Membrane technology, which has such promising features as high efficiency, low-cost and easiness to scale-up, has gained more and more attention in R&D. Its rapid progress urgently needs new technologies of membrane characterization and evaluation for both gas and liquid applications. This work reports a reverse selective anomaly regarding membrane separation for binary gas mixtures. It is mainly ascribed that adsorption-diffusion mechanism of the carbon membranes makes it a possible for larger diameter molecules to surpass the flux of smaller ones. This research laid solid fundamental for development of membrane technology
This work aims to study the effect of ionic liquid 1-Butyl-1-methylpyrroldinum chloride as an entrainer in the azeotropic distillation of water+ 2-Propanol. Up until today, many ionic liquids have been used to eliminate azeotropes in various systems, but few IL's have been studied with the water/isopropanol azeotrope. Most investigated ionic liquids are Imidazolium based. In this work, the studied ionic liquid is pyrrolidinium based. Vapor liquid equilibrium (VLE) data has been collected, and modelled with the Non-Random, Two-Liquid model (NRTL).
Alkanolamine systems are an integral part of Natural Gas plants. Which scrub H2S and CO2 from crude gas. Reactions between acidic contaminants and amine can produce thermally stable salts, called Heat Stable Salts (HSS). Since the technology is closed loop, these salts can accumulate overtime and can cause major operational problems in alkanolamine systems such as corrosion, foaming and reduced solvent efficiency. The current technologies available to treat and remove heat stable salts are inefficient and can lead to huge amine losses. Capacitive Deionization is an alternative technology for desalination that can be also applied to Lean Amine systems to remove HSS. In this research, a number of different carbon electrodes were prepared and tested in order to determine the most suitable one for HSS removal. Different biochars were also prepared, biochar prepared from Date Palm gave the highest removal. The Date Palm Activated carbon was characterized by XRD, SEM and Elemental Analysis. It was found that activated Biochar (or Activated Carbon) from Date Palm (DPAC550) gave the best results with 29% removal efficiency compared to all the other carbon electrodes that were tested. The surface area was found to be of 1659.484 m?/g, and the carbon was rich with CO groups. Pseudo-first order model best represented the electrosorption of HSS by DPAC550.
Algae cultivation has been verified as means of CO2 utilization that can result in carbon footprint reduction. Hence, this paper presents an integrated modeling of algae cultivation for bio-fixation. This bio-mathematical framework, which incorporates the extracellular model of typical microbial culture with the genome-scale metabolic reconstruction via dynamic flux balance analysis (DFBA), was presented here and employed to evaluate the performance of algae pond as agents of carbon capture under the prevailing conditions of arid environments. The results show that any further increase in the CO2 fraction of the flue gas beyond 5mol% will lead to a decline in the amount of carbon utilized while the CO2 emission increases. The model can serve as a valuable tool in the designing of flue gas-based microalgae cultivation systems in the United Arab Emirates.
In this work, the abundant availability of elemental sulfur from oil and gas industries in the United Arab Emirates (UAE) was used to prepare sulfur copolymers via inverse vulcanization reaction. Elemental sulfur was reacted with cyclic monomers with different ring size (seven or eight membered ring) containing one or more double bonds. The structural property of the sulfur copolymers with respect to the ring size and the number of double bonds was established using DSC and TGA. The thermal properties like Tg and thermal degradation was found to increase with increasing in the ring size and number of double bond. The proton 1H NMR technique confirmed completion of crosslinking reaction. XRD reveals the conversion of crystalline sulfur into amorphous copolymer after cross-linking reaction. The prepared sulfur copolymers showed lowest thermal conductivity which can be used as an efficient insulators.
As the friction and wear properties of a material are very much influenced by the tribological variables, a testing system is used which permits the use of a wide range of test speeds, loads conditions on coatings. In our previous work, the thermal spray (NiAl2O3) with inclusions of solid lubricants (Graphite) coats were developed on Bakelite and the condition of the coatings were evaluated for different wear rate against abrasive, erosive and adhesive wear. Erosive wear tester was used to study the wear rates for 30?, 60?, and 90? impingement angle on the substrate at RT and 160 ?C and the results showed that maximum wear rate was observed at 30? and at elevated temperatures. This research shows the impact of reciprocating load on the coats and the study of wear rates. Reciprocating scratch tester Taber 5900, was used to estimate the wear rate of coated Bakelite. Normal load of 1N, 2N, 2.5N, & 3N with varying reciprocating speed of 20, 50, 55 and 70 cycles per minute were the test conditions observed. Keeping the stroke length constant, wear rate was observed on thermal coatings and the tests show that NiAl2O3 was thermally and tribologically stable.
Carbon steel pipelines are renowned for their long-term resistance to the hydrostatic pressure of the transported fluid. Nevertheless, failure of carbon steel pipes due to corrosion can be catastrophic if not predicted or mitigated properly. The corrosion on pipeline walls will lead to severe loss of material and eventually cause complete loss of pipeline integrity. This study will assess the burst pressure of predefined internally corroded API carbon steel pipelines through finite element analysis (FEA). The mechanical response of the host carbon steel pipeline is empirically estimated. A set of corrosion defect geometrical sizes, such as depth, width, and length to be considered is carefully developed. Based on the parametric FEA results of corrosion-defected carbon steel pipelines, the Buckingham Pi-theorem modelling approach was used to derive an analytical closed-form expression. The establishment of this functional dependence will permit direct substitution of parameters to assess the defected pipe integrity.
Corrugated core sandwich panels are used extensively in the engineering field. To understand the behavior of the corrugated materials and identify their properties, these materials are investigated to establish their behavior pattern. One approach is to model the material and investigate the behavior under different loadings. To ease the modeling of a corrugated material, it has to go through a homogenization process to reduce the computational time needed. A homogenization method is derived for an arc-tan corrugation including the face sheets. The derivation is based on Castigliano's second theory. The model derived is only for the elastic modulus in x1 direction (E1), which is one of five properties that defines the orthotropic corrugated core sheets. The theoretical model derived is then compared to models found in the literature for validation.
The paper investigates the possibility to inspect the weld quality from the voltage and sound signals. The voltage and sound data recorded while welding are analyzed for their behavior during arc instability. The result reveals that the sample points in the standard deviation or mean control chart scatter beyond the control limits for an unstable process at the disturbed region whereas they lie within the control limits for all stable process. The frequency spectrum of the welding sound proved to have peak power at 216 Hz consistently for the quality welds. Noise at higher frequencies is observed in the unstable welds. The two techniques are highly adaptable for monitoring of the weld quality.
Advantages offered through eddy current technology delivers a promising solution to assess metallic coating thicknesses over nonmagnetic metals. Current single and multi-frequency impedance based methods are sensitive to different coating/substrate combinations as well as liftoff deviations from those used over the calibration blocks. With its frequency-dependent penetration depth, eddy current technology lends itself to asses such structures. Existing apparent eddy current conductivity (AECC) models are limited to smooth conductivity profiles. It was only until recently that a new AECC-based inversion algorithm was developed to capture the AECC spectrum of rectangular conductivity profiles at ?25.4 ?m lift-off range [1]. This technique provided a one order of magnitude improvement in estimating coating thicknesses when compared to existing impedance-based models. However, drawbacks such as the requirement of a large coil diameter to meet the plane-wave approximation, numerous calibration blocks and a time consuming frequency sweep made this technique unpractical. Building on this algorithm's capabilities a new AECC-based inversion algorithm has been developed which takes measurements at a single frequency which helps in eliminating the limitations offered by the previous algorithm [2]. This work assesses 0.5mm Ti-6Al-4V (?c = 1.05 %IACS) coating over SS304 (?s = 2.40 %IACS) substrate using COMSOL to obtain its AECC spectrum, from which the optimum frequency is obtained where the rate of AECC change is maximum. This frequency is further tuned based on AECC change sensitivity to coating thickness variations using the plane-wave approximation. Finally, the model is validated for single-frequency AECC measurement using different coating thicknesses relevant to the industry.
