5 research outputs found
Temperature Compensated Ultrasonic Ranging and Location finder for Blind Person
This paper is intended to provide a theoretical model of object detection and real time assistance via Global Positioning System(GPS).This paper aims at the development of an Electronic Travelling Aid (ETA) kit to help the blind people to find obstacle free path. This ETA is fixed to the stick of the blind people. When the object is detected near to the blinds’ stick it alerts them with the help of vibratory circuit. Ultrasonic sensors are used to evaluate distance of the objects around the blind person to guide the user towards the secure and available path. Output is in the form of vibrations which the blind person can easily recognize. The hardware of entire system contains ARM7 (LPC2138), temperature sensor, ultrasonic sensors and mobile vibrator, Global positioning system (GPS) module and Global System for Mobile (GSM) module. It contains temperature compensation method to reduce the error in measurement of distance using ultrasonic sensors.
DOI: 10.17762/ijritcc2321-8169.15068
Ecology of tubificids in the lower reaches of the Rivers Adige and Brenta (NE Italy)
We studied the tubificid communities of the lower reaches of two Veneto rivers: the Adige and the Brenta.
Our purpose was to investigate whether there is a marked variation in the composition of the family between the stations located upstream in the \u201ctidal-freshwater\u201d zone, and those seaward in the true estuarine zone.
Our data suggest that it is possible to detect a limit between the two zones only for the river Brenta; in fact, in this river the tubificid communities of the three first stations, where the water salinity range is highest, are much poorer then those found in other stretches of the rivers.
Conversely, in the river Adige the tidal-freshwater and the estuarine zones cannot easily be separated: the same tubificid species were found in all stations of the reach examined and the water salinity never exceeds 2.7% also in the seaward station
Atrial bioenergetic variations in moderate hypoxia: danger or protective defense?
The effects of hypoxia on contractile tension and on tissue adenylate pool content, nicotinamide adenine nucleotide, NAD, nicotinamide adenine dinucleotide phosphate, NADP, and creatine phosphate, CrP, were investigated in isolated, spontaneously beating, guinea pig atria. When two different degrees of hypoxia were induced by lowering oxygen tension from 95% O2 (control) to 40% (moderate hypoxia) and 20% (severe hypoxia) for 30 min, contractile tension slowly decreased to 60% and 40% of control, respectively. In 40% O2 hypoxic atria, ATP was not significantly decreased, AMP slightly increased, TAN (total adenylate nucleotides) and adenylate energy charge [(ATP + 0.5 ADP)/(ATP + ADP + AMP)] did not change and creatine phosphate was decreased down to 53%. Hypoxic atria in 20% O2 showed a significant decrease of 26% in ATP, while ADP and AMP increased four and seven times, respectively. The adenylate energy-charge value was reduced from 0.93 to 0.70. Creatine phosphate decreased to below the analytical detection limit. Moderate hypoxia (40% O2), which induced a significant decrease of contractile tension but only minor changes of energetic tissue metabolism, was further investigated 2, 5, and 10 min after low oxygen tension was applied. Two stages of variations were evident during 30 min of experimental hypoxia. Within the first 10 min, concomitantly with atrial tension decrease, ATP, NAD, NADP, ATP/AMP, ATP/ADP, and TAN decreased, CrP began to decrease, inosine and xanthine showed no significant change. During the following 20 min of hypoxia, all parameters returned to the control levels with the exception of creatine phosphate. Adenylate energy charge did not change. The electrophysiological analysis of atrial cells did not show any major change in action potential configuration and resting potential, during 40% O2 hypoxia. The differences at metabolic level between moderate and more severe hypoxia suggest that the energetic state may be extremely unbalanced, in atrial tissue, as long as hypoxia is aggravated. Moreover, the time-course study, during 30 min of 40% O2, suggests that the early decrease of contractile tension does not depend on lowered energy availability, instead it might be, at least in part, a preventive measure to maintain energy balance in myocardial tissue to counteract hypoxic damage and, in this mechanism of defense, creatine phosphate shuttle seems to play a relevant role