Cavitation resistance of concrete containing different material properties

Kumar, G.B. Ramesh,Bhardwaj, Arjit,Sharma, Umesh Kumar Techno-Press 2018 Advances in concrete construction Vol.6 No.1

In the present investigation, influence of various material parameters on the cavitation erosion resistance of concrete was investigated on the basis of laboratory experiments. As there is no well-established laboratory test method for evaluating the cavitation resistance of concrete, a test set up called 'cavitation jet' was specially established in the present study in order to simulate the cavitation phenomenon experienced in the hydraulic structures. Various mixtures of concrete were designed by varying the grade of concrete, type and quantity of pozzolana, type of aggregates and cement type to develop good cavitation resistant concrete constructed using marginal aggregates. Three types of aggregates having three different Los Angeles abrasion values (less than 30%, between 30% and 50% and more than 50%) were employed in this study. To evaluate the cavitation resistance a total of 60 cylindrical specimens and 60 companion cubes were tested in the laboratory respectively. The results indicate that cavitation resistance of concrete degrades significantly as the L.A. abrasion value of aggregates goes beyond the 30% value. Incorporation of pozzolanic admixtures was seemed to be beneficial to enhance the cavitation resistance of concrete. Influence of other material parameters on the cavitation resistance of concrete was also noted and important observations have been made in the paper.

Synergistic effect of Cr2O3 and Co3O4 nanocomposite electrode for high performance supercapacitor applications

Maheshwaran G.,Seethalakshmi G.,Kousalya Devi V.,VenkataKrishna Lappasi Mohanram,Ramesh Prabhu M.,Krishna Kumar M.,Sudhahar S. 한국물리학회 2022 Current Applied Physics Vol.36 No.-

The fabrication of high performance supercapacitor electrodes has been greatly investigated for future high power storage applications. In this present work, chromium oxide-cobalt oxide based nanocomposite (Cr2O3–Co3O4 NC) was synthesized using the hydrothermal approach. Moreover, the cyclic voltammetry (CV) study reveals the Cr2O3–Co3O4 NC delivers a high specific capacitance of 619.4 F/g at 10 mV/s. The electrochemical impedance spectra (EIS) of Cr2O3–Co3O4 NC possess the solution resistance (Rs) and charge transfer resistance (Rct) of 0.68 Ω and 0.03 Ω respectively. The Galvanostatic charge-discharge (GCD) analysis demonstrated the prolonged charge-discharge time and good rate capability of the Cr2O3–Co3O4 NC. The cyclic stability of Cr2O3–Co3O4 NC delivers superior capacitive retention of 83% even after 2000 cycles. The asymmetric supercapacitor (ASC) device based on Cr2O3–Co3O4//AC yielded an energy density of 4.3 Wh/kg at the corresponding power density of 200 W/kg. Furthermore, the ASC delivers superior cyclic stability of 74.8% even after 1000 consecutive charge-discharge cycles.

Extraction and characterization of collagen from the skin of Pterygoplichthys pardalis and its potential application in food industries

Ramesh Nurubhasha,N. S. Sampath Kumar,Satish K. Thirumalasetti,G. Simhachalam,Vijaya R. Dirisala 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.6

The primary objective of this study was toextract collagen from underutilized fish species owing to itscost effective nature and also its ability to address thedemand of type I collagen arising from food and pharmaceuticalindustries. Acid and pepsin soluble collagen(ppASC and ppPSC) were extracted from the skin of suckercatfish (Pterygoplichthys pardalis) with a yield of 19.6 and23.8% on wet weight basis respectively. The same werecharacterized and confirmed as type I collagen by SDS–PAGE, FTIR and UV–Vis spectroscopy, amino acid analysis,and Zeta potential. Taking into consideration theapplication of collagen in food industry, a food product wasdeveloped by incorporating with fresh cheese. This fortificationwas found to be acceptable and had not altered thetaste, odor and other sensory properties of the product.

Performance and emission characteristics of a low heat rejection spark ignited engine fuelled with E20

C. Ramesh Kumar,G. Nagarajan 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.4

In internal combustion engines, the concept of low heat rejection (LHR) using thermal barrier coating on the surface of combustion chamber is gaining attention. Thermal barrier coating reduces the heat transfer to the cooling system, protects engine components from peak heat flux and fluctuating temperature produced during combustion and improves the performance of the engine. Information in the literature is plentiful for LHR diesel engine and only few studies exist on LHR spark ignited engine. The application of thermal barrier coating in spark ignited engine is limited by pre-ignition and knocking due to elevated combustion chamber temperature. A spark ignited engine with moderate insulation on the combustion chamber and higher octane fuel can overcome this difficulty. The objective of the present experimental study is to quantify the changes in performance and emission characteristics brought by partial thermal insulation on the combustion chamber of a four stroke spark ignited engine fueled with E20 blend. Partial thermal insulation was created by coating 0.3 mm thick Alumina (Al2O3) on the cylinder head, inlet and exhaust valves. The changes are quantified with respect to unmodified engine fueled with gasoline. The combustion parameters such as flame development and rapid burn duration are also estimated and compared. The results indicate that partially insulated SI engine when fueled with E20 improves performance and reduces emission. A maximum of 48% reduction in THC and 50% reduction in CO emission at part load was achieved.

A 2D Analytical Modeling of Single Halo Triple Material Surrounding Gate (SHTMSG) MOSFET

P. Suveetha Dhanaselvam,N. B. Balamurugan,G. C. Vivek Chakaravarthi,R. P. Ramesh,B. R. Sathish Kumar 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.4

In the proposed work a 2D analytical modeling of single halo Triple material Surrounding Gate (SH-TMSG) MOSFET is developed. The Surface potential and Electric Field has been derived using parabolic approximation method and the simulation results are analyzed. The essential substantive is provided which elicits the deterioration of short channel effects and the results of the analytical model are delineated and compared with MEDICI simulation results and it is well corroborated.

Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications

B. Sivakumar,S. Gokul Raj,G. Ramesh Kumar,R. Mohan 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

Single crystals of lithium potassium phthalate (LiKP) were successfully grown from aqueous solution by solvent evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction. The lithium potassium phthalate C16 H12 K Li3 O11 belongs to triclinic system with the following unit-cell dimensions at 298(2) K; a = 7.405(5) Å; b = 9.878(5) Å; c = 13.396(5) Å; α = 71.778(5)°; β = 87.300(5)°; γ = 85.405(5)°; having a space group P1. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurs in the compound. Thermal stability of the crystal was also studied by both simultaneous TGA/DTA analyses. The UV-Vis-NIR spectrum shows a good transparency in the whole of Visible and as well as in the near IR range. Third order nonlinear optical studies have also been studied by Z-scan technique. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results have been discussed in detail.

Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications

Sivakumar, B.,Raj, S. Gokul,Kumar, G. Ramesh,Mohan, R. Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

Single crystals of lithium potassium phthalate (LiKP) were successfully grown from aqueous solution by solvent evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction. The lithium potassium phthalate $C_{16}\;H_{12}\;K\;Li_3\;O_{11}$ belongs to triclinic system with the following unit-cell dimensions at 298(2) K;$a=7.405(5){\AA}$;$b=9.878(5){\AA}$;$c=13.396(5){\AA}$;${\alpha}=71.778(5)^{\circ}$;${\beta}=87.300(5)^{\circ}$;${\gamma}=85.405(5)^{\circ}$; having a space group P1. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurs in the compound. Thermal stability of the crystal was also studied by both simultaneous TGA/DTA analyses. The UV-Vis-NIR spectrum shows a good transparency in the whole of Visible and as well as in the near IR range. Third order nonlinear optical studies have also been studied by Z-scan technique. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results have been discussed in detail.

A 2D Analytical Modeling of Single Halo Triple Material Surrounding Gate (SHTMSG) MOSFET

Dhanaselvam, P. Suveetha,Balamurugan, N.B.,Chakaravarthi, G.C. Vivek,Ramesh, R.P.,Kumar, B.R. Sathish The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.4

In the proposed work a 2D analytical modeling of single halo Triple material Surrounding Gate (SH-TMSG) MOSFET is developed. The Surface potential and Electric Field has been derived using parabolic approximation method and the simulation results are analyzed. The essential substantive is provided which elicits the deterioration of short channel effects and the results of the analytical model are delineated and compared with MEDICI simulation results and it is well corroborated.

Design and development of enhanced criticality alarm system for nuclear applications

Padi Srinivas Reddy,R. Amudhu Ramesh Kumar,M. Geo Mathews,G. Amarendra 한국원자력학회 2018 Nuclear Engineering and Technology Vol.50 No.5

Criticality alarm systems (CASs) are mandatory in nuclear plants for prompt alarm in the event of anycriticality incident. False criticality alarms are not desirable as they create a panic environment for radiationworkers. The present article describes the design enhancement of the CAS at each stage andprovides maximum availability, preventing false criticality alarms. The failure mode and effect analysisare carried out on each element of a CAS. Based on the analysis, additional hardware circuits aredeveloped for early fault detection. Two different methods are developed, one method for channel loopfunctionality test and another method for dose alarm test using electronic transient pulse. The designenhancement made for the external systems that are integrated with a CAS includes the power supply,criticality evacuation hooter circuit, radiation data acquisition system along with selection of differentsoft alarm set points, and centralized electronic test facility. The CAS incorporating all improvements areassembled, installed, tested, and validated along with rigorous surveillance procedures in a nuclear plantfor a period of 18,000 h.

Isopod Parasite Induced Secondary Microbial Infection in Marine Food Fishes

( Ravichandran S ),( K Sivasubramanian ),( P Parasuraman ),( D. Karthick Rajan ),( G. Ramesh Kumar ) 한국어병학회 2016 한국어병학회지 Vol.29 No.1

Isopods are parasitic crustaceans that pose serious threat to fisheries. Several studies have tried to explore the host-pathogen relationship between marine fishes and isopods. The present study aims to understanding the secondary infections in marine fishes pertaining to isopods. To assess the secondary infection in infected fishes, parasite infested and healthy tissues of fishes were collected. The samples were subjected to standard microbiological procedure to identify the presence of pathogenic bacteria and fungi. Our results showed the branchial region had the higher microbial load of non-sporulating cenocytic fungi in infected fishes. Moreover, fungal strains isolated from the parasitic lesion confirmed that the parasitation and body lesion facilitates the entry of several pathogenic microbes at the damaged host tissue. More over the immune regulation of fish fights back by producing minute cysts, trying to encapsulate the growing fungus. But this may eventually lead to systemic infestation and death of the fish.