- S. Manikandan
- S. Ramanathan
- S. Jegannathan
- M. Briget Mary
- S. Thangadurai
- S. Jayaprakash
- H. P. Patil
- B. Basavanagoud
- D. Kumar
- M. Narayana Rao
- A. Gopala Reddy
- A. Rajasekher Reddy
- C. Haritha
- M. Anandaraj
- P. Parameswaran
- S. Krishnakumar
- T. Ezhilarasi
- V. Thomas Paul
- R. Thirumurugesan
- S. Chandramouli
- G. Padmakumar
- Shaju K. Albert
- B. K. Nashine
- V. Prakash
- P. Selvaraj
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Ramakrishnan, V.
- A Calorimetric Study of Ti-6AL-4V Alloy
Authors
1 Department of Mechanical Engineering, Annamalai University, IN
2 Department of Manufacturing Engineering, Annamalai University, IN
3 Thermal Systems Group, ISRO Satellite Centre, Bangalore, IN
Source
Indian Journal of Science and Technology, Vol 6, No 4 (2013), Pagination: 4262-4267Abstract
Ti-6Al-4V titanium alloy is widely used in industrial applications such as aeronautic and aerospace due to its good mechanical properties at high temperatures. The aim of the work is to determine the heat capacity of the thermal cycled titanium alloy. The cylindrical specimens of dimension 3 ± 0.1 mm in diameter and 2.5 ± 0.1 mm in length were machined from the CNC machine. The specimens were subject to two different types of heat treatments (Solution treated and annealed). First type of heat treatment (annealing) is processed by heating the specimen to a temperature of 7500°C for 4 hours and it is cooled in the furnace to reach the atmospheric temperature. Second type of heat treatment (solution treating) is processed by the specimen is heated to a temperature of 975°C for 1 hour and it is quenched in a solution containing water with 5% of caustic soda. After quenching (delay of 6 second), aging was done at 450° C for 4 hours and then it is furnace cooled to reach atmospheric temperature The heat treated specimens were thermal cycled in a specially designed thermal cycling apparatus for different cycles heat flow and the flow of energy into or out of the sample as a function of temperature was measured by using Differential Scanning Calorimetry (DSC). The heat flow response is recorded as a function of actual sample temperature range from -120° C to 380° C. The measurements of the heat capacity by DSC with an accuracy of ±2% have been reported. This study restrict the use of DSC as a truly quantitative calorimetric technique and concentrates mainly on the practical set of experimental heat capacity data measured over a temperature range for different aerospace materials being used/developed indigenously for the Indian Space Programme.Keywords
Thermal Analysis, Differential Scanning Calorimeter, Specific Heat, Heat TreatmentReferences
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- Lam T T, ed. (1998). Study of advanced satellite thermal management technology, Aerospace Corporation, TOR-98(1057)-2.
- Geng H and He S (1997). Thermal cycling behavior of As-Quenched and aged Ti-6Al-4V alloy, Metallurgical and Material Transactions A, vol 28(9), 1809-1814.
- ASM International (1994). Material Properties Handbook: Titanium Alloys.
- Karthikeyan B, Ramanathan S et al. (2010). A calorimetric study of 7075Al/SiCp composites. International Journal of Materials and Design, vol 31(supplement 1), S92-S95.
- Ramakrishnan V, Ramasamy A et al. (2002). Characterisation of MMCs by thermophysical measurements 16th National Heat and Mass Transfer Conference & 5th Indian Society for Heat and Mass Transfer/American Society of Mechanical Engineers Heat and Mass Transfer Conference, Calcutta, India, January, 216-222.
- Karthikeyan B, Ramanathan S et al. (2010). Specific heat capacity measurement of Al/SiCp composites by differential scanning calorimeter, Advanced Materials Research, vols 264-265, 669-674.
- Basak D, Overfelt R A et al. (2003). Measurement of specific heat capacity and electrical resistivity of industrial alloys using pulse heating techniques, International Journal of Thermophys, vol 24(6), 1721-1733.
- Kaschnitz E, Reiter P et al. (2002). Thermal expansion of liquid Ti-6Al-4V measured by electrostatic levitation, International Journal of Thermophysics, vol 23, 267.
- Basak D, Boetinger W J et al. (1999). Effect of heating rate and grain size on the melting behavior of the alloy Nb-47 mass% Ti in pulse-heating experiments, Acta Materialia vol 47(11), 3147-3158.
- Basak D, Kattner U R et al. (2000). Application of laser polarimetry to the measurement of specific heat capacity and enthalpy of the alloy 53nb-47ti (mass%) in the temperature range 1600 to 2000 k by a millisecond-resolution pulse heating technique, International Journal of Thermophysics vol 21(4), 913-926.
- Brooks C R (1982). Heat treatment, structure and properties of nonferrous alloys, American Society of Metals, Metals Park, Ohio, 361.
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- Vibrational Spectral Studies of Nicotinium Picrate
Authors
1 Department of Laser Studies, School of physics, Madurai Kamaraj University, Madurai,-625021, IN
2 Post Graduate Studies and Research Department of Physics, Lady Doak College, Madurai,-625021, IN
3 Post Graduate Studies and Research Department of Chemistry, Raja Doraisingam Government Arts College, Sivagangai-630 561, IN
Source
Asian Journal of Research in Chemistry, Vol 6, No 7 (2013), Pagination: 645-649Abstract
This article describes the vibrational spectra of nicotinium picrate. The Infrared and Raman Spectra were recorded at room temperature for nicotinium picrate and the observed bands were assigned. In nicotinium picrate compound nicotinium is the cation and picrate forming the anion. The N−H···O and O−H···N hydrogen bonds were observed in both infrared and Raman spectra. The structure is also stabilized by C−H···O hydrogen bonding. These hydrogen bonds link the layers of cation with the layers of anions. Nicotinic acid is also known as 3-pyridine carboxylic acid. Picrate being the trinitrophenolate has the characteristic bands of phenol. The nitro group and the phenoxy group stretching are observed in both infrared and Raman spectra. These suggest that the picrate ion is unaffected by the presence of the cations. Factor group analysis has been made and the numbers of vibrational modes have been calculated. The tentative assignments of the observed bands are given.Keywords
Nicotinium Picrate, Infrared Spectra, Raman Spectra, Intermolecular Hydrogen Bonding, Factor Group AnalysisReferences
- Gielen M, Kholufi AE,.Biesemans M, Willem R and Meunier- Piret J. (2-Methylthio-3-Pyridinecarboxylato)-diethyltin and -din- butyltin compounds: synthesis, spectroscopic characterization and in vitro antitumour activity. X-ray crystal structure of bis[diethyl(2-methylthio-3-Pyridinecarboxylato)tin] oxide and of diethyltin bis(2-methylthio-3-pyridinecarboxylate). Polyhedron. 11(15); 1992 :1861.
- Seeman J I. Using Basic Principles to Understand Complex Science: Nicotine Smoke. Journal of Chemical Education. 82; 2005:1577-1583.
- Wright WB and King GSD. The crystal structure of nicotinic acid. Acta Crystallographica. 6 (4); 1953: 305-317
- Kutoglu A and Scheringer C. Nicotinic acid, C6H5NO2: refinement. Acta Crystallographica Section C. 39; 1983: 232- 234.
- Edsall JT. Raman Spectra of Amino Acids and Related Substances III. Ionization and Methylation of the Amino Group. Journal of Chemical Physics. 5(4); 1937:225-238.
- Bulut A, Yesilel O Z., Dege N., Icbudak H, Olmez H and Buyukgung or Dinicotinamidium squarate. Acta Crystallographica Section C. 59; 2003: o727-o729.
- Krishnaswamy S., Pattabhi V and Guru Row TN. Nicotinoylglycine, a metabolic product. Acta Crystallographica Section C. 43 (4); 1987:.728-729.
- Giantsidis J and Turnbull M M. 6-Aminonicotinic acid hydrochloride. Acta Crystallographica Section C.56 (3); 2000: 334-335.
- Soriano-Garcia M, Toscano R A and Espinosa G. Crystal and molecular structure of kinetin picrate: a new tautomeric form of N(6)-substituted purine. Journal of Crystallographic and Spectroscopic Research. 15 (6); 1985: 651-655
- Anitha K , Athimoolam S and Rajaram RK. Nicotinium picrate. Acta Crystallographica Section E. 61; 2005: o2556-o2558.
- Priyanka Singh, Singh N.P and Yadav R.A. Quantum Mechanical Studies of Conformers, Molecular Structures and Vibrational Characteristics of Heterocyclic organics: Nicotinic acid and 2-Fluoronicotinic acid. Journal of Chemical and Pharmaceutical Research. 3(1); 2011: 737-755.
- Pandiarajan S, Uma Devi M, Briget Mary M,.Rajaram RK and Ramakrishnan V. Infrared and Raman spectroscopic studies of Lmethioninium nitrate. Journal of Raman Spectroscopy. 35 (11); 2004: 907-913.
- Senthilkumar S, Briget Mary M and Ramakrishnan V. Infrared and Raman spectroscopic studies of L-valinium picrate. Journal of Raman Spectroscopy. 38 (3) ;2007: 288-294.
- Schmidt A., Lindner A S, Casado J and Ramírez F J. Vibrational spectra and quantum chemical calculations of uracilyl– pyridinium mesomeric betaine . Journal of Raman Spectroscopy. 38 (11); 2007: 1500-1509.
- Cinta S, Morari C, Vogel E, Maniu D, Aluas M, Iliescu T, Cozar O and Kiefer W. Vibrational studies of B-6 vitamin. Vibrational Spectroscopy. 19 (2); 1999: 329-334.
- Uma Devi T, Lawrence N, Ramesh Babu R, Ramamurthi K and Bhagavannarayana G. Studies on L-valinium Picrate Single Crystal: A Promising NLO, Crystal Journal of Minerals & Materials Characterization & Engineering, 8; 2009: 393-403.
- Beulah J, Rajkumar M and Ramakrishnan V. Vibrational spectroscopic study of DL-methionine dihydrogen phosphate. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 57 (2); (2001) 247-254.
- Briget Mary M, Sasirekha V and Ramakrishnan V. Vibrational spectral analysis of DL-valine DL-valinium and DL-methionine DL-methioninium picrates. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 65 (3-4); 2006; 955- 963.
- Szafran M, Katrusiak A and Dega-Szafran Z. Hydrogen bonds and conformational analysis of bis(1-methylisonicotinate) hydrochloride monohydrate by X-ray diffraction, vibrational spectra and B3LYP calculations. Journal of Molecular Structure.794 (1-3); 2006: 46-53.
- Zea BemudeZ V de, Carlos LD, Silva MM and Smith MJ. An interesting ligand for the preparation of luminescent plastics: The picrate ion. Journal of Chemical Physics. 112; 2000: 3293-3314.
- A New Single-stage Solar Based Controlled Full-bridge DC-DC Converter
Authors
1 Sathyabama University, Chennai-600119, Tamilnadu, IN
2 Department of EEE, Madha Engineering College, Chennai-600069, Tamilnadu, IN
Source
Indian Journal of Science and Technology, Vol 7, No 9 (2014), Pagination: 1382-1386Abstract
This paper presents a new Single-stage solar based controlled full-bridge DC-DC converter. Solar model is connected on the input side and from the solar model some voltage is received. The circuit has two full wave converters connected. While the first converter acts as an inverter, the second converter functions as a rectifier in-between connected step-up transformer. Controlled converter is used to load side besides a capacitive filter being connected. Finally inductive load is connected to output side. Output voltage and output current are measured. Compared with normal voltage, this converter's source cost is less because in this work input side solar panel is used. The circuit with all the component parameters will operate at zero-voltage switching which retains the high circuit efficiency.Keywords
Full-Bridge Converter, IGBT, Index Terms - Buck-Boost Converter, MOSFET, Power Factor Correction (PFC), Single-Stage, ZCS, Zero-Voltage Switching (ZVS), ZVZC.- Graph Equations Involving Line Graphs, Middle Graphs and Mediate Graphs
Authors
1 Department of Mathematics, Pondicherry University, Puducherry - 605 014, IN
2 Department of Mathematics, Karnatak University, Dharwad - 580 003, IN
Source
The Journal of the Indian Mathematical Society, Vol 81, No 3-4 (2014), Pagination: 309-318Abstract
In this paper, we obtain all pairs (G,H) of graphs satisfying the following graph equations:Keywords
Line Graph, Middle Graph, Mediate Graph, Eulerian, Outer- Planar, Maximal Outerplanar, Minimally Nonouterplanar.References
- L.W. Beineke, Derived graphs and digraphs, Beitrge Zur Graphentheorie, Leipzig, (1968), 17–23.
- T. Hamada and I. Yoshimura, Traversability and connectivity of the middle graph of a graph, Discrete Math., 14 (1976), 247–255.
- F. Harary, Graph Theory, Addison-Wesley, Reading, Mass, 1969.
- H. P. Patil, B. Basavanagoud and V. Ramakrishna, Connectivity, traversability, planarity and coverings in mediate graphs, J. Karnatak Univ. Sci., 2013, 38–48.
- H. Whitney, Congruent graphs and the connectivity of graphs, Amer. J. Math. 54 (1932), 150–168.
- Third Dimensional Computations Using Non Linear Projection Methods in Spherical Projection Plane
Authors
1 Department of Mechanical Engineering, Sri Venkateswara College of Engineering and Technology, Thirupachur, 631 203, IN
2 Sri Sapthagiri Institute of Technology, OOcheri, IN
Source
Automation and Autonomous Systems, Vol 3, No 2 (2011), Pagination: 90-94Abstract
Literature review revealed that attempts were made to apply non-linear projection methods such as perspective projection methods, for computing Z field (Z) or depth field in a given 3D Environment (3DE). Literature also revealed that the study was confined to using Flat Picture Planes (FPP) and Cylindrical Picture Planes (CPP). A high degree of non-linearity was reported between the depth as seen on Flat Picture Planes (FPP) or Cylindrical Picture Planes (CPP) and the actual depth (Z). This non-linearity was reported to be higher for depth (Z) values nearer to and far away from Flat Picture Planes (FPP) or Cylindrical Picture Planes (CPP). This non-linear behavior is mainly due to the Flat and Cylindrical nature of the projection planes. A slight decrease in non-linearity was reported while using CPP. An attempt is made is this paper to use Picture Planes having spherical geometry and to investigate whether the non-linearity further decreases and if so, to quantity the decrease. A set of known Z values are considered and the computer generated graphical model of the Z – field is obtained using FPP & SPP. The depth values as seen on the FPP & SPP namely df & ds are computed. Using numerical methods, nth order equations are proposed between computed depth Zf and df for FPP and Zs and ds for SPP, where Zf and Zs are the computed depths under FPP & SPP methods. The percent variations (pf or ps) of Zf with Z and Zs with Z during the entire region of Z are computed. It has been concluded that SPP method offered the least percent variation and lies with in +5%. Hence with in an accuracy of + 5% of actual depth (Z) the computed depth Zs can be used for depth computations. This model can be suitably interfaced with the kinematic design of Robots, in order that the Robot can generate its own commands for fixing the coordinates of the negotiating objects, with in an accuracy of + 5%.
Keywords
Flat, Spherical and Cylindrical Projection Planes, Depth Field, Method of Least Squares, Perspective Projections.- Evaluation of Iron-induced Oxidative Stress and its Amelioration by Certain Herbs in Broilers
Authors
1 Department of Pharmacology and Toxicology, College of Veterinary Science, Rajendranagar, Hyderabad - 500 030, IN
2 Associate Dean, College of Veterinary Science, Korutla, Andhra Pradesh, IN
Source
Toxicology International (Formerly Indian Journal of Toxicology), Vol 18, No 1 (2011), Pagination: 54-57Abstract
A total of 225 male broiler chicks (Cobb strain) of day-old age were randomly divided into 15 groups consisting of 15 chicks in each group. Group 1 was maintained as basal diet control and group 2 on ferrous sulfate at 0.5% in feed throughout 6 wk as iron toxic control without any treatment. Groups 3-15 were maintained on FeSO4 at 0.5% in feed for the 4 wk (28 days) of study and thereafter administered with different herbs and their combinations for the remaining 2 wk. The blood samples were drawn from wing vein at the end of 4th and 6th weeks from the birds in each group for the assay of superoxide dismutase (SOD) and catalase. Sera samples were separated from the blood for the estimation of alanine transaminase (ALT) and serum creatinine. The birds were sacrificed at the end of 6th wk and tissues were collected for the assay of reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) in liver and kidney homogenates. The activities of SOD, catalase and ALT, and the concentration of TBARS and serum creatinine were increased significantly (P<0.05), while the concentration of tissue GSH was decreased significantly (P<0.05) in all the groups as compared to basal diet control and the values showed significant improvement in groups 3-15 that were treated during the last 2 weeks. It is concluded that iron induces toxicity by generating reactive oxygen species, and antioxidant herbs are useful in treating the iron-induced toxicity.Keywords
Broilers, herbs, iron, oxidative stress- Optimization of Parameters for Welding of Spark Plug Detector
Authors
1 Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN
2 Metallurgy & Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN
Source
Indian Welding Journal, Vol 53, No 1 (2020), Pagination: 67-73Abstract
One of the spark plug leak detectors employed in high temperature liquid sodium systems had failed to detect a sodium leak and systematic failure analysis was carried out to identify the ischolar_main cause of the failure. Radiography image of the leak port nozzle revealed that the extension wire which was welded with spark plug electrode had snapped. Since the failure originated from the cracks present in the weld, it was decided to standardize the welding procedure of spark plug electrode to extension wire to prevent the possibility of similar failures in future. Three different materials viz, stainless steel, nickel, inconel were chosen as extension wires as well as filler wires to optimize the welding parameters. Microstructural studies in terms of presence of defects, interface integrity between the weld and extension wire as well as that of spark plug electrode were carried out. Based on this, the final choice of welding parameters, material for extension wire and for filler wire to achieve a sound weld was proposed.Keywords
Spark Plug Detector, Extension Wire, Failure Analysis, Metallography, Welding Procedure Qualification.References
- Chaudhari R, Parekh R and Ingle A (2014); Reliability of dissimilar metal joints using fusion welding, Int Conf on Machine Learning and Mechanical Engineering (ICMLEME'2014), Dubai, UAE.
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- Ramirez JE, Han B and Liu S (1994); Effect of welding variables and solidification substructure on weld metal porosity, Metal and Mat Trans A, 25, p. 2285.
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- Hidnert P (1957); Thermal expansion of some nickel alloys, Journal of Research of the National Bureau of Standards, 58.