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Ammar M. A. Abu znaid Mohd. Yamani Idna Idris Ainuddin Wahid Abdul Wahab Liana Khamis Qabajeh Omar Adil Mahdi 《Wireless Networks》2017,23(3):737-747
In recent years, the number of applications utilizing mobile wireless sensor networks (WSNs) has increased, with the intent of localization for the purposes of monitoring and obtaining data from hazardous areas. Location of the event is very critical in WSN, as sensing data is almost meaningless without the location information. In this paper, two Monte Carlo based localization schemes termed MCL and MSL* are studied. MCL obtains its location through anchor nodes whereas MSL* uses both anchor nodes and normal nodes. The use of normal nodes would increase accuracy and reduce dependency on anchor nodes, but increases communication costs. For this reason, we introduce a new approach called low communication cost schemes to reduce communication cost. Unlike MSL* which chooses all normal nodes found in the neighbor, the proposed scheme uses set theory to only select intersected nodes. To evaluate our method, we simulate in our proposed scheme the use of the same MSL* settings and simulators. From the simulation, we find out that our proposed scheme is able to reduce communication cost—the number of messages sent—by a minimum of 0.02 and a maximum of 0.30 with an average of 0.18, for varying node densities from 6 to 20, while nonetheless able to retain similar MSL* accuracy rates. 相似文献
254.
Wahid Herchi Faouzi Sakouhi David Arráez-Román Antonio Segura-Carretero Sadok Boukhchina Habib Kallel Alberto Fernández-Gutierrez 《Journal of the American Oil Chemists' Society》2011,88(8):1135-1142
The phenolic fraction of flaxseed oil was quantified during the development of three varieties (H52, O116 and P129). Seed
samples were collected at regular intervals from 7 to 56 days after flowering (DAF). During oilseed processing, less polar
compounds are co-extracted with oil. The methanolic extracts were obtained by solid phase extraction. Separation of phenolic
compounds was conducted by high-performance liquid chromatography-mass spectrometry. The main phenolic compounds detected
during maturation were: diphyllin, pinoresinol, matairesinol, secoisolariciresinol, vanillic acid, ferulic acid and vanillin.
The highest amount of lignans (6.74 mg of analyte/kg of flaxseed oil) was detected at 7 DAF in P129 variety. The maximum level
of phenolic acids (2.57 mg of analyte/kg of flaxseed oil) was reached at 7 DAF in P129 which had also the highest content
of simple phenols (1.37 mg of analyte/kg of flaxseed oil) at the same date after flowering. At full maturity, the content
of phenolic compounds in three varieties ranged from 0.26 to 0.36 mg of analyte/kg of flaxseed oil. The highest content of
total phenolic compounds using the Folin–Ciocalteu method was detected in P129 variety (196.42 mg CAEs/kg of flaxseed oil)
at 7 DAF. Results of this study indicate that flaxseed oils contain different amounts of phenolic compounds using different
methods. 相似文献
255.
Faouzi Sakouhi Wahid Herchi Khaled Sbei Christelle Absalon Sadok Boukhchina 《International Journal of Food Science & Technology》2011,46(11):2281-2286
The present investigation was carried out for the analysis of hydrocarbon compounds of Tunisian Meski olives. The hydrocarbon fraction of the oils was found to contain twelve n‐alkanes (C22–C36) and squalene. Results from the quantitative characterisation of the oils revealed that squalene was the most abundant hydrocarbon compound, at all development stages of Meski olive, accounting for more 92% of total hydrocarbons. Pentacosane (C25), heptacosane (C27) and tricosane (C23) represented the major compounds of n‐alkanes. The highest accumulation of n‐alkanes and squalene was observed at early stages of olive development [before 21st week after the flowering date (WAFD)]. The greatest decrease of these components occurred between 21st and 26th WAFD of the olives. At complete maturity of the fruit, the level of squalene and total n‐alkanes was 126.52 and 9.13 mg per 100 g oil, respectively. Hence, the content of n‐alkanes and squalene was remarkably influenced by the ripeness process of olive. 相似文献
256.
Mahmoud A. Youssef Seddik S. Wahid Maher A. Mohamed Ahmed A. Askalany 《Applied Energy》2009,86(12):2644-2650
The present study investigates the combustion of four kinds of biomass in a circulating fluidized bed. The combustion chamber is a steel cylinder with 145 mm inner diameter and 2 m height. Tests were conducted on wheat straw, sawdust-wood, cottonseed burs, and corncobs. Excess air was varied for each fuel. Temperature, heat flux and gas emissions were measured along the combustion chamber and at the chimney inlet. Results showed that sawdust-wood produces the highest values of CO emissions (about 3000 mg/Nm3). On the other hand, cottonseed burs produce the lowest values of CO emissions (about 250 mg/Nm3). The SO2 emissions were very low in all tests (less than 20 mg/Nm3). The lowest emission value occurred at an excess air ratio (EA) of 1.24 except for cottonseed burs where it was 1.4. 相似文献
257.
This paper reviews the theory and evaluation of ultraprecision-machined surfaces. Carbide and single crystalline diamond tools were used to machine brittle, ductile and metal matrix composites in macro and micro scales. Data for ductile mode micromachining of brittle materials (silicon, Al2O3, SiC) and ductile materials (Cu-Be, Cu-Zn, Al-Si) were presented and compared. Models for surface finish were presented and evaluated with experimental data. The surface finish and surface integrity were characterized with scanning electron microscopy, scanning probe microscopy, and profilometry techniques. The models agreed with experimental data for ductile materials machined with a diamond tool in macro scale, but deviated from the data at micro scale because of the effect of the material microstructure. The drawbacks of the models were highlighted, i.e., they should include the crystalline orientation of the material and the effect of microstructure on surface finish. 相似文献
258.
The polarographic and electrocapillary curve methods have been used to determine the maximum suppression point (MSP), polarographic
micelle point (PMP) and critical micelle concentration (cmc) of some polyoxyethylated nonionic surfactants, viz., Tween 20,
Tween 40 and Tween 80. The cmc values thus obtained have been compared with the values obtained by surface tension, iodine
solubilization, spectral dye and radiometric methods. 相似文献
259.
260.
FN de Wet JJ Gerber AP L?tter JG van der Watt TG Dekker 《Canadian Metallurgical Quarterly》1998,24(5):447-453
Fanconi anaemia (FA) is an accepted indication for treatment with allogeneic HLA-identical BMT. Most patients, however, lack a suitable HLA-identical donor. In our centre, six FA patients were transplanted with a matched unrelated donor. Due to hypersensitivity to DNA cross-linking agents, a low-dose cyclophosphamide (CY) and thoraco-abdominal irradiation (TAI) regimen is recommended for conditioning in FA. We added Ara-C upfront and anti-T cell antibodies to enhance engraftment and to prevent GVHD, in combination with T cell depletion in four out of six of the first transplants. One patient did not engraft. In three patients rejection was observed. In three of these four patients a second BMT, using full bone marrow grafts, resulted in successful engraftment. The other patient died before a second BMT could be performed. The incidence and severity of acute GVHD was low: only one patient with grade III acute GVHD was seen. Two out of four surviving patients suffered from chronic GVHD. Four patients survived (median survival time 43 months after BMT), three with good and one with acceptable quality of life. Two patients died, one patient due to adenoviral reactivation with multi-organ failure, and one due to sepsis complicated by ARDS. In conclusion, MUD BMT is feasible in FA patients with bone marrow failure in whom no HLA-identical sibling donor is available. In our study group, the major problem was graft rejection, despite the administration of a combination of graft enhancing anti-T cell antibodies. Multicentre studies are needed to determine a more intensive, but still tolerable, conditioning regimen. 相似文献