334 research outputs found
The Use of Activity Chain Models to Analyse Stochastic Travel Demand
For analysis and planing of transport networks detailed information concerning travel sequences is required. The paper examines an activity chain model to determine stochastic travel demand which individual generates in order to participate in activity or sequence of activities over the day. The transition from one activity to another depends on the activity participation decision, which is made sequentially and is constrained in space and time. Activity chains derived from travel survey data are used as a base to develop a more realistic model than conventional discrete trip models. Probabilistic concepts and statistical procedures are used to estimate characteristics of travel demand such as the number of daily out-of-home activities and transition probability from one activity to another participated by homogeneous behavioural groups. In addition, the paper compares the model for two different sized towns
Magnetic properties of small Pt-capped Fe, Co and Ni clusters: A density functional theory study
Theoretical studies on M (M = Fe, Co, Ni) and MPt (for
= 3, 4, 5, 20) clusters including the spin-orbit coupling are done using
density functional theory. The magnetic anisotropy energy (MAE) along with the
spin and orbital moments are calculated for M icosahedral clusters. The
angle-dependent energy differences are modelled using an extended classical
Heisenberg model with local anisotropies. From our studies, the MAE for
Jahn-Teller distorted Fe, Mackay distorted Fe and nearly
undistorted Co clusters are found to be 322, 60 and 5 eV/atom,
respectively, and are large relative to the corresponding bulk values, (which
are 1.4 and 1.3 eV/atom for bcc Fe and fcc Co, respectively.) However, for
Ni (which practically does not show relaxation tendencies), the
calculated value of MAE is found to be 0.64 eV/atom, which is
approximately four times smaller compared to the bulk fcc Ni (2.7
eV/atom). In addition, MAE of the capped cluster (FePt) is
enhanced compared to the uncapped Jahn-Teller distorted Fe cluster
Peptide-Grafted Nontoxic Cyclodextrins and Nanoparticles against Bacteriophage Infections
One of the biggest threats for bacteria-based bioreactors in the biotechnology industry is infections caused by bacterial viruses called bacteriophages. More than 70% of companies admitted to encountering this problem. Despite phage infections being such a dangerous and widespread risk, to date, there are no effective methods to avoid them. Here we present a peptide-grafted compounds that irreversibly deactivate bacteriophages and remain safe for bacteria and mammalian cells. The active compounds consist of a core (cyclodextrin or gold nanoparticle) coated with a hydrophobic chain terminated with a peptide selective for bacteriophages. Such peptides were selected via a phage display technique. This approach enables irreversible deactivation of the wide range of T-like phages (including the most dangerous in phage infections, phage T1) at 37 degrees C in 1 h. We show that our compounds can be used directly inside the environment of the bioreactor, but they are also a safe additive to stocks of antibiotics and expression inducers (such as isopropyl beta-D-1-thiogalactopyranoside, i.e., IPTG) that cannot be autoclaved and are a common source of phage infections
SPHERES, J\"ulich's High-Flux Neutron Backscattering Spectrometer at FRM II
SPHERES (SPectrometer with High Energy RESolution) is a third-generation
neutron backscattering spectrometer, located at the 20 MW German neutron source
FRM II and operated by the Juelich Centre for Neutron Science. It offers an
energy resolution (fwhm) better than 0.65 micro-eV, a dynamic range of +-31
micro-eV, and a signal-to-noise ratio of up to 1750:1.Comment: 12 pages, 7 figures, 2 tables. Supplemental material consists of 3
pages, 2 figures, 2 table
Radon transform and pattern functions in quantum tomography
The two-dimensional Radon transform of the Wigner quasiprobability is
introduced in canonical form and the functions playing a role in its inversion
are discussed. The transformation properties of this Radon transform with
respect to displacement and squeezing of states are studied and it is shown
that the last is equivalent to a symplectic transformation of the variables of
the Radon transform with the contragredient matrix to the transformation of the
variables in the Wigner quasiprobability. The reconstruction of the density
operator from the Radon transform and the direct reconstruction of its
Fock-state matrix elements and of its normally ordered moments are discussed.
It is found that for finite-order moments the integration over the angle can be
reduced to a finite sum over a discrete set of angles. The reconstruction of
the Fock-state matrix elements from the normally ordered moments leads to a new
representation of the pattern functions by convergent series over even or odd
Hermite polynomials which is appropriate for practical calculations. The
structure of the pattern functions as first derivatives of the products of
normalizable and nonnormalizable eigenfunctions to the number operator is
considered from the point of view of this new representation.Comment: To appear on Journal of Modern Optics.Submitted t
Charakterisierung der Submicron-Partikel in einem umweltrelevanten Wasser: Stauwasser in einer Kommunalmülldeponie über einem Schlammteich (Tailing) der Uranerzaufbereitung in Freital/Sachsen
Characterization of Submicron Particles in an Environmentally-Relevant Water: Backwater From a Sanitary Landfill on a Uranium Mine Tailing at Freital, Saxony. A strategy for characterizing submicron particles in environmental waters based on filtration, centrifugation and photon correlation spectroscopy (PCS) is proposed. Filtration and centrifugation are not used here as methods for particle characterization but serve merely as techniques of a rough separation of the sample. They are applied as cautiously and non-invasively as possible and are only aimed at separating the sample sufficiently for measurements by primarily PCS. The separation should unmask small particles that scatter little light and divide the sample into populations of particles that have monomodal or bimodal size distributions. In this way, the strategy optimizes subsequent particle-size determinations by PCS and minimizes the influence of sample preparation on the samples. A further essential feature of this strategy is the parallel application of complementary methods for both sample preparation and particle characterization (filtration/centrifugation, PCS/SEM, gravimetry/ICP-MS etc.). This facilitates the validation of results and increases the probability for recognizing artifacts. Based on our experimental experience, a guideline for PCS measurements on low-concentration colloids with the BI 90/Correlator BI 9000 AT system from Brookhaven Instruments Corp. was developed. This guideline is aimed at obtaining autocorrelation functions of sufficiently good photon counting statistics which is crucial in PCS on colloidal solutions poor in particles. A measuring campaign on an environmentally-relevant water (backwater from a sanitary landfill on a uranium mine tailing at Freital, Saxony) showed the presence of about 1 to 2 mg/l of submicron particles having a particle size of 30 to 300 nm and of about 5 mg/l of suspended matter (>1000 nm)
The Grizzly, April 10, 1987
Pfahler Hall Flooded • L.C.B. Visits a Second Time • Our Town Debuts • Letters: Director of Security at Sheraton Responds to Student Attack on Lorelei; Brothers of AXE Commended; Grizzly Dogged • Skunked Again • Students to Participate in Model UN Conference • Salamanca to Relate Experiences on Terrorism • Bard Graces Ursinus • Notes: UC / St. Joseph\u27s Host MBA Summer Session; Myrin Holds Semi-Annual Book Sale; New Resident Assistants Announced • Athlete of the Week: Kim Wentzel • Santangelo, O\u27Malley Jump Lady Bears to 6-0 Start • Women\u27s Tennis Served Tough Losses • Track\u27s Record: Record Breaking • Ursinus\u27 Champion Lacrosse Team: Vying for Fourth National Title • Opposition Unfavorable to Bears • Golf Team Drives Record to 8-0 • Softball Assumes First Place Position • Room Selection to Start • The Joshua Tree Rates an A • Young Democrats: Exhibiting New Challenges for the Future • Advanced TV Class Produces Ursinus Magazine For Cable Network • Arbor Day Trees Grow Money • Bear Facts: Ursinus Mascot Bearly Knownhttps://digitalcommons.ursinus.edu/grizzlynews/1187/thumbnail.jp
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