Assessment of oxyfuel power generation technologies

In this work, a cost–benefit analysis concerning the use of oxyfuel combustion technology is carried out. For the analysis, the IPP optimization software is used in which a decouple optimization method for power technology selection in competitive markets is employed and the electricity unit cost and the CO₂ avoidance cost are calculated. The results indicate that oxyfuel technology is a competitive CO₂ capture and storage (CCS) technology. In addition, the effect of varying loan interest rates was investigated in the economic performance of an oxyfuel combustion plant. This analysis, revealed that up to a value of loan interest of approximately 5.3% the oxyfuel plant retains the competitive electricity unit costs (compared to other CCS technologies). For higher interest rate levels, other CCS technologies become more economically attractive.     

Bond strengths of resin-to-metal bonding systems

STATEMENT OF PROBLEM: Resinous materials for the veneers of fixed prostheses commonly require mechanical retention on metal substructures because there is no chemical adhesion. However, mechanical retention does not restrict creation of a marginal gap at the resin-metal interface, which can cause discoloration or detachment of resinous material. The development of a chemical resin-to-metal bonding could resolve this problem and also reduce the need for mechanical retention (pearls, wires) on metal frameworks. PURPOSE: This study evaluated six current methods with the use of various storage conditions to predict clinical efficacy. MATERIAL AND METHODS: Six resin-to-metal bonding systems were tested: Silicoater, Silicoater MD, Rocatec, OVS, Sebond, and Spectra-Link. All specimens were examined in bending tests after 24 hours of dry storage (category A), after 24 hours of water storage and thermocycling (category B), and after 2 months of water storage and thermocycling (category C). Tensional tests were completed for all bonding systems after dry storage, and microscopic examination (optical and SEM) was performed for all specimens. RESULTS AND CONCLUSIONS: This study indicated that certain systems can provide stable bonding of resin to metal substructures despite prolonged wet storage and intensive thermocycling. These systems can also be used clinically without retentive configurations on metal frameworks, resulting in better esthetics. Some bonding systems revealed progressive weakening of bond strengths, so research is needed to verify their clinical efficacy.     

Dynamic bandwidth allocation in DVB-T networks providing IP services

The combination of high capacity, signal robustness, and worldwide acceptance have made digital terrestrial broadcasting (DVB-T) one of today's more promising technologies, while newly adopted standards support the integration of digital television programs and data services within a single multiplex, offered to both stationary and mobile end users. The paper addresses the issue of optimal bit rate allocation among DTV and IP services within the DVB-T multiplex, and demonstrates a novel configuration providing real-time sharing of the available bandwidth via an algorithm based on service hierarchy and perceptual quality assessment. The architecture and performance of a fully functional DVB-T testbed developed on this concept is also presented.     

IMPLEMENTATION OF HAZARD ANALYSIS CRITICAL CONTROL POINT (HACCP) SYSTEM TO THE ALCOHOLIC BEVERAGES INDUSTRY

Alcoholic beverages (fermented or not) have been consumed for more than three thousand years and, generally, they have been considered safe because of their alcohol content. However, in recent years adulteration (i.e., use of low-cost, inappropriate alcohol) has made rapid progress in this field. Food and drink control and safety can be assured within the frame of strict adherence to quality and safety systems (ISO 9000 series, HACCP and TQM). The flow diagrams for the production of several alcohol drinks were shown, and an extensive hazard analysis critical control point (HACCP) analysis was carried out in order to reveal the weaknesses of the production line and to suggest the critical limits in compliance with legislation and the corresponding preventive and corrective measures.     

Broadband multimedia on the move with DVB-H

DVB-H is the newly standardized extension to DVB-T, aiming at the provision of IP datacasting (IPDC) services to mobile terminals. This tutorial paper outlines the structure of an interactive DVB-H platform and presents in brief the technical advances of the new specification. It also discusses some interesting scenarios of interactive and non-interactive services which can be directly deployed with the use of the DVB-H technology either as a stand-alone broadcast network or as a complement to existing cellular (2G/3G/WLAN) infrastructures.     

Analysis of enterovirus and adenovirus presence in swimming pools in Cyprus from 2007-2008

An analysis was carried out to determine the presence of enteroviruses and adenoviruses in public swimming pools in Cyprus. The effectiveness of the commonly implemented disinfection procedure of chlorination was confirmed by determination of bacteriological markers. Analysis of viral presence was carried out by sampling random swimming pools from the five major cities in Cyprus during a period of 21 months spanning from April 2007 to December 2008. A 10 I sample was taken from each swimming pool to be tested and was subsequently concentrated via membrane filtration using a new methodological approach for virus elution. Concentrated samples were analysed using of a Real Time Polymerase Chain Reaction (PCR) TaqMan probe based approach to detect the presence of enteroviruses and adenoviruses. Over the period of 21 months a total of 126 swimming pools were sampled and analysed. In four swimming pools enteroviruses were detected, in one pool echovirus 18 was identified, in two pools echovirus 30 was identified and in one other pool poliovirus Sabin 1 was identified. Similarly, in four swimming pools adenoviruses were detected, in all four adenovirus 41 was identified. Bacteriological marker analysis showed that 98% of pools complied with Cyprus regulations.     

IMPLEMENTATION OF HAZARD ANALYSIS CRITICAL CONTROL POINT (HACCP) SYSTEM TO THE NON-ALCOHOLIC BEVERAGE INDUSTRY

Non-alcoholic beverages, particularly, bottled water and fruit juices (carbonated and non-carbonated) are the most widespread food industries worldwide. The industry objective is to process at the lowest possible cost while maintaining the organoleptic stability and quality of the final product. The latter can be achieved through strict adherence to quality (ISO 9001/2) and safety (HACCP) management systems. The flow diagrams for the production of bottled water, several juices (orange, lemon, apple), carbonated drinks, coffee and tea are shown accompanied with a synoptical implementation of the HACCP system (critical control points, critical limits, preventive and corrective actions).     

Unidirectional lightweight encapsulation: performance evaluation and application perspectives

Multi Protocol Encapsulation (MPE) is today the dominant method for encapsulating IP data into the MPEG-2 Transport Stream so they can be conveyed over digital television platforms (DVB or ATSC). Unidirectional Lightweight Encapsulation (ULE) is a new alternative to MPE, providing simplicity, efficiency and configurability. This paper presents the principle and benefits of ULE, approaches the issues associated with its adoption and compares it against MPE through extensive performance measurements in a fully functional testbed under IPv4 and IPv6 load. It also proposes, implements and demonstrates the combination of MPEG-4/H.264, IPv6 and ULE as the most efficient and flexible protocol stack for next-generation transmission of digital video over Digital Television networks.     

A framework for end-to-end video quality prediction of MPEG video

This paper proposes, describes and evaluates a novel framework for video quality prediction of MPEG-based video services, considering the perceptual degradation that is introduced by the encoding process and the provision of the encoded signal over an error-prone wireless or wire-line network. The concept of video quality prediction is considered in this work, according to which the encoding parameters of the video service and the network QoS conditions are used for performing an estimation/prediction of the video quality level at the user side, without further processing of the actual encoded and transmitted video content. The proposed prediction framework consists of two discrete models: (i) a model for predicting the video quality of an encoded signal at a pre-encoding stage by correlating the spatiotemporal content dynamics to the bit rate that satisfies a specific level of user satisfaction; and (ii) a model that predicts primarily the undecodable frames (and subsequently the perceived quality degradation caused by them) based on the monitored averaged packet loss ratio of the network. The proposed framework is experimentally tested and validated with video signals encoded according to MPEG-4 standard.     

Optimum bit allocation algorithm for DMT-based systems underminimum transmitted power constraint

An algorithm for allocating bits to several carriers of a discrete multitone (DMT) symbol is proposed. The target of the algorithm is to assign the required bits (supported service) among the carriers so that the transmitted power is kept to a minimum. Ultimately, this algorithm is a transmitted power back-off algorithm which enables the system to operate at the minimum required power, resulting in the minimisation of the crosstalk interference to other systems located in the same binder group. Even though this algorithm was originally designed according the very high speed digital subscriber line system specifications, it can equally be used in every DMT-based digital subscriber line system such as asymmetrical digital subscriber line systems