A Method for Liquid Level Detection Under Complicated Boundary Conditions

2006 ◽  
Vol 128 (4) ◽  
pp. 535-539 ◽  
Author(s):  
Frank May ◽  
Jürg Dual
Keyword(s):  
Simple Model ◽  
Boundary Conditions ◽  
Liquid Surface ◽  
Experimental Results ◽  
Liquid Level ◽  
Longitudinal Vibrations ◽  
Resonant Vibrations ◽  
Vibrating System ◽  
As If ◽  
Liquid Level Detection

In this paper a method of liquid level detection by mechanical resonant vibrations is presented which is based on longitudinal vibrations of a steel capillary and is able to detect a liquid surface even if covered with foam, as well as if the fluid container is shut by a cap. The behavior of the vibrating system is calculated by a simple model and compared with experimental results.

The Combined Effect of Wages and Firm Profit on Employee Effort

2005 ◽  
Vol 80 (1) ◽  
pp. 167-188 ◽  
Author(s):  
R. Lynn Hannan
Keyword(s):  
Gift Exchange ◽  
Experimental Results ◽  
Combined Effect ◽  
Financial Reward ◽  
Ex Post ◽  
Employee Effort ◽  
Profit Maximizing ◽  
Firm Profit ◽  
As If

This study investigates whether paying higher wages motivates employees to provide higher effort and whether firm profit moderates this relation. Consistent with gift exchange (Akerlof 1982) and reciprocity (Rabin 1993) models, my experimental results show that workers provided more effort when they were paid higher wages even though there was no ex post financial reward for doing so. Moreover, firm profit influenced the relation between wages and effort. Workers provided higher effort when firm profit decreased compared to when it increased. This suggests that the degree of reciprocity is affected by firm profit. However, workers' responded asymmetrically to firm profit, in that they behaved as if they expected to share in firm profit increases but not decreases. Although firms were fairly adept at predicting the profit-maximizing wage strategy, they apparently did not anticipate workers' reluctance to share in firm profit decreases.

Surface Aeration Threshold in Agitated Vessels

1996 ◽  
Vol 61 (5) ◽  
pp. 681-690
Author(s):  
Kamil Wichterle ◽  
Tomáš Svěrák
Keyword(s):  
Simple Model ◽  
Liquid Surface ◽  
Power Input ◽  
Power Number ◽  
Region Analysis ◽  
Surface Aeration ◽  
Liquid Dispersion ◽  
Mixing Vessels ◽  
Number Curve

Violent agitation of liquids in mixing vessels may result in the regime of surface aeration being attained when the bubbles formed at the liquid surface enter the impeller region. Analysis of data on surface aeration for different liquids in a set of geometrically similar agitated vessels is presented. Data on the just aerated state as observed visually in transparent liquids, and data for the efficient aeration as determined from the break on the power number curve are considered. A simple model is developed for correlation of the data which enables the threshold of aeration to be predicted from the value of the recirculation number Nc = Nd (ρ/σg)1/4. The possibility of interpreting various literature data for the aeration threshold and for the power input with use of Nc is demonstrated. Similar modelling rules hold also for the correlation of beginning of the efficient liquid-liquid dispersion.

Spectral Methods

2018 ◽  
Author(s):  
S. G. Rajeev
Keyword(s):  
Simple Model ◽  
Differential Equations ◽  
Boundary Conditions ◽  
Linear Algebra ◽  
Spectral Methods ◽  
Differential Operators ◽  
Higher Dimensions ◽  
Standard Linear ◽  
Sommerfeld Equation ◽  
Spectral Discretization

Thenumerical solution of ordinary differential equations (ODEs)with boundary conditions is studied here. Functions are approximated by polynomials in a Chebychev basis. Sections then cover spectral discretization, sampling, interpolation, differentiation, integration, and the basic ODE. Following Trefethen et al., differential operators are approximated as rectangular matrices. Boundary conditions add additional rows that turn them into square matrices. These can then be diagonalized using standard linear algebra methods. After studying various simple model problems, this method is applied to the Orr–Sommerfeld equation, deriving results originally due to Orszag. The difficulties of pushing spectral methods to higher dimensions are outlined.

The Hardware Design and Implementation of Liquid Level Detection System for Lead-Acid Battery

2013 ◽  
Vol 860-863 ◽  
pp. 2850-2854 ◽  
Author(s):  
Ya Jun Bi ◽  
Hong Fei Li
Keyword(s):  
Detection System ◽  
Low Cost ◽  
Liquid Level ◽  
Lead Acid Battery ◽  
Infrared Transmission ◽  
Wireless Data ◽  
Linear Ccd ◽  
Infrared Technology ◽  
Liquid Level Detection ◽  
Lead Acid

The hardware structure of a liquid level detection system for lead-acid battery was briefly introduced. The system adopts AT89C51 MCU as host module, combined with display storage, extended storage and the watch dog technology. The slave module adopts AT89C2051 MCU, which driver the linear CCD to realize non-contact measurement in acidic and corrosive conditions. The infrared transmission module uses RS-232 serial-to-infrared technology to realize wireless data delivery. The damage due to sensor corrosion could be avoided in this system. Compared with other similar equipments, this system has the advantages of simple structure, small volume, low cost, high measure precision and convenient maintenance.

scholarly journals Modelling of ‘sub-atomic’ contrast resulting from back-bonding on Si(111)-7×7

2016 ◽  
Vol 7 ◽  
pp. 937-945 ◽  
Author(s):  
Adam Sweetman ◽  
Samuel P Jarvis ◽  
Mohammad A Rashid
Keyword(s):  
Simple Model ◽  
Experimental Results ◽  
Striking Similarity ◽  
Orbital Structure ◽  
Dangling Bond ◽  
Lennard Jones ◽  
Detailed Explanation ◽  
Afm Imaging ◽  
Back Bonding ◽  
Molecular Contrast

It has recently been shown that ‘sub-atomic’ contrast can be observed during NC-AFM imaging of the Si(111)-7×7 substrate with a passivated tip, resulting in triangular shaped atoms [Sweetman et al. Nano Lett. 2014, 14, 2265]. The symmetry of the features, and the well-established nature of the dangling bond structure of the silicon adatom means that in this instance the contrast cannot arise from the orbital structure of the atoms, and it was suggested by simple symmetry arguments that the contrast could only arise from the backbonding symmetry of the surface adatoms. However, no modelling of the system has been performed in order to understand the precise origin of the contrast. In this paper we provide a detailed explanation for ‘sub-atomic’ contrast observed on Si(111)-7×7 using a simple model based on Lennard-Jones potentials, coupled with a flexible tip, as proposed by Hapala et al. [Phys. Rev. B 2014, 90, 085421] in the context of interpreting sub-molecular contrast. Our results show a striking similarity to experimental results, and demonstrate how ‘sub-atomic’ contrast can arise from a flexible tip exploring an asymmetric potential created due to the positioning of the surrounding surface atoms.

scholarly journals Small Caliber Bulletproof Test of Warships’ Hulls

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3848
Author(s):  
Radosław Kiciński ◽  
Andrzej Kubit
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Method Simulation ◽  
Material Model ◽  
Experimental Results ◽  
Material Constants ◽  
Steel Core ◽  
Calculation Results ◽  
Simulation Results

The article presents the characteristics of 1.3964 steel and the results of firing a 7.62 mm projectile with a steel core. A simplified Johnson–Cook material model for steel and projectile was used. Then, a FEM (finite element method) simulation was prepared to calibrate the material constants and boundary conditions necessary to be used in simulations of the entire hull model. It was checked how projectile modeling affects the FEM calculation results. After obtaining the simulation results consistent with the experimental results, using the model of a modern minehunter, the resistance of the ship’s hull to penetration by a small-caliber projectile was tested.

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