13 research outputs found

    A study of LNG processes to determine the effect of end flash systems on efficiency

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    This paper describes the simulation, exergy analysis and com- parison of two commonly applied liquefaction of technologies natural gas, namely: propane precooled mixed refrigerant process (C3MR) and dual mixed refrigerant process (DMR) alongside two modifications of each em- ploying end flash systems. The C3MR and DMR process schemes were simulated using the commercial software to mathematically model chemi- cal processes. These schemes were then analysed using energy and exergy calculations to determine their performances. The exergy efficiency for the C3MR processes without end flash system, with simple end flash system and extended end flash system were evaluated as 29%, 31%, and 33%, respec- tively, while the exergy efficiency for the DMR processes without end flash system, with simple end flash system, and extended end flash system were evaluated as 26%, 25.5%, and 30%, respectively. The results achieved show that the extended end flash system versions of the schemes are most effi- cient. Furthermore, the exergy analysis depicted that the major equipment that must be enhanced in order to improve the cycle exergy efficiencies are the compressors, heat exchangers, and coolers

    Transition to Turbulence of a Laminar Flow Accelerated to a Statistically Steady Turbulent Flow

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    This current study investigates the turbulence response in a flow accelerated from laminar to a statistically steady turbulent flow utilising Particle Image Velocimetry (PIV) and Constant Temperature Anemometry (CTA). The dimensions of the rectangular flow facility are 8 m in length, 0.35 m in width, and 0.05 m in height. The flow is increased via the pneumatic control valve from a laminar to a statistically steady turbulent flow, and the laminar-turbulent transition is examined. As the flow accelerates to turbulent from laminar, the friction coefficient increases quickly and approaches its maximum value within a short period. As a result, a boundary layer forms extremely near to the wall, increasing the velocity gradient and viscous force. The friction coefficient and viscous force decrease with increasing boundary layer thickness, and transition occurs as a result of instability of the boundary layer. The friction coefficient is used to specify the beginning and end of the transition. The transition starts when the friction coefficient reaches its minimal value. It increases again, and its maximum value marks the end of the transition to turbulence. The study shows that three stages lead to turbulence near the wall when the flow is accelerated from laminar to turbulent. These phases are similar to the transient turbulent flow reported. The reaction of mean velocity as laminar flow is accelerated to turbulent flow is investigated. The mean velocity behaves like a "plug flow" when the flow accelerates from laminar to turbulent, meaning that everywhere in the flow zone, except for the position extremely near the wall, the flow behaves like a solid body. The changes in the channel flow that accelerates from a laminar to a turbulent condition are presented, together with the turbulence statistics, wall shear stress, bulk velocity, and friction coefficient. Like the boundary layer bypass transition and transient turbulent flows, the transition to turbulence follows a similar process

    Relevance of Chemically Functionalized Nano-Fillers and Modified Nanocomposite in Energy Systems

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    Reliable energy systems and advances in nanotechnology together will play key role in channeling future cutting edge inventions and developments in all spheres. In this review article, the pertinence of functionalizing nanofillers and modifying nanocomposites for improved performance in various energy applications such as energy conversion, energy efficiency, energy storage, alternative energy and energy saving are expounded. This article also presents structures and unique properties of commonly used nanofillers; advances, improvement potentials and characterization of nanocomposites used in energy systems. Theoretical and experimental literature reviewed revealed that nanofillers engender improved properties in polymeric matrices. Functionalization is applicable to all types of nanofillers in use today, a number of functionalized nanofillers are already commercially available; and more extensive research is needed to achieve optimal improved results with the use of nanofillers and nanocomposites in various fields of applications

    Dance in the Yoriba Family Rites of Birth, Marriage and Death

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    A study of LNG processes to determine the effect of end flash systems on efficiency

    No full text
    This paper describes the simulation, exergy analysis and comparison of two commonly applied liquefaction of technologies natural gas, namely: propane precooled mixed refrigerant process (C3MR) and dual mixed refrigerant process (DMR) alongside two modifications of each employing end flash systems. The C3MR and DMR process schemes were simulated using the commercial software to mathematically model chemical processes. These schemes were then analysed using energy and exergy calculations to determine their performances. The exergy efficiency for the C3MR processes without end flash system, with simple end flash system and extended end flash system were evaluated as 29%, 31%, and 33%, respectively, while the exergy efficiency for the DMR processes without end flash system, with simple end flash system, and extended end flash system were evaluated as 26%, 25.5%, and 30%, respectively. The results achieved show that the extended end flash system versions of the schemes are most efficient. Furthermore, the exergy analysis depicted that the major equipment that must be enhanced in order to improve the cycle exergy efficiencies are the compressors, heat exchangers, and coolers

    Cellular interactions in tumor microenvironment during breast cancer progression: new frontiers and implications for novel therapeutics

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    The breast cancer tumor microenvironment (TME) is dynamic, with various immune and non-immune cells interacting to regulate tumor progression and anti-tumor immunity. It is now evident that the cells within the TME significantly contribute to breast cancer progression and resistance to various conventional and newly developed anti-tumor therapies. Both immune and non-immune cells in the TME play critical roles in tumor onset, uncontrolled proliferation, metastasis, immune evasion, and resistance to anti-tumor therapies. Consequently, molecular and cellular components of breast TME have emerged as promising therapeutic targets for developing novel treatments. The breast TME primarily comprises cancer cells, stromal cells, vasculature, and infiltrating immune cells. Currently, numerous clinical trials targeting specific TME components of breast cancer are underway. However, the complexity of the TME and its impact on the evasion of anti-tumor immunity necessitate further research to develop novel and improved breast cancer therapies. The multifaceted nature of breast TME cells arises from their phenotypic and functional plasticity, which endows them with both pro and anti-tumor roles during tumor progression. In this review, we discuss current understanding and recent advances in the pro and anti-tumoral functions of TME cells and their implications for developing safe and effective therapies to control breast cancer progress
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