In the development of novel pharmaceutics and cell-mediated therapeutics, the immune system has to be well considered, as part of the response mechanism or as a potential collateral for drug toxicity. To reduce the attrition of such developments, the interaction of immune cells with drugs and/or with other cell types should be mechanistically investigated. As the lymph node (LN) is the integrating center for immune cells, whereby the body invokes responses against foreign substances, we have developed an artificial biomimetic LN, called LN-on-Chip, to facilitate investigations to cellular kinetics, cell-cell interactions and sampling. We recreated the biological scaffold and accurately reintroduced the cellular residents in a 3D distribution in the device. We demonstrated that the system replicates key features of the human LN, supports 3D cell culture in biomimetic matrices, and sustains cell viability for over 24 hours. The ultimate goal of this platform is to enable investigations into the effects of pharmaceutics to downstream immunology in more physiologically relevant microenvironments, thus, contributing to increased safety, lowered cost, and shorter cycles for drug development.
A magnetometer is a sensor that measures magnetic fields and uses their direction and intensity for telemetry and navigation. In this paper, a Z-axis Lorentz-force microelectromechanical (MEMS) magnetometer is introduced. The device is a resonant structure that has been designed for Q factor and resolution. The design has been modelled using Coventor?s MEMS+. A MATLAB and MEMS+ interfacing code has been utilized for design modeling and verification and to facilitate the design iteration and optimization process. The design has been shown to exhibit the desired motion in its first mode at a frequency of 668 kHz. Several parameters sweep of geometric design variables have been conducted in an effort to optimize the mechanical sensitivity of the device. The design has been fabricated using a MEMSCAP Silicon-On-Insulation (SOI) standard process and is currently undergoing testing and characterization at Khalifa University.
The built environment is expanding with the increase in population, urbanization and change in life style, all of this mostly requires concrete, the material responsible for 5% of global CO2 emissions and the second producer of greenhouse gases. Therefore, the need to create a more sustainable concrete that can accommodate the human growth without jeopardizing the environment or depleting natural resources. Utilizing waste within concrete has been researched as a double impact solution, creating a green concrete and a waste management technique. This paper reviews the utilization of agricultural waste within the concrete industry by looking at three options for integrating Agro-waste in concrete without compromising its performance. Agro-waste as coarse and/or fine aggregate, Agro-waste as partial or full replacement of Portland cement and Agro-waste as concrete fiber reinforcement. Available literature examines single application of Agro-waste, thus, compiling different approaches in one review will provide an objective and broad understanding of incorporating agricultural waste in concrete and all associated implications. Moreover, summarizing the optimal mixing percentages for each distinct application resulting in mechanical and/or thermal parity or even enhancement to conventional structural light weight concrete based on recent experimental research.
Cooling is considered one of the major energy consumers around the world. For example, air conditioning in Abu Dhabi makes up around 70% of the total electricity. Cooling process is mainly based on vapor compression refrigeration cycle and hence, to make the refrigeration cycle environmentally friendly, thermal energy storage by adsorption is a promising solution which can utilize waste heat energy for applications such as cooling, heating and many other utility applications. One of the major challenges in adsorption thermal energy storage applications is choosing the optimal working pairs (i.e. fluid and material) to obtain the most desirable and efficient adsorption system. Therefore, the objective of this project is to synthesize novel adsorptive materials (i.e. adsorbents) for cold energy storage that will give better energy storage capabilities based on waste heat energy or solar energy and thus contribute in producing an eco-friendly cooling process.
PVT properties are critical to petroleum reservoir characterization and management. This study investigates reservoir fluid phase behavior at different pressure drawdown conditions in the nearwellbore region using simulators and PVT studies. CMGs WINPROP package was used to analyze the phase behavior of the data set and generate component properties for compositional simulations using GEM. Also Eclipse PVT Package (PVTi) was used to simulate laboratory experiments in order to compare fluid samples for consistency. Four different PVT lab reports were used. WinProp was found to be more accurate in matching the laboratory results. PVTi produced unacceptably high differences. Regression was used to tune the equation of state to match experimental results in both simulators. Three of the PVT reports still had big differences between the GOR reported by the lab and the GOR calculated by the simulators both before and after regression. The calculated GORs in both simulators were comparable in both cases, so it is suspected there were errors on the PVT data. Further work with CMG reservoir simulator showed that inaccurate PVT results and/or poor sample quality could affect modeling near wellbore fluid behavior. This paper recommends best practices in using simulators to assist in validation of PVT data.
In this contribution, the soft-SAFT EoS, an equation of state based on Statistical Thermodynamics, was used to model the phase equilibria of carbon dioxide (CO2) and hydrogen sulfide (H2S) in aqueous monoethanolamine (MEA) at conditions of relevance for acid gas separation. The chemisorption of H2S in aqueous MEA was described in terms of the formation of H2Samine aggregates physically bounded by strong intermolecular association interactions, consistent with our previous works on the chemisorption of CO2. A maximum of two adjustable parameters, optimized for a fixed MEA concentration, sufficed to obtain an accurate representation of the absorption of H2S in aqueous MEA over a broad range of conditions. The developed model can predict the simultaneous absorption of H2S and CO2 in aqueous MEA solvent in good agreement with experimental literature data and comparable to those obtained from the recommended thermodynamic model (e-NRTL) available in Aspen Plus? engineering simulator. These results demonstrate the reliability of the model as a potential solvent screening tool for acid gas separation, owing to its high level of accuracy, transferability and predictive capabilities.
To meet the regulations on the emission of toxic gases such as Carbon Monoxide (CO) and Hydrogen Sulfide (H2S) from the Sulphur Recovery Units (SRUs), a high amount of fuel gas is burnt in the incinerator to oxidize them that increases the cost and CO2 emissions. BTEX are often present in the feed gas to SRU and failure to oxidize them in the furnace leads to increased emissions of toxic gases. This study investigates the role of oxygen enrichment on the emissions of CO and BTEX. The SRU simulations were conducted using plant data and a reaction mechanism. The results showed that oxygen enrichment could trigger the oxidation of BTEX and CO by the abundant SO and SO2 species in the furnace, thus assisting to decrease the emission of CO and BTEX from the furnace. This simulation results will assist in optimization of oxygen enrichment in SRU to reduce emissions.
In this research paper, we describe the design, model and test a soft-bodied, bioinspired, underwater robot that can potentially provide manipulation, locomotion and intervention in unstructured marine ecosystems and underwater industrial installations. The main innovative component of the robotic system is a flagellum-inspired elastic propulsor, composed of an electric motor connected to a propelling filament using a curved hook structure. The propulsor is capable of passively attaining a range of stable helical waves along its length due to interaction by its surrounding fluid and creating positive net thrust. This novel design provides a safe, robust and adaptable alternative to traditional rigid propellers while being suitable for locomotion as well as manipulation tasks. The complete robotics system will be equipped with high-resolution cameras and underwater sensors to achieve a safe and reliable interaction with the environment, including ship and submarine hulls, and offshore oil/gas pipeline. We investigate the relationship between actuation velocity and material elasticity, as well as the instantaneous and angular velocity of a single flagellated canister in a self-propelled test.
Machine learning-based approach is desired for accelerating materials design, development and discovery. Bayesian optimization, a trending machine learning technique, is attracting growing attention in materials science. As a first attempt to date, we propose to apply Bayesian optimization to design ultrathin multilayer spectrally selective absorber coatings for hightemperature solar power generation. The optimized design of a trilayer W-SiC nanocomposite coating achieves a total solar absorptance over 92.9% in the wide wavelength range of 250? 1750 nm. Our subsequent fabrication and experimental characterization have demonstrated the capability of the proposed approach. This closed-loop machine-learning-based approach sheds light on the autonomous discovery of materials for solar energy and sustainability applications.
As Silicon-based power devices are reaching their theoretical limit, wider bandgap materials like GaN and SiC have become the main focus for power applications, owing to their superior electrical properties such as high critical electric field and saturation drift velocity. In practice, effective edge terminations techniques, such as junction termination extension (JTE) structures, play a crucial role in realizing high-voltage devices. Though certain challenges in fabricating such devices, such as difficulty in forming p-type region in GaN, makes it difficult to realize edge termination, hence impeding the development and adoption of such devices. This work reviews the available techniques to realize such edge termination and discuss their limitations and the techniques used to overcome the shortcomings in fabricating such devices.
