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Search Results: 1 - 10 of 68 matches for " RANGASWAMY MUNIAPPAN "
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Cycad Aulacaspis Scale, a Newly Introduced Insect Pest in Indonesia
RANGASWAMY MUNIAPPAN,GILLIAN W. WATSON,GREGORY ALLYN EVANS,AUNU RAUF
HAYATI Journal of Biosciences , 2012,
Abstract: Cycad aulacaspis scale (Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae)) is native to Thailand and Vietnam. Since the early 1990s it has been spreading around the world due to the trade in cycad plants for ornamental use. Infestation by this scale can kill cycads in only a few months. Its accidental introduction to Florida endangered the ornamental cycad-growing industry; and in Guam and Taiwan, endemic cycads (Cycas micronesica and C. taitungensis, respectively) are currently threatened with extinction by cycad aulacaspis scale. In November 2011, an introduced scale was discovered damaging cycads in the Bogor Botanic Garden. Samples from Bogor were taken for identification of the scale, and the material was kept for some time to rear out any insect parasitoids that were present. Both the scale insects and parasitoids were prepared on microscope slides and studied microscopically for authoritative identification. The scale was confirmed as A. yasumatsui. The parasitoid Arrhenophagus chionaspidis Aurivillius (Hymenoptera: Encyrtidae) and the hyperparasitoid Signiphora bifasciata Ashmead (Hymenoptera: Signiphoridae) were identified from the samples. Unless immediate remedial measures are taken, several endemic species of cycad in Indonesia may be endangered by infestation by cycad aulacaspis scale.
Development of Compact Ultra-Wideband (UWB) Microstrip Bandpass Filter  [PDF]
Kaliyavarathan Thirumalaivasan, Rangaswamy Nakkeeran
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2011, DOI: 10.4236/jemaa.2011.38053
Abstract: Miniaturized Ultra-Wideband (UWB) microstrip bandpass filter with wide passband is presented. The filter is developed based on modified multiple mode resonator, which is formed by transversely attaching three pairs of non-uniform and folded stubs with lowpass and highpass sections. Both sides of high-impedance section are linked with two feed lines via direct coupled lines, resulting UWB bandpass filter. The designed filter provides 7 GHz passband between 2.5 and 9.5 GHz with approximately, –0.5 dB insertion loss, –35 dB minimum return loss at 6.85 GHz, linear phase over the passband and 110% of fractional bandwidth at –3 dB. The computed group delay variation in the passband for the filter is 0.02 ns. The overall dimension of the filter is 10.7 mm (length) × 3 mm (width) × 1.6 mm (thickness).
Development of Hexagonal MMR Based UWB Bandpass Filter with 5 GHz Notch Band  [PDF]
Kaliyavarathan Thirumalaivasan, Rangaswamy Nakkeeran
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2011, DOI: 10.4236/jemaa.2011.38054
Abstract: This paper presents an experimental verification of ultra-wideband bandpass filter (BPF) for UWB applications and notch filter in order to suppress 5 GHz narrowband service when it coexists with UWB radio system. The BPF consists of a hexagonal shaped multiple mode resonator (MMR) with interdigital coupling at both sides. Notch filter is derived from BPF by introducing four embedded open stubs near by the MMR. The developed BPF has insertion loss of –2 dB and the minimum return loss about –35 dB, while for the notch filter they are –3 dB and –40 dB respectively. The group delay obtained for bandpass filter is below 0.2 ns and for notch filter, it is about 0.3 ns. With the above structural features the overall dimensions of the filter is 38 mm (length) × 3.2 mm (breadth) × 1.6 mm (height) and the percentage fractional bandwidth (FBW) of the proposed filter is about 120.48%.
Performance Analysis of Unified Failure Model for Emerging WiMAX Networks  [PDF]
Rajesh Anbazhagan, Nakkeeran Rangaswamy
Wireless Engineering and Technology (WET) , 2012, DOI: 10.4236/wet.2012.32011
Abstract: In this paper, we present a failure model for WiMAX network developed by considering the collision due to contention, unavailability of bandwidth and channel error assuming them as independent events. Using this model, the performance of bandwidth request based on contention resolution with exponential increase and exponential decrease (EIED) backoff is investigated and observed low contention efficiency with high access delay. Hence, we modify the EIED mechanism by computing the backoff factor with average contention window and estimating the response time from the transmission failure. Simulations validate the developed model with modified EIED backoff and shows better performance than conventional scheme.
Strength Characterization of E-glass Fiber Reinforced Epoxy Composites with Filler Materials  [PDF]
K. Devendra, T. Rangaswamy
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2013, DOI: 10.4236/jmmce.2013.16054
Abstract: In this research work, an investigation was made on the mechanical properties of E-glass fiber reinforced epoxy composites filled by various filler materials. Composites filled with varying concentrations of fly ash, aluminum oxide (Al2O3), magnesium hydroxide (Mg(OH)2) and hematite powder were fabricated by standard method and the mechanical properties such as ultimate tensile strength, impact strength and hardness of the fabricated composites were studied. The test results show that composites filled by 10% volume Mg(OH)2 exhibited maximum ultimate tensile strength and hardness. Fly ash filled composites exhibited maximum impact strength.
A Comparative Study on Dry Sliding Wear Characteristics of Al2O3 and Bone Powder Filled Hybrid Composites  [PDF]
Sudeep Deshpande, T. Rangaswamy
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2016, DOI: 10.4236/jmmce.2016.42016
Abstract: The aim of the research was to develop E-glass/jute fiber reinforced epoxy composites with an addition of Al2O3 and bone powder by using hand layup technique and to compare tribological properties of these composites under similar test conditions. The wear experiments were designed according to Taguchi’s (L27) orthogonal array with three control variables such as sliding velocity, filler content and normal load. The results indicated that the normal load for Al2O3 and filler content for bone powder emerged as the significant factors affecting specific wear rate of hybrid composites. An addition of 10 wt% of bone powder or Al2O3 into E-glass/jute fiber reinforced epoxy composites increased the wear resistance considerably, and natural waste bone powder can be used instead of ceramic filler Al2O3 in hybrid composites. After the analysis of control factors, an optimal factor setting has been suggested for specific wear rate and coefficient of friction. Further, the scanning electron microscopy (SEM) images for worn surfaces of hybrid composites were studied. Finally, a confirmation test was carried out to validate the results.
Induction of insulin secretion in engineered liver cells by nitric oxide
Latha Muniappan, Sabire ?zcan
BMC Physiology , 2007, DOI: 10.1186/1472-6793-7-11
Abstract: Expression of either human insulin or the beta cell specific transcription factors PDX-1, NeuroD1 and MafA in the Hepa1-6 cell line or primary liver cells via adenoviral gene transfer, results in production and secretion of insulin. Although, the secretion of insulin is not significantly increased in response to high glucose, treatment of these engineered liver cells with L-arginine stimulates insulin secretion up to three-fold. This L-arginine-mediated insulin release is dependent on the production of nitric oxide.Liver cells can be engineered to produce insulin and insulin secretion can be induced by treatment with L-arginine via the production of nitric oxide.Insulin is essential in maintaining normal blood glucose levels and is produced and secreted by the beta cells of pancreas in response to increased blood glucose levels. Defects in insulin production and secretion, as observed in type 1 diabetes due to autoimmune destruction of the pancreatic beta cells, result in chronic hyperglycemia, which is responsible for most of the secondary complications associated with diabetes. Besides insulin injections, the only other option for treatment of type 1 diabetes is islet transplantation. Because of the lack of insulin production, gene therapy using surrogate beta cells is a potential approach in the treatment of Type 1 diabetes [1-3]. Delivery of insulin by gene therapy represents an attractive alternative to protein replacement therapy by potentially providing a more convenient and cost-effective delivery strategy.Successful therapy for Type 1 diabetes requires that mature insulin be produced and secreted from surrogate beta-cells in a glucose-regulated manner. Liver appears to be an excellent surrogate organ for production of insulin, because it contains a glucose sensing machinery that is similar to pancreatic beta cells [4-7]. Liver and pancreatic beta cells both express GLUT-2 and glucokinase [7,8]. Moreover, viral gene transfer into hepatocytes is very efficien
Protective role of Scoparia dulcis plant extract on brain antioxidant status and lipidperoxidation in STZ diabetic male Wistar rats
Leelavinothan Pari, Muniappan Latha
BMC Complementary and Alternative Medicine , 2004, DOI: 10.1186/1472-6882-4-16
Abstract: Aqueous extract of Scoparia dulcis plant was administered orally (200 mg/kg body weight) and the effect of extract on blood glucose, plasma insulin and the levels of thiobarbituric acid reactive substances (TBARS), hydroperoxides, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) were estimated in streptozotocin (STZ) induced diabetic rats. Glibenclamide was used as standard reference drug.A significant increase in the activities of plasma insulin, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and reduced glutathione was observed in brain on treatment with 200 mg/kg body weight of Scoparia dulcis plant extract (SPEt) and glibenclamide for 6 weeks. Both the treated groups showed significant decrease in TBARS and hydroperoxides formation in brain, suggesting its role in protection against lipidperoxidation induced membrane damage.Since the study of induction of the antioxidant enzymes is considered to be a reliable marker for evaluating the antiperoxidative efficacy of the medicinal plant, these findings suggest a possible antiperoxidative role for Scoparia dulcis plant extract. Hence, in addition to antidiabetic effect, Scoparia dulcis possess antioxidant potential that may be used for therapeutic purposes.The neurological consequences of diabetes mellitus in the Central Nervous System (CNS) are now receiving greater attention. Cognitive deficits, along with morphological and neurochemical alterations illustrate that the neurological complications of diabetes are not limited to peripheral neuropathies [1]. The central complications of hyperglycemia also include the potentiation of neuronal damage observed following hypoxic/ischemic events, as well as stroke [2]. Glucose utilization is decreased in the brain during diabetes [2], providing a potential mechanism for increased vulnerability to acute pathological events.Oxidative stress, leading to an
Lipoabdominoplasty: A versatile and safe technique for abdominal contouring
Rangaswamy Mohan
Indian Journal of Plastic Surgery , 2008,
Abstract:
Minimization of Collision in Energy Constrained Wireless Sensor Network  [PDF]
Moses Nesa SUDHA, Muniappan Lakshapalam VALARMATHI, George RAJSEKAR, Michael Kurien MATHEW, Nagarajan DINESHRAJ, Sivasankaran RAJBARATH
Wireless Sensor Network (WSN) , 2009, DOI: 10.4236/wsn.2009.14043
Abstract: Wireless Sensor Networks (WSNs) are one of the fastest growing and emerging technologies in the field of Wireless Networking today. The applications of WSNs are extensively spread over areas like Military, En-vironment, Health Care, Communication and many more. These networks are powered by batteries and hence energy optimization is a major concern. One of the factors that reduce the energy efficiency of the WSN is collision which occurs due to the high density of data packets in a typical communication channel. This paper aims at minimizing the effects of congestion leading to collision in the network by proposing an effective algorithm. This can be done by optimizing the size of the contention window by introducing pa-rameters like source count and α. If the contention window of a node is low, it results in collision. If the size of the contention window of a node is high then it results in a medium access delay. Thus minimizing colli-sion and medium access delay of data packets conserve energy.
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