tecnología estaba, en el mejor de los casos, en ciernes. Esto hace que los profesores no dispongan de un conocimiento adecuado sobre cuál es el comportamiento de los alumnos ante los contenidos y herramientas disponibles en internet, lo que dificulta hacer de ellas el uso más adecuado posible. Los exámenes online es una de las herramientas que más puede facilitar el trabajo de un docente ya que facilita la corrección de los mismos y permite dar al estudiante una evaluación continua de su progreso. En este trabajo se estudia cual es el efecto de ampliar el tiempo disponible para hacer un examen online de tipo test y qué relación hay entre las notas obtenidas y el tiempo empleado para terminar los exámenes, ya sean de tipo test o consistan en resolver un problema[EN] The use of online tools in the educational process of university students is already common. However, many of the current teachers finished their studies when this technology was, at best, budding. This makes it difficult for the teachers to have an adequate knowledge of what the student's behavior regarding the contents and tools available online is, what hinders making the most profitable use of online tools. Online exams are one of the most useful tools to ease the work of a teacher because it facilitates the correction of the exams and offers the opportunity of giving the student a continuous evaluation of his progress. In this report, we study the effect of extending the available time to complete an online test and what is the relation between the time used to finish the tests and the obtained marks for test exams and for problem-solving examSalas Vicente, F.; Vicente-Escuder, Á. (2019). Influencia del tiempo disponible y usado en un examen online sobre la nota obtenida. Universitat Politècnica de València. 381-389. http://hdl.handle.net/10251/179359S38138

Mechanical properties of duplex stainless steel laser joints

[EN] This work presents the influence of welding parameters on the microstructural parameters and mechanical behaviour of welded joints. In doing so, we seek to establish the microstructural changes in the molten area and the heat affected zone, which will define the mechanical properties of the welded joints. This mechanical behaviour is evaluated by means of traction tests on welded test pieces and microhardness scanning of the heat affected zone.The authors would like to express their gratitude to the Asociación de Investigación de Óptica de la Comunidad Valenciana [Community of Valencia Optics Research Association] for the application of the laser welds and to the Spanish Ministry of Science and Technology for its support through Project MAT2001-1123-C03-02.Amigó, V.; Bonache Bezares, V.; Teruel Biosca, L.; Vicente-Escuder, Á. (2006). Mechanical properties of duplex stainless steel laser joints. Welding International. 20(5):361-366. doi:10.1533/wint.2006.3582S36136620

Fatigue behaviour of GMAW welded aluminium alloy AA7020

[EN] The aim of this investigation is to evaluate the influence on fatigue behaviour of the finishing of the bulge in a welded aluminium zinc magnesium alloy AA7020. It was determined that total or partial elimination of the bulge has very little influence on its behaviour, giving a very similar result on both cases, where one is better than the other by only 3%.Bloem, C.; Salvador Moya, MD.; Amigó, V.; Vicente-Escuder, Á. (2009). Fatigue behaviour of GMAW welded aluminium alloy AA7020. Welding International. 23(10):111-116. doi:10.1080/09507110902843321S111116231

Analysis of fit on implants of chrome cobalt versus titanium frameworks made by cad / cam milling

This study analyzed the degree of passive and vertical fit achieved in frameworks using either cobalt-chromium (Co-Cr) or titanium (Ti) implant-supported fixed partial dentures ( FPDs) fabricated with a CAD/CAM milling technique. 33 3-unit FDPs, 17 of Co-Cr metal alloy (test group) and 16 of Ti (control group), were manufactured with two implants by copy milled technology. Optical microscopy was used to measure passive fit (PF) and vertical fit (VF) in all frameworks. The PF was evaluated by using the Single Screw test and the VF with the screws tightened at 20 Ncm. Descriptive and inferential analysis were performed to evaluate statistically significant differences in the tested groups for each fit. Brunner-Langer models were applied to assess potential material and implant area effects on the measurements. An ANOVA test was performed to estimate both main effects and interactions. The average PF values in the screwed implant were 4.43 ± 0.52 µm for Ti and 5.50 ± 1.61 µm for Co-Cr and in the non-screwed implant 5.59 ± 1.32 µm in the group Ti and 6.25 ± 1.55 µm the Co-Cr group. In this last implant, it was not observed statistically significant differences between both types of alloy (p = 0.178) nor between zones. Ti control group exhibited a significantly better VF than Co-Cr (p = 0.046) in the screwed implant but there were no differences in the implant not screwed. The VF in the non-screwed implant was better in lingual than in buccal zone. The PF and VF measurements observed in Co-Cr frameworks are clinically acceptable. 3-unit implant supported FPDs made with Co-Cr alloy using milling technique showed similar dimensional accuracy than those obtained with Ti

Effect on Procrastination and Learning of Mistakes in the Design of the Formative and Summative Assessments - A Case Study

[EN] The design of the formative and summative assessment processes is of paramount importance to help students avoid procrastination and guide them towards the achievement of the learning objectives that are described in the course syllabus. If the assessment processes are poorly designed the outcome can be disappointing, including high grades but poor learning. In this paper, we describe the unexpected and undesirable effects that an on-demand formative assessment and the timetable of a summative assessment that left the most cognitively demanding part, problem-solving, to the end of the course, had on the behavior of students and on both grading and learning. As the formative assessment was voluntary, students procrastinated till the last minute. However, the real problem was that due to the design of the summative assessment, they focused their efforts mainly on the easiest parts of the summative assessment, passing the course with ease, but achieving a low learning level, as evidenced by the low scores of the problem-solving part of the summative assessment.Salas Vicente, F.; Vicente-Escuder, Á.; Pérez Puig, MA.; Segovia-López, F. (2021). Effect on Procrastination and Learning of Mistakes in the Design of the Formative and Summative Assessments - A Case Study. Education Sciences. 11(8):1-12. https://doi.org/10.3390/educsci11080428S11211

Study of Electrochemical and Biological Characteristics of As-Cast Ti-Nb-Zr-Ta System Based on Its Microstructure

[EN] The quaternary Ti-Nb-Zr-Ta (TNZT) alloy was successfully cast-fabricated with the objective to be used in the medical field. Samples' microstructure was compared to CP-Ti and Ti-6Al-4V (control samples) and related to corrosion, ion release and biological properties. As-cast TNZT was formed with large grain sizes (285 m) compared to the ultrafine grain sizes of CP-Ti (11 m) and the + ultrafine grain sizes of 1.45 m and 0.74 m. Hardness and flexural elastic moduli (94 HV and 43 GPa) came close to the biological structures, such as dentin and enamel values. The ion release mechanism of as-cast TNZT was significantly lesser than CP-Ti and Ti-6Al-4V, which can be related to the difference in samples¿ grain sizes and chemical compositions. However, the corrosion rate was higher than for the control samples; this way offers corrosion properties inferior with respect to the properties obtained in the reference materials. Biological assays demonstrated that the two-cell (hDPSCs and MG-63) lineage studied presented good adhesion and capability to differentiate in bone cells on the as-cast TNZT surface, and no cytotoxicity effects were found. Details and reasons based on samples¿ microstructure are discussed.The authors thank the Spanish Ministerio de Economia y Competitividad for Research Project RTI2018-097810-B-I00 and the European Commission for FEDER funds.Correa Rossi, M.; Navarro, B.; Milian Medina, L.; Vicente-Escuder, Á.; Amigó, V. (2022). Study of Electrochemical and Biological Characteristics of As-Cast Ti-Nb-Zr-Ta System Based on Its Microstructure. Metals. 12(3):1-25. https://doi.org/10.3390/met1203047612512

Corrosion behaviour of Ti6Al4V ELI nanotubes for biomedical applications

[EN] Surfaces engineering on titanium biomedical alloys aiming for improving bone regeneration, healing periods and increasing lifetime needs fora fundamental understanding of the electrochemical reactions occurring at the interface biomaterial/human fluid. There, electrochemical corrosion plays an important role in implant-tissue interaction. The aim of this study is to investigate the effect of different TiO2 surfaces and nanotubes on a Ti6Al4V ELI in their electrochemical corrosion resistance by different electrochemical techniques (open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization). The electrochemical behaviour of native, anodized, nanotubular and annealed nanotubular surfaces were investigated in 1 M NaCl solution. The nanotubular topography was obtained by electrochemical oxidation and the annealing treatment allowed at changing the crystalline structure of the oxides. The nanotube morphology, chemical composition, and structure was studied by Field Emission Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-ray diffraction and Transmission Electron Microscopy respectively. The results show that the anodic oxidation treatment creates a nanotubular topography that increases the surface area and changes the surface chemical composition. The electrochemical corrosion resistance decreased on the as-formed TiO2 tubes compared to the native oxide layer, due to higher surface area and amorphous crystal structure of the passive film. After annealing treatment, the fluoride ions are eliminated, and nanotubular resistance is enhanced through anatase stabilization.The authors wish to thank the Spanish Ministry of Economy and Competitiveness for the financial support of Research Project MAT2014-53764-C3-1-R, the Generalitat Valenciana for support through PROMETEO 2016/040, and the European Commission via FEDER funds to purchase equipment for research purposes and the Microscopy Service at the Valencia Polytechnic University. Thanks to Alba Dalmau and Javier Navarro Laboulais from Instituto de Seguridad Industrial y Medio Ambiente, Valencia Polytechnic University for the technical assistance with preparation of the electrochemical tests. Thanks to Irene Llorente and Jose Antonio Jimenez from CENIM/CSIC for the technical assistance with XRD characterization.Lario, J.; Viera, M.; Vicente-Escuder, Á.; Igual Muñoz, AN.; Amigó, V. (2019). Corrosion behaviour of Ti6Al4V ELI nanotubes for biomedical applications. Journal of Materials Research and Technology. 8(6):5548-5556. https://doi.org/10.1016/j.jmrt.2019.09.023S554855568

Performance of Ti-15Mo alloy obtained by powder metallurgy route weakly alloyed with Fe/Cr elements

[EN] Ti-15Mo alloy can be an excellent choice as a biomaterial for prostheses. This is due to the combination of good mechanical properties and biocompatibility. The Mo is a stabilizing element of the ß phase, which provides a smaller elastic modulus, reducing the risk of stress shielding that induces bone resorption. The present work shows the effect of minor additions of Fe or Cr on flexural fracture toughness in Ti-15Mo alloys obtained by Powder Metallurgy. The electrochemical results indicated that the Ti-15Mo-1Cr, showed greater resistance to corrosion, related to lower ß grain size, less porosity content compared to the other conditions. As the Ti-15Mo-1Fe and Ti-15Mo-3Fe presented more porosity in their microstructure, the saline composition inside the pores is different in concentration and thus makes diffusion difficult compared to other regular and more homogeneous zones. Besides, was verified the effect of the large grain size that decrease the corrosion resistance of the Ti-15Mo-3Cr, demonstrated two influences in the corrosion resistance, porosity and grain size. Toughness decreases with the addition of both elements, more pronounced with Fe than Cr. It is related with lower densification, higher porosity and greater proportion of phase ¿ in grain boundary due to the higher resistance of diffusion of Mo in Ti when Fe is present, which leads to failure by brittle fracture at lower shear stresses.Correa Rossi, M.; López Navarro, P.; Vicente-Escuder, Á.; Amigó, V.; Segovia-López, F. (2022). Performance of Ti-15Mo alloy obtained by powder metallurgy route weakly alloyed with Fe/Cr elements. Social Science Research Network. 1-28. https://doi.org/10.2139/ssrn.400776212

Effect of Alloying Elements on Laser Surface Modification of Powder Metallurgy to Improve Surface Mechanical Properties of Beta Titanium Alloys for Biomedical Application

[Abstract] Beta-type titanium alloy surfaces (Tie35Nbe10Ta (TNT) and Tie30Nbe4Sn (TNS)) weremodified by laser using a power of 1000 W and speed of 6.7 mm/s (Condition A) and a powerof 1500 W with speed of 10 mm/s (Condition B). Increasing laser conditions, the thicknessof the molten layer was also increased. The initial equiaxed grains changes to quiteelongated grains shape. The surfaces were structured undera00martensite,aand matrixb.Thebphase content decreased slightly and thea00phase increased for both alloysincreasing the laser conditions. The condition A increased the elastic modulus (E) anddecreased the hardness while condition B did not affect the mechanical properties surfacefor the TNT system compared to base metal (BM). In TNS system the laser condition Adecreased the E and increased the hardness while increasing the laser parameters (Con-dition B) both E and hardness decreased compared to BM. The laser surface treatment wasinfluenced by the levels of alloying elements present promoting most significant changesin the microstructure and mechanical properties in the TNS systemThis work was supported by the Ministerio Español de Ciencia, Innovación y Universidades, Spain with Grant RTI2018-097810-B-I00, RTI2018-096472-B-I00 and the European Union (EU) through Fondo Europeo de Desarrollo Regional (FEDER), Spai

Influence of Heat Treatment and UV Irradiation on the Wettability of Ti35Nb10Ta Nanotubes

[EN] The implant osseointegration rate depends on the surface¿s topography and chemical composition. There is a growing interest in the anodic oxidation process to obtain an oxide layer with a nanotube morphology on beta titanium alloys. This surface treatment presents large surface area, nanoscale rugosity and electrochemical properties that may increase the biocompatibility and osseointegration rate in titanium implants. In this work, an anodic oxidation process was used to modify the surface on the Ti35Nb10Ta alloy to obtain a titanium nanotubes topography. The work focused on analyzing the influence of some variables (voltage, heat treatment and ultraviolet irradiation) on the wettability performance of a titanium alloy. The morphology of the nanotubes surfaces was studied by Field Emission Scanning Electron Microscopy (FESEM), and surface composition was analyzed by Energy Dispersive Spectroscopy (EDS). The measurement of contact angle for the TiO2 nanotube surfaces was measured by a video contact angle system. The surface with the non photoinduced nanotubes presented the largest contact angles. The post-heat treatment lowered the F/Ti ratio in the nanotubes and decreased the contact angle. Ultraviolet (UV) irradiation of the TiO2 nanotubes decrease the water contact angle.The authors wish to thank the Spanish Ministry of Economy and Competitiveness for the financially supportting Research Project MAT2014-53764-C3-1-R, the Generalitat Valenciana for support through PROMETEO 2016/040, the European Commission for FEDER funds that have allowed equipment to be purchased for research purposes, and also the Microscopy Service at the Polytechnic University of Valencia (UPV).Lario-Femenía, J.; Fombuena, V.; Vicente-Escuder, Á.; Amigó, V. (2018). Influence of Heat Treatment and UV Irradiation on the Wettability of Ti35Nb10Ta Nanotubes. Metals. 8(1):37-49. https://doi.org/10.3390/met8010037S374981Lario-Femenía, J., Amigó-Mata, A., Vicente-Escuder, Á., Segovia-López, F., & Amigó-Borrás, V. (2016). Desarrollo de las aleaciones de titanio y tratamientos superficiales para incrementar la vida útil de los implantes. Revista de Metalurgia, 52(4), 084. doi:10.3989/revmetalm.084Niinomi, M. (1998). Mechanical properties of biomedical titanium alloys. Materials Science and Engineering: A, 243(1-2), 231-236. doi:10.1016/s0921-5093(97)00806-xLong, M., & Rack, H. . (1998). Titanium alloys in total joint replacement—a materials science perspective. Biomaterials, 19(18), 1621-1639. doi:10.1016/s0142-9612(97)00146-4Niinomi, M. (2008). Mechanical biocompatibilities of titanium alloys for biomedical applications. Journal of the Mechanical Behavior of Biomedical Materials, 1(1), 30-42. doi:10.1016/j.jmbbm.2007.07.001Cochran, D. L., Schenk, R. K., Lussi, A., Higginbottom, F. L., & Buser, D. (1998). Bone response to unloaded and loaded titanium implants with a sandblasted and acid-etched surface: A histometric study in the canine mandible. Journal of Biomedical Materials Research, 40(1), 1-11. doi:10.1002/(sici)1097-4636(199804)40:13.0.co;2-qGil, F. J., Manzanares, N., Badet, A., Aparicio, C., & Ginebra, M.-P. (2013). Biomimetic treatment on dental implants for short-term bone regeneration. Clinical Oral Investigations, 18(1), 59-66. doi:10.1007/s00784-013-0953-zTan, A. W., Pingguan-Murphy, B., Ahmad, R., & Akbar, S. A. (2012). Review of titania nanotubes: Fabrication and cellular response. Ceramics International, 38(6), 4421-4435. doi:10.1016/j.ceramint.2012.03.002Minagar, S., Berndt, C. C., Wang, J., Ivanova, E., & Wen, C. (2012). A review of the application of anodization for the fabrication of nanotubes on metal implant surfaces. Acta Biomaterialia, 8(8), 2875-2888. doi:10.1016/j.actbio.2012.04.005ELIAS, C., OSHIDA, Y., LIMA, J., & MULLER, C. (2008). Relationship between surface properties (roughness, wettability and morphology) of titanium and dental implant removal torque. Journal of the Mechanical Behavior of Biomedical Materials, 1(3), 234-242. doi:10.1016/j.jmbbm.2007.12.002Brammer, K. S., Oh, S., Cobb, C. J., Bjursten, L. M., Heyde, H. van der, & Jin, S. (2009). Improved bone-forming functionality on diameter-controlled TiO2 nanotube surface. Acta Biomaterialia, 5(8), 3215-3223. doi:10.1016/j.actbio.2009.05.008Sista, S., Nouri, A., Li, Y., Wen, C., Hodgson, P. D., & Pande, G. (2013). Cell biological responses of osteoblasts on anodized nanotubular surface of a titanium-zirconium alloy. Journal of Biomedical Materials Research Part A, 101(12), 3416-3430. doi:10.1002/jbm.a.34638Ponsonnet, L., Reybier, K., Jaffrezic, N., Comte, V., Lagneau, C., Lissac, M., & Martelet, C. (2003). Relationship between surface properties (roughness, wettability) of titanium and titanium alloys and cell behaviour. Materials Science and Engineering: C, 23(4), 551-560. doi:10.1016/s0928-4931(03)00033-xOkazaki, Y., & Gotoh, E. (2005). Comparison of metal release from various metallic biomaterials in vitro. Biomaterials, 26(1), 11-21. doi:10.1016/j.biomaterials.2004.02.005Huang, H.-H., Wu, C.-P., Sun, Y.-S., & Lee, T.-H. (2013). Improvements in the corrosion resistance and biocompatibility of biomedical Ti–6Al–7Nb alloy using an electrochemical anodization treatment. Thin Solid Films, 528, 157-162. doi:10.1016/j.tsf.2012.08.063Eisenbarth, E., Velten, D., Müller, M., Thull, R., & Breme, J. (2004). Biocompatibility of β-stabilizing elements of titanium alloys. Biomaterials, 25(26), 5705-5713. doi:10.1016/j.biomaterials.2004.01.021Bauer, S., Pittrof, A., Tsuchiya, H., & Schmuki, P. (2011). Size-effects in TiO2 nanotubes: Diameter dependent anatase/rutile stabilization. Electrochemistry Communications, 13(6), 538-541. doi:10.1016/j.elecom.2011.03.003Das, K., Bose, S., & Bandyopadhyay, A. (2009). TiO2nanotubes on Ti: Influence of nanoscale morphology on bone cell-materials interaction. Journal of Biomedical Materials Research Part A, 90A(1), 225-237. doi:10.1002/jbm.a.32088Salou, L., Hoornaert, A., Louarn, G., & Layrolle, P. (2015). Enhanced osseointegration of titanium implants with nanostructured surfaces: An experimental study in rabbits. Acta Biomaterialia, 11, 494-502. doi:10.1016/j.actbio.2014.10.017Macak, J. M., Tsuchiya, H., Ghicov, A., Yasuda, K., Hahn, R., Bauer, S., & Schmuki, P. (2007). TiO2 nanotubes: Self-organized electrochemical formation, properties and applications. Current Opinion in Solid State and Materials Science, 11(1-2), 3-18. doi:10.1016/j.cossms.2007.08.004Puckett, S. D., Taylor, E., Raimondo, T., & Webster, T. J. (2010). The relationship between the nanostructure of titanium surfaces and bacterial attachment. Biomaterials, 31(4), 706-713. doi:10.1016/j.biomaterials.2009.09.081Çalışkan, N., Bayram, C., Erdal, E., Karahaliloğlu, Z., & Denkbaş, E. B. (2014). Titania nanotubes with adjustable dimensions for drug reservoir sites and enhanced cell adhesion. Materials Science and Engineering: C, 35, 100-105. doi:10.1016/j.msec.2013.10.033Le Guéhennec, L., Soueidan, A., Layrolle, P., & Amouriq, Y. (2007). Surface treatments of titanium dental implants for rapid osseointegration. Dental Materials, 23(7), 844-854. doi:10.1016/j.dental.2006.06.025Chen, J., Zhang, Z., Ouyang, J., Chen, X., Xu, Z., & Sun, X. (2014). Bioactivity and osteogenic cell response of TiO2 nanotubes coupled with nanoscale calcium phosphate via ultrasonification-assisted electrochemical deposition. Applied Surface Science, 305, 24-32. doi:10.1016/j.apsusc.2014.02.148WEN, H. B., LIU, Q., DE WIJN, J. R., DE GROOT, K., & CUI, F. Z. (1998). Journal of Materials Science Materials in Medicine, 9(3), 121-128. doi:10.1023/a:1008859417664Bharathidasan, T., Narayanan, T. N., Sathyanaryanan, S., & Sreejakumari, S. S. (2015). Above 170° water contact angle and oleophobicity of fluorinated graphene oxide based transparent polymeric films. Carbon, 84, 207-213. doi:10.1016/j.carbon.2014.12.004Yao, W., Li, Y., & Huang, X. (2014). Fluorinated poly(meth)acrylate: Synthesis and properties. Polymer, 55(24), 6197-6211. doi:10.1016/j.polymer.2014.09.036Zha, J., Ali, S. S., Peyroux, J., Batisse, N., Claves, D., Dubois, M., … Alekseiko, L. N. (2017). Superhydrophobicity of polymer films via fluorine atoms covalent attachment and surface nano-texturing. Journal of Fluorine Chemistry, 200, 123-132. doi:10.1016/j.jfluchem.2017.06.011Peters, A. M., Pirat, C., Sbragaglia, M., Borkent, B. M., Wessling, M., Lohse, D., & Lammertink, R. G. H. (2009). Cassie-Baxter to Wenzel state wetting transition: Scaling of the front velocity. The European Physical Journal E, 29(4), 391-397. doi:10.1140/epje/i2009-10489-3Giacomello, A., Meloni, S., Chinappi, M., & Casciola, C. M. (2012). Cassie–Baxter and Wenzel States on a Nanostructured Surface: Phase Diagram, Metastabilities, and Transition Mechanism by Atomistic Free Energy Calculations. Langmuir, 28(29), 10764-10772. doi:10.1021/la3018453Wang, R., Hashimoto, K., Fujishima, A., Chikuni, M., Kojima, E., Kitamura, A., … Watanabe, T. (1998). Photogeneration of Highly Amphiphilic TiO2 Surfaces. Advanced Materials, 10(2), 135-138. doi:10.1002/(sici)1521-4095(199801)10:23.0.co;2-mLiu, Z., Wang, Y., Peng, X., Li, Y., Liu, Z., Liu, C., … Huang, Y. (2012). Photoinduced superhydrophilicity of TiO2thin film with hierarchical Cu doping. Science and Technology of Advanced Materials, 13(2), 025001. doi:10.1088/1468-6996/13/2/025001Liu, Y., Lin, Z., Lin, W., Moon, K. S., & Wong, C. P. (2012). Reversible Superhydrophobic–Superhydrophilic Transition of ZnO Nanorod/Epoxy Composite Films. ACS Applied Materials & Interfaces, 4(8), 3959-3964. doi:10.1021/am300778dWang, R., Hashimoto, K., Fujishima, A., Chikuni, M., Kojima, E., Kitamura, A., … Watanabe, T. (1997). Light-induced amphiphilic surfaces. Nature, 388(6641), 431-432. doi:10.1038/41233Zhao, Y., Xiong, T., & Huang, W. (2010). Effect of heat treatment on bioactivity of anodic titania films. Applied Surface Science, 256(10), 3073-3076. doi:10.1016/j.apsusc.2009.11.075Mohan, L., Anandan, C., & Rajendran, N. (2015). Electrochemical behavior and effect of heat treatment on morphology, crystalline structure of self-organized TiO2 nanotube arrays on Ti–6Al–7Nb for biomedical applications. Materials Science and Engineering: C, 50, 394-401. doi:10.1016/j.msec.2015.02.013Bai, Y., Park, I. S., Park, H. H., Lee, M. H., Bae, T. S., Duncan, W., & Swain, M. (2011). The effect of annealing temperatures on surface properties, hydroxyapatite growth and cell behaviors of TiO2 nanotubes. Surface and Interface Analysis, 43(6), 998-1005. doi:10.1002/sia.368