THEORETICAL INVESTIGATION OF MODAL SEISMOGRAMS FOR A LAYER OVER A HALF‐SPACE

Geophysics ◽  
1965 ◽  
Vol 30 (4) ◽  
pp. 571-596 ◽  
Author(s):  
Stanley J. Laster ◽  
Joe G. Foreman ◽  
A. Frank Linville

The use of normal modes to represent the propagation of elastic waves at large horizontal offset is well known. By addition of the relevant leaky modes, the mode theory is shown to be useful for representation of the seismograms at shorter range. A theoretical model consisting of a 2‐cm brass layer over a steel half‐space is considered. Dispersion curves and excitation functions are computed for the first four normal modes and the first three PL modes. Attenuation as a function of frequency also is computed for the PL modes. A suite of seismograms is computed for the distance range 50–70 cm, showing each mode individually and their sum (the total seismogram). It is found that, for the distances used, the individual modes do not approximate transients with a definite “arrival” time. Only their sum is required to exhibit this physical behavior. In addition, at short distances, the dispersion of a single mode is not visually obvious although the dispersion curve may be recovered by use of Fourier transform methods. Determination of the dispersion curves from the total seismogram is more difficult and requires some seperation of the modes, as they overlap in frequency and velocity. This work shows the preponderance of the leaky modes in the early part of the seismogram and indicates their importance in the later part of the seismogram for short horizontal offset.

Geophysics ◽  
2010 ◽  
Vol 75 (4) ◽  
pp. SA71-SA83 ◽  
Author(s):  
Toshiaki Yokoi

I have developed two theoretical formulas on the basis of the power partition ratios among different modes of Rayleigh waves that are newly derived theoretically from seismic interferometry (SI). These formulas, one for the spatial autocorrelation method (SPAC) and another for the centerless circular array method (CCA), are used to simulate the estimates of the dispersion curves that can be obtained from the correlation methods using microtremor in situations when the higher normal modes are present along with the fundamental mode. The formulas can provide a way to overcome the problem caused by the assumption of the dominance of the fundamental mode, which is not always true. In addition, I have conducted a numerical validation check using the synthetic microtremor waveform data that were produced by the finite-difference method. I have found that the CCA can be an alternative to the SPAC to estimate the dispersion curves. The formula for the CCA can well simulate the dispersion curves estimated by the SPAC and CCA methods, and are better than the formula based on the above-mentioned assumption. Moreover, using the data mentioned above, I have discovered that the dual-mode inversion, which considers the presence of the fundamental and first higher modes on the basis of the formula for the CCA, performs better than the conventional single-mode inversion, which rests on the above-mentioned assumption. These positive results partially support the theoretical consequence of SI, i.e., the power partition ratio, and, further, SI itself on which the theoretically derived formulas fully rely.


2007 ◽  
Vol 347 ◽  
pp. 381-386
Author(s):  
Rhys Pullin ◽  
Pete T. Theobald ◽  
Karen M. Holford ◽  
S.L. Evans

This paper reports on a method for numerically modelling acoustic emission signals in simple plate geometries using dispersion curves. It is demonstrated how, by using a known source to sensor distance, it is possible to determine the arrival of the frequencies of the individual AE modes at the sensor face. Assumptions based on sensor frequency response and the amplitude of individual modes allow for an approximation of each mode arriving at the sensor face. These modes are then summed to provide a numerical model of the expected signal. Results of the model are compared with a recorded signal and show good correlation, this is further demonstrated by comparing the wavelet transforms of the modelled and recorded signal.


1970 ◽  
Vol 6 (1) ◽  
pp. 184-193
Author(s):  
Ольга Віговська

У статті теоретично обґрунтовано феномен конструктивного самозбереження особистості як ознаки самоактуалізації, розкриття власного потенціалу і побудови перспективи розвитку особистості та емпірично виявлено ознаки психологічної детермінації домінуючого інстинкту у конструктивній самореалізації жінок з різним соціальним статусом. Зазначено, що проблема самозбереження асоціюється з особливостями прояву інстинкту самозбереження людини, але потреби вищого порядку зумовлюють соціальну природу її поведінки, яка локалізована у найвищій точці самореалізації. Теоретично обгрунтовано, що самореалізація визначає тенденцію раціональної організації життя людини та проявляється у її почутті задоволеністю життям. З’ясовано, що психологічну основу конструктивного самозбереження становлять індивідуально-типологічні характеристики людини, які відображають психофізіологічні та психосоціальні резерви самореалізації особистості. Розроблена програма емпіричного дослідження, а також комплекс використаних методів математичної обробки результатів дослідження дає змогу конкретизувати психологічний зміст детермінації домінуючого інстинкту у конструктивній самореалізації жінок вікового діапазону 35-45 років та з різним соціальним статусом. У жінок, які виховують проблемну (хвору) дитину, домінує інстинкт "егофільного типу", що виражається у їх надмірному егоцентризмі і супроводжується низькими показниками самоактуалізації, на відміну від досліджуваних жінок, які виховують здорових дітей і у яких на фоні вираженої тенденції до самоактуалізації домінує базовий інстинкт "дослідницького типу" та "лібертофільного типу". This article theoretically proves constructive phenomenon of self identity as signs of self-disclosure own potential and prospects of development of individual construction. In addition, it empirically showes signs of psychological determination of the dominant instinct in a constructive self-determination of women with different social statuses. It was noted that the issue of self-preservation is associated with the peculiarities of manifestation of self-preservation instinct of man, but it needs higher-order cause social nature of the behavior that is localized at the highest point of self-realization. It theorized that self-realization determines the trend of rational organization of human life and manifests itself in its sense of life satisfaction. It was found that the psychological basis of constructive self-preservation of the individual make individually-typological characteristics of a person that reflect physiological and psychosocial reserves of self-realization. The developed program of empirical research, as well as the methods used complex mathematical processing of results of research allows to specify the content of the psychological determination of the dominant instinct of constructive self-realization а women age range of 35-45 years and with different social status. Women who bring up the problem child dominates the instinct of self-preservation, which is reflected in their excessive self-centeredness, and is accompanied by low levels of self-actualization, as opposed to the study of women who are raising healthy children and that against the backdrop of a pronounced tendency to self-actualization, dominated by basic instinct "research type" and "independent type."


Author(s):  
O. Yu. Atkov ◽  
S. G. Gorokhova

The individual dynamics of the allostatic load index was revealed mainly due to changes in the glucose level, body mass index, which makes it applicable for assessing the short-term adaptation to the stay in the conditions of shift work


Author(s):  
Irina Mordous

The development of modern civilization attests to its decisive role in the progressive development of institutions. They identified the difference between Western civilization and the rest of the world. Confirmation of the institutional advantages of the West was its early industrialization. The genesis and formation of institutionalism in its ideological and conceptualmethodological orientation occurs as a process alternative to neoclassic in the context of world heterodoxia, which quickly spread in social science. Highlighting institutional education as a separate area of sociocultural activity is determined by the factor of differentiation of institutional theory as a whole. A feature of institutional education is its orientation toward the individual and his/her transformation into a personality. The content of institutional education is revealed through the analysis of the institution, which includes a set of established customs, traditions, ways of thinking, behavioral stereotypes of individuals and social groups. The dynamics of socio-political, economic transformations in Ukraine requires a review of the foundations of national education and determination of the prospects for its development in the 21st century in the context of institutionalism.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4842
Author(s):  
Waldemar Kamiński

Nowadays, hydrostatic levelling is a widely used method for the vertical displacements’ determinations of objects such as bridges, viaducts, wharfs, tunnels, high buildings, historical buildings, special engineering objects (e.g., synchrotron), sports and entertainment halls. The measurements’ sensors implemented in the hydrostatic levelling systems (HLSs) consist of the reference sensor (RS) and sensors located on the controlled points (CPs). The reference sensor is the one that is placed at the point that (in theoretical assumptions) is not a subject to vertical displacements and the displacements of controlled points are determined according to its height. The hydrostatic levelling rule comes from the Bernoulli’s law. While using the Bernoulli’s principle in hydrostatic levelling, the following components have to be taken into account: atmospheric pressure, force of gravity, density of liquid used in sensors places at CPs. The parameters mentioned above are determined with some mean errors that influence on the accuracy assessment of vertical displacements. In the subject’s literature, there are some works describing the individual accuracy analyses of the components mentioned above. In this paper, the author proposes the concept of comprehensive determination of mean error of vertical displacement (of each CPs), calculated from the mean errors’ values of components dedicated for specific HLS. The formulas of covariances’ matrix were derived and they enable to make the accuracy assessment of the calculations’ results. The author also presented the subject of modelling of vertical displacements’ gained values. The dependences, enabling to conduct the statistic tests of received model’s parameters, were implemented. The conducted tests make it possible to verify the correctness of used theoretical models of the examined object treated as the rigid body. The practical analyses were conducted for two simulated variants of sensors’ connections in HLS. Variant no. I is the sensors’ serial connection. Variant no. II relies on the connection of each CPs with the reference sensor. The calculations’ results show that more detailed value estimations of the vertical displacements can be obtained using variant no. II.


Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 133 ◽  
Author(s):  
Annika Jagels ◽  
Viktoria Lindemann ◽  
Sebastian Ulrich ◽  
Christoph Gottschalk ◽  
Benedikt Cramer ◽  
...  

The genus Stachybotrys produces a broad diversity of secondary metabolites, including macrocyclic trichothecenes, atranones, and phenylspirodrimanes. Although the class of the phenylspirodrimanes is the major one and consists of a multitude of metabolites bearing various structural modifications, few investigations have been carried out. Thus, the presented study deals with the quantitative determination of several secondary metabolites produced by distinct Stachybotrys species for comparison of their metabolite profiles. For that purpose, 15 of the primarily produced secondary metabolites were isolated from fungal cultures and structurally characterized in order to be used as analytical standards for the development of an LC-MS/MS multimethod. The developed method was applied to the analysis of micro-scale extracts from 5 different Stachybotrys strains, which were cultured on different media. In that process, spontaneous dialdehyde/lactone isomerization was observed for some of the isolated secondary metabolites, and novel stachybotrychromenes were quantitatively investigated for the first time. The metabolite profiles of Stachybotrys species are considerably influenced by time of growth and substrate availability, as well as the individual biosynthetic potential of the respective species. Regarding the reported adverse effects associated with Stachybotrys growth in building environments, combinatory effects of the investigated secondary metabolites should be addressed and the role of the phenylspirodrimanes re-evaluated in future research.


1966 ◽  
Vol 12 (5) ◽  
pp. 308-313 ◽  
Author(s):  
Albert W Opher ◽  
Charles S Collier ◽  
Joseph M Miller

Abstract A convenient electrophoretic procedure for the separation and quantitation of lactate dehydrogenase (LDH) isoenzymes is described. The system uses polyacetate Sepraphore III strips.* The areas of activity are shown by incubation with an LDH substrate combined with tetra-nitro-blue-tetrazolium. The reduction of the latter to the purple formazan is quantitatively related to the enzyme activity. Quantitative determination of the individual colored areas is performed by densitometry.


1973 ◽  
Vol 56 (6) ◽  
pp. 1475-1479 ◽  
Author(s):  
Ugo R Cieri

Abstract Sulfaquinoxaline is determined by its UV absorbance at about 358 nm, where the other 3 sulfonamides do not absorb. Sulfathiazole, sulfamerazine, and sulfamethazine are determined by a quantitative TLC procedure, based on the separation of the compounds on silica gel plates; the spots are extracted and the centrifuged extracts are analyzed spectro-photometrically. A method of calculating the total sulfonamide content, independent of the individual components, is also introduced.


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