In its Sixth Edition, this book has been updated and revised to incorporate new information on technology, economic, and political issues that have impacted the use of fluids to drill and complete ...oil and gas wells. With updated content on completion fluids and reservoir drilling fluids; health, safety and environment; drilling fluid systems and products; new fluid systems and additives from both chemical and engineering perspectives; wellbore stability, adding the new R&D on water-based muds; and equipment and procedures for evaluating drilling fluid performance in light of the advent of digital technology and better manufacturing techniques, this book has been thoroughly updated to meet the drilling and completion engineer's needs.
The CAMS New Zealand meteor shower survey detected a brief outburst of delta Pavonids (IAU shower 120, code DPA) with a compact radiant on March 31, 2019. This is the first instrumental detection of ...a shower long suspected to exist by visual observers monitoring the theoretical radiant of parent comet C/1907 G1 (Grigg-Mellish), despite it being listed in comet catalogs only with a parabolic orbit. The 2019 detection of an associated meteor shower confirms that this comet moves in an elliptical orbit. The range of allowed orbit solutions fitted to the 1907 observations of the comet strongly correlate node and semi-major axis. Taking into account the difference in node between comet orbit and dust trail, the time of the outburst constrains the comet orbital period to 447 ± 80 years (heliocentric), having last been near the sun in A. D. 1460 ± 80 years. The corresponding elliptical orbital elements for C/1907 G1 are presented. The short 23-min duration of the outburst (FWHM = 16 min) confirms that C/1907 G1 is a small comet, having ejected dust with low ejection speeds. It passed close enough to Earth orbit to be a potentially hazardous comet in future returns.
•An outburst of meteors on March 31, 2019, shows that parent comet Grigg-Mellish moves in an elliptical orbit and was near the Sun before.•The timing of the outburst, combined with the observations of the comet in 1907, constrains the comet orbital period.•The timing of the outburst, combined with the observations of the comet in 1907, constrains the comet orbital period.•The comet ejected the meteoroids when it was near the Sun in A. D. 1460 ± 80 y.•Because the comet will return, and has a small miss-distance, it is a potential impact hazard to Earth.
In the present study, we used an integrative taxonomy approach to redescribe a population of Echiniscus quadrispinosus quadrispinosus Richters, 1902 from the neotype locality in the Taunus Mountain ...Range (Germany). We found clear differences in the chaetotaxy formula between the life stages of E. q. quadrispinosus. The body appendages B are, in general, absent in juveniles. Moreover, in larvae all body lateral appendages, except for E, are absent. We also obtained DNA sequences of 18S rRNA, 28S rRNA, ITS-2, and COI of E. q. quadrispinosus from the neotype locality and three Norwegian populations. Comparison with the sequences available in GenBank showed low genetic differences between the neotypic population and specimens from other localities. Therefore, we decided to establish our specimens from Taunus Mountain Range as neotype and paraneotypes of E. q. quadrispinosus. We also discussed and amended the taxonomic status of three subspecies E. q. brachyspinosus Bartoš, 1934, E. q. cribrosus Murray, 1907 and E. q. fissispinosus Murray, 1907 and established them as junior synonyms of E. q. quadrispinosus. Finally, we also confirmed E. lichenorum Maucci, 1983 as a valid species, clearly different from E. q. quadrispinosus.
ABSTRACT
We report X-ray observations of the high mass X-ray binary (HMXB) pulsar 4U 1907+09. Spectral and timing analysis of the source has been performed using Nuclear Spectroscopic Telescope Array ...(NuSTAR) observation. Timing analysis of the photon events revealed the coherent X-ray pulsation of the source with a pulse period of 442.92 ± 0.03 s. It is observed that the source is spinning down at a rate of 0.1971(4) s yr−1. The pulse profile is characterized by a decaying amplitude of the secondary peak and relative growth in the amplitude of the primary peak with an increase in energy. The broad-band spectral coverage of NuSTAR has been used to observe multiple absorption features in the X-ray continuum of the source. We confirm the presence of two prominent cyclotron absorption features at ∼17 and ∼38 keV, respectively. In addition, we have detected an absorption-line feature at ∼8 keV, with an equivalent width of ∼1.3 keV. The variation of the spectral parameters with pulse phase has been observed using phase-resolved spectroscopy and the relevant variabilities of the parameters have been discussed with the underlying physical implications. The continuum evolution and variations in spectral parameters have also been studied by time-resolved spectroscopy.
По материалам с Камчатки указывается Oxytelus (Tanycraerus) jessoensis Bernhauer, 1907. Проиллюстрирован хабитус, эдеагус и VIII стернит самца. Приводятся и проиллюстрированы отличия O. jessoensis от ...близких видов: Oxytelus (Tanycraerus) laqueatus (Marsham, 1802); Oxytelus (Tanycraerus) assingi Schülke, 2012 and Oxytelus (Tanycraerus) ruthenus Semionenkov & Gildenkov, 2022. Oxytelus jessoensis отличается от O. assingi более светлой окраской основания антенн (1–4 членики) и ротовых органов. Вид хорошо отличается от O. assingi и O. ruthenus строением VIII стернита брюшка самца и парамер эдеагуса.
On 4 January 1907, an earthquake occurred off the west coast of Sumatra, Indonesia, with an instrumental surface-wave magnitude (
M
S
) in the range of 7.5–8.0 at periods of ~ 40 s. The tsunami it ...generated was destructive on the islands of Nias and Simeulue, where it killed hundreds and gave rise to the legend of the S’mong. This tsunami was also observed in other parts of the Indian Ocean basin. Relative to its instrumented magnitude, the size of the tsunami was anomalous, qualifying the event as a “tsunami earthquake”. However, unusually for a tsunami earthquake, the shaking on Nias was severe (7 EMS). We revisit the 1907 earthquake with a multidisciplinary approach by extracting evidence describing shaking effects or the tsunami from written documents and by acquiring new seismograms. Combining these, we discriminate two large earthquakes within an hour of each other with clear differences in seismological character. The first we interpret to be a tsunami earthquake with characteristic low levels of shaking, an estimated average seismic moment (
M
0
) of 2.5 × 10
28
dyn cm (
M
W
≈ 8.2) in the frequency band 6–8 mHz, and an epicentral location close to the front of the Sunda Megathrust. The seismograms we analyzed also document a regular growth of moment with period, approaching
M
W
≈ 8.4 at the longest resolvable period (~ 170 s). For the second earthquake that caused damage on Nias, we estimate
M
S
≈ 7 based on seismograms and phase data. We also identify two
M
S
≈ 6 aftershocks within 24 h of the mainshock. Additionally, we present a dataset of 88 locations within the Indian Ocean basin where the tsunami was observed. Using a subset of these, we forward modeled the tsunami to propose a seismic rupture model extending along the Sunda Megathrust for about 220 km (~ 94.7°E to ~ 97°E) with a maximum modeled slip of ~ 21 m. Our new rupture model provides an acceptable fit to our new dataset of tsunami runup and inundation values from 88 local and far-field locations in the Indian Ocean basin. We also urge caution against an over-reliance on the S’mong legend for tsunami evacuation as its premise, that a tsunami will only follow an earthquake with very severe ground motions, is rendered ineffective for tsunami earthquakes.
Representatives of the younger generation have always - been active participants in revolutionary events in Ukraine both during the rule of the Russian Empire and during the period of Ukraine’s ...independence. Ego-documents are documents that contain important details that characterize the activity, motivation, and characteristics of young people’s activities: letters, diary entries, and memories. By comparing their content with the descriptions of important events of 1905-1907, it is possible to determine the peculiarities of the participation of young people in attempts to organize the population of certain regions for struggle, as was the case in the city of Lubny in the Poltava region. Written materials related to Anastasia Grinchenko’s and Maria Livytska’s public activities demonstrate the embodiment of revolutionary ideas in behavioral practices of the young generation of political figures of the Naddnipryanshchyna region.
Western part of Zagreb is delineated by the Street of the Republic of Austria on the east side, Ilica Street in the north, the railway line in the south and the Črnomerec stream in the west. It was ...enclosed into a masterplan for the first time in the Regulatory Plan from 1887 and envisaged as the extension of the Lower Town to the west. In the first Regulatory Plan of Zagreb from 1865, only the square in front of the railway station was located there, while the rest was not encompassed. Since the opening of the first railway station in 1862, industrial plants have been randomly built into the western part of the city. In 1878 the City Waterworks were put into operation and at that occasion the first Waterworks Road (Vodovodna cesta) was staked out, connecting Ilica, the historical roadway in the north (since the 15th century), with the City Waterworks. In Milan Lenuci’s Regulatory Plan from 1907 the western part of the city retained its layout. The only urban planning since the end of the 19th century until the First World War in the western part of Zagreb was implemented with the aim of connecting six army barrack complexes.
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