Energy Efficiency Optimization for Wireless Body Area Networks Under 802.15.6 Standard

Wireless Personal Communications - With the attractive applications in e-Health, a booming interest is granted to wireless body area network (WBAN). Through WBAN, healthcare professionals can...     

Numerical assessment of tunnel collapse: a case study of a tunnel at the East–West Algerian highway

Bulletin of Engineering Geology and the Environment - Construction of long tunnels in difficult sites is associated with various risks. Such risks are usually resulted on one hand from the lack of...     

Characterization of the Oxide Scale Formed on T12 Water Wall Tube After Long-term Service in Supercritical Power Plant

Oxidation of Metals - Oxide scale control is one of the critical maintenance issues in fossil fuel power plant. Hence, the water treatment of the feed water has been changed from all-volatile...     

Die umweltfaktoren, die die verbreitung und entwicklung von Chalcalburnus tarichi (PALL. 1881) (Pisces: Cyprinidae) in Burdur-See begrenzen

Burdur Lake, an entirely closed and brackish water lake, having an area of 190 km² and 76 m depth, is located in the “Lakes Region” of Anatolia, 4 km from the west of Burdur city.There have been made many attempts to breed an economically important fish population but all attempts were unsuccessful. During 1946–1948 some hydrobiological investigations were carried out. According to these investigations, hydrobiological conditions of the lake were found to be suitable for Chalcalburnus tarichi (PALL. 1881) (Pisces: Cyprinidae), a fish which is endemic to the Lake Van in eastern Anatolia. Since 1966 an attempt has been made to breed Chalcalburnus tarichi artificially. This attempt was successful, but the economic productivity was not in the estimated level. These fish live in all the depth of the lake, but during the breeding season, they go into fresh water streams flowing into the lake.To find out the reasons of the productivity losses, new hydrobiological investigations have been going on since 1969. Two research stations have been chosen (Fig. 1), where water, plankton and bottom samplings have been collected for hydrobiological research. Nansen bottles were used to take the water samples, in 10 m intervals, from the surface of water towards the bottom. The chemical analysis of water have been done according to the standard methods given in Welcher (1963). The Winkler method is used to find out the amount of dissolved oxygen (Welcher, 1963).Plankton was collected in 10 m intervals by usual type Closing net (20 cm dia, mesh size of 0.05 mm). The amount of plankton per m³ has been calculated according to the Settling methods of Welch (1948).Bottom samples were collected by Ekman's Dredge at four different regions marked (a), (b), (c), (d), on Fig. 1. Samples were wet sieved through four graded sieves (mesh sizes 0.5–2.0 mm). The number of the collected bottom animals per m² were calculated.Observations showed that, the direct flow of waste waters having organic materials from the Burdur Sugar Mill, Milk-Cheese factories and Attar of Rose industries and Hemp (Cannabis sativa) maceration remnants go to the bottom of the lake, therefore, unoxygenated and thereby a hydrogensulphonized water layer is formed by the above mentioned waste products. The unoxygenated water layer level increases 2–2.5 m per year towards the surface. This pollution has caused this unexpected loss of productivity of fish, for this water layer harms the bottom feeding and planktonic organisms and restricts the spreading and development of the adopted Chalcalburnus tarichi (PALL. 1881). It is also clear that this situation is a threat to the future of the lake and its environment.     

Off-design performance evaluation of Hassi R’Mel ISCC power plant

The paper presents a thermodynamic analysis of an existing ISCC power plant when running at off-design operation conditions. The off-design regime is due to changes in air temperature and DNI. The analysis is based on the results of calculations performed by the flow sheet programme ‘Cycle-Tempo’. For off-design modelling, some reasonable assumptions are adopted in regard to the operations of the turbomachines and heat exchangers. The power plant performance is examined when it is running following the operation strategy ‘saving mode’. The complementarily between the solar field and the duct burners (DBs), and the operation of the power plant, in terms of hourly net electricity output and thermal efficiency, are analysed on two representative days, a summer day and a winter day. The key parameters in the study are essentially the HTF mass flow rate, DB fuel consumption, thermal energies supplied by the solar field, and the DBs.     

Automatic speech recognition system for Tunisian dialect

Although Modern Standard Arabic is taught in schools and used in written communication and TV/radio broadcasts, all informal communication is typically carried out in dialectal Arabic. In this work, we focus on the design of speech tools and resources required for the development of an Automatic Speech Recognition system for the Tunisian dialect. The development of such a system faces the challenges of the lack of annotated resources and tools, apart from the lack of standardization at all linguistic levels (phonological, morphological, syntactic and lexical) together with the mispronunciation dictionary needed for ASR development. In this paper, we present a historical overview of the Tunisian dialect and its linguistic characteristics. We also describe and evaluate our rule-based phonetic tool. Next, we go deeper into the details of Tunisian dialect corpus creation. This corpus is finally approved and used to build the first ASR system for Tunisian dialect with a Word Error Rate of 22.6%.     

Control of methane flame properties by hydrogen fuel addition: Application to power plant combustion chamber

This study presents a numerical investigation of the effects of mixing methane/hydrogen on turbulent combustion processes taking place in a burner similar to that integrated in gas turbine power plants. Thereby, in comparison to the reference case where the burner is fuelled by 100% of methane, the variations of the axial velocity field, temperature field and mass fraction of carbon monoxide field are examined for different percentages of hydrogen fuel injection. The computed results, obtained by using the software Fluent-CFD, are compared and validated against experimental reference data. Results show that the hydrogen addition to the methane has an impact on all physical and chemical parameters of the reactive system.     

Factors affecting the intention to use a web-based learning system among blue-collar workers in the automotive industry

This study aims to identify, using an extended Technology-Acceptance Model (TAM), the factors affecting the decision of using a web-based learning system among blue-collar workers in the automotive industry. A structural equation-modeling approach was applied to identify the variables that significantly affect the decision of using the system. Using LISREL 8.54, data collected from 546 blue-collar workers were used to test the proposed research model. Empirical testing of the extended TAM found all paths to be significant in the hypothesized directions, that is, the results of the study strongly support the application of extended TAM in predicting the blue-collar workers’ intention to use a web-based learning system. Among the factors, social influence is a much stronger predictor of user intention compared to others. The study concludes with the implications of this study for managers and recommendations for possible future research.     

Real-time performance models for photovoltaic water pumping systems

This purpose of this paper is to develop and validate a model to accurately predict the cell temperature of a photovoltaic (PV) module that adapts to various mounting configurations, mounting locations, and climates while only requiring readily available data from the module manufacturer. Results from this model are also compared with results from published cell temperature models. The models were used to predict real-time performance from a PV water pumping systems in the desert of Medenine, south of Tunisia using 60-min intervals of measured performance data during one complete year. Statistical analysis of the predicted results and measured data highlights possible sources of errors and the limitations and/or adequacy of existing models, to describe the temperature and efficiency of PV-cells and consequently, the accuracy of performance of PV water pumping systems’ prediction models.