ET-332 Project Presentation Slides

2020 ◽

pp. 182-194

Author(s):

Kaloshin Vadim ◽

Zhang Ke

Keyword(s):

Mechanical System ◽

System P ◽

Variational Property

This chapter describes the variational property of the slow mechanical system. The main goal is to derive some properties of the “channel” and information about the Aubrey sets. More precisely, the chapter proves Proposition 5.1. It provides a condition for the “width” of the channel to be non-zero. The chapter then discusses the limit of the set, which corresponds to the “bottom” of the channel. It drops all subscripts “s” to simplify the notations. The results proved in the chapter are mostly contained in John Mather's works. The chapter reformulates some of them for its purpose and also provides some different proofs.

Download Full-text

Deception attack monitoring in vulnerable hydroelectric generator system

Asian Journal of Control ◽

10.1002/asjc.2686 ◽

2021 ◽

Author(s):

Bilal Sari ◽

Mohamed Amine Sid

Keyword(s):

Generator System ◽

Hydroelectric Generator

Download Full-text

Efficiency Comparison of Hydro Turbines in a Micro Generator System from Free-flow Vortex

10.20944/preprints202110.0217.v1 ◽

2021 ◽

Author(s):

Piyawat Sritram ◽

Ratchaphon Suntivarakorn

Keyword(s):

Cross Flow ◽

Free Flow ◽

Generator System ◽

Hydroelectric Generator ◽

Turbine Housing ◽

Efficiency Comparison ◽

Flow Vortex ◽

Hydro Turbines

This study aimed to enhance a micro hydroelectric generator system driven by free-flow vortex and to compare efficiency of Propeller and Crossflow turbines. Series of turbines in each type were designed and tested at water-flowrate of 0.02 m3/s. The turbine housing has 1 meter in diameter and 0.5-meter height with 2 meters outlet drain at the bottom. The best efficiency extracted from Crossflow turbines with the same height (0.3 meter) but different in diameter (0.4, 0.5, 0.6, and 0.7 meter) and numbers of blade (12, 18, 24, 30, and 23) was from an 18 blades turbine at 23.01% of efficiency. The best efficiency extracted from Propeller turbines with 5 blades was from a 0.4-meter-high turbine with a diameter of 0.7 meter at 13.92% of efficiency. There were 12 Propeller turbines designed in this study. They were different in height (0.2, 0.3, and 0.4 meter) and, in each height, 0.4, 0.5, 0.6, and 0.7 of diameter was applied. The result revealed that Cross Flow turbine had more efficiency to the system than Propeller turbine (9.09%) at the water-flowrate of 0.02 m3/s

Download Full-text

Comparison of TEM and STM observations of small silver clusters on different carbon supports

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017445x ◽

1990 ◽

Vol 48 (4) ◽

pp. 264-265

Author(s):

Bernd Tesche ◽

Tobias Schilling

Keyword(s):

Vibration Isolation ◽

Pyrolytic Graphite ◽

Carbon Film ◽

Silver Clusters ◽

Carbon Supports ◽

Stacking Order ◽

System P ◽

High Resolution Tem ◽

High Degree ◽

Degree Of Order

The objective of our work is to determine:a) whether both of the imaging methods (TEM, STM) yield comparable data andb) which method is better suited for a reliable structure analysis of microclusters smaller than 1.5 nm, where a deviation of the bulk structure is expected.The silver was evaporated in a bell-jar system (p 10−5 pa) and deposited onto a 6 nm thick amorphous carbon film and a freshly cleaved highly oriented pyrolytic graphite (HOPG).The average deposited Ag thickness is 0.1 nm, controlled by a quartz crystal microbalance at a deposition rate of 0.02 nm/sec. The high resolution TEM investigations (100 kV) were executed by a hollow-cone illumination (HCI). For the STM investigations a commercial STM was used. With special vibration isolation we achieved a resolution of 0.06 nm (inserted diffraction image in Fig. 1c). The carbon film shows the remarkable reduction in noise by using HCI (Fig. 1a). The HOPG substrate (Fig. 1b), cleaved in sheets thinner than 30 nm for the TEM investigations, shows the typical arrangement of a nearly perfect stacking order and varying degrees of rotational disorder (i.e. artificial single crystals). The STM image (Fig. 1c) demonstrates the high degree of order in HOPG with atomic resolution.

Download Full-text

Study of the dynamics of ТПА 350 automatic mill working stand elements

Ferrous Metallurgy Bulletin of Scientific Technical and Economic Information ◽

10.32339/0135-5910-2020-8-830-840 ◽

2020 ◽

Vol 76 (8) ◽

pp. 830-840

Author(s):

S. R. Rakhmanov ◽

V. V. Povorotnii

Keyword(s):

Mechanical System ◽

Dynamic Model ◽

Maximum Amplitude ◽

Calculation Scheme ◽

Dynamic Loads ◽

Forced Oscillations ◽

Mass Model ◽

Automatic Mill ◽

Hollow Billet ◽

Oscillation Movement

To form a necessary geometry of a hollow billet to be rolled at a pipe rolling line, stable dynamics of the base equipment of the automatic mill working stand has a practical meaning. Among the forces, acting on its parts and elements, significant by value short-time dynamic loads are the least studied phenomena. These dynamic loads arise during transient interaction of the hollow billet, rollers, mandrel and other mill parts at the forced grip of the hollow billet. Basing of the calculation scheme and dynamic model of the mechanical system of the ТПА 350 automatic mill working stand was accomplished. A mathematical model of dynamics of the system “hollow billet (pipe) – working stand” within accepted calculation scheme and dynamic model of the mechanical system elaborated. Influence of technological load of the rolled hollow billet variation in time was accounted, as well as variation of the mechanical system mass, and rigidity of the ТПА 350 automatic mill working stand. Differential equations of oscillation movement for four-mass model of forked sub-systems of the automatic mill working stand were made up, results of their digital calculation quoted. Dynamic displacement of the stand elements in the inter-roller gap obtained, which enabled to estimate the results of amplitude and frequency characteristics of the branches of the mill rollers setting. It was defined by calculation, that the maximum amplitude of the forced oscillations of elements of the ТПА 350 automatic mill working stand within the inter-roller gap does not exceed 2 mm. It is much higher than the accepted value of adjusting parameters of the deformation center of the ТПА 350 automatic mill. A scheme of comprehensive modernization of the rollers setting in the ТПА 350 automatic mill working stand was proposed. It was shown, that increase of rigidity of rollers setting in the ТПА 350 automatic mill working stand enables to stabilize the amplitude of forced oscillations of the working stand elements within the inter-rollers gap and considerably decrease the induced nonuniform hollow billet wall thickness and increase quality of the rolled pipes at ТПА 350.

Download Full-text

Conclusion: What is Speculative Empiricism?

10.3366/edinburgh/9781474423045.003.0013 ◽

2018 ◽

Author(s):

Didier Debaise

Keyword(s):

Social Groups ◽

Speculative Philosophy ◽

System P ◽

History Of ◽

Selection Of

Process and Reality ends with a warning: ‘[t]he chief danger to philosophy is narrowness in the selection of evidence’ (PR, 337). Although this danger of narrowness might emerge from the ‘idiosyncrasies and timidities of particular authors, of particular social groups, of particular schools of thought, of particular epochs in the history of civilization’ (PR, 337), we should not be mistaken: it occurs within philosophy, in its activity, its method. And the fact that this issue arises at the end of Process and Reality reveals the ambition that has accompanied its composition: Whitehead has resisted this danger through the form and ambition of his speculative construction. The temptation of a narrowness in selection attempts to expel speculative philosophy at the same time as it haunts each part of its system.

Download Full-text