6,138 research outputs found
Radiation heat transfer within the screte element method - relevance, implementation and examples -
Current developments in the energy sector increasingly demand the consideration of fuels with much larger particle sizes, either from alternative sources or due to a reduced pre-processing effort. In numerical simulations of such systems the particles can no longer be considered as non-colliding material points. Municipal waste incineration on grates or wood pellet combustion in domestic boilers are such examples, where the Discrete Element Method (DEM) can be applied to extend the Lagrange tracking of moving particles to a mechanically and thermally fully interacting flow of reacting granular material. In some situations where sufficiently large time scale differences between the processes in the gas phase and in the solid phase exist, distinctive interfaces can be identified between domains, thus allowing a different modelling in these regions. The treatment of the radiative heat transfer between such domains poses particular difficulties at the interfaces. Based on the two exemplary applications mentioned, details of the modelling
approach are discussed and corresponding results presented
Ewing-Sarkom mit primÀrer Lungenmetastasierung:Analyse der Daten von 182 Patienten aus den (EI)CESS-Studien ; Patientencharakteristik, Therapiestrategien und prognostische Faktoren
Seit den 80er Jahren wurden in den (EI)CESS-Studien 182 paediatrische Patienten mit Ewing-Sarkom und pulmonaler Metastasierung dokumentiert. Die Arbeit bietet einen Ăberblick ĂŒber die Patientencharakteristik und stellt als prognostische Faktoren insbesondere eine beidseitige Lungenbestrahlung und eine intensive Chemotherapie als gĂŒnstige Faktoren heraus. Die Daten der Analyse trugen wesentlich zur Konzeption des Therapieschemas der internationalen Ewing-Sarkom-Studie Euro-E.W.I.N.G 99 bei
Purification and Characterization of Diacylglycerol Pyrophosphate Phosphatase from Saccharomyces cerevisiae
Diacylglycerol pyrophosphate (DGPP) phosphatase is a novel membrane-associated enzyme that catalyzes the dephosphorylation of the ÎČ phosphate of DGPP to yield phosphatidate and P. DGPP phosphatase was purified 33,333-fold from Saccharomyces cerevisiae by a procedure that included Triton X-100 solubilization of microsomal membranes followed by chromatography with DE53, Affi-Gel Blue, hydroxylapatite, and Mono Q. The procedure resulted in the isolation of an apparent homogeneous protein with a subunit molecular mass of 34 kDa. DGPP phosphatase activity was associated with the 34-kDa protein. DGPP phosphatase had a broad pH optimum between 6.0 and 8.5 and was dependent on Triton X-100 for maximum activity. The enzyme was inhibited by divalent cations, NaF, and pyrophosphate and was relatively insensitive to thioreactive agents. The turnover number (molecular activity) for the enzyme was 5.8 Ă 103 min-1 at pH 6.5 and 30°C. DGPP phosphatase exhibited typical saturation kinetics with respect to DGPP (Km = 0.55 mol %). The Km for DGPP was 3-fold greater than its cellular concentration (0.18 mol %). DGPP phosphatase also catalyzed the dephosphorylation of phosphatidate, but this dephosphorylation was subsequent to the dephosphorylation of the ÎČ phosphate of DGPP. The dependence of activity on phosphatidate (Km = 2.2 mol %) was cooperative (Hill number = 2.0). DGPP was the preferred substrate for the enzyme with a specificity constant (Vmax /Km) 10-fold greater than that for phosphatidate. In addition, DGPP potently inhibited (Ki = 0.35 mol %) the dephosphorylation of phosphatidate by a competitive mechanism whereas phosphatidate did not inhibit the dephosphorylation of DGPP. DGPP was neither a substrate nor an inhibitor of pure phosphatidate phosphatase from S. cerevisiae. DGPP was synthesized from phosphatidate via the phosphatidate kinase reaction
Lowering IceCube's energy threshold for point source searches in the Southern Sky
Observation of a point source of astrophysical neutrinos would be a "smoking gun" signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current Îœ ÎŒ interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (~100 TeV) starting event in the sample found that this event alone represents a 2.8Ï deviation from the hypothesis that the data consists only of atmospheric background.Fil: Aartsen, M. G.. University of Adelaide; AustraliaFil: Abraham, K.. Technische UniversitĂ€t MĂŒnchen; AlemaniaFil: Ackermann, M.. Deutsches Elektronen-Synchrotron; AlemaniaFil: Adams, J.. University Of Canterbury; Nueva ZelandaFil: Aguilar, J. A.. UniversitĂ© Libre de Bruxelles; BĂ©lgicaFil: Golup, Geraldina Tamara. ComisiĂłn Nacional de EnergĂa AtĂłmica. Gerencia del Ărea de EnergĂa Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte; ArgentinaFil: Wallace, A.. University of Adelaide; AustraliaFil: Wallraff, M.. Rwth Aachen University; AlemaniaFil: Wandkowsky, N.. University of Wisconsin; Estados UnidosFil: Weaver, Ch.. University of Alberta; CanadĂĄFil: Wendt, C.. University of Wisconsin; Estados UnidosFil: Westerhoff, S.. University of Wisconsin; Estados UnidosFil: Whelan, B. J.. University of Adelaide; AustraliaFil: Whitehorn, N.. University of California at Berkeley; Estados UnidosFil: Wickmann, S.. Rwth Aachen University; AlemaniaFil: Wiebe, K.. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Wiebusch, C. H.. Rwth Aachen University; AlemaniaFil: Wille, L.. University of Wisconsin; Estados UnidosFil: Williams, D. R.. University of Alabama at Birmingahm; Estados UnidosFil: Wills, L.. Drexel University; Estados UnidosFil: Wissing, H.. University of Maryland; Estados UnidosFil: Wolf, M.. Stockholms Universitet; SueciaFil: Wood, T. R.. University of Alberta; CanadĂĄFil: Woschnagg, K.. University of California at Berkeley; Estados UnidosFil: Xu, D. L.. University of Wisconsin; Estados UnidosFil: Xu, X. W.. Southern University; Estados UnidosFil: Xu, Y.. Stony Brook University; Estados UnidosFil: Yanez, J. P.. Deutsches Elektronen-Synchrotron; AlemaniaFil: Yodh, G.. University of California at Irvine; Estados UnidosFil: Yoshida, S.. Chiba University; JapĂłnFil: Zoll, M.. Stockholms Universitet; Sueci
Ultra-Relativistic Magnetic Monopole Search with the ANITA-II Balloon-borne Radio Interferometer
We have conducted a search for extended energy deposition trails left by
ultra-relativistic magnetic monopoles interacting in Antarctic ice. The
non-observation of any satisfactory candidates in the 31 days of accumulated
ANITA-II flight data results in an upper limit on the diffuse flux of
relativistic monopoles. We obtain a 90% C.L. limit of order
10^{-19}/(cm^2-s-sr) for values of Lorentz boost factor 10^{10}<gamma at the
anticipated energy E=10^{16} GeV. This bound is stronger than all previously
published experimental limits for this kinematic range.Comment: updated to version accepted by Phys. Rev.
Dementia in People with Severe/Profound Intellectual (and Multiple) Disabilities:Practice-Based Observations of Symptoms
Introduction Observable dementia symptoms are hardly studied in people with severe/profound intellectual (and multiple) disabilities (SPI(M)D). Insight in symptomatology is needed for timely signaling/diagnosis. This study aimed to identify practice-based observations of dementia symptoms in this population. Methods Care professionals and family members were invited to complete a survey about symptoms. Quantitatively analyzed survey data were further deepened through semi-structured interviews with care professionals having vast experience in signaling/diagnosing dementia in this population. Symptoms were categorized using a symptom matrix. Results Survey respondents and interviewees frequently observed a decline in activities of daily living (ADL) functioning and behavioral and psychological changes, like increased irritability, anxiety, apathy and decreased eating/drinking behavior. Cognitive symptoms were particularly recognized in persons with verbal communication and/or walking skills. To lesser extent motor changes and medical comorbidities were reported. Conclusion Increased insight in dementia symptoms contributes to developing a dedicated screening instrument for dementia in people with SPI(M)D
Dementia in People with Severe/Profound Intellectual (and Multiple) Disabilities:Applicability of Items in Dementia Screening Instruments for People with Intellectual Disabilities
Introduction: Diagnosing dementia in people with severe/profound intellectual (and multiple) disabilities (SPI(M)D) is complex. Whereas existing dementia screening instruments as a whole are unsuitable for this population, a number of individual items may apply. Therefore, this study aimed to identify applicable items in existing dementia screening instruments. Methods: Informant interviews about 40 people with SPI(M)D were conducted to identify applicable items in the Dementia Scale for Down Syndrome, Behavioral and Psychological Symptoms of Dementia in Down Syndrome II scale, Dementia Questionnaire for persons with Mental Retardation and Social competence Rating scale for people with Intellectual Disabilities. Results: Among 193 items, 101 items were found applicable, categorized in 5 domains: behavioral and psychological functioning (60 items), cognitive functioning (25), motor functioning (6), activities of daily living (5) and medical comorbidities (5). Conclusion: Identifying applicable items for people with SPI(M)D is an essential step in developing a dedicated dementia screening instrument for this population
Lateral Distribution of Muons in IceCube Cosmic Ray Events
In cosmic ray air showers, the muon lateral separation from the center of the
shower is a measure of the transverse momentum that the muon parent acquired in
the cosmic ray interaction. IceCube has observed cosmic ray interactions that
produce muons laterally separated by up to 400 m from the shower core, a factor
of 6 larger distance than previous measurements. These muons originate in high
pT (> 2 GeV/c) interactions from the incident cosmic ray, or high-energy
secondary interactions. The separation distribution shows a transition to a
power law at large values, indicating the presence of a hard pT component that
can be described by perturbative quantum chromodynamics. However, the rates and
the zenith angle distributions of these events are not well reproduced with the
cosmic ray models tested here, even those that include charm interactions. This
discrepancy may be explained by a larger fraction of kaons and charmed
particles than is currently incorporated in the simulations
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