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      • KCI등재

        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).

      • SCISCIESCOPUS

        Photoluminescence, thermoluminescence and evaluation of some parameters of Dy<sup>3+</sup> activated Sr<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>F phosphor synthesized by sol-gel method

        Gupta, K.K.,Kadam, R.M.,Dhoble, N.S.,Lochab, S.P.,Singh, V.,Dhoble, S.J. Elsevier Sequoia 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.688 No.2

        In this study, we have synthesized Dy<SUP>3+</SUP> activated Sr<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F (S-FAP) phosphors by sol-gel synthesis method. The synthesized phosphors were characterized by X-ray diffraction pattern (XRD), scanning electron microscopic (SEM), photoluminescence (PL) and thermoluminescence (TL) for structural, morphological and luminescent properties. Dy<SUP>3+</SUP> activated Sr<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F phosphor shows its characteristic PL emission at 481 nm and 574 nm due to <SUP>4</SUP>F<SUB>9/2</SUB> → <SUP>6</SUP>H<SUB>15/2</SUB> and <SUP>4</SUP>F<SUB>9/2</SUB> → <SUP>6</SUP>H<SUB>13/2</SUB> transitions, respectively. TL characteristics of Dy<SUP>3+</SUP> doped Sr<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F phosphors were taken after irradiation by <SUP>60</SUP>Co gamma exposure. Two separate TL peaks at 126 <SUP>o</SUP>C and 279 <SUP>o</SUP>C were observed in case of Dy<SUP>3+</SUP> doped phosphor. Sr<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F:Dy<SUP>3+</SUP> phosphor was irradiated within a wide range of exposure of 50 Gy to 7 kGy doses. Linearity was found up to 2 kGy and thereafter TL response saturates. Fading study was also carried out over the duration of six weeks for Sr<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F phosphor. Trapping parameters were calculated using Chen's peak shape method, initial rise method and various heating rate method. Glow curve is deconvoluted using computerized glow curve deconvolution program. TL sensitivity of Sr<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F:Dy<SUP>3+</SUP> phosphor is found to be less by a factor of 2.08 than commercially used CaSO<SUB>4</SUB>:Dy phosphor. In order to identify the defect centers formed upon γ-ray irradiation in Sr<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F:Dy<SUP>3+</SUP> phosphor, EPR measurements were carried out on un-irradiated and irradiated phosphors.

      • Tourism in Maldives

        S,C,Bagri,S,K,Gupta,Reena Sharma 세계문화관광학회 2009 Conference Proceedings Vol.10 No.0

        The paper includes the growth of tourism since years in Maldives. The paper examines tourist development in Maldives. This will include the tourism indicators and impacts of tourism economically, socially and culturally. Although social/cultural impacts from coastal tourism development have been widely recognized in a great number of cases, it is relatively, difficult to develop technical criteria, for evaluating these impacts in quantitative terms. According to the Ministry of Tourism website, the emergence of tourism in 1972 transformed the economy of the Maldives, moving rapidly from the dependence on the fisheries sector to the tourism sector. Just in three and a half decades, the industry has become the main source of income and livelihood of the people of the Maldives. Tourism is also the country's biggest foreign currency earner and the single largest contributor to the GDP. Today, there are 89 resorts in the Maldives with a bed capacity of over 17,000, providing world class facilities for tourists whose annual arrival figure exceeds 600,000.

      • SCOPUSKCI등재

        Pharmacopuncture of Bauhinia variegata Nanoemulsion Formulation against Diabetic Peripheral Neuropathic Pain

        Gupta, Pushpraj S,Singh, Sunil K,Tripathi, Abhishek K KOREAN PHARMACOPUNCTURE INSTITUTE 2020 Journal of pharmacopuncture Vol.23 No.1

        Objectives: The objective of the study was to prepare Bauhinia variegata loaded nanoemulsion(formulation and determine the efficacy of herbal drug formulation against diabetic peripheral neuropathic pain through acupuncture technique. Methods: Nine different ba tches of nanoemulsion (NE1 NE9) of BVN was prepared by varying the S<sub>mix</sub> ratio and the concentration of oil. BVN was characterized to determine particle size, shape, zeta potential, polydispersity index, optical transmittance, drug release profile and stora ge stability. The optimized formulation was subjected to plantar test, behavioral tests of neuropathic pain and Von Frey filament stimulation test. Diabetes was induced by intraperitoneal injection of freshly prepared solution of Streptozotocin (60 mg/kg) to the experimental rats. Animals were made diabetic divided into four groups, Group I was untreated normal control group, Group II was diabetic control group, Group III was Bauhinia variegata extract ( treated group (100 mg/kg/day, p.o) and Group IV was BVN treated groups (100 mg/kg/day, p.o) acute and chronically. Results: The prepared B. variegata loaded nanoemulsion was nanosized (124 nm), spherical, uniform and stable over the period of 180 days with no change in physiochemical properties. The bl ood glucose and body weight of animals was normalizing after four weeks of treatment that was significant with BVN in comparison to diabetic control group. The chronic administration of BVN significantly (P<0.001) decreased hind paw withdrawal latency an d attenuated mechanical allodynia as compared with diabetic rats. Conclusion: Thus, BVN may be an effective drug formulation against diabetic peripheral neuropathic pain.

      • Electronic structure, magnetic and structural properties of Ni doped ZnO nanoparticles

        Kumar, S.,Vats, P.,Gautam, S.,Gupta, V.P.,Verma, K.D.,Chae, K.H.,Hashim, Mohd.,Choi, H.K. Pergamon Press 2014 Materials research bulletin Vol.59 No.-

        We report structural, magnetic and electronic structural properties of Ni doped ZnO nanoparticles prepared by auto-combustion method. The prepared nanoparticles were characterized by using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), near edge X-ray absorption fine structure (NEXAFS) spectroscopy, and dc magnetization measurements. The XRD and HR-TEM results indicate that Ni doped ZnO nanoparticles have single phase nature with wurtzite lattice and exclude the presence of secondary phase. NEXAFS measurements performed at Ni L<SUB>3,2</SUB>-edges indicates that Ni ions are in +2 valence state and exclude the presence of Ni metal clusters. O K-edge NEXAFS spectra indicate an increase in oxygen vacancies with Ni-doping, while Zn L<SUB>3,2</SUB>-edge show the absence of Zn-vacancies. The magnetization measurements performed at room temperature shows that pure and Ni doped ZnO exhibits ferromagnetic behavior.

      • KCI등재

        SOME POINT ESTIMATES FOR THE SHAPE PARAMETERS OF EXPONENTIATED-WEIBULL FAMILY

        UMESH SINGH,PRAMOD K. GUPTA,S. K. UPADHYAY 한국통계학회 2006 Journal of the Korean Statistical Society Vol.35 No.1

        Maximum product of spacings estimator is proposed in this paper asa competent alternative of maximum likelihood estimator for the parame-ters of exponentiated-Weibull distribution, which does work even when themaximum likelihood estimator does not exist. In addition, a Bayes type esti-mator known as generalized maximum likelihood estimator is also obtainedfor both of the shape parameters of the aforesaid distribution. Though, theclosed form solutions for these proposed estimators do not exist yet thesecan be obtained by simple appropriate numerical techniques. The relativeperformances of estimators are compared on the basis of their relative riskeciencies obtained under symmetric and asymmetric losses. An examplebased on simulated data is considered for illustration.AMS 2000 subject classications.Primary 62F10, 62F15, 93B40; Secondary 65C10,62N99.Keywords. Maximum product of spacings estimators, generalized maximum likelihoodestimators, maximum likelihood estimator, squared error loss function, LINEX loss func-tion, relative risk eciency, non-informative prior.1. IntroductionThe data obtained from lifetime experiments are referred to as failure timedata and such failure time data, results from dierent lifetime experiments con-ducted under sophisticated controlled and complex environments, exhibit dier-ent ypes of failure rates, which are generally categorized as, constant, monotoneReceived November 2004; accepted December 2005.yThis work was supported by Senior Research Fellowship (S.R.F), funded by Council ofScientic and Industrial Research (C.S.I.R.), India.

      • KCI등재

        Physical and Dielectric Properties of Aluminoborosilicate-Based Dielectrics Containing Different Divalent Oxides

        신동욱,Viswanathan S. Saji,Ravindra K. Gupta,조용수 한국세라믹학회 2007 한국세라믹학회지 Vol.44 No.11

        The variations of physical and dielectric properties of low temperature dielectrics based on typical aluminoborosilicate glasses modified with several divalent oxides were investigated. The divalent oxides studied here included CaO, MgO, BaO, SrO and ZnO. All samples containing either 35 wt% or 45 wt% alumina filler were prepared at the same processing condition and then fired at 850oC for 30 min. The resultant characteristics of fired samples depended on the choice of the divalent ion and the content of the alumina filler. Except for the ZnO modification, all other samples containing 35 wt% filler demonstrated promising densification as they exhibited reasonably high densities of 3.07-3.31 g/cm3 and high shrinkages of 14.0-16.4%. Particularly, the sample containing ZnO was distinguished with large variations compared to the base sample, which can be highlighted with earlier densification and crystallization at unexpectedly low temperatures. The negative effects of the ZnO modification on densification and dielectric properties were thought to be associated with earlier crystallization potentially by influencing effective densification via viscous flow. As an optimum composition, the sample containing only CaO showed the most promising characteristics such as k~8.05 and tanδ~0.0018 when 35 wt% alumina filler was used.

      • KCI등재

        Reduction of noxious Cr(VI) ion to Cr(III) ion in aqueous solutions using H2O2 and UV/H2O2 systems

        M.H. Dehghani,B. Heibati,A. Asadi,I. Tyagi,S. Agarwal,V.K. Gupta 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.33 No.-

        Conversion of the toxic Cr(VI) to the less toxic Cr(III) in aqueous solutions by chemical andphotochemical reduction was carried out using H2O2 and UV radiation. The whole mechanism was wellelucidated and investigated using potassium dichromate (K2Cr2O7) as a standard model compound. Theeffects of potential factors affecting the reduction efficiency were well studied and optimized, theoptimized parameters such as concentration of H2O2 (from 0.5 to 1.5 M), pH (from 5 to 9), irradiationtime (0 to 140 min) and reaction time (0 to 120 min). Initial concentration of Cr(VI) in the solution wasvaried from 0.1 to 15 mg/L plays a significant role in the mechanism involves for the reduction of noxiousCr(VI) to less toxic Cr(III).

      • KCI등재

        Comparative analysis of VMT genes/proteins in selected plant species with emphasis on bread wheat (Triticum aestivum L.)

        Sharma Hemant,Shayaba,Kumar Rahul,Kumar Jitendra,Bhadana Deepa,Batra Ritu,Singh Rakhi,Kumar Sachin,Roy Joy K,Balyan Harindra S.,Gupta Pushpendra K. 한국유전학회 2023 Genes & Genomics Vol.45 No.11

        Background In recent years, the study of molecular basis of uptake, transport and utilization of grain Fe/Zn (GFe/GZn) in wheat has been an active area of research. As a result, it has been shown that a number of transporters are involved in uptake and transport of Fe. In a recent study, knockout of a transporter gene OsVMT (VACUOLAR MUGINEIC ACID TRANSPORTER) in rice was shown to be involved in Fe homoeostasis. Objective In this study, we analysed VMT genes among six monocots and three dicots with major emphasis on wheat VMT genes (TaVMTs), taking OsVMT gene as a reference. Methods and results Using OsVMT gene as a reference, VMT genes were identified and sequence similarities were examined among six monocots and three dicots. Each VMT protein carried one functional domain and 7 to 10 distinct motifs (including 9 novel motifs). The qRT-PCR analysis showed differential expression by all the six TaVMT genes in pairs of contrasting wheat genotypes with high (FAR4 and WB02) and low (K8027 and HD3226) GFe/GZn at two different grain filling stages (14 DAA and 28 DAA). TaVMT1 genes showed up-regulation in high GFe/Zn genotypes relative to low GFe/Zn genotypes, whereas the TaVMT2 genes showed down-regulation or nonsignificant up-regulation in a few cases. Conclusions At 14 DAA, each of the six TaVMT genes exhibited higher expression in wheat genotypes with high GFe and GZn relative to those with low GFe and GZn, suggesting major role of VMT genes in improvement of grain Fe/Zn homoeostasis, thus making TaVMT genes useful for improvement in Fe/Zn in wheat grains.

      • Final report for the APMP.T-K4: Comparison of realizations of aluminium freezing-point temperatures

        Gam, K S,Joung, W,Yamazawa, K,Cheung, C P,Kho, H Y,Wang, L,Tsai, S F,Norranim, U,Hafidzah, O,Gupta, J K Springer-Verlag 2013 Metrologia Vol.50 No.-

        <P>The comparison APMP.T-K4 is the regional extension of the CCT-K4: an intercomparison of the realizations of the freezing-points of Al (660.323 °C) and Ag (961.78 °C). The comparison was organized in two loops and four sub-loops with high temperature standard platinum resistance thermometers (HTSPRTs) as transfer thermometers in the freezing-point comparisons. The comparison involved eight APMP NMIs (KRISS, NMIJ, SCL, NMC, CMS, NIMT, SIRIM, NPL), and KRISS and NMIJ acted as linking laboratories to the CCT-K4.</P><P>The transfer HTSPRTs showed a strong drift during the transportation between the NMIs. In the case of the Ag freezing-point comparison, the comparison results were scattered much more than expected. In the APMP meeting held in 2009, the participants agreed that the Ag comparison results would be omitted in the report. It revealed that the measurement results at the Al freezing-point of participants were in agreement with the key comparison reference value of the CCT-K4 within 4 mK except for one laboratory. Details of the comparison results, the uncertainty evaluation and the drift of the HTSPRTs are described in this report.</P><P>Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.</P><P>The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

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