987 research outputs found
Applications of fibrous substrates containing insolubilized phase change polymers
Incorporation of polyethylene glycols into fibrous substrates produces several improved functional properties when they are insolubilized by crosslinking with a methylolamide resin or by polyacetal formation by their reaction with glyoxal. The range of molecular weights of polyols that may be insolubilized is broad as are the curing conditions (0.25-10 min at 80-200C). Most representative fiber types and blends (natural and synthetic) and all types of fabric constructions (woven, nonwoven and knit) have been modified by incorporation of the bound polyols. The most novel property is the thermal adaptability of the modified substrates to many climatic conditions. This adaptability is due to the high latent heat of the crosslinked polyols that function as phase change materials, the hydrophilic nature of the crosslinked polymer and its enhanced thermal conductivity. Other enhanced properties imparted to fabrics include flex and flat abrasion, antimicrobial activity, reduced static charge, resistance to oily soils, resiliency, wind resistance and reduced lint loss. Applications commercialized in the U.S. and Japan include sportswear and skiwear. Several examples of electric sets of properties useful for specific end uses are given. In addition, other uses are biomedical horticultural, aerospace, indoor insulation, automotive interiors and components and packaging material
A new approach for the ortho-positronium lifetime determination in a vacuum cavity
Currently, the experimental uncertainty for the determination of the
ortho-positronium (o-Ps) decay rate is at 150 ppm precision; this is two orders
of magnitude lower than the theoretical one, at 1 ppm level. Here we propose a
new proof of concept experiment aiming for an accuracy of 100 ppm to be able to
test the second-order correction in the calculations, which is ppm. The improvement relies on
a new technique to confine the o-Ps in a vacuum cavity. Moreover, a new method
was developed to subtract the time dependent pick-off annihilation rate of the
fast backscattered positronium from the o-Ps decay rate prior to fitting the
distribution. Therefore, this measurement will be free from the systematic
errors present in the previous experiments. The same experimental setup
developed for our recent search for invisible decay of ortho-positronium is
being used. The precision will be limited by the statistical uncertainty, thus,
if the expectations are fulfilled, this experiment could pave the way to reach
the ultimate accuracy of a few ppm level to confirm or confront directly the
higher order QED corrections. This will provide a sensitive test for new
physics, e.g. a discrepancy between theoretical prediction and measurements
could hint the existence of an hidden sector which is a possible dark matter
candidate.Comment: 12 pages, 8 Figures, prepared for the proceedings of the PSAS2018
conference, Vienna (Austria
Owner and animal factors predict the incidence of, and owner reaction towards, problem behaviors in companion dogs
Unwelcome behaviors in pet dogs may have serious implications for the quality of life of both the animals and their owners. We investigated owners\u2019 perceptions about their dogs\u2019 behavioral issues as well as other factors that might be predictive of potential canine problem behaviors. We distinguished between \u201cundesirable behaviors\u201d (behaviors that were unpleasant to the owners) and \u201cproblematic behaviors\u201d (behaviors that the owners found difficult to overcome). We designed an on-line survey eliciting information about owners, their dogs, their relationship with their dogs and whether the animals exhibited any of 15 potentially problematic behaviors. The largest proportion of respondents (65%) reported that their dogs exhibited undesirable, but not problematic, behaviors and were not interested in their modification. Only 32% of the respondents considered the behavior to be both undesirable and problematic and wished to change it. The owners\u2019 perception of a problem was associated with reports of fear- and anxiety-related behaviors. The owner\u2019s gender, marital status and attitude towards the dog as his/her child as well as the dog\u2019s age, size, age at acquisition and breed emerged as robust predictors. Compared to all other behavioral categories, reported aggressive canine behaviors were three times more likely to elicit an owner\u2019s wish to address them. This study revealed that the behaviors of dogs may be perceived differently by their owners and the type of perception may influence the owner\u2019s actual willingness to change those behaviors. Moreover, we identified the most robust set of factors that, either individually or combined, would help predict a dog\u2019s potential problem behaviors and an owner\u2019s attitude towards them, which will be useful in improving rational prevention and treatment strategies
Gender Differences in Health-Related Physical Fitness Among College Students
Please refer to the pdf version of the abstract located adjacent to the title
Intense beam of metastable Muonium
Precision spectroscopy of the Muonium Lamb shift and fine structure requires
a robust source of 2S Muonium. To date, the beam-foil technique is the only
demonstrated method for creating such a beam in vacuum. Previous experiments
using this technique were statistics limited, and new measurements would
benefit tremendously from the efficient 2S production at a low energy muon
( keV) facility. Such a source of abundant low energy has
only become available in recent years, e.g. at the Low-Energy Muon beamline at
the Paul Scherrer Institute. Using this source, we report on the successful
creation of an intense, directed beam of metastable Muonium. We find that even
though the theoretical Muonium fraction is maximal in the low energy range of
keV, scattering by the foil and transport characteristics of the beamline
favor slightly higher energies of keV. We estimate that
an event detection rate of a few events per second for a future Lamb shift
measurement is feasible, enabling an increase in precision by two orders of
magnitude over previous determinations
Provisiones, regalos, cohechos y préstamos: la Informaçion Original de 1588 y la defensa de la autoridad virreinal en el Perú del siglo XVI
Studies on the authority of viceroys in America, their conflicts at the local level, accusations of bad government and the mechanisms to control their performance have shed new light on the nature of viceregal political order, the scope and limits of monarchical power and the dynamics of constant negotiation carried on. This article analyzes the Informaçión Original accomplished in 1588 by conde del Villar, viceroy of Peru, which, beyond a self-examination, was a strategy to rebuild his authority and image as a legitimate political actor in the Peruvian scene.Los estudios en torno a la autoridad de los virreyes en América, sus conflictos a nivel local, las acusaciones de mal gobierno y los mecanismos para controlar su desempeño han dado nuevas luces sobre la naturaleza del orden político virreinal, los alcances y límites del poder monárquico y la dinámica de constante negociación puesta. Este artículo analiza la Informaçión Original llevada a cabo en 1588 por el conde del Villar, virrey del Perú, que más allá de una auto fiscalización, fue una estrategia para recomponer su autoridad e imagen como actor político legítimo en el escenario peruano
The two-echelon capacitated vehicle routing problem: models and math-based heuristics
Multiechelon distribution systems are quite common in supply-chain and logistics. They are used by public administrations in their transportation and traffic planning strategies, as well as by companies, to model own distribution systems. In the literature, most of the studies address issues relating to the movement of flows throughout the system from their origins to their final destinations. Another recent trend is to focus on the management of the vehicle fleets required to provide transportation among different echelons. The aim of this paper is twofold. First, it introduces the family of two-echelon vehicle routing problems (VRPs), a term that broadly covers such settings, where the delivery from one or more depots to customers is managed by routing and consolidating freight through intermediate depots. Second, it considers in detail the basic version of two-echelon VRPs, the two-echelon capacitated VRP, which is an extension of the classical VRP in which the delivery is compulsorily delivered through intermediate depots, named satellites. A mathematical model for two-echelon capacitated VRP, some valid inequalities, and two math-heuristics based on the model are presented. Computational results of up to 50 customers and four satellites show the effectiveness of the methods developed
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