Template-Free Growth of Novel Hydroxyapatite Nanorings: Formation Mechanism and Their Enhanced Functional Properties

Nathanael, A. Joseph,Hong, Sun Ig,Mangalaraj, D.,Ponpandian, N.,Chen, Pao Chi American Chemical Society 2012 Crystal Growth & Design Vol.12 No.7

<P>Template-free, single crystalline novel hydroxyapatite (HAp) nanorings with an inner diameter of 70 nm were grown by a combined high gravity and hydrothermal approach. Nanodisks were suggested to be formed by oriented aggregation and Ostwald ripening of mostly calcium pyrophosphate nanospheres prepared initially by the high gravity method with a stepwise increase of flow rate of phosphate solution. The prolonged hydrothermal treatment of nanodisks appeared to induce the nanoring formation via acid penetration along the dislocations in HAp nanodisks. The presence of edge dislocations in the central region of nanodisks was confirmed by high resolution transmission electron microscopy. The mechanical evaluation of high molecular weight polyethylene (HMWPE) composite with various shaped HAp nanocrystals and in vitro cellular analysis of HAp nanocrystals revealed that mechanical and bioactive performances improved with an increase of the specific surface area of HAp nanocrystals. The enhanced mechanical performance of HMWPE/HAp nanoring composite and the excellent cell viability for HAp nanorings are attributed to the superior interface bonding and cell activity, respectively, both of which are enhanced by the high specific surface area.</P><P>This work describes the template free growth mechanism and the enhanced properties of novel hydroxyapatite nanorings. Formation of nanodisk was explained by initial oriented aggregation and Ostwald ripening. Nanoring formation was suggested to be induced by acid penetration along the dislocations. Mechanical and in vitro analysis proved the enhanced functional properties of this novel structure.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cgdefu/2012/cgdefu.2012.12.issue-7/cg3003959/production/images/medium/cg-2012-003959_0001.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cg3003959'>ACS Electronic Supporting Info</A></P>

PVP Assisted Synthesis of Hydroxyapatite Nanorods with Tunable Aspect Ratio and Bioactivity

Nathanael, A. Joseph,Seo, Young Ho,Oh, Tae Hwan Hindawi Limited 2015 Journal of nanomaterials Vol.2015 No.-

<P>Highly crystalline and reasonably uniform hydroxyapatite (HA) nanorods were prepared by polyvinylpyrrolidone (PVP) assisted hydrothermal synthesis which produces high aspect ratio (length/width) nanorods. The aspect ratio of the nanorods was higher in the presence of PVP and increased with increasing concentrations of PVP. X-ray diffraction (XRD) analysis showed that the HA nanorods were of the hexagonal apatite phase. High resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) patterns confirmed that the nanorods grew in the<I>c</I>-axis direction (preferred orientation). The calculated lattice spacing was ~0.35 nm which is the<I>c</I>-axis value of hexagonal HA. Morphological variations of pristine and PVP added HA were evaluated by field emission scanning electron microscopy (FESEM) and TEM, which revealed that the presence of PVP greatly increased the aspect ratio of the HA nanorods. The formation mechanism of the PVP assisted HA was studied and a possible reaction model was given. Cell viability analysis by<I>in vitro</I>studies showed encouraging results for the high aspect ratio nanorods and indicated a possibility for tuning the activity based on controlling the aspect ratio.</P>

Novel Zirconium Nitride and Hydroxyapatite Nanocomposite Coating: Detailed Analysis and Functional Properties

Nathanael, A. Joseph,Yuvakkumar, R.,Hong, Sun Ig,Oh, Tae Hwan American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.12

<P>A new type of high-quality zirconium nitride (ZrN) and hydroxyapatite (HA) bionanocomposite was prepared by radio-frequency (RF) magnetron sputtering for biomedical applications. Detailed analysis of this composite coating revealed that a higher substrate temperature (ST) (>300 °C) increased its crystallinity, uniformity, and functional properties. This nanocomposite showed some encouraging functional properties. Mechanical analyses of the nanocomposite showed improved hardness, modulus, and wear resistance, which were found to be due to the increasing volume fraction of ZrN at higher ST. Biomineralization and in vitro cell analysis revealed increased weight gain and enhanced cell activity with increased substrate temperature. Overall, the results of the present study indicate that this nanocomposite coating could become a promising alternative for biomedical applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-12/am5023557/production/images/medium/am-2014-023557_0014.gif'></P>

Adaptive selection of dynamic VM consolidation algorithm using neural network for cloud resource management

Witanto, Joseph Nathanael,Lim, Hyotaek,Atiquzzaman, Mohammed Elsevier 2018 Future generation computer systems Vol.87 No.-

<P><B>Abstract</B></P> <P>Cloud resource management becomes more important with the increasing usage of cloud resources. With various cloud options available, cloud provider may have different priority in managing the resource through resource scheduling and provisioning. Dynamic VM (Virtual Machine) consolidation algorithm is one of the techniques which can be used to reduce energy consumption through VM migration. Higher VM migration may lead to lower energy consumption and higher SLA violation. Although previous research has successfully decreased energy consumption and SLA violation, cloud providers may need to manage trade-offs between energy and SLA violation through availability of priority in the system. This paper proposes neural network-based adaptive selection of VM consolidation algorithms which adaptively chooses appropriate algorithm according to cloud provider’s goal priority and environment parameters. Dataset generation and performance evaluation using simulations on real-world PlanetLab VMs workload trace showed that adaptive selector produced better average performance score than independent methods on various evaluation priority.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Studies on multiple dynamic VM consolidation algorithms on cloud environment. </LI> <LI> Discusses about trade-off between energy and SLA violation due to VM migration. </LI> <LI> Proposes adaptive system which chooses best algorithm based on provider’s priority. </LI> <LI> Evaluates performance of proposed system and individual VM migration algorithms. </LI> </UL> </P>

Smart government framework with geo-crowdsourcing and social media analysis

Witanto, Joseph Nathanael,Lim, Hyotaek,Atiquzzaman, Mohammed North-Holland 2018 Future generations computer systems Vol.89 No.-

<P><B>Abstract</B></P> <P>Smart government utilizes data to improve services provided to the citizen. Smart city may benefit from citizen engagement through crowdsourcing and social media. This paper proposes a city event’s prediction with map-based visualization utilizing crowdsourced geodata collected from citizen’s report. Data is aggregated according to geo-position and used to predict next day’s event. Mindmap-based visualization utilizing social media processed with topic modeling and topic similarity calculation is also proposed in this work. Proof-of-concept application and proposed system’s processing time is evaluated to prove the feasibility of the system. Proposed system utilizes geo-crowdsourcing for event prediction visualization for government instead of direct services to citizen. Proposed social media visualization use topic modeling specifically created for short text which is appropriate for social media data.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Proposes map-based reporting for government-related activities based on geo-crowdsourced data. </LI> <LI> Proposes mindmap-based reporting for social media analysis. </LI> <LI> Evaluates smart city frameworks, geo-crowdsourcing and social media analysis applications. </LI> </UL> </P>

Preparation of TiO2-coated ZnO Nanoparticles and Their Effect on the UV Absorption of a Poly(vinyl alcohol) Composite Film

김규식,Joseph A. Nathanael,김유진,오태환 한국섬유공학회 2018 Fibers and polymers Vol.19 No.8

Titanium oxide (TiO2) and zinc oxide (ZnO) composite structured nanoparticles were prepared by combining a sol-gel process and a solvothermal method. Titanium (IV) isoproxide (TTIP), used as a TiO2 precursor, was dissolved in a colloidal ZnO nanoparticle solution synthesized by the sol-gel method, and TiO2 was synthesized via solvothermal synthesis onto the ZnO nanoparticles. The effects of reaction conditions such as pH, reaction temperature, and reaction time on the morphology of the composite nanoparticles and the ultraviolet (UV) absorbance of their polymer composite films were investigated. The UV absorption of the poly(vinyl alcohol) (PVA) composite film with TiO2-coated ZnO nanoparticles was higher than that of the TiO2, ZnO, and ZnO-coated TiO2 composite films. The reaction pH was found to have the strongest influence on the UV absorbance of the PVA/(TiO2/ZnO) composite film. A pH of 7.0, reaction temperature of 250 oC, and reaction time of 24 h were the optimum conditions for UV absorption.

Rice husk ash nanosilica to inhibit human breast cancer cell line (3T3)

Yuvakkumar, R.,Nathanael, A. Joseph,Rajendran, V.,Hong, S. I. Springer-Verlag 2014 Journal of sol-gel science and technology Vol.72 No.1

Preparation of PEO/PEDOT-PSS conductive nano sheets via Electrospinning

황준성,서영호,차진욱,임영민,Joseph Nathanael,이성준,김민재,임호용,김세현,오태환 한국고분자학회 2014 한국고분자학회 학술대회 연구논문 초록집 Vol.2014 No.4

Macroparticles Reduction Using Filter Free Cathodic Vacuum Arc Deposition Method in ZnO Thin Films.

Yuvakkumar, R,Peranantham, P,Nathanael, A Joseph,Nataraj, D,Mangalaraj, D,Hong, Sun Ig American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.3

<P>We report a new method to reduce macroparticles in ZnO thin films using filter free cathodic vacuum arc deposition without using any cooling arrangements operated at low arc current. The detailed mechanism has been proposed to reduce macroparticles during thin film deposition. The successful reduction of macroparticles was confirmed employing FESEM-EDX studies. FESEM images of ZnO thin films deposited with cathode spot to substrate distance from 10 to 20 cm revealed that the population of the macroparticles were reduced with the increase of cathode spot to substrate distances at low arc current. The prepared ZnO films were characterised and showed good structural and optical properties.</P>

Rambutan peels promoted biomimetic synthesis of bioinspired zinc oxide nanochains for biomedical applications

Yuvakkumar, R.,Suresh, J.,Saravanakumar, B.,Joseph Nathanael, A.,Hong, S.I.,Rajendran, V. Pergamon 2015 Spectrochimica acta. Part A, Molecular and biomole Vol.137 No.-

A naturally occurring rambutan peel waste was employed to synthesis bioinspired zinc oxide nanochains. Rambutan peels has the ability of ligating zinc ions as a natural ligation agent resulting in zinc oxide nanochains formation due to its extended polyphenolic system over incubation period. Successful formation of zinc oxide nanochains was confirmed employing transmission electron microscopy studies. About 60% and ~40% cell viability was lost and 50% and 10% morphological change was observed in 7 and 4days incubated ZnO treated cells compared with control. Moreover, 50% and 55% of cell death was observed at 24 and 48h incubation with 7days treated ZnO cells and hence alters and disturbs the growth of cancer cells and could be used for liver cancer cell treatment.