Conference Papers

D1SA1: Electrical & Electronic Engineering

Converter for Energy Harvesting Start-up Systems

Maisam Wahbah (Khalifa University, UAE); Mohammad Alhawari (Khalifa University of Science, Technology and Research, UAE); Baker Mohammad (Khalifa University, UAE); Hani Saleh (Khalifa University of Sciente, Technology & Research, UAE); Mohammed Ismail (Khalifa University, UAE)

Abstract

This paper presents optimized AC-DC converters designed in 65 nm low power process. Two AC-DC converters have been designed: Bias-Flip rectifier and Voltage Doubler. The design is part of a piezo electric harvesting system targeting wearable electronics. Voltage doubler and full-bridge rectifier are fabricated to support start-up mechanism where no control circuit is required, while the bias-flip rectifier supports higher efficiency for normal operation mode. Experimental results revealed that voltage doubler is more efficient than full-bridge rectifier by 71%. The experiment uses MIDE piezo electric harvester with 25 Hz resonance frequency. However, the harvester was used at 4.5 Hz (human frequency) which degrade the energy extracted from the harvester. If another harvester was designed to tune to lower frequency, higher energy level can be extracted. The combined bias-flip rectifier and voltage doubler support energy autonomous system where no start-up power is needed.

Novel PI Controllers Tuning for a Grid-Connected Voltage Source Converter

Wesam Taha and Abdul Rahiman Beig (The Petroleum Institute, UAE); Igor Boiko (Petrolum Institute, UAE)

Abstract

Tuning approach stands as a critical issue when dealing with the voltage oriented control (VOC) topology as it ultimately defines the system performance. This paper proposes a systematic PI-tuning approach for a grid-connected voltage source converter (VSC) system. The approach involves an analytic solution based on the approximation of the plant dynamics by first-order-plus-time-delay (FOPTD) models. It is demonstrated that the system performance using the analytic tuning formulas is similar to that of the optimal ones and yield a robust system against disturbances. Therefore, analytic PI-controller tuning rules which yield optimal disturbance rejection, in terms of system parameters, can be formulated.

A 1-V 8-Bit Low-Power Clock Gated SAR ADC for Biomedical Applications

Tasnim Nazzal and Soliman Mahmoud (University of Sharjah, UAE)

Abstract

In this paper, a 1-V 8-bit 10KS/s low-power clock gated successive approximation register (SAR) analog-to-digital converter (ADC) is implemented for biomedical (lowfrequency) applications. It is based on gating the clock signal in the SAR controller logic when there is no data switching activity. Therefore, any redundant transitions will be avoided which reduce the power consumption. The proposed SAR ADC are simulated on LT Spice IV using 90nm CMOS technolgy. According to the simulation results, the proposed SAR ADC consumes 0.84 uW from 1V power supply. It has signal-to-noise ratio (SNR) of 56.2 dB, peak spurious-free dynamic range (SFDR) of 49.5 dB, and a signal-to-noise-and distortion ratio (SNDR) of 46.2 dB for a 250Hz full scale input sine wave. In addition to that, the SAR ADC has effective number of bits (ENOB) of 7.3-bits, and a figure of merit (FOM) of 0.53 pJ/Conversion step

Fifth Order Dual-Notch Low Pass Filter Oriented to EEG Detection System

Aisha Alhammadi and Soliman Mahmoud (University of Sharjah, UAE)

Abstract

This paper presents the design of fifth order dual-notch low pass filter for Electroencephalogram (EEG) detection system. The proposed filter stems from doubly terminated LC ladder network where inductors and resistors are emulated using digitally programmable operational transconductance amplifiers (OTAs). This filter is utilized to diminish the effect of power line interference at 50Hz. Also, it cuts out frequencies beyond 100Hz, which works as low pass filter for EEG systems. The transconductance value of OTA is fixed at 3nA/V for designing both inductors and resistors. PSpice results using 0.25?m CMOS process operating under +/-0.8V voltage supply are given. The dual-notch low pass filter provides total harmonic distortion (THD) of 1.17% for 20?Vpp at 100Hz sinusoidal input, input referred noise density of 36.971?V/sqrt(Hz) at the passband frequencies, total standby power consumption of 28.583?W, and notch depth of 45.631dB attenuation at 52Hz and 62.727dB attenuation at 112Hz.

The impact of Emirati household occupants on energy consumption; exploratory investigation

Amna Moh'd Al Gabshi Al Ameri and Kheira Anissa Tabet Aoul (UAEU, UAE)

Abstract

This paper reports on an exploratory qualitative study that aims to investigate nationals' behavior and its impact on energy consumption in their detached houses (villa) in Al Ain city (Abu Dhabi Emirate). The methodology is based on semi-structured interviews, addressing occupants' daily energy usage patterns, cultural aspects and their awareness level of energy consumption in their homes. Housing data and electricity bills have been considered. A pilot study with a small number of units was run first and the main investigation was carried out in 20 units. This paper presents preliminary results of this investigation, where the expected findings will contribute to a better understanding of Emirati energy consumption patterns in relation to their culture, way of life and behavior and potentially open appropriate venues to address energy use reduction in the UAE residential sector.

D1SB1: Energy & Petroleum

Simulating Fracture Initiation and Propagation of Preexisting Cracks in Rocks Subject to Internal Hydraulic Pressure and Vertical Stress

Oraib Al-ketan (Masdar ;;;;nstitute of Science and Technology, UAE); Rashid Abu Al- Rub (Masdar Institute of Science and Technology, UAE)

Abstract

This study highlights the effect of varying the hydraulic pressure inside pre-existing cracks on new-crack evolution for several geometrical crack arrangements using coupled elasto-plastic-damage model. The model contains two damage evolution laws, and uses a yield criterion that accounts for the distinct tensile and compressive behavior of rocks. Results show that the ratio of internal hydraulic pressure (HP) to the vertical load (VL) (i.e., HP/VL) affects both initiation sites and patterns of the newly propagated cracks. Both the absolute value of HP and VL affect the size, extent of newly formed cracks, and whether coalescence will occur or not. Both initial crack inclination and bridge angles affect the mechanism of crack coalescence for a certain HP/VL ratio.

Reflection Seismic Data Processing of the Offshore United Arab Emirates: Unveil the Underground Mysteries

Yi Guo, Mohammed Ali and Muhammad Tanveer (The Petroleum Institute, UAE)

Abstract

The first deep seismic study was conducted in the offshore United Arab Emirates, aiming to understand the collision tectonics and ophiolite emplacement mechanism. However, unwanted noise and multiples cover the real appearance of the underground structure. Seismic processing can increase the confidence to use the data for subsequent processing and interpretation. With an effective processing sequence, five seismic lines in northern Fujairah area were processed. Final PSTM stacks indicate some impressive structures.

Understanding the Complexities of Thick Carbonates Capillary Pressure Transition Zones is a key to Recovery Optimization

Abdessamia Jebbouri (The Petroleum Institute, UAE); Hadi Belhaj (Hadi Belhaj, UAE)

Abstract

The aim of this work is supposed to highlight the understanding of the effect of the different rock types of the addressed transition zone of the carbonate reservoir on fluids saturation distribution and to be later used for reservoir modeling and to help in optimization IOR techniques.

Optimization of Multilateral Well Productivity in Carbonate Reservoirs

Temitope Ajayi and Mohamed Hossni (THE PETROLEUM INSTITUTE ABU DHABI, UAE)

Abstract

The merits of the application of multilateral wells are well documented in the literature however, an understanding of the best operating conditions for the use of multilateral wells is rare thus we answer cogent questions related to the optimization of multilateral wells under different reservoir conditions and well design parameters. Design of Experiment (DOE) and Response Surface Methodology (RSM) was utilized. Selected factors to be optimized were chosen based on literature search, perceptions and deliberations while the objective functions are the cumulative oil production and water cut. Several experiments were conducted using three dimensional numerical simulations and the Box-Behnken RSM was used to derive the response surfaces. Single effects and interaction plots are made to show the interactions between parameters and the effect of these parameters and interactions on the objective function. This study provides a template for decision making in field development operations thereby reducing uncertainties and maximizing gains.

D1SC1: Humanities and Social Sciences

The impact of classroom density on teachers' performance& students' achievement in Al-Ain schools

Saif Alamnei (UAE, UAE); Sultan Alsuwaidi (UAEU, UAE)

Abstract

This research study aimed to investigate the students' and teachers' perceptions about the impact of classroom density on teacher's performance and student's achievement in Al-Ain Schools. The study addressed the two research questions (a). To what extent classroom density impact teacher's performance in Al-Ain Cycle Three Schools? (b) To what extent classroom density impact students' achievement in Al-Ain Cycle Three Schools? To have an in-depth understanding of whether class density impacted teaching and learning students, a quantitative method and a causal comparative design were conducted to collect data via two questionnaires; one for teachers, and another one for grade 12students. The findings revealed that classroom density impacted both the teacher's performance and students' achievement inappropriately. The study recommended reducing classroom students to foster the effectiveness of teachers and increase the achievement of students.

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Educating the individual is this country's most valuable investment. It represents the foundation for progress and development. -H.H. Sheikh Khalifa Bin Zayed Al Nahyan
Education is a top national priority, and that investment in human is the real investment to which we aspire. -H.H. Sheikh Mohammed Bin Zayed Al Nahyan

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