Underground hydrogen storage : exploring geochemistry, cushion gas dynamics, and techno-economy for sustainable energy solutions

Hydrogen holds significant promise as a critical player in the energy transition due to its versatility and low lifecycle carbon emissions. Its superior energy content per unit mass positions hydrogen as a compelling alternative to natural gas, making it a reliable and efficient energy carrier. Facilitating a practical storage solution is pivotal in advancing the transition to hydrogen energy. Utilizing subsurface reservoirs and saline aquifers to store hydrogen allows for efficient long-term storage, balancing energy supply and demand, especially during intermittent renewable energy generation. However, the unique physical and chemical properties of hydrogen—its high reactivity, buoyancy, and flammability—pose significant challenges for geological storage. Dedicated research is essential to unravel the complex mechanisms inherent in UHS. The primary focus of this dissertation is the quantification and mitigation of hydrogen loss, which can occur through physical entrapment or chemical consumption. To address these challenges, this study aims to advance the knowledge of the suitability of saline aquifers for UHS by developing a robust simulation framework. This framework is designed to capture the complexities of underground storage through field-scale numerical simulations that incorporate various physical processes such as fluid flow and chemical reactions. The results revealed that the impact of wettability on storage efficiency is minimal, while hysteresis significantly affects hydrogen recovery, causing a notable decrease from 78% to 45% by the fourth cycle when gas hysteresis is considered; however, recovery improves with prolonged production until depletion. Optimal cushion gases for maximizing hydrogen recovery are CH₄ and N₂. The study also highlighted the benefits of using alternative cushion gases in reducing H₂S generation and the substantial hydrogen loss due to the methanation reaction. However, N₂ is recommended over CH₄ as a cushion gas due to its lower cost, abundant availability, and ease of achieving acceptable purity levels for hydrogen applications. A central contribution of this work is the development of novel methods to accurately model hydrogen behavior in saline aquifers. This includes improving the simulation capability for predicting hydrogen recovery—a critical aspect of UHS—through the interpolation of relative permeability curves to accurately account for gas flow. Additionally, the fluid model is accurately tuned to match laboratory data for gas mixtures, and a reactive transport model is developed based on experimental data and reaction kinetics. Given the critical role of cushion gas in storage projects, this research also thoroughly evaluates three alternative options besides hydrogen. Each option's efficacy in containing hydrogen, preventing physical loss, ensuring geochemical safety, and determining economic viability is assessed. Our evaluation encompasses detailed analyses of gas properties, interactions with reservoir formations, and long-term stability under operational conditions. Based on these comprehensive assessments, we provide final recommendations aimed at optimizing UHS in saline aquifers, offering valuable insights and technical guidance to the industry.Petroleum and Geosystems Engineerin

Assistive Technology Use for Students with Down syndrome at Mainstream Schools in Riyadh, Saudi Arabia: Teachers’ Perspectives

In this study, the researcher sought to examine the teachers’ Attitudes on use of assistive technology for Students with Down syndrome in Riyadh, Saudi Arabia. The study undertook literature review and survey in order to answer the research questions that had been formulated. The survey involved 50 teachers who had been selected form teachers teaching students with down syndrome in schools located in Riyadh, Saudi Arabia. The results from the survey and from the literature review indicate that teachers have positive attitudes the use of assistive technology. Teachers felt that assistive technology is a good tool that assists children with Down syndrome in their learning activities and even social activities.  When they use assistive technology, teachers reported that assistive technology was an effective tool in improving literacy among these children. Still, teachers as well reported that there are several barriers towards the use of assistive technology. These barriers include, lack of training or skills, lack of support, lack of enough resources and lack of time.  The teachers felt that there was need to provide more training and to include assistive training in school curriculum. The study concluded that use of assistive technology is supported by teachers and therefore enough support should be given to theme for better outcome in use of assistive technology. Keywords: Assistive technology, Down syndrome (DS) and teachers’ Attitude

Factors affecting e-Government implementation and adoption in the State of Qatar

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Electronic government (e-government) has established as an effective mechanism for increasing government productivity and efficiency and a key enabler of citizen-centric services. However, e-government implementation is surrounded by organisational, technological, political and social issues, which have to be considered and treated carefully in order to facilitate this change. Conversely, from an adoption perspective, e-government services are yet to be universally accepted as a medium for accessing online public services since its inception more than a decade ago. In terms of prior research into understanding the implementation challenges and adoption factors, most existing literature focus into either the implementation context or adoption context separately and no research studies were found that take a holistic viewpoint of both implementation and adoption. Furthermore, only a few researchers have explored and reflected on the important factors that can impact e-government implementation using well founded theoretical models or frameworks. Besides, there is no universal model for e-government implementation and adoption that is applicable for all countries to ensure success, especially for developing and Gulf Cooperation Countries (GCC). Therefore, this thesis attempts to explore and investigate the key challenges that influence e-government implementation and the factors influencing citizen adoption in the state of Qatar. By simultaneously analysing and aligning the implementation issues of e-government with the adoption aspects, this study aimed to develop a better understanding of the gaps that exists between implementation and adoption. Through combining the implementation and adoption aspects of e-government, this thesis proposes a unified conceptual model which could be used as a frame of reference by government institutions that seek to implement and diffuse e-government systems in Qatar. To do so, the research draws from two well established theoretical models, Institutional Theory (for understanding implementation) and the Unified Theory of Acceptance and Use of Technology (UTAUT) model (for understanding adoption). The research adopted a multi-method approach [combining qualitative (interviews) and quantitative (survey) methods] to explore practices and experiences of implementing and adopting e-government systems in the State of Qatar

Islamic education elementary teachers’ degree of using e-learning skills in their teaching process, and its relationship with some variables, in Hail Region

This study aimed at identifying the Islamic education elementary teachers’ degree of using e-learning skills in their teaching process, and its relationship with some variables in Hail Region. And to achieve the objectives of the study; the researcher had used a questionnaire consisted of (33) statements covering two fields, and it has been applied to a sample of 90 male and female teachers during the first academic semester 2015/2016. The study results showed that the degree of possession of e-learning skills that the teachers of Islamic education have in the elementary stage in their teaching came significantly, and also showed that there are no statically significant differences due to gender and  teaching experience variables, and in the light of the study results the researcher presented a set of recommendations which will hopefully benefit the decision makers of educational policy, curriculum and teachers in schools for the universal use of e-learning in the educational system learning-processes, including the importance of mobilizing schools with capabilities that allows the use of innovative e-learning processing, and holding training courses for all teachers, through which they are updated on the newest techniques in the field of using e-learning.

A Framework to support aerospace knowledge transfer to developing countries via collaborative projects

There are economic, strategic and technological needs for establishing a national aerospace sector in many developing countries. This is to support the growing demands for aerospace related products and to encourage international collaborations. International collaboration projects can cost billions of US dollars, but provide opportunities to access and gain aerospace knowledge in terms of skills, technologies and infrastructure related to the purchased aerospace systems. While there are several options for international technology transfer, there are currently no effective approaches, specifically in aerospace knowledge transfer, for international collaboration projects between developed and developing countries. There is a need for a specific framework to guide developing countries in this task and to overcome different transfer challenges. This paper presents an aerospace knowledge transfer framework (Aero-KT) to effectively manage knowledge transfer into developing countries during international aerospace collaboration projects

Efficiency of the Settlement Influence by Settlement Patterns at the Zaatari Camp, Jordan

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Regeneration of Amman center — social acceptance of Syrian migrants in downtown Amman

Several studies discussed attitudes towards migrants; some of the issues pointed out are integration that requires interaction between migrants and the host society. Homogenous social groupings produce stronger communities. As the conflict in Syria entered its fifth year, Jordan hosted about 1.4 million registered Syrians, of whom 646,700 are informal refugees. Eighty-five percent of the refugees live outside camps in some of the poorest areas of Jordan. Consequently, new household’s typologies pressured the supply side. Such non-camp refugees’ migration patterns and housing market conditions formed ethnic homogeneous enclaves in different locations in Amman. Accordingly, non-camp refugees occupied and rented the upper floors of mixed used commercial buildings in downtown Amman. The present study investigated social acceptance of Syrian migrants residing in upper floors of commercial mixed used buildings located in the city center of Amman. The primary purpose of this research is to study how social acceptance of Syrian migrants is influenced by social gating. The hypothesis of the present study states that social acceptance of Syrian migrants in downtown Amman is influenced by sense of merchants’ sense of social gating. The significance of the study stems from that the development of downtown Amman with such rich social context can be informative and useful for strategic planners, local governments, NGO’s, social workers, and psychologists. This paper offers such an opportunity to reflect on an unfolding crisis that is of major social concern with changing urban demographics. The study was conducted using a quantitative and qualitative research strategy; an embedded research design was used. The quantitative method was conducted using a survey with downtown merchants, in addition to supportive qualitative methods of face-to-face interviews. The study was conducted in the central part of Amman, known locally as Wast Al-balad, which is considered the old commercial area that dates back to the second quarter of the twentieth century. Some of these secondary residential units became spaces (enclaves) for migrants that formed ethnic low-income enclaves. In the last five years, low-income Syrian migrants started to rent these units in Amman’s urban center. Outcomes indicated that social cohesion is the strongest motivator for acceptance of outsiders by the local merchants to reside in the upper floors of the commercial buildings of Downtown Amman area

Modeling Uncertainty in Seismic Stability and Earthquake Induced Displacement of Earth Slopes Under Short Term Conditions

Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes and embankments under earthquake loading using both the safety factor and the displacement criteria of slope failure. These models are formulated and incorporated within a computer program (PTDDSSA). The probabilistic models evaluate the probability of failure under seismic loading considering the different sources of uncertainties involved in the problem. A sensitivity analysis was conducted on the different parameters involved in the developed models by applying those models to a well-known landslides (Congress Street) under different levels of seismic hazard. The hypocentral distance and earthquake magnitude were found to have major influence on the earthquake induced displacement, probability of failure (i.e. probability of allowable displacement exceedance), and dynamic 2-D and 3-D safety factors

Comparison Between Finite Element Predictions and Results from Dynamic Centrifuge Tests on Tilting Gravity Wall Retaining Dry Sand

An analytical model is developed to analyze the seismic response of gravity walls retaining and founded on dry sand, with special emphasis on tilting behavior. A well verified two-dimensional finite element code is used for this purpose. The analytical model is verified comparing predictions to results from three dynamic centrifuge tests, with satisfactory agreement. Moreover, sensitivity analyses are carried out for one of the centrifuge test conditions to understand how the results would change if the boundary conditions and rotational stiffness of the wall were changed