Integrated plant monitoring to improve plant operation strategy and results

The more and more demanding conditions in the power generation sector requires to apply all the available technologies to optimize processes and reduce costs. An integrated asset management strategy, combining technical analysis and operation and maintenance management can help to improve plant performance, flexibility and reliability. In order to deploy such a model it is necessary to combine plant data and specific equipment condition information, with different systems devoted to analyze performance and equipment condition, and take advantage of the results to support operation and maintenance decisions. This model that has been dealt in certain detail for electricity transmission and distribution networks, is not yet broadly extended in the power generation sector, as proposed in this study for the case of a combined power plant. Its application would turn in direct benefit for the operation and maintenance and for the interaction to the energy market

Advanced Control Strategies for a 6 DoF Hydraulic Parallel Robot Based on the Dynamic Model

Nowadays robots have made their way into real applications that were prohibitive and unthinkable thirty years ago. This is mainly due to the increase in power computations and the evolution in the theoretical field of robotics and control. Even though there is plenty of information in the current literature on this topics, it is not easy to find clear concepts of how to proceed in order to design and implement a controller for a robot. In general, the design of a controller requires of a complete understanding and knowledge of the system to be controlled. Therefore, for advanced control techniques the systems must be first identified. Once again this particular objective is cumbersome and is never straight forward requiring of great expertise and some criteria must be adopted. On the other hand, the particular problem of designing a controller is even more complex when dealing with Parallel Manipulators (PM), since their closed-loop structures give rise to a highly nonlinear system. Under this basis the current work is developed, which intends to resume and gather all the concepts and experiences involve for the control of an Hydraulic Parallel Manipulator. The main objective of this thesis is to provide a guide remarking all the steps involve in the designing of advanced control technique for PMs. The analysis of the PM under study is minced up to the core of the mechanism: the hydraulic actuators. The actuators are modeled and experimental identified. Additionally, some consideration regarding traditional PID controllers are presented and an adaptive controller is finally implemented. From a macro perspective the kinematic and dynamic model of the PM are presented. Based on the model of the system and extending the adaptive controller of the actuator, a control strategy for the PM is developed and its performance is analyzed with simulation.

Targeting Gβγ signaling in arterial vascular smooth muscle proliferation: A novel strategy to limit restenosis

Restenosis continues to be a major problem limiting the effectiveness of revascularization procedures. To date, the roles of heterotrimeric G proteins in the triggering of pathological vascular smooth muscle (VSM) cell proliferation have not been elucidated. βγ subunits of heterotrimeric G proteins (Gβγ) are known to activate mitogen-activated protein (MAP) kinases after stimulation of certain G protein-coupled receptors; however, their relevance in VSM mitogenesis in vitro or in vivo is not known. Using adenoviral-mediated transfer of a transgene encoding a peptide inhibitor of Gβγ signaling (βARKct), we evaluated the role of Gβγ in MAP kinase activation and proliferation in response to several mitogens, including serum, in cultured rat VSM cells. Our results include the striking finding that serum-induced proliferation of VSM cells in vitro is mediated largely via Gβγ. Furthermore, we studied the effects of in vivo adenoviral-mediated βARKct gene transfer on VSM intimal hyperplasia in a rat carotid artery restenosis model. Our in vivo results demonstrated that the presence of the βARKct in injured rat carotid arteries significantly reduced VSM intimal hyperplasia by 70%. Thus, Gβγ plays a critical role in physiological VSM proliferation, and targeted Gβγ inhibition represents a novel approach for the treatment of pathological conditions such as restenosis.

Chemical chaperones mediate increased secretion of mutant α1-antitrypsin (α1-AT) Z: A potential pharmacological strategy for prevention of liver injury and emphysema in α1-AT deficiency

In α1-AT deficiency, a misfolded but functionally active mutant α1-ATZ (α1-ATZ) molecule is retained in the endoplasmic reticulum of liver cells rather than secreted into the blood and body fluids. Emphysema is thought to be caused by the lack of circulating α1-AT to inhibit neutrophil elastase in the lung. Liver injury is thought to be caused by the hepatotoxic effects of the retained α1-ATZ. In this study, we show that several “chemical chaperones,” which have been shown to reverse the cellular mislocalization or misfolding of other mutant plasma membrane, nuclear, and cytoplasmic proteins, mediate increased secretion of α1-ATZ. In particular, 4-phenylbutyric acid (PBA) mediated a marked increase in secretion of functionally active α1-ATZ in a model cell culture system. Moreover, oral administration of PBA was well tolerated by PiZ mice (transgenic for the human α1-ATZ gene) and consistently mediated an increase in blood levels of human α1-AT reaching 20–50% of the levels present in PiM mice and normal humans. Because clinical studies have suggested that only partial correction is needed for prevention of both liver and lung injury in α1-AT deficiency and PBA has been used safely in humans, it constitutes an excellent candidate for chemoprophylaxis of target organ injury in α1-AT deficiency.

A numerical strategy for efficient modeling of the equatorial wave guide

Convection in the tropics is observed to involve a wide-ranging hierarchy of scales from a few kilometers to the planetary scales and also has a profound impact on short-term climate. The mechanisms responsible for this behavior present a major unsolved problem. A promising emerging approach to address these issues is cloud-resolving modeling. Here a family of numerical models is introduced specifically to model the feedback of small-scale deep convection on tropical planetary waves and tropical circulation in a highly efficient manner compatible with the approach through cloud-resolving modeling. Such a procedure is also useful for theoretical purposes. The basic idea in the approach is to use low-order truncation in the meriodonal direction through Gauss–Hermite quadrature projected onto a simple discrete radiation condition. In this fashion, the cloud-resolving modeling of equatorially trapped planetary waves reduces to the solution of a small number of purely zonal two-dimensional wave systems along a few judiciously chosen meriodonal layers that are coupled only by some additional source terms. The approach is analyzed in detail with full mathematical rigor for linearized equatorial primitive equations with source terms.

Cardiac βARK1 inhibition prolongs survival and augments β blocker therapy in a mouse model of severe heart failure

Chronic human heart failure is characterized by abnormalities in β-adrenergic receptor (βAR) signaling, including increased levels of βAR kinase 1 (βARK1), which seems critical to the pathogenesis of the disease. To determine whether inhibition of βARK1 is sufficient to rescue a model of severe heart failure, we mated transgenic mice overexpressing a peptide inhibitor of βARK1 (βARKct) with transgenic mice overexpressing the sarcoplasmic reticulum Ca2+-binding protein, calsequestrin (CSQ). CSQ mice have a severe cardiomyopathy and markedly shortened survival (9 ± 1 weeks). In contrast, CSQ/βARKct mice exhibited a significant increase in mean survival age (15 ± 1 weeks; P < 0.0001) and showed less cardiac dilation, and cardiac function was significantly improved (CSQ vs. CSQ/βARKct, left ventricular end diastolic dimension 5.60 ± 0.17 mm vs. 4.19 ± 0.09 mm, P < 0.005; % fractional shortening, 15 ± 2 vs. 36 ± 2, P < 0.005). The enhancement of the survival rate in CSQ/βARKct mice was substantially potentiated by chronic treatment with the βAR antagonist metoprolol (CSQ/βARKct nontreated vs. CSQ/βARKct metoprolol treated, 15 ± 1 weeks vs. 25 ± 2 weeks, P < 0.0001). Thus, overexpression of the βARKct resulted in a marked prolongation in survival and improved cardiac function in a mouse model of severe cardiomyopathy that can be potentiated with β-blocker therapy. These data demonstrate a significant synergy between an established heart-failure treatment and the strategy of βARK1 inhibition.

Neuroprotective strategy for Alzheimer disease: intranasal administration of a fatty neuropeptide.

Neurodegenerative diseases, in which neuronal cell disintegrate, bring about deteriorations in cognitive functions as is evidenced in millions of Alzheimer patients. A major neuropeptide, vasoactive intestinal peptide (VIP), has been shown to be neuroprotective and to play an important role in the acquisition of learning and memory. A potent lipophilic analogue to VIP now has been synthesized, [stearyl-norleucine17]VIP ([St-Nle17]VIP), that exhibited neuroprotection in model systems related to Alzheimer disease. The beta-amyloid peptide is a major component of the cerebral amyloid plaque in Alzheimer disease and has been shown to be neurotoxic. We have found a 70% loss in the number of neurons in rat cerebral cortical cultures treated with the beta-amyloid peptide (amino acids 25-35) in comparison to controls. This cell death was completely prevented by cotreatment with 0.1 pM [St-Nle17]VIP. Furthermore, characteristic deficiencies in Alzheimer disease result from death of cholinergic neurons. Rats treated with a cholinergic blocker (ethylcholine aziridium) have been used as a model for cholinergic deficits. St-Nle-VIP injected intracerebroventricularly or delivered intranasally prevented impairments in spatial learning and memory associated with cholinergic blockade. These studies suggest both an unusual therapeutic strategy for treatment of Alzheimer deficiencies and a means for noninvasive peptide administration to the brain.

Genetic footprinting: a genomic strategy for determining a gene's function given its sequence.

This report describes an efficient strategy for determining the functions of sequenced genes in microorganisms. A large population of cells is subjected to insertional mutagenesis. The mutagenized population is then divided into representative samples, each of which is subjected to a different selection. DNA is prepared from each sample population after the selection. The polymerase chain reaction is then used to determine retrospectively whether insertions into a particular sequence affected the outcome of any selection. The method is efficient because the insertional mutagenesis and each selection need only to be performed once to enable the functions of thousands of genes to be investigated, rather than once for each gene. We tested this "genetic footprinting" strategy using the model organism Saccharomyces cerevisiae.

A gene therapy strategy using a transcription factor decoy of the E2F binding site inhibits smooth muscle proliferation in vivo.

The application of DNA technology to regulate the transcription of disease-related genes in vivo has important therapeutic potentials. The transcription factor E2F plays a pivotal role in the coordinated transactivation of cell cycle-regulatory genes such as c-myc, cdc2, and the gene encoding proliferating-cell nuclear antigen (PCNA) that are involved in lesion formation after vascular injury. We hypothesized that double-stranded DNA with high affinity for E2F may be introduced in vivo as a decoy to bind E2F and block the activation of genes mediating cell cycle progression and intimal hyperplasia after vascular injury. Gel mobility-shift assays showed complete competition for E2F binding protein by the E2F decoy. Transfection with E2F decoy inhibited expression of c-myc, cdc2, and the PCNA gene as well as vascular smooth muscle cell proliferation both in vitro and in the in vivo model of rat carotid injury. Furthermore, 2 weeks after in vivo transfection, neointimal formation was significantly prevented by the E2F decoy, and this inhibition continued up to 8 weeks after a single transfection in a dose-dependent manner. Transfer of an E2F decoy can therefore modulate gene expression and inhibit smooth muscle proliferation and vascular lesion formation in vivo.

Outsourcing and strategy in Spanish town halls: a field study

Purpose – This study seeks to analyse the links between strategies, structures and processes in the case of the largest Spanish town halls, using the Miles and Snow's models about organisational strategies, and asking the following questions: “What is the situation of municipal services' outsourcing in the largest Spanish town halls?”; “Do Spanish town halls follow the strategies suggested in Miles and Snow's model?”; and “Is there a relationship between the strategic position adopted by town halls and their stance on outsourcing?”. Design/methodology/approach – In order to achieve these aims a questionnaire was administered to the human resource managers in the town halls of the largest Spanish cities. Findings – The paper finds that outsourcing is a complement, which seeks to improve the services delivered, and local institutions do not resort to it due to a lack of internal resources but as a way to complement their own capabilities. Originality/value – The paper has identified three distinct strategic profiles in the town halls interviewed which coincide with the profiles that Miles and Snow call prospective, defensive and reactive strategies. It reveals that town halls which outsource to a greater extent are the ones which identify more with the prospective or reactive strategy, whereas those which outsource less are closer to the defensive strategy.

Strategy-proof choice of acts : a preliminary study

We model social choices as acts mapping states of the world to (social) outcomes. A (social choice) rule assigns an act to every profile of subjective expected utility preferences over acts. A rule is strategy-proof if no agent ever has an incentive to misrepresent her beliefs about the world or her valuation of the outcomes; it is ex-post efficient if the act selected at any given preference profile picks a Pareto-efficient outcome in every state of the world. We show that every two-agent ex-post efficient and strategy-proof rule is a top selection: the chosen act picks the most preferred outcome of some (possibly different) agent in every state of the world. The states in which an agent’s top outcome is selected cannot vary with the reported valuations of the outcomes but may change with the reported beliefs. We give a complete characterization of the ex-post efficient and strategy-proof rules in the two-agent, two-state case, and we identify a rich class of such rules in the two-agent case.

The gas target model for the Visegard 4 Region: conceptual analysis. OSW Report, May 2013

The similarity of issues and geographical proximity have led the Visegrad 4 countries (V4) to undertake closer collaboration in natural gas policy, notably by agreeing on a common security of supply strategy, including regional emergency planning, and a common implementation of the Gas Target Model (GTM) that European regulators have proposed for the medium-long term design of the EU gas market, and which has been endorsed by the Madrid Regulatory Forum. As a contribution to this collaboration, the present paper will analyse how the GTM may be implemented in the V4 region, with a view to maximize the benefits that arise from joint implementation. A most relevant conclusion of the GTM is that markets should be large enough to attract market players and investments, so that sufficient diversity of sources may be reached and market power indicators are kept below dangerous levels. In most cases, this requires physical and/or virtual interconnection of present markets, which is also useful to achieve the required security of supply standards, as envisaged in the Regulation 994/2010/EC.

Technology diffusion, services, and endogenous growth in Europe. Is the Lisbon Strategy still alive? Bruges European Economic Research (BEER) Papers 2/May 2005

We explore the role of business services in knowledge accumulation and growth and the determinants of knowledge diffusion including the role of distance. A continuous time model is estimated on several European countries, Japan, and the US. Policy simulations illustrate the benefits for EU growth of the deepening of the single market, the reduction of regulatory barriers, and the accumulation of technology and human capital. Our results support the basic insights of the Lisbon Agenda. Economic growth in Europe is enhanced to the extent that: trade in services increases, technology accumulation and diffusion increase, regulation becomes both less intensive and more uniform across countries, and human capital accumulation increases in all countries.

The Reallocation of Agricultural Labour across Sectors: An Empirical Strategy for Micro Data. Factor Markets Working Document No. 45, May 2013

This paper presents an empirical methodology for studying the reallocation of agricultural labour across sectors from micro data. Whereas different approaches have been employed in the literature to better understand the mobility of labour, looking at the determinants to exit farm employment and enter off-farm activities, the initial decision of individuals to work in agriculture, as opposed to other sectors, has often been neglected. The proposed methodology controls for the selectivity bias, which may arise in the presence of a non-random sample of the population, in this context those in agricultural employment, which would lead to biased and inconsistent estimates. A 3-step multivariate probit with two selection and one outcome equations constitutes the selected empirical approach to explore the determinants of farm labour to exit agriculture and switch occupational sector. The model can be used to take into account the different market and production structures across European member states on the allocation of agricultural labour and its adjustments.

The Danish Flexicurity Model - a Lesson for the US? ACES Working Paper No. 2, May 2007

Within recent years, increasing international competition has caused an increase in job transitions worldwide. Many countries find it difficult to manage these transitions in a way that ensures a match between labour and demand. One of the countries that seem to manage the transitions in a successful way is Denmark, where unemployment has been dropping dramatically over the last decade without a drop in job quality. This success is ascribed the so-called Danish flexicurity model, where an easy access to hiring and firing employees (flexibility) is combined with extensive active and passive labour market policies (security). The Danish results have gained interest not only among other European countries, where unemployment rates remain high, but also in the US, where job loss is often related to lower job quality. It has, however, been subject to much debate both in Europe and in the US, whether or not countries with distinctively different political-economic settings can learn from one another. Some have argued that cultural differences impose barriers to successful policy transfer, whereas others see it as a perfectly rational calculus to introduce 'best practices' from elsewhere. This paper presents a third strategy. Recent literature on policy transfer suggests that successful cross national policy transfer is possible, even across the Atlantic, but that one must be cautious in choosing the form, content and level of the learning process. By analysing and comparing the labour market policies and their settings in Denmark and the US in detail, this paper addresses the question, what and how the US can learn from the Danish model. Where the US and Denmark share a high degree of flexibility, they differ significantly on the level of security. This also means that the Danish budget for active and passive labour market policies is significantly higher than the American, and it seems unlikely that political support for the introduction of Danish levels of security in the US can be established. However, the paper concludes that there is a learning potential between the US and Demnark in the different local level efficiency of the money already spent. A major reason for the Danish success has been the introduction of tailor made initiatives to the single displaced worker and a stronger coordination between local level actors. Both of which are issues, where a lack of efficiency in the implementation of American active labour market policies has been reported.