bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulating and analyzing artificial nonstationary earthquake ground motions
Authors: Nau Robert F. , Oliver Robert M. , Pister Karl S. 
Published: June 2021

AbstractThis paper describes models used to simulate earthquake accelerograms and analyses of these artificial accelerogram records for use in structural response studies. The artificial accelerogram records are generated by a class of linear linear difference equations which have been previously identified as suitable for describing ground motions.The major contributions of the paper are the use of Kalman filters for estimating time-varying model parameters, and the development of an effective nonparametric method for estimating the variance envelopes of the accelerogram records.
Crust and upper mantle structure in the northwest Basin and Range province
Authors: Priestley Keith F. , Ryall Alan S. , Fezie Glenn S. 
Published: June 2021

abstractSeismic waves from nuclear explosions and from well-located local earthquakes have been recorded along several profiles through western Nevada, southeast Oregon, and eastern California. Pn delay times from these data and from additional travel times of NTS explosions recorded across the western Nevada seismic network have been interpreted in terms of varying crustal thickness of the western Great Basin. Our interpretation of these data implies that the crust thins from greater than 32 km thick in the vicinity of Mono Lake to 20 to 22 km thick over a broad region in northwest Nevada. The Pn headwave propagates to a distance of about 550 km with a velocity of 7.8 km/sec. At distances greater than 600 km a low velocity (7.44 km/sec), larger amplitude phase is observed. This phase may result from long-period energy diffracting into a shadow zone. A prominent, high-velocity second arrival following Pn by 1 to 2 sec in the distance range 340 to 475 km, is interpreted as a reflection from the base of the lithosphere at 60 to 70-km depth.
On the generalized exponential distribution of earthquake intensity and magnitude
Authors: Makjanić Berislav 
Published: June 2021

abstract
In continuation of a previous paper, a procedure to obtain the maximum likelihood values of the parameters for a generalized exponential distribution is described. The formula for the limits of confidence is also given. As an example, the maximum likelihood values of parameters for the initial and extremal distributions of Zagreb earthquakes and the limits of confidence for the largest possible intensity are presented.
Teleseismic analysis of the 1980 Mammoth Lakes earthquake sequence
Authors: Given Jeffrey W. , Wallace Terry C. , Kanamori Hiroo 
Published: June 2021

abstractThe source mechanisms of the three largest events of the 1980 Mammoth Lakes earthquake sequence have been determined using surface waves recorded on the global digital seismograph network and the long-period body waves recorded on the WWSSN network. Although the fault-plane solutions from local data (Cramer and Toppozada, 1980; Ryall and Ryall, 1981) suggest nearly pure left-lateral strike-slip on north-south planes, the teleseismic waveforms require a mechanism with oblique slip. The first event (25 May 1980, 16h 33m 44s) has a mechanism with a strike of N12°E, dip of 50°E, and a rake of −35°. The second event (27 May 19h 44m 51s) has a mechanism with a strike of N15°E, dip of 50°, and a slip of −11°. The third event (27 May, 14h 50m 57s) has a mechanism with a strike of N22°E, dip of 50°, and a rake of −28°. The first event is the largest and has a moment of 2.9 × 1025 dyne-cm. The second and third events have moments of 1.3 and 1.1 × 1025 dyne-cm, respectively. The body- and surface-wave moments for the first and third events agree closely while for the second event the body-wave moment (approximately 0.6 × 1025 dyne-cm) is almost a factor of 3 smaller than the surface-wave moment. The principal axes of extension of all three events is in the approximate direction of N65°E which agrees with the structural trends apparent along the eastern front of the Sierra Nevada.
Reservoir conditions related to induced seismicity at the Geysers steam reservoir, northern California
Authors: Denlinger Roger P. , Bufe Charles G. 
Published: June 2021

abstractSeismicity at The Geysers appears to be induced by steam production, in which water boils to steam within a pervasively fractured reservoir subject to high levels of tectonic shear stresses and strains.The steam reservoir is composed of fractured Franciscan graywacke with a very heterogeneous, multiple permeability and porosity distribution. Permeability is controlled by the larger fracture systems of the reservoir, which act as a very permeable conduit to less permeable rock containing liquid water. The reservoir fluid remains close to the liquidus conditions during production, implying both a temperature and pressure decline in the rock matrix bounding the fracture systems as the reservoir is depleted.Reservoir earthquake focal mechanisms are nearly aligned with the regional tectonic strain field, and reservoir earthquakes are indistinguishable from tectonic earthquakes elsewhere in the region. Within the reservoir, the volume defined by the earthquakes has not changed within the resolution of the seismic network from 1975 to 1979. The log moment per earthquake also has not changed, suggesting a steady-state process of stress buildup and release. Added to the zero correlation of the fluid injection history with the earthquake activity, the above observations suggest that elevated pore pressures and fluid injection are not likely causes for The Geysers induced seismicity.Instead, all available evidence points to the association of induced seismicity with pore pressure and temperature declines. The two most likely mechanisms are either an increase in local shear stress levels with fissure deflation, or a transition from stable to unstable sliding (“stick-slip”). No other documented mechanism for induced seismicity are consistent with in situ reservoir conditions at The Geysers.
Dynamic loads in the interior of a layered stratum: An explicit solution
Authors: Kausel Eduardo , Peek Ralf 
Published: June 2021

abstractThis paper presents an explicit, closed-form solution for the Green functions (displacements due to unit loads) corresponding to dynamic loads acting on (or within) layered strata. These functions embody all the essential mechanical properties of the medium and can be used to derive solutions to problems of elastodynamics, such as scattering of waves by rigid inclusions, soil-structure interaction, seismic sources, etc. The solution is based on a discretization of the medium in the direction of layering, which results in a formulation yielding algebraic expressions whose integral transforms can readily be evaluated. The advantages of the procedure are: (a) the speed and accuracy with which the functions can be evaluated (no numerical integration necessary); (b) the potential application to problems of elastodynamics solved by the boundary integral method; and (c) the possibility of comparing and verifying numerical integral solutions implemented in computer codes.
fmax
Authors: Hanks Thomas C. 
Published: June 2021

abstractThe title of this contribution refers to the high-frequency band-limitation of the radiated field of earthquakes. For close recording distances of ≃10 km, fmax for California earthquakes is generally found within the very narrow band 10 ≲ fmax ≲ 20 Hz, without regard to source strength or tectonic setting. Direct evidence for fmax (in the form of shear-wave acceleration spectral amplitudes) and indirect evidence as well (in the form of limiting spectral corner frequencies) have often been taken as manifestations of source properties, barrier end-zones, for example. This study concludes that fmax as actually observed is more likely to be a property of local site conditions, although this does not preclude source-controlled band-limitations at still higher frequencies. Observations of fmax for a single Oroville aftershock show a small but significant site-to-site variation that correlates well with gross surface geology; this variation is “normalized” with a demonstration that fmax for seven of the principal aftershocks (4.0 ≦ ML ≦ 4.9) at a single station has a distinctly smaller variation. Moreover, there seems to be nothing fundamental about the range 10 ≲ fmax ≲ 20 Hz so typical for California earthquakes; spectral shear-wave corner frequencies observed at very close distances (≲5 km) and for especially competent propagation paths are known to occupy the band 20 ≦ fo(S) ≦ 200 Hz.
Spectral attenuation ofSHwaves along the Imperial fault
Authors: Singh S. K. , Apsel R. J. , Fried J. , Brune J. N. 
Published: June 2021

abstractSpectral attenuation of SH waves has been studied to infer Q along the Imperial fault. The data set consists of six aftershocks of the Imperial Valley earthquake (15 October 1979, ML = 6.6) digitally recorded up to a distance of 51 km. Although there is large variance inQ−1 due to scatter in the data, Q below 3.75 km appears to be a function of frequency (increasing from about 60 at 3 Hz to 500 at 25 Hz). High Q values obtained at high frequencies strongly suggest that scattering has not removed a significant amount of energy from the signals and thus, the observed result, Q varying with frequency, is not due to scattering. For sources below 4 km the observed average SH-wave spectral amplitudes, A(f, R) along the fault can be fit by A ( f , R ) = S ( f ) R e − π f t * e − π f t / Q ( f ) where f is frequency, R is hypocentral distance, S(f) is source factor, Q(f) is quality factor below about 3.75 km, and t is travel time up to 3.75 km below the surface. The value of t* for the upper 3.75 km is probably between 0.027 and 0.047 (average Q between 100 and 60) depending upon the falloff of S(f) with f(f−3 or f−2) beyond the corner frequency.
A study of variations in the horizontal to verticalLgamplitude ratio in the Eastern United States
Authors: Gupta I. N. , von Seggern D. H. , Wagner R. A. 
Published: June 2021

abstractThree-component, short-period data on Lg in the Eastern United States show unusually large regional variations in the average value of the ratio of the largest horizontal (H) to the largest vertical (Z) component of ground motion. This ratio is found to have a value of about 3 or larger for most sites in the central platform and the coastal plains regions and less than 2 for the hard-rock sites in the Appalachian Mountains region. Large values of H/Z in the region of coastal plains sediments can be explained as being due to the presence of low-velocity overburden but such an explanation is probably not valid for sites in the central platform region. Large variations in H/Z from one site to another are of special importance in earthquake engineering since most damage to structures is generally caused by the horizontal components of ground motion.
New attenuation relations for peak and expected accelerations of strong ground motion
Authors: Bolt Bruce A. , Abrahamson N. A. 
Published: June 2021

abstractTwo proposals are presented on the estimation of maximum accelerations of strong ground motion near the causative fault. First, the crucial selection of the form fitted to observed accelerations as a function of distance from the source is discussed. In particular, evidence is given that the attenuation form adopted by Joyner et al. (1981) constrains the attenuation parameters so that inferences on near-fault motion and magnitude dependence are questionable. An alternative attenuation form is proposed which decouples far-field variations from near-field variations. Nonlinear least-squares regression to the same data set confirms the flattening of attenuation curves near to the source (&lt;10 km) in the magnitude range 5.0 &lt; M &lt; 7.0 and shows no indication (from the small amount of data available) of any additional increase in acceleration for M &gt; 7 earthquakes.For 6.0 ≦ M ≦ 7.7, the regression yieldsy = 1.6 { ( x + 8.5 ) 2 + 1 } − 0.19 exp { − 0.026 ( x + 8.5 ) }where y is the peak horizontal acceleration in g, and x (km) is the closest distance to the surface projection of the rupture.Second, a robust and easily computed parameter is defined for significant peak acceleration that meets many engineering requirements. This “effective” peak acceleration is obtained by developing histograms for the number of peaks and troughs on the observed record and by choosing the acceleration value at about the 90 percentile level. This truncation excludes scattered outliers of high-amplitude peaks not representative of the general distribution of the ground motion amplitudes. Corresponding values for “effective peak acceleration” are tabulated for part of the basic data set, and it is demonstrated that the scatter about the attenuation regression line is reduced using the proposed parameter.
PEMBELAJARAN SEJARAH DI ERA REVOLUSI INDUSTRI 4.0
Authors: Agung Dewa Agung Gede 
Published: June 2021

Industrial Revolution 4.0 influences historical learning both in substance and in the learning process. This development starts from materials, methods, media, innovative learning models, and especially substances that often cause controversy. The development of technology causes a variety of historical information easily obtained. History lessons should follow these developments, although not all of them have a positive impact on students, history teachers, and historians. They must be able to be selective in responding to various developments in the availability of historical information. Collaboration and elaboration between history and other fields of science are necessary to see various changes and developments in society. History needs to be viewed in a multiperspective manner rather than a mono perspective. Thus, the learning history will provide comprehensive and integrated information that produces the total history. Therefore, this paper provides an alternative way of learning history in the Era of Industrial Revolution 4.0.
The Online Social Support of Chinese Fellow Townsman in Post Pandemic
Authors: Gao Ning 
Published: June 2021

As a kind of disease risk, the global spread of the COVID-19 may just be a microcosm of the global risk society. Affected by the epidemic, people adopt more online virtual connections and have become more dependent on social media. This paper conducted the online social support of Chinese fellow-townsman analysis via conducting online participatory observations on the QQ group of Xinhua immigrants and conducting in-depth interviews with 15 of them. This study found that the social support obtained by the Chinese Fellow Townsman through the Internet interpersonal mutual aid network has made up for the shortcomings of formal social support to a certain extent. In the risk society, it helps individuals get immediate and personalized help. In terms of online social support sources, the Internet social support of Chinese Fellow Townsman mainly comes from bridging social capital. From the perspective of online support content, the online social support of this group is mainly manifested in emotional support, companionship support, and informational support, and the role of tangible support is relatively weak. As to the support effect, through the Online social support from the group, the peers can obtain timely, diverse, and non-redundant information to help them make better decisions. But the ability of interpersonal networks to provide resources is limited. When necessary, we still need social support from the government and other formal organizations.
Quantitative analysis of optical coherence tomography in age related macular degeneration
Authors: Sukanya D , Sudha R , Sushma K , Sreya V 
Published: June 2021

Age related macular degeneration (ARMD) is a common degenerative disorder of macula in people above 50 years. The dry and wet/neovascular forms can lead to loss of vision. Optical coherence tomography is a popular tool in the diagnosis of AMRD. Aim of the study is to assess the Optical Coherence Tomography to diagnose the Age Related Macular Degeneration in a tertiary care centre. This prospective hospital based study was conducted on 50 patients presenting with age related macular degeneration clinically (100 eyes). Inclusion criteria was patients newly diagnosed clinically as ARMD and on no treatment. Exclusion criteria was Patients already diagnosed ARMD and on treatment, Patients with other retinal and macular diseases, and previous laser treatment. There were 42(84%) of patients are of 50-70 years age. Males were 21, and females were 29 without significant difference (p=0.7). Out of 100 eyes, 32% diagnosed as wet ARMD and 60% eyes had dry ARMD Dry ARMD is common in females (34%) and wet ARMD common in males (26%). In dry ARMD cases, 77.04% eyes had drusen by OCT, and 72.72% eyes had classic Choroidal neovascular membranes (CNVM). OCT showed sub-foveal CNVM as the common type of classic CNVM. 16 men were smokers, and 36 patients have hypertension. Smoking was significantly associated with ARMD (P &#60; 0.05). Increased prevalence of wet ARMD in males due to smoking, which leads to risk for CNVM. Smoking was significantly associated with ARMD (P &#60; 0.01) in our study. The prevalence was increased with increasing age. Dry ARMD was much more common than Wet ARMD, and both types increased in frequency with increasing age. ARMD is more common in females. OCT is highly specific in detecting the early sub-retinal neo vascular membrane and to assess the activity of neovascular membranes in early wet ARMD.
A study on digital eye strain among patients attending at one of the tertiary care hospitals of Saurashtra region, Gujarat
Authors: Modi Varsha M 
Published: June 2021

Digital Eye Strain (DES) is a group of eye and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use. Majority of scientific literature available for DES has targeted only youth/young people, overlooking rest age-groups.Aim of this study was to assess the prevalence of DES and its various risk factors of digital device usage pattern and to correlate them statistically with clinical features. The study was conducted at medical college attached hospital in Amreli district, Gujarat, India during June – September 2020. Total 320 study participants were included in research. All patients attending ophthalmic OPD during study –period were screened for DES related symptoms and history of digital device usage. Information collected for socio-demographic profile, pattern of device usage and reported clinical features. Data were entered in MS Excel and analyzed through SPSS software. Majority of study participants (47.81%) belonged to 18-30 years’ age-group, 186(58.13%) were males. Major symptoms of DES reported were: Headache (77.81%) dry-eye (61.56%), Temporary Difficulty in gaze (51.25%), Red-eye (49.37%) and blurred vision (44.68%). Of total, 59.06% and 9.06% respectively used digital device for 4-6 hours and &#62;6 hours per day. Approximate screen distance &#60;50 cm. from eyes was preferred by 192(60%) participants. Bright contrast setting was preferred by majority (253, 79.05%). Taking break after 30 minutes of continuous usage was preferred by 84 (26.25%) participants. Role of age and gender was found statistically significant in occurrence of many of symptoms of DES. Approximate distance of digital device from eyes revealed significant association with burning, dry and red eyes, headache and temporary difficulty in gaze. Taking preferred break after 30 minutes of continuous usage of digital device, all clinical symptoms revealed significant association except double vision. Dry eyes, temporary difficulty in gaze and blurred vision revealed comparatively more risk with pattern optical aid usage.
To stop or to continue aspirin prior to manual small incision cataract surgery
Authors: Madhuri P  , Pooja H V  , Gowda H T Venkate 
Published: June 2021

To ascertain whether to stop or continue aspirin before cataract surgery. Prospective observational study from July 2018 to June 2019. Information on pre-existing medical conditions like cardiac disease/stroke & use of Aspirin was obtained from patients posted for cataract surgery. Physical examination was done by physician & decided whether aspirin has to be stopped before surgery. Intra-operative and post-operative outcomes were recorded. SPSS 20.0 by using descriptive statistics i.e. only frequency and percentage. Out of 64 patients, 38 discontinued aspirin and 26 continued. In the group of patients who discontinued aspirin, 2 had bleeding complication in the form of bleeding from cut ends of conjunctiva. Where as in the group who continued aspirin 4 patients had bleeding complication. No thromboembolic events were recorded in both the groups. The risk of medical & ophthalmic events surrounding cataract surgery were so low that absolute differences in risk associated with changes in Aspirin use were minimal.
New Border Studies On Israel/Palestine: Review of Two Books
Authors: Meier Daniel 
Published: June 2021

Review essay on The Politics of Maps: Cartographic Constructions of Israel/Palestine by Christine Leuenberger & Izhak Schnell and Penser la Palestine en réseaux by Véronique Bontemps, Nicolas Dot-Pouillard, Jalal al-Husseini & Abaher al-Sakka.
Igualdad de Trato y No Discriminación: conceptualización, víctimas y ámbitos en Euskadi.
Authors: Sancosmed Cámara Imanol , Sabana Bisoko Diogenes 
Published: June 2021

<p>La diversidad cultural es uno de los rasgos característicos de las sociedades contemporáneas, donde la coincidencia de personas con diversos orígenes étnico – raciales o diversidad sexoafectiva (entre otros) ha traído aparejado el reto de la gestión positiva de la diversidad.</p><p>Para ello, se ha desarrollado un corpus jurídico a nivel internacional, nacional y autonómico que atienda a la protección de dos derechos clave, como son el derecho a la Igualdad de Trato y el derecho a la diferencia, con el fin de garantizar el pleno desarrollo de las personas y colectivos que conforman nuestras sociedades.</p><p>A pesar de que Euskadi es una sociedad abierta a la diversidad, algunos datos señalan la presencia de algunas formas discriminatorias en diferentes ámbitos y por parte de distintos agentes. El objetivo del presente artículo es ofrecer una visión general sobre esta realidad, tomando diferentes fuentes que ayuden a ofrecer una fotografía del fenómeno lo más completa posible.</p>