Built heritage management systems : the framework of a digital tool for the conservation of Brisbane City Hall

Brisbane City Hall (BCH) is arguably one of Brisbane’s most notable and iconic buildings. Serving as the public’s central civic and municipal building since 1930, the importance of this heritage listed building to cultural significance and identity is unquestionable. This attribute is reflected within the local government, with a simplified image of the halls main portico entrance supplying Brisbane City Council with its insignia and trademark signifier. Regardless of these qualities, this building has been neglected in a number of ways, primarily in the physical sense with built materials, but also, and just as importantly, through inaccurate and undocumented works. Numerous restoration and renovation works have been undertaken throughout BCH’s lifetime, however the records of these amendments are far and few between. Between 2010 and 2013, BCH underwent major restoration works, the largest production project undertaken on the building since its initial construction. Just prior to this conservation process, the full extent of the buildings deterioration was identified, much of which there was little to no original documentation of. This has led to a number of issues pertaining to what investigators expected to find within the building, versus what was uncovered (the unexpected), which have resulted directly from this lack of data. This absence of record keeping is the key factor that has contributed to the decay and unknown deficiencies that had amassed within BCH. Accordingly, this raises a debate about the methods of record keeping, and the need for a more advanced process that is able to be integrated within architectural and engineering programs, whilst still maintaining the ability to act as a standalone database. The immediate objective of this research is to investigate the restoration process of BCH, with focus on the auditorium, to evaluate possible strategies to record and manage data connected to building pathology so that a framework can be developed for a digital heritage management system. The framework produced for this digital tool will enable dynamic uses of a centralised database and aims to reduce the significant data loss. Following an in-depth analysis of this framework, it can be concluded that the implementation of the suggested digital tool would directly benefit BCH, and could ultimately be incorporated into a number of heritage related built form.

A motor controller using field oriented control and Hall effect rotor position sensors : simulation and implementation

A field oriented control (FOC) algorithm is simulated and implemented for use with a permanent magnet synchronous motor (PMSM). Rotor position is sensed using Hall effect switches on the stator because other hardware position sensors attached to the rotor may not be desirable or cost effective for certain applications. This places a limit on the resolution of position sensing – only a few Hall effect switches can be placed. In this simulation, three sensors are used and the position information is obtained at higher resolution by estimating it from the rotor dynamics, as shown in literature previously. This study compares the performance of the method with an incremental encoder using simulations. The FOC algorithm is implemented using Digital Motor Control (DMC) and IQ Texas Instruments libraries from a Simulink toolbox called Embedded Coder, and downloaded into a TI microcontroller (TMS320F28335) known as the Piccolo via Code Composer Studio (CCS).

Group 14 element-based non-centrosymmetric quantum spin hall insulators with large bulk gap

To date, a number of two-dimensional (2D) topological insulators (TIs) have been realized in Group 14 elemental honeycomb lattices, but all are inversionsymmetric. Here, based on first-principles calculations, we predict a new family of 2D inversion-asymmetric TIs with sizeable bulk gaps from 105 meV to 284 meV, in X2–GeSn (X = H, F, Cl, Br, I) monolayers, making them in principle suitable for room-temperature applications. The nontrivial topological characteristics of inverted band orders are identified in pristine X2–GeSn with X = (F, Cl, Br, I), whereas H2–GeSn undergoes a nontrivial band inversion at 8% lattice expansion. Topologically protected edge states are identified in X2–GeSn with X = (F, Cl, Br, I), as well as in strained H2–GeSn. More importantly, the edges of these systems, which exhibit single-Dirac-cone characteristics located exactly in the middle of their bulk band gaps, are ideal for dissipationless transport. Thus, Group 14 elemental honeycomb lattices provide a fascinating playground for the manipulation of quantum states.

Probing the Neutral Edge Modes in Transport across a Point Contact via Thermal Effects in the Read-Rezayi Non-Abelian Quantum Hall States

Non-Abelian quantum Hall states are characterized by the simultaneous appearance of charge and neutral gapless edge modes, with the structure of the latter being intricately related to the existence of bulk quasiparticle excitations obeying non-Abelian statistics. Here we propose a scenario for detecting the neutral modes by having two point contacts in series separated by a distance set by the thermal equilibration length of the charge mode. We show that by using the first point contact as a heating device, the excess charge noise measured at the second point contact carries a nontrivial signature of the presence of the neutral mode. We also obtain explicit expressions for the thermal conductance and corresponding Lorentz number for transport across a quantum point contact between two edges held at different temperatures and chemical potentials.

Prediction of a large-gap quantum-spin-Hall insulator: Diamond-like GaBi bilayer

A quantum-spin-Hall (QSH) state was achieved experimentally, albeit at a low critical temperature because of the narrow band gap of the bulk material. Twodimensional topological insulators are critically important for realizing novel topological applications. Using density functional theory (DFT), we demonstrated that hydrogenated GaBi bilayers (HGaBi) form a stable topological insulator with a large nontrivial band gap of 0.320 eV, based on the state-of-the-art hybrid functional method, which is implementable for achieving QSH states at room temperature. The nontrivial topological property of the HGaBi lattice can also be confirmed from the appearance of gapless edge states in the nanoribbon structure. Our results provide a versatile platform for hosting nontrivial topological states usable for important nanoelectronic device applications.

Effect of inter-edge Coulomb interactions on transport through a point contact in nu=5/2 quantum Hall state

We study transport across a point contact separating two line junctions in a nu = 5/2 quantum Hall system. We analyze the effect of inter-edge Coulomb interactions between the chiral bosonic edge modes of the half-filled Landau level (assuming a Pfaffian wave function for the half-filled state) and of the two fully filled Landau levels. In the presence of inter-edge Coulomb interactions between all the six edges participating in the line junction, we show that the stable fixed point corresponds to a point contact that is neither fully opaque nor fully transparent. Remarkably, this fixed point represents a situation where the half-filled level is fully transmitting, while the two filled levels are completely backscattered; hence the fixed point Hall conductance is given by G(H) = 1/2e(2)/h. We predict the non-universal temperature power laws by which the system approaches the stable fixed point from the two unstable fixed points corresponding to the fully connected case (G(H) = 5/2e(2)/h) and the fully disconnected case (G(H) = 0).

En sjukdom af högst elakt släckte : Återfallsfebern på Sveaborg och i Karlskrona 1788-1790

Sommaren 1788 drabbades den svenska flottan av en svårartad febersjukdom. Febern, som senare definierats som febris recurrens el. återfallsfeber, hade sitt ursprung i den ryska flottan. Besättningen ombord skeppet Vladislav, krigsbytet från slaget vid Hogland, bar på ett stort antal smittade klädlöss. Efter flottans ankomst till Sveaborg spred sig sjukdomen snabbt bland manskapet, men även bland fästningens garnison. Förhållandena inom militären, både inom lantarmén och framför allt inom flottan, var gynnsamma för epidemiers spridning. De trånga utrymmena, den ensidiga kosten, det undermåliga dricksvattnet, den bristande hygienen: allt gynnade uppkomsten och spridningen av olika epidemier. Manskapets försämrade allmäntillstånd gjorde, att sjukdomarna blev mera förödande än vad de i andra förhållanden skulle ha varit. Bristen på manskap och material under Gustav III:s ryska krig var enormt, bl.a. var bristen på medicinsk personal och -utrustning skriande. Då flottan och armén drabbades av en epidemi av katastrofala dimensioner stod myndigheterna hjälplösa. Epidemin visaqr tydligt hur illa förberett hela kriget var och hur misskött flottans sjukvård var. På Sveaborg var förhållandena fruktansvärda. Halva garnisonen uppges ha avlidit, och det låg travar av lik överallt. Kaserner m.fl. byggnader adapterades till provisoriska lasarett och det rådde brist på allt. De medicinska myndigheterna representerades av den till fästningen skickade andra fältläkaren, som tillsammans med läkarna på fästningen gjorde sitt bästa i enlighet med tidens vårdmetoder. Då den svenska örlogsflottan i november seglat över tilll Karlskrona spred sig epidemin i staden. Sjukdomen grasserade också bland de civila. Då sjukdomens orsak och utbredningssätt var okända, kunde man varken hindra epidemin från att spridas eller genomföra adekvata vårdmetoder. Tvärtom, med de hemförlovade båtsmännen spred sig sjukdomen även till de övriga delarna av riket. Under 1789 var flottan p.g.a. de många sjukdomsfallen närmast operationsoduglig. Under vårvintern och våren 1790 avtog epidemin. Epidemin var ett svårt medicinskt problem. För att utreda situationen i Karlskrona skickade den tillförordnade regeringen, utredningskommissionen och Collegium medicum sina egna representanter till staden. De olika läkarnas sjukdomssyner grundade sig främst på tron om sjukdomars uppkomst genom miasma och förbättrandet av luftkvaliteten sågs som en väsentlig vårdform. I arbetet jämförs de olika myndigheternas och några av de på platsen varande läkarnas syn på sjukdomens art, dess orsaker och ursprung. De flesta härleder sjukdomen till den ryska flottan, och nämner någon form av smitta. Som främsta sjukdomsorsak nämns dock miasma och de rekommenderade vårdformerna representerade den humoralpatologiska synen. Förste amiralitetsläkaren Arvid Faxe representerar dock en annan åsikt, i det att han enbart tror på sjukdomens överföring via smitta. Epidemin var också ett politiskt problem. Epidemin var en lokal angelägenhet ända till dess att flottans operationer hämmades av manskapsbristen, varefter den blev ett ärende på högsta nivå. Kungen ingrep sommaren 1789 genom att grunda en kommision med rätt vidsträckta befogenheter. I Karlskrona verkar de militära myndigheterna och läkarna ha misstrott och skuldsatt varandra för katastrofen, och förhållandet mellan de till staden sända utredarna och militärerna var likaså inflammerat. Genom källorna återspeglas rivalitet, avund och inbördes konkurrens. Personalbristen var svår, och den skyldiga söktes utanför den egna kretsen. Den danskfödde apotekaren med sina påstott otjänliga mediciner blev en ypperlig syndabock. Örlogsflottan beräknas i sjukdomar ha förlorat omkring 10.000 man i döda, huvudsakligen i Karlskrona (civila inberäknade). Armén och Skärgårdsflottan uppges likadeles ha mist omkring 10.000 man, medan antalet i strid stupade armésoldater endast var ca 1500. Sammanlagt antas alltså ca 20.000 människor ha mist livet; både i återfallsfeber, men även i andra, samtidigt grasserande farsoter. I denna siffra är inte de övriga delarna av riket inberäknade. Epidemin i fråga kan alltså på goda grunder anses vara det svenska 1700-talets största medicinska katastrof.

Theory For The Anomalous Hall Constant Of Mixed-Valence Systems

We show that the large anomalous Hall constants of mixed-valence and Kondo-lattice systems can be understood in terms of a simple resonant-level Fermi-liquid model. Splitting of a narrow, orbitally unquenched, spin-orbit split, f resonance in a magnetic field leads to strong skew scattering of band electrons. We interpret both the anomalous signs and the strong temperature dependence of Hall mobilities in CeCu2Si2, SmB6, and CePd3 in terms of this theory.

Graphical method to include temperature variation of activation energy in Hall data analysis

A graphical method is presented for Hall data analysis, including the temperature variation of activation energy due to screening. This method removes the discrepancies noted in the analysis of recently reported Hall data on Si(In).

Elizabeth Engel nee Benjamin-Rasmussen with her daughter Dorel Hall nee Engel in Elizabeth's home; Silver Springs, Maryland Portraits Family

Digital Image

Elizabeth Engel nee Benjamin-Rasmussen with her daughter Dorel Hall nee Engel in Elizabeth's home; Silver Springs, Maryland Portraits Family

Digital Image

Applicability of the van der Pauw-Hall measurement technique to implanted samples

The application of the van der Pauw-Hall measurement technique to implanted samples in which the mobility varies with depth has still not been fully justified. A proof that the technique is in fact applicable in this situation is given. Journal of Applied Physics is copyrighted by The American Institute of Physics.

AC conductivity of a quantum Hall line junction

We present a microscopic model for calculating the AC conductivity of a finite length line junction made up of two counter-or co-propagating single mode quantum Hall edges with possibly different filling fractions. The effect of density-density interactions and a local tunneling conductance (sigma) between the two edges is considered. Assuming that sigma is independent of the frequency omega, we derive expressions for the AC conductivity as a function of omega, the length of the line junction and other parameters of the system. We reproduce the results of Sen and Agarwal (2008 Phys. Rev. B 78 085430) in the DC limit (omega -> 0), and generalize those results for an interacting system. As a function of omega, the AC conductivity shows significant oscillations if sigma is small; the oscillations become less prominent as sigma increases. A renormalization group analysis shows that the system may be in a metallic or an insulating phase depending on the strength of the interactions. We discuss the experimental implications of this for the behavior of the AC conductivity at low temperatures.

Myer S. Isaacs collection undated, 1844, 1851-1925

Contains correspondence and newspaper clippings relating to the centennial birthday celebration of and memorial services for Sir Moses Montefiore; correspondence consists primarily of replies to a circular advocating the holding of memorial services issued by the Board of Delegates on Civil and Religious Rights from congregations in Buffalo, Charleston, Chicago, Cincinnati, Cleveland, and Detroit. Contains also correspondence relating to the activities of the Alliance Israelite Universelle on behalf of Palestine and the Jews in the Balkan States and Morocco and to the establishment of United States committees for the Alliance and the raising of funds, including correspondence with H. Pereira Mendes, Henry S. Jacobs, John Hay, and Adolphe Cremieux as well as letters from Baltimore, Cleveland, Detroit, Galveston, Minneapolis, Mobile, Rochester, St. Louis, and San Francisco. Also contains extensive correspondence concerning anti-semitism in Russia, aid to Jewish immigrants, and Jewish agricultural colonies in the United States, with letters from James G. Blaine, Manuel Augustus Kursheedt, Sabato Morais, Charles Nathan, Hirsch Leib Sabsovich, (Isaac N.?) Seligman and Judah Wechsler, among others. Also contains newspaper clippings and other items relating to Jewish life during the late 19th century and articles and memorabilia about various members of the Isaacs family.