Coordinated Control of Energy Storage in Networked Microgrids under Unpredicted Load Demands

In this paper a nonlinear control design for power balancing in networked microgrids using energy storage devices is presented. Each microgrid is considered to be interfaced to the distribution feeder though a solid-state transformer (SST). The internal duty cycle based controllers of each SST ensures stable regulation of power commands during normal operation. But problem arises when a sudden change in load or generation occurs in any microgrid in a completely unpredicted way in between the time instants at which the SSTs receive their power setpoints. In such a case, the energy storage unit in that microgrid must produce or absorb the deficit power. The challenge lies in designing a suitable regulator for this purpose owing to the nonlinearity of the battery model and its coupling with the nonlinear SST dynamics. We design an input-output linearization based controller, and show that it guarantees closed-loop stability via a cascade connection with the SST model. The design is also extended to the case when multiple SSTs must coordinate their individual storage controllers to assist a given SST whose storage capacity is insufficient to serve the unpredicted load. The design is verified using the IEEE 34-bus distribution system with nine SST-driven microgrids.Comment: 8 pages, 10 figure

Viscous compressible aligned MFD flows.

Dept. of Mathematics and Statistics. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1987 .H873. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.Sc.)--University of Windsor (Canada), 1987

Exact solutions of steady plane potential compressible flows: A new approach.

The aim of this dissertation is the integration of the governing equations of motion for steady, two-dimensional potential gas flows. Although there has been an ongoing search for the solutions of these equations for over one hundred and fifty years, only a limited number of exact solutions in closed form exist prior to this thesis. The methods or processes that were employed in the past inevitably required dealing with a non-linear partial differential equation in the potential function with unmanageable boundary conditions or pre-deciding the type of gas that flows along a flow pattern. By adopting and pursuing a new approach, exact solutions in closed form are obtained in this thesis. This approach specifies a priori the form of the streamline pattern or a specific geometric pattern and determines the exact solution and the permissible gas for each chosen pattern. This approach also obtains exact solutions of the non-linear partial differential equation in the potential function even though it does not deal directly with this equation. This dissertation contains two parts. The first part treats and develops investigations when the forms for the flow patterns are considered. Following the classification of all permissible flows for the chosen forms, exact solutions for these permissible flows are determined. The second part of this thesis is concerned with specified streamline patterns defined by Re$\lbrack f(z)\rbrack$ = constant or a linear combination of Re$\lbrack f(z)\rbrack$ and Im$\lbrack f(z)\rbrack$ equal to any constant when f(z) is a known analytic function of z. This new approach involves transformations of independent variables only so that systems of ordinary differential equations and linear partial differential are dealt with. New and existing exact solutions in closed form of these equations are obtained. However, in some cases, the transformation employed yielded nonlinear ordinary differential equations for which only particular solutions were obtained. In addition, equations of state corresponding to these solutions are also determined and analyzed. The exact solutions for incompressible, inviscid and irrotational flows can also be easily obtained by this new approach.Dept. of Mathematics and Statistics. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1994 .H875. Source: Dissertation Abstracts International, Volume: 56-11, Section: B, page: 6154. Adviser: O. P. Chandna. Thesis (Ph.D.)--University of Windsor (Canada), 1994

Synthesis and antimicrobial evaluation of fatty chain substituted 2,5-dimethyl pyrrole and 1,3-benzoxazin-4-one derivatives

AbstractFatty acids themselves have a number of biological properties and its easy intake by the human body will focus to the synthesis of many heterocyclic moiety substituted with fatty acid residue, to make more gradual intake of heterocycles in the human body. 2,5-Dimethyl pyrrole 2(a–e) and 1,3-benzoxazin-4-one 4(b–e) derivatives were synthesized, from cyclization of fatty acid hydrazide 1(a–e) with acetonyl acetone and from the reaction of fatty esters 3(b–e) with anthranilic acid in the presence of POCl3, respectively. All these compounds were characterized with the help of IR, 1H NMR, 13C NMR and mass spectra. The synthesized compounds were screened for antimicrobial evaluation against gram-positive (Staphylococcus aureus SA 22, Bacillus subtilis MTCC 121), gram-negative (Escherichia coli K12, Klebsiella pneumoniae) and fungal strains (Candida albicans IOA-109) and were found to be good antimicrobial agents

Thermal Performance Evaluation of Seawater Cooling Towers

Seawater has been used for long time as a cooling fluid in heat exchangers to reduce fresh water usage in industry and power plants. The thermophysical properties of seawater are different from those of fresh water due to the salt content or salinity. This difference is sufficient to affect the heat and mass transfer processes which in turn change the thermal performance. Thermal design of fresh water cooling towers is described in detail in many textbooks and handbooks. However, only a rule of thumb is frequently used for designing of seawater cooling towers. This rule recommends degrading the tower performance by approximately 1% for every 10,000 ppm of salts in the feed water. In this paper, the thermal performance of seawater cooling towers is presented using a detailed model of counterflow wet cooling towers which takes into consideration the coupled simultaneous heat and mass transfer processes and uses state-of-the-art seawater properties from the literature. The model governing equations are solved numerically and the validity of this model is checked using new experimental data that has been measured using a bench top counterflow seawater cooling tower. The effect of the variation of seawater salinity as well as other operating conditions on the effectiveness and Merkel number is investigated.Center for Clean Water and Clean Energy at MIT and KFUP

Computationally efficient design procedure for single-layer IPM machines

Interior Permanent Magnet machines are widely used in several applications thanks to their optimal tradeoff between torque and flux weakening capability figures. Their design process massively relies on the use of optimization algorithms coupled with Finite Elements Analysis, as dictated by the high number of input parameters and the inadequateness of design equations. This paper proposes a faster design flowchart, based on analytical models for V-type IPM machines. The proposed design procedure is validated against FEA results, referring to the known benchmark of the Toyota Prius 2010 electric motor. Although the precision of the results is not comparable to that obtainable with FEA, the proposed closed-form model is useful and insightful during the preliminary stages of the design. The limits of accuracy of the proposed equations are commented critically. Guidelines are given on how to embed the presented approach into a comprehensive design procedure

Sustainable green nanoadsorbents for remediation of pharmaceuticals from water and wastewater: A critical review

In the last three decades, pharmaceutical research has increased tremendously to offer safe and healthy life. However, the high consumption of these harmful drugs has risen devastating impact on ecosystems. Therefore, it is worldwide paramount concern to effectively clean pharmaceuticals contaminated water streams to ensure safer environment and healthier life. Nanotechnology enables to produce new, high-technical material, such as membranes, adsorbent, nano-catalysts, functional surfaces, coverages and reagents for more effective water and wastewater cleanup processes. Nevertheless, nano-sorbent materials are regarded the most appropriate treatment technology for water and wastewater because of their facile application and a large number of adsorbents. Several conventional techniques have been operational for domestic wastewater treatment but are inefficient for pharmaceuticals removal. Alternatively, adsorption techniques have played a pivotal role in water and wastewater treatment for a long, but their rise in attraction is proportional with the continuous emergence of new micropollutants in the aquatic environment and new discoveries of sustainable and low-cost adsorbents. Recently, advancements in adsorption technique for wastewater treatment through nanoadsorbents has greatly increased due to its low production cost, sustainability, better physicochemical properties and high removal performance for pharmaceuticals. Herein, this review critically evaluates the performance of sustainable green nanoadsorbent for the remediation of pharmaceutical pollutants from water. The influential sorption parameters and interaction mechanism are also discussed. Moreover, the future prospects of nanoadsorbents for the remediation of pharmaceuticals are also presented

Seed Extract of Psoralea corylifolia and Its Constituent Bakuchiol Impairs AHL-Based Quorum Sensing and Biofilm Formation in Food- and Human-Related Pathogens

The emergence of multi-drug resistance in pathogenic bacteria in clinical settings as well as food-borne infections has become a serious health concern. The problem of drug resistance necessitates the need for alternative novel therapeutic strategies to combat this menace. One such approach is targeting the quorum-sensing (QS) controlled virulence and biofilm formation. In this study, we first screened different fractions of Psoralea corylifolia (seed) for their anti-QS property in the Chromobacterium violaceum 12472 strain. The methanol fraction was found to be the most active fraction and was selected for further bioassays. At sub-inhibitory concentrations, the P. corylifolia methanol fraction (PCMF) reduced QS-regulated virulence functions in C. violaceum CVO26 (violacein); Pseudomonas aeruginosa (elastase, protease, pyocyanin, chitinase, exopolysaccharides (EPS), and swarming motility), A. hydrophila (protease, EPS), and Serratia marcescens (prodigiosin). Biofilm formation in all the test pathogens was reduced significantly (p ≤ 0.005) in a concentration-dependent manner. The β-galactosidase assay showed that the PCMF at 1,000 μg/ml downregulated las-controlled transcription in PAO1. In vivo studies with C. elegans demonstrated increased survival of the nematodes after treatment with the PCMF. Bakuchiol, a phytoconstituent of the extract, demonstrated significant inhibition of QS-regulated violacein production in C. violaceum and impaired biofilm formation in the test pathogens. The molecular docking results suggested that bakuchiol efficiently binds to the active pockets of LasR and RhlR, and the complexes were stabilized by several hydrophobic interactions. Additionally, the molecular dynamics simulation of LasR, LasR–bakuchiol, RhlR, and RhlR–bakuchiol complexes for 50 ns revealed that the binding of bakuchiol to LasR and RhlR was fairly stable. The study highlights the anti-infective potential of the PCMF and bakuchiol instead of bactericidal or bacteriostatic action, as the extract targets QS-controlled virulence and the biofilm