Model of multiphoton transitions in a current-biased Josephson junction

We present a simple model for multiphoton transitions between the quasi-bound states of a current-driven Josephson junction. The transitions are induced by applying an ac voltage with controllable frequency and amplitude across the junction. The voltage induces transitions when the ac frequency equals n times the splitting between the ground and first excited quasi-bound state of the junction. We calculate the transition matrix elements as functions of the dc bias current I, and the frequency and amplitude of the ac voltage, for representative junction parameters. We also calculate the frequency-dependent absorption coefficient by solving the relevant Bloch equations when the ac amplitude is sufficiently small. In this regime, the absorption coefficient is a sum of Lorentzian lines centered at the n-photon absorption frequency, of strength proportional to the squared matrix elements. For fixed ac voltage amplitude, the n-photon transition rate usually decreases with increasing n. We also find a characteristic even-odd effect: The absorption coefficient typically increases with I for n even but decreases for n odd. Our results agree qualitatively with recent experiments.Comment: 15 pages, 13 figures, accepted for publication in Physical Review

Vortex Fractionalization in a Josephson Ladder

We show numerically that, in a Josephson ladder with periodic boundary conditions and subject to a suitable transverse magnetic field, a vortex excitation can spontaneously break up into two or more fractional excitations. If the ladder has N plaquettes, and N is divisible by an integer q, then in an applied transverse field of 1/q flux quanta per plaquette the ground state is a regular pattern of one fluxon every q plaquettes. When one additional fluxon is added to the ladder, it breaks up into q fractional fluxons, each carrying 1/q units of vorticity. The fractional fluxons are basically walls between different domains of the ground state of the underlying 1/q lattice. The fractional fluxons are all depinned at the same applied current and move as a unit. For certain applied fields and ladder lengths, we show that there are isolated fractional fluxons. It is shown that the fractional fluxons would produce a time-averaged voltage related in a characteristic way to the ac voltage frequency.Comment: 13 Figures. 10 page

Distribution of Soils in Ohio that are Described with Fractured Substratums in Unconsolidated Materials

Author Institution: Ohio Department of Natural Resources, Division of Soil and Water Conservation ; USDA-Natural Resources Conservation Service ; School of Natural Resources, The Ohio State UniversitySoil scientists, who systematically made soil surveys of Ohio, compiled the first comprehensive inventory of fractures in unconsolidated parent materials, or C horizons, of soils. Fractures have been documented in the C horizon of 95 soil series extending across 55 Ohio counties. A variety of terms were used to describe these nearly vertical fractures in otherwise massive materials. By convention, structural units are considered a product of soil-forming processes and the use of structural unit terminology has been limited to the solum consisting of O, A, E, and B master horizons and transitional horizons like AB, BE and BC horizons. Thus, terms used to describe soil structure have not been applied to the C horizon, even though the faces of prismatic structural units in the lower part of the B horizon commonly show continuity with fractures in the C horizon. Fractures have been identified in unconsolidated soil parent materials with textures of loam, silt loam, clay loam, silty clay loam, silty clay and clay. Clay films and carbonate coatings on fracture planes in the C horizon of soils indicate that water moves into and through these fractures. Fractures in the C horizon of soils also affect air movement and plant root extension into C horizons

Under Water: How to Green Up Your Roadway Project

Learn effective streambank stabilization techniques and funding resources that can be used to protect your roadways. Presenters will explain how to select the most effective stream bank restoration technique— natural channel design, traditional engineering, or both. Also learn how to maximize water quality and asset protection through stream bank stabilization using case studies that compare cost, form, and function. Lastly, we will review funding opportunities for the proposed green strategies

3D Reuse in PLM for Conceptual Ship Design

Today 3D CAD tools have become more and more used in design processes, allowing amongst other better visualization of product, computer analysis of design, etc. Even so, in ship design, 3d-design is still combined with 2D drawings in the conceptual stage. At this point, developing the design in full 3D is not justifiable, since shipbuilding companies almost consistently use a no-cure no-pay principle at this stage. Using 3D vessel models and -software is just too complex and time-consuming. This, in its turn, causes situations where a lot of rework has to be done, because these drawings must be turned into 3D models in the subsequent stages. A method is needed to support the process and reduce the time it takes. PLM is a holistic business approach which promotes amongst others reuse of information. And the question arises; can PLM reuse simplify the 3D design process for use in conceptual ship design? The main goal of this thesis is to create a framework where a virtual prototype can be built from existing components. The way the author wants to achieve this is by creating a library using PLM tools, where the components can be easily stored and reused in other projects. To do this a PLM reuse framework was adapted to maritime requirements. Additionally, the interfaces between vessel model and library were identified and a method to handle them found. Then these methods were applied to a case, with two different vessels, one of them where all components were designed to requirements and one where components from the previous vessel was reused. From the cases, discussions were made about the challenges discovered and ways to improve the models. The discussions lead to a conclusion that while there are still elements to handle, PLM shows promise in providing a tool to reuse vessel components in the conceptual design stage. This thesis could only look into a few of the aspects in 3D reuse in ship design in one step of the lifecycle. PLM is about integrating data from all the stages and processes together, and the 3D components should be combined with data from these processes connecting the models with e.g. specifications, manuals, BOMs etc. When that is done the full benefits of PLM will be revealed

Water Quality Assessment for Northern Rockies Intermontane Basins

The Northern Rockies Intermontane Basins is one of 59 studies of the U.S. Geological Survey\u27s National Water Quality Assessment (NAWQA) Program. The goals of the program are to (1) describe water-quality conditions for a large part of the nation\u27s streams and aquifers, (2) describe water quality trends, and (3) identify factors affecting water quality. Stream water, bottom sediment, ground water, and fish tissue will be sampled; and stream ecology and habitat will be evaluated. Water quality will be related to ancillary factors. The study area extends along the Continental Divide from Butte, Montana, to the Canadian border, and westward to include the Spokane and Pend Oreille Rivers. Water quality issues in the study area include trace metals, nutrients, degradation of water from increased development, sedimentation, and their effects on aquatic biota. Data collection will be designed to address these issues and provide information for water managers. The assessment includes two years of planning, analysis of existing data, and sampling design; and three years for intensive data collection and interpretation. This will be followed by completion of reports and design and implementation of six years of low-intensity sampling. This cycle will be repeated to assess trends. Tornes, Lan H., 1997, National Water-Quality Assessment Program--Northern Rockies Intermontane Basins: U.S. Geological Survey Fact Sheet FS 97-158, 4 p. Available Onlin

Autogenic versus environmental control during development of river biofilm

In the natural environment, microbial community structure of river biofilm is controlled by biotic and abiotic factors. This study explored the capacity to manipulate the structure of microbial communities by modifying environmental conditions during the course of biofilm development. River epilithic biofilm was cultivated in situ on artificial substrates placed parallel to river water flow. Substrates were incubated for 3 and 5.5 weeks in river to allow natural biofilm development, at two sites with contrasting physico-chemical characteristics. The first site (Aurade´ , Gers, France) was located in an agricultural watershed basin and the second site (Larroque, Haute-Garonne, France) was located in a forested watershed basin. After 3 weeks of biofilm development, a subset of substrates was collected from one site and transplanted to the second site where they remained for 2.5 further weeks. Epilithic bacterial community structure (at 3 weeks from each site and at 5.5 weeks from biofilms with and without transplantation) was assessed using PCR-DGGE of 16S rDNA fragment. Biofilm biomass was estimated using ash free dry mass (AFDM). After 3 weeks of development, biofilms from the two sites exhibited comparable AFDM values (average of 1.4¡0.2 g.mx2). A difference between the two sites was observed after 5.5 weeks of development: AFDM decreased for biofilms from the agricultural watershed basin (from 1.4 to 0.18 g.mx2) as a consequence of grazing pressure (Bithynia), and increased for biofilms from the forested agricultural watershed (from 1.4 to 2.6 g.mx2). Microbial community analyses revealed a differentiated community structure between biofilms from the different sites and exhibited a change of microbial community structure after 5.5 weeks of biofilm development. These observations confirm a process of ecological succession in microbial communities. Changing the incubation site during biofilm development modified the trajectory of these ecological successions, suggesting that site characteristics mainly conditioned the structure of these microbial communities

Learning to play Starcraft with Case-based Reasoning: Investigating issues in large-scale case-based planning

In this master thesis we describe our work in creating a planner for the real-time strategy game Starcraft using case-based reasoning. Our work has been focused on the challenges in creating a usable casebase, and the resulting issues arising from scaling up the casebase.First, we present an agent designed to play Starcraft using plans from our CBR planner, and its architecture. We then move on to describe how this planner works, and how it overcomes the challenges in scaling up.We then present several experiments designed to measure how well our approach works given the limitations we have set. Finally, we discuss our results, and provide some interesting unsolved challenges which may benefit from further investigation

Number of rooms in the same fire cell

Master i brannsikkerhet Fakultet for ingeniør- og naturvitenskap, institutt for sikkerhet, kjemi- og bioingeniørfag, campus HaugesundStudenter har et grunnleggende ønske om å bo sentralt, og i nærheten av undervisningslokalene til utdanningsstedet. Regjeringen har lagt til rette for å øke antall studentboliger i regi av studentsamskipnader, men grunnet økende antall studenter har studentsamskipnader en dekningsgrad på kun 14,52%. Dette har ført til at studenter er avhengige av å leie rom i kollektiv eller leiligheter av privatpersoner eller utleieaktører. Eiere av utleieleiligheter eller bygårder prioriterer ofte ikke økt brannsikkerhet, men profitt. Dette har ført til hybilifisering, hvor eier etablerer mange små soverom i eksisterende leilighet, for å øke antall leietakere, og på den måten får større inntjening per måned. I henhold til oppgraderingsplikten skal samtlige byggverk oppført før 1985, minimum oppgraderes til å tilfredsstille kravene gitt i BF85. Hybelleiligheter, utleieleiligheter og kollektiv er ikke nevnt i noen regelverk fra BF85 til dagens regelverk TEK17. Slike objekter anses å være vanlige leiligheter, selv om bruken og forutsetningene endres betydelig ved omgjøring fra leilighet til utleieleilighet/hybelleilighet. Formålet med oppgaven er å undersøke om kravene i norske regelverk gir tilstrekkelig personsikkerhet ved brann i utleieleiligheter. For å undersøke dette er det foretatt et litteraturstudium som sammenlikner krav i norske regelverk, fra BF85 til TEK17, samt utenlandske regelverk. Det er også utført brann- og evakueringssimuleringer for å undersøke om sikkerhetsnivået i et typisk studentkollektiv er tilstrekkelig. Resultatene fra brann- og evakueringssimuleringer viser at eldre utleieleiligheter med krav fra BF85, hvor det er krav til én røykdetektor per etasje, ikke vil gi tilstrekkelig sikkerhet for beboerne. Få deteksjonsmuligheter blir særlig sårbart ved økende antall soverom/hybler. Studentene benytter ofte soverom som oppholdsrom, og har gjerne kjøleskap og andre småelektriske artikler på rommet. Dette øker sannsynligheten for branntilløp, og med mange personer i samme branncelle vil sjansen for storbrann øke i takt med personbelastningen. For å redusere sannsynligheten for storbranner i utleieleiligheter foreslås det å granske om slike objekter bør få økt risikoklasse, fra risikoklasse 4 til 6. Eventuelt bli pålagt å utføre soverom/hybler som egne brannceller, utstyrt med brannalarmanlegg, med deteksjonspunkter i samtlige soverom og fellesarealer. For å ytterlig øke brannsikkerheten bør installering av sprinkleranlegg, samt etablering av ytterligere rømningsveier vurderes. Det bør også stilles forskriftskrav om uavhengig kontroll av utleieobjekter for å avdekke, og utbedre graverende forhold med tanke på brann og personsikkerhet.ING500

Landau-Zener-Stuckelberg interferometry

A transition between energy levels at an avoided crossing is known as a Landau-Zener transition. When a two-level system (TLS) is subject to periodic driving with sufficiently large amplitude, a sequence of transitions occurs. The phase accumulated between transitions (commonly known as the Stuckelberg phase) may result in constructive or destructive interference. Accordingly, the physical observables of the system exhibit periodic dependence on the various system parameters. This phenomenon is often referred to as Landau-Zener-Stuckelberg (LZS) interferometry. Phenomena related to LZS interferometry occur in a variety of physical systems. In particular, recent experiments on LZS interferometry in superconducting TLSs (qubits) have demonstrated the potential for using this kind of interferometry as an effective tool for obtaining the parameters characterizing the TLS as well as its interaction with the control fields and with the environment. Furthermore, strong driving could allow for fast and reliable control of the quantum system. Here we review recent experimental results on LZS interferometry, and we present related theory.Comment: 34 single-column pages, 11 figure