Proportional-integral-plus control applications of state-dependent parameter models

This paper considers proportional-integral-plus (PIP) control of non-linear systems defined by state-dependent parameter models, with particular emphasis on three practical demonstrators: a microclimate test chamber, a 1/5th-scale laboratory representation of an intelligent excavator, and a full-scale (commercial) vibrolance system used for ground improvement on a construction site. In each case, the system is represented using a quasi-linear state-dependent parameter (SDP) model structure, in which the parameters are functionally dependent on other variables in the system. The approach yields novel SDP-PIP control algorithms with improved performance and robustness in comparison with conventional linear PIP control. In particular, the new approach better handles the large disturbances and other non-linearities typical in the application areas considered

EFFECT OF OILFIELD SULPHATE SCALES ON PRODUCTIVITY INDEX

The precipitation and deposition of scale pose serious injectivity and productivity problems. Several models have been developed for predicting oilfield scales formation and their effect on deliverability of the reservoir to aid in planning appropriate injection water programme. In this study an analytical model has been developed for predicting productivity index of reservoir with incidence of scale deposition in the vicinity of the well bore

Incorporating Community Cultural Wealth in a Community-Based Organization

This project examined how Hack the Hood, a Bay Area non-profit organization, successfully works with low-income youth of color in an outside of school context using technological skills to empower them. Critical Race Theory, community cultural wealth, and the many studies on academic success provided a model through which to examine the efficacy and cultural relevance of Hack the Hood programming using interviews and data already gathered on the organization. Based on the analysis of Hack the Hood and the promising findings related to how their work advance several of the tenets of the community cultural wealth model, this project developed a series of workshop ideas to offer educators and community organizers in other settings with a source of inspiration on how to work with low-income youth of color in culturally relevant ways that acknowledge the vast wealth and skills they already have. This project aims to build on the limited research on how programs that work with low-income youth of color can resist culturally deficit narratives and empower youth to succeed

MODELING OF WAX DEPOSITION DURING OIL PRODUCTION USING A TWO-PHASE FLASH CALCULATION

Wax deposition is a serious problem in the Petroleum Industry that results in the plugging of flow strings, formation damage, loss of hydrocarbons, increased production cost. The existing models used jn the oil industry for predicting wax phase equilibrium parameters over-estimate the amount of wax that is formed in terms of the wax weight fraction and the number of moles of solid. The Coutinho correlation is the latest of these models and is used to calculate the melting temperature and the enthalpy of fusion of the crude oil components. It did not consider the effect of branching of carbon atoms in the hydrocarbon structure/compound. But branching of carbon atoms in the hydrocarbon compounds affects its melting point. In this work, the correlation for calculating the melting temperature in crude oil developed by Coutinho has been modified to take into account the effect of branching of carbon-carbon chains in isoparaffins and the model has been used to calculate a new set of equilibrium parameter. The modified regular solution theory was used to calculate the activity coefficient ratio that was used as an input to the new model. Wax phase equilibrium flash calculations were carried out with the new set of equilibrium parameters. The wax mixture was then characterized using the weight fraction of component in the solid phase and weight fraction of component in the solid phase in the mixture. In order to check the reliability of the model, the data presented by Hanquan was used as input into the models developed by Won, Chung, Countinho and the new one. The new model predicted a more conservative value for the number of moles of solid formed, weight fraction of component in the solid phase and weight fraction of component in the solid phase in the mixture for C1s-C4o.This is an improvement over the existing models which overestimate the values of the parameters

Methodology, theoretical framework and scholarly significance: An overview of International best practices in legal research

Communicating the results of painstaking legal research efforts is arguably as important as conducting the research itself. Established international publication outlets apply diverse submission guidelines for prospective authors. One common currency, however, is that getting a research paper from conception to publication, as a journal article, book chapter, or forum paper, requires an author to demonstrate a potential contribution to knowledge in the field. This requires a systematic research approach that unpacks contemporary issues in an analytical manner; a clear and concise presentation of ideas with focus on effectiveness; adoption of tested theoretical frameworks to underpin new ideas; and a careful proofreading of manuscript to ensure that a prospective publication meets the expected standards of good quality contribution to theory, practice or policy. This article discusses the indispensable standards and important guidelines that authors should weigh before writing papers for publication, most especially for internationally recognized journals. The authors draw on their experiences as Editorial Board members of national and international journals to unpack key theoretical, methodological and practical issues that legal researchers should consider when developing legal research papers.Keywords: Legal Research, Methodology, Theory, Pedagogy, Legal Training, Scholarshi

A New Model for Predicting Elemental Sulphur Deposition in a Sour Gas Reservoir

This research work is concerned with developing a more accurate correlation for the prediction of elemental sulphur deposition in a sour gas reservoir by exploring the relationship between compaction and elemental sulphur deposition over time and also incorporating porosity damage caused by reservoir compaction into the previous models in order to obtain a more robust representation of what actually occurs in the reservoir. The models considered indicates that the established new model gives the most accurate, reliable and practical result in predicting sulphur deposition which suggests that the rate of sulphur precipitation is seemed to have been underestimated by previous models. This may have not been unconnected with the fact that the new model based on non-Darcy flow, incorporated the porosity reduction caused by reservoir compaction which has been hitherto neglected by previous works. Therefore, reservoir compaction is a common phenomenon, which should be considered in sulphur deposition prediction since it leads to a faster rate of sulphur deposition

Elemental Sulphur Induced Formation Damage Management in Gas Reservoir

Sulphur compounds are considered as the most hazardous non-hydrocarbons in reservoir fluids, because of their corrosive nature, deleterious effects of petroleum products and tendency to plug porous medium which may impair formation productivity. Precipitation and deposition of elemental sulphur within reservoirs, near well bore region may significantly reduce the inflow performance of sour-gas wells and thus affect economic feasibility negatively. Studies have sought that almost all deep sour reservoirs precipitate elemental sulphur either occurring as a result of decomposition of H2S to give elemental sulphur or occurring as indigenous usually referred to as native sulphur as a dissolved species. Uncontrollable elemental sulphur induced formation damage has been one of the profit hurting syndromes that occurs in deep water sour gas reservoir. Meanwhile many correlations have been formulated thermodynamically to predict the occurrences of elemental sulphur but little information related to effect of its saturation on gas production and its corresponding formation damage. This paper presents an improved model for predicting elemental sulphur saturation and corresponding formation damage around the well bore. Results show that the minimum pore spaces blockage time was over-estimated by previous formulatio