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Natural gas hydrate (NGH) has been regarded as one of the most important resources due to NGH's large amounts of reserve. However, NGH development still faces many technical challenges, such as low production rate and reservoir instability resulting from NGH decomposition. Therefore, developing a fully coupled THMC model for simulating the hydrate decomposition and studying its mechanical behavior is very important and necessary. The purpose of this article is to develop and solve a multi-phase, strong nonlinearity and large-scale fully coupled thermal-hydro-mechanical–chemical (THMC) model for simulating the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and rock deformation during NGH decomposition.

In this paper, a multi-phase, strong nonlinearity and large-scale fully coupled THMC model is developed for simulating the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and rock deformation during NGH dissociation. The fully coupled THMC model is solved by using a fully implicit finite element method, in which the gas pressure, water pressure, temperature and displacement are taken as basic unknown variables. The proposed model is validated against with the experimental data, showing high accuracy and reliability.

A multi-phase, strong nonlinearity and large-scale fully coupled THMC model is developed for simulating the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and rock deformation during NGH decomposition. The proposed model is validated against with the experimental data, showing high accuracy and reliability.

Some assumptions are made to make the model tractable, including (1) the composition gas of hydrate is pure methane; (2) the gas-liquid multi-phase flow in the pore obeys Darcy's law; (3) hydrate occurs on the surface of soil particles, both of them form the composite consolidation material; (4) the small-strain assumption is applied to composite solid materials, which are treated as skeletons and cannot be moved; (5) momentum change caused by phase change is not considered.

NGH has been regarded as one of the most important resources due to its large amounts of reserve. However, NGH development still faces many technical challenges, such as low production rate and reservoir instability resulting from NGH decomposition. Most of the existing studies decouple the process with solid deformation and seepage behavior, but the accuracy of the numerical results will be sacrificed to certain extent. Therefore, it is very important and necessary to develop a fully coupled THMC model for simulating the hydrate decomposition and studying its mechanical behavior.

NGH, widely distributed in shallow seabed or permanent frozen region, has the characteristics of high energy density and high combustion efficiency (Yan et al., 2020). A total of around 7.5 × 1,018 m³ has been proved to exist around the world and 1 m³ of NGH can release about 160–180 m³ of natural gas (Kvenvolden and Lorenson) under normal conditions. Safely and sustainably extracting NGH commercially can effectively relieve global energy pressure and contribute to achieving carbon reduction goals.

The novelty of the present work lies in mainly two aspects. First, a fully coupled THMC model is developed for studying the multi-physics processes involving solid-liquid-gas flow, heat transfer, NGH phase change and solid deformation during NGH dissociation. Second, the numerical solution is obtained by using a fully implicit finite element method (FEM) and is validated against experimental data.

The purpose of this paper is to study the multi-phase flow behaviors in solid fluidization exploitation of natural gas hydrate (NGH) and its effect on the engineering safety.

In this paper, a multi-phase flow model considering the endothermic decomposition of hydrate is established and finite difference method is used to solve the mathematical model. The model is validated by reproducing the field test data of a well in Shenhu Sea area. Besides, optimization of design parameters is presented to ensure engineering safety during the solid fluidization exploitation of NGH in South China Sea.

To ensure the engineering safety during solid fluidization exploitation of marine NGH, taking the test well as an example, a drilling flow rate range of 40–50 L/s, drilling fluid density range of 1.2–1.23 g/cm3 and rate of penetration (ROP) range of 10–20 m/h should be recommended. Besides, pre-cooled drilling fluid is also helpful for inhibiting hydrate decomposition.

Systematic research on the effect of multiphase flow behaviors on the engineering safety is scare, especially for the solid fluidization exploitation of NGH in South China Sea. With the growing demand for energy, it is of great significance to ensure the engineering safety before the large-scale extraction of commercial gas from hydrate deposits. The result of this study can provide profound theoretical bases and valuable technical guidance for the commercial solid fluidization exploitation of NGH in South China Sea.

The purpose of this paper is to investigate the impact of layout configurations in a hospital on the implementation of lean management initiatives, to include different units of care. The research concentrated on the impact, the physical distance between dependent units could have on staff perception, use of staff time, time spent in the system by patients, and performance.

The research examined the relationship between clinical units allocated within Northampton General Hospital and their internal providers. In addition, an adapted version of the SERVPERF questionnaire was used to measure the quality perception of staff.

The transit distances from each clinical unit to their internal providers have: a negative relationship with the staff quality provision of care; a positive relationship with the time the patient spends in the system; and no discernable direct correlation with performance.

These findings will help hospital managers to understand the impact of the layout of a hospital on the implementation of service improvement activities, and will assist them in planning improved relocation of clinical units. This facilitates future service improvements whilst optimising the use of available and constrained resources within the present hospital facilities.

The ideas and results presented in this study are original and valuable to the study of hospital layouts, services improvements and the implementation of lean operation initiatives and quality improvement programmes in hospitals. The study also successfully tested the application of SERVPERF in a hospital setting.

The purpose of this paper is to demonstrate the applicability of swarm and evolutionary techniques for regularized machine learning. Generally, by defining a proper penalty function, regularization laws are embedded into the structure of common least square solutions to increase the numerical stability, sparsity, accuracy and robustness of regression weights. Several regularization techniques have been proposed so far which have their own advantages and disadvantages. Several efforts have been made to find fast and accurate deterministic solvers to handle those regularization techniques. However, the proposed numerical and deterministic approaches need certain knowledge of mathematical programming, and also do not guarantee the global optimality of the obtained solution. In this research, the authors propose the use of constraint swarm and evolutionary techniques to cope with demanding requirements of regularized extreme learning machine (ELM).

To implement the required tools for comparative numerical study, three steps are taken. The considered algorithms contain both classical and swarm and evolutionary approaches. For the classical regularization techniques, Lasso regularization, Tikhonov regularization, cascade Lasso-Tikhonov regularization, and elastic net are considered. For swarm and evolutionary-based regularization, an efficient constraint handling technique known as self-adaptive penalty function constraint handling is considered, and its algorithmic structure is modified so that it can efficiently perform the regularized learning. Several well-known metaheuristics are considered to check the generalization capability of the proposed scheme. To test the efficacy of the proposed constraint evolutionary-based regularization technique, a wide range of regression problems are used. Besides, the proposed framework is applied to a real-life identification problem, i.e. identifying the dominant factors affecting the hydrocarbon emissions of an automotive engine, for further assurance on the performance of the proposed scheme.

Through extensive numerical study, it is observed that the proposed scheme can be easily used for regularized machine learning. It is indicated that by defining a proper objective function and considering an appropriate penalty function, near global optimum values of regressors can be easily obtained. The results attest the high potentials of swarm and evolutionary techniques for fast, accurate and robust regularized machine learning.

The originality of the research paper lies behind the use of a novel constraint metaheuristic computing scheme which can be used for effective regularized optimally pruned extreme learning machine (OP-ELM). The self-adaption of the proposed method alleviates the user from the knowledge of the underlying system, and also increases the degree of the automation of OP-ELM. Besides, by using different types of metaheuristics, it is demonstrated that the proposed methodology is a general flexible scheme, and can be combined with different types of swarm and evolutionary-based optimization techniques to form a regularized machine learning approach.

This paper reports on a study of companies using homeworkers, carried out to gather information regarding the employment status of homeworkers and the health and safety provision afforded to homeworkers. It considers traditional industrial homeworking and home teleworking. For those having employee status, health and safety provision was not necessarily commensurate with legal requirements. In the case of self‐employed status, the health and safety provision was deemed adequate if the employment status was one of genuine self‐employment. However, as the analysis of the data suggests if the status was one of employment, then the health and safety provision is not adequate.

Describes how, in order to disprove the misconception that although TQM is a good idea it would not work in their company/sector, the University of Northumbria has set up a Best Practices Club that enables companies to exchange ideas, successes and failures on the subject, for the benefit of others. Asserts that the biggest benefit of the club is that it helps companies to realise that their problems are not unique ‐ other people have experienced them and found solutions. Concludes that no one company has a monopoly on the best ideas and that the club has shown that best practice is applicable to all industries.

This paper addresses access to formal health care among Cape Verdean immigrants in the Netherlands, and their transnational health‐seeking process in other European countries. Three barriers hindering Cape Verdeans' access to care have been identified: lack of information about the health services available, problems in the relationship with health providers and difficulties in dealing with the conditionality of help. These problems are deeply intertwined, and relate to two sets of factors. At the macro‐level these include the organisational and structural characteristics of the Dutch health care system. At the micro‐level, the problems concern the mismatch between users' and providers' expectations of health care provision.Despite the barriers encountered, Cape Verdeans strive to benefit from good health. The informants in this study employ two sorts of strategy to access good health care. On the one hand, they try to adapt their help‐seeking behaviour to the model prevalent in the Netherlands. On the other, they resort to transnational health care use in other European countries, including Portugal and France. These strategies prove Cape Verdeans' resilience in finding the care that is most appropriate to their needs.

In 1980, 8 per cent of women in the UK were classified as obese (body mass index over 30). By 1998, the prevalence of obesity had increased to 21 per cent and there is no sign that this upward trend is moderating. Many women retrospectively attribute the onset of their obesity to pregnancy, yet research in this area has yielded conflicting evidence. Unlike the USA, the UK does not have clinical guidelines for gestational weight gain. Health professionals such as GPs, midwives and obstetricians have a responsibility to monitor normal pregnancy, yet typically in the UK, women are weighed only once i.e. at the antenatal booking appointment, which is primarily undertaken for the interpretation of screening tests. This paper will review recent evidence relating gestational weight gain and maternal outcomes such as the burden of postpartum obesity and the risk of caesarean section. In addition, some practical advice is given for heath professionals to use when monitoring the weight gain of pregnant women in their care.

A bilingual Welsh‐English full text database is planned for Inspection Reports of Her Majesty's Inspectors of Schools for Wales. Special requirements for free text retrieval in the Welsh language are identified, and practical solutions are proposed for problems arising from the use of standard text database products, some of which may also apply to other lesser‐used languages.