225 research outputs found
Survival and complete convergence for a branching annihilating random walk
We study a discrete-time branching annihilating random walk (BARW) on the
-dimensional lattice. Each particle produces a Poissonian number of
offspring with mean which independently move to a uniformly chosen site
within a fixed distance from their parent's position. Whenever a site is
occupied by at least two particles, all the particles at that site are
annihilated. We prove that for any the process survives when is
sufficiently large. For fixed we show that the process dies out if is
too small or too large. Furthermore, we exhibit an interval of -values for
which the process survives and possesses a unique non-trivial ergodic
equilibrium for sufficiently large. We also prove complete convergence for
that case
Survival and complete convergence for a branching annihilating random walk
We study a discrete-time branching annihilating random walk (BARW) on the -dimensional lattice. Each particle produces a Poissonian number of offspring with mean which independently move to a uniformly chosen site within a fixed distance from their parent's position. Whenever a site is occupied by at least two particles, all the particles at that site are annihilated. We prove that for any the process survives when is sufficiently large. For fixed we show that the process dies out if is too small or too large. Furthermore, we exhibit an interval of -values for which the process survives and possesses a unique non-trivial ergodic equilibrium for sufficiently large. We also prove complete convergence for that case
Seasonal dynamics modifies fat of oxygen, nitrate, and organic micropollutants during bank filtration - temperature-dependent reactive transport modeling of field data
Bank filtration is considered to improve water quality through microbially mediated degradation of pollutants and is suitable for waterworks to increase their production. In particular, aquifer temperatures and oxygen supply have a great impact on many microbial processes. To investigate the temporal and spatial behavior of selected organic micropollutants during bank filtration in dependence of relevant biogeochemical conditions, we have set up a 2D reactive transport model using MODFLOW and PHT3D under the user interface ORTI3D. The considered 160-m-long transect ranges from the surface water to a groundwater extraction well of the adjacent waterworks. For this purpose, water levels, temperatures, and chemical parameters were regularly measured in the surface water and groundwater observation wells over one and a half years. To simulate the effect of seasonal temperature variations on microbial mediated degradation, we applied an empirical temperature factor, which yields a strong reduction of the degradation rate at groundwater temperatures below 11 °C. Except for acesulfame, the considered organic micropollutants are substantially degraded along their subsurface flow paths with maximum degradation rates in the range of 1
Extent of the Acidification by N7-Coordinated cis-Diammine-Platinum(II) on the Acidic Sites of Guanine Derivatives
Coordination of two monoprotonated 2'-deoxyguanosine 5'-monophosphate species,
H(dGMP)−, via N7 to cis-(NH2)2Pt2+ gives the complex cis-(NH2)2Pt(H·dGMP)2 which is a four-protonic
acid. The corresponding acidity constants were measured by potentiometric pH titrations
(25℃; I = 0.1 M, NaNO3). The first two protons are released from the two -P(O)2(OH)− groups
(PKa/1= 5.57; PKa/2 = 6.29) and the next two protons are from the H(N1) sites of the guanine
residues (PKa/3 = 8.73; PKa/4 = 9.48). The micro acidity constants of the various sites are also
evaluated. Comparison of these data with those determined for the three-protonic H2(dGMP)± (PKa/1 = 2.69 for the H+(N7) site; PKa/2 = 6.29 for -P(O)2(OH)− ;PKa/3 = 9.56 for H(N1)) shows that
on average the N-7-coordinated Pt2+ acidifies the phosphate protons by Δ pKa = 0.36 and the
H(N1) sites by Δ pKa = 0.46. These results are further compared with those obtained previously for
cis-(NH2)2Pt(L)2, where L = 9-ethylguanine or monoprotonated 2'-deoxycytidine 5'-monophosphate.
Conclusions regarding platinated DNA are also presented
JOKARUS - Design of a compact optical iodine frequency reference for a sounding rocket mission
We present the design of a compact absolute optical frequency reference for
space applications based on hyperfine transitions in molecular iodine with a
targeted fractional frequency instability of better than . It
is based on a micro-integrated extended cavity diode laser with integrated
optical amplifier, fiber pigtailed second harmonic generation wave-guide
modules, and a quasi-monolithic spectroscopy setup with operating electronics.
The instrument described here is scheduled for launch end of 2017 aboard the
TEXUS 54 sounding rocket as an important qualification step towards space
application of iodine frequency references and related technologies. The
payload will operate autonomously and its optical frequency will be compared to
an optical frequency comb during its space flight
BetaHPV E6 and E7 colocalize with NuMa in dividing keratinocytes
Human papillomaviruses (HPVs) of genus betapapillomavirus (betaHPV) are implicated in skin carcinogenesis, but their exact role in keratinocyte transformation is poorly understood. We show an interaction of HPV5 and HPV8 oncoproteins E6 and E7 with the nuclear mitotic apparatus protein 1 (NuMA). Binding of E6 or E7 to NuMA induces little aneuploidy, cell cycle alterations, or aberrant centrosomes. Intracellular localization of NuMA is not altered by E6 and E7 expression in 2D cultures. However, the localization profile is predominantly cytoplasmic in 3D organotypic skin models. Both viral proteins colocalize with NuMA in interphase cells, while only E7 colocalizes with NuMA in mitotic cells. Intriguingly, a small subset of cells shows E7 at only one spindle pole, whereas NuMA is present at both poles. This dissimilar distribution of E7 at the spindle poles may alter cell differentiation, which may in turn be relevant for betaHPV-induced skin carcinogenesis.Peer reviewe
Production Technology Requirements with Respect to Agile Manufacturing - A survey on how the metal forming industry can adapt to volatile times
Agile manufacturing is a production concept that was originally developed at the Iaccoca Institute of Lehigh University (USA). The purpose was to develop a proposal on how the US could regain its supremacy in manufacturing.
The objective of this thesis is to apply the agile manufacturing concept to the metal forming industry and to develop a recommendation of action how the press manufacturers can support their customers in dealing with volatile markets in an efficient way. For that reason production technology requirements are developed that should highlight characteristics of a production line that is essential to become “agile”.
As a point of departure a literature research has been carried out to determine what has already been published about “agile” production requirements and how other industries deal with volatile markets.
In a next step interviews with industry experts have been carried out to verify the findings of the literature review. The findings were documented in case studies which where the basis for the derivation of the production technology requirements that are relevant for the metal forming industr
Impact of river reconstruction on groundwater flow during bank filtration assessed by transient three-dimensional modelling of flow and heat transport
Notice: the article has been corrected and updated.
Use this link for up-to-date information: https://doi.org/10.1007/s10040-019-02063-
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