242 research outputs found
Extension of the Measurement Capabilities of the Quadrupole Resonator
The Quadrupole Resonator, designed to measure the surface resistance of
superconducting samples at 400 MHz has been refurbished. The accuracy of its
RF-DC compensation measurement technique is tested by an independent method. It
is shown that the device enables also measurements at 800 and 1200 MHz and is
capable to probe the critical RF magnetic field. The electric and magnetic
field configuration of the Quadrupole Resonator are dependent on the excited
mode. It is shown how this can be used to distinguish between electric and
magnetic losses.Comment: 6 pages, g figure
EarthN: A new Earth System Nitrogen Model
The amount of nitrogen in the atmosphere, oceans, crust, and mantle have
important ramifications for Earth's biologic and geologic history. Despite this
importance, the history and cycling of nitrogen in the Earth system is poorly
constrained over time. For example, various models and proxies contrastingly
support atmospheric mass stasis, net outgassing, or net ingassing over time. In
addition, the amount available to and processing of nitrogen by organisms is
intricately linked with and provides feedbacks on oxygen and nutrient cycles.
To investigate the Earth system nitrogen cycle over geologic history, we have
constructed a new nitrogen cycle model: EarthN. This model is driven by mantle
cooling, links biologic nitrogen cycling to phosphate and oxygen, and
incorporates geologic and biologic fluxes. Model output is consistent with
large (2-4x) changes in atmospheric mass over time, typically indicating
atmospheric drawdown and nitrogen sequestration into the mantle and continental
crust. Critical controls on nitrogen distribution include mantle cooling
history, weathering, and the total Bulk Silicate Earth+atmosphere nitrogen
budget. Linking the nitrogen cycle to phosphorous and oxygen levels, instead of
carbon as has been previously done, provides new and more dynamic insight into
the history of nitrogen on the planet.Comment: 36 pages, 12 figure
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Photodesorption from copper, beryllium and thin films
Ever increasing circulating currents in electron-positron colliders and light sources demand lower and lower photodesportion (PSD) from the surfaces of their vacuum chambers and their photon absorbers. This is particularly important in compact electron storage rings and B meson factories where photon power of several kw cm{sup {minus}1} is deposited on the surfaces. Given the above factors we have measured PSD from 1m long bars of (1) solid copper and solid beryllium, and (2), TiN, Au and C thin films deposited on solid copper bars. Each sample was exposed to about 10{sup 23} photons/m with a critical energy of 500 eV at the VUV ring of the NSLS. PSD was recorded for two conditions: after a 200{degrees}C bake-out and after an Ar glow discharge cleaning. In addition, we also measured reflected photons, photoelectrons and desorption as functions of normal, 75 mrad, 100 mrad, and 125 mrad incident photons. 15 refs., 8 figs., 1 tab
Barium isotopic composition of the mantle: Constraints from carbonatites
To investigate the behaviour of Ba isotopes during carbonatite petrogenesis and to explore the possibility of using carbonatites to constrain the Ba isotopic composition of the mantle, we report high-precision Ba isotopic analyses of: (1) carbonatites and associated silicate rocks from the only active carbonatite volcano, Oldoinyo Lengai, Tanzania, and (2) Archean to Cenozoic carbonatites from Canada, East Africa, Germany and Greenland. Carbonatites and associated phonolites and nephelinites from Oldoinyo Lengai have similar ÎŽ137/134 Ba values that range from +0.01 to +0.03â°, indicating that Ba isotope fractionation during carbonatite petrogenesis is negligible. The limited variation in ÎŽ137/134 Ba values from â0.03 to +0.09â° for most carbonatite samples suggests that their mantle sources have a relatively homogeneous Ba isotopic composition. Based on the carbonatites investigated in this work, the average ÎŽ137/134 Ba value of their mantle sources is estimated to be +0.04 ± 0.06â° (2SD, n = 16), which is similar to the average value of +0.05 ± 0.06â° for mid-ocean ridge basalts. The lower ÎŽ137/134 Ba value of â0.08â° in a Canadian sample and higher ÎŽ137/134 Ba values of +0.14â° and +0.23â° in two Greenland samples suggest local mantle isotopic heterogeneity that may reflect the incorporation of recycled crustal materials in their sources
On the ambiguity of 1,3,2-benzodiazaboroles as donor/acceptor functionalities in luminescent molecules
A series of 1,3-bis(perfluoroaryl)-2-(hetero)aryl-1,3,2-benzodiazaboroles, 1,3-FAr2-2-Ar-1,3,2-N2BC6H4 (Ar = Ph, FAr = C6F5 5; Ar = Ph, FAr = 4-C5F4N 6; Ar = Ph, FAr = 4-NCC6F4 7; Ar = 2-C4H3S, FAr = C6F5 8; Ar = 2-C4H3S, FAr = 4-C5F4N 9; Ar = 2-C4H3S, FAr = 4-NCC6F4 10), were synthesised by cyclocondensation of the adducts PhBBr2·PPh3 or 2-thienylBBr2·PPh3 with N,NâČ-bis(perfluoroaryl)-o-phenylenediamines in the presence of 2,2,6,6-tetramethylpiperidine. Similar treatments of the PPh3 adducts of 4-(1âČ,3âČ-diethyl-1âČ,3âČ,2âČ-benzodiazaborolyl)-phenyldibromoborane with the corresponding diamines gave rise to the pushâpull compounds, C6H4(NEt)2B-1,4-C6H4-B(NFAr)2C6H4 (FAr = C6F5 11; 4-C5F4N 12) and C6H4(NEt)2B-2,5-C4H2S-B(NFAr)2C6H4 (FAr = C6F5 13; 4-C5F4N 14). The X-ray structures of 8, 11, 12 and 13 were determined. Electronic structure calculations reveal that the LUMOs are located at the perfluoroaryl groups in 5â14; thus the fluorinated benzodiazaborolyl groups are considered as electron-withdrawing moieties. These moieties differ from alkylated benzodiazaborolyl groups which are regarded as donors. The emission spectra for 5â14 show charge transfer bands with significant solvatochromism and large Stokes shifts (6100â12500 cmâ1 in cyclohexane and 8900â15900 cmâ1 in CH2Cl2). The emissions of the benzodiazaboroles, 5â10, arise from a different charge transfer (CT) process to the local charge transfer (LCT) process typically found in many fluorescent benzodiazaboroles. This novel remote charge transfer (RCT) process involving the perfluoroaryl groups is supported by CAM-B3LYP computations. The pushâpull systems 11â14 here give fluorescent emissions with moderate to high fluorescence quantum yields (65â97%) that arise from the usual LCT process only
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Predicting survival from colorectal cancer histology slides using deep learning: A retrospective multicenter study
BACKGROUND: For virtually every patient with colorectal cancer (CRC), hematoxylin-eosin (HE)-stained tissue slides are available. These images contain quantitative information, which is not routinely used to objectively extract prognostic biomarkers. In the present study, we investigated whether deep convolutional neural networks (CNNs) can extract prognosticators directly from these widely available images.
METHODS AND FINDINGS: We hand-delineated single-tissue regions in 86 CRC tissue slides, yielding more than 100,000 HE image patches, and used these to train a CNN by transfer learning, reaching a nine-class accuracy of >94% in an independent data set of 7,180 images from 25 CRC patients. With this tool, we performed automated tissue decomposition of representative multitissue HE images from 862 HE slides in 500 stage I-IV CRC patients in the The Cancer Genome Atlas (TCGA) cohort, a large international multicenter collection of CRC tissue. Based on the output neuron activations in the CNN, we calculated a "deep stroma score," which was an independent prognostic factor for overall survival (OS) in a multivariable Cox proportional hazard model (hazard ratio [HR] with 95% confidence interval [CI]: 1.99 [1.27-3.12], p = 0.0028), while in the same cohort, manual quantification of stromal areas and a gene expression signature of cancer-associated fibroblasts (CAFs) were only prognostic in specific tumor stages. We validated these findings in an independent cohort of 409 stage I-IV CRC patients from the "Darmkrebs: Chancen der VerhĂŒtung durch Screening" (DACHS) study who were recruited between 2003 and 2007 in multiple institutions in Germany. Again, the score was an independent prognostic factor for OS (HR 1.63 [1.14-2.33], p = 0.008), CRC-specific OS (HR 2.29 [1.5-3.48], p = 0.0004), and relapse-free survival (RFS; HR 1.92 [1.34-2.76], p = 0.0004). A prospective validation is required before this biomarker can be implemented in clinical workflows.
CONCLUSIONS: In our retrospective study, we show that a CNN can assess the human tumor microenvironment and predict prognosis directly from histopathological images
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200-GeV ISA with room temperature magnets
A conceptual design study of 200-GeV proton intersecting storage accclerators with room temperature magnets is presented. The key to this study was thc desire to keep the electric power consumptiom to an acceptable level (40 MW). The design has been optimized by choosing small-gap (4 cm) aluminum coil dipoles operating at about 15 kG. The luminosity of this machine is limited to about 10/sup 32/ cm-/sup -2/ sec/sup -1/ by transverse space-charg e effects. An order of magnitude higher luminositics can be obtained by adding a booster of modest cost. A novel vacuum system using distributed Ti-sublimation pumps results in considerable savings. A cost comparison with a high-luminosity superconducting machine is given. (auth
Tourmaline Reference Materials for the In Situ Analysis of Oxygen and Lithium Isotope Ratio Compositions
Three tourmaline reference materials sourced from the Harvard Mineralogical and Geological Museum (schorl 112566, dravite 108796 and elbaite 98144), which are already widely used for the calibration of in situ boron isotope measurements, are characterised here for their oxygen and lithium isotope compositions. Homogeneity tests by secondary ion mass spectrometry (SIMS) showed that at subânanogram test portion masses their 18O/16O and 7Li/6Li isotope ratios are constant within ± 0.27â° and ± 2.2â° (1s), respectively. The lithium mass fractions of the three materials vary over three orders of magnitude. SIMS homogeneity tests showed variations in 7Li/28Si between 8% and 14% (1s), which provides a measure of the heterogeneity of the Li contents in these three materials. Here we provide recommended values for ÎŽ18O, Îâ17O and ÎŽ7Li for the three Harvard tourmaline reference materials based on results from bulk mineral analyses from multiple, independent laboratories using laserâ and stepwise fluorination gas mass spectrometry (for O), and solution multiâcollector inductively coupled plasmaâmass spectroscopy (for Li). These bulk data also allow us to assess the degree of interâlaboratory data that might be present in such datasets. This work also reâevaluates the major element chemical composition of the materials by electron probe microanalysis and investigates the presence of a chemical matrix effect on SIMS instrumental mass fractionation with regards to ÎŽ18O determinations, which was found to be < 1.6â° between these three materials. The final table presented here provides a summary of the isotope ratio values that we have determined for these three materials. Depending on their starting mass either 128 or 256 splits have been produced of each material, assuring their availability for many years into the future
Improving Project Logistics by using IoT
This BachelorŽs thesis is made on behalf of WÀrtsilÀ Energy Solutions, Project Logistics & Transport Management department whose main task is to coordinate and ensure that materials and products are transported to the right place and on time in Project Logistics.
This thesis examines how you could improve WÀrtsilÀŽs Project Logistics by using Internet of Things. By developing IoT, there has been an increased chance to get more information about transports than before and WÀrtsilÀ is currently looking for new solutions to use that could improve their current logistics system. The purpose of this thesis is to review new, and used, solutions on the market, and then see what could work in practice at WÀrtsilÀ.
Material to this thesis are gathered from books, web pages and articles that reviewed interesting IoT solutions and which also gave examples on different solutions that are used by other companies in the same business.
The Result is two different methods that could improve WÀrtsilÀŽs Project Logistics in different occasions. These results are intended to give tips on how IoT could improve the departmentŽs ways of coordinating and check transports and logistics within a project.Detta examensarbete Àr gjort i uppdrag av WÀrtsilÀ Energy Solutions, Project logistics & Transport Management avdelningen vars huvuduppgift Àr att koordinera och se till att material och produkter transporteras till rÀtt plats i rÀtt tid inom projekt logistiken.
Examensarbetet behandlar hur man kunde förbÀttra WÀrtsilÀs projekt logistik genom att anvÀnda Internet of Things. Genom att IoT har utvecklats har det uppstÄtt möjligheter att fÄ fram mer information om transporter Àn tidigare och WÀrtsilÀ söker för tillfÀllet nya lösningar som kunde anvÀndas för att förbÀttra deras nuvarande logistiksystem. Syftet med arbetet Àr att gÄ igenom nya, men Àven redan befintliga, lösningar som anvÀnds pÄ dagens marknad - för att sedan se vad som kunde fungera i praktiken hos WÀrtsilÀ.
Material till arbetet Àr samlat frÄn böcker, webbsidor och artiklar som gick igenom intressanta IoT lösningar och som ocksÄ gav exempel pÄ hur olika system fungerar och anvÀnds av andra företag inom samma bransch.
Slutresultatet blev tvÄ olika metoder som kunde förbÀttra WÀrtsilÀs projekt logistik vid olika tillfÀllen. Dessa resultat Àr tÀnkta för att ge tips pÄ hur IoT kunde förbÀttra avdelningens sÀtt hur man koordinerar och granskar transporter och logistiken inom ett projekt
Corrosion challenges towards a sustainable society
A global transition towards more sustainable, affordable and reliable energy systems is being stimulated by the Paris Agreement and the United Nation's 2030 Agenda for Sustainable Development. This poses a challenge for the corrosion industry, as building climate-resilient energy systems and infrastructures brings with it a long-term direction, so as a result the long-term behaviour of structural materials (mainly metals and alloys) becomes a major prospect. With this in mind "Corrosion Challenges Towards a Sustainable Society" presents a series of cases showing the importance of corrosion protection of metals and alloys in the development of energy production to further understand the science of corrosion, and bring the need for research and the consequences of corrosion into public and political focus. This includes emphasis on the limitation of greenhouse gas emissions, on the lifetime of infrastructures, implants, cultural heritage artefacts, and a variety of other topics
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