Human Trafficking and Terrorism: Utilizing National Security Resources to Prevent Human Trafficking in the Islamic State

This is a report of a Master’s thesis done in behalf of the local network in Stockholm, under Fortum Distribution AB. The thesis was to conduct a review of a distribution station named Fs Myrängen located in Täby. A model was created for the 11 kV network linked to the secondary side of Fs Myrängen. Based on this model and using symmetrical components, theoretical fault currents (short circuit and ground fault) could be calculated. The results of these fault currents are used to investigate and develop new settings for relay protection and ground equipment in the station. The results of the calculated fault currents were also used to investigate unwanted voltages that occurs for grounded parts due to earth faults. The value of these unwanted voltages was then compared to heavy current regulations developed by the Electrical Safety Authority in Sweden. Another element of the work was to create a rehabilitation plan for the structure on the 11 kV side of Fs Myrängen, the main goal regarding the rehabilitation plan was to investigate the advantages and disadvantages that exist at a possible transition to numerical protection relays. This was done by making a market overview of the different types of numerical protection relays and compare these with the existing analog protective device in Fs Myrängen. The study showed that protective relay settings should be revised according to the recommendations in the report, ground equipment should be replaced with a self-regulating type, transformers should be replaced due to age and capacity limitations. Regarding a switch to numerical protection relays the type REF615 from ABB was recommended, in that case the control board in the station should be replaced to a station computer. Furthermore should current transformers be replaced to recive a desired sensitivity regarding detection of ground faults. The report also showed that Fs Myrängen meets the regulations of unwanted voltages over grounded parts in distribution stations due to earth faults.Detta är en rapport av ett examensarbete utfört i uppdrag av lokalnät Stockholm under Fortum Distribution AB. Examensarbetet gick ut på att göra en översyn av en fördelningsstation vid namn Fs Myrängen som är belägen i Täby. En modell skapades av 11 kV nätet kopplat till Fs Myrängen, utifrån denna modell samt med hjälp av symmetriska komponenter beräknades teoretiska felströmmar både för kortslutning och jordslutning. Resultaten av dessa felströmmar användes för att utreda och ta fram inställningar på reläskydd och nollpunktsutrustning i stationen. Resultaten på framräknade jordfelsströmmar användes även för att utreda vilken spänningssättning som uppstår vid jordfel, i de nätstationer som matas av Fs Myrängen. Spänningssättningen på nätstationerna jämfördes sedan med de starkströmsföreskrifter som är framtagna av elsäkerhetsverket. Ett annat moment i arbetet var att skapa en upprustningsplan för skyddsanordningen på 11 kV sidan i Fs Myrängen, huvudmålet för den biten var att utreda vilka fördelar och nackdelar som finns vid en eventuell övergång till numeriska skydd. Detta gjordes genom att göra en marknadsöversikt över olika typer av numeriska reläskydd, samt jämföra dessa med den befintliga skyddsanordningen i Myrängen som är av analog typ. Studien visade att reläskyddsinställningar bör ses över enligt rekommendationer i rapporten, nollpunktsutrustningen bör bytas ut till självreglerande typ, transformatorerna bör bytas ut p.g.a. ålder och kapacitetsbegränsning. Gällande skyddsanordningen rekommenderas en övergång till numeriska skydd av typen REF615, och i samband med detta byta ut den befintliga kontrolltavlan i stationen till en stationsdator. Vidare bör även strömtransformatorer för jordfelsskydden bytas ut för att uppnå önskad känslighet gällande detektering av jordfel. För spänningssättning av nätstationer vid jordfel, visar resultaten att stationen uppfyller kraven enligt starkströmsföreskrifterna från elsäkerhetsverket

Classical Statistics Inherent in a Quantum Density Matrix

A density matrix formulation of classical bipartite correlations is constructed. This leads to an understanding of the appearance of classical statistical correlations intertwined with the quantum correlations as well as a physical underpinning of these correlations. As a byproduct of this analysis, a physical basis of the classical statistical correlations leading to additive entropy in a bipartite system discussed recently by Tsallis et al emerges as inherent classical spin fluctuations. It is found that in this example, the quantum correlations shrink the region of additivity in phase space.Comment: 10 pages, 3 figure

Entanglement and optimal strings of qubits for memory channels

We investigate the problem of enhancement of mutual information by encoding classical data into entangled input states of arbitrary length and show that while there is a threshold memory or correlation parameter beyond which entangled states outperform the separable states, resulting in a higher mutual information, this memory threshold increases toward unity as the length of the string increases. These observations imply that encoding classical data into entangled states may not enhance the classical capacity of quantum channels.Comment: 14 pages, 8 figures, latex, accepted for publication in Physical Review

On the Possibility of Quasi Small-World Nanomaterials

The possibility of materials that are governed by a fixed point related to small world networks is discussed. In particular, large-scale Monte Carlo simulations are performed on Ising ferromagnetic models on two different small-world networks generated from a one-dimensional spin chain. One has the small-world bond strengths independent of the length, and exhibits a finite-temperature phase transition. The other has small-world bonds built from atoms, and although there is no finite-temperature phase transition the system shows a slow power-law change of the effective critical temperature of a finite system as a function of the system size. An outline of a possible synthesis route for quasi small-world nanomaterials is presented.Comment: 13 pages, 9 figures, submitted to Brazilian Journal of Physics, conference proceedings for III Brazilian Meeting on Simulational Physics (2003

The double life of electrons in magnetic iron pnictides, as revealed by NMR

We present a phenomenological, two-fluid approach to understanding the magnetic excitations in Fe pnictides, in which a paramagnetic fluid with gapless, incoherent particle-hole excitations coexists with an antiferromagnetic fluid with gapped, coherent spin wave excitations. We show that this two-fluid phenomenology provides an excellent quantitative description of NMR data for magnetic "122" pnictides, and argue that it finds a natural justification in LSDA and spin density wave calculations. We further use this phenomenology to estimate the maximum renormalisation of the ordered moment that can follow from low-energy spin fluctuations in Fe pnictides. We find that this is too small to account for the discrepancy between ab intio calculations and neutron scattering measurements.Comment: Accepted for publication in Europhys. Lett. 6 pages, 4 figure