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Element failure probability of soil slope under consideration of random groundwater level
No full textYesThe instability of soil slopes is directly related to both the shear parameters of the soil material and the groundwater, which usually causes some uncertainty. In this study, a novel method, the element failure probability method (EFP), is proposed to analyse the failure of soil slopes. Based on the upper bound theory, finite element discretization, and the stochastic programming theory, an upper bound stochastic programming model is established by simultaneously considering the randomness of shear parameters and groundwater level to analyse the reliability of slopes. The model is then solved by using the Monte-Carlo method based on the random shear parameters and groundwater levels. Finally, a formula is derived for the element failure probability (EFP) based on the safety factors and velocity fields of the upper bound method. The probability of a slope failure can be calculated by using the safety factor, and the distribution of failure regions in space can be determined by using the location information of the element. The proposed method is validated by using a classic example. This study has theoretical value for further research attempting to advance the application of plastic limit analysis to analyse slope reliability.National Natural Science Foundation of China (grant no. 51564026), the Research Foundation of Kunming University of Science and Technology (grant no. KKSY201904006) and the Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province (grant no. ZJRM-2018-Z-02)
Analytical model for the suspended sediment concentration in the ice-covered alluvial channels
No full textYesIce cover formed on an alluvial channel can significantly alter the flow characteristics, such as the vertical distributions of streamwise velocity and shear stress, and hence the water and sediment transport process. The vertical profile of the suspended sediment concentration in the ice-covered alluvial channels with steady uniform flows is investigated in this study. To calculate the suspended sediment concentration, we are based on the Schmidt O'Brien equation and deduce an analytical model that employs an existing eddy viscosity model and a modified formula of the sediment fall velocity considering the common effects of the upper and lower boundaries. The proposed analytical model is then validated by using available experimental data reported in the literature. The predicted accuracy of the proposed model is evaluated through error statistics by comparing to previous modeled results. The relative concentration profiles of the suspended sediment are subsequently simulated by applying the validated analytical model with different characteristic parameters. Results show that the relative concentration decreases with the increase of both the ice cover roughness and the sediment fall velocity. The uniformity of the relative concentration distribution is closely related to the value of the proportionality parameter σ, revealing the physical mechanism that the more prominent the turbulent diffusion effect is, the more uniform the relative concentration profile is.National Natural Science Foundation of China (grant 604 numbers 52020105006 and 11872285), Open Funding of State Key Laboratory of Water Resources and Hydropower Engineering Science (WRHES), Wuhan University (Project number 2018HLG01)
Study of wave-induced seabed response around twin pipelines in sandy seabed through laboratory experiments and numerical simulations
No full textYesWave-seabed-pipelines interaction is of critical importance in the design of submarine pipelines. Previous studies mainly focus on investigating the characteristics of flow fields and hydrodynamics around a single pipeline. In this study, laboratory experiments and numerical simulations have been performed to examine the effect of burial depth and space between the centers of twin pipelines on the wave-seabed-twin pipelines interaction subject to waves. In the mathematical model, the Volume-Averaged Reynolds-Averaged Navier-Stokes (VARANS) equations are used to describe the wave motion in the fluid domain, while the seabed domain is described by using the Biot's poro-elastic theory. Numerical models are validated using these experimental measurements and available relevant experimental data. Experimental and numerical results indicate that the burial depth and relative position of twin pipelines can significantly affect the wave-averaged flow velocity field and the pore-water pressure distribution as well as effective stress
Visualising the Crucible of Shetland’s Broch Building. The role of digital documentation and legacy data in supporting the research, active conservation and presentation of Shetland’s heritage
No full textArts and Humanities Research Council, through a Collaborative Doctoral Partnership studentshipThe full text will be available at the end of the embargo perio
Organisational Agility of Social Enterprises: A Phenomenological Study of Microfinance Institutions in Ethiopia
Get PDFThis doctoral study examines whether MFIs in Ethiopia have developed the managerial readiness to face emerging threats and seize the opportunities within the context of unpredictable changes and turbulences. The interpretative phenomenological approach (IPA) has been used to collect, shape, and interpret the lived experiences, intuitions, and insights of 10 CEOs of MFIs. The data were interpreted using the double hermeneutic and analysed through the lenses of the theory of organisational agility and the Cynefin framework to make decisions. The premise of this study is that MFIs without agile organisational capability may fail to prepare and respond to changes in the external environment. The study results show multiple impediments that restrict MFIs from being adaptive towards achieving double bottom lines, i.e., the creation of social and financial value. MFIs in Ethiopia suffer from “pain points” such as inflation, illiquidity, and turbulences. The challenges include: the weak governance practice of nominal shareholders, outdated decision-making processes causing delays, staff turnover reducing enterprising capacity, and MFIs lacking sufficient digital and technological infrastructure. The study found most MFIs are incapable of responding quickly and innovatively to seize opportunities or to overcome adversities. The conclusion is that MFIs in Ethiopia have inadequate agile organisational capability to make strategic choices and execute operational processes during multiple and complex changes. The findings of the research are important, and pertinent for a better understanding of the organisational agility of social enterprises. The study has provided five recommendations to enhance policies and practical actions to build the agile organisational capabilities of social enterprises
Towards design and implementation of Industry 4.0 for food manufacturing
Get PDFYesToday’s factories are considered as smart ecosystems with humans, machines and devices interacting with each other for efficient manufacturing of products. Industry 4.0 is a suite of enabler technologies for such smart ecosystems that allow transformation of industrial processes. When implemented, Industry 4.0 technologies have a huge impact on efficiency, productivity and profitability of businesses. The adoption and implementation of Industry 4.0, however, require to overcome a number of practical challenges, in most cases, due to the lack of modernisation and automation in place with traditional manufacturers. This paper presents a first of its kind case study for moving a traditional food manufacturer, still using the machinery more than one hundred years old, a common occurrence for small- and medium-sized businesses, to adopt the Industry 4.0 technologies. The paper reports the challenges we have encountered during the transformation process and in the development stage. The paper also presents a smart production control system that we have developed by utilising AI, machine learning, Internet of things, big data analytics, cyber-physical systems and cloud computing technologies. The system provides novel data collection, information extraction and intelligent monitoring services, enabling improved efficiency and consistency as well as reduced operational cost. The platform has been developed in real-world settings offered by an Innovate UK-funded project and has been integrated into the company’s existing production facilities. In this way, the company has not been required to replace old machinery outright, but rather adapted the existing machinery to an entirely new way of operating. The proposed approach and the lessons outlined can benefit similar food manufacturing industries and other SME industries.Innovate UK—Knowledge Transfer Partnerships (KTP010551
The perceived and objective availability of green and blue spaces and quality of life in people with dementia: results from the IDEAL programme
No full textYesThe aim of this study was to investigate the associations between quality of life and both perceived and objective availability of local green and blue spaces in people with dementia, including potential variation across rural/urban settings and those with/without opportunities to go outdoors.
This study was based on 1540 community-dwelling people with dementia in the Improving the experience of Dementia and Enhancing Active Life (IDEAL) programme. Quality of life was measured by the Quality of Life in Alzheimer’s Disease (QoL-AD) scale. A list of 12 types of green and blue spaces was used to measure perceived availability while objective availability was estimated using geographic information system data. Regression modelling was employed to investigate the associations of quality of life with perceived and objective availability of green and blue spaces, adjusting for individual factors and deprivation level. Interaction terms with rural/urban areas or opportunities to go outdoors were fitted to test whether the associations differed across these subgroups.
Higher QoL-AD scores were associated with higher perceived availability of local green and blue spaces (0.82; 95%CI: 0.06, 1.58) but not objective availability. The positive association between perceived availability and quality of life was stronger for urban (1.50; 95%CI: 0.52, 2.48) than rural residents but did not differ between participants with and without opportunities to go outdoors
Only perceived availability was related to quality of life in people with dementia. Future research may investigate how people with dementia utilise green and blue spaces and improve dementia-friendliness of these spaces
Investigation about profitability improvement for synthesis of benzyl acetate in different types of batch distillation columns
Get PDFYesIn this work, for the first time, the synthesis of benzyl acetate via the esterification of acetic acid and benzyl alcohol is investigated in the reactive distillation system using a middle vessel (MVD), inverted (IBD), and conventional batch reactive distillation columns. The measurement of the performance of these column schemes is determined in terms of profitability through minimization of the batch time for a defined separation task. The control variables (reboil ratio for MVD, IBD columns) and (reflux ratio in case of CBD column) are considered as piecewise constants over batch time. The optimization results obviously indicate that the CBD system is a more attractive process in terms of batch time reduction, and maximum achievable yearly profit as compared to the MVD, and IBD operations
Eccentric compression behaviour of concrete columns reinforced with steel-FRP composite bars
Get PDFYesEccentric compression behaviour of reinforced concrete (RC) columns reinforced by steel-FRP composite bars
(SFCBs) was investigated through experimental work and theoretical analyses. The tension and compression test results
show that SFCBs demonstrate a stable post-yield stiffness. The mechanical properties of the composite reinforcement
have a significant influence on eccentric compression behaviour of the reinforced concrete columns, in terms of failure
mode, crack width, deformation and bearing capacity. Formulae were also developed to discriminate failure mode and to
determine moment magnification factor, bearing capacity and crack width of the columns studied, with the theoretical
predictions being in a good agreement with the experimental results. In addition, parametric studies were conducted to
evaluate the effects of mechanical properties of reinforcement, reinforcement ratio, eccentricity, slenderness ratio, types of
reinforcement and concrete on the eccentric compression behaviour of RC columns. The results show that the
compressive performance is significantly improved by using the high performance concrete, i.e. reactive powder concrete
(RPC) and engineered cementious composites (ECC).National Natural Science Foundation of China (51678514), the Natural Science Foundation of Jiangsu Province, China (BK20201436), the China Postdoctoral Science Foundation (2018M642335), the Science and Technology Project of Jiangsu Construction System (2018ZD047), the Deputy General Manager Science and Technology Project of Jiangsu Province (FZ20200869), the Cooperative Education Project of Ministry of Education, China (201901273053), the Blue Project Youth Academic Leader of Colleges and Universities in Jiangsu Province (2020), the Six Talent Peaks Project of Jiangsu Province (JZ-038, 2016), the Yangzhou University Top Talents Support Project and the Jiangsu Government Scholarship for Overseas Studies
The Dynamics of Border Disputes in State Making: The Fragile Borderlands in the Northern Region between Nigeria and Benin Republic in West Africa
Get PDFAfrican borders were arbitrarily drawn by the European powers. The post-independence African leaders agreed to maintain the inherited arbitrary partitions as discarding them would open doors for more crisis between African states. However, sixty years after independence, border disputes continued to persist. This study investigates why border disputes persist between Nigeria and Benin Republic despite available regional and bilateral mechanisms, the area in contention has no strategic value or economic significance, and no overlapping power struggle between the states and the border communities. Empirical data were collected using the case study method. The key finding of the study revealed that the domestic politics in the challenge state, Benin Republic played an important role in the initialization and persistence of the border dispute. The initialization of the border dispute was linked to tenure elongation in the challenger state while the persistence of the dispute was due to the challenger state’s resilience and dependence on policies and decisions of their previous Government and the nonchalant attitude of the target state, Nigeria towards its borders and borderland communities.Petroleum Technology Development Fund (PTDF) scholarshi