ROLLOVER SIMULATION OF SPORTS UTILITY VEHICLES

M. RAM PRABHU(M. RAM PRABHU),N.S. ANDRES(N.S. ANDRES),엄용균(Y.G. Eom),장봉춘(B.C. JANG) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.5_2

The simulations on dynamic stability of Sports Utility Vehicles using Carsim/Vehsim software are presented on this paper with the aim of studying the rollover process occurring in such vehicles. Carsim/Vehsim is an integrated simulation package that has been developed for chassis dynamics controls and integration. The simulation procedure makes use of dynamic testing maneuvers (Fishhook tests, J-Turn test and Double Lane Change test) recommended by NHTSA to evaluate the antirollover propensities of SUVs on road. The simulation results emphasize the need for better understanding of SUV rollover performance and characteristics that are very essential in enhancing vehicle design. Furthermore, the simulation dramatically shows less development time and cost reduction compared to field testing. This paper, in general, investigates the dynamic rollover characteristics of 4 SUVs in 2 different road conditions.

A Comparative Study of Operating Angle Optimization of Switched Reluctance Motor with Robust Speed Controller using PSO and GA

Prabhu, V. Vasan,Rajini, V.,Balaji, M.,Prabhu, V. The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.2

This paper's focus is in reducing the torque ripple and increasing the average torque by optimizing switching angles of 8/6 switched reluctance motor while implementing a robust speed controller in the outer loop. The mathematical model of the machine is developed and it is simulated using MATLAB/Simulink. An objective function and constraints are formulated and Optimum turn-on and turn-off angles are determined using Particle swarm optimization and Genetic Algorithm techniques. The novelty of this paper lies in implementing sliding mode speed controller with optimized angles. The results from both the optimization techniques are then compared with initial angles with one of them clearly being the better option. Speed response is compared with PID controller.

A Comparative Study of Operating Angle Optimization of Switched Reluctance Motor with Robust Speed Controller using PSO and GA

V. Vasan Prabhu,V. Rajini,M. Balaji,V. Prabhu 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.2

This paper’s focus is in reducing the torque ripple and increasing the average torque by optimizing switching angles of 8/6 switched reluctance motor while implementing a robust speed controller in the outer loop. The mathematical model of the machine is developed and it is simulated using MATLAB/Simulink. An objective function and constraints are formulated and Optimum turn-on and turn-off angles are determined using Particle swarm optimization and Genetic Algorithm techniques. The novelty of this paper lies in implementing sliding mode speed controller with optimized angles. The results from both the optimization techniques are then compared with initial angles with one of them clearly being the better option. Speed response is compared with PID controller.

Exposure to Atmospheric Particulates and Associated Respirable Deposition Dose to Street Vendors at the Residential and Commercial Sites in Dehradun City

Prabhu, Vignesh,Gupta, Sunil K.,Madhwal, Sandeep,Shridhar, Vijay Occupational Safety and Health Research Institute 2019 Safety and health at work Vol.10 No.2

Background: Street vendors spend relatively more time near roadways and are vulnerable to air pollution related health disorders. However, there is limited information on the quality of the air they breathe. The objectives of this present study were to calculate the mass concentration of atmospheric particulate matter (PM) in eight size fractions ($PM_{0.4-0.7}$, $PM_{0.7-1.1}$, $PM_{1.1-2.1}$, $PM_{2.1-3.3}$, $PM_{3.3-4.7}$, $PM_{4.7-5.8}$, $PM_{5.8-9.0}$, and $PM_{9.0--0{\mu}m}$) at commercial (CML) and residential site (RSL) in Dehradun city from November 2015 to May 2016. To estimate the corresponding respiratory deposition dose (RDDs) in alveolar (AL), tracheobronchial (TB), and head airway (HD) region on street vendors working at CML and RSL. To find the association of atmospheric PM with RDDs and the incidence of respiratory related disorders among street vendors. Methods: Andersen cascade impactor was employed for calculating the PM mass concentration. Questionnaire based health survey among street vendors were carried out through personal interview. Results: A significant difference (p < 0.05; t-test) between the mean $PM_{0.4-10{\mu}m}$ mass concentration at CML and RSL was observed with ($mean{\pm}SD$) $84.05{\pm}14.5$ and $77.23{\pm}11.7{\mu}g\;m^{-3}$, respectively. RDDs in AL, TB and HD region at CML was observed to be 9.9, 7.8, and 7.3% higher than at RSL, respectively. Health survey revealed 1.62, 0.96, 0.04, and 0.57 times higher incidence of cold, cough, breathlessness, and chest pain, respectively with street vendors at CML compared to RSL. Conclusion: The site characteristics plays a major role in the respiratory health status of street vendors at Dehradun.

Metabolite signature associated with stress susceptibility in socially defeated mice

Prabhu, Vishwanath Vasudev,Nguyen, Thong Ba,Cui, Yin,Oh, Young-Eun,Piao, Yan-Hong,Baek, Hyeon-Man,Kim, Joo-Yeon,Shin, Kwang-Hee,Kim, Ji-hyun,Lee, Keon-Hak,Chung, Young-Chul Elsevier 2019 Brain Research Vol.1708 No.-

<P><B>Abstract</B></P> <P><B>Objective</B></P> <P>Social defeat represents a naturalistic form of conditioned fear and is often used as an animal model of depression. The present study aimed to identify the neurochemicals in select brain regions of mice exposed to social defeat stress.</P> <P><B>Methods</B></P> <P>Adult <I>C57BL/6N</I> mice were subjected social defeat stress for 10 days. Using high-resolution magic angle spinning <SUP>1</SUP>H nuclear magnetic resonance (HR-MAS <SUP>1</SUP>H NMR), untargeted metabolomes were measured in the amygdala (AMY), dorsal hippocampus (dHIP), dorsal striatum (dST), and prefrontal cortex (PFC).</P> <P><B>Results</B></P> <P>We observed perturbations of glutamine in the AMY; glutamate in the dHIP; glycine and myo-inositol in the dST; and aspartate, choline, and phosphoethanolamine in the PFC of susceptible and/or unsusceptible groups compared to the control group. The susceptible and unsusceptible groups significantly differed with regard to three metabolites: glutamine, glycine, and choline.</P> <P><B>Conclusion</B></P> <P>These findings suggest that social defeat stress induces disturbances in the metabolism of amino acids, lipids, and neurotransmitters in several brain areas. The resulting susceptibility-related metabolites may provide new insights into the pathophysiology underlying stress-related mental illness.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Defeated mice were classified as unsusceptible and susceptible groups. </LI> <LI> HR-MAS <SUP>1</SUP>H NMR revealed disturbances in the metabolites of defeated mice brain. </LI> <LI> Results may elucidate pathophysiological mechanisms related to stress susceptibility. </LI> </UL> </P>

Targeting Tumor Metastasis by Regulating Nm23 Gene Expression

Prabhu, V. Vinod,Siddikuzzaman, Siddikuzzaman,Grace, V.M. Berlin,Guruvayoorappan, C. Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

The Nm23 gene is a metastatic suppressor identified in a melanoma cell line and expressed in different tumors where their levels of expression are associated with reduced or increased metastatic potential. Nm23 is one of the over 20 metastasis suppressor genes (MSGs) confirmed in vivo. It is highly conserved from yeast to human, implying a critical developmental function. Tumors with alteration of the p53 gene and reduced expression of the Nm23 gene are more prone to metastasis. Nm23-H1 has 3'-5' exonuclease activity. This review focuses on the role of Nm23 in cancer progression and also a potential novel target for cancer therapy.

Probing the Molecular Determinant for the Catalytic Efficiency of l-Arabinose Isomerase from Bacillus licheniformis

Prabhu, Ponnandy,Jeya, Marimuthu,Lee, Jung-Kul American Society for Microbiology 2010 Applied and environmental microbiology Vol.76 No.5

<B>ABSTRACT</B><P><I>Bacillus licheniformis</I>l-arabinose isomerase (l-AI) is distinguished from other l-AIs by its high degree of substrate specificity for l-arabinose and its high turnover rate. A systematic strategy that included a sequence alignment-based first screening of residues and a homology model-based second screening, followed by site-directed mutagenesis to alter individual screened residues, was used to study the molecular determinants for the catalytic efficiency of <I>B. licheniformis</I>l-AI. One conserved amino acid, Y333, in the substrate binding pocket of the wild-type <I>B. licheniformis</I>l-AI was identified as an important residue affecting the catalytic efficiency of <I>B. licheniformis</I>l-AI. Further insights into the function of residue Y333 were obtained by replacing it with other aromatic, nonpolar hydrophobic amino acids or polar amino acids. Replacing Y333 with the aromatic amino acid Phe did not alter catalytic efficiency toward l-arabinose. In contrast, the activities of mutants containing a hydrophobic amino acid (Ala, Val, or Leu) at position 333 decreased as the size of the hydrophobic side chain of the amino acid decreased. However, mutants containing hydrophilic and charged amino acids, such as Asp, Glu, and Lys, showed almost no activity with l-arabinose. These data and a molecular dynamics simulation suggest that Y333 is involved in the catalytic efficiency of <I>B. licheniformis</I>l-AI.</P>

Synthesis and characterization of graphene oxide-doped nano-hydroxyapatite and its adsorption performance of toxic diazo dyes from aqueous solution

Prabhu, Subbaiah Muthu,Khan, Abuzar,Hasmath Farzana, M.,Hwang, Gil Chan,Lee, Woojin,Lee, Giehyeon Elsevier 2018 Journal of molecular liquids Vol.269 No.-

<P>In this study, graphene oxide-doped nano-hydroxyapatite (nHAp@GO) composite was synthesized via a simple in-situ one-pot method and was used as an adsorbent for the removal of toxic diazo dyes, Congo Red (CR) and Trypan Blue (TB), in water. A remarkable adsorption capacity for CR (48.5 mg/g) and TB (41.0 mg/g) were shown on the surface of nHAp@GO (2 g/L), respectively, and was much higher than those of bare nHAp or GO. After doping of GO on nHAp, the specific surface area of nHAp was increased by 2.5 times. The presence of sulphur peak in EDX spectrum and S-O stretching vibration peak in FTIR confirmed the adsorption of dyes on the surface of nHAp@GO composite. After the adsorption process, the shifting of d((100)) spacing of nHAp confirmed the loading of bulky organic moieties on nHAp@GO composite. Maximum CR and TB dyes adsorption occurred in a wide range of initial pH between 3.0 and 10.0. The adsorption of both CR and TB dyes are due mainly to the electrostatic interaction, pi - pi stacking interaction, hydrophobic interaction, and hydrogen bonds between dyes and nHAp@GO composite. The nHAp@GO nanocomposite was recycled up to three times at the sustained efficiency after washing with ethanol solution. We believe that such multifunctional material developed in this study will be effectively used for the depollution of toxic diazo dyes in practical applications. (C) 2018 Elsevier B.V. All rights reserved.</P>

Genetic diversity and population structure assessment of Hellenia speciosa from Indian agro-ecological regions using inter-simple sequence repeat markers

Prabhu Kamasamudra N.,Rodrigues Vereena,Kumar Amit,Kumar Manish,Srivastava Sharad,Shukla Ashutosh K.,Sundaresan Velusamy 한국원예학회 2023 Horticulture, Environment, and Biotechnology Vol.64 No.2

Hellenia speciosa (J. Koenig) S. R. Dutta (Syn: Costus speciosus (J. Koenig) Sm.) is well known for its anti-diabetic proper- ties and is in high demand for its steroidal sapogenin, diosgenin, which is used in the pharmaceutical industry for manufac- turing steroidal drugs. The increasing demand for this plant has led to the depletion of its wild population. This study was conducted to reveal the genetic diversity of H. speciosa collected from various agro-ecological regions of India for use in devising conservational strategies, and cultivation and breeding programs. Twenty inter-simple sequence repeat markers yielded 304 products with 100% polymorphism demonstrating high genetic diversity. Nei′s gene diversity and Shannon information indexes were estimated among the populations as 0.19 ± 0.23 and 0.28 ± 0.25, respectively. High genetic dif- ferentiation ( GST = 0.40) and low gene fl ow ( Nm = 0.74) were observed, which corroborated with the analysis of molecular variance revealing maximum (86.75%) variance within populations. The unweighted pair group method with arithmetic mean analysis grouped all accessions into three major clusters. Principal component analysis showed that the fi rst three compo- nents accounted for 30.66%, 4.54%, and 3.98% variation, respectively, and Bayesian clustering through structure showed the presence of two genetic population (K = 2). This study revealed high genetic diversity among the populations collected from high altitude compared to those from the plain. A positive but low correlation among genetic and geographic distances was obtained ( r = 0.282, p < 0.0001). Identifi cation of genetic diversity and intra population variation of a species are prime factors to take defi ned conservation strategies.

Lead-free inorganic metal perovskites beyond photovoltaics: Photon, charged particles and neutron shielding applications

Prabhu Srilakshmi,Bharadwaj Dhanya Y.,Bubbly S.G.,Gudennavar S.B. 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.3

Over the last few years, lead-free inorganic metal perovskites have gained impressive ground in empowering satellites in space exploration owing to their material stability and performance evolution under extreme space environments. The present work has examined the versatility of eight such perovskites as space radiation shielding materials by computing their photon, charged particles and neutron interaction parameters. Photon interaction parameters were calculated for a wide energy range using PAGEX software. The ranges of heavy charged particles (H, He, C, N, O, Ne, Mg, Si and Fe ions) in these perovskites were estimated using SRIM software in the energy range 1 keVe10 GeV, and that of electrons was computed using ESTAR NIST software in the energy range 0.01 MeVe1 GeV. Further, the macroscopic fast neutron removal cross-sections were also calculated to estimate the neutron shielding efficiencies. The examined shielding parameters of the perovskites varied depending on the radiation type and energy. Among the selected perovskites, Cs2TiI6 and Ba2AgIO6 displayed superior photon attenuation properties. A 3.5 cm thick Ba2AgIO6-based shield could reduce the incident radiation intensity to half its initial value, a thickness even lesser than that of Pb-glass. Besides, CsSnBr3 and La0.8Ca0.2Ni0.5Ti0.5O3 displayed the highest and lowest range values, respectively, for all heavy charged particles. Ba2AgIO6 showed electron stopping power (on par with Kovar) better than that of other examined materials. Interestingly, La0.8Ca0.2Ni0.5Ti0.5O3 demonstrated neutron removal cross-section values greater than that of standard neutron shielding materials - aluminium and polyethylene. On the whole, the present study not only demonstrates the employment prospects of eco-friendly perovskites for shielding space radiations but also suggests future prospects for research in this direction