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21.
Foued Ftaiti Asma Kacem Nadia Jaidane Zouhair Tabka Mohamed Dogui 《Applied ergonomics》2010,41(6):806-811
This study examined the effect of hyperthermia on brain electrical activity measured with encephalography during prolonged exhaustive exercise in a group of sedentary women (VO2max = 35 ± 4 mL kg min−1). Two strenuous cycling exercises were performed either in neutral (N-Ex) or in heat (H-Ex) conditions. Tympanic temperature (Tty), heart rate (HR), body mass loss (BML), plasma volume decrease, and brain electrical activity [EEG: α (8–13 Hz) and β(13–30 Hz)-band and α/β index of fatigue: the ratio between EEG activity in the α band and β-band] were recorded throughout the cycling sessions. The Tty increase 1.0 °C in the N-Ex and 1.8 °C in H-Ex. HR increased in both sessions but with significantly higher values during the H-Ex session when compared with the N-Ex session (p < 0.001) (from 85 ± 4 beats min−1 to 164 ± 6 beats min−1 and from 83 ± 6 beats min−1 to 181 ± 8 beats min−1, respectively in N-Ex and in H-Ex). This was associated with a significantly higher BML (p < 0.05) and a higher plasma volume decrease in the H-Ex session (p < 0.01). The α/β index increased significantly during both trials particularly during the H-Ex session (p < 0.05). This was associated with a significant decrease of time to exhaustion (−34%). We suggest that exhausting work in the heat induced a change in gross brain activity (alpha/beta ratio) compared to a longer, less thermally demanding exposure. Fatigue in the heat could be attributed to central factors as well as thermal, cardiac and hydro-electrolytic impairment. 相似文献
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Compositional specification of real time embedded systems by priority time Petri Nets 总被引:1,自引:1,他引:0
Adel?MahfoudhiEmail author Yessine?Hadj?Kacem Walid?Karamti Mohamed?Abid 《The Journal of supercomputing》2012,59(3):1478-1503
An important key challenge in Embedded Real Time Systems (ERTS) analysis is to provide a seamless scheduling strategy. Formal
methods for checking the temporal characteristics and timing constraints at a high abstraction level have proven to be useful
for making the development process reliable. In this paper, we present a Petri Net modeling formalism and an analysis technique
which supports not only systems scheduling analysis but also the compositional specification of real time systems. The proposed
Priority Time Petri Net gives determinism aspect to the model and accelerates its execution. Indeed, a compositional specification
of a PTPN for complex application and multiprocessor architecture that solves the problem of hierarchy is presented. 相似文献
23.
Zidane F Drogui P Lekhlif B Bensaid J Blais JF Belcadi S El Kacemi K 《Journal of hazardous materials》2008,155(1-2):153-163
The colour and colour causing-compounds has always been undesirable in water for any use, be it industrial or domestic wastewaters. The discharge of such effluents causes excessive oxygen demand in the receiving water and then a treatment is required before discharge into ecosystems. This study examined the possibility to remove colour causing-compounds from effluent by chemical coagulation, in comparison with direct electrocoagulation. The inorganic coagulants (C1, C2 and C3) in the form of dry powder tested, were respectively produced from electrolysis of S1 = [NaOH (7.5 × 10−3 M)], S2 = [NaCl (10−2 M)], and S3 = [NaOH (7.5 × 10−3 M) + NaCl (10−2 M)] solutions, using sacrificial aluminium electrodes operated at an electrical potential of 12 V. Reactive textile dye (CI Reactive Red 141) was used as model of colour-causing compound prepared at a concentration of 50 mg l−1. The best performances of dye removal were obtained with C2 having a chemical structure comprised of a mixture of polymeric specie (Al45O45(OH)45Cl) and monomeric species (AlCl(OH)2·2H2O and Al(OH)3). The removal efficiency (RA) evaluated by measuring the yields of 540 nm-absorbance removal varied from 41 to 96% through 60 min of treatment by imposing a concentration of C2 ranging from 100 to 400 mg l−1. The effectiveness of the treatment increased and the effluent became more and more transparent while increasing C2 concentration. The comparison of chemical treatment using C2 coagulant and direct electrocoagulation of CI Reactive Red 141 containing synthetic solution demonstrated the advantage of chemical treatment during the first few minutes of treatment. A yield of 88% of absorbance removal was recorded using C2 coagulant (400 mg l−1) over the first 10 min of treatment, compared to 60% measured using direct electrocoagulation while imposing either 10 or 15 V of electrical potential close to the value (12 V) required during C2 production. However, at the end of the treatment (after 60 min of treatment), CI Reactive Red 141 pollutant was completely removed from solution (540 nm-absorbance removal of 100%) using direct electrochemical treatment, compared to 96.4% of absorbance removed while treating dye-containing synthetic solution by means of C2 coagulant. 相似文献
24.
This paper describes the treatment of gold ores via the bauxite waste mud used as a pH modifier in the cyanidation of gold. The red mud is irrefutable in modifying the pH of gold ore sludges. So any gold contained in the red mud is concentrated by gravity separation and is recovered along with gold from the gold ore. Carbon tests are carried out on cyanide leach solutions to determine the level of deactivation resulted by organics in the bauxite waste mud. 相似文献
25.
Ibrahim Jallouli Abdelkader Krichen Afef Bougharriou Kacem Sa? 《The International Journal of Advanced Manufacturing Technology》2011,55(5-8):641-648
In this work, countersinking which is the manufacturing operation used to enlarge the side of an existing hole is studied. A finite element model is built in order to get the normalized dimensions of the countersink. The obtained countersink allows to the head of screws or rivets to sit flush with the surface with the surrounding material. A case study is detailed in order to show the effect of the pertinent parameters. The procedure is summarized by the construction of a single diagram in which the coupled effects of the different parameters are shown. A fully automatic procedure can be built in the light of this analysis. 相似文献
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M Jouini R Ksontini MJ Kacem S Haouet A Ammous F Gargouri H Houissa Z Ben Safta AB Ammar S Belaid 《Canadian Metallurgical Quarterly》1996,31(6):341-345
PURPOSE: The purpose of this project was to increase use of the Physician Data Query and Patient Information File services of the National Cancer Institute in a clinical setting. OVERVIEW: A patient education demonstration project was conducted at the University of Rochester Cancer Center using a touch-screen computer program called CancerHelp. Two computers were purchased, one stationed in the Patient Library at the University of Rochester Cancer Center and one circulated to three affiliated hospitals. Demographic information was asked at the beginning of the program and an evaluation was elicited at the end of the program. All information was given voluntarily; users of the system could bypass the questions if they wished. The computer program was very well received by patients and their families. The program was used 1758 times over 6 months. CLINICAL IMPLICATIONS: A touch-screen computer program can be an effective method for distributing cancer information. 相似文献
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In this article, we consider a single-machine scheduling problem with one unavailability period, with the aim of minimizing the weighted sum of the completion times. We propose three exact methods for solving such a problem: a branch-and-bound method based on new properties and lower bounds, a mixed integer programming model, and a dynamic programming method. These methods were coded and tested on randomly generated instances, and their performances were analyzed. Our numerical experiments show that the branch-and-bound method and the dynamic programming method are complementary. Using these approaches, we are able to solve problems with up to 3000 jobs within a reasonable computation time. 相似文献
30.
In a recent paper [Theoretical Computer Science 363, 257–265], He, Zhong and Gu considered the non-resumable case of the scheduling problem with a fixed non-availability interval under the non-resumable scenario. They proposed a polynomial time approximation scheme (PTAS) to minimize the total completion time.In this paper, we propose a fully polynomial-time approximation scheme to minimize the total weighted completion time. The FPTAS has O(n2/ε2) time complexity, where n is the number of jobs and ε is the required error bound. The proposed FPTAS outperforms all the previous approximation algorithms designed for this problem and its running time is strongly polynomial. 相似文献