Relationship of gain and phase in the transfer function of swirling flames

2020 ◽  
Author(s):  
Guoqing Wang ◽  
Jianyi Zheng ◽  
Lei Li ◽  
Xunchen Liu ◽  
Fei Qi
Keyword(s):  
Transfer Function ◽  
Swirling Flames ◽  
Relationship Of

scholarly journals GEODYNAMICS

GEODYNAMICS ◽  
2011 ◽  
Vol 2(11)2011 (2(11)) ◽  
pp. 155-157
Author(s):  
B. Ladanivskyy ◽  
◽  
Keyword(s):  
Transfer Function ◽  
Field Source ◽  
One Dimensional ◽  
Conductivity Model ◽  
The Earth ◽  
Mantle Conductivity ◽  
The One ◽  
Relationship Of ◽  
The Relationship ◽  
Source Structure

The regional magneto-variational sounding method (aka Z/H method) was used for estimation of the Earth's mantle conductivity model at the Panagurishte (PAG) observatory region. A magneto-variational transfer function is calculated on the base of the relationship of vertical to horizontal geomagnetic field spectra components recorded on the Earth surface and priori assumptions about a field source structure. Inversions of the transfer function allow to obtain the one dimensional conductivity model.

Influence of the Swirler Design on the Flame Transfer Function of Premixed Flames

2005 ◽  
Author(s):  
C. Hirsch ◽  
D. Fanaca ◽  
P. Reddy ◽  
W. Polifke ◽  
T. Sattelmayer
Keyword(s):  
Transfer Function ◽  
Transfer Functions ◽  
Premixed Flames ◽  
Swirl Number ◽  
Burner Exit ◽  
Novel Approach ◽  
Swirling Flames ◽  
Simplified Analysis ◽  
Vorticity Transport ◽  
Good Agreement

A novel approach to the description of flame transfer functions of premixed swirling flames is presented based on a simplified analysis of the vorticity transport equation. With this model it is possible to reproduce transfer function amplitude in excess of unity observed for swirling flames as well as to explain the differences seen in flame transfer functions for different swirler types. Measurements of flame transfer functions were performed on perfectly premixed flames generated by an axial and a radial swirler with an annular exit. Flames were adjusted as to achieve respective dynamic similarity. The comparison of the flame transfer functions shows the influence of the swirler type. Good agreement with the model validates the theoretical approach and allows to attribute the specific differences seen between the two swirler types with the generation of a swirl number modulation induced by the convective time delay between radial swirler and burner exit. The model also allows to explain the change of flame transfer function amplitude with pre-heating observed in previous publications.

scholarly journals Multivariable Control of Solar Battery Power by Extremum Seeking: Starting from Linear Analysis

Machines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 64 ◽  
Author(s):  
I.M. Kirpichnikova ◽  
A.Yu. Sologubov
Keyword(s):  
Transfer Function ◽  
Sparse Matrix ◽  
Angular Position ◽  
Open Loop ◽  
Solar Panel ◽  
Maximum Power ◽  
Extremum Seeking ◽  
Analytical Relationship ◽  
Solar Panels ◽  
Relationship Of

In this study, we tried to combine maximum power point trackers (MPPT) and «Extremum Seeking» in a single multi-parameter extremum seekeng system for orienting solar panels and draw attention to the problem of a deeper study of nonlinear adaptive control using appropriate methods for their analysis. MPPT controller becomes one of the extremum seeking loops, and as a result, the maximum power is achieved not only by searching for the optimal voltage value, but also due to the optimal angular position of the solar panel in Euclidean space, because the photocurrent depends on the angle of inclination of the Sun’s rays to the surface. The task of tuning extremum seeking loops becomes more analytically difficult, which is associated with nonlinear and multiply connected properties. This requires starting the solution from a simpler “linear” level. We applied the approach associated with the passage of modulating oscillations with a given frequency and amplitude through an open-loop system. This approach, which is generalized in this work at least for extremum seeking of the solar panels power, should be used for approximate calculations if there are no strict requirements for convergence and energy loss for the search. Research design is as follows: parametric identification of the current-voltage and volt-watt curves; obtaining the transfer function by the semi-automated sparse matrix method; reducing the order of the transfer function of coordinate electric drives by introducing a scaling factor. To the most important theoretical result, we attribute the property of the generalized amplitude of the solar panel power oscillations with multi-parameter control to be a combination of input modulating oscillations superimposed on the signals of the control integrators. Having revealed the relationship of their properties, it becomes possible to eliminate non-linearity from the system and operate only with the analytical relationship of the input modulating oscillations and the generalized oscillation of the controlled parameter. We attribute the prediction of the effect to one of the most interesting physical results, in which, for the same amplitude of modulating oscillations, the amplitudes of the photocurrent oscillations and the power of the solar panel at different angular positions will be generally different.

Bioenergetic approach to transfer function of human skeletal muscle

1994 ◽  
Vol 77 (4) ◽  
pp. 1784-1789 ◽  
Author(s):  
T. Binzoni ◽  
P. Cerretelli
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Transfer Function ◽  
Human Skeletal Muscle ◽  
Constant Load ◽  
Aerobic Activity ◽  
Relationship Of ◽  
Kinetics Of ◽  
Constant Load Exercise

A mathematical model analogous to Chance's “transfer function” was derived on the basis of the energy consumption principle, which is suitable to describe the energetics of human skeletal muscle during aerobic activity. The implications and the characteristics of this model are that 1) the half time of phosphocreatine (PCr) hydrolysis at the onset of a mechanical constant-load exercise is independent of the imposed charge, 2) the changes of O2 consumption in the muscle at steady state when changing workload are linearly related to PCr concentration, 3) the kinetics of the intracellular oxygen consumption during a rest-to-work transient are influenced by anaerobic glycolysis, 4) it may explain the PCr-time relationship of different muscles types (e.g., skeletal, heart, trained vs. untrained), 5) it allows one to interpret correctly the significance of the oxygen consumption kinetics in the rest-to-work transient at the lung level, and 6) it is conceived for in vivo applications.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

Radiation Damage of Support Films

1981 ◽  
Vol 39 ◽  
pp. 28-29
Author(s):  
H.A. Cohen ◽  
W. Chiu
Keyword(s):  
Transfer Function ◽  
Low Temperatures ◽  
Carbon Support ◽  
Contrast Transfer Function ◽  
Electron Dose ◽  
Imaging Parameters ◽  
Negative Stain ◽  
Phase Corrections ◽  
Two Parameters ◽  
Medium Dose

The goal of imaging the finest detail possible in biological specimens leads to contradictory requirements for the choice of an electron dose. The dose should be as low as possible to minimize object damage, yet as high as possible to optimize image statistics. For specimens that are protected by low temperatures or for which the low resolution associated with negative stain is acceptable, the first condition may be partially relaxed, allowing the use of (for example) 6 to 10 e/Å2. However, this medium dose is marginal for obtaining the contrast transfer function (CTF) of the microscope, which is necessary to allow phase corrections to the image. We have explored two parameters that affect the CTF under medium dose conditions.Figure 1 displays the CTF for carbon (C, row 1) and triafol plus carbon (T+C, row 2). For any column, the images to which the CTF correspond were from a carbon covered hole (C) and the adjacent triafol plus carbon support film (T+C), both recorded on the same micrograph; therefore the imaging parameters of defocus, illumination angle, and electron statistics were identical.

Possible applications of fraunhofer holography in high resolution electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 222-223 ◽  
Author(s):  
N. Bonnet ◽  
M. Troyon ◽  
P. Gallion
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Transfer Function ◽  
Radiation Damage ◽  
High Resolution Electron Microscopy ◽  
Far Field ◽  
Field Region ◽  
Crystalline Materials ◽  
Resolution Electron ◽  
The Ideal

Two main problems in high resolution electron microscopy are first, the existence of gaps in the transfer function, and then the difficulty to find complex amplitude of the diffracted wawe from registered intensity. The solution of this second problem is in most cases only intended by the realization of several micrographs in different conditions (defocusing distance, illuminating angle, complementary objective apertures…) which can lead to severe problems of contamination or radiation damage for certain specimens.Fraunhofer holography can in principle solve both problems stated above (1,2). The microscope objective is strongly defocused (far-field region) so that the two diffracted beams do not interfere. The ideal transfer function after reconstruction is then unity and the twin image do not overlap on the reconstructed one.We show some applications of the method and results of preliminary tests.Possible application to the study of cavitiesSmall voids (or gas-filled bubbles) created by irradiation in crystalline materials can be observed near the Scherzer focus, but it is then difficult to extract other informations than the approximated size.

Sign in / Sign up

Export Citation Format

Share Document