Assessment of GPS radiosonde descent data

Radiosondes are widely used to obtain basic meteorological parameters such as pressure (<i>P</i>), temperature (<i>T</i>), relative humidity (RH) and horizontal winds during the balloon ascent up to the altitude of balloon burst, usually ~ 32–35 km. Data from the radiosondes released from Gadanki (13.5° N, 79.2° E), a tropical station in India, have been collected during the ascent and during the descent as well without attaching any parachute or its equivalent since the year 2008. In the present study an attempt has been made to characterize the radiosonde descent data with the main objective of exploring its usefulness and reliability for scientific purposes. We compared the data obtained during ascent and descent phases of the same sounding. The mean differences in <i>T</i>, RH and horizontal winds between ascent and descent data are found to be small and are sometimes even within the uncertainty of the measurements and/or expected diurnal variation itself. The very good consistency observed between the ascent and the descent data shows that one more profile of the meteorological parameters can be constructed within 3 h of time of balloon launch practically at no additional cost. Further checks are done by utilizing the 3-hourly radiosonde observations collected during the Tropical Tropopause Dynamics campaigns conducted at Gadanki. In the process of checking the consistency between the radiosonde ascent and descent data, several new findings are arrived at and are reported in this study. In general, it has taken more than half an hour for the balloon to reach the ground from the burst altitude. It is also observed that the fall velocity is close to 10 m s⁻¹ near the surface. Finally, it is suggested to record the observations also when the balloon is descending as this information is useful for scientific purposes

Ortho Linear Feedback Shift Register Cryptographic System

In this article, an encryption algorithm with an error detection technique is presented for highly secured reliable data transmission over unreliable communication channels. In this algorithm, an input data is mapped into orthogonal code first. After that the code is encrypted with the help of Linear Feedback Shift Register (LFSR). The technique has been successfully verified and synthesized using Xilinx by Spartan-3E FPGA. The results show that the error detection rate has been increased to 100% by proposed encryption scheme is effective and improves bandwidth efficiency

New Control Strategy of Interconnected Micro grids for Enhancing Power Sharing Capability

In this paper, Due to some operational barriers to existing power management systems the AC-DC connected grids are only involved in power sharing or power control but not in both, in order to overcome these problems this paper is proposed. This proposed autonomous power control system will look at the specific state of the DC grid loading before importing power from a interlinked AC micro grid. This strategy not only converts power to a DC micro grid but also reduces the number of active converters that will reduce energy transfer losses. The proposed system is completely self-contained as it adheres to the plug-n-play features of generators and tie-converters. The effectiveness of the proposed control system is guaranteed under various operating conditions. The results reveal the usefulness of the proposed system for managing DC micro grid power shortages efficiently autonomously, while maintaining better power control and voltage regulations over the DC Micro grid. Results are verified by MATLAB / SIMULINK environment

Implementing And Comparison of MANET Routing Protocols Using NS2

Abstract — In the past few years we have seen a hasty inflation in the terrain of mobile computing. Due to upturn of inexpensive, widely available wireless devices, Ad-hoc networks has now become one of the most vibrant and active field of communication and networks. A Mobile Ad-hoc Network (MANET) is a self articulation wireless Ad-hoc network of mobile nodes. Each node has a router or a switch connected by wireless connection. A MANET depends upon the location of nodes, their connectivity, their service discovery capability, and ability to search and route messages using the nearest nodes.We have used NS2 simulator from scalable networks to perform the simulations. NS2 is a discrete event driven packet level network simulator. it support for TCP, routing and multicast protocols over wired and wireless network. This paper provides insight into ad hoc routing protocols (DSDV, AOMDV) and their metrics (Throughput, end to end delay, Packet loss) using NS2

Impedance based service life assessment of corroded structures with Cross correlation analysis

Electro mechanical impedance technique has garnered major significance in structural health monitoring field by integrating with information and sensing technology. Technical advancements in automated smart devices improved the diagnostic evaluation of this monitoring method by incorporating piezoelectric materials. The optimistic coupling property of these materials enhanced the life span of structural members by detecting damages at incipient stage. The intervention of piezoelectric transducers has created potential applications for impedance approach in assessing the structural performance with high feasibility. The present work aims at estimating the service life of simply supported smart beam using piezoelectric sensors in Abaqus Simulia software. Corrosion is deployed at a uniform rate in reinforced concrete beam with impressed current flow and the loss in diameter of rebar is calculated using Faraday’s electrochemical equation. With frequency domain based impedance technique numerical analysis is conducted on the modeled beams by exciting the sensor with an external harmonic force and the output electric responses of different piezoelectric locations are captured. The steady state dynamic responses for different cases are compared and quantified with a statistical damage algorithm in MATLAB. The resulted cross correlation indices are analyzed to prevent further deterioration of the corroded beams by setting a limit value. The proposed simulation technology is capable of estimating the residual life span of damage structures with cross correlation analysis

Corrosion assessment of structural components using electro mechanical impedance

Rapid innovation in interdisciplinary technology emphasized the data acquisition system to evaluate the structural integrity by combining with advance sensing techniques. These smart sensors with impedance methodology has shown an excellent potential in assessing the structural health condition and provided an alternative to many sophisticated Non destructive monitoring systems. The sensitivity of electro mechanical impedance technique in detecting local incipient damages is enhanced with piezoelectric mechanism of lead zirconate titanate materials and with conductance signatures these materials can determine the dynamic variations in structural properties more effectively. In the present work numerical finite element analysis is conducted on simply supported RCC beam in Abaqus software with reinforcement subjected to corrosion in five stages with different reduction rates and coupled with piezoelectric transducers along the length to implement the impedance strategy. These surface bonded piezoelectric patches are electrically excited with an external voltage under specific frequency range to conduct linear perturbation harmonic analysis and the output conductance responses of healthy and corroded beams from different sensor locations are captured and compared. The peak shifting nature of signature pattern will serve as an indicator to diagnose the corrosion severity and propagation in structural components. The simulation results of proposed impedance technique showed the feasibility of employing piezoelectric materials to identify corrosion activity in structural members with electromechanical conductivity signatures

Lack of Overt Retinal Degeneration in a K42E Dhdds Knock-In Mouse Model of RP59

Dehydrodolichyl diphosphate synthase (DHDDS) is required for protein N-glycosylation in eukaryotic cells. A K42E point mutation in the DHDDS gene causes an autosomal recessive form of retinitis pigmentosa (RP59), which has been classified as a congenital disease of glycosylation (CDG). We generated K42E Dhdds knock-in mice as a potential model for RP59. Mice heterozygous for the Dhdds K42E mutation were generated using CRISPR/Cas9 technology and crossed to generate DhddsK42E/K42E homozygous mice. Spectral domain-optical coherence tomography (SD-OCT) was performed to assess retinal structure, relative to age-matched wild type (WT) controls. Immunohistochemistry against glial fibrillary acidic protein (GFAP) and opsin (1D4 epitope) was performed on retinal frozen sections to monitor gliosis and opsin localization, respectively, while lectin cytochemistry, plus and minus PNGase-F treatment, was performed to assess protein glycosylation status. Retinas of DhddsK42E/K42E mice exhibited grossly normal histological organization from 1 to 12 months of age. Anti-GFAP immunoreactivity was markedly increased in DhddsK42E/K42E mice, relative to controls. However, opsin immunolocalization, ConA labeling and PNGase-F sensitivity were comparable in mutant and control retinas. Hence, retinas of DhddsK42E/K42E mice exhibited no overt signs of degeneration, yet were markedly gliotic, but without evidence of compromised protein N-glycosylation. These results challenge the notion of RP59 as a DHDDS loss-of-function CDG and highlight the need to investigate unexplored RP59 disease mechanisms