Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 279 )

2018 ( 357 )

2017 ( 374 )

2016 ( 570 )

Custom range...

Search Results: 1 - 10 of 203247 matches for " N. Venkateswara Rao "
All listed articles are free for downloading (OA Articles)
Page 1 /203247
Display every page Item
A remarkable correlation between short period gravity waves and semiannual oscillation of the zonal wind in the equatorial mesopause region
N. Venkateswara Rao, T. Tsuda,Y. Kawatani
Annales Geophysicae (ANGEO) , 2012,
Abstract: The variability of zonal winds and the horizontal wind velocity variance of short period (20–120 min) gravity waves (GWs) in the equatorial mesopause region are studied using medium frequency (MF) radar observations from Pameungpeuk (7.4° S, 107.4° E) during 2004–2010. The zonal winds display a distinct semiannual oscillation (called mesospheric semiannual oscillation, MSAO), with westward winds during equinoxes and eastward winds during solstices. Furthermore, the westward winds during March equinox are larger during 2008 and 2009. The short period GW variance also shows a semiannual oscillation with enhanced activity during equinoxes. A good correlation is observed between the zonal winds and the short period GW variance from 2008–2010, with the winds being westward during the times of enhanced GW activity. Such a correlation, however, is less obvious during 2004–2006. The long period (10–20 h) GW variance, on the other hand, does not show such a correlation throughout the observation period.
Diurnal variation of short-period (20–120 min) gravity waves in the equatorial Mesosphere and Lower Thermosphere and its relation to deep tropical convection
N. Venkateswara Rao, Y. Shibagaki,T. Tsuda
Annales Geophysicae (ANGEO) , 2011,
Abstract: We study short period gravity waves (20–120 min) in the equatorial Mesosphere and Lower Thermosphere (MLT) using a Medium Frequency (MF) radar at Pameungpeuk (7.4° S, 107.4° E), Indonesia. In particular, we study local time and seasonal variation of the gravity wave variance and its relation to tropical convection. The gravity wave variance at 88 km enhances between 20:00 LT and 07:00 LT, with a peak at 02:00–03:00 LT. The enhancement is mainly observed during February–April and September–October and shows inter-annual variability. Convective activity over the same location persists from 16:00–21:00 LT with a peak activity ~18:00 LT and enhances between November–April. Time delay between the peak of convection and that of gravity wave activity ranges 1–15 h, which is consistent with theoretical calculations and previous reports based on reverse ray tracing analysis.
Contribution to 1-quasi-total Graphs
R.V.N. Srinivasa Rao,J. Venkateswara Rao
Asian Journal of Mathematics & Statistics , 2013,
Abstract: This study illustrate some narrative and remarkable properties of 1-quasi-total graphs. It has been acquired results of various graphs such as regular graphs, complete graphs, complete bipartite, cycles and chromatic number of 1-quasi-total graphs.
First simultaneous lidar observations of sodium layers and VHF radar observations of E-region field-aligned irregularities at the low-latitude station Gadanki
S. Sridharan, A. K. Patra, N. Venkateswara Rao,G. Ramkumar
Annales Geophysicae (ANGEO) , 2009,
Abstract: Simultaneous observations of atmospheric sodium (Na) made by a resonance lidar and E-region field-aligned-irregularities (FAI) made by the Indian MST radar, both located at Gadanki (13.5° N, 79.2° E) and horizontal winds acquired by a SKiYMET meteor radar at Trivandrum (8.5° N, 77° E) are used to investigate the relationship among sodium layer, FAI and neutral winds in the mesosphere and lower thermosphere region. The altitudes and descent rates of higher altitude (~95 km) Na layer and FAI agree quite well. The descending structures of the higher altitude Na layer and FAI are found to be closely related to the diurnal tidal phase structure in zonal winds observed over Trivandrum. At lower altitudes, the descent rate of FAI is larger than that of Na layer and zonal tidal phase. These observations support the hypothesis that the metallic ion layers are formed by the zonal wind shear associated with tidal winds and subsequently get neutralized to manifest in the form of descending Na layers. The descending FAI echoing layers are manifestation of the instabilities setting in on the ionization layer. In the present observations, the altitudes of occurrence of Na layer and FAI echoes being low, we surmise that it is quite possible that the FAI echoes are due to the descent of already formed irregularities at higher altitudes.
A Critical Review on Microtools Fabrication by Focused Ion Beam (FIB) Technology
Sanket N. Bhavsar,S. Aravindan,P. Venkateswara Rao
Lecture Notes in Engineering and Computer Science , 2009,
Trends in Cardiac Pacemaker Batteries
Venkateswara Sarma Mallela,V. Ilankumaran,N.Srinivasa Rao
Indian Pacing and Electrophysiology Journal , 2004,
Abstract: Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future.
RP-HPLC Method for the Estimation of Nelfinavir Mesylate in Tablet Dosage Form
K. Vanitha Prakash,J. Venkateswara Rao,N. Appala Raju
Journal of Chemistry , 2007, DOI: 10.1155/2007/654706
A Validated RP-HPLC Method for the Determination of Atazanavir in Pharmaceutical Dosage Form
K. Srinivasu,J. Venkateswara Rao,N. Appala Raju,K. Mukkanti
Journal of Chemistry , 2011, DOI: 10.1155/2011/812879
Morbidly obese parturient: Challenges for the anaesthesiologist, including managing the difficult airway in obstetrics. What is new?
Rao Durga,Rao Venkateswara
Indian Journal of Anaesthesia , 2010,
Abstract: The purpose of this article is to review the fundamental aspects of obesity, pregnancy and a combination of both. The scientific aim is to understand the physiological changes, pathological clinical presentations and application of technical skills and pharmacological knowledge on this unique clinical condition. The goal of this presentation is to define the difficult airway, highlight the main reasons for difficult or failed intubation and propose a practical approach to management Throughout the review, an important component is the necessity for team work between the anaesthesiologist and the obstetrician. Certain protocols are recommended to meet the anaesthetic challenges and finally concluding with "what is new?" in obstetric anaesthesia.
An Increased Risk of Osteoporosis during Acquired Immunodeficiency Syndrome
Annapoorna N.,Rao G.Venkateswara,Reddy N.S.,Rambabu P.
International Journal of Medical Sciences , 2004,
Abstract: Osteoporosis is characterized by decreased bone mineral density and mechanistic imbalances of bone tissue that may result in reduced skeletal strength and an enhanced susceptibility to fractures. Osteoporosis in its most common form affects the elderly (both sexes) and all racial groups of human beings. Multiple environmental risk factors like acquired immune deficiency syndrome (AIDS) are believed to be one of the causes of osteoporosis. Recently a high incidence of osteoporosis has been observed in human immunodeficiency virus (HIV) infected individuals. The etiology of this occurrence in HIV infections is controversial. This problem seems to be more frequent in patients receiving potent antiretroviral therapy. In AIDS, the main suggested risk factors for the development of osteoporosis are use of protease inhibitors, longer duration of HIV infection, lower body weight before antiretroviral therapy, high viral load. Variations in serum parameters like osteocalcin, c-telopeptide, levels of elements like Calcium, Magnesium, Phosphorus, concentration of vitamin-D metabolites, lactate levels, bicarbonate concentrations, amount of alkaline phosphatase are demonstrated in the course of development of osteoporosis. OPG/RANKL/RANK system is final mediator of bone remodeling. Bone mineral density (BMD) test is of added value to assess the risk of osteoporosis in patients infected with AIDS. The biochemical markers also aid in this assessment. Clinical management mostly follows the lines of treatment of osteoporosis and osteopenia.
Page 1 /203247
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.