Hybrid nuclear-solar power

Nuclear and solar power, in the form of concentrated solar power (CSP), play a significant role in achieving the ambitious global targets of reducing greenhouse emissions and guaranteeing security of energy supply. However, both power generation technologies still require further development to realise their full potential, especially in terms of attaining economic load following operations and higher thermal efficiencies. Therefore, the aim of this research is to investigate and thermo-economically evaluate the available options of upgrading the flexibility and enhancing the thermal efficiency of nuclear and solar power generation technologies (i.e., through the integration with thermal energy storage (TES) and by hybridising both power generation technologies) while providing reasonable economic returns. The thesis starts with describing the development and validation of several thermodynamic and economic computational models and the formulation of the whole-energy system model. The formulated models are utilised to perform several thermo-economic studies in the field of flexible nuclear and solar power, and to quantify the economic benefits that could result from enhancing the flexibility of nuclear power plants from the whole-energy system perspective. The studies conducted in this research are: (i) a thermo-economic assessment of extending the conventional TES system in direct steam generation (DSG) CSP plants; (ii) a thermo-economic evaluation of upgrading the flexibility of nuclear power plants by the integration with TES and secondary power generation systems; (iii) an investigation of the role of added flexibility in future low-carbon electricity systems; and (iv) a design and operation analysis of a hybrid nuclear-solar power plant. The most common TES option in DSC CSP plants is steam accumulation. This conventional option is constrained by temperature and pressure limits, leading to lower efficiency operations during TES discharging mode. Therefore, the option of integrating steam accumulators with sensible-heat storage in concrete to provide higher-temperature superheated steam is thermo-economically investigated in this research, taking an operational DSG CSP plant as a case study. The results show that the integrated concrete-steam TES (extended) option delivers 58% more electricity with a 13% enhancement in thermal efficiency during TES discharging mode, compared to the conventional steam accumulation (existing) configuration. With an estimated additional investment of $4.2M, the projected levelised cost of electricity (LCOE) and the net present value (NPV) for the considered DSG CSP plant with the extended TES option are respectively 6The option of upgrading the flexibility of nuclear power plants through the integration with TES and secondary power generation systems is investigated for two conventional nuclear reactors, a 670-MWel advanced gas-cooled reactor (AGR) and a 1610-MWel European pressurised reactor (EPR). In both investigated case studies, the reactors are assumed to continuously operate at full rated thermal power, while load following operations are conducted through the integrated TES tanks and secondary power generators. Based on the designed TES and secondary power generation systems, the AGR-based configuration can modulate the power output between 406 MWel and 822 MWel, while the EPR-based configuration can operate flexibly between 806 MWel and 2130 MWel. The economic analysis results demonstrate that the economics of added flexibility are highly dependent on: (i) the size of the TES and the secondary power generation systems; (ii) the number of TES charge/discharge cycles per day; and (iii) the ratio and difference between off-peak and peak electricity prices. Replacing conventional EPR-based nuclear power plants with added flexibility ones is found to generate whole-system cost savings between$30.4M/yr and $111M/yr. At an estimated cost of added flexibility of$53.4M/yr, the proposed flexibility upgrades appear to be economically justified with net system economic benefits ranging from $5.0M/yr and$39.5M/yr for the examined low-carbon scenarios, provided that the number of flexible nuclear plants in the system is small. The concept of hybridising a small modular reactor (SMR) with a solar-tower CSP integrated with two-tank molten salt TES system, with the aim of achieving economically enhanced load following operations and higher thermal efficiency levels, is also thermo-economically investigated in this research. The integration of both technologies is achieved by adding a solar-powered superheater and a reheater to a standalone SMR. The obtained results demonstrate that hybridising nuclear and solar can offer a great amount of flexibility (i.e., between 50% and 100% of nominal load of 131 MWel) with the SMR continuously operated at full rated thermal power output. Furthermore, the designed hybrid power plant is able to operate at higher temperatures due to the addition of the solar superheater, resulting in a 15% increase of thermal efficiency compared to nuclear-only power plant. Moreover, the calculated specific investment cost and the LCOE of the designed hybrid power plant are respectively 5410 $/kWel and 77$/MWhel, which are 2% and 4% lower than those calculated for the nuclear-only power plant.Open Acces

Press Freedom and Corruption in the GCC: Are There Better Future Horizons? An Analytical-Critical Study

This study seeks to provide a critical analysis of press freedom and corruption scores in the six Arab countries under the Gulf Cooperation Council (GCC), as reported by two international nongovernmental organizations 2013–2017: (1) Freedom House (FH) and (2) Transparency International (TI). The researcher noted how some of the reports by these organizations continually connect between press freedom and corruption. The reading might help to improve the GCC states’ future performances both in press freedom and fighting against corruption. Readings on press freedom and corruption are now more widely available in many international reports of a number of international organizations. Although standards for measuring the degree of both of them vary in these reports, they often agree on one outcome. Some of these reports have gradually gained prominence in good segments of public opinion and have become the subject of debate among intellectuals and journalists. Governments refrain from commenting on such reports particularly negative ones. However, the impact of such reports on the relevant governmental entities cannot be ignored when it comes to calibrating their practices and activities internationally and comparing them with other institutions in other regional and global countries

Characteristics of the Editorial and Advertisement Content of the Omani Arabic Dailies Front Page: A Study on Content and Communicator

This study aims to identify the characteristics of the editorial and advertisement content of the Omani Arabic dailies front page. It explores the characteristics and attitudes of front page editors and journalists. The study adopts a media survey methodology and uses content analysis in addition to the unstructured interview to study both the editorial and advertisement contents. The study also studies the nature of the editorial policies affecting content published in the front page of the newspapers in question. The results reveal the dominance of editorial content over advertisement content in the front page, with 67% for editorial content, and only 33% for advertisement content. The study shows that private newspapers are more interested in advertisement content than public newspapers. The results also indicate that newspapers rely on their own sources in gathering news for the front page. The study shows that 4% of the news published on the front page appeared with anonymous sources

Journalists in the Sultanate of Oman and Social Media: Survey Study on Uses and Challenges

This study aims to identify the extent of using social media among journalists in the Omani Arabic dailies, understand and recognize the connection of using social media in workplace as well as to identify the challenges that might affect journalists use of social media. The study adopting a descriptive survey method to all the data through formalization and distribution of questionnaires. The sample of this study is comprises of (176) journalists who are working in daily newspapers in the Sultanate of Oman namely: Alwatan, Oman, Al Shabiba, AZamn and Al roya. The study concludes a set of results; most notablythose respondents are mostly preferring use Twitter, whereas the smart phones are mostly used by respondents to access social media. While Respondents mostly prefer to login to social media from home, one thirty of respondents are spend one to two hours using social media. The study also shows that social topics came on the top in the terms of sharing and following by the respondents. Furthermore, the study shows there were no any training courses about how to deal with these social media. The results confirmed that only 26% of the respondents had specialized training in social media. This is beside the significant occupational burdens, the lack of devices with programs and the absence of Wi-Fi networks as main and prominent challenges that have been stated by the respondents, which reduce the benefit of these social media

Blalock-Taussig Shunt versus Ductal Stenting as Palliation for Duct-Dependent Pulmonary Circulation

Objectives: There is limited data published from outside North America and Europe comparing the outcomes of a modified Blalock-Taussig shunt (MBTS) and ductal stenting as the first palliative procedure for infants with duct-dependent pulmonary circulation. This study reports the National Heart Center’s, in Muscat, Oman, experience in comparing the outcomes of these 2 interventions. Methods: This retrospective study included all infants with duct-dependent pulmonary circulation who received either a MBTS or ductal stenting from 2016–2019. The primary outcomes were death or re-interventions. Secondary outcomes included death, subsequent re-interventions, survival to subsequent surgical intervention, survival to hospital discharge, post-procedural mechanical ventilation and duration of intensive care unit stay. Results: A total of 71 patients were included in the study, 33 (46%) of whom received ductal stenting. The prevalence of the primary outcome (death or re-intervention) in the patent ductus arteriosus (PDA) stent group was 54.5% versus 31.6% in the MBTS group but this was not statistically significant (P = 0.06). There was no difference between the 2 groups in terms of time to next surgical intervention (P = 0.233). The PDA stent group had shorter post-procedural, mechanical ventilation and intensive care unit stay durations (P <0.05). Syndromic patients were at higher risk of mortality compared to non-syndromic patients. Conclusion: MBTS and ductal stenting are both acceptable modalities as a palliative intervention for infants with duct-dependant pulmonary circulation. Syndromic patients are at higher risk of mortality. This can be considered an important factor for patient selection. Keywords: Blalock-Taussig Procedure; Patent Ductus Arteriosus; Pulmonary Atresia; Oman

Table 2: Example applications of the use of remote sensing technologies to detect change in vegetation.

In order to understand the distribution and prevalence of Ommatissus lybicus (Hemiptera: Tropiduchidae) as well as analyse their current biographical patterns and predict their future spread, comprehensive and detailed information on the environmental, climatic, and agricultural practices are essential. The spatial analytical techniques such as Remote Sensing and Spatial Statistics Tools, can help detect and model spatial links and correlations between the presence, absence and density of O. lybicus in response to climatic, environmental, and human factors. The main objective of this paper is to review remote sensing and relevant analytical techniques that can be applied in mapping and modelling the habitat and population density of O. lybicus. An exhaustive search of related literature revealed that there are very limited studies linking location-based infestation levels of pests like the O. lybicus with climatic, environmental, and human practice related variables. This review also highlights the accumulated knowledge and addresses the gaps in this area of research. Furthermore, it makes recommendations for future studies, and gives suggestions on monitoring and surveillance methods in designing both local and regional level integrated pest management strategies of palm tree and other affected cultivated crops

The role of information professionals in global economic crisis

It is now generally agreed that better information use in the financial services sector might have helped to avert the economic crisis which originated in the U.S. in 2007. Similarly, it is clear that improved availability and communication of good information could have helped prevent the types of consumer and investor reactions which spread the crisis around the globe today. Drawing on a range of existing sources, this paper considers the impact of information failure and the role of information professionals in the economic crisis. It then examines how information professionals can make an important contribution to economic recovery and sets out recommendations for the profession. The paper concludes that unless information professionals play a more proactive role in making good economic and financial information readily accessible, the risk of recurrent economic crises will be increased