reverse direction
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2022 ◽  
pp. 152660282110709
Author(s):  
Jordan R. Stern ◽  
Xuan-Binh D. Pham ◽  
Jason T. Lee

Purpose: The objective of this study is to describe a novel method for creating a distal landing zone for thoracic endovascular aortic repair (TEVAR) in chronic aortic dissection. The technique is described in a patient with prior total arch and descending aortic replacement, with false lumen expansion. Technique: A cheese-wire endovascular septotomy was desired to create a single lumen above the celiac axis. To avoid dividing the septum caudally across the visceral segment, we performed a modified septotomy in a cephalad direction. Stiff wires were passed into the prior surgical graft, through true lumen on the right and false lumen on the left. An additional wire was passed across an existing fenestration at the level of the celiac axis, and snared and externalized. 7F Ansel sheaths were advanced and positioned tip-to-tip at the fenestration. Using the stiff wires as tracks, the through-wire was pushed cephalad to endovascularly cut the septum. Angiogram demonstrated successful septotomy, and TEVAR was performed to just above the celiac with successful aneurysm exclusion and no endoleak or retrograde false lumen perfusion. Follow-up computed tomography angiogram (CTA) showed continued exclusion without false lumen perfusion. Conclusions: This novel modification in a reverse direction provides an alternative method for endovascular septotomy, when traditional septotomy may threaten the visceral vessels.


Author(s):  
Thejaswini. R

Abstract: A good electrical power system ensures the availability of electrical power without any of the interruption to every load connected to it. Generally the power is transmitted through the high voltage transmission lines. Normally these are the types of the devices which are can be of the batteries or of the ultra-capacitors these devices stores energy as the DC Charges. Here the energy can be obtained from the AC lines which are connected to the grid lines and these can be processed either type can be wired type or the wireless. The processes involved they will work in the reverse direction in which the power present which can be fed back to the grid lines and the batteries which is of the regenerative braking type when the vehicle present in the idle V2G state. Here the typical placement of the various different types of the converters in an EV positioning systems along with the power converting storage type of the devices here the conversion present can be of the DC-AC or DC-DC types. Here the description of the power converter electronic devices are provided and the classification of the AC-AC converters. Index Terms: LLC, SRC , MOSFET, ZVS FB Converter, BCM, OLPT, PMPT, RIPT, V2G.


2021 ◽  
Vol 12 (6) ◽  
pp. 1-28
Author(s):  
Jie Qiao ◽  
Ruichu Cai ◽  
Kun Zhang ◽  
Zhenjie Zhang ◽  
Zhifeng Hao

Identification of causal direction between a causal-effect pair from observed data has recently attracted much attention. Various methods based on functional causal models have been proposed to solve this problem, by assuming the causal process satisfies some (structural) constraints and showing that the reverse direction violates such constraints. The nonlinear additive noise model has been demonstrated to be effective for this purpose, but the model class does not allow any confounding or intermediate variables between a cause pair–even if each direct causal relation follows this model. However, omitting the latent causal variables is frequently encountered in practice. After the omission, the model does not necessarily follow the model constraints. As a consequence, the nonlinear additive noise model may fail to correctly discover causal direction. In this work, we propose a confounding cascade nonlinear additive noise model to represent such causal influences–each direct causal relation follows the nonlinear additive noise model but we observe only the initial cause and final effect. We further propose a method to estimate the model, including the unmeasured confounding and intermediate variables, from data under the variational auto-encoder framework. Our theoretical results show that with our model, the causal direction is identifiable under suitable technical conditions on the data generation process. Simulation results illustrate the power of the proposed method in identifying indirect causal relations across various settings, and experimental results on real data suggest that the proposed model and method greatly extend the applicability of causal discovery based on functional causal models in nonlinear cases.


Author(s):  
Robert Adams ◽  
Jinjiang Xiao ◽  
Michael Cross ◽  
Max Deffenbaugh

Switched reluctance motors may be advantageous when used as the primary motor for an electric submersible pump system.  They are less susceptible to jamming failures due to their high starting torque and ability to reverse direction.  Driving these motors requires well-timed pulse waveforms and precise control of the motor based on its rotational position.  In general, voltage-based sensing and control systems at the surface see highly unpredictable waveforms with excessive ringing behaviour due to the impedance characteristics of the long cabling between the surface controller and the downhole motor system.  In this work, a system is detailed which monitors the current waveforms on the motor coil excitation conductors at the surface as a source of motor performance feedback and control.  State-space modelling of the system shows stable current waveforms at the surface controller for both short and long interconnect cable systems.  A laboratory demonstration of the surface controller, interconnect cabling, and motor system is shows excellent agreement with the current and voltage waveforms predicted by the state-space system model.


2021 ◽  
Author(s):  
Robert Adams ◽  
Jinjiang Xiao ◽  
Michael Cross ◽  
Max Deffenbaugh

Abstract Switched reluctance motors may be advantageous when used as the primary motor for an electric submersible pump system. They are less susceptible to jamming failures due to their high starting torque and ability to reverse direction. Driving these motors requires well-timed pulse waveforms and precise control of the motor based on its rotational position. It is demonstrated that the pulses required to drive switched reluctance motors can still be applied over along cable lengths. Additionally, the current at the surface can be used to monitor and control the operation of the motor downhole, even with long cable lengths separating the surface power source and downhole motor.


2021 ◽  
Vol 12 ◽  
Author(s):  
Peng Huang ◽  
Yuqing Hou ◽  
Yixin Zou ◽  
Xiangyu Ye ◽  
Rongbin Yu ◽  
...  

Background: Primary biliary cholangitis (PBC) is an autoimmune disease and is often accompanied by thyroid dysfunction. Understanding the potential causal relationship between PBC and thyroid dysfunction is helpful to explore the pathogenesis of PBC and to develop strategies for the prevention and treatment of PBC and its complications.Methods: We used a two-sample Mendelian randomization (MR) method to estimate the potential causal effect of PBC on the risk of autoimmune thyroid disease (AITD), thyroid-stimulating hormone (TSH) and free thyroxine (FT4), hyperthyroidism, hypothyroidism, and thyroid cancer (TC) in the European population. We collected seven datasets of PBC and related traits to perform a series MR analysis and performed extensive sensitivity analyses to ensure the reliability of our results.Results: Using a sensitivity analysis, we found that PBC was a risk factor for AITD, TSH, hypothyroidism, and TC with odds ratio (OR) of 1.002 (95% CI: 1.000–1.005, p = 0.042), 1.016 (95% CI: 1.006–1.027, p = 0.002), 1.068 (95% CI: 1.022–1.115, p = 0.003), and 1.106 (95% CI: 1.019–1.120, p = 0.042), respectively. Interestingly, using reverse-direction MR analysis, we also found that AITD had a significant potential causal association with PBC with an OR of 0.021 (p = 5.10E−4) and that the other two had no significant causal relation on PBC.Conclusion: PBC causes thyroid dysfunction, specifically as AITD, mild hypothyroidism, and TC. The potential causal relationship between PBC and thyroid dysfunction provides a new direction for the etiology of PBC.


2021 ◽  
Author(s):  
Yanfang Wang ◽  
Jingmin Yao

Abstract Accompanied with the increasing complicated global value chain (GVC) networks is the carbon emission transfers among countries. Utilizing the complex network analysis alongside quadratic assignment procedure (QAP), this paper detects the community structure and influencing forces of the emission transfers under GVCs. The results imply that the bipolar structure of the network transformed gradually to tripolar owing largely to the surging of carbon emissions from China. Evidence on the existence of environmental Kuznets curve (EKC) in the emission transfers from high-income countries to low-income countries, and a U-shape relationship in the transfers in the reverse direction, suggesting that growing carbon emissions from both low- and high-income countries transferred to other high-income countries gradually. Gaps in technology, especially in patent applications, between source and destination countries played an important role therein. JEL: F14, F18, Q56, R15


2021 ◽  
Author(s):  
Junfei Ma ◽  
Shachinthaka D. Dissanayaka Mudiyanselage ◽  
Woong June Park ◽  
Mo Wang ◽  
Ryuta Takeda ◽  
...  

AbstractThe prevailing view regarding intracellular RNA trafficking in eukaryotic cells describes that RNAs transcribed in the nucleus either stay in the nucleus or cross the nuclear envelope entering the cytoplasm for function. Interestingly, emerging evidence illustrates numerous functional RNAs trafficking in the reverse direction from the cytoplasm to the nucleus. However, the mechanism underlying the RNA nuclear import has not been well elucidated. Viroids are single-stranded circular noncoding RNAs that infect plants. Using nuclear-replicating viroids as a model, we showed that cellular Importin alpha-4 is likely involved in viroid RNA nuclear import, empirically supporting the involvement of Importin-based cellular pathway in RNA nuclear import. We also confirmed the involvement of a cellular protein (Virp1) that binds both Importin alpha-4 and viroids. Furthermore, a conserved C-loop in nuclear-replicating viroids is critical for Virp1 binding. Disrupting C-loop impairs Virp1 binding, viroid nuclear accumulation and infectivity. Further, C-loop exists in a subviral satellite noncoding RNA that relies on Virp1 for nuclear import. These results have significant implications for understanding the infection process of subviral agents. In addition, our data outline a cellular pathway responsible for the nuclear import of RNAs and uncover a 3-dimensional RNA motif-based regulation over RNA nuclear import.


Author(s):  
Hossein Soleimankhani ◽  
Greg MacRae ◽  
Tim Sullivan

Single-storey systems with different hysteretic characteristic are subjected to impulse-type short duration and long duration earthquake records to investigate the effects of hysteretic behaviour and ground motion characteristics on the seismic response. EPP, bilinear, Takeda, SINA, and flag-shaped hysteretic models loops are considered and an energy approach is taken to explain the inelastic behaviour. The first part of the work is based on analyses of the single-storey systems without any torsion, however; torsional irregularity is considered in the later analyses. It is shown that structures with the same backbone curve, but different hysteretic characteristics, tend to experience the same maximum response under short duration earthquake records, where there is one major displacement excursion. The likelihood of further displacement in the reverse (i.e. negative) direction is characterized using energy methods and free vibration analyses along with a new proposed “oscillation resistance ratio (ORR)” are employed to improve the understanding of the seismic response. Hysteretic models with low ORR, such as SINA and flag-shaped, are shown to have a greater likelihood of higher absolute displacement response in the negative direction compared with those with fatter hysteretic loops. The understanding of the response in terms of energy reconciles some differences in the ability of initial stiffness versus secant stiffness based methods to predict peak displacement demands with account for different ground motion characteristics. The same peak displacements in the primary direction was also observed for structures with stiffness/strength eccentricities under an impulse-type earthquake record. However, during unloading, the elastic energy stored in the out-of-plane elements is released causing greater displacement on the weak side in the reverse direction.


2021 ◽  
Vol 5 (11) ◽  
pp. 47-53
Author(s):  
Jing Song

This article discusses the problems existing in the teaching of Logistics and the urgency of its curriculum reform, introduces the concept of outcome-based education (OBE) into the teaching process of Logistics, designs the teaching in a reverse direction guided by the results, and implements the teaching design in the form of flipped classroom. A “student-centered” teaching process endows students with stronger autonomy and initiative and encourages them to cooperate with each other. This teaching process provides new ideas and methods for the teaching reform of Logistics as well as the cultivation of excellent logistics talents.


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