Initial Characterized L-spaces and Characterized L- topological Groups

In this research work, new topological notions are proposed and investigated. The notions are named initial characterized L-spaces and characterized L-topological groups. The properties of such notions are deeply studied. We show that the intitial characterized L-space for an characterized L-spaces exists. By this notion, the notions of characterized L-subspace and characterized product L-space are introduced and studied. More information can be found in the full paper

On Initial and Final Characterized L- topological Groups

In this research work, new topological notions are proposed and investigated. The notions are named finalcharacterized L-spaces and initial and final characterized L-topological groups. The properties of such notionsare deeply studied. We show that all the final lefts and all the final characterized L-spaces are uniquely exist inthe category CRL-Sp and hence CRL-Sp is topological category over the category SET of all sets. By the notion offinal characterized L-space, the notions of characterized qoutien pre L-spaces and characterized sum L-spacesare introduced and studied. The characterized L-subspaces together with their related inclusion mappings andthe characterized quotient pre L-spaces together with their related canonical surjections are the equalizers andco-equalizers, respectively in CRL-Sp. Moreover, we show that the initial and final lefts and then the initial andfinal characterized L-topological groups uniquely exist in the category CRL-TopGrp. Hence, the category CRLTopGrpis topological category over the category Grp of all groups. By the notion of initial and finalcharacterized L-topological groups, the notions of characterized L-subgroups, characterized product Ltopologicalgroups and characterized L-topological quotient groups are introduced and studied., we show that thecategory CRL-TopGrp is concrete and co-concrete category of the category L-Top. More details can be found in the full paper

New Techniques for Disconnector Switching VFT Mitigation in GIS

Switching operations in a Gas Insulated Substations (GIS) generate very fast transient over voltages (VFTO) which are dangerous for the transformer and the system insulation because of their short rise time. Under special circumstances the overvoltages can arise close to the transformer Basic Insulation Level (BIL). The reduction of VFTO amplitudes is considered main challenges. Therefore, VFTO in the 220 kV Wadi-Hoff GIS is analyzed and the worst case for disconnector switching is predicted using EMTP/ATP in this paper. VFTO mitigation techniques are studied in this work. Furthermore, proposed techniques are presented for mitigating the VFTO. The proposed techniques can be used by the maintenance engineers, transformer designers, and GIS insulation manufactures. The results show that the proposed techniques highly reduce the VFTO in a simple manner.DOI:http://dx.doi.org/10.11591/ijece.v4i2.518

Correlation between Paris function parameters to crack velocity for Alumina ceramics

The question about the existence of correlation between the parameters A and m of the Paris function is re-examined theoretically for brittle material such as alumina ceramic (Al2O3) with different grain size. Investigation about existence of the exponential function which fit a good approximation to the majority of experimental data of crack velocity versus stress intensity factor diagram. The rate theory of crack growth was applied for data of alumina ceramics samples in region I and making use of the values of the exponential function parameters the crack growth rate theory parameters were estimated

Mitigation of Lightning Hazards at the More Sensitive Points in Wind Farms Using Ant-Colony Optimization Technique

The lightning energy can be very harmfull to the wind turbine farm components. This paper attempts to evaluate the overvoltages at the sensitive points in wind farm, using ATP-EMTP package program. Four cases were performed; a) the transient voltage distribution in the insulating layer of the control line, b) the transient voltage on the control equipment, c) the coupling voltage between the tower and the control, and, d) the transient voltage distribution in the wind turbine WT generator, boast transformers and grid. These cases were performed under different lightning current conditions and at conventional design and proper design of grounding system. The results show that the ground potential rise (GPR) is reduced with using the proper design of wind turbine ground system, but the induced voltage at the control system will not affected. This work determines the optimum location of wind turbine at the areas of maximum lightning incidence. Ant colony optimization (ACO) technique is implemented to find the optimum wind farm location. This work enhances the protection strategy of the wind farms against lightning stroke

Reactions with 5-Arylazo- and 5-Arylidene-4-thiohydantoin Derivatives

5-Arylazo-3-phenyl-4-thiohydantoins (IIa-g) have been prepared and then treated with primary aromatic amines to afford the corresponding 5-arylazo-4-arylimino-3-phenyl hydantoins (VIIa-c). 3-Phenyl-4-thiohydantoin reacted with aromatic aldehydes in the presence of glacial acetic acid and fused sodium acetate to give 5-arylidene-3-phenyl-4-thiohydantoin derivatives (VIIIa-e). In the coloured arylidene derivatives (VIII,a d, e) on treatment with alkyland/ or arylmagnesium halide addition occurs to the exocyclic double bond to give the products (IXa-e). The Grignard product (Xa) was oxidised with a mixture of chromic acid in glacial acetic acid to give phenyl parabanic acid and ethyl phenyl ketone

Mitigation of Lightning Hazards at the More Sensitive Points in Wind Farms Using Ant-Colony Optimization Technique

The lightning energy can be very harmfull to the wind turbine farm components. This paper attempts to evaluate the overvoltages at the sensitive points in wind farm, using ATP-EMTP package program. Four cases were performed; a) the transient voltage distribution in the insulating layer of the control line, b) the transient voltage on the control equipment, c) the coupling voltage between the tower and the control, and, d) the transient voltage distribution in the wind turbine WT generator, boast transformers and grid. These cases were performed under different lightning current conditions and at conventional design and proper design of grounding system. The results show that the ground potential rise (GPR) is reduced with using the proper design of wind turbine ground system, but the induced voltage at the control system will not affected. This work determines the optimum location of wind turbine at the areas of maximum lightning incidence. Ant colony optimization (ACO) technique is implemented to find the optimum wind farm location. This work enhances the protection strategy of the wind farms against lightning stroke

OPTIMAL DISTRIBUTED CONTROL OF STOCHASTIC ELLIPTIC SYSTEMS WITH CONSTRAINTS

The objective of this paper is to study the optimality for stochastic non cooperative elliptic systems. A distributed control problem for a stochastic elliptic systems with constraints on states and controls is studied. First, the existence and uniqueness of the state process for these systems are proved. The necessary and sufficient conditions of optimality are derived for the Dirichlet and Neumann problems

Fuzzy soft separation axioms in fuzzy soft topological spaces.

Fuzzy soft separation axioms was introduced by Mahanta and Das ([5]) using the definitions of a `fuzzy soft point' and `the complement of a fuzzy soft point is a fuzzy soft point', and `distinct of fuzzy soft points' in there sense.  In this paper we, introduce fuzzy soft separation axioms in terms of the modified definitions of a `fuzzy soft point', the complement of a fuzzy soft point is a fuzzy soft set' and `distinct of fuzzy soft points'([7]). Also, we study some of their properties. Finally, we discuss fuzzy soft topological property for such spaces.                                                          &nbsp

EFFECT OF VARIABLE WATER APPLICATION RATES ON YIELD OF FLAX AND IRRIGATION WATER USE EFFICIENCY

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