Optimal Water Allocation Planning Using a Water-Energy-Food Nexus Approach: The Case of Matagorda County, TX

Conventional methods for analyzing the influences of water planning decisions frequently miss the dynamic interconnections between water, energy, and food (WEF) resources. This study presents a platform to analyze the feasibility of possible interventions and recommend scenarios to enhance WEF resource sustainability. A water-centric framework includes a unique analytic tool for quantification of the tradeoffs for future scenarios consisting of interventions, and a sustainability analysis for drawing recommendations for future water allocation in light of WEF inter-linkages. The applied case is Matagorda County, which, despite ample water resources, is considered one of the most water stressed area of Texas due to high demands on water resources from agriculture and energy sectors. The possible interventions mostly include water-related infrastructure such as building desalination plant, treatment facility, improving existing canal system, applying high-tech on-farm irrigation, changing cooling system of the nuclear plant, and building their conveyance systems. A great number of scenarios consisting of combinations of possible interventions are developed. The analytic tool produces quantitative parameters for each scenario. A sustainability analysis using the parameters produced by the tool enables presentations of advisable water, energy, food, environment, or cost -centric and optimal scenarios. The findings of the study present most sustainable combinations of water-related infrastructure that can protect primary resources as well as contribute economic well-being of Matagorda County

Frequency and phase locking of a CW magnetron:with a digital phase locked loop using pushing characteristics

The main body of work presented in this thesis is precise frequency and phase control of a 1.2 kW CW cooker magnetron (National 2M137) locked to a 10 MHz reference injected with a very small RF signal (of the order of -40 dBc) creating a suitable RF source for particle accelerators and other sophisticated applications. We will go on to discuss the characterization of the magnetron with differing heater powers and load conditions when operated with a low cost switched mode power supply. We similarly identify three different regimes of the magnetron operation with respect to the heater power: firstly low noise operation for small heater powers (up to 15W), secondly unstable operation for mid-range heater powers (15W to 30W) and thirdly high noise operation at high heater powers (30W to 54W). We then introduce a novel method to lock the magnetron output frequency to the 10 MHz reference using a digital frequency synthesizer IC (Analog Devices ADF4113) in a negative feedback loop, with this method we exploit the use of the pushing mechanism where the ADF41113 controls the power supply output to vary the magnetron’s anode current, keeping its natural frequency locked to the reference. We next investigate the injection locking of the frequency locked magnetron with small injection levels (-29 dBc to -43 dBc) under differing operating conditions and observe a phase jitter performance of the order of+/-13 o for very small heater power and -29 dBc injection level. We then fast switch/ramp the injection phase and establish the maximum rate of change of the magnetron output phase. This rate was found to be 4p/us for -29 dBc injection level and 44W heater power. We finally discuss the implementation of a fast DSP based feedback control on the injection phase to improve the magnetron phase jitter performance to below 1o r.m.s

Use of self-calibration data for multifunctional MEMS sensor prognostics

This paper proposes a solution to monitor the degradation of a multifunctional microelectromechanical systems (MEMS) sensor (MFS) and to recalibrate the sensor output accordingly. The solution is able to predict the remaining useful life based on the recalibration history. The MFS used is a dual pressure-humidity hybrid sensor where model data have been used to demonstrate the applicability and performance of the proposed method for diagnosis, self-correction, and prognosis

Predicting the Impact of Batch Refactoring Code Smells on Application Resource Consumption

Automated batch refactoring has become a de-facto mechanism to restructure software that may have significant design flaws negatively impacting the code quality and maintainability. Although automated batch refactoring techniques are known to significantly improve overall software quality and maintainability, their impact on resource utilization is not well studied. This paper aims to bridge the gap between batch refactoring code smells and consumption of resources. It determines the relationship between software code smell batch refactoring, and resource consumption. Next, it aims to design algorithms to predict the impact of code smell refactoring on resource consumption. This paper investigates 16 code smell types and their joint effect on resource utilization for 31 open source applications. It provides a detailed empirical analysis of the change in application CPU and memory utilization after refactoring specific code smells in isolation and in batches. This analysis is then used to train regression algorithms to predict the impact of batch refactoring on CPU and memory utilization before making any refactoring decisions. Experimental results also show that our ANN-based regression model provides highly accurate predictions for the impact of batch refactoring on resource consumption. It allows the software developers to intelligently decide which code smells they should refactor jointly to achieve high code quality and maintainability without increasing the application resource utilization. This paper responds to the important and urgent need of software engineers across a broad range of software applications, who are looking to refactor code smells and at the same time improve resource consumption. Finally, it brings forward the concept of resource aware code smell refactoring to the most crucial software applications

Parameterized Disturbance Observer Based Controller to Reduce Cyclic Loads of Wind Turbine

This paper is concerned with bump-less transfer of parameterized disturbance observer based controller with individual pitch control strategy to reduce cyclic loads of wind turbine in full load operation. Cyclic loads are generated due to wind shear and tower shadow effects. Multivariable disturbance observer based linear controllers are designed with objective to reduce output power fluctuation, tower oscillation and drive-train torsion using optimal control theory. Linear parameterized controllers are designed by using a smooth scheduling mechanism between the controllers. The proposed parameterized controller with individual pitch was tested on nonlinear Fatigue, Aerodynamics, Structures, and Turbulence (FAST) code model of National Renewable Energy Laboratory (NREL)’s 5 MW wind turbine. The closed-loop system performance was assessed by comparing the simulation results of proposed controller with a fixed gain and parameterized controller with collective pitch for full load operation of wind turbine. Simulations are performed with step wind to see the behavior of the system with wind shear and tower shadow effects. Then, turbulent wind is applied to see the smooth transition of the controllers. It can be concluded from the results that the proposed parameterized control shows smooth transition from one controller to another controller. Moreover, 3p and 6p harmonics are well mitigated as compared to fixed gain DOBC and parameterized DOBC with collective pitch

Influence of Cracks on the Carbonation Resistance of Concrete Structures

Carbonation-induced corrosion of steel rebar embedded in concrete is one of the major issues influencing durability of reinforced concrete structures. It has been acknowledged that structural cracks in concrete influences the carbon dioxide (CO2) diffusivity and accelerates the carbonation-induced reinforcement corrosion, however most of the previous studies on the carbonation induced corrosion have concentrated on the un-cracked / unloaded concrete. This study investigates the impact of cracks caused by loading on the depth of carbonation into concrete. Concrete prisms (100x100x500 mm) were subjected to four different crack widths (0, 0.05-0.15 mm, 0.15-0.25 mm and 0.25-0.35 mm) and the carbonation depth was determined using an accelerated environment test programme based on the CEN/TS 12390-10:2007 and XRD analysis. The impact of replacing OPC cement by pulverized fuel ash (PFA) and ground granulated blast furnace slag (GGBS) on the carbonation depth in cracked concrete was also investigated. The results show a considerable influence of crack width on the depth of carbonation and the X-ray powder diffraction analysis (XRD) confirms these results. The penetration of carbon dioxide and accumulation of carbonation compound (CaCO3) were found to be concentrated at crack locations, whereas the carbonation depths at other locations were found to be less than the carbonation depth in un-cracked concrete. The results also demonstrate a significant increase in the penetration of carbonation due to the addition of supplementary materials in the samples when compared to the reference mixes