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101.
E. M. S. Salem A. M. El-Naggar M. A. Zewail 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1974,24(12):745-749
Sixteen copper complexes of di-, tri- and hexapeptides containing N2, N4-diaminobutyric acid are studied spectrophotometrically. The λmax, and colour of the complex is independent of the sequence of the amino acid in any of these peptides. The N4-amino group of the A2bu-residues do not participate in complex formation. However, the hydrazide group of di- and tripeptide hydrazides participates in complex formation. 相似文献
102.
The thermal behavior of Illitic-kaolinitic clay for manufacturing of low porosity ceramic Raschig rings was characterized
during the sintering process. The samples were shaped by extrusion method and fired at different temperatures from 1,100 to
1,300 °C. The main physical-chemical transformations were studied by evaluating changes in shrinkage, water absorption, porosity,
mechanical strength, microstructure and mineralogical compositions. The optimum sintering condition was found to obtain maximum
mechanical strength. Chemical resistance of ceramic Raschig rings also was determined according standard method. It was shown
that the better chemical resistance could be attributed to the different mineralogical compositions, in particular with presence
of mullite phase. 相似文献
103.
纵向加劲肋可以有效提高方形或矩形薄壁钢管混凝土柱的整体性能。主要讨论轴压下加劲方形短柱的非线性分析与设计。运用有限元程序ABAQUS进行非线性分析。关于荷载-位移曲线和极限强度的试验与分析结果具有良好的一致性。运用这个模型同时也对柱的性能进行了研究,讨论板的宽厚比限值和加劲肋刚度需求,以及运用现有规范预测加劲复合柱承载能力的可行性。 相似文献
104.
105.
Effects of natural blends of garlic and eucalypt essential oils on biogas production of four fibrous feeds at short‐term of incubation in the ruminal anaerobic biosystem
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106.
107.
Ahmed H. Salem Ruth Brunstermann Thorsten Mietzel Renatus Widmann 《International Journal of Hydrogen Energy》2018,43(10):4856-4865
This study investigated the effect of pre-treatment and hydraulic retention time (HRT) on biohydrogen production from organic wastes. Various pre-treatments including thermal, base, acid, ultrasonication, and hydrogen peroxide were applied alone or in combination to enhance biohydrogen production from potato and bean wastewater in batch tests. All the pre-treated samples showed higher hydrogen production than the control tests. Hydrogen peroxide pre-treatment achieved the best results of 939.7 and 470 mL for potato and bean wastewater, respectively. Continuous biohydrogen production from sucrose, potato and bean wastewater was significantly influenced by reducing the HRT as 24, 18 and 12 h. Sucrose and potato showed similar behavior, where the hydrogen production rate (HPR) increased with decreasing the HRT. Optimum hydrogen yield results of 320 mL-H2/g-VS (sucrose) and 150 mL-H2/g-VS (potato) were achieved at HRT of 18 h. Bean wastewater showed optimum HPR of 0.65 L/L.d with hydrogen yield of 80 mL-H2/g-VS at 24 h HRT. 相似文献
108.
Houda Daoud Sawssen Lahiani Samir Ben Salem Mourad Loulou 《International Journal of Electronics》2020,107(4):659-682
ABSTRACTWith the aggressive scaling of integrated circuit technology, parametric estimation is a critical task for designers who looked for solutions to the challenges of some Nanoscale CMOS parameters. This paper presented the prediction of primary parameters of CMOS transistor for 16 nm to 10 nm process nodes using both of Bisquare Weights (BW) method and a novel recursive least squares (RLS) parameter estimation algorithm. The proposed RLS algorithm consists of the minimisation of a quadratic criterion relating to the prediction error in order to attain the best estimated parameters of the developed mathematical model. The obtained results thanks to the proposed RLS algorithm were better than those reached using the BW method. Comparisons between Predictive Technology Model (PTM) data and parameters estimated with RLS algorithm were made to check the validity and the consistency of the proposed algorithm. These predicted primary parameters were helpful to estimate and to optimise the performances of the Variable Gain Amplifier (VGA) which was a basic circuit element with a key role in the design of new upcoming receivers. 相似文献
109.
Support vector machine based decision for mechanical fault condition monitoring in induction motor using an advanced Hilbert-Park transform 总被引:1,自引:0,他引:1
In this work we suggest an original fault signature based on an improved combination of Hilbert and Park transforms. Starting from this combination we can create two fault signatures: Hilbert modulus current space vector (HMCSV) and Hilbert phase current space vector (HPCSV). These two fault signatures are subsequently analysed using the classical fast Fourier transform (FFT). The effects of mechanical faults on the HMCSV and HPCSV spectrums are described, and the related frequencies are determined. The magnitudes of spectral components, relative to the studied faults (air-gap eccentricity and outer raceway ball bearing defect), are extracted in order to develop the input vector necessary for learning and testing the support vector machine with an aim of classifying automatically the various states of the induction motor. 相似文献
110.
N. Loudhaief H. Labiadh E. Hannachi M. Zouaoui M. Ben Salem 《Journal of Superconductivity and Novel Magnetism》2018,31(8):2305-2312
Cadmium sulfide (CdS) nanoparticles were synthesized by hydrothermal process and have been characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), and energy-dispersive x-ray spectroscopy (EDXS) system. The effect of added CdS nanoparticles on the superconducting properties and flux pinning capability in (Bi,Pb)2Sr2Ca2Cu3Oy system (denoted as (Bi,Pb)-2223) has been reported. Hydrothermal method is an effective route to synthesize CdS nanoparticles with good crystallinity and having average grain size of about 12 nm. Then, small amounts (0–0.4 wt%) of nanosized CdS particles were added to Bi-2233 samples using a solid-state reaction route. The transport critical current densities and the electrical resistivity ρ(T, H) were performed using the four-probe technique. The results show that samples sintered by small amount of CdS nanoparticles (≤?0.3 wt%) exhibit the higher critical current densities and energy pinning in applied magnetic fields compared to free added sample. Consequently, the addition of CdS could introduce effective pinning centers which account for the improvement in superconducting properties in the Bi-2223 materials. 相似文献