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Empirical results of turboexpander process, which used simulation to extract natural gas liquid from natural gas compositions, are presented.

Annexin A1 (ANXA1) is an important anti-inflammatory mediator that may play a significant role in bronchial asthma. MiR-196a2 can target ANXA1 and therefore may play a role in the pathogenesis of asthma.

The objective of this work was to upgrade bio-oil from bagasse by pyrolysis using catalyst/biomass of three different compositions (5, 15 and 20 wt% HZSM-5 loadings). The thermal analysis and product distribution experiments were carried out in a thermogravimetric analyzer (TGA) and a fixed bed reactor, respectively. In TGA, the pyrolysis of catalytic runs shifted the thermograph curves to the lower temperatures and generated high yield residues compared to that obtained from non-catalytic run. From a fixed-bed condition, the maximum bio-oil yield from non-catalytic and catalytic runs at a temperature of 500 °C at 15% ZSM-5 catalyst concentration were 49.4% and 21.1 wt% respectively. Aromatics, phenols and oleic acids are the main chemical components deduced from gas chromatography/mass spectrometry (GC–MS) analysis of the bio-oil. Bio-oil from catalytic pyrolysis had more aromatics (desirable component) and less oleic acid (undesirable component) than the bio-oil from non-catalytic pyrolysis. The study of bio-oil from catalytic bagasse pyrolysis enhances desirable component when used as transportation fuel. Besides addition of catalyst improving the degradation mechanism of biomass also alters the product composition closer to the aromatic range hydrocarbon.

The corrosion inhibition effect of some anionic surfactants (Diisononyl phthalate (A), N-oleyl-1, 3-propane –diamine (B), and Sodium lauryl sulphate (C)) on the corrosion of carbon steel in 1M hydrochloric acid solution were studied by chemical method (weight loss) and electrochemical methods (potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). From the results, it was clear that these surfactants are good inhibitors for corrosion of carbon steel in 1M HCl solution. Their inhibition depends mainly on their concentrations and temperature of solution. Polarization data revealed that these surfactants act as mixed type inhibitors. The surfactants adsorptions were found to follow Langmuir’s adsorption isotherm. The thermodynamic parameters of activation and adsorption were calculated and discussed. Adsorption of used surfactants led to a reduction in the double layer capacitance (Cdl) and an increase in the charge transfer resistance (Rct). All measurements used confirmed the adsorption of the surfactants used on carbon steel surface. Confirmation of these various independent techniques proved validity of the obtained data.

The oil and gas industry struggles to prevent formation of hydrates in pipeline by spending substantial amount of dollars. Hydrates are ice-like crystalline compounds that are composed of water and gas in which the gas molecules are trapped in water cavities. The hydrate formation is favorable at elevated pressure and reduced temperature and can be determined through experiment. However, the cost involved to determine early hydrate formation using experiment is driving researchers to seek for robust prediction methods using statistical and analytical methods. Main aim of the present study is to investigate applicability of radial basis function networks and support vector machines to hydrate formation conditions prediction. The data needed for modeling was taken from well-established literature. Performance of the models was assessed based on MSE, MAE, MAPE, MSPE, and Modified Pearson’s Correlation Coefficient. Data-based models enable the oil industry to predict the conditions leading to hydrate formation hence preventing clogging of the pipeline and high pressure buildup that could lead to sudden burst at the connections.

Advancing of micro-milling process via ultrasonic vibration assist has been proven able to improve machining characteristics such as surface roughness quality and dimension accuracy. The improvement is due to the cutting motion of Vibration Assisted Machining (VAM) process. Thus, for every vibration motion manner, the cutting characteristic of the VAM system will be difference from one to another. This paper presents the development approach of ultrasonic vibration assisted micro-milling (UVAM) using tilted 45° XY stage. It covers theoretical perspective and the influence of Minimum Quantity Lubrication (MQL) system as cutting fluid. It will emphasize on the theory of surface roughness, dimension tolerance and cutting tool life. Piezo-actuator is used as fast servo vibration mechanism in specific axis input with controlled signal. The input signal is sine wave with controllable frequency and amplitude to allow mechanism control algorithms to be develop during the process. In addition, the effect of cutting fluid was be analyzed to understand the potential capabilities of this aid on UVAM process.

Roller burnishing process was applied to Al2O3/A356 composite specimens. The process was carried out on vertical milling machine. Effects of the burnishing process with varying process parameters on the characteristics of the machined surface and sub-surfaces were investigated. Residual stress distribution at different depths beneath the burnished surfaces, microhardness distribution, surface roughness were used as criteria to obtain the optimum burnishing conditions that give burnished surfaces with high integrity for the Al2O3/A356 composite. Results showed an improvement in surface characteristics of Al2O3/A356 composites using burnishing process. The better surface roughness was obtained with double passes burnishing, depth of penetration of 0.12 mm, and burnishing speed of 72 mm/min. Increase of number of burnishing passes increases the value of residual compressive stress and the microhardness at the burnished surface and subsurface. The microhardness slightly decreased with the increase of burnishing speed.

Certain radioactive isotopes decay by emitting positrons, and the positrons can be used to probe the structure of solid materials. For example, one can investigate the grain size due to deformation in a metal. XRD is also a powerful technique for detection the defects introduced into a metal and for investigating the microstructure of a deformed metal. In this paper we shall investigate the plastic deformation effect on the grain size of 5251 Al alloys using two different techniques, PALT and XRD. The study shows a significant effect of the plastic deformation on the grain size which decreases as the deformation increases.

Electrical techniques have been used to study the thermal vacancies in 401.0 casting aluminum alloy. Quenching experiments were usually performed on thin specimens to ensure a uniform quenching rate throughout the specimen. After grinding, polishing and etching, samples of 401.0 were homogenized for 12h at 673K and annealed for 90min., before quenched in water (277K) and then subjected to electrical measurements. From such measurements it is possible to deduce the vacancy formation enthalpy, which in combination with the results of self-diffusion measurements, give a value for the migration enthalpy of the vacancy.

The result of positron lifetime measurements of a defected 5251 Al alloy is reported. Positron lifetime is measured as a function of the thickness reduction of the sample which shows a nearly linear increase and then becomes constant; which can be considered to be a reason for the defect movement saturation. The trapping rate, trapping efficiency, trapping cross-section, defect concentration and defect density of positrons are also measured for the sample concerned. The behaviors of these parameters are matched with theoretical calculations. Data are analyzed using the PATFIT88 computer program.

CH4 and CO2 are greenhouse gases. Hence, their emission to the atmosphere must be controlled to avoid the global warming. Dry reforming of methane could provide a valuable tool in alleviating this problem as well as producing synthesis gas. This process is hampered by rapid catalyst deactivation due to carbon deposition and sintering of both the support and active metal. The presented study focuses on the experimental investigation the effect of addition of Calcium promoter to 1%Ni catalysts supported on a mixed 80%α-Al2O3 and 20%TiO2-P25 support. The performance of the developed catalyst was quantified by determining CH4 and CO2 conversions, synthesis gas ratio (H2/CO) and stability. Spent and fresh catalysts were characterized by TGA, SEM and EDS. Time on stream stability tests of the promoted catalyst showed that addition of limited amounts of Ca promoter would reduce carbon formation.

Lead sulfide (PbS) thin films were prepared by thermal evaporation onto glass substrates from PbS powder. The structure and DC electrical properties of evaporated PbS thin film sandwich structures with thicknesses (d) up to 600 nm have been investigated. X-ray diffraction studies showed that the films were crystalline, with a preferred orientation in the [111] direction. Capacitance measurements indicated that the films had a relative permittivity of 5.7. Room-temperature current density-voltage (J–V) characteristics revealed ohmic conduction below a transition voltage (Vt) and a power–law dependence with an exponent of ≈ 2 at higher voltages. This behaviour was interpreted in terms of space–charge limited conductivity controlled by an exponential distribution of traps below the conduction band edge. Further evidence for this conduction process was provided by a linear dependence of Vt upon d2. Analysis of the results yielded a room temperature electron concentration no of ≈ (3.9 – 5.4) x 109 m-3.

Previous work identified the kind of Jocobi polynomials suitable to solve boundary value problems of the diffusion type in a slab, cylinder or sphere. In this paper we identify the general form of boundary value problems for which Jacobi orthogonal polynomials are optimal when they are used within the framework of the method of orthogonal collocation.

An efficient numerical method for the solution of the transient heat conduction problem is developed using the orthogonal collocation method. The method is based on dividing the domain of temperature change into two zones; a zone for which the temperature profile is steep and a zone with no temperature change. As time increases the inactive zone disappears and a modified collocation method is used.

A one-point collocation scheme is developed for the transient heat conduction problem. The scheme makes use of the asymptotic solution of the problem for short time and the fact that initially the temperature profile can be divided into two zones, a fast temperature changing zone and inactive zone. For long time a Biot number dependent collocation point is used. The method provides approximate solutions which compares well with the numerical solution and other approximate solutions.

New data on blood groups among Egyptians (Dakahlya province) are obtained by studying eight blood group systems: ABO, Rhesus, MNSs, Kell, Duffy, Kidd, P and Lewis. Comparing our results with the data reported in neighbouring countries, we found in Egypt a high frequency of B, NS, cDe and K genes, a moderately high frequency of P and the presence of Fy gene. The Egyptian population appears as a mixture of African, Asiatic and Arabian characteristics.

Knowledge of the dynamical behaviour of many processes can assist in controlling plant efficiently in terms of power consumption and product quality. Binary test signals are used in the identification of electrical resistance furnaces which occur in many branches of manufacturing industry. Starting from a classification of test signals, the paper discusses the detail and special significance of binary sequences in process identification. The software involved in a microprocessor based instrument, which is designed to produce a wide range of binary test signals, is described. Both pseudo-random and multi-frequency binary Sequences may be generated. Keyboard entry is an essential menu driven option and the choice of available multi-frequency binary sequences includes Van den Bos, Harris, Lodz and recently discovered Strathclyde base-band sequences. The use of assembler generated binary test signals permits wide flexibility of device function with minimum processing time from one hardware structure.

Purpose. This study evaluated the effect of three different thicknesses of base metal resin-bonded retainers on retention/resistance. Material and methods. Three ivorine teeth, a central incisor, lateral incisor, and canine, were prepared to receive resin bonded retainers. Fifteen metal replicas of prepared teeth were made (five for each tooth morphotype). A total of 45 metal retainers were cast in three different thicknesses, 0.3, 0.5, and 0.7 mm, with 15 for each thickness. Retainers were cemented to metal die replicas with Panavia EX luting agent. After 24 hours, forces to dislodge the retainers were applied at 45 degrees to the vertical mesiodistal plane at the proximolingual line angle. Results. An increase in thicknesses resulted in elevation of dislodging forces that were almost linear for the three thicknesses of canine retainers. The central incisor exhibited the greatest increase in resistance to dislodgment between retainers that were 0.3 and 0.5 mm thick, whereas increased thickness for the lateral incisor retainer resulted in minimal or no benefit. (J Prosthet Dent 1997;78:281-5.)