Minimizing the Impact of SCR Catalyst on Total Generating Cost Through Effective Catalyst Management

2004 ◽  
Author(s):  
James E. Staudt
Keyword(s):  
System Performance ◽  
Catalytic Reduction ◽  
Management Strategies ◽  
Nox Reduction ◽  
Analysis Tool ◽  
Predictive Tools ◽  
Trade Offs ◽  
Wide Range ◽  
Parasitic Load ◽  
The Impact

For coal-fired boilers equipped with Selective Catalytic Reduction (SCR) NOx reduction technology, direct catalyst cost contributes to a major operating expense. Decisions regarding catalyst management have other significant impacts to generating cost, including outage time and frequency and parasitic load. Strategies for minimizing the impact to total generating cost while preserving system performance — generally referred to as catalyst management — are receiving greater attention. Approaches to managing catalyst can vary widely. Therefore, analysis of catalyst management strategies requires accurate predictive tools for assessing SCR system performance that have the flexibility to address a wide range of scenarios. These predictive tools may also be used to investigate performance issues that facility operators may encounter. However, until recently, operators have not had access to these tools, except through catalyst suppliers or consultants. In this presentation, various catalyst management strategies will be examined. Using an analysis tool recently adopted by several power plant operators and SCR technology suppliers, we will illustrate how such a tool can be used to optimize a catalyst management strategy to minimize the total cost of generation. Comparisons of model results to measured SCR performance at operating facilities will be presented. The model will be used to show operating trade offs for SCR operating parameters, such as NOx reduction, ammonia slip, catalyst outage frequency, catalyst usage, and parasitic load under a variety of scenarios. We will also discuss how the tool can be used to diagnose operating problems.

scholarly journals Coping with abrupt environmental change: the impact of the coastal El Niño 2017 on artisanal fisheries and mariculture in North Peru

2018 ◽  
Vol 76 (4) ◽  
pp. 1122-1130 ◽  
Author(s):  
Lotta Clara Kluger ◽  
Sophia Kochalski ◽  
Arturo Aguirre-Velarde ◽  
Ivonne Vivar ◽  
Matthias Wolff
Keyword(s):  
El Niño ◽  
El Nino ◽  
Management Strategies ◽  
Small Scale ◽  
Artisanal Fisheries ◽  
Economic Activities ◽  
Economic Sectors ◽  
Wide Range ◽  
The Impact ◽  
Coastal El Niño

Abstract In February and March 2017, a coastal El Niño caused extraordinary heavy rains and a rise in water temperatures along the coast of northern Peru. In this work, we document the impacts of this phenomenon on the artisanal fisheries and the scallop aquaculture sector, both of which represent important socio-economic activities for the province of Sechura. Despite the perceived absence of effective disaster management and rehabilitation policies, resource users opted for a wide range of different adaptation strategies and are currently striving towards recovery. One year after the event, the artisanal fisheries fleet has returned to operating almost on a normal scale, while the aquaculture sector is still drastically impacted, with many people continuing to work in different economic sectors and even in other regions of the country. Recovery of the social-ecological system of Sechura likely depends on the occurrence of scallop seed and the financial capacity of small-scale producers to reinitiate scallop cultures. Long-term consequences of this coastal El Niño are yet to be studied, though the need to develop trans-local and trans-sectoral management strategies for coping with disturbance events of this scale is emphasized.

Germination Biology of Sesbania (Sesbania cannabina): An Emerging Weed in the Australian Cotton Agro-environment

Weed Science ◽  
2018 ◽  
Vol 67 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Nadeem Iqbal ◽  
Sudheesh Manalil ◽  
Bhagirath S. Chauhan ◽  
Steve W. Adkins
Keyword(s):  
Seed Germination ◽  
Management Strategies ◽  
Moisture Stress ◽  
Integrated Weed Management ◽  
Burial Depth ◽  
Weed Species ◽  
Physical Dormancy ◽  
Sesbania Cannabina ◽  
Wide Range ◽  
The Impact

AbstractSesbania [Sesbania cannabina(Retz.) Pers.] is a problematic emerging weed species in Australian cotton-farming systems. However, globally, no information is available regarding its seed germination biology, and better understanding will help in devising superior management strategies to prevent further infestations. Laboratory and glasshouse studies were conducted to evaluate the impact of various environmental factors such as light, temperature, salt, osmotic and pH stress, and burial depth on germination and emergence of two Australian biotypes ofS. cannabina. Freshly harvested seeds of both biotypes possessed physical dormancy. A boiling-water scarification treatment (100±2 C) of 5-min duration was the optimum treatment to overcome this dormancy. Once dormancy was broken, the Dalby biotype exhibited a greater germination (93%) compared with the St George biotype (87%). The nondormant seeds of both biotypes showed a neutral photoblastic response to light and dark conditions, with germination marginally improved (6%) under illumination. Maximum germination of both biotypes occurred under an alternating temperature regime of 30/20 and 35/25 C and under constant temperatures of 32 or 35 C, with no germination at 8 or 11 C. Seed germination of both biotypes decreased linearly from 87% to 14% with an increase in moisture stress from 0.0 to −0.8 MPa, with no germination possible at −1.0 MPa. There was a gradual decline in germination for both biotypes when imbibed in a range of salt solutions of 25 to 250 mM, with a 50% reduction in germination occurring at 150 mM. Both biotypes germinated well under a wide range of pH values (4.0 to 10.0), with maximum germination (94%) at pH 9.0. The greatest emergence rate of the Dalby (87%) and St George (78%) biotypes was recorded at a burial depth of 1.0 cm, with no emergence at 16.0 cm. Deep tillage seems to be the best management strategy to stopS. cannabina’s emergence and further infestation of cotton (Gossypium hirsutumL.) fields. The findings of this study will be helpful to cotton agronomists in devising effective, sustainable, and efficient integrated weed management strategies for the control ofS. cannabinain cotton cropping lands.

Changes in Hospital Financing and Organization and Their Impact on Hospital Performance

2019 ◽  
Author(s):  
Jonas Schreyögg
Keyword(s):  
Financial Performance ◽  
Financial Incentives ◽  
Hospital Performance ◽  
Unintended Effects ◽  
Natural Experiments ◽  
Cross Sectional ◽  
Trade Offs ◽  
Wide Range ◽  
Improve Hospital ◽  
The Impact

Since the 1980s policymakers have identified a wide range of policy interventions to improve hospital performance. Some of these have been initiated at the level of government, whereas others have taken the form of decisions made by individual hospitals but have been guided by regulatory or financial incentives. Studies investigating the impact that some of the most important of these interventions have had on hospital performance can be grouped into four different research streams. Among the research streams, the strongest evidence exists for the effects of privatization. Studies on this topic use longitudinal designs with control groups and have found robust increases in efficiency and financial performance. Evidence on the entry of hospitals into health systems and the effects of this on efficiency is similarly strong. Although the other three streams of research also contain well-conducted studies with valuable findings, they are predominantly cross-sectional in design and therefore cannot establish causation. While the effects of introducing DRG-based hospital payments and of specialization are largely unclear, vertical and horizontal cooperation probably have a positive effect on efficiency and financial performance. Lastly, the drivers of improved efficiency or financial performance are very different depending on the reform or intervention being investigated; however, reductions in the number of staff and improved bargaining power in purchasing stand out as being of particular importance. Several promising avenues for future investigation are identified. One of these is situated within a new area of research examining the link between changes in the prices of treatments and hospitals’ responses. As there is evidence of unintended effects, future studies should attempt to distinguish between changes in hospitals’ responses at the intensive margin (e.g., upcoding) versus the extensive margin (e.g., increase in admissions). When looking at the effects of entering into a health system and of privatizations, there is still considerable need for research. With privatizations, in particular, the underlying processes are not yet fully understood, and the potential trade-offs between increases in performance and changes in the quality of care have not been sufficiently examined. Lastly, there is substantial need for further papers in the areas of multi-institutional arrangements and cooperation, as well as specialization. In both research streams, natural experiments carried out using program evaluation design are lacking. One of the main challenges here, however, is that cooperation and specialization cannot be directly observed but rather must be constructed based on survey or administrative data.

Modelling of the Selective Catalytic NOx Reduction for Diesel Engine

2011 ◽  
Vol 71-78 ◽  
pp. 2098-2102
Author(s):  
Hang Xu ◽  
Fang Yin Tu ◽  
Zhi Xia He ◽  
Jun Ma ◽  
Qian Wang
Keyword(s):  
Mathematical Model ◽  
Catalytic Reduction ◽  
Catalytic Converter ◽  
Nox Reduction ◽  
Space Velocity ◽  
Reaction Model ◽  
Future Emission ◽  
Emission Limits ◽  
The Impact ◽  
Good Agreement

As Future emission limits of diesel engines is more stringent, model-based control strategy of selective catalytic reduction (SCR) is becoming necessary. Therefore, a catalytic converter mathematical model for simulating selective catalytic deNOx reaction is very important. In this paper, a one dimension catalytic converter mathematical model that consists of thermal energy model, SCR reaction model and NH3storage model for simulating urea-SCR reaction process is presented. Based on this model, the impact of temperature and gas hourly space velocity (GHSV) on NOx conversion efficiency has been researched. According to the results of simulation, it shows good agreement with experimental data.

scholarly journals The EUA education policy: quality assurance strategies

Osvitolohiya ◽  
2017 ◽  
pp. 143-149 ◽  
Author(s):  
Iryna Sokolova ◽  
Keyword(s):  
Higher Education ◽  
Quality Assurance ◽  
Quality Management ◽  
Focal Point ◽  
Management Strategies ◽  
Reform Process ◽  
Policy Statement ◽  
Quality Culture ◽  
Wide Range ◽  
The Impact

The Bologna Reform Process, which became the focal point of reform in most European countries, brought a wide range of quality concerns into the central arena of higher education discourse. Quality Assurance processes were supposed to support an increased institutional attention. The aim of this paper is to create a better the EUA's Input to EHEA Policy Making. EUA carries out a variety of activities that are underpinned by the belief that the main responsibility for quality assurance lies within higher education institutions. EUA Policy Statement on Quality and Quality Assurance in the European Higher Education Area аre identified and described in the article.It is determined the impact of the EUA in shaping European quality culture through the development of educational policy and decision-conceptual documents, the annual European Quality Assurance Forums to consolidate internal and external stakeholders, expand the dialogue format in the context of the EHEA changing landscape and the best practices implementation for quality assurance. The keynote presentations of the EQAF (2006-2016) focused on current trends in quality assurance. The quality culture approach promoted by EUAdiffers clearly frommore traditional quality management strategies, shifting attention to more development-oriented and value-based aspects. Based on the results of the projects different approaches towards quality, quality culture, or formal quality assurance and accreditation procedures are focusedin the paper. The Institutional evaluation programme in higher education, realizedin 45 countries, is described. Other programs and projects that define the tasks of quality management are characterized in thepaper. Trends in quality assurance are presented in the article taking into account the national and European contexts. This paper outlines EUA key objectives for 2017-2019. Support the creation of thequality culture in higher education institutionsis one of them.

Selective Catalytic Reduction Impact on Heat Recovery Steam Generator Design and Operation

1986 ◽  
Author(s):  
James S. Davis ◽  
G. C. Duponteil
Keyword(s):  
Selective Catalytic Reduction ◽  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Gas Flow ◽  
High Efficiency ◽  
Catalytic Reduction ◽  
Nox Reduction ◽  
Heat Recovery Steam Generator ◽  
The Impact

Selective Catalytic Reduction (SCR) is a post-combustion method to reduce the oxides of nitrogen (NOx), present in flue gases such as gas turbine exhaust streams, to N2 and water. It involves the injection of ammonia and the use of a catalyst module to promote the reaction to obtain high efficiency (60–86+%) NOx reduction. Several operating parameters can influence catalyst performance to include temperature, gas flow distribution, presence of sulfur compounds and catalyst age. This paper examines the impact of a SCR integration in a gas turbine heat recovery steam generator (HRSG) design/operation. Limitations on HRSG load and following capabilities, effect on capital cost and overall performance and current SCR system experience represent a number of areas that are examined.

scholarly journals Water, Energy and Food Nexus in Rice Production in Thailand

2019 ◽  
Vol 11 (20) ◽  
pp. 5852 ◽  
Author(s):  
Pitak Ngammuangtueng ◽  
Napat Jakrawatana ◽  
Pariyapat Nilsalab ◽  
Shabbir H. Gheewala
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Rice Production ◽  
Analysis Tool ◽  
Production Sector ◽  
Trade Offs ◽  
The Impact ◽  
Resource Security

This research introduces an approach to analyze the nexus of water, energy and rice production system at the watershed scale. The nexus relationship equations, developed to suit the local scale facilitating analysis in the rice production sector, were integrated with a Material Flow Analysis tool to expand the visualization capability. Moreover, the nexus flow was linked with the selected resource security, eco-efficiency and economic indicators, taking into account the spatial and temporal effect of water availability. The study covers the nexus resource flows not only in the rice production sector but also all other sectors in the whole watershed to assess local resource security. The tool covers wider implications, trade-offs and synergy impacts that were not much covered in previous studies. The tool was applied to evaluate the trade-offs and synergies of the impacts from proposed scenarios of alternative agricultural practices and land-use change options. The scenarios applying land-use change, and changing non-suitable and low-suitable rice cultivation areas to sugarcane and cassava, can reduce water use significantly resulting in reducing the nexus energy while the impact on economics, food security and direct energy use is small.

scholarly journals Phenotypic Trade-Offs: Deciphering the Impact of Neurodiversity on Drug Development in Fragile X Syndrome

2021 ◽  
Vol 12 ◽  
Author(s):  
Truong An Bui ◽  
Julie Shatto ◽  
Tania Cuppens ◽  
Arnaud Droit ◽  
François V. Bolduc
Keyword(s):  
Clinical Trials ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
Single Gene ◽  
Specific Treatment ◽  
Autism Spectrum ◽  
New Paradigm ◽  
Trade Offs ◽  
Wide Range ◽  
The Impact

Fragile X syndrome (FXS) is the most common single-gene cause of intellectual disability and autism spectrum disorder. Individuals with FXS present with a wide range of severity in multiple phenotypes including cognitive delay, behavioral challenges, sleep issues, epilepsy, and anxiety. These symptoms are also shared by many individuals with other neurodevelopmental disorders (NDDs). Since the discovery of the FXS gene, FMR1, FXS has been the focus of intense preclinical investigation and is placed at the forefront of clinical trials in the field of NDDs. So far, most studies have aimed to translate the rescue of specific phenotypes in animal models, for example, learning, or improving general cognitive or behavioral functioning in individuals with FXS. Trial design, selection of outcome measures, and interpretation of results of recent trials have shown limitations in this type of approach. We propose a new paradigm in which all phenotypes involved in individuals with FXS would be considered and, more importantly, the possible interactions between these phenotypes. This approach would be implemented both at the baseline, meaning when entering a trial or when studying a patient population, and also after the intervention when the study subjects have been exposed to the investigational product. This approach would allow us to further understand potential trade-offs underlying the varying effects of the treatment on different individuals in clinical trials, and to connect the results to individual genetic differences. To better understand the interplay between different phenotypes, we emphasize the need for preclinical studies to investigate various interrelated biological and behavioral outcomes when assessing a specific treatment. In this paper, we present how such a conceptual shift in preclinical design could shed new light on clinical trial results. Future clinical studies should take into account the rich neurodiversity of individuals with FXS specifically and NDDs in general, and incorporate the idea of trade-offs in their designs.

scholarly journals Etiology, diagnostic approaches and management strategies of Acidovorax citrulli, a bacterial fruit blotch pathogen of cucurbits

2021 ◽  
Vol 57 (No. 2) ◽  
pp. 75-94
Author(s):  
Ainur Ainiah Azman Husni ◽  
Siti Izera Ismail ◽  
Noraini Jaafar ◽  
Dzarifah Zulperi
Keyword(s):  
Control Strategies ◽  
Management Strategies ◽  
Characterization Methods ◽  
Bacterial Fruit Blotch ◽  
Acidovorax Citrulli ◽  
Group I ◽  
Wide Range ◽  
Research Findings ◽  
Management Approaches ◽  
The Impact

Bacterial fruit blotch (BFB) caused by Acidovorax citrulli, represents one of the most destructing diseases of cucurbits, especially to watermelon- and melon producing-regions. This disease has been spread sporadically to many countries globally, due to the unintentionally dispersal of contaminated commercial seeds. The BFB causes massive yield losses up to 100% under conducive conditions. Once infected, all parts of the host plants are extremely susceptible to this bacterium, especially the seedlings and fruits parts. In recent years, various management approaches and detection tools have been employed to control A. citrulli. Genotypic characterization methods revealed two distinct groups of A. citrulli strains; (i) group I strains primarily isolated from non-watermelon cucurbits and consist of moderate to highly aggressive strains from wide range of cucurbit hosts, and (ii) group II strains isolated from watermelon which are highly aggressive on watermelon, but mildly aggressive on non-watermelon hosts. In this paper, an attempt has been made to review research findings where the impact of diverse methods and management approaches were applied in detection and controlling of A. citrulli infection. A better understanding of this devastating bacterium will serve as guidelines for agricultural practitioners in developing the most efficient and sustainable BFB control strategies.

scholarly journals The Cascade Analysis Tool: software to analyze and optimize care cascades

2019 ◽  
Vol 3 ◽  
pp. 1488 ◽  
Author(s):  
David J Kedziora ◽  
Romesh Abeysuriya ◽  
Cliff C Kerr ◽  
George L Chadderdon ◽  
Vlad-Ștefan Harbuz ◽  
...  
Keyword(s):  
Cost Effective ◽  
Optimization Methods ◽  
Successful Outcome ◽  
Analysis Tool ◽  
Software Application ◽  
Wide Range ◽  
Cascade Analysis ◽  
Health And Development ◽  
Advanced Analysis ◽  
The Impact

Introduction: Cascades, which track the progressive stages of engagement on the path towards a successful outcome, are increasingly being employed to quantitatively assess progress towards targets associated with health and development responses. Maximizing the proportion of people with successful outcomes within a budget-constrained context requires identifying and implementing interventions that are not only effective, but also cost-effective. Methods: We developed a software application called the Cascade Analysis Tool that implements advanced analysis and optimization methods for understanding cascades, combined with the flexibility to enable application across a wide range of areas in health and development. The tool allows users to design the cascade, collate and enter data, and then use the built-in analysis methods in order to answer key policy questions, such as: understanding where the biggest drop-offs along the cascade are; visualizing how the cascade varies by population; investigating the impact of introducing a new intervention or scaling up/down existing interventions; and estimating how available funding should be optimally allocated among available interventions in order to achieve a variety of different objectives selectable by the user (such as optimizing cascade outcomes in target years). The Cascade Analysis Tool is available via a user-friendly web-based application, and comes with a user guide, a library of pre-made examples, and training materials. Discussion: Whilst the Cascade Analysis Tool is still in the early stages of existence, it has already shown promise in preliminary applications, and we believe there is potential for it to help make sense of the increasing quantities of data on cascades.

Sign in / Sign up

Export Citation Format

Share Document