PETROGRAPHICAL AND GEOCHEMICAL STUDIES OF CRETACEOUS CARBONATE ROCKS, AIN ZALAH OILFIELD, NORTH IRAQ

Petrographical and geochemical studies of 135 core rock samples from Cretaceous formations at the Ain Zalah oilfield suggests that the carbonate rocks contain different percentages of dolomite and calcite.
Dolomitisation, stylolisation and neomorphic processes were observed in these formations. This study suggests that the Upper Cretaceous formations were deposited in a deep-sea environment under low-energy conditions, while the Middle and Lower Cretaceous formations were deposited in a shallow-marine environment associated with tidal conditions far from wave attack.     

An Optimal User Selection Scheme for Cooperative NOMA Networks with SWIPT

Wireless Personal Communications - In this paper, we propose an optimal user selection scheme for cooperative non-orthogonal multiple access (NOMA) networks with simultaneous wireless information...     

On the applicability of a semi-analytical approach to determining the transient electron transport response of gallium arsenide, gallium nitride, and zinc oxide

We critically examine the applicability of the semi-analytical approach of Shur (M. Shur, Electron Lett 12, 615 (1976)) in evaluating the transient electron transport response of gallium arsenide, gallium nitride, and zinc oxide. In particular, we contrast results obtained using this semi-analytical approach of Shur with those obtained using Monte Carlo simulations of the electron transport. Our approach will be to examine the response of an ensemble of electrons to the application of a constant and uniform applied electric field. For the purposes of this analysis, three aspects of the transient electron transport response will be considered: (1) the dependence of the electron drift velocity on the time elapsed since the onset of the applied electric field, (2) the dependence of the average electron energy on the time elapsed since the onset of the applied electric field, and (3) the dependence of the average electron displacement on the time elapsed since the onset of the applied electric field. The results obtained show that this semi-analytical approach of Shur produces results that are very similar to those produced using Monte Carlo simulations. Thus, this semi-analytical approach of Shur should be applicable for the treatment of non-uniform and time-varying electric fields, making it a useful tool for the treatment of the transient electron transport response within electron device configurations.     

Receptor-ligand-based specific cell adhesion on solid surfaces: hippocampal neuronal cells on bilinker functionalized glass

Cell adhesion through binding between specific cell membrane receptors and corresponding cell-adhesion-molecule (CAM)-coated solid surfaces is examined. The morphology of surfaces at various modification steps leading to functionalization with cell-binding CAMs is characterized. In one week neuron cultures, enhanced growth on surfaces modified with neuron-binding versus astrocyte-binding CAMs is observed. However, nonspecific adhesion on a poly-D-lysine-coated positive control surface is found to be even higher. Potential reasons and further studies needed are discussed.     

Public news announcements and quoting activity in the Euro/Dollar foreign exchange market

The effect of public news announcements on dealers’ quoting activity is analyzed with the multivariate double autoregressive conditional Poisson model. Quoting activity is measured by the frequency of price revisions in the Euro/Dollar foreign exchange market. The multivariate double autoregressive conditional Poisson model is designed for time series of count data. It is based on the double Poisson distribution, which can be both over- and underdispersed. The main findings are first a significant interaction between dealers’ quoting activity, which confirms hot potato trading. Second, news announcements have a different impact on the quoting activity of different banks. Third, impulse-response functions to news announcements show the dynamic nature of the reaction to these news releases.     

Pellet size dependent steam reforming of polyethylene terephthalate waste for hydrogen production over Ni/La promoted Al2O3 catalyst

The effect of different pellet sizes of nickel (Ni) and lanthanum (La) promoted Al₂O₃ support on the catalytic performance for selective hydrogen production from polyethylene terephthalate (PET) plastic waste via steam reforming process has been investigated. The catalysts were prepared by impregnation method and were characterized using XRD, BET, TPD-CO₂, TPR, SEM, EDX, TEM and TGA. The results showed that NiLa-co-impregnated Al₂O₃ catalyst has excellent activity for the production of hydrogen. Feed conversion of 88.53% was achieved over 10% Ni/Al₂O₃ catalyst which increased to 95.83% in the case of 10% Ni-5% La/Al₂O₃ catalysts with a H₂ selectivity of 70.44%. The catalyst performance in term of gas production and feed conversion was further investigated under various operating parameters, e.g., feed flow-rate, and catalyst pellet size. It was found that at 0.4 ml/min feed flow rate, highest feed conversion and H₂ selectivity were achieved. The Ni particles, which are the noble-based active species are highly effective, thus offered good hydrogen production in the phenol-PET steam reforming process. Incorporation of La as a promoter in Ni/Al₂O₃ catalyst has significantly increased the catalyst reusability with prolonged stability. The NiLa/Al₂O₃ catalyst with larger size showed remarkable activity due to the presence of significant temperature gradients inside the pellet compared to smaller size. Additionally, the catalyst showed only slight decrease in H₂ selectivity and feed conversion even after 24 h, although production of carbon nanotubes was evidenced on its surface.     

Characteristics of Cell Wall Structure of Green Beans During Controlled Freezing Point Storage

Controlled freezing-point storage means that the storage temperature is in a non-freezing temperature zone between the freezing point of water and food. It has been demonstrated that controlled freezing-point storage can prolong the storage-life of fresh food. Green beans (Phaseolus vulgaris L.) have been planted extensively in the northeast region of China and harvested seasonally. Degradation of cell wall polysaccharides has greatly affected the texture properties of the green bean cell walls. During controlled freezing-point storage, activities of cellulase, pectin methyl esterase, and polygalacturonase were inhibited effectively. It resulted in a slow degradation of cellulose and pectin, less expansion of the cell wall, and less dissolution of pectin layers. As a result, the web structure of the cell wall was preserved. At controlled freezing temperature, the hardness of green beans decreased slightly. Homogalacturonan of chelate pectin was degraded into galacturonic acid, and the side chains of the soluble alkali pectin were degraded into arabinose and galactose. At the later stage of controlled freezing-point storage, the web structure of the cell wall polysaccharides was destroyed. However, the pectin degradation in the green beans was inhibited significantly during controlled freezing-point storage.