Market power appearance through game theoretic maintenance scheduling of distributed generations

The oligopoly structure of the market and the network constraints may produce results far from the perfect competition. Maintenance decisions in an oligopolistic electricity market have a strategic function, because GENCOs usually have impacts on market prices through capacity outages. This paper describes generation maintenance planning in an oligopolistic environment as a strategic decision. In this paper a game theoretic framework is modeled to analyze strategic behaviors of GENCOs. Each GENCO tries to maximize its payoff by strategically making decisions, taking into account its rival GENCOs' decisions. Some GENCOs own DG units, such as wind, diesel, biomass and fuel cell plants. If different GENCOs find out they have the conditions of exerting market power exact in maintenance periods; they will share their data and they will cause some area monopolies. Cournot-Nash equilibrium is used for decision making on maintenance problem in Oligopolistic electricity market. The Cournot-Nash problem is modeled as a mixed integer nonlinear programming optimization problem. The analytic framework presented in this paper enables joint assessment of maintenance and generation strategies. © 2011 Praise Worthy Prize S.r.l. -All rights reserved

Compliance of Healthcare Workers with Hand Hygiene Practices in the Northeast of Iran: an Overt Observation

Hand hygiene (HH) is one of the most effective methods to prevent transmission and spread of microorganisms from one patient to another, also, it used to reduce the spread of pathogens in clinical settings and to help control outbreaks but compliance is usually poor. The purpose of this study was to analyze the compliance of hand hygiene and affecting factors among healthcare workers (HCWs) of northeast hospitals in Iran. This study was conducted based on observation method for the compliance of hand hygiene according to the World Health Organization (WHO) guidelines. HCWs were observed during routine patient care in different shifts, also the technique of hand hygiene was assessed through hand washing with alcohol-based disinfectant. Data were collected during 1 year, from June 2014 to July 2015 by the infection control teams in the northeast hospital of Iran. By direct observation, we evaluated a total of 92518 hand hygiene opportunities from 29 hospitals in the northeast of Iran during 1 year, with overall compliance rates in these hospitals were 43.42%. Compliance rates differed by role: nurses43%, doctors 19 % and other health workers 29%. In this observational study, we identified that adherence to hand hygiene practice and use of alcohol-based disinfectant was very low in this hospitals, so effective intervention programs to promote adherence to hand hygiene and use of disinfectants could be effective to increase compliance

Investigating New Guaiazulenes and Diketopyrropyrroles for Photonic Applications

?-Conjugated systems have been the focus of study in recent years in order to understand their charge transport and optical properties for use in organic electronic devices, fluorescence bioimaging, sensors, and 3D optical data storage (ODS), among others. As a result, several molecular building blocks have been designed, allowing new frontiers to be realized. While various successful building blocks have been fine-tuned at both the electronic and molecular structure level to provide advanced photophysical and optoelectronic characteristics, the azulene framework has been under-appreciated despite its unique electronic and optical properties. Among several attributes, azulenes are vibrant blue naturally occurring hydrocarbons that exhibit large dipolar character, coupled with stimuli-responsive behavior in acidic environments. Additionally, the non-toxic nature and the accompanying eco-friendly feature of some azulenes, namely guaiazulene, may set the stage to further explore a more green route towards photonic and conductive materials. The first part of this dissertation focuses on exploiting guaiazulene as a natural building block for the synthesis of chromophores with varying stimuli-responsiveness. Results described in Chapter 1 show that extending the conjugation of guaiazulene through its seven-membered ring methyl group with aromatic substituents dramatically impacts the optical properties of the guaiazulenium carbocation. Study of these ?–stabilized tropilium ions enabled establishing photophysical structure-property trends for guaiazulene-terminated ?-conjugated analogs under acidic conditions, including absorption, emission, quantum yield, and optical band gap patterns. These results were exploited in the design of a photosensitive polymeric system with potential application in the field of three dimensional (3D) optical data storage (ODS). Chapter 2 describes the use of guaiazulene reactive sites (C-3 and C-4 methyl group) to generate a series of cyclopenta[ef]heptalenes that exhibit strong stimuli-responsive behavior. The approach presents a versatile route that allows for various substrates to be incorporated into the resulting cyclopenta[ef]heptalenes, especially after optimization that led to devising a one-pot reaction toward such tricyclic systems. Examining the UV-vis absorption profiles in neutral and acidic media showed that the extension of conjugation at C(4) of the cyclopenta[ef]heptalene skeleton results in longer absorption maxima and smaller optical energy gaps. Additionally, it was concluded that these systems act as sensitizers of a UV-activated (\u3c 300 nm) photoacid generator (PAG), via intermolecular photoinduced electron transfer (PeT), upon which the PAG undergoes photodecomposition resulting in the generation of acid. In a related study, the guaiazulene methyl group at C-4 was employed to study the linear and nonlinear optical properties of 4-styrylguaiazulenes, having the same ?–donor with varying ?-spacer. It was realized that the conjugation length correlates with the extent of bathochromic shift of the protonated species. On the other hand, a trend of decreasing quantum yield was established for this set of 4-styrylguaiazulenes, which can be explained by the increasingly higher degree of flexibility. The second part of this dissertation presents a comprehensive investigation of the linear photophysical, photochemical, and nonlinear optical properties of diketopyrrolopyrrole (DPP)-based derivatives, including two-photon absorption (2PA), femtosecond transient absorption, stimulated emission spectroscopy, and superfluorescence phenomena. The synthetic feasibility, ease of modification, outstanding robustness, and attractive spectroscopic properties of DPPs have motivated their study for fluorescence microscopy applications, concluding that the prepared DPP\u27s are potentially suitable chromophores for high resolution stimulated emission depletion (STED) microscopy

An Energy Efficient Mac Layer Design for Wireless Sensor Network

Recent technological advances in sensors, low power integrated circuits, and wireless communications have enabled the design of low-cost, lightweight, and intelligent wireless sensor nodes. The IEEE 802.15.4 standard is a specific Wireless Personal Area Network (WPAN) standard designed for various wireless sensor applications. Idle listening, packet collision, control packet overhead and overhearing are considered as energy consuming resources in WSNs. As the idle listening and packet collision are two major power consuming parts, we considered two solutions for reducing both of them to achieve an energy efficient protocol. We concentrate on the MAC layer design to overcome the energy consumption by radio management procedure and the backoff exponent mechanism. In the radio management, we analyze the contention part of the active duration of the MAC IEEE 802.15.4 standard superframe and allow nodes to enter the sleep state regarding to their available data for transmission instead of staying awake for the entire active period. This method will be useful especially when sensors do not have any data to send. The proposed non-persistent Carrier Sense Multiple Access (np-CSMA) protocol employs backoff exponent management mechanism. This algorithm helps the network to be reliable under traffic changes and saves more energy by avoiding collision. It assigns different range of BE (backoff exponent) to each node with respect to node’s contribution in network traffic. In our scheme a coordinator can observe the network traffic due to the data information associated with devices. It can manage the Personal Area Networks (PANs) devices by the beacon packet to go to sleep mode when they do not have any packet to send. In this thesis, by using the sleep period together with backoff exponent management in our protocol design, the amount of energy consumption will be reduced. The proposed model has been compared to original 802.15.4 standard and the existing Adaptive Backoff Exponent (ABE) MAC protocol to illustrate the improvement. Moreover, the BE management algorithm derives better system performance such as end-to-end delay, throughput, packet delivery ratio and Link Quality Indicator (LQI). The proposed model has been designed in such a way that the introduction of extra sleep period inserted in superframe improves the energy efficiency while maintaining other system performance parameters. The proposed MAC protocol has improved the energy consumption around 60% as compared to ABE-MAC. The proposed MAC protocol with an extra radio management technique together with backoff management procedure can achieve 70% more energy saving than MAC IEEE 802.15.4 standard

An analytical approximation to the solution of a wave equation by a variational iteration method

AbstractIn this work, a variational iteration method, which is a well-known method for solving functional equations, has been employed to solve the general form of a wave equation which governs numerous scientific and engineering experimentations. Some special cases of wave equations are solved as examples to illustrate the capability and reliability of the method. The results reveal that the method is very effective. The restrictions of the method are mentioned

Evaluation of exploiting coffee wastes in production of PLA green composites

Nowadays, lot of attention is devoted both to the application of bio-based polymers as promising alternative to the currently used petro-based polymers, and to the recycling of waste materials coming from agriculture industry. However, a series of economic barriers hinder the application of bio-based polymers in large scale. The aim of this study was to evaluate the application of PLA composites containing up to a 30 %wt of wastes deriving from coffee production. The waste was coffee silverskin which is the main byproduct of coffee roasting process. The composites were formulated in three different proportions of waste including 10 %wt, 20 %wt, and 30 %wt of the composites. The mechanical properties, microstructure, and crystallinity of the composites, as well as thermal stability, water uptake, and contact angle have been evaluated. The results show that coffee silverskin did not compromise the thermal stability and degree of crystallinity of the composites, while it changed the mechanical properties. Specifically, tensile strength gradually decreased on addition of coffee silverskin, while the Young’s modulus slightly increased. The distribution of filler throughout the matrix was almost homogeneous without porosities in the composites. An increase in the value of water uptake was obtained, but the water absorption behavior was not modified. Furthermore, the values of contact angle were constant for all the composites. Due to the production conditions of this study, in order to obtain acceptable properties for the composites, the amount of waste should be limited up to 20 %wt. The simple and low cost operations performed on the waste for obtaining the filler, lead to a decrease in material price on account of PLA reduction. Moreover, using coffee waste as filler in production of green composites, in addition to adding value to agricultural waste, would results in minimizing the dependency on petro-based polymers