40 research outputs found
The T2K ND280 Off-Axis Pi-Zero Detector
The Pi-Zero detector (P{\O}D) is one of the subdetectors that makes up the
off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino
experiment. The primary goal for the P{\O}D is to measure the relevant cross
sections for neutrino interactions that generate pi-zero's, especially the
cross section for neutral current pi-zero interactions, which are one of the
dominant sources of background to the electron neutrino appearance signal in
T2K. The P{\O}D is composed of layers of plastic scintillator alternating with
water bags and brass sheets or lead sheets and is one of the first detectors to
use Multi-Pixel Photon Counters (MPPCs) on a large scale.Comment: 17 pages, submitted to NIM
A Simple Statistical Mechanical Approach for Studying Multilayer Adsorption of Interacting Polyatomics
A simple statistical mechanical approach for studying multilayer adsorption
of interacting polyatomic adsorbates (k-mers) has been presented. The new
theoretical framework has been developed on a generalization in the spirit of
the lattice-gas model and the classical Bragg-Williams (BWA) and quasi-chemical
(QCA) approximations. The derivation of the equilibrium equations allows the
extension of the well-known Brunauer-Emmet-Teller (BET) isotherm to more
complex systems. The formalism reproduces the classical theory for monomers,
leads to the exact statistical thermodynamics of interacting k-mers adsorbed in
one dimension, and provides a close approximation for two-dimensional systems
accounting multisite occupancy and lateral interactions in the first layer.
Comparisons between analytical data and Monte Carlo simulations were performed
in order to test the validity of the theoretical model. The study showed that:
(i) the resulting thermodynamic description obtained from QCA is significantly
better than that obtained from BWA and still mathematically handable; (ii) for
non-interacting k-mers, the BET equation leads to an underestimate of the true
monolayer volume; (iii) attractive lateral interactions compensate the effect
of the multisite occupancy and the monolayer volume predicted by BET equation
agrees very well with the corresponding true value; and (iv) repulsive
couplings between the admolecules hamper the formation of the monolayer and the
BET results are not good (even worse than those obtained in the non-interacting
case).Comment: 38 pages, 12 figure
Endometriosis Index: A Software-Derived Score to Predict the Presence and Severity of the Disease
Blastocyst development in an extended embryo culture system after intracytoplasmic sperm injection
EQUSUM: Endometriosis QUality and grading instrument for SUrgical performance: proof of concept study for automatic digital registration and clssification scoring for r-ASRM, EFI and Enzian
Action Contro
Measurement of specific fracture energy and surface tension of brittle materials in powder form
V článku uvedeno Libor M. Hlaváč.This article presents a method for the experimental measurement of specific fracture energy and surface tension of a brittle materials in a powder form. This work is focused on testing a method on the mineral, almandine. A hydraulic press was used in the experiment to crush powder particles, and statistical evaluation was used to analyze the change in the powder surface. The powder was subject to various conditions during crushing. The crushing was performed both in air and in water. It was done at three different compression speeds, namely 15.8 MPa/s, 3.95 MPa/s and 2.25 MPa/s. The experimental results showed measurable differences in the specific fracture energy values in the presented regimes