bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the synthesis of shear-coupled PL waves
Authors: Chander Ramesh , Alsop L. E. , Oliver Jack 
Published: July 2021

ABSTRACT
Using the shear-coupled PL wave hypothesis of Oliver as a basis, a method is developed for computing synthetic long-period seismograms between the onset of the initial S-type body phase and the beginning of surface waves. Comparison of observed and synthetic siesmograms shows that this hypothesis can explain, in considerable detail, most of the waves with periods greater than about 20 sec recorded during this interval. The synthetic seismograms are computed easily on a small digital computer; they resemble the observed seismograms much more closely than the synthetic seismograms obtained through the superposition of normal modes of the Earth that have been reported in the literature. The synthesis of shear-coupled PL waves depends on a precise knowledge of the phase-velocity curve of the PL wave and travel-time curves of shear waves. Hence, in principle, if one of these quantities is well-known the other can be determined by this method. Phase-velocity curves of the PL wave are determined for the Baltic shield, the Russian platform, the Canadian shield, the United States, and the western North-Atlantic ocean, on the assumption that J-B travel-time curves of shear waves apply to these areas. These dispersion curves show the type of variations to be expected on the basis of the current knowledge of the crustal structures in these areas. Examples are presented to show that J-B travel-times of shear waves along paths between Kenai Peninsula, Alaska and Palisades, equatorial mid-Atlantic ridge and Palisades, and Kurile Islands and Uppsala need to be revised. Shear-wave travel-time curves that are not unique for reasons explained in the study but that give synthetic seismograms in agreement with the observed seismograms were obtained. The new S curves are compared with the J-B travel-time curves for S; and they all predict S waves to arrive later than the time given by J-B tables for epicentral distances smaller than about 30°. The new S curve for the Alaska to Palisades path appears to agree with one of the branches of a multi-branched S curve proposed recently by Ibrahim and Nuttli for the ‘average United States’ insofar as travel-times are concerned, but there are some differences in the slopes of the two curves.
The Fairbanks earthquakes of June 21, 1967; aftershock distribution, focal mechanisms, and crustal parameters
Authors: Gedney Larry , Berg Eduard 
Published: July 2021

Abstract
A series of moderately severe earthquakes occurred in the vicinity of Fairbanks, Alaska, on the morning of June 21, 1967. During the following months, many thousands of aftershocks were recorded in order to outline the aftershock zone and to resolve the focal mechanism and its relation to the regional tectonic system. No fault is visible at the surface in this area.
Foci were found to occupy a relatively small volume in the shape of an ablate cylinder tilted about 30° from the vertical. The center of the zone lay about 12 kilometers southeast of Fairbanks. Focal depths ranged from near-surface to 25 kilometers, although most were in the range 9-16 km. In the course of the investigation, it was found that the Jeffreys and Bullen velocity of 5.56 km/sec for the P wave in the upper crustal layer is very near the true value for this arec, and that the use of 1.69 for the Vp/Vs ratio gives good results in most cases.
The proposed faulting mechanism involves nearly equal components of right-lateral strike slip, and normal faulting with northeast side downthrown on a system of sub-parallel faults striking N40°W. The fault surface appears to be curved—dipping from near vertical close to the surface to less steep northeast dips at greater depths. The relationship of this fault system with the grosser aspects of regional tectonism is not clear.
Travel times and amplitudes of S waves from nuclear explosions in Nevada
Authors: Nuttli Otto W. 
Published: July 2021

Abstract
The underground Nevada explosions HALF-BEAK and GREELEY were unique in creating relatively large amplitude and long-period body S waves which could be detected at teleseismic distances. Observations of the travel times of these S waves provide a surface focus travel-time curve which in its major features is similar to a curve calculated from the upper mantle velocity model of Ibrahim and Nuttli (1967). This model includes a low-velocity channel at a depth of 150 to 200 km and regions of rapidly increasing velocity beginning at depths of 400 and 750 km. Observations of the S wave amplitudes suggest that a discontinuous increase in velocity occurs at 400 km, whereas at 750 km the velocity is continuous but the velocity gradient discontinuous.
Body wave magnitudes calculated from S amplitudes are 5.3 ± 0.2 for GREELEY and 4.9 ± 0.2 for HALF-BEAK. These are about one unit less than body wave magnitudes from P amplitudes as reported by others.
The shape and orientation of the radiation pattern of SH for both explosions are consistent with the Rayleigh and P-wave amplitude distribution of BILBY as given by Toksoz and Clermont (1967). This suggests that the regional stress field is the same at all three sites, and that the direction of cracking as well as the strain energy release in the elastic zone outside the cavity is determined by the regional stress field.
The composition of P codas using magnetic tape seismograms
Authors: Basham P. W. , Ellis R. M. 
Published: July 2021

abstract
The short-period P codas of 41 seismic events recorded on the plains of western Alberta are examined for compressional and shear phases. A non-linear “P-Detection” polarization filter is applied to 25 seconds of the records following the P onset. Numerous compressional wave signal pulses are detected amid the codas; these include PcP and PKP phases for events at appropriate distances and the common depth phases pP and sP. The phase pP is detected on the records of 25 events, 16 of which have reported depths shallower than 40 km. For events with pP visible at two stations, pP-P times are accurate to about ±1 second, allowing focal depth assignment to an accuracy of about ±15 km. Locally-generated shear phases are studied using particle-motion plots in the vertical (vertical-radial) and horizontal planes. There are large variations in SV/P amplitude ratios for individual events at stations separated by 60 to 160 km. Anomalous SV and SH-type motions are attributed to a complex Precambrian basement.
Dynamic elasto-plastic response of a reinforced concrete spandrel frame
Authors: Walpole W. R. , Shepherd R. 
Published: July 2021

abstract
Following the construction of the sixteen story Jerningham Apartments building in Wellington, New Zealand, small amplitude shaking tests were conducted on the building and the development of an inelastic analysis procedure enabled the possible elastoplastic response of a portion of the reinforced concrete framework to be investigated using a digital computer. In this paper the correlation between the predicted and measured periods of elastic vibration is briefly referred to and the results of elastic and elasto-plastic analyses of the selected portion of the spandrel beam frame are presented.
Excitation of mantle Love waves and definition of mantle wave magnitude
Authors: Brune James N. , Engen Gladys R. 
Published: July 2021

abstract
A study is made of the excitation of mantle Love waves of 100 seconds period as a function of magnitude. 153 measurements of Love wave spectral density for earthquakes since 1930 ranging in magnitude from 6.0 to 8.9 are used to determine an excitation curve. The observations were first corrected to a standard distance of 90°. The excitation curve supports earlier results for mantle Rayleigh waves and, for strike-slip motion, an earlier curve for seismic moment versus mantle-wave magnitude. For dip-slip motion, the moments should be multiplied by a factor of about 212. A definition of mantle wave magnitude MM, is set up, and the largest earthquake since 1930 found on this scale is the Alaskan earthquake of March 28, 1964 where MM = 8.9. Other comparably large earthquakes, MM = 8.8, were the Kamchatka earthquake of November 4, 1952 and the Chilean earthquake of May 22, 1960. It is suggested that mantle-wave magnitudes be used as a diagnostic aid in estimating the Tsunami potential of earthquakes.
The design of electromagnetic damping circuits
Authors: Rihn W. J. 
Published: July 2021

Abstract
This paper describes a method for determining the size of the magnet required for coil-magnet transducers directly from the seismic mass, period, and damping. It is shown that the coil wire size and resistance do not influence the size of the magnet. To achieve the desired generator constant, it is immaterial whether the transducer is designed with a large flux density and short wire length, or with a small flux density and long wire length. It is also shown that the transducer is more efficient when the entire coil is immersed in the magnetic field rather than having the coil extend beyond the pole pieces.
Effect of an elastically-restrained boundary on dilatational wave radiation patterns
Authors: Huang Y. T. 
Published: July 2021

abstract
In this paper, the effect of a boundary restraint, peculiar to the local geology, on dilatational wave radiation patterns is studied for an arbitrary combination of the Lamé constants of the Earth. Depending upon the degree of boundary restraint, significant change in radiation patterns can take place. This phenomenon is probably related to amplitude anomalies often observed in field records. General solutions are given for a homogeneous, isotropic half space.
The S velocity at the core-mantle boundary, from observations of diffracted S
Authors: Cleary John 
Published: July 2021

abstract
A regression line has been fitted to times of diffracted S observed at Canberra from 11 earthquakes. When corrections are made to the observed times to compensate for probable mislocations of the earthquakes, a value of 8.9 sec/deg is obtained for the travel time gradient, with a 95 per cent confidence interval estimate of 0.2 sec/deg. Assuming a core radius of 3473 km, this corresponds to an S velocity at the core-mantle boundary of 6.8 km/sec. This is 0.5 km/sec lower than the value given by Jeffreys (1939). The analysis also provides an estimate of the S time at 100° distance which is about 12 sec greater than that given in the Jeffreys-Bullen tables.
The results suggest that current models of the lowest part of the mantle are significantly in error. Revision of the model in this region should enable a more satisfactory reconciliation with free oscillation data.
Dislocation models and seismomagnetic calculations for California 1906 and Alaska 1964 earthquakes
Authors: Shamsi Sabiha , Stacey Frank D. 
Published: July 2021

Abstract
For eathquakes occurring on fault planes whose horizontal dimensions are very much greater than the vertical dimensions, the assumption of infinite fault length allows the dislocation stress fields to be expressed by simple analytical equations. This facilitates an important generalization of the dislocation theory of earthquakes, in which the fault displacement is graded to zero at the edges of the fault planes, thus avoiding singularities in the stress fields, which are still represented by straightforward analytical expressions. This development is necessary for realistic calculations of seismomagnetic anomalies, due to the piezomagnetic effect in rocks above the Curie point isotherm. The best fit to geodetic observations on the San Francisco earthquake of 1906 is given by a model in which a horizontal slip of 5m at the surface grades either linearly or sinusoidally to zero at (5 ± 1.5) km depth. Vertical displacements of the Alaskan earthquake of 1964 are represented by a compound dislocation having a vertical slip with a maximum value of 40m at 65m depth, graded to zero at 5km and 125km. Maximum total magnetic field anomalies for these models are respectively 2 gammas and 1 gamma per 10−3 e.m.u. of rock magnetization.
Autocorrelation and power spectral density functions of the Parkfield earthquake of June 27, 1966
Authors: Liu Shih-Chi 
Published: July 2021

AbstractThe autocorrelation and power spectral density functions of a total of 14 strong-motion accelerograms of the Parkfield earthquake are obtained. When the ground motions are treated as random phenomena, these functions are found appropriate to be used as statistical characterization functions for the ground motions. Spectral simulation procedure is employed to determine the modal contributions of the motion and the ground characteristic damping and frequency at each station. The results can be used to construct reasonable single- or two-degree-of-freedom linear filters for the generation of a stationary stochastic model for the ground motion. The implications and engineering significance of the basic results are also discussed in some detail.
Earthquake magnitude and source parameters
Authors: Chinnery Michael A. 
Published: July 2021

abstract
Previous attempts to find empirical linear relationships between the magnitude, M, of an earthquake and the logarithm of one or more of the source parameters (length L, width W, displacement D) are reviewed. The fault parameters associated with a set of 27 earthquakes with strike-slip movement in the magnitude range 3.4 to 8.3 are used to test these empirical relationships. It is found that there is no linear relationship between M and log L or log W that is valid over the whole magnitude range. However, a rather good linear relationship is found between M and log D. Using all of the present data, this relationship is
M = 1.32 log ⁡ D + 4.27
If only large magnitude events are used, this becomes
M = 1.04 log ⁡ D + 4.96
Some improvement in determinations of the displacement D for low magnitude events is necessary in order to distinguish between these two formulas. It is surmised that the second may be closer to the truth. The consequences of such a relationship are discussed.
High frequency teleseismic energy from Aleutian sources
Authors: Bufe C. G. , Willis D. E. 
Published: July 2021

abstract
The Long Shot event, detonated at Amchitka in the Aleutian Islands, was recorded at three sites in Michigan at distances of 57 to 63 degrees. Analysis of the data recorded on magnetic tape shows significant high frequency (4-5 Hz) energy in the first compressional wave arrivals at all three stations, although the most prominent spectral peaks are in the range 1.0 to 1.6 Hz. Initial P phases of aftershocks of the Good Friday earthquake of 1964 recorded at the Ann Arbor station do not contain appreciable energy above about 2 Hz. However, the P-wave spectrum of an earthquake of comparable magnitude whose epicenter is near Long Shot is very similar to that of Long Shot, and indicates a favorable signal-to-noise ratio to 5 Hz.
The Long Shot spectra and apparent angle of incidence at the Michigan stations appear to be influenced by the presence of pP and by crustal layering. The effective response of an intermediate-depth well system is shown to be strongly affected by surface reflections.
REPRESENTASI VISUAL PRASI UNTUK MEMPERTAHANKAN KEARIFAN LOKAL MASYARAKAT BALI PADA ERA DISRUPTIF 4.0
Authors: Firmansyah Novian Wahyu , Sutrisno Andika Agung , Pujiyanto Pujiyanto , Herwanto Andhika Putra 
Published: July 2021

Eksistensi merupakan kebutuhan yang mendasar untuk mempertahankan kearifan lokal di era disrupsi 4.0. Masyarakat bali masih mempertahankan berkarya prasi, yakni menorehkan wujud visual pada daun lontar dengan menggunakan penguprak (sebuah pisau kecil). Pendekatan fenomenologi di gunakan untuk mengalokasikan analasis data yang diperoleh. Dalam perkembangan teknologi di era digitalisasi saat ini, eksistesni karya tradisi sangat dipertaruhkan. Bukan menghindar akan tetapi harus beradaptasi, kompromi dengan perkembangan teknologi menjadi strategi. Representasi visual menjadi titik awal dalam melihat keberadaan desain yang muncul pada karya prasi pada era digitalisasi saat ini, wujud desain secara visual membangun persepsi postif dalam mempertahakan seni tradisi menjadi hal esensial dari karya prasi. Digitalisasi menggunakan teknologi manjadi penting mempertahankan eksistensi karya prasi, dikarenakan karya ini dapat diinformasikan secara luas dengan dokumen yang berbentuk digital. Selain itu, diharapkan penelitian ini dapat memberikan inspirasi bagi karya-karya tradisional lainnya dapat bertahan di era disrupsi 4.0 ini dengan memanfaatkan digitalisasi, tidak hanya di Bali, namun juga di daerah-daerah lainnya di Indonesia.
Evaluation of zygomatic bone region for placement of quad zygomatic implants using CBCT in postmenopausal women
Authors: Vaibhav Neelam Manoj , Amirisetty Ramesh , Nichenametla Rajesh , Chandana Gonabhavi Siri , Prathyusha M Santhi , Kumar C Naresh , Reddy B Tanuja 
Published: July 2021

Insufficient height and width of the alveolar ridge at the implant site remains with inadequate bone volume following extraction in older age people especially in postmenopausal women. Postmenopausal women are susceptible to primary osteoporosis where more bone resorption than formation is seen resulting in decreased bone mass. Hence the present study aims to evaluate the zygomatic bone region for placement of quad zygomatic implants using CBCT.: A total of 120 CBCT images of female patients who were between the age group of 45 yrs to 65 yrs were taken. The zygomatic bone was evaluated for pneumatisation zones and thickness of zygomatic bone at three different regions i.e., superior, middle and inferior at nine points on zygoma bone along with bone to implant contact (BIC) region using virtual software. The largest thickness in the superior, middle and inferior regions were at Point A2(8.01+/-2.10 mm), Point B2 (7.01+/-1.62 mm), and Point C1 (6.65+/-1.64 mm), respectively. The virtually placed implants at Point A3 (15.92+/-4.16 mm) and Point B2 (12.02+/-3.62 mm) had the highest BICs. : To obtain the largest BICs, results suggested that the posterosuperior region (Point A3) and the centre of zygoma (Point B1) were the optimal places for the placement of quad zygomatic implants.
Variations in root canal morphology of the permanent mandibular first molar in Indian population- A CBCT study
Authors: Santosh Vasavi , John Rhea Reji , Waghmare Mandavi , Manoj Reema 
Published: July 2021

The purpose of this study was to determine the variations in the number of canals and its morphology in permanent mandibular first molars using cone-beam computed tomography (CBCT) in a subset of Indian population. A total of 350 CBCT scans were collected and evaluated in all three orthogonal planes to determine the number of root canals and study their anatomic variations using Vertucci’s classification.: The total number of roots and root canals, the root canal configuration, the incidence, and the correlations between left- and right-side occurrences and between males and females were analysed. Statistically significant differences were evaluated using the chi-square test with SPSS 16.0 for Windows (SPSS, Chicago, IL), with significance set at p &#60; 0.05.: The results of this study showed that predominantly, two thirds of the subjects had type VI mesial canal configuration and two-thirds had type I distal canal configuration. Also there was significant variance in the canal anatomy across gender and age of the subjects.: CBCT is a clinically useful tool in understanding the variations in root canal morphology, which guides in the assessment of the canal morphology aiding in successful root canal treatment.
Rare case of unilateral hypertrophy of left lamina and spinous process of C6 with associated C2-C3 block vertebra: A case report
Authors: Sharma Monika , Sharma Deepak 
Published: July 2021

We report a rare case of congenital cervical anomaly in a 32 yr old female, who was referred in our department for the complaints of chronic cervical and shoulder pain with a hard cervical mass. Antero-posterior and lateral radiographs of the cervical spine were performed, which show a rib like bony projection, in the left side of neck and on the lateral radiograph, it was corresponding to a hypertrophied C6 spinous process. CT study was done for better delineation of this congenital anomaly, which showed hypertrophied left lamina of C6 and spinous process, crossing midline and towards the left side, extending inferiorly up to the level of thoracic inlet. There was associated fusion of C3 and C4 vertebrae, resulting in block vertebra (Klippel- Feil syndrome Type 1) and unfused spinous process of C6 vertebra.This case report is the first case, where hypertrophied lamina and spinous process of C6 with unfused spinous processes and block vertebra, congenital cervical anomalies were seen in the same patient.
Trans-nasal endoscopic repair without stenting in bilateral congenital bony choanal atresia: Our technique
Authors: Shivnani Deepa , Raman E V , Amle Dnyansh 
Published: July 2021

: Choanal atresia is a commonly observed congenital nasal abnormality. Incidence of choanal atresia is 1 in 7,000 live births. There are various techniques which has been described for the choanal atresia repair. Here we are sharing step by step trans-nasal technique to get good results post-operatively.: The aim of this study to explain and share the technique to treat a bony choanal atresia without any stenting in the nasal cavity of a neonate. The purpose of this study to analyse the surgical outcome of single stage bony choanal atresia repair in terms of restenosis and revision surgery. : We have described the step by step approach for the repair of bony choanal atresia without using any stent in the nasal cavity. Pre surgery evaluation and surgical steps have been explained with photograph to understand this technique better.: Bony choanal atresia can be treated without any stent placement which was the most common method for the repair of congenital choanal atresia in neonates. Clinical significance: This technique will reduce the chances of complication which arises because of stenting in the nasal cavity. This technique is simple and easily reproducible in the practise.
Duchowość liturgiczna – ukryty postulat Vaticanum II
Authors: Sielepin Adelajda 
Published: July 2021

Artykuł dotyczy rzadkiego zagadnienia liturgicznego i teologicznego, które bezpośrednio wskazuje na duchowość, ale jednocześnie w pełni korzysta z realiów liturgii. Nie chodzi bynajmniej o proste połączenie dwu dziedzin nauki i życia Kościoła lub ich metodologiczne pomieszanie, ale o spojrzenie na liturgię przez pryzmat ducha oraz zrozumienie, że duchowość znajduje swoje niezbywalne źródło w liturgii ze względu na obecnego i działającego w niej Chrystusa oraz Jego Misterium odkupienia i uświęcenia. Sygnalizowany w tytule temat to duchowość liturgiczna. W krótkim studium autorka prezentuje aktualne wysiłki podejmujące zagadnienie mistycznego aspektu liturgii, rozpoczynając od postulatów Soboru Watykańskiego II poprzez pokazanie kilku prób definiowania duchowości liturgicznej. W tych nawet kilku lapidarnych określeniach przedmiotu badań odsłania się rola historii z dominującym w poszczególnych okresach rozumieniem duchowości, liturgii oraz Kościoła. Rodzi się zatem potrzeba studiów i formacji przy jednoczesnym docenianiu ukrytych pozornie inspiracji nauki soborowej, które w krótkich sformułowaniach kierują uwagę wiernych na główny profil odnowy.