Adaptive digital distance protection for series compensated transmission lines

Series capacitors offer considerable technical and economical advantages in long distance a. c. transmission. In particular, their excellent reliability and minimal maintenance requirements make series compensation the most cost effective method of enhancing the power transfer capability of an existing or proposed interconnection. E. H. V. lines employing series capacitors however, pose difficult problems for the line protection relays, not encountered with plain feeders. One important cause of these problems is the resonance between the series capacitor and the line series inductance, which in turn imposes a sub-synchronous oscillation on the system signals. Also, the rapid changes in the circuit parameters, resulting from the operation of the capacitor protection equipment, namely the spark gaps, introduce some difficulties for the line protection schemes, especially an impedance measuring relay. These spark gaps are installed in parallel with the series capacitors to prevent the development of very high voltages across the capacitor which could cause excessive damage to the equipment. The work presented herein describes a new digital distance relay suitable for series compensated line applications. The errors in the impedance measurement for a phase to earth fault when the spark gaps do not flash over, are discussed and new methods are proposed to compensate for these errors. The new concept of a complex residual compensation factor, as opposed to a real one, is also discussed. A new adaptive filtering is incorporated in the relay in order to minimise the detrimental effect of the subsynchronous oscillation on the relay decision logic. Finally, the relay is thoroughly tested for many different system configurations, to fully evaluate the relay response

Formal Modeling and Analysis of Mobile Ad hoc Networks

Fokkink, W.J. [Promotor]Luttik, S.P. [Copromotor

C3G mediated suppression of malignant transformation involves activation of PP2A phosphatases at the subcortical actin cytoskeleton

In previous work, we demonstrated that C3G suppresses Ras oncogenic transformation by a mechanism involving inhibition of ERK phosphorylation. Here we present evidences indicating that this suppression mechanism is mediated, at least in part, by serine/threonine phosphatases of the PP2A family. Thus: (i) ectopic expression of C3G or C3GΔCat (mutant lacking the GEF activity) increases specific ERK-associated PP2A phosphatase activities; (ii) C3G and PP2A interact, as demonstrated by immunofluorescence and co-immunoprecipitation experiments; (iii) association between PP2A and MEK or ERK increases in C3G overexpressing cells; (iv) phosphorylated-inactive PP2A level decreases in C3G expressing clones and, most importantly, (v) okadaic acid reverts the inhibitory effect of C3G on ERK phosphorylation. Moreover, C3G interacts with Ksr-1, a scaffold protein of the Ras-ERK pathway that also associates with PP2A. The fraction of C3G involved in transformation suppression is restricted to the subcortical actin cytoskeleton where it interacts with actin. Furthermore, the association between C3G and PP2A remains stable even after cytoskeleton disruption with cytochalasin D, suggesting that the three proteins form a complex at this subcellular compartment. Finally, C3G- and C3GΔCat-mediated inhibition of ERK phosphorylation is reverted by incubation with cytochalasin D. We hypothesize that C3G triggers PP2A activation and binding to MEK and ERK at the subcortical actin cytoskeleton, thus favouring ERK dephosphorylation. © 2007 Elsevier Inc. All rights reserved.This work was supported by grants SAF2003-04177 andGEN2003- 20239-C06-02 from MEC, Spain, FIS-FEDERPI030651, PI041324 and PI061274 from ISCIII,MSC, Spain, as well as institutional support from Redes Temáticas (C03/10 and RD06/0020/0000) de investigación en cáncer from ISCIII, MSC, Spain. S. M-E is a postodoctoral fellow supported by grant GEN2003-20239-C06-02. C.G. was supported by the Ramón y Cajal Program from the Spanish Ministry of Education.Peer Reviewe

A Process Calculus for Dynamic Networks

In this paper we propose a process calculus framework for dynamic networks in which the network topology may change as computation proceeds. The proposed calculus allows one to abstract away from neighborhood-discovery computations and it contains features for broadcasting at multiple transmission ranges and for viewing networks at different levels of abstraction. We develop a theory of confluence for the calculus and we use the machinery developed towards the verification of a leader-election algorithm for mobile ad hoc networks

Determining a piston's top dead center (TDC) in an automobile using installed piezoelectric on a vibrating beam

Smart structures and MEMS are considered important field recently, due to the importance and high capabilities in measurement and the power of reaction and response to changes of the surroundings. This research concerns two fields of practical vision in the automotive industry and discuss the energy recycled industrial vibrations. The goal is to use the PVDF piezoelectric elements in car flywheel for energy harvesting, and compare and replace it with the revolution sensor. This research is totally based on empirical tests data and the result that the use of piezoelectric polymer sensors can harvest energy, was find performing far better than inductive sensors.Keywords: Piezoelectric element; Vibration energy harvesting; smart structures; Revolution sensor; Flywhee

Ophthalmic manifestations of congenital protein C deficiency: A case report and mini review

Background: Homozygous protein C (PC) deficiency is a potentially fatal disease with ocular blinding presentation or sequela. Case presentation: A 5 month-old boy was presented for evaluation of leukocoria. He had a history of frequent bruises and PC deficiency, treated with warfarin. His intraocular pressure was normal. In the left eye leukoma with anterior segment dysgenesis, shallow anterior chamber, and cataract were observed. Fundus was not visible. B-scan revealed a closed funnel retinal detachment. His right eye had a normal anterior segment and a thin retina with anomalous retinal vascular branching at equator and peripheral retina. A fibrovascular tuft on the optic nerve head with induced traction on superior arcade was visible. Total loss of a and b wave of both were appreciated in electroretinography (ERG). Fluorescein angiography (FA) showed very severe leakage at the junction of the vascularized and non-vascularized retina and optic nerve head. Favorable outcome was achieved with lasering of avascular retina in the right eye. Conclusion: The potential for protein C deficiency should be assessed in all infants with leukocoria, anterior segment dysgenesis, retinal detachment and retinal dysplasia. Early diagnosis could save the child's life and vision. © 2020 The Author(s)

Petrology, geochemistry and tectonomagmatic evolution of Hezar Igneous Complex (Rayen - south of Kerman - Iran): the first description of an arc remnant of the Neotethyan subduction zone

The Hezar Igneous Complex (HIC) in the south-eastern part of Urumieh-Dokhtar magmatic arc, is the most prominent magmatic feature in the Kerman Porphyry Copper Belt, that understanding magmatic evolution of which may shed light on the tectonomagmatic development of this less-studied part of an important magmatic arc in the Neotethys realm. The HIC has been developed in the the intersection of the N-S striking Sabzevaran fault and the NW-SE striking Rafsanjan-Rayen fault. It is indicated that the possible place of the conduit and vent is in Jalas Mountain which has been splitted later by the Sabzevaran fault into Minor and Major Jalas. The current summit had been constructed by ascending magma chamber under the HIC that constitutes the Kamali Mountain at the south of the summit. Some plutonic rocks of the HIC are exposed at Kamali Mountain. The subalkaline rocks of this complex mainly are composed of different pyroclastic and lava flow rocks, acidic to basic in composition, showing the evidences of fractional crystallization and mineral segregation. Sequential explosive and effusive eruptions with Strombolian to Vulcanian types are evident in the successive volcanic layers. The compositional trend shows the melting of spinel lherzolite, not garnet lherzolite. The subduction-related mechanism of the magma genesis has been indicated by IAB nature of the magma formation in geochemical diagrams.publishe

Equational reasoning on ad hoc networks

Abstract. We provide an equational theory for Restricted Broadcast Process Theory to reason about ad hoc networks. We exploit an extended algebra called Computed Network Theory to axiomatize restricted broadcast. It allows one to define an ad hoc network with respect to the underlying topologies. We give a sound and complete axiomatization for the recursion-free part of the term algebra CNT, modulo what we call rooted branching computed network bisimilarity.

Emotional Face Perception in Patients with Schizophrenia: an Event-Related Potential Study

Emotional face recognition has been shown to be drastically impaired among patients with schizophrenia. Since the underlying processes of this deficit have not been widely addressed, we attempted to investigate the relationship between facial expression perception and clinical symptoms in patients with schizophrenia. We enrolled 28 patients with schizophrenia and 28 healthy adults matched by their sex and age. The amplitude and latency of component N170 in event-related EEG potentials (ERPs) induced by presentations of happy, fearful, and neutral face images were comparatively evaluated in these two groups. Furthermore, the relationship between the N170 measures and clinical symptoms of schizophrenia were assessed using the Positive and Negative Syndrome Scale (PANSS). The N170 responses to facial expressions in patients with schizophrenia were significantly delayed, as compared to healthy control participants [F (1, 54) = 4.25, P = 0.044]. The N170 response to fearful faces (as compared to happy and neutral faces) was elicited with the minimum latency in the control group, while this component was most delayed among schizophrenics. Positive schizophrenia symptoms correlated with the amplitudes of the left-hemisphere N170 component in response to happy, fearful, and neutral faces. Our findings suggest that the facial expression deficit in schizophrenia is related to delayed responses in face perception and is influenced by the severity of positive symptoms. The evident delay in fearful face perception among patients with schizophrenia may partly explain their inappropriate reactions to threatening conditions.У пацієнтів, котрі страждають на шизофренію, розпізнавання виразів обличчя є серйозно порушеним. Оскільки процеси, що зумовлюють подібний дефіцит, вивчені недостатньо, ми намагалися дослідити співвідношення сприйняття виразів обличчя та клінічних симптомів у пацієнтів із цим захворюванням. В обстежувану групу ввійшли 28 пацієнтів із діагнозом шизофренія та 28 дорослих суб’єктів; групи були узгоджені в статевому та віковому аспектах. У представників цих двох груп вимірювали та порівнювали амплітуду й латентний період компонента N170 у складі пов’язаних з подією потенціалів, викликаних пред’явленням зображень облич зі щасливим, переляканим і нейтральним виразом. Потім оцінювали взаємозв’язок параметрів N170 з оцінками клінічних симптомів шизофренії згідно зі шкалою позитивних і негативних синдромів (PANSS). Розвиток компонента N170 після пред’явлення зображень облич з різними виразами відбувався у пацієнтів із шизофренією істотно пізніше, ніж у здорових контрольних суб’єктів [F (1, 54) = = 4.25, P = 0.044]. N170 після пред’явлення переляканих облич (порівняно зі щасливими та нейтральними) розвивався у суб’єктів контрольної групи з мінімальною затримкою, а у шизофреників він виникав значно пізніше. Інтенсивність позитивних симптомів у шизофреників корелювала з амплітудами N170 у лівій півкулі після пред’явлення як щасливих, так і переляканих і нейтральних облич. Наші спостереження показують, що дефектність сприйняття виразу обличчя у пацієнтів, хворих на шизофренію, пов’язана із затримкою відповідей ЦНС, і на таку дефектність впливає тяжкість позитивних симптомів. Очевидна затримка сприйняття облич з переляканим виразом у пацієнтів із шизофренією може частково пояснювати неадекватність їх реакцій на загрозливі ситуації