270 research outputs found
Future District Heating Interactions – Modelling Impacts of Industrial Excess Heat Utilisation and Energy Efficient Buildings [Elektronisk resurs]
No full textInternational goals for climate change mitigation plus energy security targets could be met cost-effectively by interactions between different parts of energy systems. The fourth generation of the district heating systems concept was developed as an attempt to accelerate district heating (DH) systems’ interactions with other energy systems. This thesis investigates future interactions of district heating (DH) systems with industries and buildings. This is investigated by developing a methodology and applying it to real cases. Taking a long-term and system-wide perspective, the investigation includes carbon (CO2) and techno-economic impacts of increased energy efficiency in industries and buildings on the DH systems. Real case studies are selected to capture the local conditions of DH systems. Climate policy scenarios are designed as the starting point for the investigations and systematic sensitivity analyses are designed to test the robustness of the case study results. The tool applied is dynamic energy systems optimisation modelling. A regional MARKAL model is applied for DH-industry interactions, whereas a local TIMES model is applied for DH-building interactions. The heating sector and parts of the electricity, transport, industry and building sectors are represented in the optimisation models. The results show that, through a large heat network allowing for long transmission of industrial excess heat (EH) to DH systems, the DH-industry interaction requires major investment. Such investment is likely to be profitable if the EH replaces DH (which is primarily supplied by costly primary energy sources). From a systems perspective, the investment is less likely to be profitable if other EH sources contribute a large share of the DH base load and if there is an abundance of locally available, low-cost biomass. If built, heat networks help reduce biomass and fossil fuel use and provide a related reduction in CO2 emissions in DH systems. This outcome implies decreased electricity generation from combined heat and power (CHP) plants, in the region studied. In low-energy building (LEB) areas, DH-building interactions (using a heat connection which allows heat to be supplied from a nearby urban area DH system to an LEB area) are cost-effective relative to local (on-site) DH and individual heat supply options. However, changes in energy flows (and CO2 emissions resulting from the nearby urban area DH systems) depend on assumptions about future climate policies, marginal electricity generation and alternative use of biomass, as well as the scale of the urban area DH system
Large Heat Networks in District Heating Systems
No full textDistrict heating (DH) systems have experienced three generations since the 1880s. In chronological order, high temperature steam and pressurized hot water above and below 100 degrees have been used to carry heat over these three generations. The drive to increase energy efficiency and reduce investment costs of these systems have been the principal incentives for shifting from one generation to the other. The future development of DH systems towards the fourth generation will involve an attempt to recover heat from low-temperature sources (e.g. industrial excess heat (EH)), the use of renewable sources and the integration into smart energy systems. In Sweden, DH currently supplies about 60% of the heat demand. For future DH developments, these systems need to be competitive compared to individual solutions (i.e. heat pumps and boilers) in supplying heat. They could also be incorporated in future sustainable energy systems by integrating renewables and establishing synergies with other energy sectors. There are currently some successful synergies between industry and DH systems but as one step towards the fourth generation of DH, industry-DH synergies could be further developed in order to recover still unused industrial EH. Due to the diversity of Swedish DH systems in terms of local fuel use and heat demand, their choice of heat production technologies is affected. Thus, the environmental and economic impacts of DH systems-industry synergies that allow for industrial EH use in DH systems or the DH use in industrial processes have often been studied in a small geographical scale, limited to the boundaries of local DH systems. However, because it is often transported over relatively short distances, biomass as the main fuel used in DH systems has often turned into a regional market. With increasingly stringent targets for climate change mitigation, biomass use is likely becoming more attractive not only in the heat but also in the power and transport sectors. Since synergies between local DH systems and industry affect the regional market for biomass and, consequently, the power and transport sectors, a regional level combined with an inter-sectoral approach might provide a comprehensive way to identify the impacts of DH-industry synergies.The aims of this thesis are, first, to develop a methodology for assessing an option for future DH development, i.e. a large heat network that would allow for long-distance industrial EH transmission for use in DH systems; and, second, to apply this methodology to assess energy systems, environmental and economic impacts of a large heat network between the cluster of chemical industries in Stenungsund and the DH systems of Gothenburg and Kung\ue4lv in West Sweden Region (V\ue4stra G\uf6taland (VG)). The assessment has been carried out with the help of optimizing energy systems model MARKAL_WS, in which the DH systems in the VG Region are represented individually. In addition, options for transport biofuel production as competitors to regional biomass are included. The thesis is based upon two papers. In the first paper, energy system and CO2 emission impacts of the large heat network have been analyzed at a regional level. The results show that the heat network contributes to a reduction of biomass and fossil fuel use, and to a related reduction of CO2 emissions, in the DH systems. This outcome opens opportunities for the earlier production of transport biofuels but implies decreased electricity generation from combined heat and power (CHP) plants in the Region. In the short-term, total CO2 emissions increase, given an expanded systems view that effects on the DH systems, transport and European electricity system are accounted for, while in the mid-term they decrease.In the second paper, the long-term system cost and marginal cost effects of the large heat network have been assessed. The results show that the heat network is profitable under most assumptions and that the profitability increases with biomass competition and the phase-out of fossil fuel use while it decreases with higher CO2 charge, interest rates and the availability of other EH sources in the vicinity of the DH systems. The marginal cost of DH supply in the Gothenburg and Kung\ue4lv DH systems decreases during most seasons except for the cold seasons
Large Heat Networks in District Heating Systems [Elektronisk resurs]
No full textDistrict heating (DH) systems have experienced three generations since the 1880s. In chronological order, high temperature steam and pressurized hot water above and below 100 degrees have been used to carry heat over these three generations. The drive to increase energy efficiency and reduce investment costs of these systems have been the principal incentives for shifting from one generation to the other. The future development of DH systems towards the fourth generation will involve an attempt to recover heat from low-temperature sources (e.g. industrial excess heat (EH)), the use of renewable sources and the integration into smart energy systems. In Sweden, DH currently supplies about 60% of the heat demand. For future DH developments, these systems need to be competitive compared to individual solutions (i.e. heat pumps and boilers) in supplying heat. They could also be incorporated in future sustainable energy systems by integrating renewables and establishing synergies with other energy sectors. There are currently some successful synergies between industry and DH systems but as one step towards the fourth generation of DH, industry-DH synergies could be further developed in order to recover still unused industrial EH. Due to the diversity of Swedish DH systems in terms of local fuel use and heat demand, their choice of heat production technologies is affected. Thus, the environmental and economic impacts of DH systems-industry synergies that allow for industrial EH use in DH systems or the DH use in industrial processes have often been studied in a small geographical scale, limited to the boundaries of local DH systems. However, because it is often transported over relatively short distances, biomass as the main fuel used in DH systems has often turned into a regional market. With increasingly stringent targets for climate change mitigation, biomass use is likely becoming more attractive not only in the heat but also in the power and transport sectors. Since synergies between local DH systems and industry affect the regional market for biomass and, consequently, the power and transport sectors, a regional level combined with an inter-sectoral approach might provide a comprehensive way to identify the impacts of DH-industry synergies.The aims of this thesis are, first, to develop a methodology for assessing an option for future DH development, i.e. a large heat network that would allow for long-distance industrial EH transmission for use in DH systems; and, second, to apply this methodology to assess energy systems, environmental and economic impacts of a large heat network between the cluster of chemical industries in Stenungsund and the DH systems of Gothenburg and Kungälv in West Sweden Region (Västra Götaland (VG)). The assessment has been carried out with the help of optimizing energy systems model MARKAL_WS, in which the DH systems in the VG Region are represented individually. In addition, options for transport biofuel production as competitors to regional biomass are included. The thesis is based upon two papers. In the first paper, energy system and CO2 emission impacts of the large heat network have been analyzed at a regional level. The results show that the heat network contributes to a reduction of biomass and fossil fuel use, and to a related reduction of CO2 emissions, in the DH systems. This outcome opens opportunities for the earlier production of transport biofuels but implies decreased electricity generation from combined heat and power (CHP) plants in the Region. In the short-term, total CO2 emissions increase, given an expanded systems view that effects on the DH systems, transport and European electricity system are accounted for, while in the mid-term they decrease.In the second paper, the long-term system cost and marginal cost effects of the large heat network have been assessed. The results show that the heat network is profitable under most assumptions and that the profitability increases with biomass competition and the phase-out of fossil fuel use while it decreases with higher CO2 charge, interest rates and the availability of other EH sources in the vicinity of the DH systems. The marginal cost of DH supply in the Gothenburg and Kungälv DH systems decreases during most seasons except for the cold seasons
Future District Heating Interactions – Modelling Impacts of Industrial Excess Heat Utilisation and Energy Efficient Buildings
No full textInternational goals for climate change mitigation plus energy security targets could be met cost-effectively by interactions between different parts of energy systems. The fourth generation of the district heating systems concept was developed as an attempt to accelerate district heating (DH) systems’ interactions with other energy systems. This thesis investigates future interactions of district heating (DH) systems with industries and buildings. This is investigated by developing a methodology and applying it to real cases.Taking a long-term and system-wide perspective, the investigation includes carbon (CO2) and techno-economic impacts of increased energy efficiency in industries and buildings on the DH systems. Real case studies are selected to capture the local conditions of DH systems. Climate policy scenarios are designed as the starting point for the investigations and systematic sensitivity analyses are designed to test the robustness of the case study results. The tool applied is dynamic energy systems optimisation modelling. A regional MARKAL model is applied for DH-industry interactions, whereas a local TIMES model is applied for DH-building interactions. The heating sector and parts of the electricity, transport, industry and building sectors are represented in the optimisation models. \ua0The results show that, through a large heat network allowing for long transmission of industrial excess heat (EH) to DH systems, the DH-industry interaction requires major investment. Such investment is likely to be profitable if the EH replaces DH (which is primarily supplied by costly primary energy sources). From a systems perspective, the investment is less likely to be profitable if other EH sources contribute a large share of the DH base load and if there is an abundance of locally available, low-cost biomass. If built, heat networks help reduce biomass and fossil fuel use and provide a related reduction in CO2 emissions in DH systems. This outcome implies decreased electricity generation from combined heat and power (CHP) plants, in the region studied. In low-energy building (LEB) areas, DH-building interactions (using a heat connection which allows heat to be supplied from a nearby urban area DH system to an LEB area) are cost-effective relative to local (on-site) DH and individual heat supply options. However, changes in energy flows (and CO2 emissions resulting from the nearby urban area DH systems) depend on assumptions about future climate policies, marginal electricity generation and alternative use of biomass, as well as the scale of the urban area DH system
The Reflection of Islamic Culture and Beliefs in the Stories of Dr. Akram Osman
No full textThe sacred religion of Islam encompasses its own distinct principles, laws, and worldview, as presented through the Holy Quran, a divine guide for humanity. This guidance shapes the beliefs, actions, and morals of Muslims according to an Islamic perspective. Islam is a comprehensive and complete religion that addresses all aspects of individual, familial, social, economic, political, and cultural life. It provides everything necessary for human guidance and prosperity, as conveyed to humanity by Prophet Muhammad (PBUH), the savior of mankind, who is the final prophet, and Islam is the ultimate and final religion. In Islamic societies, the responsibility of promoting and conveying Islamic teachings was not limited to religious scholars alone. Muslim poets and writers also undertake this significant mission, using their literary talents in both poetry and prose to inspire individuals and societies with the values and teachings of this sacred religion. The late Dr. Mohammad Akram Osman, a distinguished author from Afghanistan, made remarkable contributions to storytelling that not only enriched the world of literature but also served as a guide for humanity in learning and understanding Islamic culture and beliefs. This article aims to explore the reflection of Islamic culture and beliefs in the stories of Dr. Mohammad Akram Osman, highlighting his ability to intertwine Islamic teachings with literary expression
Neutralisation state driven single-agent search strategy for solving constraint satisfaction problem / Saajid Akram Ahmed Abuluaih
No full textIn the past seven decades, Constraint Satisfaction (CS) has been extensively studied and remarkably evolved to where the scientific community perceives it as the centre of the intelligent behaviour. Therefore, most of the recent research in the field is devoted to improving the problem solvers that utilize search strategies and techniques. Since Constraint Satisfaction Problem (CSP) is an NP-complete problem, brute-force search algorithms such as Backtracking algorithm (BT) are required as the guarantee to find a solution, when there is one. Moreover, since the establishment of the field, AI pioneers and specialists have setup instructions and guidelines on how to solve this type of problems back in the seventies of the last century and have not been changed or improved. For example, the framework of solving CSP imposes a complete permutation of assignments to all remaining variables in order to derive a valid model. The author argues in this study that the problem can be neutralised and it is not necessary to perform brute-force searching all the time if a search strategy could have guided the process to the level where the values of the remaining variables can be determined implicitly, creating what the author calls Solo-Path of assignments in the problem search tree
System profitability of excess heat utilisation – A case-based modelling analysis
No full textAbstractThe use of EH (excess heat) in DH (district heating) may contribute to increased sustainability through reduced use of primary energy. In Sweden, while biomass has become the most important DH fuel during the last decades, there is a significant amount of industrial EH that could be utilised in the DH systems if it could be shown to be an economically viable alternative. This study addresses the long-term system profitability of a large heat network between a cluster of chemical industries and two DH systems that enables an increased use of EH. An assessment is carried out by scenario and sensitivity analyses and by applying the optimising energy systems model MARKAL_WS, in which the DH systems of the Västra Götaland region of Sweden are represented individually. The results show heat network profitability under most assumptions, and that the profitability increases with biomass competition, phase-out of natural gas use and higher CO2 charges, whereas it decreases with the availability of other EH sources in the base load of the DH systems
Low-energy buildings heat supply–Modelling of energy systems and carbon
No full textConstruction of new low-energy buildings (LEB) areas is attracting attention as a climate mitigation measure.Heat can be supplied to buildings in these areas through individual solutions, through a small, on-site heatnetwork, or through a heat connection to a close-by district-heating (DH) system. The choice between theseoptions affects the energy supply systems and their carbon emissions far beyond the LEB area. We compare thelong-term systems impacts of the three heat-supply options through dynamic modelling of the energy systems.The study draws on data collected from a real LEB area in Sweden and addresses scale-dependent impacts ondistrict heating systems. The results show that, generally, the individual and on-site options increase biomassand electricity use, respectively. This, in turn, increases carbon emissions in a broader systems perspective. Thesystems impacts of the large heat network option depend on the scale and supply-technologies of the DH systemclose to the LEB area
Clinical characteristics of critically ill patients infected with COVID-19 in rasoul akram hospital in Iran: A single center study
No full textBackground: Knowledge about clinical features of critically ill patients with COVID-19 still lacks adequate information up to now. Objectives: We aimed to describe and compare the epidemiological and clinical characteristics of critically ill patients with COVID-19 in Rasoul Akram Hospital. Methods: In this case series, 70 critically ill patients with COVID-19 admitted in ICU wards of Rasoul Akram Hospital, Tehran, Iran, from 29 February to 25 April 2020 were enrolled. Demographic and clinical characteristics, laboratory data, and outcomes of the patients were all collected and compared between deceased and recovered patients. Results: Fifty-six cases had died of COVID-19, and 14 patients had fully recovered and discharged. The median age of the patients was 68 years old, ranging from 22 to 91 years, 66 were men, 80 had one or more comorbidities, and hypertension was the most common comorbidities (45 of deceased cases). The most common signs and symptoms at the onset of illness were SPO2 depression (92) and dyspnea (90). Dyspnea was significantly more common in deceased patients (95) than recovered patients (70) (P = 0.048). Most patients had lymphopenia (80). The number of patients who needed mechanical ventilation in the deceased patients was 53 (95), which was significantly more than the recovered patients (10 70%) (P = 0.048). Conclusions: The mortality rate of critically ill patients with COVID-19 is very high, and the patients with dyspnea and required mechanical ventilation are at higher risk for death. © 2020, Author(s)
Akram Khan, Lloyd Newson, and the Challenges of British Multiculturalism
No full textIn a climate riven by national insecurities, anti-immigration movements and competing visions of a post-Brexit future, this paper examines the contentious space multiculturalism has inhabited in 21st-century British choreography. It analyses acclaimed works by Akram Khan and Lloyd Newson to explore starkly differing perspectives on cultural diversity in the UK. Khan’s contribution to the London 2012 Olympics Opening Ceremony (Abide with Me) emphasised the nation’s post-imperialist and cosmopolitan profile. By contrast, Newson’s contemporaneous work Can We Talk about this? (2011/12) was highly critical of current models of multiculturalism and in particular attitudes towards Islam. This paper compares the two choreographies using a theoretical framework that draws on both political thought and dance analysis, to evaluate their contributions to debates around culture, tolerance and diasporic identities and illustrate the broader entanglement between British dance and contemporary politics.@ 2018, Edinburgh University Press. The attached document is an author produced version of a paper accepted for publication in Dance Research, uploaded in accordance with the publisher’s self-archiving policy. Some minor differences between this version and the final published version may remain. Once published, we suggest you refer to the final published version (Version of Record) should you wish to cite from it
- …
