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11.
Zazoua Hanane Touahra Fouzia Sehailia Moussa Chebout Redouane Lerari Djahida Bachari Khaldoun Saadi Adel 《Research on Chemical Intermediates》2019,45(5):3273-3290
Research on Chemical Intermediates - Delafossite mixed metal oxides of the form BaCuO2 and BaCu1M1?xO2 (M?=?Ni, Fe and Co) were successfully synthesized following a sol–gel... 相似文献
12.
Rana Obaidat Nawzat Al-Jbour Khaldoun Al-Sou’d Kamal Sweidan Mayyas Al-Remawi Adnan Badwan 《Journal of solution chemistry》2010,39(4):575-588
Depolymerization for different time intervals of high molecular weight chitosan using 2 mol⋅L−3 HCl resulted in low molecular weight (LMW) chitosan of 6, 10, 13, 18, and 30 kDa. These were studied using the FT-IR which
indicated that the depolymerization process did not influence the chemical structure. LMW chitosan increases the surface tension
of water but adjusting the ionic strength (1% NaCl) caused LMW chitosan to reduce the water surface tension. The zeta potential
increased with increasing concentration up to a maximum in 1% NaCl solutions. Particle size showed a reduction in size with
increasing concentration. This behavior in reduction of particle size was similar to that for the stiffness parameters. These
physico-chemical properties showed that LMW chitosan was present in low concentration in its extended form while in higher
concentrations it adopted a more contracted form. This change in conformation was confirmed by using molecular modeling where
LMW chitosan is ribbon-like to rod-like in solution but becomes rod-like to spherical at the gas–liquid interface. 相似文献
13.
This article addresses the stock market as a complex system. The complexity of the stock market arises from the structure of the environment, agent heterogeneity, interactions among agents, and interactions with market regulators. We develop the idea of a meta‐model, which is a model of models represented in an agent‐based model that allows us to investigate this type of market complexity. The novelty of this article is the incorporation of various complexities captured by network theoretical models or induced by investment behavior. The model considers agents heterogeneous in terms of their strategies and investment behavior. Four investment strategies are included in the model: zero‐intelligence, fundamental strategy, momentum (trend followers), and adaptive trading strategy using the artificial neural network algorithm. In terms of behavior, the agents can be risk averse or loss occupied with overconfidence or conservative biases. The agents may interact with each other by sharing market sentiments through a structured scale‐free network. The market regulator controls the market through various control tools such as the risk‐free rate and taxation. Parameters are calibrated to the S&P500. The calibration is implemented using a scatter search heuristic approach. The model is validated using various stylized facts of stock return patterns such as excess kurtosis, auto‐correlation, and ARCH effect phenomena. Analysis at the macro and micro level of the market was performed by measuring the sensitivity of volatility and market capital and investigating the wealth distributions of the agents. We found that volatility is more sensitive to the model parameters than to market capital, and thus, the level of volatility does not affect market capital. In addition, the findings suggest that the efficient market hypothesis holds at the macro level but not at the micro level. © 2016 Wiley Periodicals, Inc. Complexity 21: 530–554, 2016 相似文献
14.
Khaldoun A. Al-Sou’od 《Journal of solution chemistry》2008,37(1):119-133
Phase solubility diagrams (PSDs) and molecular mechanical (MM) modeling were used to study the complexation of hydrocortisone
(HCor) with β-cyclodextrin (β-CD). The phase solubility profile of HCor with β-CD was classified as the Bs-type. PSDs revealed a six-fold increase in HCor water solubility upon addition of 7 mmol⋅dm−3
β-CD concentration (solubility in 7 mmol⋅dm−3 of β-CD/solubility in water). The thermodynamic study shows the complexation process is exothermic, with a ΔH value of −5.28 kJ⋅mol−1. MM calculations were used to predict the optimal stoichiometry of the complex formed as well as the possible orientations
of HCor inside the β-CD cavity. The complexes prepared were analyzed through chemical analysis, which provides evidence for the 1:1 complexation
of HCor/β-CD.
Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users. 相似文献
15.
Approximate analytical solution for the Zakharov–Kuznetsov equations with fully nonlinear dispersion
In this paper, variational iteration method (VIM) is used to obtain numerical and analytical solutions for the Zakharov–Kuznetsov equations with fully nonlinear dispersion. Comparisons with exact solution show that the VIM is a powerful method for the solution of nonlinear equations. 相似文献
16.
Ala A. Alhusban Alaa M. Hammad Lujain F. Alzaghari Aliaa I. Shallan Khaldoun Shnewer 《Biomedical chromatography : BMC》2023,37(1):e5513
Tobacco smoking is a preventable main cause of fatal diseases. Accurate measurements of the effects it has on neurotransmitters are essential in developing new strategies for smoking cessation. Moreover, measurements of neurotransmitter levels can aid in developing drugs that counteract the effects of smoking. The aim of this study is to develop and validate a fast, simultaneous and sensitive method for measuring the levels of neurotransmitters in rat brain after the exposure of tobacco cigarettes. The selected neurotransmitters include dopamine, GABA, serotonin, glutamine and glutamate. The method is based on high-performance liquid chromatography–tandem mass spectrometry. Chromatographic separation was achieved within 3 min using a Zorbax SB C18 column (3.0 × 100 mm, 1.8 μm particle size). The mobile phase consisted of HPLC-grade water and acetonitrile each containing 0.3% heptafluorobutyric acid and 0.5% formic acid at gradient conditions. The linear range was 0.015–0.07, 825–7,218, 140–520, 63.42–160.75 and 38.25 × 103 to 110.35 × 103 ng/ml for dopamine, GABA, serotonin, glutamine and glutamate, respectively. Inter- and intra-run accuracy were in the range 97.82–103.37% with a precision (CV%) of ≤0.90%. The results revealed that 4 weeks of cigarette exposure significantly increased neurotransmitter levels after exposure to tobacco cigarettes in various brain regions, including the hippocampus and the amygdala. This increase in neurotransmitters levels may in turn activate the nicotine dependence pathway. 相似文献