Fundamentals of design and performance matching of scrubbers and ship diesel installations

Отмечается, что вступление в силу в 2015году норм на содержание серы в морских топливах 0,1 % для особых районов контроля и в 2020 г. 0,5% за их пределами привело к росту интереса судовладельцев к системам абсорбционной очистке отработавших газов с использованием скруббера. Соответственно в короткий период времени различными производителями были предложены судовладельцам различные модели систем с рассматриваемой технологией в основе. Это требует анализа существующего опыта проектирования и выполнения дополнительных исследований как по устранению влияния систем очистки на экономичность судовой дизельной установкой, так и по повышению их эффективности. Рассмотрение этих задач является целью настоящего исследования. В его основу положен анализ как собственных исследований авторов, так и результаты расчетных и экспериментальных исследований, выполненных с их участием. В отличии от ранее выполненных работ в настоящей статье рассматриваются практические вопросы проектирования и согласования элементов систем очистки с характеристиками дизельных установок. Рассмотрены взаимосвязи элементов абсорбционных систем очистки с системами судна и их двигателей. It is observed that the entry into force in 2015. Marine fuels new sulfur standards of 0.1% for special control areas and in 2020, 0.5% outside of them have increased interests of ship owners in the systems of absorption cleaning of exhaust gases by running the scrubber. Accordingly, in a short period, various manufacturers offered to the ship-owners wide range of systems configurations based on the technology under consideration. This requires an analysis of the existing design experience and the implementation of technical studies, both to eliminate the effect of cleaning systems on the efficiency of a ship diesel installation and to increase their efficiency. Consideration of these tasks is the purpose of this research. Its fundamentals on the authors' own research analysis and on the results of computational and experimental studies carried out with their participation. In contrast to the previously performed work, this article discusses the practical issues of the design and coordination of scrubber system components with the characteristics of diesel installations. The interaction of absorption systems elements with the ship's systems and internal combustion engines is considered.

Racial Ingroup Bias and Efficiency Consideration Influence Distributive Decisions: A Dynamic Analysis of Time Domain and Time Frequency

Although previous studies have demonstrated that identity had effect on justice norms and behavioral decisions, the neural mechanism of that effect remains unclear. In this study, the subjects made their distributive decisions on the trade-off between equity and efficiency among Chinese and foreign children and their scalp potentials were recorded. Behavioral results showed that efficiency consideration played an important part in the distribution task. Meanwhile, participants gave preferential treatment to same-race children. Relative to the distribution within ingroup children, the distribution involving outgroup children induced higher N170 amplitude. The distribution involving outgroup children also elicited weakened P300 amplitude and enhanced delta response than the distribution within ingroup children when subjects are facing the conflict between equality and efficiency. In other words, ingroup bias affected the neural process of the trade-off between equality and efficiency. The combination of time-domain and time-frequency analyses provided spatiotemporal and spectral results for a better understanding of racial ingroup favoritism on distributive justice.

Information Technology in Mining Services Applications

An overview of information technology (IT) in underground mining services applications is discussed against the backdrop of the vital challenges that this technology has to prevail for successful implementation in these hazardous environments. The application of IT is broken down into a number of key areas, for example, information dissemination, safety, remote operations, mine mechanization, fleet management, environmental impact, exploration of coal and minerals, process improvement and efficiency. Consideration is also given to future prospects of IT in mining industry.

Effects of Defects on Nanoporous Graphene and MoS2

Nanoporous 2D materials such as grapheme and MoS2 promises better filtrations in water channels. However certain parameters that affects these materials for effective deployment need to be studied. In this paper, molecular dynamics (MD) simulation was performed to study the effects of defects that could increase the prospect of tuning the efficiency of the materials in the transportation, catalysis and mechanical reaction efficiency. Consideration of the interfaces between them could lead to improved functionalities of the materials. This paper systematically compares MoS2 and graphene membranes to highlight specific features and benefits. the Young’s modulus of the pristine monolayer MoS2 was calculated to be 447GPa while that of the defective MoS2 was found to be in the range of (314–374) GPa. The Young’s Modulus for Graphene was 783.2 GPa. The relative variation of the Young’s modulus on MoS2 is in the range (13–35) % while that of graphene is (13–21) %. From the results obtained, the maximum pressure that the MoS2 can withstand depends not just on the spacing and size of the nanopores, but also on the area of the defects in the membrane. These findings could help build and proliferate tunable filtration nanodevices and other applications.

Radiation forces constrain the FRB mechanism

ABSTRACT We provide constraints on fast radio burst (FRB) models by careful considerations of radiation forces associated with these powerful transients. We find that the induced Compton scatterings of the coherent radiation by electrons/positrons accelerate particles to very large Lorentz factors (LFs) in and around the source of this radiation. This severely restricts those models for FRBs that invoke relativistic shocks and maser-type instabilities at distances less than about 1013 cm of the neutron star. Radiation travelling upstream, in these models, forces particles to move away from the shock with an LF larger than the LF of the shock front. This suspends the photon generation process after it has been operating for less than ∼0.1 ms (observer frame duration). We show that masers operating in shocks at distances larger than 1013 cm cannot simultaneously account for the burst duration of 1 ms or more and the observed ∼GHz frequencies of FRBs without requiring an excessive energy budget (>1046 erg); the energy is not calculated by imposing any efficiency consideration, or other details, for the maser mechanism, but is entirely the result of ensuring that particle acceleration by induced Compton forces upstream of the shock front does not choke off the maser process. For the source to operate more or less continuously for a few ms, it should be embedded in a strong magnetic field – cyclotron frequency ≫ wave frequency – so that radiation forces do not disperse the plasma and shut off the engine.

Developing Fluid and Organic Curricula

Literature has argued for the importance of developing complex problem-solving and active learning capabilities among the graduates in response to the challenges posed by the Fourth Industrial Revolution. Literature has also argued for the need to promote interdisciplinary and personalised learning to nurture such future-ready graduates. To effectively fulfil and sustain this expectation, higher education curriculum must be designed to become more fluid and organic, promoting more personalized and interdisciplinary learning. This chapter outlines a curriculum framework as well as key principles and lessons learned in developing a fluid and organic curriculum through broad-based and flexible programme options. The chapter also highlights the importance of efficiency consideration to ensure scalability across a university. It is believed that such fluid and organic curricula caters to the changing demands of the industry as well as diverse learner career aspirations, interests, and the capability of learners.