ARTICLE | doi:10.20944/preprints201806.0466.v1
Subject: Earth Sciences, Geophysics Keywords: Lake Van; Van earthquake; aftershock hypocenters; rupture complexity; azimuthal distribution; aftershock clusters; microseismicity
Online: 28 June 2018 (11:26:31 CEST)
This study presents an analysis of the spatial and temporal distribution of the two large destructive earthquakes that occurred in Lake Van area on October 23, and November 9, 2011, together with the azimuth-dependent distribution of the seismic activity and microseismicity clusters after the mainshocks, associated with the complex rupture processes of their aftershock sequence. The sequence began with the magnitude Mw 7.1 earthquake of 23 October and a second destructive earthquake of Mw 5.6. The aftershock sequences of the two mainshocks were linked to the local crustal faults beneath Lake Van area, followed successively and produced unusually intense activity and significant damage in the area. The main purposes of this study are to document the spatial and temporal distribution and evolution of the October 23, 2011 aftershock hypocenters and the azimuth-dependent distribution of seismic activity, and to understand the spatial and temporal character of the aftershock sequence using the distributional and evolutional patterns of the aftershock hypocenters. A total of 10,000 aftershocks were obtained from seismic data with a high signal-to-noise ratio over collected over three years from October 23, 2011 to March 2014. These aftershocks were plotted for the time periods from November 2011 through March 2012 to March 2014 and ≈ 5000 aftershocks were retained in the depth versus distance cross-sections to detect the clusters in the first step of study (November 2011–March 2012). The focal depth distribution of the aftershock clusters, the migration of hypocenter activity and microseismicity clusters were analyzed and the distributional patterns of the detected clusters were assessed using the geometric distribution of the aftershock hypocenters. The spatial and temporal distribution of aftershocks reveal interesting key features of the deep rupture complexity of the Van earthquake: (1) most prominent aftershocks have been located in the upper crust at depths shallower than 10 km beneath ruptured area, indicating that the upper crust is brittle and seismogenic; (2) two spatial clusters have been detected at 8-10 km depths and the upward extrapolation of these clusters intersects with faults; the main cluster (60 km wide) bounded by inferred reverse faults (f3 and f4) and the central cluster (25–30 km wide) bounded by faults (f1 and f2); (3) these spatial clusters form the largest volumetric pattern of the conical-shaped cluster at depths of about 25–30 km of the azimuth-dependent rotational projections, suggesting azimuthal distributions of deep rupture characteristics; and (4) the strongest temporal cluster of microseismicity derived from temporal distribution of aftershocks has been detected within an area of about 2.5–3.0 km2 and it is spatially observed at 20 km depth within the central cluster, suggesting progressive failure of the adjacent patches of possible fault.
ARTICLE | doi:10.20944/preprints202109.0436.v1
Online: 24 September 2021 (13:00:37 CEST)
Cesarean Section (CS) is one of the most frequently executed surgical procedures in gynecology and obstetrics. After a cesarean section, surgical site infection (SSI) increases hospital stay, lengthens maternal morbidity, and upsurges treatment costs. The current study determines the prevalence and risk factors for surgical site infection following cesarean section in China. A retrospective study was conducted on 23 cases of pregnant women who underwent cesarean section and incision severe infection and detection from March 2017 to January 2020 at Wuhan Maternal and Child Healthcare Hospital in China as the study group, and 20 cases of uninfected cesarean section during the same period were selected as the control group. Data were compared with the controls based on study variables and the presence of SSI. The mean age was 31±2.6. High fever and blood loss were observed in serous SSI-infected patients. The incidence rate of severe surgical site infection was 0.15 %. SSI was observed to be expected in pregnant women who had premature rupture of membrane before surgery (p < 0.001), who underwent postoperative antibiotic therapy (p < 0.001), and the patients who had gestational diabetes mellitus (p <0.001) and hematoma (p < 0.001) during surgery. Hence, following a cesarean section, surgical site infection is common. This research discovered several modifiable risk factors. SSI is associated with multifactorial rather than a single one. The development and strict implementation of a procedure by all health care practitioners can successfully reduce and prevent infection rates following cesarean section.
CASE REPORT | doi:10.20944/preprints202207.0424.v1
Subject: Medicine & Pharmacology, Other Keywords: Traumatic cardiac arrest; gastrothorax; diaphragmatic rupture; diaphragmatic hernia; localized tamponade
Online: 27 July 2022 (15:03:27 CEST)
Traumatic cardiac arrest has a high mortality. We report the case of a 65 years old women who presented a cardiac arrest following traffic accident. Examinations concluded to a tension gastro thorax with a delayed diagnosis. Naso gastric tube insertion was for many authors a temporary care while waiting for surgery. We report on the diagnostic difficulties found in the literature and a recent review of published cases.
ARTICLE | doi:10.20944/preprints202108.0534.v1
Subject: Physical Sciences, Fluids & Plasmas Keywords: surface plasmon resonance; thin film; dropwise condensation; monolayer; dropwise condensation mechanism; nucleation; film rupture theory; degradation of dropwise condensation
Online: 30 August 2021 (10:12:38 CEST)
The objective of this work is to identify the mechanism of dropwise condensation on a smooth solid surface. We investigate the stable dropwise condensation that occurs at a droplet growth rate of 1 µm/s in diameter on a gold-coated glass surface. Additionally, we present our observations on unstable dropwise condensation, i.e., degradation of dropwise condensation of steam on a gold surface. The Surface Plasmon Resonance Imaging (SPRi) approach used in this study has lateral resolutions of 4-10 µm, thickness resolutions of 0.1-1 nm, and temporal resolutions of 200-10,000 frames per second (FPS). SPRi is used to evaluate the existence and structure of thin films and occurrence of initial nuclei during condensation. Visualization of the onset of stable dropwise condensation suggests droplets form at heterogeneous nucleation sites and that no film greater than a monolayer exists on the surface before the formation of droplets. Observation of the unstable dropwise condensation of steam shows the existence of water films that are several nanometers thick between droplets. This work shows that neither the nucleation theory or film rupture theory can individually explain the physics of dropwise condensation. Therefore, there is a need for a more comprehensive theory that can explain the mechanism of dropwise condensation.