Simple design rules for optimal design of dielectric temperature-compensated sapphire resonators

2003 ◽  
Vol 50 (9) ◽  
pp. 1204-1206 ◽  
Author(s):  
M.E. Tobar ◽  
D. Cros ◽  
J.G. Hartnett ◽  
P. Blondy ◽  
P. Guillon
Keyword(s):  
Optimal Design ◽  
Simple Design ◽  
Design Rules

scholarly journals Electrocharged facepiece respirator fabrics using common materials

2020 ◽  
Vol 476 (2243) ◽  
pp. 20200469
Author(s):  
M. M. Bandi
Keyword(s):  
Design Principles ◽  
Simple Design ◽  
Design Rules ◽  
Global Pandemic ◽  
Practical Design ◽  
Cotton Candy ◽  
Set Up ◽  
Filtration Properties ◽  
Plastic Containers

Face masks in general, and N95 filtering facepiece respirators (FRs) that protect against SARS-Cov-2 virion in particular, have become scarce during the ongoing COVID-19 global pandemic. This work presents practical design principles for the fabrication of electrocharged filtration layers employed in N95 FRs using commonly available materials and easily replicable methods. The input polymer is polypropylene or polystyrene, and can include discarded plastic containers of these materials, and the fabrication set-up is based on the cotton candy (CC) principle. The primary parameters underlying the CC principle are translated to simple design rules that allow anyone to construct their own fabrication system from common parts, or employ a commercial CC machine with minimal modifications. Finally, basic characterization results for structural and filtration properties of electrocharged fabrics made using the CC principle are detailed.

Design of Tree-Shaped Microchannel Networks Submitted to Simultaneous Pressure Driven and Electro-Osmotic Flows

2012 ◽  
Author(s):  
Christine Barrot ◽  
Stéphane Colin
Keyword(s):  
Optimal Design ◽  
Heat Exchangers ◽  
Analytical Study ◽  
Geometrical Configuration ◽  
Chemical Reactors ◽  
Design Rules ◽  
Electro Osmosis ◽  
Parallel Microchannels ◽  
Electro Osmotic Flow ◽  
Pressure Driven

Microchannel networks can be efficiently used for several applications. For example, they can be the main elements of micro chemical reactors or micro heat exchangers for cooling electronic chips. In such networks, the flow of liquid can be generated either by a pressure difference, by electro-osmosis or by both of them. The design of the network can be optimized in order to deliver a maximum flowrate. In this paper, an analytical study of a pressure driven and electro-osmotic flow in tree-shaped microchannel network is developed. The network is built with a series of rectangular microchannels with high aspect ratio. Each bifurcation connects a parent microchannel to a couple of twin child microchannels. The objective of this work is to determine the geometrical configuration which offers the highest flowrate. The efficiency of the tree-shaped network is compared to the efficiency of a series of parallel microchannels, for the same inlet and outlet values of electric potential and pressure and for the same network volume. Focusing on one bifurcation, the influence of the thickness of the electrical double layer is discussed. The optimal geometric dimensions, such as the ratio of the child over parent microchannel widths and the ratio of the parent over total microchannel lengths, are calculated. The influence of the number of bifurcations is also analyzed and optimal design rules are proposed.

scholarly journals A method for nanofluidic device prototyping using elastomeric collapse

2009 ◽  
Vol 106 (37) ◽  
pp. 15549-15554 ◽  
Author(s):  
Seung-min Park ◽  
Yun Suk Huh ◽  
Harold G. Craighead ◽  
David Erickson
Keyword(s):  
Applied Strain ◽  
Simple Design ◽  
Pdms Mold ◽  
Design Rules ◽  
Surface Enhanced ◽  
Elastomeric Materials ◽  
Surface Enhanced Raman ◽  
Promising Solution ◽  
Nanofluidic Device ◽  
Biomolecular Analysis

Nanofluidics represents a promising solution to problems in fields ranging from biomolecular analysis to optical property tuning. Recently a number of simple nanofluidic fabrication techniques have been introduced that exploit the deformability of elastomeric materials like polydimethylsiloxane (PDMS). These techniques are limited by the complexity of the devices that can be fabricated, which can only create straight or irregular channels normal to the direction of an applied strain. Here, we report a technique for nanofluidic fabrication based on the controlled collapse of microchannel structures. As is demonstrated, this method converts the easy to control vertical dimension of a PDMS mold to the lateral dimension of a nanochannel. We demonstrate here the creation of complex nanochannel structures as small as 60 nm and provide simple design rules for determining the conditions under which nanochannel formation will occur. The applicability of the technique to biomolecular analysis is demonstrated by showing DNA elongation in a nanochannel and a technique for optofluidic surface enhanced Raman detection of nucleic acids.

Fluctuating Lift Forces on Aerofoils Moving Through Transverse and Chordwise Gusts

1968 ◽  
Vol 90 (4) ◽  
pp. 494-500 ◽  
Author(s):  
J. H. Horlock
Keyword(s):  
Compressor Blade ◽  
Simple Design ◽  
Flow Disturbance ◽  
Design Rules ◽  
Lift Forces ◽  
Undisturbed Flow

An analysis is given for determining the lift fluctuation on an aerofoil due to a gust parallel to the undisturbed flow. By combining the new analysis with an established theory for “transverse” gusts perpendicular to the undisturbed flow, it is possible to obtain the fluctuating lift on a rotating fan or compressor blade moving through a flow disturbance. It is shown that simple design rules may be derived for fans and compressors if the fluctuating lift forces, and possibly therefore the associated noise, are to be reduced.

AN ADAPTIVE OBSERVER DESIGN FOR AUTO-SYNCHRONIZATION OF LORENZ SYSTEM

2008 ◽  
Vol 18 (08) ◽  
pp. 2415-2423 ◽  
Author(s):  
YING LIU ◽  
WALLACE TANG ◽  
LJUPCO KOCAREV
Keyword(s):  
Lyapunov Exponents ◽  
Chaotic Systems ◽  
Lorenz System ◽  
Observer Design ◽  
Adaptive Observer ◽  
Simple Design ◽  
Unknown Parameters ◽  
Dynamical Equations ◽  
Design Rules ◽  
The Past

Synchronization of chaotic systems with unknown parameters, or namely auto-synchronization, has aroused a lot of interest in the past few years. In this paper, we are interested in solving one of the critical cases in Lorenz system. Based on the past researches, it was concluded that the auto-synchronization of Lorenz system was inachievable if the unknown parameters resided in all of its three dynamical equations while only the first state was measurable. However, as demonstrated in this paper, this problem can be resolved by an adaptive observer following simple design rules. The design is justified with the conditional Lyapunov exponents, and its effectiveness is clearly illustrated in simulations.

Monotonicity Analysis in Optimum Design of Marine Risers

1982 ◽  
Vol 104 (4) ◽  
pp. 849-854 ◽  
Author(s):  
P. Papalambros ◽  
M. M. Bernitsas
Keyword(s):  
Optimal Design ◽  
Optimization Problem ◽  
Static Pressure ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Design Rules ◽  
Marine Risers ◽  
Two Dimensional Model ◽  
Polynomial Expression ◽  
Monotonicity Analysis

The optimal design of marine risers used for drilling and production of oil in offshore operations is studied. The optimization problem is formulated on a two-dimensional model for bending of circular tubular beams under tension and internal and external static pressure. A general polynomial expression describes the external hydrodynamic loads. Monotonicity analysis is used to identify active constraints, determine design rules, and reduce the size of the problem.

Optimal Design Rules Applied to the Design of High-Speed Mechanisms Under Deflection and Stress Constraints

1989 ◽  
Author(s):  
F. W. Liou ◽  
J. D. Liu
Keyword(s):  
Optimal Design ◽  
Optimality Conditions ◽  
Design Process ◽  
High Speed ◽  
Minimum Weight ◽  
Stress Constraints ◽  
Design Rules ◽  
Interpolation Technique ◽  
Second Procedure ◽  
Flexible Mechanisms

Abstract Presented in this paper are two approaches for the design of flexible mechanisms under stress and deflection constraints. Based on the optimality conditions derived in this paper, two procedures are developed to design the minimum weight of mechanisms subject to stress and deflection limitations. The first procedure is the improvement of Thornton’s design process [17], and the second procedure is based on the interpolation technique. Several design examples are also presented to demonstrate these methods.

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