This study has been conducted to assess the newly released PPP guidelines of the UAE (2017) and compare them with two international guidelines - selected based on date of release and level of development - which are the United Nations guidelines for local governments and the European commission guidelines; the study is based on comparison by two methods: ? Plus/delta Analysis ? Significance comparative analysis The results show that the UAE guidelines have great potentials but still require some improvements in some points; some suggestions for the improvements have been given in the plus/delta analysis while in the significance analysis these points were assessed and quantified. In summary, while detail amount in the UAE guidelines is beneficial, they don't have to be listed in the way they are. Mainly, if most of the steps are revised and summarized, and if the sequencing is modified, the UAE guidelines could be more reliable.
A non-parametric PID tuning approach for a Magnetic Levitation System (MLS) is proposed in this paper. The proposed tuning method is non-iterative and is based on a test involving the two-relay controller that provides identification at frequencies higher than the phase cross over frequency of the process. The tuning procedure has two consecutive stages. First, generating self-excited oscillations in the closed loop of the MLS using the two-relay controller test, and measuring the ultimate frequency and ultimate amplitude of the generated oscillations. Second, using the results obtained from the test and certain non-parametric tuning rules, the parameters of the PID controller are determined. The tuning rules that are produced and used guarantee the specified gain margin. We validate the approach using the Inteco MLS experimental setup. The simulations and the experimental results show the effectiveness of the proposed approach.
Applying Renewable energy (RE) resources can reduce the power shortages demand along with reducing the power consumption which leads to reduce the GHG emissions. RE is an essential part of the green initiatives market and defined as the important physical infrastructure schemes that reinforce the development of zero carbon society. Climate change alarmed and motivated efforts to rise the share of a power generation from RE. This paper will focus on determining the potential of establishing a large-scale RE project in Fujairah, UAE. It explores the technical and economic aspects of launching large-scale solar plants and wind farms in the region. The paper outcomes are expected to identify the necessary tools and critical success factors (CSF) needed to enable the different energy stakeholders to make cost-effective decisions. Similarly, it will deliver the best technical and economic implementation plans taking into consideration the necessary upgrade for the current policies and regulations.
This paper will discuss techniques for attitude determination and control in small satellite at the low earth orbit. Investigating optimal solutions for attitude control is essential for regulating the maneuvers of the spacecraft in order to point to a certain location or track an object. This can be a challenge due to the presence of uncertainties and external torques that has not been accounted for. The paper will discuss a solution for spacecraft attitude determination and control.
During the past decades, an increasing interest in passive Targeted Energy Transfer (TET) for vibration mitigation and energy harvesting purposes has been observed. Therefore, extensive investigations for employing nonlinearly coupled dynamical attachments known as nonlinear energy sinks (NESs) with primary linear structures have been conducted in different related engineering applications. Due to their nonlinear coupling, NESs are capable of performing rapid, passive and nearly irreversible TET from the linear primary system for a broadband energyfrequency domain through single or cascade of resonance captures. To this end, many types of NESs which have been categorized according to their nonlinear coupling element and force were extensively investigated via analytical, numerical and experimental techniques.
Composite structures are cured in the autoclave under high temperature cycle that introduces thermal residual stresses which remain in the structure after it cools down. They rise as a result of temperature variation within the part due to different factors such as the anisotropy nature of the composite material, tool and part interaction, etc. The relaxation of residual stresses leads to spring in/back in curved structures and warpage in flat structures. This paper discusses the variation in temperature responses, degree of cure and cure rate of a flat composite structure that includes different design features, e.g. core ramp and monolithic area with variant thicknesses, using COMPRO thermochemical analysis run. Simulation and experimental results showed good correlation which allowed for further investigation of the uneven cure rates across the panel, obtained by simulation, that led to the rise of thermal stresses causing warpage in the panel.
Innovative aerodynamic technologies will play a key role in improving the next-generation aircraft's performance. Active flow control using the Sweeping Jet (SWJ) actuators is one of the most promising technologies to solve critical problems of aerospace industry such as drag and weight reduction, flow separation, and noise. Initial applications showed that SWJ actuator has the advantage of having no moving parts, robustness and reliability, manufacturability and ease of system integration. However, a lack of knowledge continues regarding the actuator's properties, underlying physical flow mechanisms, and governing parameters for flow control applications. The main objective of this paper is to understand internal flow physics, jet oscillation process, and pressure drop mechanism using Two-Dimensional-Unsteady Reynolds-Averaged-Navier-Stokes simulations. This understanding will help to the development of design methodologies for the sweeping jet with minimum pressure losses, controllable sweeping frequency, and a more efficient flow control actuator for required conditions. The design rules and scaling laws may increase not only the technology readiness level (TRL) but also manufacture readiness level (MRL) by two folds.
Conventional treatment for cancer has many side effects which limited its use. This augments the need for new smart drug delivery systems, which are nanocarriers that can shield the healthy cells from the adverse side effects of chemotherapy and enhance the drug's pharmacokinetics. One type of biodegradable nanocarriers are liposomes. Once these drug loaded liposomes reach the tumor, their release can be triggered using ultrasound, an external modality capable of accelerating the cytotoxic effects of the drug and subsequent accumulation inside tumor cells. The purpose of this study is to test the ultrasound-triggered release and cellular uptake of immunoliposomes that have increased affinity toward breast cancer cells. Proteins attached on the surface of the liposomes will guide them to the tumor that overexpresses receptors for that protein. Frist the attachment is confirmed, then ultrasound triggered release is studied.
Superabsorbent hydrogels are the hydrogels that can absorb and retain huge amount of water. Acrylic acid is the most frequently used chemical in preparing superabsorbent hydrogels. The swelling properties of poly acrylic acid hydrogels (commercial hydrogels) were investigated and developed in many published works. In this study, the effects of the environmental factors on the absorbency of commercial hydrogels have been examined using two-level factorial design. These factors include the amount of applied hydrogel, swelling time, pH and temperature. It has been found that the absorbency increases with the swelling time and the temperature. On the other hand, it decreases as the amount of hydrogel or the pH increases.
Advancements in post combustion carbon capture through solvent based absorption process require extensive development and screening of a new combination of solvents which can address the drawbacks inherent in amine based absorption systems. Amine based deep eutectic solvents (DES) have emerged as promising solvents to tackle some of the issues associated with amine absorption systems, whilst maintaining the important qualities and benefits of amines. In this study, the effect of different parameters on the CO2 absorption capacity of 105 amine based deep eutectic solvents has been determined with conductor like screening model for real solvents (COSMO RS). The amine DESs utilized for this study consists of different combinations of hydrogen bond donors (HBD), salt anion, salt cation and salt-to-HBD molar ratio. The effect of temperature and gas pressure on the CO2 absorption capacity for the amine based DESs was studied. Results showed that the pressure has a linearly increasing nature on the solubility of CO2 in the amine based DESs.
