223 research outputs found

    Aerosol Extinction Uncertainty Determination for a Laser-Based Detecting System

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    Quantitative measurement of optic and aerosolic property of troposphere may be carried out from lidar system more easily and with low marginal cost than other system (i.e. satellite observation). The aim of this work is to show how extinction coefficient and water vapor concentration in troposphere may be educed from lidar signals at several altitudes and how uncertainty is close to acceptable value. Real data observations will be presented to demostrate uncertainty range on aerosolic extinction coefficient function

    A SOLAR-POWERED WHITE LED-BASED UV-VIS SPECTROPHOTOMETRIC SYSTEM MANAGED BY PC FOR AIR POLLUTION DETECTION IN FARAWAY AND UNFRIENDLY LOCATIONS

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    This research work regards the design and realization of an absorption spectrophotometer based on a LED light source in place of the usually employed Xenon lamp. The advantage of the use of LED technology resides in several factors such as the reducing of the analyte temperature variations and thus noise generation, which occur if a Xenon light source is used, beside of the high luminous efficiency, reliability, operating duration, lower maintenance and a lower power consumption. This last factor allows to supply the entire designed apparatus using a solar panel thus making the system easly portable for use even in places where the electricity network is absent. An optical filtering system was realized in order to detect the analyte absorption for each wavelength range selected by the optical filters. A PC-interfaced PIC-based control unit used to manage the different functionalities required by the spectophotometer was realized and tested. The control unit acquires and processes, via the developed firmware, the raw data provided by different sensors employed in the system. The sensors are used to monitor analyte temperature and humidity values, to control the analyte pressure and to acquire the luminous intensity value of the light beam before and after passing through the analyte. Finally, the realized electronic control unit actuates different mechanical sections (stepper motor, solenoid valve), sincronyzing and controlling the data exchange between hardware sections, microcontroller and the PC

    impedance method for leak detection in zigzag pipelines

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    Transportation of liquids is a primary aspect of human life. The most important infrastructure used accordingly is the pipeline. It serves as an asset for transporting different liquids and strategic goods. The latter are for example: chemical substances, oil, gas and water. Thus, it is necessary to monitor such infrastructures by means of specific tools. Leakage detection methods are used to reveal liquid leaks in pipelines for many applications, namely, waterworks, oil pipelines, industry heat exchangers, etc.. The configuration of pipelines is a key issue because it impacts on the effectiveness of the method to be used and, consequently, on the results to be counterchecked. This research illustrated an improvement of the impedance method for zigzag pipeline by carrying out an experimental frequency analysis that has been compared with other methods based on frequency response. Hence, the impedance method is generally used for simple (straight) pipeline configurations because complicated pipelines with many curves introduce difficulties and major uncertainties in the calculation of characteristic impedance and in the statement of boundary conditions. The paper illustrates the case of a water pipeline where the leakage is acquired thanks to pressure transducers

    MODELING AND DESIGNING A FULL BEAMFORMER FOR ACOUSTIC SENSING AND MEASUREMENT

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    Acoustic sensing is a viable approach for solving issues related to many applications, namely, biomedical, distance measurements, mechanical, health infrastructure monitoring, etc. It is generally sustainable and of no negative impact on the object under test. The use of acoustic sensing under beamforming technique is an important asset to be exploited, especially for the aforementioned applications. This paper illustrates a generalized approach of modeling and designing a full beamfomer using two specific classes: LCMP (Linear Constrained Minimum Power) beamformers that are used to overcome robustness limitations and MVDR (Minimum Variance Distortionless Response) beamformers. Any aspect of modeling and designing is always related to the DOA (Direction of Arrival). The obtained results are based on assumptions extracted from an actual case of constructed system

    A System for Optimizing Fertilizer Dosing in Innovative Smart Fertigation Pipelines: Modeling, Construction, Testing and Control

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    Smart fertigation is a topic of great interest in the effort to optimize different activities involved in local and extensive agriculture for assisting crops, optimizing production by using wireless technologies, data-processing electronic boards and sensors network. With the advent of Agriculture 4.0, similar to Industry 4.0, Information Communication Technology (ICT), associated with mechatronics, is giving an added value to this technique allowing optimization of water, fertilizers, control of water flow in pipes and period of irrigation. This paper intends to illustrate findings related to an innovative low cost system for assisting crops and achieving an accurate farming by investigating on the design, construction, testing and control of dosing system for liquid and granular fertilizers. Four different dosage systems have been designed, realized and tested with different granular and liquid fertilizers; the analysis of an extensive experimental campaign allows to define the characteristic and the mathematical expressions for each analyzed fertilizer and for each dosage system. The accurate modeling allows to control with extreme precision the realized dosing systems after estimating the quantity of fertilizer which the crop needs by means of the smart fertigation system. The obtained results permit the optimization of the fertilizer dosage in terms of quantity, which at the same time translates into lower production costs, greater environmental sustainability and optimization of production in terms of quantity and quality
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