IMPACT BEHAVIOR MODELING OF MOTORCYCLE FRONT WHEEL-TIRE ASSEMBLY

K. S. TAN,S. V. WONG,R. S. RADIN UMAR,N. K. GUPTA,A. M. S. HAMOUDA 한국자동차공학회 2009 International journal of automotive technology Vol.10 No.3

Experiments were conducted to investigate the influence of certain parameters that affect the impact response of the motorcycle front wheel-tire assembly under various impact conditions. Impact tests were conducted according to 2V 5–1 fractional factorial design using a pendulum impact test apparatus with impact speed, impact mass, tire inflation pressure level, striker geometry, and impact location as design factors. Significant factors influencing the response of the wheel-tire assembly were identified. Coefficients for each factor were also determined, and empirical models were then developed for each response. An analysis indicates that the developed models fit well within the experimental ranges of the respective factors. However, for several interaction effects, the models become unrealistic, whereby they give certain deformation values when approaching zero impact mass and/or zero impact velocity. This is not consistent with the mechanics of the physical world, as there should not be any significant deformation when delivered impact energy is small enough. Efforts have been made in developing better models to resolve the inconsistency and to include a wider range, especially considering the case of the lower limit of experimental factors, which are an impact mass of 51.18 kg and/or an impact velocity of 3 m s−1 (10.8 km/h) down to zero. The minimum amount of impact energy required to produce the onset of observable deformation on the wheel was incorporated in the development of new models. Finally, the present models have been developed not only to cover the lower regions but also to range up to the upper limits of the factors, which are an impact mass of 101.33 kg and an impact velocity of 6 m s−1 (21.6 km/h). Experiments were conducted to investigate the influence of certain parameters that affect the impact response of the motorcycle front wheel-tire assembly under various impact conditions. Impact tests were conducted according to 2V 5–1 fractional factorial design using a pendulum impact test apparatus with impact speed, impact mass, tire inflation pressure level, striker geometry, and impact location as design factors. Significant factors influencing the response of the wheel-tire assembly were identified. Coefficients for each factor were also determined, and empirical models were then developed for each response. An analysis indicates that the developed models fit well within the experimental ranges of the respective factors. However, for several interaction effects, the models become unrealistic, whereby they give certain deformation values when approaching zero impact mass and/or zero impact velocity. This is not consistent with the mechanics of the physical world, as there should not be any significant deformation when delivered impact energy is small enough. Efforts have been made in developing better models to resolve the inconsistency and to include a wider range, especially considering the case of the lower limit of experimental factors, which are an impact mass of 51.18 kg and/or an impact velocity of 3 m s−1 (10.8 km/h) down to zero. The minimum amount of impact energy required to produce the onset of observable deformation on the wheel was incorporated in the development of new models. Finally, the present models have been developed not only to cover the lower regions but also to range up to the upper limits of the factors, which are an impact mass of 101.33 kg and an impact velocity of 6 m s−1 (21.6 km/h).

Numerical simulations of collective magnetic properties and magnetoresistance in 2D ferromagnetic nanoparticle arrays

Tan, R P,Lee, J S,Cho, J U,Noh, S J,Kim, D K,Kim, Y K Institute of Physics [etc.] 2010 Journal of Physics. D, Applied Physics Vol.43 No.16

<P>Magnetic properties and magnetoresistance (MR) in 2D magnetic nanoparticle (NP) arrays are investigated by solving the Landau–Lifshitz–Gilbert equation at <I>T</I> = 0 K. The interparticle interactions induce a decrease in the coercive field and in the MR amplitude compared with the non-interacting case, while in some cases, the variation of the remanent magnetization is found to be non-monotonic when increasing the dipolar strength. For different values of the anisotropy, these variations of the coercive field, the remanent magnetization and the MR ratio are reproduced and exhibit a scaling on the dipolar/anisotropy ratio. These results suggest that the magnetic properties of the assemblies can be described by an individual or collective behaviour depending on the balance between the magnetic anisotropy and the dipolar interactions. In the case of strongly interacting NPs, the corresponding configurations of the magnetic moments at the remanent state reveal the formation of a ferromagnetic order at moderate dipolar strength (increase in the remanent magnetization) while small ferromagnetic domains/chains coupled antiferromagnetically are obtained in the case of strongly interacting NPs (decrease in the remanent magnetization). Such domains lead to a reduction in the MR amplitude and to a deviation from the <I>m</I><SUP>2</SUP>-law in the resistance-magnetic field [<I>R</I>(<I>H</I>)] characteristic of the non-interacting case.</P>

Age-related differences in the pathogenesis of chronic rhinosinusitis

Cho, S.H.,Hong, S.J.,Han, B.,Lee, S.H.,Suh, L.,Norton, J.,Lin, D.,Conley, D.B.,Chandra, R.,Kern, R.C.,Tan, B.K.,Kato, A.,Peters, A.,Grammer, L.C.,Schleimer, R.P. Mosby 2012 The Journal of allergy and clinical immunology Vol.129 No.3

Although chronic rhinosinusitis (CRS) significantly affects the quality of life of elderly people, the inflammatory mechanisms of chronic rhinosinusitis in the elderly have not been well studied. This study demonstrates that despite the higher severity of CRS observed in elderly patients, they had lower eosinophilic cationic protein compared to non-elderly CRS patients. In addition, S100A8/9 was significantly decreased in CRS with aging process, suggesting that epithelial barrier dysfunction may continue to play an important role in the pathogenesis of CRS while eosinophilic inflammation may subside with age.

세파클러 서방정의 제조

손영택,박미영,김상린,단현광 德成女子大學校 藥學硏究所 2003 藥學論文誌 Vol.14 No.1

Cefaclor is a semisynthetic cephalosporin for oral administration. It is absorbed 50∼75% after oral administration and having a biological half life of 0.6∼0.9hours. To maintain therapeutic range, the drug should be administrated 3∼4 times a day, which leads to the saw both kinetic of the absorption and resulting in ineffective therapy. Hence many authors attempted to develop sustained/extended release dosage forms for cefaclor in order to achieve effective administrated regimens. In this study we attempted to formulate cefaclor sustained release tablet by using HPMC(hydroxypropyl methylcellulose) and vinyl pyrrolidone vinyl acetate complex, which can provide convenient administration and are economic and the drug release from HPMC matrix is uniform irrespective of the pH. The cefaclor sustained release tablets were prepared by wet granulation techinique. The wet granules were dried at 50℃ for 5 hours in a tray drier. The dried granules were passed through sieve #20, lubricated with magnesium stearate by mixing in rapid mixer granulator and compressed using 7kgf/cm² punch to get tablets. In vitro release of cefaclor form formulated tablets was carried out in 0.1N HCl for 30 minute at 37±0.5℃ and 100rpm. The formulated cefaclor tablets were kept for a short term accelerated stability study in high temperature at 20℃, 50℃ for 4 weeks. And the formulation 16 18 carried out long term stability study for 24 months.

Mutant ubiquitin found in Alzheimer's disease causes neuritic beading of mitochondria in association with neuronal degeneration

Tan, Z,Sun, X,Hou, F-S,Oh, H-W,Hilgenberg, L G W,Hol, E M,van Leeuwen, F W,Smith, M A,O'Dowd, D K,Schreiber, S S Nature Publishing Group 2007 CELL DEATH AND DIFFERENTIATION Vol.14 No.10

A dinucleotide deletion in human ubiquitin (Ub) B messenger RNA leads to formation of polyubiquitin (UbB)+1, which has been implicated in neuronal cell death in Alzheimer's and other neurodegenerative diseases. Previous studies demonstrate that UbB+1 protein causes proteasome dysfunction. However, the molecular mechanism of UbB+1-mediated neuronal degeneration remains unknown. We now report that UbB+1 causes neuritic beading, impairment of mitochondrial movements, mitochondrial stress and neuronal degeneration in primary neurons. Transfection of UbB+1 induced a buildup of mitochondria in neurites and dysregulation of mitochondrial motor proteins, in particular, through detachment of P74, the dynein intermediate chain, from mitochondria and decreased mitochondria–microtubule interactions. Altered distribution of mitochondria was associated with activation of both the mitochondrial stress and p53 cell death pathways. These results support the hypothesis that neuritic clogging of mitochondria by UbB+1 triggers a cascade of events characterized by local activation of mitochondrial stress followed by global cell death. Furthermore, UbB+1 small interfering RNA efficiently blocked expression of UbB+1 protein, attenuated neuritic beading and preserved cellular morphology, suggesting a potential neuroprotective strategy for certain neurodegenerative disorders.Cell Death and Differentiation (2007) 14, 1721–1732; doi:10.1038/sj.cdd.4402180; published online 15 June 2007

Properties of hydroxyapatite synthesize by wet chemical method

S. Ramesh,S. Adzila,C.K.L. Jeffrey,C.Y. Tan,J. Purbolaksono,A.M. Noor,M.A. Hassan,I. Sopyan,W.D. Teng 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.4

The sintering behavior of a commercial HA and synthesized HA was investigated over the temperature range of 700 o C to 1400 o C in terms of phase stability, bulk density, Young’s modulus and Vickers hardness. In the present research, a wet chemical precipitation reaction was successfully employed to synthesize a submicron, highly crystalline, high purity and single phase stoichiometric HA powder that is highly sinteractive particularly at low temperature regimes below 1100 o C. It has been revealed that the sinterability of the synthesized HA was significantly greater than that of the commercial HA. The temperature for the onset of sintering and the temperature required to achieve densities above 98% of theoretical value were approximately 150 o C lower for the synthesized HA than the equivalent commercial HA. Nevertheless, decomposition of HA phase upon sintering was not observed in the present work for both powders.

Methyl Eugenol- Natural Sources, and its Fate and Role in Bactrocera dorsalis

K. H. Tan,A. K. W. Hee,C. C. H. Khoo,R. Nishida,S. L. Wee 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05

Effect of Poly(2-ethyl-2-oxazoline) on Multi-Walled Carbon Nanotubes Reinforced Poly(vinyl alcohol) Composites

Tan, S.H.,Suk, K.L.,Goak, J.C.,Hong, S.C.,Kim, J.-Y.,Lee, S.-W.,Kim, S.,Seo, Y.,Lee, N. RAPRA 2010 POLYMERS AND POLYMER COMPOSITES Vol.18 No.5

Edge perturbation on electronic properties of boron nitride nanoribbons

K.L. Wong,K.W. Lai,M.W. Chuan,Y. Wong,A. Hamzah,S. Rusli,N.E. Alias,S. Mohamed Sultan,C.S. Lim,M.L.P. Tan Techno-Press 2023 Advances in nano research Vol.15 No.5

Hexagonal boron nitride (h-BN), commonly referred to as Boron Nitride Nanoribbons (BNNRs), is an electrical insulator characterized by high thermal stability and a wide bandgap semiconductor property. This study delves into the electronic properties of two BNNR configurations: Armchair BNNRs (ABNNRs) and Zigzag BNNRs (ZBNNRs). Utilizing the nearest-neighbour tight-binding approach and numerical methods, the electronic properties of BNNRs were simulated. A simplifying assumption, the Hamiltonian matrix is used to compute the electronic properties by considering the self-interaction energy of a unit cell and the interaction energy between the unit cells. The edge perturbation is applied to the selected atoms of ABNNRs and ZBNNRs to simulate the electronic properties changes. This simulation work is done by generating a custom script using numerical computational methods in MATLAB software. When benchmarked against a reference study, our results aligned closely in terms of band structure and bandgap energy for ABNNRs. However, variations were observed in the peak values of the continuous curves for the local density of states. This discrepancy can be attributed to the use of numerical methods in our study, in contrast to the semi-analytical approach adopted in the reference work.

Newly Developed Microsatellite Markers of Mystus nemurus Tested for Cross-Species Amplification in Two Distantly Related Aquacultured Catfish Species

Chan, S.C.,Tan, S.G.,Siraj, S.S.,Yusoff, K. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.11

The work reported here is an attempt to explore the possibility of DNA microsatellite loci transfer (cross-species amplification) to other economically important aquacultured catfish species other than its source species. A total of 25 new microsatellite loci developed for riverine catfish, Mystus nemurus were successfully cross-amplified in two distantly related catfish species within the suborder Siluroidei. Five out of the 19 loci that successfully cross-amplified in Pangasius micronemus were polymorphic, while for Clarias batrachus, cross-amplification was successful using 17 polymorphic loci. The observed heterozygosities were high for all the three catfishes. The results indicated that microsatellite loci could be as polymorphic in non-source species as in the source species.