11,388 research outputs found
Limited Range Fractality of Randomly Adsorbed Rods
Multiple resolution analysis of two dimensional structures composed of
randomly adsorbed penetrable rods, for densities below the percolation
threshold, has been carried out using box-counting functions. It is found that
at relevant resolutions, for box-sizes, , between cutoffs given by the
average rod length and the average inter-rod distance $r_1$, these
systems exhibit apparent fractal behavior. It is shown that unlike the case of
randomly distributed isotropic objects, the upper cutoff $r_1$ is not only a
function of the coverage but also depends on the excluded volume, averaged over
the orientational distribution. Moreover, the apparent fractal dimension also
depends on the orientational distributions of the rods and decreases as it
becomes more anisotropic. For box sizes smaller than the box counting
function is determined by the internal structure of the rods, whether simple or
itself fractal. Two examples are considered - one of regular rods of one
dimensional structure and rods which are trimmed into a Cantor set structure
which are fractals themselves. The models examined are relevant to adsorption
of linear molecules and fibers, liquid crystals, stress induced fractures and
edge imperfections in metal catalysts. We thus obtain a distinction between two
ranges of length scales: where the internal structure of the
adsorbed objects is probed, and where their distribution is
probed, both of which may exhibit fractal behavior. This distinction is
relevant to the large class of systems which exhibit aggregation of a finite
density of fractal-like clusters, which includes surface growth in molecular
beam epitaxy and diffusion-limited-cluster-cluster-aggregation models.Comment: 10 pages, 7 figures. More info available at
http://www.fh.huji.ac.il/~dani/ or
http://www.fiz.huji.ac.il/staff/acc/faculty/biham or
http://chem.ch.huji.ac.il/employee/avnir/iavnir.htm . Accepted for
publication in J. Chem. Phy
Hodge numbers for the cohomology of Calabi-Yau type local systems
We use Higgs cohomology to determine the Hodge numbers of the first
intersection cohomology group of a local system V arising from the third direct
image of a family of Calabi-Yau 3-folds over a smooth, quasi-projective curve.
We give applications to Rhode's families of Calabi-Yau 3-folds without MUM.Comment: Some signs corrected. This article draws heavily from arXiv:0911.027
R Function Related to Entanglement of Formation
By investigating the convex property of the function R, appeared in computing
the entanglement of formation for isotropic states in Phys. Rev. Lett. 85, 2625
(2000), and a tight lower bound of entanglement of formation for arbitrary
bipartite mixed states in Phys. Rev. Lett. 95, 210501 (2005), we show
analytically that the very nice results in these papers are valid not only for
dimensions 2 and 3 but any dimensions.Comment: 3 page
The Effect of Pre-Interview Training and Warnings on Children\u27s Eyewitness Testimonies
The present study examined two important issues regarding children\u27s eyewitness testimonies -compliance which is the tendency to agree with misleading questions and the misinformation effect whereby participants incorporate misleading postevent information into their memory recall of the original event. Eighty six primary school children (6-8 years) watched a video, listened to a misleading narrative and were then interviewed individually. To reduce compliance half the children received a pre-interview training package composed of instructions and practice questions with \u27neither\u27 and \u27don\u27t know\u27 response options. To reduce the misinformation effect children were given a warning that they may have heard some misleading information. The test consisted of five misleading questions, five nonmisleading questions, five control questions and five misled questions. Results indicated that pre-interview training did reduce compliance to misleading questions, however there was also a decrease in correct responses to nonmisleading questions. This may be due to an overgeneralisation of the \u27don\u27t know\u27 and \u27neither\u27 options or a reflection of the high rate of guessing. There was a misinformation effect, indicating that the children did incorporate the misleading information into their answers. The warning did not reduce the misinformation effect for children in the experimental group. This may be due to a lack of cognitive abilities to retrieve the original information and the demand characteristics of the interview situation. A number of explanations for the findings of the study are discussed. Further research would be beneficial investigating ways of improving children\u27s accuracy and reliability when providing eyewitness testimonies
Site Amplification Studies for NPP Sites in Switzerland within the Project Pegasos and PRP
Based on a request by ENSI (Nuclear Regulatory Authority of Switzerland) to update the existing probabilistic earthquake hazard studies, Swissnuclear, the association of the nuclear power plants in Switzerland, initiated the PEAGASOS Project. The project started in 2001 and finished in 2004. It is for Europe a unique study, which aimed to evaluate uncertainties systematically and comprehensively. It was decided to perform the study on SSHAC-level 4. Level 4, defined by the Senior Seismic Hazard-Committee, is the highest level and was used only once before for the Yucca-Mountain-Project in the USA. In the PEGASOS Project, 21 international experts from Europe and additional supporting experts and companies from US and Europe were involved. The project was divided in 4 sub-projects representing the different steps in a seismic hazard assessment, namely seismic source characterization, attenuation relationships models, site amplification and seismic hazard calculation. ENSI closely accompanied and reviewed the project. It concluded that PEGASOS project fulfilled the requirements of a level-4-study. The assessment of site-effects and the innovative quality assurance program has set a new benchmark in seismic hazard assessment. The results have been based on the latest state of knowledge and are the best basis to assess the seismic hazard at the four nuclear power plant sites in Switzerland. It also noticed that the derived uncertainties were remarkably large and could probably be reduced by further investigations. The best candidates for reduction of uncertainties were identified in the area of attenuation models and in the site conditions studies. Therefore Swissnuclear initiated the PEGASOS Refinement Project (PRP). The paper describes in brief the project structure of the PEGASOS and the PRP, the methodology, the sensitivities of the results and the main findings. It discusses the experiences and the lessons learned by one of the site experts. The paper is mainly based on PEGASOS (2004) where more detailed information can be found
Comparative Morphology of the Penis and Clitoris in Four Species of Moles (Talpidae).
The penile and clitoral anatomy of four species of Talpid moles (broad-footed, star-nosed, hairy-tailed, and Japanese shrew moles) were investigated to define penile and clitoral anatomy and to examine the relationship of the clitoral anatomy with the presence or absence of ovotestes. The ovotestis contains ovarian tissue and glandular tissue resembling fetal testicular tissue and can produce androgens. The ovotestis is present in star-nosed and hairy-tailed moles, but not in broad-footed and Japanese shrew moles. Using histology, three-dimensional reconstruction, and morphometric analysis, sexual dimorphism was examined with regard to a nine feature masculine trait score that included perineal appendage length (prepuce), anogenital distance, and presence/absence of bone. The presence/absence of ovotestes was discordant in all four mole species for sex differentiation features. For many sex differentiation features, discordance with ovotestes was observed in at least one mole species. The degree of concordance with ovotestes was highest for hairy-tailed moles and lowest for broad-footed moles. In relationship to phylogenetic clade, sex differentiation features also did not correlate with the similarity/divergence of the features and presence/absence of ovotestes. Hairy-tailed and Japanese shrew moles reside in separated clades, but they exhibit a high degree of congruence. Broad-footed and hairy-tailed moles reside within the same clade but had one of the lowest correlations in features and presence/absence of ovotestes. Thus, phylogenetic affinity and the presence/absence of ovotestes are poor predictors for most sex differentiation features within mole external genitalia
Surface charging of thick porous water ice layers relevant for ion sputtering experiments
We use a laboratory facility to study the sputtering properties of
centimeter-thick porous water ice subjected to the bombardment of ions and
electrons to better understand the formation of exospheres of the icy moons of
Jupiter. Our ice samples are as similar as possible to the expected moon
surfaces but surface charging of the samples during ion irradiation may distort
the experimental results. We therefore monitor the time scales for charging and
dis- charging of the samples when subjected to a beam of ions. These
experiments allow us to derive an electric conductivity of deep porous ice
layers. The results imply that electron irradiation and sputtering play a
non-negligible role for certain plasma conditions at the icy moons of Jupiter.
The observed ion sputtering yields from our ice samples are similar to previous
experiments where compact ice films were sputtered off a micro-balance.Comment: arXiv admin note: text overlap with arXiv:1509.0400
Verification of CPT-invariance of QED bound states for the production of muonium or antimuonium in scattering of electrons or positrons by nuclei
A possibility of a verification of CPT-invariance of QED for bound states by
example of muonium or antimuonium produced in reactions of scattering of
electrons or positrons by nuclei is considered. The number of events of the
muonium production is estimated for contemporary accelerators. The method of
the detection of muonium by measuring of oscillations of the decay curve caused
by the interference between the ground and excited state of muonium is
suggested. The admixture of the excited muonium to the final state is
calculated.Comment: 7 pages, 3 figures, Latex, published in JETP 74, 196 (2001),
corrected mistypes in eqs. (2.2), (2.4), (2.7
Transport and thermoelectric properties of the LaAlO/SrTiO interface
The transport and thermoelectric properties of the interface between
SrTiO and a 26-monolayer thick LaAlO-layer grown at high
oxygen-pressure have been investigated at temperatures from 4.2 K to 100 K and
in magnetic fields up to 18 T. For 4.2 K, two different electron-like
charge carriers originating from two electron channels which contribute to
transport are observed. We probe the contributions of a degenerate and a
non-degenerate band to the thermoelectric power and develop a consistent model
to describe the temperature dependence of the thermoelectric tensor. Anomalies
in the data point to an additional magnetic field dependent scattering.Comment: 7 pages, 4 figure
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