Upside-Down Molding Approach for Geometrical Parameter-Tunable Photonic Perovskite Nanostructures

2021 ◽  
Author(s):  
Lebin Nie ◽  
Wai Kit Ng ◽  
ZhiFu Liang ◽  
Xingang Ren ◽  
Tingbin Yang ◽  
...  
Keyword(s):  
Geometrical Parameter

Recent Patents on Nanoporous Filtration Membranes with Complex Pores

2020 ◽  
Vol 14 (2) ◽  
pp. 229-233
Author(s):  
Yongbin Zhang
Keyword(s):  
Geometrical Parameter ◽  
Filtration Membranes ◽  
Analytical Results ◽  
Parameter Values ◽  
Mechanical Strengths ◽  
Better Than

Background:: The challenges to nanoporous filtration membranes are small fluxes and low membrane mechanical strengths. Objective:: To introduce newly invented nanoporous filtration membranes with complex pores, improved fluxes and mechanical strengths as registered in patents. Methods:: The analytical results are presented for the addressed membranes. Results:: The geometrical parameter values of the addressed membranes can be optimized for the highest fluxes. Conclusion:: The overall performances of nanoporous filtration membranes with complex cylindrical or/and conical pores can be significantly better than that of the conventional nanoporous filtration membranes with single cylindrical or conical pores.

Efficiency limits of fans

2019 ◽  
Vol 234 (5) ◽  
pp. 739-748
Author(s):  
Konrad Bamberger ◽  
Thomas Carolus
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Geometrical Parameter ◽  
The Self ◽  
Complex Geometries ◽  
Relevant Parameter ◽  
Optimization Scheme ◽  
Loss Models ◽  
Definition Of

The purpose of this work is to identify upper efficiency limits of industrial fans such as axial rotor-only fans, axial with guide vanes, centrifugal rotor-only and centrifugal with volute. The efficiency limit is always a function of the class, the design point within the class and the definition of efficiency (total-to-static and total-to-total). The characteristic Reynolds number is another relevant parameter. First, based on analytical and empirical loss models, a theoretical efficiency limit is estimated. A set of idealizing assumptions in the loss models yields efficiencies which are assumed to be an insuperable limit but may be unrealistically high. Second, more realistic efficiency limits are estimated using a computational fluid dynamics-based optimization scheme, seeking for the best designs and hence the maximum achievable efficiencies in all classes. Given the self-imposed constraints in the geometrical parameter space considered, the thus-obtained practical efficiency limits can only be exceeded by admitting more complex geometries of the fans.

scholarly journals APPROACH TO RATIONAL CALCULATION OF SUPERELEVATION IN DUAL GAUGE TRACK

Transport ◽  
2018 ◽  
Vol 33 (3) ◽  
pp. 699-706 ◽  
Author(s):  
Inesa Gailienė ◽  
Martynas Gedaminskas ◽  
Alfredas Laurinavičius
Keyword(s):  
Present Article ◽  
Geometrical Parameter ◽  
Advantages And Disadvantages ◽  
Rail Wear ◽  
Calculation Methodology ◽  
Rational Calculation ◽  
The Subject

One of the technical possibilities to solve a gauge crossing is to install a dual gauge. This solution has several advantages and disadvantages discussed in this paper. Lack of experience of maintenance and lack of standards for the design of dual track are among the most important disadvantages. The wheel and rail interface on track curves is more difficult than in straight sections. Therefore, the subject of the present article is a geometrical parameter of dual gauge track, i.e., the rail superelevation, which has an impact on the wheel–rail interaction at curves and influences the value of uncompensated acceleration, occurring when a train passes a curve, and, consequently, the intensity of rail wear. The objective of the present article is to analyse the features of dual gauge track and the superelevation calculation methodology considered, to present the approach to rational calculation of superelevation for dual gauge track of Šeštokai–Mockava (Lithuania–Poland) using several calculation versions as well as to make recommendations for the calculation of superelevation.

Analytical Solutions to the Problem of Transient Heat Transfer in Living Tissue

1978 ◽  
Vol 100 (4) ◽  
pp. 202-210 ◽  
Author(s):  
A. Shitzer ◽  
J. C. Chato
Keyword(s):  
Heat Transfer ◽  
Blood Flow ◽  
Temperature Profile ◽  
Analytical Solutions ◽  
Biological Tissue ◽  
Geometrical Parameter ◽  
Convective Transport ◽  
Transient Heat Transfer ◽  
Living Tissue ◽  
Cylindrical Coordinates

An analytical model of transient heat transfer in living biological tissue is considered. The model includes storage, generation, conduction, and convective transport of heat in the tissue. Solutions for rectangular and cylindrical coordinates are presented and discussed. Transient times for reaching the “locally fully developed” temperature profile were found to be of the order of 5–25 min. These transients are dominated by a geometrical parameter and, to a lesser extent, by a parameter representing the ratio of heat supplied by blood flow to heat conducted in the tissue.

Effects of the Interaction Point of Multi-Passage Swirlers on the Swirling Flow Field

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Foad Vashahi ◽  
Jeekeun Lee
Keyword(s):  
Geometrical Parameter ◽  
Swirling Flow ◽  
Energy Levels ◽  
Fuel Mixture ◽  
Mean Flow ◽  
Interaction Point ◽  
Stagnation Points ◽  
Image Velocimetry ◽  
The Mean ◽  
Proper Orthogonal

An experimental study is conducted to understand the mean and instantaneous behavior of the swirling flow issued from a triple swirler influenced by a single critical geometrical parameter, termed as the passage length. The investigated geometrical parameter defines the interaction point of the inner axial swirlers with the outer radial swirler, which consequently defines the primary air–fuel mixture characteristics and the resultant combustion state. Experiments were performed under cold flow conditions, and planar particle image velocimetry was employed to measure the velocity field. The mean flow pattern exhibited significant differences in terms of the swirl-jet width and angle and altered the number of stagnation points on the swirler axis. When the passage length was reduced to half, two stagnation points appeared on the swirler axis due to an initially developed smaller recirculation zone at the swirler mouth. Also, the turbulent activity at the vicinity of the swirler increased with as the passage length reduced. Investigations on the relocation of the second stagnation point on the axis through an arbitrary window revealed identical standard deviation in x and y directions. The energetic coherent structures extracted from the proper orthogonal decomposition also identified major differences in terms of the spatial distribution of the modes and their corresponding energy levels. The experimental results indicated that if the passage length is altered, the number of stagnation points on the swirler axis increases, and a breakdown of both the bubble and cone vortex may appear at the same time as different energy levels.

Passive Control of Unstable Characteristics of a High Specific Speed Diagonal-Flow Fan by an Annular Wing

1990 ◽  
Author(s):  
Kenji Kaneko ◽  
Toshiaki Setoguchi ◽  
Masahiro Inoue
Keyword(s):  
Flow Rate ◽  
Geometrical Parameter ◽  
Energy Input ◽  
Passive Control ◽  
Internal Flow ◽  
Flow Region ◽  
Low Flow ◽  
Performance Tests ◽  
Flow Measurements ◽  
Specific Speed

A passive control of an unstable characteristics of a high specific speed diagonal-flow fan has been proposed. It is possible to eliminate the unstable characteristics of pressure-flow rate curve in a low flow region without deterioration of performance at design point. The control action is done naturally (passively) without any energy input. The inlet nozzle of an ordinary diagonal-flow fan was replaced by an annular wing with Göttingen 625 airfoil section. The mechanism of the passive control and the optimum geometrical parameter are discussed on the basis of the performance tests and internal flow measurements.

Interpolation of molecular wave functions with a variable geometrical parameter

1983 ◽  
Vol 79 (12) ◽  
pp. 6425-6426
Author(s):  
Raffaele Montagnani ◽  
Pierluigi Riani ◽  
Oriano Salvetti
Keyword(s):  
Geometrical Parameter ◽  
Wave Functions
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