Fourier transform of the general expression for the magnetic anomaly due to a long horizontal cylinder

Geophysics ◽  
1980 ◽  
Vol 45 (6) ◽  
pp. 1091-1093 ◽  
Author(s):  
K. S. R. Murthy ◽  
D. C. Mishra
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Magnetic Anomaly ◽  
Cross Section ◽  
General Expression ◽  
Horizontal Cylinder ◽  
The Body ◽  
The Cross ◽  
Three Components

The general expression for the magnetic anomaly due to a long horizontal cylinder (Gay, 1965) applicable to all three components, i.e., ΔT, ΔZ, and ΔH, is transformed to obtain its characteristics in the frequency domain. The transformed expression clearly demonstrates that its decay is primarily controlled by the depth of the model, while its value at ο = 0 depends upon the nature of magnetization and the cross‐section of the body. It is possible, therefore, to derive the parameters of the causative model directly from the computed transform of the measured anomaly.

scholarly journals STUDIES ON CILIA

1965 ◽  
Vol 26 (3) ◽  
pp. 805-834 ◽  
Author(s):  
Peter Satir
Keyword(s):  
Cross Section ◽  
Length Change ◽  
The Body ◽  
Cell Of Origin ◽  
Ciliary Movement ◽  
The Matrix ◽  
Morphological Specialization ◽  
Dense Band ◽  
The Cross ◽  
Different Order

Termination of peripheral filaments of the axoneme of gill cilia of fresh-water mussels (Elliptio or Anodonta) occurs in characteristic fashion: (a) subfiber b of certain doublets ends leaving a single simplified tubular unit; (b) the wall of the unit becomes thick and may even obliterate the interior; and (c) the filament drops out of the 9 + 2 pattern. The order in which doublets begin simplifying is also characteristic. This may be determined by numbering the filaments, those with the bridge being 5–6, with the direction of numbering determined by the apparent enantiomorphic configuration (I to IV) of the cross-section. Shorter filaments can be identified in simplifying tips with mixed double and single peripheral units. In this material, laterofrontal cirri show a morphological specialization in the region where individual cilia simplify. The cilia studied run frontally from the body of the cirrus and point in the direction of effective stroke. The longest filaments (Nos. 3, 4, 5, 6, 7) appear as the doublets at the bottom of the cross-section, nearest the surface of the cell of origin. Above them, and above the central pair, a dark band (a section of a dense rod) runs through the matrix. The remaining filaments are the single units. Effective-pointing frontal and lateral ciliary tips end in a fashion similar to laterofrontal tips, although no dense band is present. For all effective-pointing tips studied, the order in which the peripheral filaments end appears to be Nos. (9, 1), 8, 2, 7, 6, 3, 4, 5. However, recovery-pointing lateral tips show a different order: Nos. 7, 6, 8, 5, 9, 4, 1 (3, 2), although the longer filaments are still at the bottom of the cross-section. In simple models of ciliary movement involving contraction of the peripheral filaments, filaments at the top of the cross-section should be longer, if any are. Such models are not supported by the evidence here. These results can be interpreted as supporting sliding-filament models of movement where no length change of peripheral filaments occurs.

scholarly journals GENERAL CASE OF REINFORCED CONCRETE ROD ELEMENTS CALCULATION USING THE DIAGRAM METHOD

2021 ◽  
Vol 93 (1) ◽  
pp. 26-37
Author(s):  
O.V. RADAYKIN ◽  
◽  
L.S. SABITOV ◽  
L.SH. AKHTYAMOVA ◽  
T.P. ARAKCHEEV ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Longitudinal Force ◽  
Internal Force ◽  
The Other ◽  
Bending Moments ◽  
Diagram Method ◽  
The Cross ◽  
Three Components

In SP 63.13330 the general calculation case for the diagram method is oblique off-center compression, which takes into account only three components of internal force factors in the cross section: the longitudinal force-Nz – and two bending moments relative to the corresponding axes – Mx and My. The other three components-the QX and Qy transfer forces and the MZ torque – are left out of consideration. In addition, for this case, the search in the available literature, including the founders of the diagram method, for the output of calculation formulas was not successful – in all sources they are given in ready-made form without evidence. This article is intended to try to fill in these gaps. For this purpose, based on the expressions for rod displacements that are generally accepted in mechanics, in particular on the Mora integral of displacements, the resolving expressions of the diagram method are obtained in the most general form.

scholarly journals Threshold of the upper airway cross-section for hypopnea onset during sleep and its identification under waking condition

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hongyi Lin ◽  
Cunting Wang ◽  
Han Zhang ◽  
Huahui Xiong ◽  
Zheng Li ◽  
...  
Keyword(s):  
Cross Section ◽  
Airway Resistance ◽  
Upper Airway ◽  
The Body ◽  
Sigmoid Function ◽  
Fluid Accumulation ◽  
Normal Breathing ◽  
Obstructive Sleep ◽  
The Cross ◽  
Shape Changes

Abstract Background There is currently no method that can predict whether or under what condition hypopnea, even obstructive sleep apnea (OSA), will occur during sleep for individuals based on credible parameters measured under waking condition. We propose a threshold concept based on the narrowest cross-sectional area of the upper airway (CSA-UA) and aim to prove our hypothesis on the threshold of the area for hypopnea onset (TAHO), which can be used as an indicator of hypopnea onset during sleep and measured while awake. Methods We performed magnetic resonance imaging for 20 OSA patients to observe CSA-UA changes during fluid accumulation in the neck caused by elevating their legs, and identified TAHO by capturing the sudden enlargement in CSA-UA. Correlation analyses between TAHO and the body mass index (BMI), and between the reduction in CSA-UA and the increase in the neck circumference (NC) with fluid accumulation were performed. Logistic regression analysis was performed for identifying OSA patients based on the behaviors of their CSA-UA changes during leg raising. Shape changes of airway cross-section were also investigated. Results Four CSA-UA change patterns after fluid redistribution were identified. Six patients had similar CSA-UA variation behaviors observed in healthy subjects. From the other three change patterns involving 14 patients, a threshold value of CSA-UA 0.63 ± 0.21 cm2 was identified for normal breathing. Data showed a positive correlation between TAHO and BMI (r = 0.681, p = 0.0007), and a negative correlation between the reduction in CSA-UA and the increase in NC (r = − 0.513, p = 0.051) with fluid accumulation. A sigmoid function for the probability of being a OSA patient p = 1/[1 + exp. (4.836 + 3.850 t-8.4 h)] was obtained to effectively separate OSA patients from normal subjects. The upper airway narrowing occurred in anteroposterior, lateral, or both directions, suggesting different tendencies of upper airway collapse in patients. Three types of shape changes in the cross-section of the upper airway, which had different effects on airway resistance, were measured. Conclusions Our findings prove TAHO hypothesis. The threshold measured while awake for normal breathing can be used clinically as the indicator of hypopnea onset during sleep, and therefore to identify OSA patients under waking condition and design effective personalized treatments for OSA patients. Both shape and size changes in the cross-section of the upper airway affect airway resistance significantly. Shape change in the cross-section of the upper airway can provide key clinical information on the collapse patterns of the upper airway for individuals.

scholarly journals IMPLEMENTASI TRANSFORMASI FOURIER UNTUK TRANSFORMASI DOMAIN WAKTU KE DOMAIN FREKUENSI PADA LUARAN PURWARUPA ALAT PENDETEKSIAN GULA DARAH SECARA NON-INVASIF

2020 ◽  
Vol 4 (2) ◽  
pp. 234-244
Author(s):  
Umam Hidayaturrohman ◽  
Erfiani Erfiani ◽  
Farit M Afendi
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Frequency Domain ◽  
Blood Sugar ◽  
Processing Speed ◽  
Fourier Transformation ◽  
Dft Method ◽  
The Body ◽  
Non Invasive ◽  
The Time Domain

Diabetes mellitus is the result of changes in the body caused by a decrease of insulin performance which is characterized by an increase of blood sugar level. Detection of blood sugar can be done with Invasive methods or non-invasive methods. However, non-invasive methods are considered better because they can check early, faster and accurate. The prototype output is values of intensity in the time domain, thus fourier transformation is very much needed to transform into the frequency domain. In this study, Fourier transformation methods used are Discrete Fourier Transform (DFT), Fast Fourier Transform Radix-2, and Fast Fourier Transform Radix-4. Evaluation for the best method is done by comparing the processing speed of each method. The FFT Radix-4 method is more effective to perform the transformation into the frequency domain. The average processing speed with the FFT Radix-4 method reaches 2.67×105 nanoseconds, and this is much faster 5.06×106 nanoseconds than the FFT Radix-2 method and 2.40×107 nanoseconds faster than the DFT method.

Modeling of the impact of hold-down forces on the accuracy of the workpiece shape using the finite element method

2021 ◽  
pp. 9-20
Author(s):  
A.V. Zaitsev ◽  
A.N. Izosimov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
The Body ◽  
Machining Process ◽  
Mechanical Processing ◽  
The Finite Element Method ◽  
The Cross ◽  
The Impact ◽  
Element Method

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html

scholarly journals Analysis of the Spectral Characteristics of Pure Moxa Stick Burning by Hyperspectral Imaging and Fourier Transform Infrared Spectroscopy

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiao-jing Song ◽  
Shu-you Wang ◽  
Yin-long Li ◽  
Dong Zhang
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Hyperspectral Imaging ◽  
Cross Section ◽  
Spectral Range ◽  
Fourier Transform Infrared ◽  
Peak Position ◽  
Moxa Stick ◽  
The Cross

The objective of this study was to investigate the spectra characteristics (SC) at wavelengths of 400~1000 nm and 2.5~15.5 μm of pure moxa stick (MS) during its 25-minute burning process using new spectral imaging techniques. Spectral images were collected for the burning pure MS at 5, 10, 15, 20, and 25 min using hyperspectral imaging (HSI) and Fourier transform infrared spectroscopy (FTIR) for the first time. The results showed that, at wavelengths of 400~1000 nm, the spectral range of the cross section of MS burning was 750~980 nm; the peak position was 860 nm. At wavelengths of 2.5~15.5 μm, the spectral range of the cross section of MS burning was 3.0~4.0 μm; the peak position was approximately 3.5 μm. The radiation spectra of MS burning include litter red and amount of infrared (but mainly near infrared) wavelengths. The temperature, blood perfusion, and oxygen saturation increase of Shenshu (BL23) after moxibustion radiation were observed too. According to mechanism of photobiological effects and moxibustion biological effects, it was inferred that moxibustion effects should be linked with moxibustion SC. This study provided new data and means for physical properties of moxibustion research.

On Dynamics of Bar of Rectangular Cross Section

2000 ◽  
Vol 68 (4) ◽  
pp. 662-666 ◽  
Author(s):  
N. B. Rassoulova
Keyword(s):  
Fourier Transform ◽  
Closed Form ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Original Method ◽  
The Body ◽  
Closed Form Solutions ◽  
Nonstationary Waves ◽  
Parameters Inversion ◽  
Laplace And Fourier Transform

The propagation of nonstationary waves in semi-infinite elastic rectangular bars is studied. It is assumed that two opposite lateral surfaces of the body are free of forces, while the two others are subjects to cross conditions. By introducing three new potential functions, the author succeeded in getting closed-form solutions in Laplace and Fourier transform parameters. Inversion of the transform solutions, carried out by an original method of inversion, is suggested herein.

Investigation of the Cross-Section Stratifications of Icons Using Micro-Raman and Micro-Fourier Transform Infrared (FT-IR) Spectroscopy

2018 ◽  
Vol 72 (8) ◽  
pp. 1258-1271 ◽  
Author(s):  
Dimitra Lazidou ◽  
Dimitrios Lampakis ◽  
Ioannis Karapanagiotis ◽  
Costas Panayiotou
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Cross Section ◽  
Cross Sections ◽  
Lead White ◽  
Chrome Yellow ◽  
Micro Raman Spectroscopy ◽  
Ft Ir ◽  
The Cross ◽  
Ft Ir Spectroscopy

The cross-section stratifications of samples, which were removed from six icons, are studied using optical microscopy, micro-Raman spectroscopy, and micro-Fourier transform infrared (FT-IR) spectroscopy. The icons, dated from the 14th to 19th centuries, are prominent examples of Byzantine painting art and are attributed to different artistic workshops of ​​northern Greece. The following materials are identified in the cross-sections of the icon samples using micro-Raman spectroscopy: anhydrite; calcite; carbon black; chrome yellow; cinnabar; gypsum; lead white; minium; orpiment; Prussian blue; red ochre; yellow ochre; and a paint of organic origin which can be either indigo ( Indigofera tinctoria L. and others) or woad ( Isatis tinctoria L.). The same samples are investigated using micro-FT-IR which leads to the following identifications: calcite; calcium oxalates; chrome yellow; gypsum; kaolinite; lead carboxylates; lead sulfate (or quartz); lead white; oil; protein; Prussian blue; saponified oil; shellac; silica; and tree resin. The study of the cross-sections of the icon samples reveals the combinations of the aforementioned inorganic and organic materials. Although the icons span over a long period of six centuries, the same stratification comprising gypsum ground layer, paint layers prepared by modified “egg tempera” techniques (proteinaceous materials mixed with oil and resins), and varnish layer is revealed in the investigated samples. Moreover, the presence of three layers of varnishes, one at the top and other two as intermediate layers, in the cross-section analysis of a sample from Virgin and Child provide evidence of later interventions.

ESTIMATION OF THE DIRECTION OF MAGNETIZATION OF A BODY CAUSING A MAGNETIC ANOMALY USING A PSEUDO‐GRAVITY TRANSFORMATION

Geophysics ◽  
1966 ◽  
Vol 31 (4) ◽  
pp. 803-811 ◽  
Author(s):  
M. H. P. Bott ◽  
R. A. Smith ◽  
R. A. Stacey
Keyword(s):  
Magnetic Anomaly ◽  
Cross Section ◽  
Three Dimensional ◽  
The Body ◽  
Irish Sea ◽  
Simple Extension ◽  
Two Dimensional ◽  
The West ◽  
Geometrical Shapes

A two‐dimensional form of the pseudo‐gravity transformation, applicable to bodies magnetized in directions not parallel to the ambient field, is given. Assuming that a body of finite cross section is magnetized in the same direction and sense at every point, then an adaptation of this pseudo‐gravity transformation enables the direction of magnetization of the body to be estimated, within limits, from the magnetic anomaly it causes. The method has been programmed for a computer. A simple extension enables it to be applied to three‐dimensional bodies. The method is shown to be reliable by testing it against calculated magnetic profiles over geometrical shapes. It is applied to the Lambay magnetic anomaly in the west Irish Sea, showing this to be caused by a body magnetized approximately in the direction of the present earth’s field.

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