Naturaleza de ciertas manchas que aparecen en tejidos de lana

En el curso de este trabajo, se inicia el estudio sobre la naturaleza de determinadas manchas que aparecen en artículos de lanería de señora, fabricados con mezcla de puncha y lana. Se determina cual de las materias que intervienen, es el origen de la aparición de las manchas, así como las características más sobresalientes de las fibras que las motivan. Finalmente se efectúa el primer paso en la investigación del origen y naturaleza de las mismas.Peer Reviewe

Naturaleza de ciertas manchas que aparecen en tejidos de lana

La presencia de ciertas manchas que aparecen en determinados artículos de lana, es motivada por la existencia de fibras coloreadas en el vellón del cordero, las cuales no se encuentran localizadas en determinadas zonas del vellón. La coloración de las fibras se produce tanto por causas de tipo exógeno como por causas endógenas. Al proceder a la identificación del origen de la coloración según las reacciones propuestas por Seddon, se ha encontrado la presencia de cobre en las fibras verdes y ligeras trazas de hierro en las rojas, no habiéndose podido determinar el origen de las fibras azules. La coloración de las fibras, sólo ha podido ser eliminada de forma permanente, mediante tratamiento con soluciones oxidantes de composición similar a las empleadas en el blanqueo de la lana.Peer Reviewe

Environmental knowledge management: A long-term enabler of tourism development

A review of the literature confirms that there is a need for knowledge management frameworks which support knowledge creation, particularly in those organisations having to operate in a changing environment. Socialisation, externalisation, combination and internalisation continue to be key processes for the creation of knowledge which enables organisations to successfully address environmental challenges. This paper examines the relevance and importance of a SECI model as an enabler of the processes of reusing and updating the environmental knowledge of an organisation. The research reported has confirmed that time is a key component of the implementation of a SECI model in organisations operating in a changing environment. Thins been confirmed that such a strategy should focus on the reuse of prior environmental knowledge as a mechanism to establish within the organisation a context where new knowledge management processes are understood and adopted by employees. The paper also examines the relationship between environmental knowledge and organisational performance indicators. These relationships are examined through an empirical study of 87 companies in the Spanish hospitality sector. The results of the study indicate that environmental knowledge at any given time (T) is significant in predicting the knowledge management processes that may be successfully implemented at a later point in time (T + 6 years). (C) 2015 Elsevier Ltd. All rights reserved

Estudio comparativo del blanqueo de la lana por los procedimientos de inmersión e impregnación-vaporizado.

El presente estudio ha tenido por objeto el conocimiento de la mejora del blanco experimentada por dos lanas de diferente coloración cuando se las somete a un blanqueo mixto continuo en una instalación piloto de tipo industrial, efectuando el blanqueo oxidante por el sistema de impregnación-vaporizado y el reductor en los compartimentos de la máquina destinados a tratamientos de lavado o posteriores. Los resultados obtenidos se han comparado con los que se derivan de la aplicación del blanqueo mixto discontinuo convencional, deduciéndose que el blanqueo mixto continuo proporciona blancos iguales o algo inferiores, según el grado de coloración de la lana inicial, degradaciones químicas inferiores, y evidentes ahorros en el consumo de productos, agua y energía térmica.This paper deals with the improvement of whiteness achieved by two kinds of wool, having different colouration, when they are submitted to a continuous and combined bleaching in an industrial pilot unit. The oxidizing bleaching is applied according to the pad-steam method and the reducing one takes place in the boxes of the machine provided for washing or post-treatments. The results found have been compared to the resulting ones from the application of a conventional noncontinuous and combined bleaching: the former provides similar or somewhat lower whiteness, according to the colouration degree of the initial wool, lower chemical degradation and an obvious economy in the consumption of water, heat power and chemicals.La présente étude a eu pour objet la connaissance de l'amélioration du blanc expérimentée par deux laines de différente coloration lorqu'on les soumet à un blanchissage mixte continu dans unes installation pilote industrielle en effectuant le blanchissage oxydant par le systeme imprégnation-vaporisage et celui réducteur dans les compartiments de la machine destinés a des traitements de lavage ou postérieurs. On a comparé les résultats obtenus avec ceux qui dérivent de l'application du blanchissage mixte discontinu conventionnel; on a pu en déduire que dans le blanchissage mixte continu les blancs sont égaux ou un peu inférieurs á ceux du blanchissage mixte discontinu, selon le degré de coloration de la laine initial, que les dégradations chimiques sont inférieures et que l'on réalise des économies évidentes de consommation de produits, d'eau et d'énergie thermique et électrique.Peer Reviewe

Comparative analysis of two selective bleaching methods on alpaca fibers

Dark brown Alpaca fiber was reduced in shade via selective bleaching with peroxide. Two selective oxidative bleaching methods were tested on alpaca top to assess their effectiveness for color removal and fiber quality properties. Color change, bundle strength, weight loss, fiber diameter, surface modification, dye-ability and dye wash fastness were assessed for both methods and compared with the original brown top. Bleach method 1 (BL-I) showed little surface modification, 5.8 % weight loss and 2.4 % strength loss. D1925 yellowness index was reduced to 74.3 from 83.1 and provided a good base for the dyeing of medium to deep shades. Bleach method 2 (BL-II) displayed considerable surface modification, 7.8 % weight loss and 18 % strength loss. BL-II also resulted in a mean diameter reduction of 1.9 micron during bleaching. Yellow-ness was reduced to 64.5 from 83.1 and provided a very good base for the dyeing of medium to deep shades. BL-I showed better exhaustion of the pre-metallised dye Lanaset Violet B than BL-II. Wash fastness for BL-II was 1 grey scale unit poorer than BL-I. BL-II showed far better color clarity at pale depths however the wash fastness of the finished product was not good enough to maintain the depth or clarity of the color. BL-I showed poorer clarity of color but exhibited better wash fastness results. <br /

Effects of bleaching and dyeing on the quality of alpaca tops and yarns

This paper reports the effects of bleaching of alpaca tops and dyeing of bleached alpaca tops/yarns on the quality of tops and yarns. A dark brown alpaca top was bleached with hydrogen peroxide. Two bleaching methods were tried for effectiveness of color removal. A portion of each bleached top was dyed after bleaching. Color parameters were examined for unbleached, bleached and bleached/dyed tops, these tops were then converted into yarns of different twist levels and counts using a worsted spinning system. Some of the bleached yarn from each bleaching method was dyed in a package dye vat to compare the difference of top dyeing versus yarn package dyeing on yarn quality. Fiber diameter, yarn strength, yarn evenness, yarn hairiness and fiber degradation were tested to examine the effects of bleaching and dyeing on these properties at top and yarn stages. A processing route for bleaching and dyeing alpaca fiber was recommended. <br /

From double Lie groupoids to local Lie 2-groupoids

We apply the bar construction to the nerve of a double Lie groupoid to obtain a local Lie 2-groupoid. As an application, we recover Haefliger's fundamental groupoid from the fundamental double groupoid of a Lie groupoid. In the case of a symplectic double groupoid, we study the induced closed 2-form on the associated local Lie 2-groupoid, which leads us to propose a definition of a symplectic 2-groupoid.Comment: 23 pages, a few minor changes, including a correction to Lemma 6.