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Search Results: 1 - 10 of 325332 matches for " Shivakumar S "
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Statistical optimization for improved indole-3-acetic acid (iaa) production by Pseudomonas aeruginosa and demonstration of enhanced plant growth promotion
Sasirekha,B; Shivakumar,S;
Journal of soil science and plant nutrition , 2012, DOI: 10.4067/S0718-95162012005000038
Abstract: the present study was undertaken to study the statistical optimization of medium components for improved indole-3- acetic acid (iaa) production by pseudomonas aeruginosa. colorimetric analysis showed maximum iaa (132 ìg ml-1) in the medium supplemented with tryptophan (0.5 g l-1). the maximum production was achieved after 96 h of incubation. yeast extract, tryptophan and edta were identified as significant components influencing iaa production by pseudomonas aeruginosa, using the plackett- burman method. the statistical optimization approach led to the production of 318 ìg ml-1 of iaa within 24 h of incubation. statistical approach was found to be very effective in optimizing the medium components in a manageable number of experimental runs with overall 2.4 fold increase in iaa production. tlc and gc- ms analysis further confirmed the iaa production in the cell filtrates of the strain. gc-ms analysis and tryptophan side chain oxidase confirmed the existence of atleast 2 possible pathways for iaa by this strain. inoculation of p. aeruginosa culture filtrate enhanced seed germination (82.4%) and increase in root length and shoot length (~ 2.6 and ~ 1.1 folds over the control) of cowpea seeds over the control treatment under pot culture conditions.
Statistical optimization for improved indole-3-acetic acid (iaa) production by Pseudomonas aeruginosa and demonstration of enhanced plant growth promotion
B Sasirekha,S Shivakumar
Journal of Soil Science and Plant Nutrition , 2012,
Abstract: The present study was undertaken to study the statistical optimization of medium components for improved Indole-3- acetic acid (IAA) production by Pseudomonas aeruginosa. Colorimetric analysis showed maximum IAA (132 ìg mL-1) in the medium supplemented with tryptophan (0.5 g L-1). The maximum production was achieved after 96 h of incubation. Yeast extract, tryptophan and EDTA were identified as significant components influencing IAA production by Pseudomonas aeruginosa, using the Plackett- Burman method. The statistical optimization approach led to the production of 318 ìg mL-1 of IAA within 24 h of incubation. Statistical approach was found to be very effective in optimizing the medium components in a manageable number of experimental runs with overall 2.4 fold increase in IAA production. TLC and GC- MS analysis further confirmed the IAA production in the cell filtrates of the strain. GC-MS analysis and tryptophan side chain oxidase confirmed the existence of atleast 2 possible pathways for IAA by this strain. Inoculation of P. aeruginosa culture filtrate enhanced seed germination (82.4%) and increase in root length and shoot length (~ 2.6 and ~ 1.1 folds over the control) of cowpea seeds over the control treatment under pot culture conditions.
Real-Time Sensor-Actuator Networks
Shivakumar Sastry,S. S. Iyengar
International Journal of Distributed Sensor Networks , 2005, DOI: 10.1080/15501320490886314
Abstract: Emerging technologies offer new paradigms for computation, control, collaboration, and communication. To realize the full potential of these technologies in industry, defense, and homeland security applications, it is necessary to exploit the real-time distributed computing capabilities of sensor-actuator networks. To reliably design and develop such networks, it is necessary to develop deeper insight into the underlying model for real-time computation and the infrastructure at the node level that supports this model. In this paper, we discuss a new node-level operating system and mechanisms necessary to deploy reliable applications. The overriding issue that guides the design of this operating system is quality of service metric called predictability.
LITERATURE REVIEW OF FIBER REINFORCED POLYMER COMPOSITES
Shivakumar S,G. S. Guggari
International Journal of Advances in Engineering and Technology , 2011,
Abstract: Polymer-matrix composites (PMCs) have been used for a variety of structural memberships for chemical plants and airplanes, since they have outstanding performances, such as lightweight and good fatigue properties. To hold the long-term durability and to estimate the residual life of the composites under some hostile environments, it is an important issue to clarify the facture and/or the failure mechanism in each service conditions. Degradation of components made from polymeric materials occurs in a wide variety of environments and service conditions, and very often limits the service lifetime. Degradation occurs as the result of environment-dependent chemical or physical attack, often caused by a combination of degradation agents, and may involve several chemical and mechanical mechanisms. The main concern of this review will be to examine the causes of degradation of polymeric components from the completion of fabrication to ultimate failure.
DEATH ANXIETY AND PSYCHOLOGICAL WELL-BEING OF HIV POSITIVE PATIENTS AND HIV TB CO-INFECTED PATIENTS
VANISRI,SHIVAKUMAR S.CHENGTI
Golden Research Thoughts , 2012, DOI: 10.9780/22315063
Abstract: The main purpose of the study is to investigate the Death Anxiety and Psychological Well-being of HIV +ve patients and HIV TB co-infected patients and the examine the difference between gender and type of disease of the study on their death anxiety and psychological well-being. For this investigation sample consists of 80, (40 HIV +ve and 40 HIV TB co-infected) were taken from Gulbarga District, Karnataka State. This sample consists of both male and female HIV +ve patients and HIV TB coinfected male and female samples. Death anxiety scale and psychological well-being scale was used for this study, and't' test was applied to examine the difference between sample subgroups. The result through the study showed significant difference between male and female HIV +ve patients and HIV TB co-infected patients in death anxiety and psychological well-being.
Fracture Toughness of Glass-Carbon (0/90)s Fiber Reinforced Polymer Composite – An Experimental and Numerical Study  [PDF]
P.S. Shivakumar Gouda, S.K. Kudari, S. Prabhuswamy, Dayananda Jawali
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2011, DOI: 10.4236/jmmce.2011.108052
Abstract: Mode-I fracture behavior of glass-carbon fiber reinforced hybrid polymer composite was investigated based on experimental and finite element analysis. The compact tension (CT) specimen was employed to conduct mode-I fracture test using special loading fixtures as per ASTM standards. Fracture toughness was determined experimentally for along and across the fiber orientation of the specimen. Results indicated that the cracked specimens are tougher along the fiber orientations as compared with across the fiber orientations. A similar fracture test was simulated using finite element analysis software ANSYS. Critical stress intensity factor (K) was calculated at fracture/failure using displacement extrapolation method, for both along and across the fiber orientations. The fractured surfaces of the glasscarbon epoxy composite under mode-I loading condition was examined by electron microscope.
Corrosion Behavior and Adsorption Thermodynamics of Some Schiff Bases on Mild Steel Corrosion in Industrial Water Medium
S. S. Shivakumar,K. N. Mohana
International Journal of Corrosion , 2013, DOI: 10.1155/2013/543204
Abstract: The inhibition performance and adsorption behavior of (E)-2-(3-nitrobenzylidene) hydrazine carbothioamide (SB1) and (E)-2-(4-(dimethylamino) benzylidene) hydrazine carbothioamide (SB2) on mild steel corrosion in industrial water medium have been investigated by gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results revealed that inhibition efficiency depends on both the concentration of the inhibitors and temperature of the system. Increasing temperature reduces the inhibition efficiency of both inhibitors. Polarization studies indicated that these compounds behave as mixed type of inhibitors. The adsorption of both inhibitors was spontaneous and followed Langmuir adsorption isotherm. Thermodynamic parameters are calculated and discussed. The relation between inhibition efficiency and molecular structures of SB1 and SB2 was discussed by considering quantum chemical parameters. The surface adsorbed film was characterized by scanning electron microscopy (SEM). 1. Introduction Mild steel (MS) is the widely used material in the fabrication of heating and cooling water system in many industries. Therefore, study of corrosion inhibition of mild steel in industrial water medium is a subject of technological importance. Organic compounds which are extensively used in several industries as corrosion inhibitors in various environments [1–3]. The anticorrosive property of these inhibitors depends on the specific interaction between certain functional groups in the inhibitors with the active centers on the metal surface [4–7]. Hetero atoms such as nitrogen, oxygen, and sulphur present in the inhibitors play an important role in this interaction by donating lone pair of electrons [8–12]. Hence the organic compounds containing these hetero atoms and multiple bonds behave as efficient corrosion inhibitors due to the availability of π-electrons for interaction with the metal surface [13]. The compounds containing an azo methine group (–C=N–) in their skeleton (Schiff bases) are the best examples for this type of corrosion inhibitors. They can be synthesized by condensation of primary amines with carbonyl compounds [14]. Schiff bases were reported as effective corrosion inhibitors for mild steel, copper, and aluminum in various media [15–24]. Although most of the commercial corrosion inhibitors are synthesized by using aldehydes and amines as main components, usually these Schiff bases possess more inhibition efficiency than their constituent carbonyls and amines [25, 26]. The higher inhibition efficiencies of
Bioadhesive Controlled Release Clotrimazole Vaginal Tablets
S Bhat, H.G Shivakumar
Tropical Journal of Pharmaceutical Research , 2010,
Abstract: Purpose: To formulate bioadhesive clotrimazole vaginal tablets using natural polymers in order to provide long-term therapeutic action at the site of infection. Methods: The tablets were prepared by direct compression using bioadhesive polymer mixtures: hydroxypropyl methylcellulose/sodium carboxymethylcellulose (HPMC/NaCMC) and HPMC/Guar gum (GG) in different ratios. Differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopic evaluations were carried out to assess compatibility between the drug and the excipients. The tablets were subjected to various pre- and post-compression evaluations, including in vitro drug release, in vitro bioadhesive strength, swelling and stability studies. Results: The results show that all the formulations satisfied Indian Pharmacopoeial specifications for tablet parameters. DSC and FT-IR data indicate there was no interaction between the drug and the excipients. Drug dissolution rate at pH 6.0 followed the rank order: HPMC)/NaCMC > HPMC/GG. There was increase in swelling index with time at 37 0C. The combination of HPMC with NaCMC showed greater mucoadhesive strength and superior controlled drug release to the formulations prepared with GG polymer mixture. Furthermore, the release properties of the former in pH 6.0 buffer, as well as release mechanism (n values), were negligibly affected by ageing. Conclusion: This study indicates the possible use of suitable mixtures of natural and semi-synthetic cellulosic polymers for the preparation of clotrimazole mucoadhesive tablets for application as a vaginal controlled delivery system.
EMOTIONAL INTELLIGENCE AND MENTAL HEALTH IN ADOLESCENTS
MALLIKARJUN H.KRISHNAKAR,SHIVAKUMAR S. CHENGTI
Golden Research Thoughts , 2012, DOI: 10.9780/22315063
Abstract: The major aim of the present study was to assess the Emotional intelligence and mental health in adolescents. The sample of 100 (50 Boys and 50 Girls) students was chosen from Gulbarga district on whom the Emotional intelligence and Mental Health Scales were administered. After scoring, the data were subjected to t – test. The results revealed that there is significant difference in Mental Health of the sample subgroups. The study also revealed significant gender differences in the amount of mental health.
Power System Stability Enhancement by Neuro Fuzzy Logic Based SVC for Multi Machine System
S. Sabna,,D. Prasad,,R. Shivakumar
International Journal of Engineering and Advanced Technology , 2012,
Abstract: This paper presents a hybrid technique to small signal stability enhancement using ANFIS thruster susceptance control of static vary compensator (SVC). Their main objective is to determine the synchronous generator’s ability to maintain stability after the occurrence of a fault or following a major change in the network such as the loss of an important generator or a large load. Static vary compensator is proven the fact that it improves the dynamic stability of power system apart from reactive power compensation; it has multiple role in the operation of power system. The main variable to be controlled in the power system for efficient operation is to mitigating the rotor electro-mechanical low frequency oscillations. Simulations are carried out for multi machine power system for without SVC and with ANFIS SVC. The proposed Neuro fuzzy logic based SVC for multi machine power system provides better damping to power system oscillation.
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