scholarly journals Set up and application of an underwater Α-ray spectrometer for radioactivity measurements

2005 ◽  
Vol 6 (1) ◽  
pp. 35 ◽  
Author(s):  
C. TSABARIS ◽  
S. VLACHOS ◽  
C.T. PAPADOPOULOS ◽  
R. VLASTOU ◽  
C.A. KALFAS
Keyword(s):  
Marine Environment ◽  
Detection System ◽  
On Line ◽  
Parallel Measurement ◽  
Set Up ◽  
And Control ◽  
Potassium 40 ◽  
Radioactivity Measurements ◽  
Term Monitoring

The set up and control of an underwater measuring instrument for radioactivity pollution in the marine environment is described. The detection system is based on a NaI scintillator (RADAM III) with modifications for use in the marine environment with on-line measurements. The system is simple, has low power consumption and is stable for long-term monitoring (10 months). Before its deployment, the sensor was calibrated in the laboratory in a tank full of water to reproduce the marine environment. The calibrations were performed, by detecting the 661keV and 1461 keV gamma rays of known activity liquid sources 137 Cs and 40 K, respectively. The measured spectra in the laboratory were compared with spectra from a similar detector as acquired in the field. The analysis of the parallel measurement gave satisfactory agreement for the concentration of the potassium (40 K), as calculated from the salinity in the seawater, thus enabling the system for quantitative measurement of the seawater radioactivity.

scholarly journals An underwater sensing system for monitoring radioactivity in the marine environment

2004 ◽  
Vol 5 (1) ◽  
pp. 125 ◽  
Author(s):  
C. TSABARIS ◽  
I. THANOS
Keyword(s):  
Marine Environment ◽  
Background Radiation ◽  
Energy Calibration ◽  
Water Tank ◽  
Sensing System ◽  
Set Up ◽  
The Stability ◽  
Term Monitoring ◽  
Time Acquisition

We describe a set up and an application for an autonomously working, radioactivity sensing instrument, usable in seawater and river environments. The system is based on a N aI scintillator with the appropriate specifications for use in the marine environment and for real time acquisition. It is simple, stable for long - term monitoring, and of low consumption. Many tests were carried out for the linearity and the stability of the electronics. The investigation of energy resolution and energy calibration of the sensor was performed in the laboratory using various reference point radioactive sources. The system was also deployed in a water tank in order to measure background radiation in the water and low volumetric activity of 137Cs (17 Bq/m3). Appropriate software identifies qualitatively the low level137Cs contribution to the measured γ-ray spectrum.

scholarly journals Long-term monitoring programme of the hydrological variability in the Mediterranean Sea: a first overview of the HYDROCHANGES network

Ocean Science ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. 301-324 ◽  
Author(s):  
K. Schroeder ◽  
C. Millot ◽  
L. Bengara ◽  
S. Ben Ismail ◽  
M. Bensi ◽  
...  
Keyword(s):  
Time Series ◽  
Mediterranean Sea ◽  
Sampling Interval ◽  
Global Changes ◽  
Hydrological Variability ◽  
Long Term Monitoring ◽  
The Mediterranean ◽  
Set Up ◽  
Term Monitoring

Abstract. The long-term monitoring of basic hydrological parameters (temperature and salinity), collected as time series with adequate temporal resolution (i.e. with a sampling interval allowing the resolution of all important timescales) in key places of the Mediterranean Sea (straits and channels, zones of dense water formation, deep parts of the basins), constitute a priority in the context of global changes. This led CIESM (The Mediterranean Science Commission) to support, since 2002, the HYDROCHANGES programme (http//www.ciesm.org/marine/programs/hydrochanges.htm), a network of autonomous conductivity, temperature, and depth (CTD) sensors, deployed on mainly short and easily manageable subsurface moorings, within the core of a certain water mass. The HYDROCHANGES strategy is twofold and develops on different scales. To get information about long-term changes of hydrological characteristics, long time series are needed. But before these series are long enough they allow the detection of links between them at shorter timescales that may provide extremely valuable information about the functioning of the Mediterranean Sea. The aim of this paper is to present the history of the programme and the current set-up of the network (monitored sites, involved groups) as well as to provide for the first time an overview of all the time series collected under the HYDROCHANGES umbrella, discussing the results obtained thanks to the programme.

scholarly journals Pakatan Harapan dan Senario Politik Kelantan: Analisis Pengajaran Politik Pasca PRU 14 (2018-2020)

2021 ◽  
Vol 8 (1) ◽  
pp. 25-55
Author(s):  
Saiyid Radzuwan Syed Sopi
Keyword(s):  
Qualitative Study ◽  
Reference Materials ◽  
Education System ◽  
The State ◽  
Political Strategy ◽  
State Administration ◽  
Set Up ◽  
And Control ◽  
Ruling Party

The 14th general election (GE 14) reveals that Pakatan Harapan (PH) had become a ruling party (2018-2020), but they failed to get any parliamentary or state assembly seats in Kelantan. The failure of PH to expand their influence in Kelantan is due to several traditional factors that are difficult for PH to break it out. This study is a qualitative study and reference materials that are physical and online are used as reference sources. In addition, information regarding political scenario in Kelantan also obtained through interviews with some respondents live in Kelantan. Therefore, this research found that the desire of PH to expand their influence in Kelantan was blurred. This is because PAS wisely set up a long-term political strategy by strengthening the education system under YIK, producing many hardcore supporters or fanatic followers, controlling the ‘surau’ and the mosques according to their needs and control of the state administration. Furthermore, PH needs to make concrete reformations to the party’s management such as producing talented young leaders and fostering a spirit of cooperation among members of the PH coalition if they are still interested in power in Kelantan.

scholarly journals On-Line Fault Detection and Compensation of Hydraulic Driven Machines Using Modelling Techniques

2008 ◽  
Vol 12 (2) ◽  
pp. 111-115
Author(s):  
Chrissanthi Angeli ◽  
◽  
Avraam Chatzinikolaou ◽  
Keyword(s):  
Fault Detection ◽  
Detection System ◽  
Detection Methods ◽  
Time Data ◽  
Actual System ◽  
Incipient Faults ◽  
On Line ◽  
Modelling Techniques ◽  
Drive And Control ◽  
And Control

The development of on-line fault detection methods for drive and control systems is of main importance for the modern production technology. Modelling information improves the reliability of the diagnostic method when it is involved in a fault detection system. In this paper, the use of modelling information for the fault detection of hydraulic driven machines as well as for the compensation of incipient faults is presented. For this purpose a suitable implementation environment was developed that allows the on line interaction of real time data and simulation results and makes possible their direct effect to the actual system.

scholarly journals ROBUST ADAPTIVE CONTROL USING REINFORCEMENT LEARNING FOR NONLINEAR SYSTEM WITH INPUT CONSTRAINTS

2009 ◽  
Vol 12 (16) ◽  
pp. 5-18
Author(s):  
Luy Tan Nguyen ◽  
Thanh Thien Nguyen ◽  
Ha Thi Phuong Nguyen
Keyword(s):  
Reinforcement Learning ◽  
Learning Algorithm ◽  
Robust Stabilization ◽  
Robust Adaptive Control ◽  
Novel Approach ◽  
On Line ◽  
Robust Adaptive ◽  
Associative Law ◽  
Set Up ◽  
And Control

This paper proposes a novel approach to design a controller in discrete time for the class of uncertain nonlinear systems in the presence of magnitude constrains of control signal which are treated as the saturation nonlinearity. A associative law between reinforcement learning algorithm based on adaptive NRBF neural networks and the theory of robust control Ho is set up in a novel control structure, in which the proposed controller allows learning and control on-line to compensate multiple uncertain nonlinearities as well as minimizing both the H. tracking performance index function and the unknown nonlinear dynamic approximation errors. The novel theorem of robust stabilization of the closed-loop system is declared and proved. Simulation results verify the theoretical analysis.

scholarly journals Marine monitoring along the eastern coastal area of the Island of Lesvos, Greece during 2004 in the Framework of MEDPOL III

2013 ◽  
Vol 9 (2) ◽  
pp. 83-97
Keyword(s):  
Marine Environment ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Phase Iii ◽  
Eastern Coast ◽  
Marine Monitoring ◽  
The City ◽  
Term Monitoring

The present survey was carried out in the framework of MEDPOL Phase III (2004 – 2006), aiming to provide recent information for the long-term monitoring of pollution trends in selected susceptible marine environments along the Mediterranean coastline. Information was collected from a network of four stations spaced out along the eastern coast of the Island of Lesvos, Greece, including a high risk station near the harbour of the city of Mytilini. Pollutants in abiotic components of the marine environment (seawater, sediment) as well as in selected marine organisms (M. barbatus and B. boops) were measured. It was found that there is no evidence of substantial pollution of the marine environment (seawater, sediment and fish) with respect to the pollutants measured. However, it was shown that although the uncontrolled discharge of untreated effluents has been reduced since the beginning of the operation of the Mytilini sewage treatment plant in 2001, sediments near the harbour of the city still carry increased loads of metals of anthropogenic origin. Furthermore, the small quantity of untreated sewerage that still flows out in the harbour of the city seems to affect water quality, since a higher mesotrophic character with eutrophic trends was observed in the area.

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