4,439 research outputs found
Design of a 75 K. W. power station
No full textCitation: Donly, Max C. and Walker, Carroll. Design of a 75 K. W. power station. Senior thesis, Kansas State Agricultural College, 1908.Introduction: The first consideration in installing a power plant is the cost. Whether or not the money invested will bring returns, is the proposition that outweighs all others. This resolves itself into the supply and demand for power and the cost of producing the power and installing the necessary machinery
A Transfer Report on the Development of a Framework to Evaluate Search Interfaces for their Support of Different User Types and Search Tactics
No full textAs the understanding of search systems, user needs and seeking strategies is developing, the design of search user interfaces is evolving to support more complicated and exploratory forms of search. With the design of new search features that enable these richer modes of exploration, comes the need to better understand the support they provide. In this report a new evaluation framework is presented that analyses search features for how they a) contribute to an overall interface, b) allow users to carry out different search tactics, and c) support different types of users and their needs. The novel contributions of the framework improve on some of the limitations of typical user studies, and allow search systems to be systematically analysed in much more detail and in much less time. The presented evaluation framework is then validated in three ways. First the validity of the models used as the building blocks of the framework are investigated through related work. Second the method of integrating these building-block models is validated and strengthened by consensus of expert opinion. Third, the overall approach is validated by comparing its analyses to the results of previously carried out user studies. The validation process has shown both the value of the framework and identified areas of future work that should be addressed for the framework to be completed. This report concludes with the set of contributions that the framework makes, and why the remaining work will be challenging, but critical to the final design
Synthesis and oxidation behaviour of Ta-Al-C MAX phases
No full textMAX-phase materials, a class of ternary carbides and nitrides that combine favorable properties of metals (conductivity and toughness) and ceramics (high temperature strength) have been shown to autonomously heal micro-cracks by high temperature oxidation. The investigation of Ta and Al containing MAX phases (Ta2AlC & Ta4AlC3) could render self-healing materials at lower temperatures. Mixed (Ta2AlC and Ta4AlC3) and pure dense bulk Ta2AlC MAX phase was synthesized by spark plasma sintering (SPS) of elemental powders. The oxidation reactions of Ta-Al-C MAX phase powders were studied with differential thermal analysis (DTA). The oxidation kinetics of dense bulk Ta-Al-C MAX phase was studied by thermal gravimetric analysis (TGA). The microstructure and composition of the MAX phase materials and its oxides was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray microanalysis with electron probe microanalysis (EPMA), and X-ray photoelectron spectroscopy (XPS). Linear oxidation kinetics, inward oxide growth and formation of mainly porous Ta-oxides were observed for isothermal oxidation of dense bulk Ta2AlC and mixed MAX phase. Based on the results obtained in this work, the oxides scales formed in the 600 – 800 °C temperature range are believed to consist of various metastable and/or amorphous oxides. Full oxidation of the MAX phase above 900 °C results in the formation of Ta2O5 and ternary TaAlO4. It was found that TaAl-C MAX phases cannot self-heal microcracks by formation of a protective oxide scale at elevated temperatures.Mechanical, Maritime and Materials EngineeringMaterial Science and Engineerin
The subzero microbiome: Microbial activity in frozen and thawing soils
No full textMost of the Earth's biosphere is characterized by low temperatures (<5 °C) and cold-adapted microorganisms are widespread. These psychrophiles have evolved a complex range of adaptations of all cellular constituents to counteract the potentially deleterious effects of low kinetic energy environments and the freezing of water. Microbial life continues into the subzero temperature range, and this activity contributes to carbon and nitrogen flux in and out of ecosystems, ultimately affecting global processes. Microbial responses to climate warming and in particular, thawing of frozen soils are not yet well understood although the threat of microbial contribution to positive feedback of carbon flux is substantial. To date, several studies have examined microbial community dynamics in frozen soils and permafrost due to changing environmental conditions, and some have undertaken the complicated task of characterizing microbial functional groups and how their activity changes with changing conditions, either in situ or by isolating and characterizing macromolecules. With increasing temperature and wetter conditions microbial activity of key microbes and subsequent efflux of greenhouse gases also increase. In this review, we aim to provide an overview of microbial activity in seasonally frozen soils and permafrost. With a more detailed understanding of the microbiological activities in these vulnerable soil ecosystems, we can begin to predict and model future expectations for carbon release and climate change.Peer reviewe
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Walker, Jane (Death, 1903-03-02)
No full textAddress: Hyde Park 1033 Wesley Ave.Age at death: 87 yrs.Pg 24/54/1903/F W W/N. C./Age/Dr. Max. Koehler/Jos. Schreiber/Spring GroveOriginal record filed in drawer labeled 'WALKER-_WALTEN'
Global analysis of cell cycle gene expression of the legume symbiont Sinorhizobium meliloti
No full textIn α-proteobacteria, strict regulation of cell cycle progression is necessary for the specific cellular differentiation required for adaptation to diverse environmental niches. The symbiotic lifestyle of Sinorhizobium meliloti requires a drastic cellular differentiation that includes genome amplification. To achieve polyploidy, the S. meliloti cell cycle program must be altered to uncouple DNA replication from cell division. In the α-proteobacterium Caulobacter crescentus, cell cycle-regulated transcription plays an important role in the control of cell cycle progression but this has not been demonstrated in other α-proteobacteria. Here we describe a robust method for synchronizing cell growth that enabled global analysis of S. meliloti cell cycle-regulated gene expression. This analysis identified 462 genes with cell cycle-regulated transcripts, including several key cell cycle regulators, and genes involved in motility, attachment, and cell division. Only 28% of the 462 S. meliloti cell cycle-regulated genes were also transcriptionally cell cycle-regulated in C. crescentus. Furthermore, CtrA- and DnaA-binding motif analysis revealed little overlap between the cell cycle-dependent regulons of CtrA and DnaA in S. meliloti and C. crescentus. The predicted S. meliloti cell cycle regulon of CtrA, but not that of DnaA, was strongly conserved in more closely related α-proteobacteria with similar ecological niches as S. meliloti, suggesting that the CtrA cell cycle regulatory network may control functions of central importance to the specific lifestyles of α-proteobacteria.National Institutes of Health (U.S.) (Grant GM31010)National Institutes of Health (U.S.) (Grant P30 ES002109)National Cancer Institute (U.S.) (Award P30 CA14051
L'immagine opaca. Il cinema di Max Ophuls
No full textChe cinema è quello di Max Ophuls? In che modo si inserisce nella storia del linguaggio cinematografico? Si tratta di un autore “classico”? Ma che cosa vuol dire “cinema narrativo classico”? E ancora: in che modo ha senso, oggi, studiare il cinema di un “autore”? In quale accezione leggiamo questo termine e in che rapporto sta con i macrosistemi (i generi, i contesti produttivi, la storia della tecnologia...) che sono stati l’oggetto, negli ultimi anni, della riflessione storiografica sul cinema? Il libro si propone di rispondere a tali questioni rileggendo l’opera di Max Ophuls (1902-1957) attraverso un’analisi stilistica fondata sul concetto di classicità ibrida e sulla reinterpretazione dell’idea di stile, visto come confronto incessante e forse irrisolvibile tra codice e scarto, tra norma e trasgressione.What kind of cinema is Max Ophuls's? In which way it enters the story of cinematic language? Is he a "classic" author? But what does it mean "classic narrative cinema"? Plus: does it make sense, today, to study the film of an "author"? What do we mean by this term and what kind of relation does it have with the macro systems (genres, productive contexts, history of technology...) that have been, in the recent years, the main focus of the historiographical reflection on film? The book aims at answering those questions through a re-reading of the work of Max Ophuls (1902-1957), with a stylistical analysis founded on the idea of hybrid classicism as well as on the reinterpretation of the idea of style, seen as a continuous -and maybe unsolvable - confrontation between code and deviation, rule and transgression
Arctic tundra soil bacterial communities active at subzero temperatures detected by stable isotope probing
No full textArctic soils store vast amounts of carbon and are subject to intense climate change. While effects of thaw on the composition and activities of Arctic tundra microorganisms has been examined extensively, little is known about the consequences of temperature fluctuations within the subzero range in seasonally frozen or permafrost soils. This study identified tundra soil bacteria active at subzero temperatures using stable isotope probing (SIP). Soils from Kilpisjärvi, Finland were amended with 13C-cellobiose and incubated at 0, -4, and -16°C for up to 40 weeks. 16S rRNA gene sequence analysis of 13C-labelled DNA revealed distinct subzero-active bacterial taxa. The SIP experiments demonstrated that diverse bacteria, including members of Candidatus Saccharibacteria, Melioribacteraceae, Verrucomicrobiaceae, Burkholderiaceae, Acetobacteraceae, Armatimonadaceae, and Planctomycetaceae were capable of synthesizing 13C-DNA at subzero temperatures. Differences in subzero temperature optima were observed, for example with members of Oxalobacteraceae and Rhizobiaceae found to be more active at 0°C than at -4°C or -16°C, whereas Melioribacteriaceae were active at all subzero temperatures tested. Phylogeny of 13C-labelled 16S rRNA genes from the Melioribacteriaceae, Verrucomicrobiaceae, and Candidatus Saccharibacteria suggested that these taxa formed subzero-active clusters closely related to members from other cryo-environments. This study demonstrates that subzero temperatures impact active bacterial community composition and activity which may influence biogeochemical cycles.Peer reviewe
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