bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase analysis of Rayleigh waves from the Shagan River test site in the USSR
Authors: Herrin Eugene , Goforth Tom 
Published: July 2021

AbstractA study was made to determine if significant phase differences exist between Rayleigh waves which have traveled almost identical paths from the USSR Shagan River test site. Surface waves from five explosions recorded at six SRO/ASRO digital stations were used in the analysis. The explosion of 4 August 1979 was selected as a reference, and at each site the phase spectra of the Rayleigh waves from the other five events were compared to that of the reference. The technique of phase-matched filtering was used to analyze the signals. This technique reduces the effects of multipathing and removes phase differences due to dispersion along slightly different travel paths.Each epicenter had been relocated by using calibration data from the cratering shot of 15 January 1965, and remaining errors in location and origin time are considered to be extremely small. Seismograms were analyzed for surface waves recorded at: Matsushiro, Japan (MAJO); Shillong, India (SHIO); Kabul, Afghanistan (KAAO); Ankara, Turkey (ANTO); Grafenburg, West Germany (GRFO); and Albuquerque, New Mexico (ANMO).Results of the study indicate that Rayleigh waves from some Shagan River explosions have undergone large phase shifts relative to Rayleigh waves which have traveled almost identical paths from other Shagan River explosions. In some cases, the phase shifts can be interpreted as complete phase reversals with associated time delay. In particular, as compared to the explosion of 4 August 1979, Rayleigh waves from the explosion of 7 July 1979 are reversed in polarity at KAAO and ANTO and are reversed in polarity and delayed at GRFO, SHIO, and MAJO.
Apparent stresses, stress drops, and amplitude ratios of earthquakes preceding and following the 1975 HawaiiMS= 7.2 main shock
Authors: Zuñiga F. R. , Wyss M. , Wilson M. E. 
Published: July 2021

AbstractS-wave spectra for approximately 300 earthquake signals (2.8 ≦ ML ≦ 3.9) were obtained from hand-digitized Wood-Anderson records from Hilo, Hawaii. All sources were located within part of the rupture volume of the 1975 Hawaii MS = 7.2 earthquake. The epicentral distance to Hilo was about 45 ± 3 km, the backazimuth was 180° ± 10° (south), and the sources were located at depths of 9 ± 1.4 km. The apparent stress and Brune stress drop, based on 3-sec windows of the S waves, were examined for possible temporal and spatial dependence. Most of the data showed a remarkable constancy of the average apparent stress and stress drop per event as a function of time. No measurable change in average signal content took place at the time of the main shock. A statistically significant difference in the average stress parameters per event was found between neighboring subvolumes (radius ≈ 5 km) of the 1975 aftershock zone: a volume previously proposed as asperity based on seismicity pattern interpretation contained earthquakes with higher apparent stresses of ησ=9.0±8.8 bars compared to the neighboring volume with ησ = 4.2 ± 6.1 bars. Seventy-eight spectra obtained from a second station showed the same difference between the two volumes as that found at station Hilo, suggesting that the signal differences should be interpreted in terms of source differences. In addition, amplitude ratios of SV/P waves measured at Hilo showed that a systematic difference of 10° in fault plane orientation existed during years before the 1975 main shock. This agrees with the rotation of the fault plane during the main rupture reported elsewhere. We hypothesize that heterogeneities along the fault plane with dimensions of about 5 km cause changes in fault plane dip, differences in average stress release per earthquake, strong contrasts in seismicity patterns, and differences in aseismic strain release by fault creep. These same heterogeneities in the fault plane apparently also control the location of major earthquakes and the complexity of their ruptures.
A fast algorithm for two-point seismic ray tracing
Authors: Um Junho , Thurber Clifford 
Published: July 2021

Abstract
A new approximate algorithm for two-point ray tracing is proposed and tested in a variety of laterally heterogeneous velocity models. An initial path estimate is perturbed using a geometric interpretation of the ray equations, and the travel time along the path is minimized in a piecewise fashion. This perturbation is iteratively performed until the travel time converges within a specified limit. Test results show that this algorithm successfully finds the correct travel time within typical observational error much faster than existing three-dimensional ray tracing programs. The method finds an accurate ray path in a fully three-dimensional form even where lateral variations in velocity are severe. Because our algorithm utilizes direct minimization of the travel time instead of solving the ray equations, a simple linear interpolation scheme can be employed to compute velocity as a function of position, providing an added computational advantage.
Source parameter analysis from strong motion records of the Friuli, Italy, earthquake sequence (1976-1977)
Authors: De Natale Giuseppe , Madariaga Raul , Scarpa Roberto , Zollo Aldo 
Published: July 2021

AbstractTime and frequency domain analyses are applied to strong motion data recorded in Friuli, Italy, during 1976 to 1977. An inversion procedure to estimate spectral parameters (low frequency level, corner frequency, and high frequency decay) has been applied to displacement spectra using a simple earthquake source model with a single corner frequency.The data were digitized accelerograms from ENEA-ENEL portable and permanent networks. Instrument-corrected SH waves were selected from a set of 138 three-component, hand-digitized records and 28 automatically digitized records. Thirty-eight events with stations having 8 to 32 km epicentral distance were studied.Different stress drop estimates were performed showing high values (200 to 300 bars, on the average) with seismic moments ranging from 2.8 × 1022 to 8.0 × 1024 dyne-cm.The observation of systematic higher values of Brune stress drop (obtained from corner frequencies) with respect to other time and frequency domain estimates of stress release, and the evidence on time series of multiple rupture episodes suggest that the observed corner frequencies are most probably related to subevent ruptures rather than the overall fault size.Seven events recorded at more than one station show a good correlation between rms, Brune, and dynamic stress drops, and a constant scaling of this parameter as a function of the seismic moment. When single station events are also considered, a slight moment dependence of these three stress drop estimates is observed differently. This may be explained by an inadequacy of the ω−2 high-frequency decay of the source model or by high-frequency attenuation due to propagation effects.The high-frequency cutoff of acceleration spectra indicates the presence of an Fmax in the range of 5 to 14 Hz, except for the stations where local site effects produce spectral peaks.
Source characteristics of earthquakes in the Michoacan seismic gap in Mexico
Authors: Astiz Luciana , Kanamori Hiroo , Eissler Holly 
Published: July 2021

AbstractWe investigated the source characteristics of large earthquakes which occurred in the Michoacan, Mexico, seismic gap during the period from 1981 to 1986 in relation to historical seismicity in the region. The rupture pattern of the Michoacan gap during this period can be characterized by a sequential failure of five distinct asperities. Before 1981, the Michoacan gap had not experienced a large earthquake since 1911 when an MS = 7.8 earthquake occurred. The recent sequence started in October 1981 with the Playa Azul earthquake which broke the central part of the gap. Body-wave modeling indicates that the Playa Azul earthquake is 27 km deep with a seismic moment of 7.2 × 1027 dyne-cm. It is slightly deeper than the recent Michoacan earthquakes, and its stress drop is higher, suggesting a higher stress level at depths in the Michoacan gap. The seismic moment of the 19 September 1985 (Mw = 8.1) earthquake was released in two distinct events, with the rupture starting in the northern portion of the seismic gap and propagating to the southeast with low moment release through the area already broken by the 1981 Playa Azul earthquake. The rupture propagated further southeast with an Mw = 7.5 event on 21 September 1985. Another aftershock occurred on 30 April 1986 to the northwest of the 19 September main shock. Body-wave modeling indicates that this event has a simple source 10 sec long at 21 km depth, and fault parameters consistent with subduction of the Cocos plate (ϑ = 280°, δ = 12°, and λ = 70°) and M0 = 2.0 to 3.1 × 1026 dyne-cm (Mw = 6.8 to 6.9). Although this distribution of asperities is considered characteristic of the Michoacan gap, whether the temporal sequence exhibited by the 1981 to 1986 sequence is also characteristic of this gap or not is unclear. It is probable that, depending on the state of stress in each asperity, the entire gap may fail in either a single large event with a complex time history or a sequence of moderate to large events spread over a few years. The seismic moment and the time since the last earthquake in Michoacan (in 1911) fit an empirical relation between moment and recurrence time found for the Guerrero-Oaxaca region of the Mexico subduction zone.
Seismic imaging of the site response using microearthquake recordings. Part I. Method
Authors: Scherbaum Frank 
Published: July 2021

AbstractMicroearthquake signals from widely distributed geographical regions have been noticed repeatedly to be strongly affected by local site effects. The corresponding seismograms contain important information on the individual propagation path. A single station inversion method is presented which allows the imaging of the subsurface impedance structure from locally recorded SH waves records.The technique is based on the Kunetz-Claerbout equation which in its original form states the relationship between the transmission response and the reflection response for P waves in a horizontally layered medium and vertical incidence (Claerbout 1968). By adapting Claerbout's formulation to the transmission problem for SH waves under oblique incidence, microearthquake recordings can be used to calculate corresponding pseudo-reflection seismograms which in turn can be inverted for the impedance structure by exploiting Levinson recursion.Limitations in the high-frequency content of the signals due to the combined effects of absorption, recording system, and bandlimited source signals, as well as the influence of noise, drastically reduce the resolutional power of the inversion procedure. A number of different deconvolution techniques have been tested with synthetic seismograms for the applicability to reduce these effects. Good results have been obtained with the blind deconvolution technique of Scherbaum and Stoll (1985), utilizing the minimum phase property of the Green's function.From the analysis of synthetic data, it can be expected that for realistic source-receiver situations and short-period recording systems, the main reflectors down to a depth of several hundreds of meters could be resolved.
Seismic imaging of the site response using microearthquake recordings. Part II. Application to the Swabian Jura, southwest Germany, Seismic network
Authors: Scherbaum Frank 
Published: July 2021

Abstract
The subsurface site structure of the Swabian Jura, southwest Germany, seismic network has been modeled from the inversion of locally recorded SH wave microearthquake seismograms. The observed records have been deconvolved from the effects of apparent source pulse broadening due to the combined influence of frequency bandlimited source signals, absorption, peg leg multiple reflections, and the recording system following the procedure of Scherbaum and Stoll (1985). Corresponding pseudo-reflection seismograms were calculated based on the Kunetz-Claerbout relation for SH waves and inverted using a Levison recursion algorithm. The final structural models have been optimized in terms of numbers of layers and depth resolution using Ferber's (1985) noise stabilization technique.
The resulting impedance models for the Swabian Jura, southwest Germany, seismic network show some strongly correlated reflectors in the uppermost layers, which are well understood in terms of the local stratigraphy. The comparison of the inverted impedance model HSN with the P-wave velocity log from a nearby exploration drilling (Trochtelfingen, BEB) shows a high degree of similarity of the dominating reflectors down to a depth of several hundred meters.
As a consequence, the coda-generating process for the early part of the coda of the observed Swabian Jura microearthquake seismograms (Wood-Anderson magnitude MWA &lt; 3.0) can be completely interpreted as an effect of the local subsurface structure.
Efecto del mezclado en la solubilidad de las prolaminas de maíz y en las propiedades reológicas de sus masas durante el procesamiento para la producción de tortilla
Authors: Torres Chavez Patricia Isabel 
Published: July 2021

El estudio tiene como objetivo investigar los efectos del mezclado sobre la solubilidad de las proteínas del maiz y su estructura secundaria, en masas de maíz durante el procesamiento para la producción de tortillas. Para evaluar cómo el mezclado afecta la reología de la masa, se determinaron los módulos de almacenamiento (G´), los módulos de pérdida (G´´) y el ángulo de fase (Tan d) dependientes de la frecuencia y el perfil de textura (TPA). Los análisis cromatográficos (HPLC-SEC) mostraron una mayor proporción de proteínas poliméricas solubles (especies solubles de peso molecular alto). Los resultados de FT-IR revelaron que la mezcla promueve el aumento de la estructura de la hoja b y la reducción de la proporción de la hélice a, lo que sugiere la agregación de las proteínas. Los datos reológicos mostraron que en las masas de maíz prevaleció el comportamiento elástico sobre el viscoso (G´ > G´´), un material sólido, blando con una estructura ordenada y estable. El mezclado, un paso intermedio para la producción de masa, tuvo efectos importantes en la estructura de la proteína y las propiedades reológicas de la masa, el aumento de Tan d es consistente con un mayor carácter viscoso y agregación de polímeros que se demostró en este caso para las proteínas.
Evaluation of biochemical, chemical, physical and microbiological quality of tilapia (Oreochromis niloticus) muscle during storage at 0 and 5 °C
Authors: Montoya Camacho Nathaly , Castillo-Yáñez Francisco Javier , Márquez-Ríos Enrique , Ruíz-Cruz Saúl , Arvizu-Flores Aldo Alejandro , Barrales-Cureño Hebert Jair , Jiménez-Ruíz Edgar Iván , Sánchez-Herrera Leticia Mónica , Ocaño-Higuera Víctor Manuel 
Published: July 2021

Fishing products are characterized for being highly perishable; therefore, preservation methods are used to retain freshness and quality and extend shelf life. One of the factors that most impact the loss of freshness, quality, and shelf life is storage temperature. This study evaluated the effect of storage temperature (0 ºC and 5 °C) on the quality and shelf life of tilapia (Oreochromis niloticus) muscle during 20 days of storage. Adenosine 5’-triphosphate (ATP) and related compounds, K-value, pH, color, texture, water holding capacity (WHC), total volatile bases (TVB-N), and total count of mesophilic microorganisms were monitored. Both time and storage temperature had a significant effect (P < 0.05) on the K-value, TVB-N, and total count of mesophilic microorganisms. The overall results of this study indicated that the edible quality of tilapia muscle was affected by storage temperature, observing a shelf life of 16 days at 0°C and 8 days at 5 ºC.
Evaluation of the Level of Financial Inclusion among Businesses from the Next 11 Group of Countries
Authors: Puszer Blandyna , Cichorska Joanna 
Published: July 2021

The purpose of the article. The article aims to evaluation which factors are a barrier to financial inclusion in the Next 11 countries. The research aim of this article is to assess the differences in the degree of financial inclusion of business entities from the Next 11 group of countries by taking into consideration the use of basic banking services such as bank accounts, credit lines and loans.
The hypothesis of the article. The authors put forward the hypothesis that in poorly developed countries, to which the Next 11 countries belong, there are considerable areas of financial exclusion among businesses, in particular among small and medium-sized enterprises. In most of these countries, corporate financial inclusion rates are below the global average.
Methodology. The article applies the following research methods: a critical analysis of the literature in the theoretical part; and desk research analysis (that is analysis of data gathered) in the empirical part. Research into the degree of financial inclusion in Next 11 countries was conducted on the basis of indicators of the use of banking services by enterprises operating in Next 11 countries.
Results of the research. The level of companies’ financial inclusion depends above all on the degree to which they make use of bank accounts and bank loans. Countries in different geographical locations vary in terms of economic and technological development and social awareness, which impacts on their participation in the use of banking services.
Analysis of the basic indicators of banking services availability showed that there is a widespread problem of financial exclusion for companies in Next 11 countries. The proportion of companies possessing a current bank account was below the average of all countries worldwide. However, the worst situation exists in the field of financing business activity using foreign capital. Credit lines there are used on average by less than 25% of companies. However, Next 11 group countries do not see the lack of available credit lines as the main barrier to development.
Effectiveness of using Gebar modules (The Movement of Line Marching) for students in elementary school
Authors: Indrawati Delia , Hasanah Uzlifatul , Mariana Neni , Wicaksono Vicky Dwi , Siwi Dwi Anggraeni , Purbosari Para Mitta , Fanny Arif Mahya 
Published: July 2021

One innovation that can be developed based on the problem learning angle created is the movement of line marching skills as learning media alternatives for students. This study aims to determine the effectiveness of using the Gebar Modules. The sample comprised 30 students from grades 4A and 4B who were randomly selected with one-group pre-test–post-test design. The result showed that the designed module is feasible to use. First, the data show that the N-gain coefficient is 0.77, which indicates the module’s effectiveness on student-learning outcomes. Another data collection showed that 82% of the students could use a bow properly and 62% of the students can perform drill movements with the appropriate rules. In conclusion, this module makes students not only observe the things that shape the angle but also those that give them an angular shape by themselves so the material is etched deeper in their memory.

Keywords: Gebar module, learning outcomes, THE movement of line marching skills
Pengembangan Perangkat dengan Model Pembelajaran Advance Organizer untuk Meningkatkan Penguasaan Konsep dan Retensi Fisika Peserta Didik
Authors: Fitria Syari'atul , Harjono Ahmad , Gunawan Gunawan , Ayub Syahrial 
Published: July 2021

This research aims to determine the feasibility of a device with an advance organizer learning model to improve student’s mastery of concepts and physics retention. Learning device developed include syllabus, lesson plans, student worksheet, concept maps, concept mastery and physics retention test instruments. The research design used is Research and Development (R&D) with the 4D model (define, design, develop & disseminate). This research is limited only to the development stage, namely validation by a validator with supporting data in the form of student responses to the developed device. The results of validation using CVR and CVI show that the device is in the very feasible category. The response results showed an average percentage of 99% with very good category. Thus, it can be concluded that the device developed is very suitable for use in learning physics and is predicted to increase the mastery of concepts and student retention.
Pengembangan Perangkat Pembelajaran Dengan Model Reciprocal Teaching Untuk Meningkatkan Hasil Belajar Fisika Peserta Didik
Authors: Yusna L. Muh. Agri , Harjono Ahmad , Ayub Syahrial , Wahyudi Wahyudi 
Published: July 2021

Penelitian ini bertujuan untuk mengetahui kelayakan produk perangkat pembelajaran dengan model reciprocal teaching untuk meningkatkan hasil belajar fisika peserta didik. Penelitian ini menggunakan metode penelitian Research and Development (R&D) dengan model penelitian 4D Models yang terdiri dari tahap pendefinisian (Define), perancangan (Desain), pengembangan (Develop), dan penyebaran (Disseminate). Kelayakan perangkat pembelajaran yang dikembangkan dilihat dari hasil rata-rata perhitungan skor penilaian enam ahli yang dihitung dengan validitas dan reliabilitas perangkat. Selanjutnya dilakukan penyebaran angket respon pada mahasiswa S1 pendidikan fisika FKIP, Universitas Mataram. Hasil penelitian berdasarkan penilaian ahli menunjukkan bahwa hasil pengembangan perangkat pembelajaran memiliki nilai kelayakan dengan kriteria cukup valid dan reliabel pada Silabus, RPP, Materi Ajar, LKPD dan instrumen tes yang dikembangkan. Hasil respon mahasiswa dan peserta didik menunjukkan respon sangat baik sehingga, dapat disimpulkan perangkat pembelajaran dengan model reciprocal teaching layak dilanjutkan ke tahap uji coba dalam proses pembelajaran untuk meningkatkan hasil belajar fisika peserta didik.
Acerca de Capital e ideología, de Thomas Piketty
Authors: Escobar Toledo Saúl 
Published: July 2021

Reseña bibliográfica de:
Thomas Piketty (2019). Capital et idéologie. París: Editions du Seuil. Versión en español: (2020). Capital e ideología (trad. de Daniel Fuentes). México: Grano de Sal.