Single Detachment Research Articles

Use of Vertical Greenery Systems for the domestic scale treatment of greywaters for fit-for-purpose reuse. Applicability and future prospects.

Abstract Only less than 1% of the Earth’s water is fit for human activities. Domestic consumption accounts for roughly 20% of all uses of water, adding pressure to the increasing water scarcity stress. Water intakes of residential buildings for all everyday uses are constituted by a high-quality resource, which is either costly to produce or conspicuous in amounts to withdraw from natural sources. The present proposal aims to test the feasibility of the application of decentralized greywater treatment strategies, based on the use of vertical greenery systems integrated into residential buildings to assess both the optimal scale of application in residential settlements and a comparative analysis on reclaimed water resource savings. The aim is to promote the circular use of water resources by allowing for fit-for-purpose employment, thus reducing the overall intake due to the residential sector. The methodology hereby proposed has been developed using as a case study the most widespread residential typologies in the Southern Italian context, such as single detachment, row houses, low and medium-rise apartment buildings. The result is the proposition for each residential typology of a retrofitting strategy that employs the integration of a green infrastructure inside the residential spaces. Until now, the Mediterranean context has been characterized by limited use of strategies directed towards the efficient employment of water resources, since the mild climatic conditions have always provided for an adequate amount of freshwater. Therefore, limited studies have been carried out on the application of those strategies in Mediterranean landscapes. However, the rapid shift in precipitation patterns due to climate change has defined the need to quickly embrace new strategies, systems, and technical solutions for improving water use efficiency and promoting reuse.

Low ice adhesion on soft surfaces: Elasticity or lubrication effects?

HypothesisSoft materials are promising candidates for designing passive de-icing systems. It is unclear whether low adhesion on soft surfaces is due to elasticity or lubrication, and how these properties affect the ice detachment mechanism. This study presents a systematic analysis of ice adhesion on soft materials with different lubricant content to better understand the underpinning interaction. ExperimentsThe wetting and mechanical properties of soft polydimethylsiloxane with different lubricant content were thoroughly characterized by contact angle, AFM indentation, and rheology measurements. The collected information was used to understand the relationship with the ice adhesion results, obtained by using different ice block sizes. FindingsThree different de-icing mechanisms were identified: (i) single detachment occurs when small ice blocks are considered, and the ice completely detaches in a single event. In the case of larger ice blocks, the reattachment of the ice block is promoted by either: (ii) stick–slip or, (iii) interfacial slippage, depending on the lubricant content.It was confirmed that the ice adhesion strength not only depends on material properties but also on experimental conditions, such as the ice dimensions. Moreover, differently than on hard surfaces, where wetting primarily determines the icephobic performance, also elasticity and lubrication should be considered on soft surfaces.

Withdrawn: Low ice adhesion on soft surfaces: Elasticity or lubrication effects?

HypothesisSoft materials are promising candidates for designing passive de-icing systems. It is unclear whether low adhesion on soft surfaces is due to elasticity or lubrication, and how these properties affect the ice detachment mechanism. This study presents a systematic analysis of ice adhesion on soft materials with different lubricant content to better understand the underpinning interaction. ExperimentsThe wetting and mechanical properties of soft polydimethylsiloxane with different lubricant content were thoroughly characterized by contact angle, indentation, and rheology measurements. The collected information was used to understand the relationship with the ice adhesion results, obtained by using different ice block sizes. FindingsThree different de-icing mechanisms were identified: (i) single detachment occurs when small ice blocks are considered, and the ice completely detaches in a single event. In the case of larger ice blocks, the reattachment of the ice block is promoted by either: (ii) stick–slip or, (iii) interfacial slippage, depending on the lubricant content.It was confirmed that the ice adhesion strength is not a material property, since it depends on the ice block size. As such, differently than on hard surfaces, where wetting primarily determines the icephobic performance, also elasticity and lubrication need to be considered on soft surfaces.

The promising impact of Bemcentinib and Repotrectinib on sleep impairment in Alzheimer’s disease

Alzheimer’s disease (AD), the most prevalent neurodegenerative disease, demands effective medication to alleviate symptoms. This study focused on sleep impairment as an overt clinical symptom and tauopathy as a prominent molecular symptom of this disease. Multiple compounds from three biomolecule libraries (719 compounds; ChemDiv:366 – ChEMBL:180 – PubChem:173) were evaluated for potential binding affinity and safety using AutoDock Vina and pkCSM, respectively, resulting in the selection of four candidate compounds (Lestaurtinib, Repotrectinib, Bemcentinib, and Zotiraciclib). Due to the similarity of Repotrectinib and Bemcentinib binding sites to ATP, 300 ns Martini 3 coarse-grained molecular dynamics (MD) was performed on these two molecules and ATP by NAMD. The stability of tau protein in the presence of drugs was assessed using a 200 ns Martini 3 MD simulation. Binding site analysis discloses Bemcentinib and Repotrectinib as two inhibitors occupying most amino acids in binding with ATP. The RMSD and RMS average correlation results revealed protein containing Bemcentinib and Repotrectinib to have a more stable state compared to ATP in the first 220 ns simulation. There was only a single detachment of Bemcentinib, while Repotrictinib detached twice at the end of the simulation. Eventually, adding Bemcentinib and Repotrectinib to the enzyme-tau complex significantly increased the number of tau detachments during the 200 ns simulation. We report Bemcentinib and Repotrectinib, formerly prescribed for cancer, as potential inhibitors of the CK1 δ. Besides their high binding affinity compared to ATP, they can inhibit all ATP-binding sites and alter the tau binding stability. Communicated by Ramaswamy H. Sarma

Forced Subduction Initiation Near Spreading Centers: Effects of Brittle‐Ductile Damage

AbstractAlthough positive buoyancy of young lithosphere near spreading centers does not favor spontaneous subduction, subduction initiation occurs easily near ridges due to their intrinsic rheological weakness when plate motion reverses from extension to compression. It has also been repeatedly proposed that inherited detachment faults may directly control the nucleation of new subduction zones near ridges subjected to forced compression. However, recent 3D numerical experiments suggested that direct inversion of a single detachment fault does not occur. Here we further investigate this controversy numerically by focusing on the influence of brittle‐ductile damage on the dynamics of near‐ridge subduction initiation. We self‐consistently model the inversion of tectonic patterns formed during oceanic spreading using 3D high‐resolution thermomechanical numerical models with strain weakening of faults and grain size evolution. Numerical results show that forced compression predominantly reactivates and rotates inherited extensional faults, shortening and thickening the weakest near‐ridge region of the oceanic lithosphere, thereby producing ridge swellings. As a result, a new megathrust zone is developed, which accommodates further shortening and subduction initiation. Furthermore, brittle/plastic strain weakening has a key impact on the collapse of the thickened ridge and the onset of near‐ridge subduction initiation. In contrast, grain size evolution of the mantle only slightly enhances the localization of shear zones at the brittle‐ductile transition and thus plays a subordinate role. Compared to the geological record, our numerical results provide new helpful insights into possible physical controls and dynamics of natural near‐ridge subduction initiation processes recorded by the Mirdita ophiolite of Albania.

Structural characteristics and mechanism of the Hengshui accommodation zone in the southern Jizhong subbasin, Bohai Bay basin, China

Based on seismic data, we document the differences in the geological structure and evolution on the two sides of the Hengshui Accommodation Zone (HAZ), identify the timing of faulting on faults, and analyze the mechanism of the HAZ. The northern part of the HAZ is characterized by a half-graben controlled by double detachment faults with opposite dips, and the southern part of the HAZ is characterized by a compound half-graben controlled by a single detachment fault with multiple faults. The structural evolution of the southern Jizhong subbasin can be divided into the following five stages: the basement evolution stage; Rift Episode I (Ek-Es4); Rift Episode II (Es3–Es2); Rift Episode III (Es1-Ed); and the Postrift stage (Nm-Ng). Three segments were identified along the HAZ, namely, the Xinle Anticline (XLA), the Ningjin Segment (NJS) and the Hengshui Transfer Fault (HSTF). The XLA is a transverse anticline produced by the fault section of the Taihang Mountain Piedmont Fault (TMPF). The NJS is a transfer fault formed by the differential extension of the Ningjin Fault. As a major part of the HAZ, there are obvious differences in the faults on both sides of the HSTF, and NE-trending Cenozoic faults were mainly on its north side, while the NNE-trending faults formed in the basement stage were distributed on its south side. During the basement evolution stage, NNE-trending basement faults and the HSTF developed by WNW extension. During Rift Episode Ⅰ (Ek-Es4), under the NW extension, NE-trending fault segments formed, and pre-existing faults were reactivated. During Rift Episode Ⅱ (Es3–Es2), pre-existing faults were subjected to oblique extension, and the NE-trending fault segments on both sides of the HSTF grew into the main fault and intersected with the HSTF. From Rift Episode III (Es1-Ed) to the present, some pre-existing faults have been reactivated, and many new secondary faults in the basin have finally produced the present structural pattern. These results suggest that the continuous transfer of the regional stress field during the Mesozoic and Cenozoic was the driving force for the formation and evolution of the HAZ.

Abstract 11144: Mitral Valve Leaflet Strains Are Unphysiologically Altered After Mitraclip to Repair Functional Mitral Regurgitation

Introduction: Transcatheter edge-to-edge repair (TEER) by approximating the leaflet edges with the MitraClip system ( Fig. A ) is rapidly gaining momentum as the primary therapy for repair of functional mitral regurgitation. Though effective acutely, the unphysiological mechanics that TEER imposes on the valve can be substantial and effect durability of the repair. In this study, we used stereo digital image correlation (sDIC) to quantify the leaflet strains that TEER imposes on the mitral valve in the repair of FMR. Hypothesis: TEER imposes an unphysiological diastolic and early systolic strain on the mitral valve leaflets, which may be associated with poor long-term outcomes. Methods: MVs with intact papillary muscles (PMs) were isolated from porcine hearts and mounted within an acrylic left ventricle chamber. A speckle pattern was imprinted on the valve leaflet surface and a sDIC system with two high-speed cameras imaging at 250 fps recorded synchronized image sequences upon pressurization of the chamber to 120 mm Hg in three different configurations: baseline/healthy, FMR/tethered valve configuration, and with TEER/MitraClip. Results: FMR configuration ( Fig. A2 ) did not alter the peak systolic leaflet strains but elevated the diastolic leaflet strains. The time to peak strain was delayed as well in the FMR configuration. TEER reduced the overall systolic strains on the leaflet from the disease state, but the diastolic strains were further elevated compared to FMR condition. Sub-regional analysis depicted that the leaflet edge section where the TEER was applied was under constantly high strain throughout the cardiac cycle, without an unloading phase. Conclusions: TEER imposes a supraphysiological strain field on the mitral valve leaflet when used to repair FMR. The impact of such strains is not yet known, but may be associated with leaflet remodeling and the 2% of the procedures in which single leaflet detachment has been reported.

Preparation of a visible light-responsive gold nanoparticle-containing collagen gel microarray for in situ cell separation

Gold nanoparticle (AuNP)-embedded collagen gels have been prepared as a visible light-responsive cell scaffold that is applied to a visible light-induced in situ single cell detachment system. In this study, the visible light-responsive cell scaffold is combined with microarray technology for high-throughput cell separation. The AuNP-embedded collagen gel microarrays were prepared by pressing microarrays with 200 μm pores into the AuNP-embedded collagen gel. The microsized AuNP-embedded collagen gel was downsized to one thousandth of the conventional gel produced in a 96-well plate. Efficient thermal deformation of the microsized collagen gel was exhibited after laser irradiation for several seconds, which suggested that the microsized collagen gels had high sensitivity to the photothermogenic property. A collagen gel microarray with an AuNP coating at the bottom was also prepared; this exhibited morphological change after a shorter laser irradiation period than the AuNP-embedded collagen gel microarray. The cells cultured on the AuNP-embedded collagen gels were dead after laser irradiation but still alive on the collagen gel with the AuNP coating at the bottom. Thus, the AuNP-coated collagen gel microarray might work as a cell-friendly visible light-induced in situ single cell detachment system.

Seismological Investigations in the Olduvai Basin and Ngorongoro Volcanic Highlands (Western Flank of the North Tanzanian Divergence)

AbstractWe present data and results of a passive seismic experiment that we operated between June 2016 and May 2018 in the Ngorongoro Conservation Area (northern Tanzania), located on the western side of the eastern branch of the Eastern African Rift (EAR) system. The motivation for this experiment is twofold: (1) investigating the extension of the Olduvai basin, referred to also as the “Cradle of Human Mankind,” as it hosted a variety of paleoenvironments exploited by hominins during their evolution; and (2) studying the link between the fault system in the main EAR and in its western flank. We conduct detailed data-quality analysis of the seismic recordings based upon ambient noise characterization and numerical waveform simulations. Our data set is of good quality, and we observe that local magnitude can be overestimated up to at least 0.23, due to wave-amplifications effects occurring at sites with loose sedimentary material. Based on a new but simple approach using power spectral density measurements, we calculate the thickness of sedimentary basins. This allows us to map the bottom of the Olduvai paleolake confirming that its sedimentary record may be at least 200 m deeper than previously inferred from core drilling. We also map the bottom of the Olbalbal depression for the first time. In addition, we present a seismicity map of the Ngorongoro Conservation Area with unprecedented detail. The seismicity depicts the suture zone between the Tanzanian craton and the Mozambique belt and reveals that the fault system in the western flank of the rift merges at depth into a single detachment that joins the Manyara fault on the western side of the main rift valley.

Changing the Electronic Polarizability of Monolayer MoS2 by Perylene‐Based Seeding Promoters

AbstractLarge area molybdenum disulfide (MoS2) monolayers are typically obtained by using perylene‐3,4,9,10‐tetracarboxylic acid tetrapotassium salt (PTAS) as organic seeding promoter in chemical vapor deposition (CVD). However, the influence of the seeding promoter and the involvement of the functional groups attached to the seed molecules on the physical properties of the MoS2 monolayer are rarely taken into account. Here, it is shown that MoS2 monolayers exhibit remarkable differences in terms of the electronic polarizability by using two representative cases of seeding promoter, namely, the commercial PTAS and a home‐made perylene‐based molecule, N,N‐bis‐(5‐guanidil‐1‐pentanoic acid)‐perylene‐3,4,9,10‐tetracarboxylic acid diimide (PTARG). By thermogravimetric analysis, it is verified that the thermal degradation of the promoters occurs differently at the CVD working condition: with a single detachment of the functional groups for PTAS and with multiple thermal events for PTARG. As a consequence, the promoter‐dependent electronic polarizability, derived by free charges trapped in the monolayer, impacts on the photoluminescence emission, as well as on the electrical performances of the monolayer channel in back‐gated field‐effect transistors. These findings suggest that the modification of the electronic polarizability, by varying the molecular promoter in a pre‐growth stage, is a path to engineer the MoS2 opto‐electronic properties.

Flow boiling heat transfer characteristics using the modified eulerian and wall heat balance model

Flow boiling heat transfer is routinely encountered in nuclear reactors, steam engines and other engineering applications. Although several researchers have carried out different numerical and experimental investigations on flow boiling, the underlying physics of the interfacial interaction is still a complex phenomenon to understand in detail. Hence, the numerical simulation and optimisation regarding the adoption of engineering flow boiling parameters have been conducted in this study using the Modified Eulerian-Eulerian Model (MEEM) and Wall Heat Balance Model (WHBM). To predict interpenetrating flow fields and to provide detailed relevant information on the flow behaviour, this study considered a uniform axial heating profile for a cylindrical flow channel. The Raynolds Average Navier Stokes (RANS) equation with an appropriate turbulence model are used to predict the effect of turbulence on the mean flow field, while the MEEM multiphase sub-models are employed to predict the temperature distribution along the wall, the average void fraction, tracking of the single bubble detachment diameter, heat balance at the wall, effect of surface roughness on heat transfer, the effect of aspect ratio, and the critical heat flux. The results obtained from this study are compared with the selected numerical investigation and experimental data presented in the open literature. The present study shows a better approximate prediction (with minimal uncertainties) of both the subcooled boiling heat transfer and the saturated boiling heat transfer. In summary, this study agrees with extant theories and experimental predictions. Thus, it has provided more profound insights into flow boiling heat transfer particularly for flow in a vertical pipe.

Tectonics of the Neuch\xe2tel Jura Mountains: insights from mapping and forward modelling

This study focuses on a geological section in the Jura Mountains across the villages of Travers, La Brévine in Switzerland, and Morteau in France. Field mapping was conducted to complement and densify existing data. A kinematically and geometrically consistent forward model has been developed to understand and interpret the observed surface structures. The proposed solution features a low-angle thrust fault with a multiple ramp-flat or staircase trajectory on which several hinterland-verging thrusts nucleate. The main décollement level is located in the Triassic evaporites of the Keuper and Muschelkalk Groups. Our model implies secondary detachments in the Opalinus Clay and the Cretaceous layers leading to repetitions in the Mesozoic cover rocks over large distances. This in turn explains the high topographic position of exposed sediments. The proposed solution is an alternative to models showing overthickening of Triassic evaporites associated with a single detachment level. Along the investigated profile, the Jura Mountains accommodate a shortening of 8.5 km. The kinematic forward model suggests an oscillating sequence of thrusting, rather than a simple, in sequence, forward propagation succession of thrusts.

LATE MITRACLIP SINGLE LEAFLET DETACHMENT: THIRD CLIP IS A CHARM

Single leaflet detachment (SLD) of the MitraClip device occurs in 5% of patients. It is a cause of recurrent mitral regurgitation (MR), usually within the first 30 days after implantation. 60-year-old male with remote coronary artery bypass surgery and severe MR status post 2 MitraClips at A2/P2

On the formation of oceanic detachment faults and their influence on intra-oceanic subduction initiation: 3D thermomechanical modeling

Extensional detachment faults, which have been widely documented in slow-spreading and ultraslow-spreading ridges on Earth, can effectively localize deformation due to their weakness. After the onset of oceanic closure, these weak oceanic detachments may directly control the nucleation of a subduction zone parallel to the former mid-ocean ridge, as is suggested for the Neotethys in Middle Jurassic times. So far, this hypothesis has only been tested by 2D numerical models, whereas the geometry of detachment faults is intrinsically three-dimensional. Here, we conducted a series of 3D numerical thermomechanical experiments in order to investigate the formation of detachment faults in slow oceanic spreading systems and their subsequent response upon inversion from oceanic spreading to convergence.Numerical results show that during the oceanic spreading stage, the formation of detachment faults strongly depends on the magnitude of the healing rate of faulted rocks in the oceanic lithosphere, that reflects the stability of hydrated minerals along fractured rocks. The detachment faults formed in our 3D numerical models deviate from the “rolling hinge model” of oceanic detachment faulting where fault footwalls are rotated and oceanic core complexes are thereby formed. Our results accentuate that the controlling physical parameters for the development of oceanic core complexes and detachment faults can differ, and that their coupled development in nature remains a key target for future research.Upon modeled transition to compression, previously formed asymmetric spreading patterns are prone to asymmetric inversion, where one oceanic plate thrusts under the other. Our results suggest that detachment faults accommodate significant amounts of shortening during the initiation of oceanic closure, but, in contrast to the previously proposed simple conceptual model, no direct inversion of a single detachment fault into an incipient subduction zone is observed. Instead, a widespread interaction of multiple detachment faults occurs after the onset of convergence. Ultimately, the nascent subduction zone cuts through the base of several pre-existing detachment faults, thereby forming an initial accretionary wedge in the incipient fore-arc.

Calculating detachment depth and dip angle in sedimentary wedges using the area–depth graph

Abstract: We apply the area–depth–strain method (ADS) to predict the depth and the dip angle for an underlying bedding-parallel detachment in sedimentary wedge structures with stratigraphic wedge strata using an area–depth graph. An area–depth relationship is proposed and simplified to a linear relationship with depth as a function of excess area. This proposed ADS method gives the depth and dip angle of the detachment at any location in sedimentary wedges. The method does not yield the shortening magnitude from the area-depth graph because the area-depth relationship is different for this structural example from the established methods. We test the method by predicting the detachment depth and dip angle of two natural wedge structures that are well constrained: the Niger Delta fold-and-thrust belt, which has a single detachment, and the Cascadia detachment fold, which has multiple detachments. The predicted geometric values are generally consistent with the geometric characteristics of the two systems. The ADS method is a powerful method for constructing subsurface structural geometries using well constrained near-surface geometry for decollement sedimentary wedges, and is independent of bed-length, bed-thickness and regional horizon throws.

Cup detachment during vacuum-assisted vaginal delivery and birth outcome.

To determine the perinatal outcome associated with cup detachment during vacuum-assisted vaginal delivery (VAVD). A retrospective cohort study of all women attempting VAVD in a tertiary hospital (2012-2014). Singleton-term pregnancies were included. Antepartum fetal death and major fetal structural or chromosomal abnormalities were excluded. Primary outcome was neonatal birth trauma (subgaleal hematoma, subarachnoid hematoma, subdural hematoma, skull fracture, and/or erb's palsy). Secondary outcomes were maternal complications or other neonatal morbidities. Outcomes were compared between women after ≥1 cup detachment (study group) and the rest (control group). Logistic regression analysis was utilized to adjust results to potential confounders. Overall, 1779 women attempted VAVD during study period. Of them, in 146 (8.2%), the cup detached prior to delivery; 130/146 (89%) had a single detachment. After detachment, 4 (2.7%) delivered by cesarean section, 77 (52.7%) delivered after cup reapplication, and 65 (44.6%) delivered spontaneously. Women in the study group were more likely to undergo VAVD due to prolonged second stage, and were characterized by lower rates of metal cup use. Neonates in the detachment group had higher rates of subarachnoid hematoma and composite neonatal birth trauma (2.7 vs. 0.1% and 4.8 vs. 1.8%, respectively, p<0.05). This remained significant after adjustment to potential confounders (subarachnoid hematoma aOR=45.44, 95% CI 6.42-321.62 and neonatal birth trauma aOR=2.62, 95% CI 1.1-6.22, p<0.05 for all). Other neonatal and maternal morbidities were similar between groups. Cup detachment is associated with a higher rate of adverse neonatal outcome. Cup reapplication should be considered carefully.

Extracellular protonation modulates cell-cell interaction mechanics and tissue invasion in human melanoma cells

Detachment of cells from the primary tumour precedes metastatic progression by facilitating cell release into the tissue. Solid tumours exhibit altered pH homeostasis with extracellular acidification. In human melanoma, the Na+/H+ exchanger NHE1 is an important modifier of the tumour nanoenvironment. Here we tested the modulation of cell-cell-adhesion by extracellular pH and NHE1. MV3 tumour spheroids embedded in a collagen matrix unravelled the efficacy of cell-cell contact loosening and 3D emigration into an environment mimicking physiological confinement. Adhesive interaction strength between individual MV3 cells was quantified using atomic force microscopy and validated by multicellular aggregation assays. Extracellular acidification from pHe7.4 to 6.4 decreases cell migration and invasion but increases single cell detachment from the spheroids. Acidification and NHE1 overexpression both reduce cell-cell adhesion strength, indicated by reduced maximum pulling forces and adhesion energies. Multicellular aggregation and spheroid formation are strongly impaired under acidification or NHE1 overexpression. We show a clear dependence of melanoma cell-cell adhesion on pHe and NHE1 as a modulator. These effects are opposite to cell-matrix interactions that are strengthened by protons extruded via NHE1. We conclude that these opposite effects of NHE1 act synergistically during the metastatic cascade.

Deriving Erodibility Parameters of a Mechanistic Detachment Model for Gravels

<abstract> <b><sc>Abstract.</sc></b> Recent research has proposed the use of a mechanistic detachment model, called the Wilson model, in place of the excess shear stress equation for predicting the detachment of cohesive soils during erosion. However, this mechanistic detachment model was also proposed as being valid for noncohesive soils but with limited evaluation. Such erodibility parameters are often needed in erosion models developed using a single detachment rate approach for both cohesive and noncohesive soils. Therefore, the objectives of this research were to evaluate the applicability of the Wilson model for noncohesive soils and to evaluate a procedure for deriving the erodibility parameters (b₀ and b₁) from flume experiments. Gravel samples were extracted from composite streambanks on the Barren Fork Creek in eastern Oklahoma. The samples were sieved into particle size classes, and then at least triplicate flume experiments were performed (gravel sizes of 0.45, 0.60, 1.30, and 1.90 cm). Flow rate, water surface elevation, and scour depth were measured to estimate the energy slope, scour rate, and effective shear stress. The Wilson model was fit to the scour depth data to derive b₀ and b₁ using the generalized reduced gradient method to minimize the error between the predicted and measured scour. Constraints were required within the solver routine to limit potential solutions of b₁. Similar to cohesive soils, b₀ and b₁ had similar relationships to but different magnitudes than the erodibility coefficient (k_d) and critical shear stress (τ_c) for these gravels. Equivalent b₁-τ_c relationships were derived from the flume tests as compared to the theoretical b₁-τ_c relationship in the Wilson model. The b₀-b₁ and k_d-τ_c relationships followed power law relationships. This research supports the applicability of the nonlinear mechanistic detachment model for noncohesive gravels.

The association between fetal head position prior to vacuum extraction and pregnancy outcome.

To estimate the association of fetal head position prior to vacuum extraction (VE) and pregnancy outcome. A retrospective cohort study of singleton pregnancies who underwent VE. Pregnancy outcome of occipito-anterior (OA) position of the fetal head was compared to those with occipito-posterior (OP) position. Amongst overall 12,063 women undergoing trial of labor, there were 1118 (9.2%) VE deliveries. Of them, 871 (77.9%) had OA and 247 (22.1%) had OP position of the fetal head. Except for a higher rate of nulliparity in the OA group, no significant differences between the groups regarding pregnancy complications and birthweight were noted. In the OP group, there were higher rates of prolonged 2nd-stage of labor as an indication for VE (49.8 vs. 36.5%, p < 0.001) and single detachment of vacuum cup (11.3 vs. 6.7%, p = 0.02) without any increased risk of failed extraction. Higher risks for sub-galeal hematoma (aOR = 4.36, p = 0.03) and low 5-min Apgar score (aOR = 4.63, p = 0.02) were observed in the OP group with otherwise similar rates of adverse maternal and neonatal outcomes. Among women undergoing VE, OP position is associated with higher rate of vacuum cup detachment, low 5-min Apgar score and increased risk for sub-galeal hematoma with otherwise similar rates of adverse maternal and neonatal outcomes.

Mercury removal from graphene by bombardment with xenon clusters: Computer simulation

Molecular dynamics simulation of the bombardment of a target with a Xe13cluster beam at energies of 5–30 eV and incidence angles of 0°–60° aiming to remove a mercury film from partially hydrogenated imperfect graphene has been performed. The graphene is completely cleaned of mercury at a cluster energy of EXe ≥ 15 eV. It has been revealed that the mercury film tends to form a droplet. Mercury is removed from the graphene film via sputtering of single atoms and droplet detachment. The energy of interaction of mercury with graphene is very low and weakly depends on the incident beam energy. The horizontal mobility of atoms in the liquid metal film has a significantly higher value than their vertical mobility. A stress in graphene resulting from forces normal to the sheet plane is noticeably higher than that due to forces acting in its plane. Bombardment at an angle of incidence of 45° is more efficient than that at incidence angles of 0° and 60° and leads to lower graphene roughness.