Synchronous Zone Research Articles

Himalayan Leucogranites: Field Relationships and Tectonics

Himalayan peraluminous leucogranites were derived from in-situ melting of sillimanite + K-feldspar-bearing pelite-migmatite, and were transported via layer-parallel sill complexes and cross-cutting dykes to feed giant sills up to 5 km thick. Partially melted Himalayan middle crust was extruded southwards between two large-scale, north-dipping, synchronous ductile shear zones: the Main Central Thrust (MCT) below and the low-angle normal fault South Tibetan Detachment (STD) above. U-Th/Pb monazite dating constrains granite melting to ~25–18.5 Ma in Manaslu and ~24–13 Ma in Everest-Makalu. The Manaslu sheeted sill complex was emplaced by progressive underplating with the oldest intrusions structurally above younger intrusions. Heat was dominantly derived by internal radioactive heating from crustal thickening with little or no contribution from shear heating along the MCT or from the mantle.

Analysis of leakage flux, losses, and temperature in large synchronous generator end zone under the multi‐layer screen thickness based on novel iterative method

AbstractThe multi‐layer screen is the key component in the large synchronous generator end zone. The leakage flux, losses, and temperature of end components are significantly affected by the thickness of multi‐layer screen in the synchronous generator. To investigate the influence of multi‐layer screen thickness on the end leakage flux, losses, and temperature in the synchronous generator end zone, 1407MVA nuclear power synchronous generator is studied. Three‐dimensional transient electromagnetic field model of synchronous generator end zone is established. Three‐dimensional transient electromagnetic field in the end zone of 1407MVA synchronous generator with the multi‐layer screen is calculated based on the novel iterative method. The flux density of end components is compared and studied in the end zone under the variation of multi‐layer screen thickness. Influence of the different thicknesses of multi‐layer screen on the losses of the shield plate, screen, finger plate, and stator end core is researched. The losses of end components obtained from 3D end electromagnetic field calculation are applied to the end zone as the heat source in the three‐dimensional fluid and thermal coupled field. The temperature distribution of the end components is determined. The accuracy of the calculated results is validated by the experimental values.

Influence of Longitudinal Joint Setting and Synchronous Cooling Zone on High Altitude Region’s Dam Construction

The crack problem in mass concrete is a difficult problem to thoroughly solve, especially for the crack of dam construction in high-altitude regions. High altitude regions have the fundamental features of a dry climate and strong solar radiation. When dam construction is performed under these special climate conditions, temperature control and crack prevention become more difficult problems. Based on the high altitude region’s dam construction conditions, the existing temperature control measures were optimized by combining the three-dimensional finite element method. The synchronous cooling zone’s temperature control technique is adopted to lower the temperature gradient in the dam’s height direction, coordinate the deformation of the upper and lower layers, and reduce mutual constraints between the upper and lower layers to further reduce the temperature stress. Calculation results show that the adoption of synchronous cooling zones and the set of longitudinal joints can effectively reduce mutual constraints, increase the safety factor, and prevent cracks. This method can be considered an important reference to dam projects in high-altitude regions.

Impact of the Separation of the Continental Europe Power System on January 8, 2021 on the Work of the Bosnia and Herzegovina Power System

Abstract After the separation of the Continental Europe power system on 8th January 2021 in two synchronous zones, the electric power system of BiH (EPS BiH) shows a significant increase in frequency and voltages and oscillations of active and reactive power. The paper discusses the operation of protective devices in the BiH power system when the system was operating at high frequencies and voltages and had oscillations of active and reactive power. As a consequence of this behaviour in the EPS BiH there was activation of distance protections (DP) in substation (SS) 220/110 kV Prijedor 2 and overhead transmission lines (OHL) 220 kV Prijedor 2 - Međurić and OHL 220 kV Prijedor 2 – Sisak were disconnected. This was followed by activation of generator protections (reverse power protection and under-excitation protection) and outages of generator units in Hydro Power Plant (HPP) Salakovac, Thermal Power Plant (TPP) Kakanj, HPP Mostar, HPP Bočac, HPP Peć Mlini and HPP Jajce 2.

Studies on of phase error oscillations in a class of third-order optical phase locked loop and its effect on a slave optical phase locked loop

Dynamics of a third-order optical phase locked loop (OPLL) with a resonant type loop filter (LF) has been studied analytically and numerically. The range of stable synchronous operating zone of such OPLL has been estimated analytically in system and signal parameters and obtained predictions are in good agreement with numerical results. Beyond the stable region, it is found that chaotic oscillation of phase error occurs through a sequence of period doubling bifurcation. In addition to this, tracking of such periodic as well as chaotic dynamics of third-order OPLL by another OPLL in master-slave configuration has also been explored here. The tracking is possible by slave OPLL within a very short range of effective frequency offset by keeping other design parameters within the stable mode of operation. The synchronization of the master and slave OPLLs has been studied in generalized sense by considering auxiliary system. The study is very important and helpful for optical signal processing and also in chaos-based secure communication.

The strong effect of network resolution on electricity system models with high shares of wind and solar

Energy system modellers typically choose a low spatial resolution for their models based on administrative boundaries such as countries, which eases data collection and reduces computation times. However, a low spatial resolution can lead to sub-optimal investment decisions for wind and solar generation. Ignoring power grid bottlenecks within regions tends to underestimate system costs, while combining locations with different wind and solar capacity factors in the same resource class tends to overestimate costs. We investigate these two competing effects in a capacity expansion model for Europe’s power system with a high share of renewables, taking advantage of newly-available high-resolution datasets as well as computational advances. We vary the number of nodes, interpolating between a 37-node model based on country and synchronous zone boundaries, and a 1024-node model based on the location of electricity substations. If we focus on the effect of renewable resource resolution and ignore network restrictions, we find that a higher resolution allows the optimal solution to concentrate wind and solar capacity at sites with better capacity factors and thus reduces system costs by up to 10% compared to a low resolution model. This results in a big swing from offshore to onshore wind investment. However, if we introduce grid bottlenecks by raising the network resolution, costs increase by up to 23% as generation has to be sourced more locally at sites with worse capacity factors. These effects are most pronounced in scenarios where grid expansion is limited, for example, by low local acceptance. We show that allowing grid expansion mitigates some of the effects of the low grid resolution, and lowers overall costs by around 16%.

Synchronous colonic adenoma and intestinal marginal zone B-cell lymphoma associated with Crohn\u2019s disease: a case report and literature review

BackgroundLymphoma and dysplasia are rare complications of long-standing Crohn’s disease. We report an exceptional case of a synchronous intestinal marginal zone B-cell lymphoma (MALT lymphoma) and colonic adenoma in a Crohn’s disease patient.Case presentationA 50-year-old male patient presented with right lower quadrant for the last 9 months. He also had associated weight loss and diarrhea alternating with constipation. Ileo-colonoscopy revealed a pseudopolypoid appearance of the colonic and ileal mucosa with many discontinuous ulcerations with a 3 cm sessile polypoid mass at 17 cm from the anal verge. Histological examination of the polypoid lesion revealed an adenoma with high grade dysplasia, while the biopsies of colonic mucosa showed histologic features of Crohn’s disease. Abdominal computed tomography scan (CT scan) and magnetic resonance imaging (MRI) showed circumferential wall thickening of the colon and ileum, enlarged mesenteric lymph nodes and a sessile polypoid mass of the rectosigmoid junction. The patient was scheduled for an ileocoletectomy with resection of the upper rectum and ileorectostomy.The histological examination of the resected segment showed histologic features of Crohn’s disease, a recto-sigmoid polyp with high grade.dysplasia and extensive small lymphocytic infiltrate in both colonic and ileal wall which is strongly stained by CD20 and BCL2. The diagnosis of MALT lymphoma with adenoma on a background of Crohn’s disease was made.The patient successfully completed 8 cycles of Rituximab+ chlorambucil chemotherapy.Nowadays the patient is asymptomatic without evidence of lymphoproliferative recurrence 10 months after surgery.ConclusionWe report the first case in the literature of Malt lymphoma with colonic adenoma associated with Crohn’s disease, and discuss his unique macroscopic and histological features in a patient.Without immunosuppressive therapy.

Approaches to establishing voltage control requirements for distributed generation units

Analysis of Russian national regulation and technical standards requirements for generating equipment participation in voltage and reactive power control in the power system carried out. Summary of some international experience in voltage control organization under conditions of distributed generation units’ deep integration in public grid is presented in article. Advantages of voltage and reactive power control automation over decentralized and poorly coordinated control are substantiated. Problematic aspects of distributed generation units (including RES) integration, as well as ENTSO-E approaches to voltage and reactive power control in the synchronous zone of continental Europe are considered. Technical requirements of Deutsch and Danish regulations, regarding participation of distributed generation facilities in voltage control are given. Approaches to establishing voltage control requirements for distributed generation units’ operation with national power system are presented.

Numerical study of flow past oscillatory square cylinders at low Reynolds number

Abstract The present work reports a numerical investigation of the flow past an oscillatory square cylinder at R e = 100 . A fixed finite element immersed technique is proposed to solve the incompressible fluid–rigid body interaction problem. The study encompasses the analyses of the flow over a fixed cylinder and transverse to the flow and streamwise oscillating cylinders. The dimensionless frequency f r , i.e., the ratio between cylinder’s oscillation and Strouhal frequencies, and motion amplitude are used to characterize the flow pattern evolution and its action on the cylinder. First, to compute the flow over the cylinder, a mesh size is determined from a mesh sensitivity analysis where the drag and lift coefficients computed using the immersed method are compared with those obtained from a body-fitted mesh. A reasonable numerical convergence is found from such analyses. Second, the oscillating square cylinder cases are studied to describe the synchronization regions. To this end, an oscillating body motion is prescribed varying the frequency of the imposed displacement with a constant amplitude. The synchronization zones are determined when the aerodynamic coefficients exhibit the most significant variations. In particular, the lock-in phenomenon is observed at f r ≈ 1 for transversely oscillating square cylinders, confirming some aspects previously reported in the literature using other numerical techniques. In the present work, lock-in is determined at f r ≈ 2 for streamwise oscillating square cylinders, results is not longer found in the literature.

An Efficient Software Defined Data Transmission Scheme based on Mobile Edge Computing for the Massive IoT Environment

This paper presents a novel and efficient data transmission scheme based on mobile edge computing for the massive IoT environments which should support various type of services and devices. Based on an accurate and precise synchronization process, it maximizes data transmission throughput, and consistently maintains a flow’s latency. To this end, the proposed efficient software defined data transmission scheme (ESD-DTS) configures and utilizes synchronization zones in accordance with the 4 usage cases, which are end node-to-end node (EN-EN), end node-to-cloud network (EN-CN), end node-to-Internet node (EN-IN), and edge node-to-core node (EdN-CN); and it transmit the data by the required service attributes, which are divided into 3 groups (low-end group, medium-end group, and high-end group). In addition, the ESD-DTS provides a specific data transmission method, which is operated by a buffer threshold value, for the low-end group, and it effectively accommodates massive IT devices. By doing this, the proposed scheme not only supports a high, medium, and low quality of service, but also is complied with various 5G usage scenarios. The essential difference between the previous and the proposed scheme is that the existing schemes are used to handle each packet only to provide high quality and bandwidth, whereas the proposed scheme introduces synchronization zones for various type of services to manage the efficiency of each service flow. Performance evaluations show that the proposed scheme outperforms the previous schemes in terms of throughput, control message overhead, and latency. Therefore, the proposed ESD-DTS is very suitable for upcoming 5G networks in a variety of massive IoT environments with supporting mobile edge computing (MEC).

The extent of edema and tumor synchronous invasion into the subventricular zone and corpus callosum classify outcomes and radiotherapy strategies of glioblastomas

Background and purposeIrradiating glioblastoma preoperative edema (PE) remains controversial. We investigated the associations between tumors’ PE extent with invasion into synchronous subventricular zone and corpus callosum (sSVZCC) and treatment outcomes to provide the clinical evidence for radiotherapy decision-making. Material and methodsExtensive PE (EPE) was defined as PE extending ≥2 cm from the tumor edge and extensive progressive disease (EPD) as tumors spreading ≥2 cm from the preoperative tumor edge along PE. The survival and progression patterns were analyzed according to EPE and sSVZCC invasion. ResultsIn total, 136 patients were followed for a median of 74.9 (range, 47.6–102.1) months. The median overall survival and progression-free survival were 19.7 versus 28.6 months (p = 0.005) and 11.0 versus 17.4 months (p = 0.011) in patients with EPE+ versus EPE−, and were 18.7 versus 25.4 months (p = 0.021) and 10.7 versus 14.6 months (p = 0.020) in those with sSVZCC+ versus sSVZCC−. The EPD rates for tumors with EPE−/sSVZCC−, EPE−/sSVZCC+, EPE+/sSVZCC−, and EPE+/sSVZCC+ were 2.8%, 7.1%, 37.0%, and 71.9%, respectively. In EPE+/sSVZCC+, tumor migration was associated with the PE extending along the corpus callosum (77.8%) and subventricular zone (50.0%). ConclusionsOur results support the need for developing individualized irradiation strategies for glioblastomas according to EPE and sSVZCC.

A cognitive hypothesis of the development of differentiative cortical inhibition in humans

Positive and inhibitory conditioning stimuli (Go/NoGo) were presented to healthy adults (n = 35) in an experimental setting for angry face recognition with short intervals between the setting (face), conditioning, and triggering stimuli. A modification of the previously used experimental conditions that consisted in a reduction of the duration of the interstimulus intervals promoted an increase in attitude flexibility (expansion of the group of subjects that made no identification errors at the stage of set testing). The improvement of cognitive performance was accompanied by expansion of the zone of α-oscillation synchronization induced by the NoGo inhibitory conditioning stimulus. Synchronization of α-oscillations was less pronounced in subjects with a rigid cognitive set. Thus, the cognitive hypothesis of cortical inhibition (termed “internal inhibition” by I.P. Pavlov) has been confirmed. The concept of the emergence of top-down inhibitory effects in the prefrontal cortex, implicit internal representation, and selective modulation of attention is discussed.

Synchronization investigation of vibration system of two co-rotating rotor with energy balance method

The key technology of vibrating screens’ design is how to ascertain the synchronous state of vibrating systems. The occurrence of synchronization of a model, two co-rotating rotors fast excited by induction motors installed in a vibrating body, is treated in this article. The synchronization condition and stability criterion of the system are first derived by the energy balance method. The synchronization zones and stable phase difference are then estimated by the two co-rotating rotors operated in synchronous state. Moreover, the energy balance mechanism of the system is explained. The transfer of energy between the rotors by the vibrating body is presented as well. Finally, numerical studies of the dynamics are performed by Runge–Kutta method to verify the theoretical analysis. The results indicated that the synchronous state of the vibrating system is mainly determined by installation distance coefficient rl, installation angular β, symmetric coefficient δ, and electromagnetic torque Tei, but little influenced by mass ratios η and rm.

Hybrid State Estimation Model Based on PMU and SCADA Measurements

Abstract: In this paper, a new method of hybrid non-linear state estimation with PMU and SCADA measurements will be proposed. PMU measurements, the voltage and current phasors, are used for real time transmission line parameters (impedance and admittance) calculation. Transmission line parameters are input data for the conventional state estimator. Calculated parameters of the transmission lines based on the real time PMU measurements are compared with the measured impedance and admittance. The simulation results were carried out on 400 kV Croatian power system. An index of accuracy is set and used to quantify the impact of PMU measurements on power system state estimation by using proposed hybrid model. Software for the proposed hybrid model was developed and it is compatible with PMUs form different vendors. This research was made possible by implementation of 5 PMUs and restoration of wide area monitoring (WAM) system in Croatian power system. Those PMUs were implemented during the reconnection process - reintegration of the 1 st and 2 nd UCTE synchronous zone.

Adverse prognosis and distinct progression patterns after concurrent chemoradiotherapy for glioblastoma with synchronous subventricular zone and corpus callosum invasion

Background and purposeThe subventricular zone (SVZ) and the corpus callosum (CC) invasion status are separately associated with adverse prognosis for glioblastoma. We investigated the prognosis and progression patterns of glioblastoma with and without synchronous SVZ and CC (sSVZCC) invasion. Material and methodsGlioblastoma patients completing concurrent chemoradiotherapy with temozolomide were retrospectively categorized by the preoperative sSVZCC invasion status. The associations between sSVZCC invasion and the survival and progression patterns were analyzed. ResultsIn total, 108 patients, including 36 with sSVZCC invasion, were followed for a median period of 60.2 (range 34.2–86.3) months. The median overall survival (OS) of patients with and without sSVZCC were 18.6 and 26.4months, respectively (p=0.005). Using multivariate analyses with the factors of age, performance, surgery extent, and tumor size, sSVZCC invasion remained significant for a poor OS (hazard ratio, 1.96; 95% confidence interval, 1.19–3.21). The rates of progression at tumor bed, preoperative edematous areas, bilateral hemispheres, and ventricles for tumors with and without sSVZCC invasion were 75% and 63.9% (p=0.282), 41.7% and 9.7% (p<0.001), 47.2% and 13.9% (p<0.001), and 38.9% and 13.9% (p=0.006), respectively. ConclusionsThe sSVZCC invasion status determined the distinct prognosis and progression areas of glioblastoma, which suggests individualized radiotherapy and drug administration strategies.

Transform margin Maastrichtian-Paleogene magmatism in East Asia: The problem of “belts” in the Koryak-Western Kamchatka region

The paper presents data on the specifics of continental-margin magmatism in pull-apart structures at the Cretaceous-Paleogene boundary and discusses the sources of this magmatism, which were produced when the Asian-Pacific transform boundary was formed in place of the Cretaceous convergent boundary. The continental margin was thereby broken by strike-slip and down-dip-strike-slip faults, which formed the East Asian Rift System (EARS). The system induced transform magmatism of two complexes: (i) late Campanian-Eocene weakly differentiated basaltoids (transform boundary basalts, TBB) and (ii) Eocene-Oligocene complexes of acidic rocks (transform boundary acidic rocks, TBA). Similar to plateau basalts, the former complex was produced by fissure eruptions and occurs as extensive areas of volcanic rocks and shield volcanoes, while the latter complex comprises central volcanic edifices crowned with calderas. The specifics of the TBB volcanics is their multicomponent composition: along with dominant OIB-WPB features, they display MORB and IAB signatures (in the absence of a synchronous subduction zone). Isotopic-geochemical and seismic-tomography evidence testifies that the rocks were produced by melts of three types: lower mantle upwelling material that interacted with the asthenosphere and/or fragments of depleted oceanic mantle and with lithospheric domains of the Asian continental margin that had suffered multistage reworking in suprasubduction environments. The isotopic-geochemical features of the acidic TBA rocks, which were formed after (or locally, simultaneously with) the TBB basaltoids, suggest their crustal genesis. The anatexis of the continental margin was triggered by the transition from an extensional to compressional environment (because of mid-Eocene subduction from the ocean) and lag of the mantle magmatic front, which maintained a higher temperature regime. The geodynamic conditions in which the plateau basalts were generated in the extensional zones on continental margins (in East Asia) and in the within-plate environment itself (in the central Arctic) were different.

Cross-frequency synchronization of oscillators with time-delayed coupling.

We carry out theoretical and experimental studies of cross-frequency synchronization of two pulse oscillators with time-delayed coupling. In the theoretical part of the paper we utilize the concept of phase resetting curves and analyze the system dynamics in the case of weak coupling. We construct a Poincaré map and obtain the synchronization zones in the parameter space for m:n synchronization. To challenge the theoretical results we designed an electronic circuit implementing the coupled oscillators and studied its dynamics experimentally. We show that the developed theory predicts dynamical properties of the realistic system, including location of the synchronization zones and bifurcations inside them.

Multi-Attribute Partitioning of Power Networks Based on Electrical Distance

Identifying coherent sub-graphs in networks is important in many applications. In power systems, large systems are divided into areas and zones to aid in planning and control applications. But not every partitioning is equally good for all applications; different applications have different goals, or attributes, against which solutions should be evaluated. This paper presents a hybrid method that combines a conventional graph partitioning algorithm with an evolutionary algorithm to partition a power network to optimize a multi-attribute objective function based on electrical distances, cluster sizes, the number of clusters, and cluster connectedness. Results for the IEEE RTS-96 show that clusters produced by this method can be used to identify buses with dynamically coherent voltage angles, without the need for dynamic simulation. Application of the method to the IEEE 118-bus and a 2383-bus case indicates that when a network is well partitioned into zones, intra-zone transactions have less impact on power flows outside of the zone; i.e., good partitioning reduces loop flows. This property is particularly useful for power system applications where ensuring deliverability is important, such as transmission planning or determination of synchronous reserve zones.

Time-Space Diagram Analysis of Urged Acceleration CA Model

Based on the SDNS cellular automaton (CA) traffic model, an improved single lane traffic CA model with considering the urged acceleration and safe deceleration was proposed. The model not only simulated the interaction between vehicles, but also reproduced nonlinear phenomena which tallies with real traffic such as the synchronism flow and the metastable state. The time-space diagram of new model shows a gray synchronous band zone rather than that black blocking band zone. The range of synchronization is smaller when ps is bigger, urging has less function, congestion area is wider. Comparing with SDNS model, with the proposed model in this paper, when emerging congestion, the combined action of urging and safe deceleration enabled system self-adjustment so that efficiently mitigated congestion.

Self-oscillations of a third order PLL in periodic and chaotic mode and its tracking in a slave PLL

The dynamics of a third order phase locked loop (PLL) with a resonant low pass filter (LPF) has been studied numerically in the parameter space of the system. The range of stable synchronous operating zone of the PLL, expressed in terms of system and signal parameters, is estimated. The obtained results are in agreement with the analytically predicted results in the literature. The PLL dynamics in the unstable region is found to have a sequence of period doubling bifurcation and chaos. In the master–slave mode of operation of two 3rd order PLLs, the slave PLL can track the periodic as well as chaotic dynamics of the master PLL for a narrow range of effective frequency offset when other design parameters are within the stable zone as predicted for an isolated PLL. The synchronization of the master and slave PLLs in this condition is proved to be a generalized one using the auxiliary slave system approach. Experimental observations on prototype hardware circuits for an isolated PLL and for a master–slave PLL arrangement are also given.