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91.
JPC – Journal of Planar Chromatography – Modern TLC - The merits of chemometrics in categorizing different Egyptian olive chemovarieties based on their compositional integrity were... 相似文献
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Nehal F. Farid Ibrahim A. Naguib Nessreen S. Abdelhamid Basma H. Anwar Maimana A. Magdy 《Journal of separation science》2020,43(12):2330-2337
A novel ecofriendly, cost and time saving high‐performance thin‐layer chromatographic method was developed and validated for simultaneous determination of metoclopramide, ergotamine, caffeine, and paracetamol in bulk and pharmaceutical formulation. The separation was carried out on silica gel plates, using ethyl acetate:ethanol:ammonia (9:1:0.1, v/v/v) as a developing system. Ultraviolet detection was carried out at 272 nm. The resulting retention times were 0.15, 0.36, 0.49, and 0.74 min for metoclopramide, ergotamine, caffeine, and paracetamol, respectively. The greenness profile assessment was achieved to the proposed method to evaluate its greenness characters to the environment with acceptable results. Validation parameters were checked according to International Conference of Harmonization guidelines to achieve the international requirements for quality control analysis of the proposed drugs. 相似文献
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Canan Atilgan Ibrahim Inanc Ali Rana Atilgan 《Journal of Polymer Science.Polymer Physics》2012,50(23):1653-1662
We study geometric and energetic factors that partake in modifying properties of polymeric melts via inserting well‐dispersed nanoscopic particles (NP). Model systems are cis‐1,4‐polybutadiene melts including a single atomic clusters of size varied in the range 10–150 atoms (3–7 Å in radius; 0.1–1.5% v/v). We modify the interactions between the chains and the particle by tuning attractive van der Waals interactions. Using molecular dynamics, we study equilibrium fluctuations and dynamical properties at the interface. The NPs move in the polymer matrix in two different regimes corresponding to trapped and free diffusion, depending on the NP size. Furthermore, degree of crowding around the NP by the polymer chains is quantified. Effect of NP size and interaction strength both on volume and volumetric fluctuations is manifested in mechanical properties, quantified here by bulk modulus, K. Tuning NP size and nonbonded interactions results in ~15% enhancement in K by addition of a maximum of 1.5% v/v NP. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
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Ezzidine Ibrahim Ibrahim Abd-ellah Leyla S. Shaw Ibrahim Alnaimi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):109-114
Abstract The formation and subsequent fragmentation of spirocyclodiphosph(V)azanes (II-III) has been studied by mass spectrometry using the link-field scan technique and structural inferencies are drawn from these data. 31P nmr measurements for compound (III) are also described. 相似文献
99.
Optimization of neural network for ionic conductivity of nanocomposite solid polymer electrolyte system (PEO-LiPF6-EC-CNT) 总被引:1,自引:0,他引:1
Mohd Rafie Johan Suriani Ibrahim 《Communications in Nonlinear Science & Numerical Simulation》2012,17(1):329-340
In this study, the ionic conductivity of a nanocomposite polymer electrolyte system (PEO-LiPF6-EC-CNT), which has been produced using solution cast technique, is obtained using artificial neural networks approach. Several results have been recorded from experiments in preparation for the training and testing of the network. In the experiments, polyethylene oxide (PEO), lithium hexafluorophosphate (LiPF6), ethylene carbonate (EC) and carbon nanotubes (CNT) are mixed at various ratios to obtain the highest ionic conductivity. The effects of chemical composition and temperature on the ionic conductivity of the polymer electrolyte system are investigated. Electrical tests reveal that the ionic conductivity of the polymer electrolyte system varies with different chemical compositions and temperatures. In neural networks training, different chemical compositions and temperatures are used as inputs and the ionic conductivities of the resultant polymer electrolytes are used as outputs. The experimental data is used to check the system’s accuracy following the training process. The neural network is found to be successful for the prediction of ionic conductivity of nanocomposite polymer electrolyte system. 相似文献
100.
Stig E. Friberg Ibrahim Kayali Tatang Suhery Linda D. Rhein F. Anthony Simion 《Journal of Dispersion Science and Technology》2013,34(3):337-347
Water uptake in natural and reaggregated stratum corneum was determined by weight difference after storage in an atmosphere of controlled relative humidity. Interlayer spacing in separated lipids as a function of their water content was determined by low-angle X-ray diffractometry. These values were used as a calibration curve to determine the water content of the lipid bilayers in reaggregated stratum corneum. The results revealed different behavior of the lipid models compared to natural lipids of the stratum corneum. The additional water taken up after reaggregation of equilibrated lipids and proteins, was equally partitioned between the protein and the natural lipid fraction, while the models gave a proportionally higher water uptake into the lipids at high relative humidity. It is obvious that the models, so far, do not mimic all the properties of the natural stratum corneum lipids. 相似文献