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Hamdy Mohamed S. Al-Zaqri Nabil Sahlabji Taher Eissa Murad Haija Mohammad Abu Alhanash Abdullah M. Alsalme Ali Alharthi Fahad A. Abboud Mohamed 《Catalysis Letters》2021,151(6):1612-1622
Catalysis Letters - To avoid the aggregation problem and activity loss of nickel oxide (NiO) nanoparticles (NPs) in organic reactions, NiO NPs were incorporated into TUD-1 mesoporous material.... 相似文献
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Nabil Channouf Pierre L'Ecuyer 《International Transactions in Operational Research》2012,19(6):771-787
We propose and examine a probabilistic model for the multivariate distribution of the number of calls in each period of the day (e.g., 15 or 30 min) in a call center, where the marginal distribution of the number of calls in any given period is arbitrary, and the dependence between the periods is modeled via a normal copula. Conditional on the number of calls in a period, their arrival times are independent and uniformly distributed over the period. This type of model has the advantage of being simple and reasonably flexible, and can match the correlations between the arrival counts in different periods much better than previously proposed models. For the situation where the number of periods is large, so the number of correlations to estimate can be excessive, we propose simple parametric forms for the correlations, defined as functions of the time lag between the periods. We test our proposed models on three data sets taken from real‐life call centers and compare their goodness of fit to the best previously proposed methods that we know. In the three cases, the new models provide a much better match of the correlations and coefficients of variation of the arrival counts in individual periods. 相似文献
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The effect of nano-sized PbO (10–30 nm) addition on the transport critical current density, Jc of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (PbO)x (x=0–0.15 wt%) was investigated. Jc of PbO added pellet samples showed the maximal value at x=0.05 wt%. Using this result, Ag-sheathed (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (PbO)x/Ag tapes (x=0 and 0.05 wt %) were fabricated by the powder-in-tube (PIT) method. The tapes were sintered for 50 h and 100 h at 845 °C. The temperature dependence of Jc for the non-added and PbO added tapes in applied field was investigated. Jc of the non-added tapes was 4510 A/cm2 at 40 K and 949 A/cm2 at 77 K. Jc of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (PbO)0.05/Ag tape sintered for 100 h was 26,800 A/cm2 at 40 K and 10,700 A/cm2 at 40 K, which was higher than the tapes sintered for 50 h (8590 A/cm2 at 40 K and 1880 A/cm2 at 77 K). Nano-sized PbO added tapes sintered for 100 h showed a higher Jc (more than 10 times) under magnetic field (0–0.75 T) compared with the non-added tape. A combined effect of enhanced flux pinning and improved microstructure led to the significant increase in Jc of the nano-sized PbO added tapes. 相似文献
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Nabil Magbool Jan Biao Huang Aris Espejo Luke Zelmer Fangwei Xu Lee Gulbransen 《加拿大化工杂志》2020,98(10):2125-2136
For the mining based oilsands industry, it is desirable to determine the quality of the ore delivered to the extraction processes in real-time to make optimal operational decisions such as optimal ore blending to achieve maximal bitumen recovery. Currently, the industry determines the real-time ore characteristics for any given shovel Global Positioning System (GPS) location by first determining the shovel elevation from the topological mine map and then using the determined geological coordinates in the 3D geological block model. It should be noted that the block model is built based on the widely spaced core hole samples, and it is updated only on a yearly basis due to high cost of narrower core hole sampling. Thus, the block model predictions are often inaccurate in between the core hole spacing. On the other hand, mining operations data are available that contain accurate ore characteristics information in the already mined area. Therefore, in this work, we present a just-in-time based data-driven modelling strategy that utilizes the recently available mining operations data to obtain reliable ore characteristics given the GPS data. The prediction capability of ore characteristics using the proposed modelling strategy is validated at core hole locations. Further, the prediction of ore characteristics at non-core hole points demonstrate promising results. 相似文献
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Youcef Hadji Abdessabour Benamor Nabil Chiker Adel Haddad Nacer Tala-Ighil Jean-Pierre Erauw Vedi Dupont Arnaud Tricoteaux Christelle Nivot Anthony Thuault Mohamed Hadji 《International Journal of Applied Ceramic Technology》2020,17(2):695-706
In this study, wear and friction behavior of two based-composites from the Ti-Si-C system, (40 wt% TiC; 28 wt% Ti5Si3; 17 wt% Ti3SiC2) and (18 wt% TiC; 26 wt% Ti5Si3; 41 wt% Ti3SiC2) reinforced by 15 wt% of large size SiC (100-150 µm) particles were investigated. The four-phase composites exhibited approximatively the same friction coefficient (µ ~ 0.9) under high loads (10 N and 7 N). The composite with high Ti3SiC2 showed higher wear rate values by one order of magnitude. However, under 1 N, the composite with high TiC content showed a higher running-in period and a lower steady state µ value (0.37 after 1000 m sliding distance). Scanning electron microscopy, Energy Dispersive X-Ray and Raman spectroscopy analysis of the worn surfaces of the two composites revealed that oxidation was the dominant wear mechanism. The oxidation process and the removal kinetics of the oxides during sliding controlled the tribological behavior of the composites. The influence of processing variables on microstructures development and wear mechanisms of the composites is discussed. 相似文献
29.
Commercial fillers, including carbon black (N550), halloysite nanotubes (HNTs), and precipitated silica, were replaced by recycled poly(ethylene terephthalate) powder (R‐PET) in natural rubber (NR) composites. Five different compositions of NR/N550/R‐PET, NR/HNTs/R‐PET, and NR/silica/R‐PET compounds, i.e., 100/20/0, 100/15/5, 100/10/10, 100/5/15, and 100/0/20 parts per hundred rubber (phr), were prepared on a two‐roll mill. The curing behavior, tensile properties, and morphological characteristics of the natural rubber composites were investigated. The results indicated that the replacement of carbon black, HNTs, and silica by R‐PET decreased the tensile strength and tensile modulus, such that NR/silica/R‐PET composites showed the lowest effect, followed by NR/HNTs/R‐PET and NR/N550/R‐PET composites. The negative effect on these properties can be explained by the decrease of crosslink density. The curing results revealed that with the replacement of carbon black by R‐PET, the scorch time and cure time decreased, but that the NR/HNTs/R‐PET and NR/silica/R‐PET composites exhibited the opposite trend. Scanning electron microscopy investigation of tensile fracture surfaces confirmed that the co‐incorporation of N550/R‐PET improved the dispersion of R‐PET and enhanced the interaction between the fillers and NR matrix more than R‐PET and silica/R‐PET hybrid fillers. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers 相似文献
30.
Jie Yuan Ning Song Nabil Farhat Jan Van der Spiegel 《Analog Integrated Circuits and Signal Processing》2009,59(3):287-300
The clustering of spatio-temporal patterns are essential for many applications. Established from the biological analogy of
the cortex, the parametrically coupled logistic map network (PCLMN) provides a viable solution to the clustering problem.
To engineer for a single-chip spatio-temporal pattern clustering system, the highly modular PCLMN is designed in analog circuit.
In this paper, the 0.6 μm 5 V CMOS design of the processing element is presented. The analog design employs self-calibration
techniques to improve the accuracy and robustness of the nonlinear circuits. A fabricated element covers a die area of 0.55
mm2, and consumes 240 mW power at 5 V supply. After calibration, simulation and testing results show that the element fulfills
the system-level requirement of the Cort-X model for driving signals up to 1 MHz. 相似文献