bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disinformation under a networked authoritarian state: Saudi trolls’ credibility attacks against Jamal Khashoggi
Authors: Al-Rawi Ahmed 
Published: September 2021

AbstractThis paper deals with a case study that provides unique and original insight into social media credibility attacks against the Saudi journalist and activist, Jamal Khashoggi. To get the data, I searched all the state-run tweets sent by Arab trolls (78,274,588 in total), and I used Cedar, Canada’s supercomputer, to extract all the videos and images associated with references to Khashoggi. In addition, I searched Twitter’s full data archive to cross-examine some of the hashtag campaigns that were launched the day Khashoggi disappeared and afterwards. Finally, I used CrowdTangle to understand whether some of these hashtags were also used on Facebook and Instagram. I present here evidence that just a few hours after Khashoggi’s disappearance in the Saudi Consulate in Istanbul, Saudi trolls started a coordinated disinformation campaign against him to frame him as a terrorist, foreign agent for Qatar and Turkey, liar.... etc. The trolls also emphasized that the whole story of his disappearance and killing is a fabrication or a staged play orchestrated by Turkey and Qatar. The campaign also targeted his fiancée, Hatice Cengiz, alleging she was a spy, while later they cast doubt about her claims. Some of these campaigns were launched a few months after Khashoggi’s death. Theoretically, I argue that state-run disinformation campaigns need to incorporate the dimension of intended effect. In this case study, the goal is to tarnish the reputation and credibility of Khashoggi, even after he died, in an attempt to discredit his claims and political cause, influence different audiences especially the Saudi public, and potentially reduce sympathy towards him.
Low serum levels of bone turnover markers are associated with perirenal fat thickness in patients with type 2 diabetes mellitus
Authors: Jia Xiaoxia , An Yaxin , Xu Yuechao , Yang Yuxian , Liu Chang , Zhao Dong , Ke Jing 
Published: September 2021

Background
Obesity is known as a common risk factor for osteoporosis and type 2 diabetes mellitus (T2DM). Perirenal fat, surrounding the kidneys, has been reported to be unique in anatomy and biological functions. This study aimed to explore the relationship between perirenal fat and bone metabolism in patients with T2DM.

Methods
A total of 234 patients with T2DM were recruited from September 2019 to December 2019 in the cross-sectional study. The biochemical parameters and bone turnover markers (BTMs) were determined in all participants. Perirenal fat thickness (PrFT) was performed by ultrasounds via a duplex Doppler apparatus. Associations between PrFT and bone metabolism index were determined via correlation analysis and regression models.

Results
The PrFT was significantly correlated with β-C-terminal telopeptides of type I collagen (β-CTX) (r = −0.14, P < 0.036), parathyroid hormone (iPTH) (r = −0.18, P ≤ 0.006), and 25 hydroxyvitamin D (25-OH-D) (r = −0.14, P = 0.001). Multivariate analysis confirmed that the association of PrFT and β-CTX (β = −0.136, P = 0.042) was independent of other variables.

Conclusion
This study showed a negative and independent association between PrFT and β-CTX in subjects with T2DM, suggesting a possible role of PrFT in bone metabolism. Follow-up studies and further research are necessary to validate the associations and to elucidate the underlying mechanisms.
Quality evaluation of metal surfaces treatment by wavelet analysis
Authors: Deineha L. , Berezhnoi А. , Kozlov V. , Sudakov V. 
Published: September 2021

Purpose. Analyze the effectiveness of using wavelet analysis to assess the quality of metal surfaces. Investigate the possibility of using wavelet analysis in ultrasonic flaw detection. Determine the optimal wavelet families and their criteria for assessing the quality of metal surface processing.
Research methods. Orthogonal wavelets are considered: Daubechies wavelet, Simlet wavelet and Coiflet wavelet, which provide the possibility of performing a discrete wavelet transform procedure. The criteria influencing the effectiveness of ultrasonic signal filtering by methods using wavelet analysis are considered. Ultrasonic signals were filtered using wavelet functions.
Results. It has been determined that for successful signal filtering, the selected wavelet method must provide a discrete wavelet transformation and have a similarity in the wavelet function shape in the local features of the ultrasonic signals flaw detector. During the work, a rigid threshold for limiting the detail coefficients of wavelet analysis was chosen, as it is the best for filtering tasks. The filtering efficiency is confirmed by the relatively high signal to noise ratio, as well as by the fact that the shape of the pulse extracted from the defect remained almost unchanged.
Scientific novelty. When using the Daubechies and Coiflet wavelets as basic functions, as a result of wavelet filtering, it was possible to increase the signal to noise ratio by 20 dB and confidently isolate the useful signal against the background noise, which indicates the prospects of using this kind of transformations in filtering problems.
Practical value. The obtained solutions can be used for implementation in signal filtering algorithms in digital processing units of automated non-destructive ultrasonic control systems.
Obtaining tube blanks from copper-nickel alloy МНЖ 5-1 when using a tool made of die steel adjustable austenitic transformation during operation
Authors: Sydorchuk O. 
Published: September 2021

Purpose. Production of die tool from steel with regulation of austenitic transformation during operation to increase the level of service life during hot deformation of copper-nickel alloy.
Research methods. Metallographic, high-temperature X-ray phase and dilatometric analyzes of research steel.
Results. The mode of heat treatment (incomplete annealing) of steel 4Х3Н5М3Ф at a temperature of 750±20 °С, obtained by electroslag remelting, allowed to obtain a perlite-sorbitol structure at a hardness of33–34 HRC and allowed better machining by cutting the workpiece alloy. The proposed mode of final heat treatment (hardening 1030±10 °C and tempering 600±5 °C) of the investigated steel, makes it possible to heat the matrix during operation to a temperature of 600 °C.
Scientific novelty. The thermal stability of the tool for hot deformation can be significantly increased when using steel with adjustable austenitic transformation during operation. Such steel in the initial state has a ferrite base, and when heated to operating temperatures occurs from α-Fe to γ-Fe conversion and, subsequently, the austenitic structure is preserved throughout the period of high-temperature operation of the stamping tool. It is confirmed that the stamping tool made of steel 4Kh3N5М3F when pressing a copper-nickel alloy works in the temperature range corresponding to the austenitization process.
Practical value. Abbreviated technological operation, namely thermo-deformation processing (forging) of ingots obtained by electroslag remelting. Experimental-industrial tests of the die tool of steel 4Х3Н5М3Ф in the manufacture of tube blanks of Ø 67±0,1 mm from a copper-nickel alloy of the МНЖ 5-1 brand are carried out. As a result of research “Artemovsk plant for processing of non-ferrous metals and alloys” (Bakhmut, Donetsk region, Ukraine) at an operating temperature of 900–950 ° C, matrices made of steel 4Х3Н5М3Ф (without deformation-forging) showed stability in three times higher than the matrices from steel 3Х3М3Ф made at the enterprise.
Use of additive technologies in the manufacture of central impactors
Authors: Tatarchuk T. , Kravchuk Yu. , Pelykh V. 
Published: September 2021

Purpose. Analysis of methods of manufacturing centrifugal blades by 3D printing methods on the example of a modernized cooling system of the AI-450M engine of the Mi-2MSB helicopter.
Research methods: calculation method of finite elements, analytical.
Results. Studies have shown that the use of layer-by-layer printing technology of the centrifugal wheel of the cooling system provides the following opportunities and improvements:
- reduce the percentage of rejection of finished products by 8–9 times;
- reduce material consumption by 300–400 %;
- increase the speed of production, experiments and testing the manufacture of working elements through the development of new technologies for rapid production (rapid fabrication);
- easy printing of previously “impossible” geometry.
The analysis of possible types of manufacturing of working centrifugal wheel and the calculated estimation of thermodynamic parameters in the course of step-by-step drawing of layers of metal is carried out. The problem of a large percentage of defects in the process of classical-mechanical milling of blades was solved by changing the type of production to additive one.
Scientific novelty. In today's world, the spread of CAD / CAM / CAE / PLM technologies and the accumulation of a wide library of materials open up a large number of new and more efficient, in terms of economy and quality, methods of manufacturing components and units. Following the example of such giants in the production of aircraft engines as Rolls-Royce Motor, General Electric and Pratt & Whitney, it is clear that the use and development of the latest methods of three-dimensional printing is appropriate.
Practical value. The obtained results are important in the further process of production and modernization ofMi-2 helicopter of all modifications with the latest engines, as well as for projects for the development of helicopter construction in Ukraine - МСБ-2 “Hope”, МСБ -6 “Otaman”, МСБ-8 and others. The ability to increase the efficiency of manufacturing the main working elements - blades allows you to reduce the cost of components, their further repair, operation. The most important factor is to increase reliability, as in the manufacture reduces the likelihood of defects, which will not be detected at the stages of intermediate and final control.
Introduction to the Special Issue on GaLA Conf 2020
Authors: Marfisi-Schottman Iza , Hamon Ludovic , Klemke Roland , Laforcade Pierre , Bellotti Francesco 
Published: September 2021

This special issue of the International Journal of Serious Games offers very valuable extensions to the best papers of the 2020 edition of the GaLA conference.
The local organization committee was composed of computer scientists of Laval (France), affiliated to Le Mans Université.
From the 9th to the 10th of December 2020, 500 participants attended to a well-organized conference, through their virtual avatars, and listened to 37 presentations on Serious Games and Gamification. A special session was related to Virtual Reality, in a pedagogical and gaming context.
The four extended papers, published in this journal, significantly extend their original work, and were accepted through a regular peer-review process for this special issue.
Determining the knowledge levels of secondary education students on tuberculosis before and after training
Authors: ETİZ Pınar 
Published: September 2021

Purpose: This study aims to evaluate the results of the training about tuberculosis given to secondary school students and to compare the knowledge levels of the students who received the aforementioned training before and after the training depending on various variables.
Materials and Methods: The universe of this descriptive study consists of 700 students studying in a secondary education institution affiliated with the Ministry of National Education in Adana. The sample, on the other hand, consisted of 600 students who are volunteered to participate in the study. Personal information form and tuberculosis information form are used as data collection tools in the study, and the data are obtained in the 2017-2018 academic year.
Results: While females constitute 57.5% of 600 students participating in the study, males constitute 42.5%. The average age of the students is 16.45±1.08 years. The percentages of the tuberculosis knowledge level of the students before the training vary between 10 and 100 and the average is 59.31±15.61. The percentages of the tuberculosis knowledge level of the students after the training vary between 70 and 100 and the average is 95.30±7.35. The average percentage of tuberculosis knowledge level after training was found statistically significantly higher than that of the pre-training level.
Conclusion: The increases in the correct answer to all questions in the questionnaire after the training compared to the pre-training level were found to be statistically significant.
Composite absorbing boundaries for the numerical simulation of seismic waves
Authors: Dai Nanxun , Vafidis Antonios , Kanasewich Ernest 
Published: September 2021

AbstractComposite absorbing boundary methods are developed for the numerical simulation of seismic waves. These methods combine low-angle absorbing boundary conditions, based on the characteristic analysis of one-dimensional wave equations, with either of two novel wave field modification approaches, namely the anisotropic filters and the one-way sponge filters. The anisotropic filter method adjusts the propagation direction of the waves, so that they reach the boundary at normal angles. The one-way sponge filter method endows the transition zone with a dissipation mechanism that selectively damps the incoming waves. These methods absorb not only the body waves but also the surface waves. A narrow transition zone adjacent to a computational boundary is introduced whose width is smaller than in the sponge filter approach. Numerical examples illustrate the effectiveness of these methods in absorbing the artificial reflections.
Fault-zone waves observed at the southern Joshua Tree earthquake rupture zone
Authors: Hough S. E. , Ben-Zion Y. , Leary P. 
Published: September 2021

Abstract
Waveform and spectral characteristics of several aftershocks of the M 6.1 22 April 1992 Joshua Tree earthquake recorded at stations just north of the Indio Hills in the Coachella Valley can be interpreted in terms of waves propagating within narrow, low-velocity, high-attenuation, vertical zones. Evidence for our interpretation consists of: (1) emergent P arrivals prior to and opposite in polarity to the impulsive direct phase; these arrivals can be modeled as headwaves indicative of a transfault velocity contrast; (2) spectral peaks in the S wave train that can be interpreted as internally reflected, low-velocity fault-zone wave energy; and (3) spatial selectivity of event-station pairs at which these data are observed, suggesting a long, narrow geologic structure. The observed waveforms are modeled using the analytical solution of Ben-Zion and Aki (1990) for a plane-parallel layered fault-zone structure. Synthetic waveform fits to the observed data indicate the presence of NS-trending vertical fault-zone layers characterized by a thickness of 50 to 100 m, a velocity decrease of 10 to 15% relative to the surrounding rock, and a P-wave quality factor in the range 25 to 50.
Effects of crustal structure under the Barents and Kara Seas on short-period regional wave propagation for Novaya Zemlya explosions: Empirical relations
Authors: Zhang Tianrun , Lay Thorne 
Published: September 2021

AbstractShort-period seismic recordings at regional and upper mantle distances from underground explosions at Novaya Zemlya demonstrate that propagation across the continental shelf under the Barents and Kara Seas appears to modify the partitioning of energy between Lg and Sn phases relative to purely continental paths in the Eurasian crust. While the underwater segments of the paths are relatively short, variations in bathymetric characteristics from path to path influence the regional wave field, with systematic behavior that can be used to establish empirical amplitude corrections for regional phases. We analyze a large set of Eurasian recordings to explore the relationship between regional phase energy partitioning and bathymetric characteristics. Maximum water depth along the path is the most influential factor for the Novaya Zemlya data. It has strong linear correlations with the logarithmic rms amplitude of Lg and the ratios Sn/Lg and P/Lg. The maximum water depth probably reflects the extent of necking of the crustal wave guide under the continental margin, which may disrupt Lg modes resulting in Lg to Sn scattering, but there is surprising sensitivity to small variations in bathymetry. Empirical relations like those found here may be useful for nuclear yield estimation and discrimination for regions such as the Korean Peninsula and Persian Gulf, where many seismic phases traverse water-covered continental shelf with poorly known crustal structure.
Calibration of seismometers using ground noise
Authors: Pavlis Gary L. , Vernon Frank L. 
Published: September 2021

Abstract
We have developed and tested a new technique for calibration of seismometers using continuous recordings of ground noise. The method is founded on analytic techniques recently developed for estimation of transfer functions in magnetotellurics. We find that the technique can produce precise, absolute calibration measurements on sensors that do not have calibration coils. The data used are obtained by placing two sets of sensors close enough together that we can assume they record the same ground motion. It is further assumed that one of the sensors has a known, absolute calibration. One then records ground noise of sufficiently high amplitude to guarantee that one is recording above the amplifier noise floor across the entire frequency band of interest. Data are recorded for a time period that depends upon the lowest frequency that is to be resolved. The data is then divided into a series of N partially overlapping time windows, transfer-function estimates are calculated from each of these N time windows, and finally a robust mean estimation procedure is used to produce transfer-function estimates at a set of discrete frequencies. We applied this technique to produce calibration estimates for four different types of sensors (GS-13, triaxial 4.5-Hz L-28, STS-2, and triaxial L4) in various recording arrangements. We found that the technique worked extremely well in every case at frequencies above the point where the sensor output dropped into the instrument noise floor. Problems were consistently encountered above some high-frequency limit that depended upon the site and sensor being tested, and, as a result, we conclude that obtaining reliable results at higher frequencies requires more care in the experimental procedure. We show results from 4.5- and 1-Hz passive sensors plastered onto the same pier, which show nearly perfect coherence out to 100 Hz, and excellent agreement with theoretical predictions between 0.03 and 20 Hz. However, above 20 Hz, a systematic phase error plagues our results. Other cases were comparable when care was taken in the experimental procedure, but differed in detail. We argue that there are fundamental problems recording ground noise at these higher frequencies as a result of the following three experimental problems that can be difficult to control: (1) coupling of sensors to a common, stable platform, (2) contamination by acoustic and pier resonances in typical recording vaults, and (3) resonances of the sensor-pier-ground system.
Qp-Qs relations in the sedimentary basin of the upper Mississippi Embayment using converted phases
Authors: Chen Kou-Cheng , Chiu Jer-Ming , Yang Yung-Tun 
Published: September 2021

AbstractThree-component digital seismograms recorded by the 40 PANDA (Portable Array for Numerical Data Acquisition) stations in the New Madrid seismic zone were analyzed to study seismic wave attenuation in the sedimentary basin using the spectral ratio method. A prominent S-to-P (Sp) converted phase was generated at the boundary between the uppermost sedimentary basin and the underlying Paleozoic rocks. The direct S wave on the horizontal component is characterized by a lower-frequency content than that of the converted Sp wave on the vertical component. The differences in frequency content between the direct S and the Sp converted waves can be attributed to the different attenuation effects between P and S waves in the unconsolidated sediments. The spectral ratio between the low-frequency S wave and the high-frequency converted Sp wave from the bottom of the sediments can be used to yield a relationship between Qp and Qs in the sediments. Results from PANDA stations with well-constrained spectral ratios in the frequency range from 2 to 25 Hz give the Qp value ranging from 25 to 60 and Qs from 25 to 30 for the sedimentary basin in the upper Mississippi Embayment.
Liquefaction during the 1990 Manjil, Iran, earthquake, I: Case history data
Authors: Yegian M. K. , Ghahraman V. G. , Nogole-Sadat M. A. A. , Daraie H. 
Published: September 2021

Abstract
During the 1990 Manjil, Iran, earthquake (MS = 7.7), an estimated 35,000 people lost their lives and more than 300,000 were left homeless. The earthquake ground shaking caused enormous destruction of unreinforced structures. In addition, widespread liquefaction contributed significantly to building damage in towns as far away as 85 km from the ruptured fault. Following the earthquake, the authors surveyed the liquefaction regions, conducted geotechnical field explorations, and documented case histories on liquefaction of level ground, liquefaction-induced building settlement, permanent ground displacement, and performance of piles and piers in liquefied soils. This article presents and discusses the data of the case histories investigated. In addition, based on the evidence from the Manjil earthquake, the importance of geologic input in mapping of liquefaction potential in earthquake-prone regions is demonstrated. In the companion article, the authors present the results of their analyses of liquefaction-related case histories.
Global positioning system resurvey of Southern California Seismic Network stations
Authors: Haase Jennifer S. , Hauksson Egill , Kanamori Hiroo , Mori Jim 
Published: September 2021

Abstract
Systematic errors in travel-time data from local earthquakes can sometimes be traced to inaccuracies in the published seismic station coordinates. This prompted a resurvey of the stations of the Caltech/USGS Southern California Seismic Network (SCSN) using the Global Positioning System (GPS). We surveyed 241 stations of the SCSN using Trimble and Ashtech dual-frequency GPS receivers and calculated positions accurate to 3 m using differential positioning from carrier phase measurements. Twelve percent of the stations that were surveyed were found to be mislocated by more than 500 m. Stations of the TERRAscope and USC networks were also surveyed, as well as a network of portable seismic stations deployed shortly after the 1992 Joshua Tree and Landers earthquakes. The new coordinates and the offsets from the old coordinates are given below. The new coordinates are being used in SCSN locations as of 1 January 1994.