Chemically non-equilibrium model of decaying N2 arcs in a model circuit breaker

Nitrogen gas has been investigated as one of the candidate substitutes for SF6 in a high-voltage circuit breaker (HVCB) and also in a low-voltage interrupter. In this paper, a chemically non-equilibrium model was established to investigate N2 arc plasmas in the decaying phase during current interruption in a model circuit breaker. Unlike the conventional model assuming local thermodynamic equilibrium, i.e. both chemical equilibrium and thermal equilibrium, in this work a chemically non-equilibrium model was developed for N2 arc plasmas. Thermal non-equilibrium effects were neglected, meaning a one-temperature model was adopted. The developed model took into account 5 species such as N2, N, N2+, N+ and e-, and 22 chemical reactions including electron impact ionizations, heavy particles impact dissociations and their backward reactions. Temperature dependent reaction rates were used for all considered reactions. The species composition in N2 arc plasma was calculated by solving the mass conservation equation of each species considering diffusion, convection and reaction effects. Then the influence of the chemically non-equilibrium composition on the arc behavior was calculated by updating the thermodynamic and transport properties at each iterative step. Finally, for the decaying N2 arc plasma under a free recovery phase, the time evolutions were derived in the profiles of the temperature and the number densities for each species. The results in this work were compared with the calculated results based on the chemical equilibrium assumption. © 2015 IEEE

Uncertainty Theory Based Reliability-Centric Cyber-Physical System Design

Cyber-physical systems (CPSs) are built from, and depend upon, the seamless integration of software and hardware components. The most important challenge in CPS design and verification is to design CPS to be reliable in a variety of uncertainties, i.e., unanticipated and rapidly evolving environments and disturbances. The costs, delays and reliability of the designed CPS are highly dependent on software-hardware partitioning in the design. The key challenges in partitioning CPSs is that it is difficult to formalize reliability characterization in the same way as the uncertain cost and time delay. In this paper, we propose a new CPS design paradigm for reliability assurance while coping with uncertainty. To be specific, we develop an uncertain programming model for partitioning based on the uncertainty theory, to support the assured reliability. The uncertainty effect of the cost and delay time of components to be implemented can be modeled by the uncertainty variables with uncertainty distributions, and the reliability characterization is recursively derived. We convert the uncertain programming model and customize an improved heuristic to solve the converted model. Experiment results on some benchmarks and random graphs show that the uncertain method produces the design with higher reliability. Besides, in order to demonstrate the effectiveness of our model for in coping with uncertainty in design stage, we apply this uncertain framework and existing deterministic models in the design process of a sub-system that is used in real world subway control. The system implemented based on the uncertain model works better than the result of deterministic models. The proposed design paradigm has the potential to be generalized to the design of CPSs for greater assurances of safety and security under a variety of uncertainties

High psychological stress levels related to delivery can increase the occurrence of postpartum mental disorders

ObjectiveThe study sought to explore the relationship between high psychological stress levels related to delivery and postpartum mental disorders.MethodsA total of 284 parturients were included in the study from July 2021 to January 2022. The stress level at 1 month postpartum was assessed by the Impact of Event Scale-Revised (IES-R). Parturients with an IES-R score ≤ 9 were included in the low psychological stress level group, and those with an IES-R score > 9 were included in the high psychological stress level group. The Edinburgh Postnatal Depression Scale (EPDS), Union Physio-Psycho-Social Assessment Questionnaire (UPPSAQ-70), Symptom Checklist-90 (SCL-90) and Mini-International Neuropsychiatric Interview (M.I.N.I.) were conducted at 42 ± 7 days postpartum to assess the mental health of parturients.The parturients’ mental health after birth was assessed by the EPDS, UPPSAQ-70, and SCL-90. Semi-structured diagnostic interviews were conducted at 42 ± 7 days postpartum by using the M.I.N.I.ResultsThe incidence rate of postpartum mental disorders was 20.42% (58/284), the incidence rates of postpartum depression, anxiety disorders, obsessive-compulsive disorder and posttraumatic stress disorder were 17.96% (51/284), 11.97% (34/284), 4.58% (13/284) and 1.41% (4/284), respectively, and the comorbidity rate was 58.62% (34/58). A history of mental disorders and pregnancy complications were risk factors for postpartum depression (p = 0.028, p = 0.040, respectively); a history of mental disorders, a lack of physical exercise, partner violence and pregnancy complications were risk factors for postpartum anxiety disorders (p = 0.003, p = 0.007, p = 0.031, p = 0.048, respectively); and the delivery of female infants was a risk factor for postpartum obsessive-compulsive disorder (p = 0.022).The risk of postpartum depression, anxiety disorders and obsessive-compulsive disorder was 9.125 times (95% CI = 3.900 ~ 21.349, p < 0.01), 7.310 times (95% CI = 2.588 ~ 20.649, p < 0.01) and 6.259 times (95% CI = 1.347 ~ 29.093, p < 0.01) higher in postpartum women with high psychological stress levels related to delivery than in those with low psychological stress levels, respectively.ConclusionThe incidence of postpartum mental disorders is high and has a positive correlation with the level of psychological stress. This may lead to a new perspective of the effect of psychological stress on postpartum mental disorders and attract more attention to other mental disorders in addition to postpartum depression

Fluid Model of Plasma-Liquid Interaction: The Effect of Interfacial Boundary Conditions and Henry\u27s Law Constants

Plasma–liquid interaction is a critical area of plasma science, mainly because much remains unknown about the physicochemical processes occurring at the plasma–liquid interface. Besides a lot of experimental studies toward the interaction, a few fluid models have also been reported in recent years. However, the interfacial boundary conditions in the models are different and the Henry\u27s law constants therein are uncertain; hence, the accuracy and robustness of the simulation results are doubtable. In view of this, three 1D fluid models are developed for the interaction between a plasma jet and deionized water, each of which has a unique interfacial boundary condition as reported in the literature. It is found that the density distribution of reactive species is nearly independent of the interfacial boundary conditions in both the gas and liquid phases, except for that in the interfacial gas layer with a thickness of several tens of micrometers above water. The densities of the reactive species with high Henry\u27s law constants (H \u3e 104) are much different in such gas layers among the interfacial boundary conditions. Moreover, some Henry\u27s law constants are changed in the models according to their uncertainty reported in the literature, and only the reactive species with low Henry\u27s law constants (H \u3c 1) have their aqueous densities following the change. These densities are very low in the plasma-activated water. It could be concluded that the simulation of plasma–liquid interaction is generally independent of the interfacial boundary conditions and the uncertainty in Henry\u27s law constants

A Simple and Rapid Puncture Method for Draining Hematoma in Pontine Hemorrhage

We present a patient with pontine hemorrhage. On admission, the patient was in a comatose state (Glasgow coma scale, 3). Due to rapid deterioration of his breathing, we immediately performed a direct puncture to the hematoma site. We present a simple and rapid puncture method for drainage of hematomas. The method is described and discussed in detail in this article. The described technique may be beneficial in emergency situations where the condition of the patient, particularly their respiration is declining rapidly

Preliminary findings on the effect of childhood trauma on the functional connectivity of the anterior cingulate cortex subregions in major depressive disorder

ObjectivesChildhood trauma (CT) is a known risk factor for major depressive disorder (MDD), but the mechanisms linking CT and MDD remain unknown. The purpose of this study was to examine the influence of CT and depression diagnosis on the subregions of the anterior cingulate cortex (ACC) in MDD patients.MethodsThe functional connectivity (FC) of ACC subregions was evaluated in 60 first-episode, drug-naïve MDD patients (40 with moderate-to-severe and 20 with no or low CT), and 78 healthy controls (HC) (19 with moderate-to-severe and 59 with no or low CT). The correlations between the anomalous FC of ACC subregions and the severity of depressive symptoms and CT were investigated.ResultsIndividuals with moderate-to severe CT exhibited increased FC between the caudal ACC and the middle frontal gyrus (MFG) than individuals with no or low CT, regardless of MDD diagnosis. MDD patients showed lower FC between the dorsal ACC and the superior frontal gyrus (SFG) and MFG. They also showed lower FC between the subgenual/perigenual ACC and the middle temporal gyrus (MTG) and angular gyrus (ANG) than the HCs, regardless of CT severity. The FC between the left caudal ACC and the left MFG mediated the correlation between the Childhood Trauma Questionnaire (CTQ) total score and HAMD-cognitive factor score in MDD patients.ConclusionFunctional changes of caudal ACC mediated the correlation between CT and MDD. These findings contribute to our understanding of the neuroimaging mechanisms of CT in MDD

Experimental observation of topological Fermi arcs in type-II Weyl semimetal MoTe2

Weyl semimetal is a new quantum state of matter [1-12] hosting the condensed matter physics counterpart of relativisticWeyl fermion [13] originally introduced in high energy physics. The Weyl semimetal realized in the TaAs class features multiple Fermi arcs arising from topological surface states [10, 11, 14-16] and exhibits novel quantum phenomena, e.g., chiral anomaly induced negative mag-netoresistance [17-19] and possibly emergent supersymmetry [20]. Recently it was proposed theoretically that a new type (type-II) of Weyl fermion [21], which does not have counterpart in high energy physics due to the breaking of Lorentz invariance, can emerge as topologically-protected touching between electron and hole pockets. Here, we report direct spectroscopic evidence of topological Fermi arcs in the predicted type-II Weyl semimetal MoTe2 [22-24]. The topological surface states are confirmed by directly observing the surface states using bulk-and surface-sensitive angle-resolved photoemission spectroscopy (ARPES), and the quasi-particle interference (QPI) pattern between the two putative Fermi arcs in scanning tunneling microscopy (STM). Our work establishes MoTe2 as the first experimental realization of type-II Weyl semimetal, and opens up new opportunities for probing novel phenomena such as exotic magneto-transport [21] in type-II Weyl semimetals.Comment: submitted on 01/29/2016. Nature Physics, in press. Spectroscopic evidence of the Fermi arcs from two complementary surface sensitive probes - ARPES and STS. A comparison of the calculated band structure for T_d and 1T' phase to identify the topological Fermi arcs in the T_d phase is also included in the supplementary informatio

Parker Solar Probe Observations of High Plasma Beta Solar Wind from Streamer Belt

In general, slow solar wind from the streamer belt forms a high plasma beta equatorial plasma sheet around the heliospheric current sheet (HCS) crossing, namely the heliospheric plasma sheet (HPS). Current Parker Solar Probe (PSP) observations show that the HCS crossings near the Sun could be full or partial current sheet crossing (PCS), and they share some common features but also have different properties. In this work, using the PSP observations from encounters 4 to 10, we identify streamer belt solar wind from enhancements in plasma beta, and we further use electron pitch angle distributions to separate it into HPS solar wind that around the full HCS crossings and PCS solar wind that in the vicinity of PCS crossings. Based on our analysis, we find that the PCS solar wind has different characteristics as compared with HPS solar wind: a) PCS solar wind could be non-pressure-balanced structures rather than magnetic holes, and the total pressure enhancement mainly results from the less reduced magnetic pressure; b) some of the PCS solar wind are mirror unstable; c) PCS solar wind is dominated by very low helium abundance but varied alpha-proton differential speed. We suggest the PCS solar wind could originate from coronal loops deep inside the streamer belt, and it is pristine solar wind that still actively interacts with ambient solar wind, thus it is valuable for further investigations on the heating and acceleration of slow solar wind