STRUCTURAL CHARACTERIZATION OF PANERO CRUDE OIL BY FT-INFRARED AND 1H N.M.R. SPECTROSCOPY

ABSTRACT

The Panero crude oil from the Badin block of Sind Province in Pakistan was separated into four fractions, i.e., naphtha, kerosine, diesel oil and the residue. Each fraction has been characterized by FT-Infrared and 1H n.m.r. spectroscopy. The infrared spectroscopy has provided important insight into the functional groups present in each fraction, while the ¹H n.m.r. data was used to obtain average structural parameters.     

Software-Defined Space-Air-Ground Integrated Network Architecture with the Multi-Layer Satellite Backbone Network

Under the background of the rapid development of ground mobile communication, the advantages of high coverage, survivability, and flexibility of satellite communication provide air support to the construction of space information network. According to the requirements of the future space information communication, a software-defined Space-Air-Ground Integrated network architecture was proposed. It consisted of layered structure satellite backbone network, deep space communication network, the stratosphere communication network and the ground network. The SpaceAir-Ground Integrated network was supported by the satellite backbone network. It provided data relay for the missions such as deep space exploration and controlled the deep-space spacecraft when needed. In addition, it safeguarded the anti-destructibility of stratospheric communication and assisted the stratosphere to supplement ground network communication. In this paper, algorithm requirements of the congestion control and routing of satellite backbone protocols for heterogeneous users’ services were proposed. The algorithm requirements of distinguishing different service objects for the deep space communication and stratospheric communication network protocols were described. Considering the realistic demand for the dynamic coverage of the satellite backbone network and node cost, the multi-layer satellite backbone network architecture was constructed. On this basis, the proposed Software-defined Space-Air-Ground Integrated network architecture could be built as a large, scalable and efficient communication network that could be integrated into space, air, and ground.     

MHD convective heat transfer of nanofluids through a flexible tube with buoyancy: A study of nano-particle shape effects

This paper presents an analytical study of magnetohydrodynamics and convective heat transfer of nanofluids synthesized by three different shaped (brick, platelet and cylinder) silver (Ag) nanoparticles in water. A two-phase nanoscale formulation is adopted which is more appropriate for biophysical systems. The flow is induced by metachronal beating of cilia and the flow geometry is considered as a cylindrical tube. The analysis is carried out under the low Reynolds number and long wavelength approximations and the fluid and cilia dynamics is of the creeping type. A Lorentzian magnetic body force model is employed and magnetic induction effects are neglected. Solutions to the transformed boundary value problem are obtained via numerical integration. The influence of cilia length parameter, Hartmann (magnetic) number, heat absorption parameter, Grashof number (free convection), solid nanoparticle volume fraction, and cilia eccentricity parameter on the flow and heat transfer characteristics (including effective thermal conductivity of the nanofluid) are examined in detail. Furthermore a comparative study for different nanoparticle geometries (i.e. bricks, platelets and cylinders) is conducted. The computations show that pressure increases with enhancing the heat absorption, buoyancy force (i.e. Grashof number) and nanoparticle fraction however it reduces with increasing the magnetic field. The computations also reveal that pressure enhancement is a maximum for the platelet nano-particle case compared with the brick and cylinder nanoparticle cases. Furthermore the quantity of trapped streamlines for cylinder type nanoparticles exceeds substantially that computed for brick and platelet nanoparticles, whereas the bolus magnitude (trapped zone) for brick nanoparticles is demonstrably greater than that obtained for cylinder and platelet nanoparticles. The present model is applicable in biological and biomimetic transport phenomena exploiting magnetic nanofluids and ciliated inner tube surfaces.     

Properties and performance of orthogonal neural network in function approximation

Backpropagation neural network has been applied successfully to solving uncertain problems in many fields. However, unsolved drawbacks still exist such as the problems of local minimum, slow convergence speed, and the determination of initial weights and the number of processing elements. In this paper, we introduce a single‐layer orthogonal neural network (ONN) that is developed based on orthogonal functions. Since the processing elements are orthogonal to one another and there is no local minimum of the error function, the orthogonal neural network is able to avoid the above problems. Among the five existing orthogonal functions, Legendre polynomials and Chebyshev polynomials of the first kind have the properties of recursion and completeness. They are the most suitable to generate the neural network. Some typical examples are given to show their performance in function approximation. The results show that ONN has excellent convergence performance. Moreover, ONN is capable of approximating the mathematic model of backpropagation neural network. Therefore, it should be able to be applied to various applications that backpropagation neural network is suitable to solve. © 2001 John Wiley & Sons, Inc.     

What users really think about the usability of smartphone applications: diversity based empirical investigation

In recent years, smartphone devices are becoming progressively popular across a diverse range of users. However, user diversity creates challenges in smartphone application (app) development. The diversity of users is often ignored by designers and developers due to the absence of requirements. Owing to this, many smartphone users face usability issues. Despite that, no dedicated platform found that guide smartphone app designers and developers regarding human universality. The aim of this research is to explore the requirements of diverse users in smartphone apps and provide usability guidelines. The objectives of this research are achieved by following two scientific approaches. The human diversity requirements are located by conducting usability tests that investigated the requirements in the form of usability issues. The systematic literature review (SLR) process is followed in order to resolve the discovered usability issues. Both approaches resulted in a list of usability issues and guidelines. The usability tests returned 27 problems while the SLR came with a comprehensive set of universal usability guidelines that were grouped into eleven categories. The study concluded with some major outcomes. The results show evidence of critical usability problems that must be addressed during the design and development of smartphone apps. Moreover, the study also revealed that people with disabilities were three times severely affected by usability problems in such apps than people of different ages and their needs must be considered a top priority in the development of smartphone apps.

     

Exploration of CeO₂ nanoparticles as a chemi-sensor and photo-catalyst for environmental applications

CeO₂ nanoparticles were synthesized hydrothermally and utilized as redox mediator for the fabrication of efficient ethanol chemi-sensor. The developed chemi-sensor showed an excellent performance for electrocatalytic oxidization of ethanol by exhibiting higher sensitivity (0.92 μA?cm^− 2?mM^− 1) and lower limit of detection (0.124 ± 0.010 mM) with the linear dynamic range of 0.17 mM-0.17 M. CeO₂ nanoparticles have been characterized by field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), Raman spectrum, Fourier transform infrared spectroscopy (FTIR), and UV-visible absorption spectrum which revealed that the synthesized CeO₂ is an aggregated form of optically active spherical nanoparticles with the range of 15-36 nm (average size of ~ 25 ±10 nm) and possessing well crystalline cubic phase. Additionally, CeO₂ performed well as a photo-catalyst by degrading amido black and acridine orange.     

Sulfide-induced nitrate reduction in the sludge of an anaerobic digester of a zero-discharge recirculating mariculture system

The anaerobic digester is a vital component in a zero-discharge mariculture system as therein most of the organic matter is mineralized and nitrogen-containing compounds are converted to gaseous N₂. Although denitrification is a major respiratory process in this nitrate-rich treatment stage, also sulfate respiration takes place and may cause undesirable high sulfide concentrations in the effluent water. To examine the effect of sulfide on nitrate reduction, in situ depth profiles of inorganic nitrogen and sulfur compounds were determined. Additionally, nitrate reduction was examined as a function of ambient sulfide concentrations in sludge collected from different locations in the anaerobic reactor. Depth profiles showed high concentrations of nitrate and low concentrations of sulfide and ammonia in the aqueous layer of the reactor. A sharp decrease of nitrate and an increase in sulfide and ammonia concentrations was measured at the water-sludge interface. Nitrate reduction was highest in this interface zone with rates of up to 8.05 ± 0.57 μmol NO₃⁻ h⁻¹ g_(sludge)⁻¹. Addition of sulfide increased the nitrate reduction rate at all sludge depths, pointing to the important role of autotrophic denitrification in the anaerobic reactor. Dissimilatory nitrate reduction to ammonia (DNRA) was found to be low in all sludge layers but was enhanced when sludge was incubated at high sulfide concentrations. Although nitrate reduction rates increased as a result of sulfide addition to sludge samples, no differences in nitrate reduction rates were observed between the samples incubated with different initial sulfide concentrations. This as opposed to sulfide oxidation rates, which followed Michaelis-Menten enzymatic kinetics. Partial oxidation of sulfide to elemental sulfur instead of a complete oxidation to sulfate, could explain the observed patterns of nitrate reduction and sulfide oxidation in sludge incubated with different initial sulfide concentrations.     

Profiling expression patterns and isolating differentially expressed genes by cDNA microarray system with colorimetry detection

A high-density cDNA microarray with colorimetry detection system to simultaneously monitor the expression of many genes on nylon membrane is described and characterized. To quantify the expression of genes and to isolate differentially expressed genes, the southern hybridization process on filter membranes was employed. The levels of gene expression were represented by color intensities generated by colorimetric reactions in place of hazardous radioisotopes or costly laser-induced fluorescence detection. The gene expression patterns on nylon membranes were digitized by devices such as an economical flatbed scanner or a digital camera. The quantitative information of gene expression was retrieved by image analysis software. Quantitative comparison of the northern dot-blotting method with the microarray system is described. Applications employing single-color detection as well as dual-color detection to isolate differentially expressed genes among thousands of genes are demonstrated.     

Individual differences in the stress-response-dampening effect of alcohol: A dose-response study.

Recent evidence suggests that alcohol consumption can lead to attenuated stress response, but parameters such as dose and personality traits appear to influence the magnitude of alcohol's effects. To better characterize these relations, 96 21–30 yr old male social drinkers were assigned to either a placebo, a moderate, or a high dose of alcohol and then had heart rate and a self-report measure of anxiety taken during a stressful social interaction. Consistent with previous research, alcohol dampened both heart rate and, to a lesser extent, anxiety responses to the stressor. Because the reduced heart rate responsivity was obtained in the absence of increased basal heart rate, it is suggested that cardiovascular stress response dampening (SRD) does not appear to be an artifact of an initial values effect. Although there was some evidence that Ss with prealcoholic personality traits were especially sensitive to the SRD effect of alcohol, this effect did not appear to be strong or robust across alternative measures of prealcoholic traits. There was no evidence that self-consciousness or expectancies for tension-reducing alcohol effects were associated with stress responsivity in Ss consuming alcohol. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)