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).

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.

OH reactivity at a rural site (Wangdu) in the North China Plain: contributions from OH reactants and experimental OH budget

Fuchs, Hendrik,Tan, Zhaofeng,Lu, Keding,Bohn, Birger,Broch, Sebastian,Brown, Steven S.,Dong, Huabin,Gomm, Sebastian,Hä,seler, Rolf,He, Lingyan,Hofzumahaus, Andreas,Holland, Frank,Li, Xin,Liu, Ying Copernicus GmbH 2017 Atmospheric chemistry and physics Vol.17 No.1

<P>Abstract. In 2014, a large, comprehensive field campaign was conducted in the densely populated North China Plain. The measurement site was located in a botanic garden close to the small town Wangdu, without major industry but influenced by regional transportation of air pollution. The loss rate coefficient of atmospheric hydroxyl radicals (OH) was quantified by direct measurements of the OH reactivity. Values ranged between 10 and 20 s−1 for most of the daytime. Highest values were reached in the late night with maximum values of around 40 s−1. OH reactants mainly originated from anthropogenic activities as indicated (1) by a good correlation between measured OH reactivity and carbon monoxide (linear correlation coefficient R2 = 0.33) and (2) by a high contribution of nitrogen oxide species to the OH reactivity (up to 30 % in the morning). Total OH reactivity was measured by a laser flash photolysis-laser-induced fluorescence instrument (LP-LIF). Measured values can be explained well by measured trace gas concentrations including organic compounds, oxygenated organic compounds, CO and nitrogen oxides. Significant, unexplained OH reactivity was only observed during nights, when biomass burning of agricultural waste occurred on surrounding fields. OH reactivity measurements also allow investigating the chemical OH budget. During this campaign, the OH destruction rate calculated from measured OH reactivity and measured OH concentration was balanced by the sum of OH production from ozone and nitrous acid photolysis and OH regeneration from hydroperoxy radicals within the uncertainty of measurements. However, a tendency for higher OH destruction compared to OH production at lower concentrations of nitric oxide is also observed, consistent with previous findings in field campaigns in China. </P>

Utility of FDG-PET/CT for the Detection and Characterization of Sternal Wound Infection Following Sternotomy

Hadi Hariri,Stéphanie Tan,Patrick Martineau,Yoan Lamarche,Michel Carrier,Vincent Finnerty,Sébastien Authier,Francois Harel,Matthieu Pelletier-Galarneau 대한핵의학회 2019 핵의학 분자영상 Vol.53 No.4

Purpose FDG-PET/CT has the potential to play an important role in the diagnosis of sternal wound infections (SWI). The purpose of this study was to analyze the diagnostic accuracy of FDG-PET/CT for SWI in patients following sternotomy. Methods We performed a single-center, retrospective analysis of patients who had undergone median sternotomy and FDG-PET/ CT imaging. The gold standard consisted of positive bacterial culture and/or the presence of purulent material at surgery. Qualitative patterns of sternal FDG uptake, SUVmax, and associated CT findings were determined, and an imaging scoring system was developed. The diagnostic performances were studied in both the recent (≤ 6 months between sternotomy and imaging) and remote surgery phase (> 6 months). Results A total of 40 subjects were identified with 11 confirmed SWI cases. Consensus interpretation was associated with a sensitivity of 91%and specificity of 97%. Combination of uptake patterns yielded an AUC of 0.96 while use of SUVmax yielded an AUC of 0.82. Conclusions Results suggest that FDG-PET/CT may be useful for the diagnosis of SWI with optimal diagnostic accuracy achieved by identifying specific patterns of uptake. SUVmax can be helpful in assessing subjects with remote surgery, but its use is limited in the context of recent surgery. Further studies are required to confirm these results.

Investigating the electrochemical windows of ionic liquids

Maan Hayyan,Farouq S. Mjalli,Mohd Ali Hashim,Inas M. AlNashef,Tan Xue Mei 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.1

The structure effect on the electrochemical windows (EWs) was studied using cyclic voltammetry (CV) in 16 ionic liquids (ILs), consisting of various cations such as piperidinium, pyridinium, pyrrolidinium,phosphonium, morpholinium, ammonium, sulfonium and imidazolium, and anions including bis(trifluoromethylsulfonyl)imide, tris(pentafluoroethyl)trifluorophosphate, dicyanamide, trifluoroacetate and trifluoromethanesulfonate. It was found that all studied ILs have good EWs to be utilized as electrolytes in different electrochemical applications pertaining to industry. Furthermore, it was found that the structure of ILs affected the EW and both the cation and anion have important effect on the reductive and oxidative limits, respectively. The reductive limits of the studied ILs were found to follow the sequence of [P14,666]+ > [N112,1O2]+ > [HMPyrr]+ > [BMPyrr]+ > [EMIm]+ > [MOEMMor]+≈[MOPMPip]+ > [S222]+ > [BMPy]+≈[HPy]+≈ [HPPy]+. The oxidative limits were found to follow the sequence of [TFSI]ˉ > [TPTP]ˉ > [TfO]ˉ > [DCA]ˉ > [TFA]ˉ. 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Differential Effects of Pentoxifylline on Learning and Memory Impairment Induced by Hypoxic-ischemic Brain Injury in Rats

Hülya Halis,Soner Bitiktaş,Osman Baştuğ,Burak Tan,Şehrazat Kavraal,Tamer Güneş,Cem Süer 대한정신약물학회 2019 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.17 No.3

Objective: Hypoxic-ischemic (HI) brain injury in the human perinatal period often leads to significant long-term neurobehavioral dysfunction in the cognitive and sensory-motor domains. Using a neonatal HI injury model (unilateral carotid ligation followed by hypoxia) in postnatal day seven rats, the present study investigated the long-term effects of HI and potential behavioral protective effect of pentoxifylline. Methods: Seven-day-old rats underwent right carotid ligation, followed by hypoxia (FiO2 = 0.08). Rats received pentoxifylline immediately after and again 2 hours after hypoxia (two doses, 60‒100 mg/kg/dose), or serum physiologic. Another set of seven-day-old rats was included to sham group exposed to surgical stress but not ligated. These rats were tested for spatial learning and memory on the simple place task in the Morris water maze from postnatal days 77 to 85. Results: HI rats displayed significant tissue loss in the right hippocampus, as well as severe spatial memory deficits. Low-dose treatment with pentoxifylline resulted in significant protection against both HI-induced hippocampus tissue losses and spatial memory impairments. Beneficial effects are, however, negated if pentoxifylline is administered at high dose. Conclusion: These findings indicate that unilateral HI brain injury in a neonatal rodent model is associated with cognitive deficits, and that low dose pentoxifylline treatment is protective against spatial memory impairment

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.

Asymmetric Superimposed Optical Vortex Beam Emission at Exceptional Point

Tan, James Y. S.,Kyoungsik Yu Institute of Electrical and Electronics Engineers 2017 IEEE photonics technology letters Vol.29 No.10

<P>Mirror-symmetric microring resonators perturbed by periodically spaced scatterers induce symmetric optical vortex superimposition states. In this letter, we theoretically and numerically show that a broken mirror symmetric resonator can induce asymmetric optical orbital angular momentum (OAM) superimposition states. The asymmetric OAM behaviour is due to the chiral and non-orthogonal resonator modes at exceptional point. Potential applications of the OAM beam emission behavior could include information processing and particle micromanipulation with functionality-switching capabilities.</P>

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.

The New Mechanism to Detect and Prevent BlackHole Attacks on AODV-Based MANET

Tan, S.V.,Choi, M.Y.,Kim, K.C. TRANS TECH PUBLICATION LTD 2013 Advanced materials research Vol.684 No.-