Modal parametric changes in a steel bridge with retrofitting

Suresh Kumar Walia,Hemant Kumar Vinayak,Ashok Kumar,Raman Parti 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.2

This paper presents the status improvement of an old damaged deck type rural road steel truss bridge through the modal parametric study after partial retrofitting. The dynamic and static tests on bridge were carried out as in damaged state and after partial retrofitting. The dynamic testing on the steel bridge was carried out using accelerometers under similar environmental conditions with same speed of the moving vehicle. The comparison of the modal parameters i.e., frequency, mode shape mode shape curvature, modal strain energy, along with the deflection parameter are studied with respect to structural analytical model parameters. The status up gradation for the upper and downstream truss obtained was different due to differential level of damage in the bridge. Also after retrofitting the structural elemental behavior obtained was not same as desired. The damage level obtained through static tests carried out using total station indicated further retrofitting requirement.

Propagation of plane waves in an orthotropic magneto-thermodiffusive rotating half-space

Suresh Kumar Sheokand,Rajesh Kumar,Kapil Kumar Kalkal,Sunita Deswal 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.4

The present article is aimed at studying the reflection phenomena of plane waves in a homogeneous, orthotropic, initially stressed magneto-thermoelastic rotating medium with diffusion. The enuciation is applied to generalized thermoelasticity based on Lord-Shulman theory. There exist four coupled waves, namely, quasi-longitudinal P-wave (qP), quasi-longitudinal thermal wave (qT), quasi-longitudinal mass diffusive wave (qMD) and quasi-transverse wave (qSV) in the medium. The amplitude and energy ratios for these reflected waves are derived and the numerical computations have been carried out with the help of MATLAB programming. The effects of rotation, initial stress, magnetic and diffusion parameters on the amplitude ratios are depicted graphically. The expressions of energy ratios have also been obtained in explicit form and are shown graphically as functions of angle of incidence. It has been verified that during reflection phenomena, the sum of energy ratios is equal to unity at each angle of incidence. Effect of anisotropy is also depicted on velocities of various reflected waves.

Prediction of pressure equalization performance of rainscreen walls

Kumar, K. Suresh,van Schijndel, A.W.M. Techno-Press 1999 Wind and Structures, An International Journal (WAS Vol.2 No.4

In recent years, rainscreen walls based on the pressure equalization principle are often used in building construction. To improve the understanding of the influence of several design parameters on the pressure equalization performance of such wall systems, a theoretical consideration of the problem may be more appropriate. On this basis, this paper presents two theoretical models, one based on mass balance and the other based on the Helmholtz resonator theory, for the prediction of cavity pressure in rigid rainscreen walls. New measures to assess the degree of pressure equalization of rainscreen walls are also suggested. The results show that the model based on mass balance is sufficiently accurate and efficient in predicting the cavity pressure variations. Further, the performance of the proposed model is evaluated utilizing the data obtained from full-scale tests and the results are discussed in detail.

Subcutaneous pharmacokinetics and dosage regimen of cefotaxime in buffalo calves (Bubalus bubalis)

Suresh Kumar Sharma,Anil Kumar Srivastava 대한수의학회 2006 Journal of Veterinary Science Vol.7 No.2

Electrochemical synthesis and surface protection of polypyrrole-CeO₂ nanocomposite coatings on AA2024 alloy

Kumar, A. Madhan,Babu, R. Suresh,Ramakrishna, Suresh,de Barros, Ana L.F. Elsevier 2017 Synthetic metals Vol.234 No.-

<P><B>Abstract</B></P> <P>A facile approach based on electrochemical polymerization was used to synthesize polypyrrole/CeO<SUB>2</SUB> (PPy/CeO<SUB>2</SUB>) nanocomposite on an AA2024 alloy surface. CeO<SUB>2</SUB> nanoparticles (NPs) embedded in the PPy matrix were observed using FESEM micrographs with EDX analysis. IR and UV–vis spectroscopy were used to characterize the synthesized PPy/CeO<SUB>2</SUB> nanocomposite. The Raman spectra reflected the interactions between the π-conjugated structure of PPy and CeO<SUB>2</SUB> NPs. TGA thermograms revealed improved thermal stability of the synthesized nanocomposite and were used to determine the amount of nano ceria incorporated in the PPy matrix. The electrochemical corrosion behavior of the coated alloys in 0.6M NaCl solution was examined through potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) measurements. From these electrochemical studies, a larger shift of E<SUB>corr</SUB> in the positive direction with a high amount of CeO<SUB>2</SUB> in the nanocomposite was obtained, as well as a maximum corrosion protection efficiency of 99.64% by incorporating 3% of CeO<SUB>2</SUB> NPs in the PPy coatings. EIS studies also confirmed the enhanced corrosion protection behavior of PPy/CeO<SUB>2</SUB> coatings with higher R<SUB>ct</SUB>, R<SUB>f</SUB> and lower CPE<SUB>dl</SUB> values compared to those of pure PPy coatings. The results showed that the PPy coatings with CeO<SUB>2</SUB> nanoparticles can be potential coating materials for the corrosion protection of AA2024 alloys substrates.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polypyrrole coatings with nanoceria were prepared through electrochemical route. </LI> <LI> Raman studies confirm the interaction between π-conjugated PPy & nano CeO<SUB>2</SUB>. </LI> <LI> TGA reveals improved thermal stability of the synthesized nanocomposite. </LI> <LI> Uniform distribution of nano CeO<SUB>2</SUB> was confirmed by EDX mapping analysis. </LI> <LI> Corrosion test confirms better surface protection of PPy/Ce than pure PPy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Plasma proteome analysis for anti-obesity and anti-diabetic potentials of chitosan oligosaccharides in ob/ob mice

Kumar, Suresh G.,Rahman, Md. Atiar,Lee, Sung Hak,Hwang, Hee Sun,Kim, Hyun Ah,Yun, Jong Won WILEY-VCH Verlag 2009 Proteomics Vol.9 No.8

<P>Altered levels of adipokines, derived as a result of distorted adipocytes, are the major factors responsible for changing biochemical parameters in obesity that leads to the development of metabolic disorders such as insulin resistance and atherosclerosis. In our previous reports, chitosan oligosaccharides (CO) were proved to inhibit the differentiation of 3T3-L1 adipocytes. In the present study, an attempt was made to investigate the anti-obesity and anti-diabetic effect of CO on ob/ob mice, by means of differential proteomic analysis of plasma. This was followed by immunoblotting, and gene expression in adipose tissue to clarify the molecular mechanism. CO treatment showed reduced diet intake (13%), body weight gain (12%), lipid (29%) and glucose levels (35%). 2-DE results showed differential levels of five proteins namely RBP4, apoE, and apoA-IV by >2-fold down-regulation and by >2-fold of apoA-I and glutathione peroxidase (GPx) up-regulation after CO treatment. Immunoblotting studies of adiponectin and resistin showed amelioration in their levels in plasma. Furthermore, the results of gene expressions for adipose tissue specific TNF-α, and IL-6 secretary molecules were also down-regulated by CO treatment. Gene expressions of PPARγ in adipose tissue were in good agreement with the ameliorated levels of adipokines, thereby improving the pathological state. Taken together, CO might act as a potent down-regulator of obesity-related gene expression in ob/ob mice that may normalize altered plasma proteins to overcome metabolic disorders of obesity.</P>

Generation of local wind pressure coefficients for the design of low building roofs

Kumar, K. Suresh,Stathopoulos, Ted Techno-Press 2001 Wind and Structures, An International Journal (WAS Vol.4 No.6

This paper presents recent research on the experimental evaluation of wind loads on low buildings and the recommendations provided in the form of traditional codification. These mainly include the wind loads on buildings with geometries different from those examined in previous studies. This is followed by the evaluation of simulated wind loads on low building roofs. The overall application of a recently proposed simulation methodology for codification purposes is discussed in detail. The traditional codification provides for a group of roof geometries a single peak design pressure coefficient for each roof zone considering a nominal worst-case scenario; this may often lead to uneconomical loads. Alternatively, the presented methodology is capable of providing peak pressure coefficients corresponding to specific roof geometries and according to risk levels; this can generate risk consistent and more economical design wind loads for specific roof configurations taking into account, for instance, directional design conditions and upstream roughnesses.

Pressure equalization of rainscreen facades: Analysis of the field data in the frequency domain

Kumar, K. Suresh,Wisse, J.A. Techno-Press 2001 Wind and Structures, An International Journal (WAS Vol.4 No.2

This paper reports the field measurements concerning pressure equalization of rainscreen facades carried out at the Technical University of Eindhoven (TUE) in the Netherlands. The field facility including the details of test panel, meteorological tower, instrumentation, data collection and analysis is presented. Results of investigations into cavity response for various leakage and venting configurations are discussed. Frequency domain techniques have been utilized to show the influence of wind as well as facade characteristics on the pressure equalization performance. Further, this paper presents an early attempt to synthesize the experimental results into existing building codes.

On the Breeding of “CSR18${\times}$CSR19”- A Robust Bivoltine Hybrid of Silkworm, Bombyx mori L. for the Tropics

Kumar, N.Suresh,Basavaraja, H.K.,Kumar, C.M.Kishor,Reddy, N.Mal,Datta, R.K. Korean Society of Sericultural Science 2002 International Journal of Industrial Entomology Vol.5 No.2

Earlier breeding experiments undertaken at Central Sericultural Research and Training Institute, Mysore, India since a decade had resulted in the development of many productive and qualitatively superior bivoltine hybrids. However, the hot climatic conditions of tropics prevailing particularly in summer are not conducive to rear these high yielding bivoltine hybrids. This has necessitated breeding of compatible bivoltine hybrids for year-round rearing. Accordingly, the Japanese hybrid, B2Ol ${\times}$ BCS12 which was found to be tolerant to high temperature was used as breeding resource material. Following hybridization and selection rearing of silkworms was taken up in SERICATRON (Environmental chamber with precise and automatic control facilities for uniform maintenance of temperature and humidity) at high temperature of $36{\times}1^{\circ}C$ and 85${\times}$5% RH in fifth instar and the control batches at $25{\times}1^{\circ}C$ and 65{\times}$5% RH. Directional selection was resorted to the batches reared at 36$\pm$1$^{\circ}C$ till F$_{5}$ keeping pupation rate as important selection criteria. From $F_{2}% onwards the experiment was modified in such a way as to conduct normal rearing every alternate generation to regain the lost vitality due to continuous exposure to high temperature and high humidity stress. At $F_{2}$ , Oval and dumb-bell cocoons were separated out and designated as CSR18 and CSR19, respectively. By utilizing these lines at $F_{12}$, the hybrid CSR18$\times$CSR19 was prepared and studied for the thermotolerance by subjecting to stress condition at high temperature of 36$\pm$1$^{\circ}C$ and 85$\pm$5% RH in fifth instar and the control batches at $25{\times}1^{\circ}C$ and 65${\times}$5% RH. The better performance of CSR18${\times}$CSR19 (survival > 88%) at $36{\times}1^{\circ}C$ clearly indicates the general superiority of CSR18${\times}$CSR19 with regard to high temperature tolerance over the productive hybrids and CSR18$\times$CSR19 can perform well in varied agro-climatic conditions of the tropics with optimum qualitative and quantitative characteristics.s.

Spectral density functions of wind pressures on various low building roof geometries

Kumar, K. Suresh,Stathopoulos, T. Techno-Press 1998 Wind and Structures, An International Journal (WAS Vol.1 No.3

This paper describes in detail the features of an extensive study on Spectral Density Functions (SDF's) of wind pressures acting on several low building roof geometries carried out in a boundary layer wind tunnel. Various spectral characteristics of wind pressures on roofs with emphasis on derivation of suitable analytical representation of spectra and determination of characteristic spectral shapes are shown. Standard spectral shapes associated with various zones of each roof and their parameters are provided. The established spectral parameters can be used to generate synthetic spectra adequate for the simulation of wind pressure fluctuations on building surfaces in a generic fashion.