Subject: Engineering, Control & Systems Engineering Keywords: continuous co-phase traction power supply system (CCTPSS); traction electric network; directional protective relaying(dpr); amplitude comparison of traveling wave; VMD; modulus maximum
Online: 27 October 2019 (15:24:24 CET)
Directional protective relaying based on amplitude comparison of traveling wave on continuous co-phase auto-transformer(AT) power transmission system was proposed. Phase-model transformation is used for decoupling transient fault signals and get aerial mode component. The forward and backward traveling wave are obtained by calculating aerial mode component, then the intrinsic mode function(IMF) components can be obtained through Variational Mode Decomposition(VMD), the module maxima are obtained through calculating the IMF components. The fault direction is determined by the ratio of fault components. If two faults relays at the ends of electric traction networks detect a fault to be in the forward direction, the fault occurred in the internal area, the protection would operate properly. The simulation tests indicate that the protection scheme is feasible, and the proposed protection method can discriminate internal faults from external faults under various fault types, and its performances are immune to fault initial angle, ground resistance, etc.
ARTICLE | doi:10.20944/preprints202010.0537.v1
Subject: Physical Sciences, Acoustics Keywords: Cranial Traction Therapy; Correcting Facial Asymmerty
Online: 27 October 2020 (07:58:12 CET)
The purpose of this study is to develop a cranial traction therapy program to help correct facial asymmetry of the hard tissues through the means of the treatment of soft tissues—a non-surgical therapeutic method for the correcting of facial asymmetry. We have formed a group of experts who have agreed to the study. In the primary survey, open questions were used. In the second survey, the results of the first survey were summarized and the degree of agreement was presented to the questions in each category. In the third survey, we conducted a statistical analysis of the degree of agreement on each item of question. All surveys also performed email. The distribution was calculated using the SPSS (ver.23.0) program, and the mean difference between the result and X² was calculated. The significance level was set to p<.05. Most of the questions attained a certain level of consensus by the experts (average of 4.0 or higher), it can be said that most are important and suitable questions. the results regarding the degree of importance for each of the points of evaluation made by the groups of experts in both the second and third stage of the cranial traction therapy program were verified using content validity ratio (CVR 77). The ratio for the cranial traction 13 points of evaluation was within the range of 0.40∼1.00, so the Delphi program for the cranial traction therapy verified that the content was valid.
ARTICLE | doi:10.20944/preprints202207.0142.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: brachial plexus; traction injury; surgical treatment; electrostimulation
Online: 9 July 2022 (16:47:09 CEST)
As the problem of traction injuries to brachial plexus is a common one and of high socio-economic significance, the analysis of the surgical outcomes in patients with this pathology is significant for neurosurgery, neurology, traumatology-orthopedics, and rehabilitation. The aim of the research is to compare the short-term outcomes of using various surgical methods for managing patients with closed traction injuries of brachial plexus. Material and methods. The research involved 61 patients with closed traction injury of brachial plexus divided into two groups homogeneous in sex, age and severity of their neurological deficit: Group I – 33 patients who underwent microsurgical neurolysis, Group II – 28 patients who underwent microsurgical neurolysis combined with one-level electrostimulation. The dynamic assessment of clinical and functional status of upper limbs was performed using scale methods and electrophysiological monitoring. Results. The research revealed a more evident recovery of the upper limb function in Group II patients suggesting the method of microsurgical neurolysis combined with electrostimulation to be preferable in case of closed traction injuries to brachial plexus. Conclusion. The combination of microsurgical neurolysis with one-level electrostimulation improves the short-term outcomes of surgical treatment in patients with closed traction injuries of brachial plexus due to a sooner decrease in pain in postoperative period, and positive dynamics of clinical and electrophysiological parameters.
Subject: Engineering, Automotive Engineering Keywords: slip; gross traction; soil structure; soil bulk deformation
Online: 11 June 2021 (11:03:10 CEST)
One of the most important parameters that characterize the traction-coupling properties of a wheeled tractor is its slip. The more tractor's gross traction, the higher its traction-coupling properties. But, this gross traction should not exceed its maximum possible value, which, in turn out, is to be determined by the maximum permissible slip. This article provides the equation to calculate this crucial parameter and establishes the dependencies between the tractor's slip and soil structure coefficient. It was shown that the value basically depends on such soil characteristics as the bulk deformation coefficient and the coefficient of rolling resistance. Calculations showed that for the average value of the soil bulk deformation coefficient at, the average value of rolling resistance coefficient at 0.16, the ratio value of the maximum permissible soil pressure to the tractor wheel rolling radius at the maximum permitted amount slip of the tractor wheels should not exceed 15%. With more slip, the soil structure deteriorates significantly. In this case, its structure coefficient may be less than critical, equal to 0.4.
ARTICLE | doi:10.20944/preprints201707.0032.v1
Subject: Earth Sciences, Environmental Sciences Keywords: asphalt; concrete; runway; highway; traction; British Pendulum Tester; safety
Online: 14 July 2017 (10:11:43 CEST)
Volcanic ash deposited on paved surfaces during volcanic eruptions often compromises skid resistance, which is a major component of safety. We adopt the British pendulum test method in laboratory conditions to investigate the skid resistance of road asphalt and airfield concrete surfaces covered by volcanic ash sourced from various locations in New Zealand. Controlled variations in ash characteristics include type, depth, wetness, particle size and soluble components. We use Stone Mastic Asphalt (SMA) for most road surface experiments but also test porous asphalt, line-painted road surfaces, and a roller screed concrete mix used for airfields. Due to their importance for skid resistance, SMA surface macrotexture and microtexture are analysed with semi-quantitative image analysis, microscopy and a standardised sand patch volumetric test, which enables determination of the relative effectiveness of different cleaning techniques. We find that SMA surfaces covered by thin deposits (~1 mm) of ash result in skid resistance values slightly lower than those observed on wet uncontaminated surfaces. At these depths, a higher relative soluble content for low-crystalline ash and a coarser particle size results in lower skid resistance. Skid resistance results for relatively thicker deposits (3-5 mm) of non-vesiculated basaltic ash are similar to those for thin deposits. There are similarities between road asphalt and airfield concrete, although there is little difference in skid resistance between bare airfield surfaces and airfield surfaces covered by 1 mm of ash. Based on our findings, we provide recommendations for maintaining road safety and effective cleaning techniques in volcanic ash environments.
ARTICLE | doi:10.20944/preprints202107.0345.v1
Subject: Engineering, Automotive Engineering Keywords: Electrified railway; Fourier transform; Harmonic resonance; Overvoltage; Power Quality; Traction power supply
Online: 15 July 2021 (09:35:34 CEST)
Harmonic resonances are part of the Power Quality (PQ) problems of electrified railways and have serious consequences for the continuity of service and integrity of components in terms of overvoltage stress. The interaction between Traction Power Stations (TPSs) and trains that causes line resonances is briefly reviewed showing the dependence on infrastructure conditions. The objective is real-time monitoring of resonance conditions seen first of all from the onboard panto-graph interface, but it is equally applicable at TPS terminals. Voltage and current spectra, and de-rived impedance and power spectra, are analyzed proposing compact and efficient methods based on Short-Time Fourier Transform, suitable for real-time implementation with the hardware avail-able for energy metering and harmonic interference monitoring. The methods are tested by sweeping long recordings taken at some European railways, covering cases of longer and shorter supply sections, with a range of resonance frequencies of about one decade. They give insight into the spectral behavior of resonances, their dependency on position and change over time, and criteria to recognize genuine infrastructure resonances from rolling stock emissions.
ARTICLE | doi:10.20944/preprints202204.0312.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Tensional homeostasis; Traction microscopy; Gastric cancer cells; E-cadherin mutations; Extra-cellular matrix proteins
Online: 30 April 2022 (05:18:13 CEST)
In epithelia, breakdown of tensional homeostasis is closely associated with E-cadherin dysfunction and disruption of tissue function and integrity. In this study, we investigated the effect of E-cadherin mutations affecting distinct protein domains on tensional homeostasis of gastric cancer cells. We used micropattern traction microscopy to measure temporal fluctuations of cellular traction forces in AGS cells transfected with the wild-type E-cadherin or with variants affecting the extracellular, the juxtamembrane, and the intracellular domains of the protein. We focused on the dynamic aspect of tensional homeostasis, namely the ability of cells to maintain a consistent level of tension, with low temporal variability around a set point. Cells were cultured on hydrogels micropatterned with different extracellular matrix (ECM) proteins to test whether the ECM adhesion impacts cell behavior. A combination of Fibronectin and Vitronectin was used as a substrate that promotes the adhesive ability of E-cadherin dysfunctional cells, whereas Collagen VI was used to test an unfavorable ECM condition. Our results showed that mutations affecting distinct E-cadherin domains influenced differently cell tensional homeostasis, and pinpointed the juxtamembrane and intracellular regions of E-cadherin as the key players in this process. Furthermore, Fibronectin and Vitronectin might modulate cancer cell behavior towards tensional homeostasis.
ARTICLE | doi:10.20944/preprints202111.0270.v2
Subject: Engineering, Electrical & Electronic Engineering Keywords: three-phase unbalance rate (TPUR); negative phase sequence unbalance rate (NPSUR); special transformer wiring (STW); Railway System Transport Cable (RSTC); Traction Supply Substation (TSS)
Online: 14 December 2021 (15:26:32 CET)
Because imbalanced power will cause the loss of the propulsion motor of the railway vehicle, and the increase in temperature will shorten the service life of the electric vehicle. Not only this, but also increase the cost of electricity and maintenance. In the past, the industry only focused on methods to improve power quality such as load capacity, relay setting, and harmonic resolution. Now, the consider of three-phase unbalance rate (TPUR) must be applied. I propose special transformers wiring (STW) to improve the three unbalance rates and provide different transformer wiring methods. According to the IEEE Committee, in the future, power companies will need to install balanced relay stations to improve three-phase unbalance rate. the internal regulations of Taipower must be less than 4.5% (voltage unbalance rate (NPSUR)of 2.5% and motor temperature rise of 12.5%). the derivation of the transformer "three-phase unbalance rate" model is the focus of the railway system. This research is based on the model derivation of different wiring methods to improve the hot problem caused by the three-phase imbalance and improve the service life of the train. And pointed out that Scott, Le-Blanc, Modified-Woodbridge three wiring methods can be applied to future railway system routes to improve the three-phase unbalance rate, in line with the IEEE standard of less than 2%.