Experimental investigation and CFD simulation of the behaviour of mineral wool in the reactor sump

The investigation of insulation debris generation, transport and sedimentation becomes important with regard to reactor safety research for PWR and BWR, when considering the long-term behavior of emergency core cooling systems during all types of loss of coolant accidents (LOCA). The insulation debris released near the break during a LOCA incident consists of a mixture of disparate particle population that varies with size, shape, consistency and other properties. Some fractions of the released insulation debris can be transported into the reactor sump, where it may perturb/impinge on the emergency core cooling systems. Open questions of generic interest are the sedimentation of the insulation debris in a water pool, its possible re-suspension and transport in the sump water flow and the particle load on strainers and corresponding pressure drop. A joint research project on such questions is being performed in cooperation between the University of Applied Sciences Zittau/Gorlitz and the Forschungszentrum Dresden-Rossendorf. The project deals with the experimental investigation of particle transport phenomena in coolant flow and the development of CFD models for its description. While the experiments are performed at the University at Zittau/Gorlitz, the theoretical modeling efforts are concentrated at Forschungszentrum Dresden-Rossendorf. In the current paper the basic concepts for CFD modeling are described and feasibility studies including the conceptual design of the experiments are presented. Copyright © 2008 by ASME.

Thermobonded Fabrics

In 2009 Avella created a series of innovative fabrics for the Yves St Laurent (YSL) collection, deploying techniques from vehicle engineering to generate new materials for a range of garments. Studying the bonding of layers of material in ceramic plate thermobonding technology, Avella conducted a series of experiments with textiles such as flannel, silk and synthetics, and material such as leather, layered with polyamide foam and textile substrate to create new, textured and insulating fabrics with beautiful surfaces and interesting forms. The lightweight properties of the foam enabled the maximum insulation/weight ratio, and the panel moulding technology brought new forms of draping prêt-a-porter fashion design. Exclusive to YSL, this technique was patented and then shown at the Premiere Vision textiles trade fair in 2010. Much documented in specialist journals this innovation also breached the trade-culture barrier and was reported and documented in mainstream newspapers (New York Herald Tribune). Avella’s background in textile workshop studio experimentation at the RCA brought to YSL textiles research for manufacture, the innovative collaboration between fashion couture and engineering laboratory experiments from vehicle design.

Surface functionalization of textiles with TiO2-based nanocomposites

 Esfandiar’s thesis is entitled “Surface Functionalization of Textiles with TiO2-Based Nano Composites”. Esfandiar introduced some properties such as the self-cleaning, antimicrobial activity, and UV protection to wool and cotton fabrics, analyzing the impact of influential parameters on the obtained results. His research findings arising from his assessment of diverse aspects of fabrics, coated with colloids, have made a contribution to the field by providing a clearer view on the concept of functionalized textiles.

Moisture transfer properties of bifacial fabrics

Many biological plants have bifacial leaves with an adaxial surface and an abaxial surface. These two surfaces can often have different morphologies and properties, and they serve different functions in plant growth. This has inspired us to develop novel bifacial fabrics, with a knitted structure on one face and a woven structure on the other. Bifacial fabrics were produced on a purpose-built machine, using wool, acrylic and polyester yarns, with the woven structure being plain weave, and the knitted structure being single jersey. In this study, the moisture properties of these fabrics were compared with conventional woven and knitted fabrics. The water contact angles of the bifacial fabrics were similar to knitted and woven fabrics, but the absorption time on the woven fabric was much higher than the other fabrics. Liquid moisture transfer properties on both faces of the bifacial fabrics were different, with water spreading and absorption on the woven face being quicker than on the knitted face. These unique properties of bifacial fabrics show that these fabrics could be used as moisture management fabrics, without the need for any additional treatments.

Predicting fabric prickle propensity by testing yarns on the Wool ComfortMeter

The Wool ComfortMeter is the first simple and fast objective tool in the world for assessing wool fabric prickle propensity. IWTO-DTM-66 for the measurement of fabrics using the WCM was accepted at the IWTO Cape Town Congress, South Africa in 2014. Since then, interest has been shown in the technology by yarn manufacturers and buyers for testing yarns before fabric is made, in order to obtain the prickle propensity of a fabric while still at yarn stage.Presentation of the yarn sample to the Wool ComfortMeter is critical. An YG381 yarn winder was selected for this project because it is a fast and reliable tool for sample preparation. The investigation into yarn winding density and tension showed that both the winding density and tension did not significantly affect the tested yarn WCM values. Therefore, a sample preparation protocol was established by using a winding density 19 loops/cm and a 20g tension plate on the YG381 winding machine.Further examination by complying with the preparation protocol showed that yarn Wool ComfortMeter value was the only significant predictor of its corresponding fabric Wool ComfortMeter value. Thus, liner and polynomial regression models were developed for predicting the fabric WCM prickle propensity. Based on the prediction performance, a linear model was recommended for the 1-ply yarns and polynomial model for the 2-ply yarns in this report. The prediction errors were approximately 66 for the 1-ply yarns and 14 for the 2-ply yarns.

Fabric and greasy wool handle, their importance to the Australian wool industry: a review

Handle-related properties of woollen fabrics have been demonstrated to be major factors affecting consumer buying attitudes. Handle is the combination of both textural and compressional attributes. Compressional handle has demonstrated processing advantages in woven and knitted fabrics. The handle of processing lots can be manipulated using a variety of technologies but direct manipulation of textural greasy wool handle pre-processing is still crude. On-farm, there is documented evidence that including handle assessment in a selection index provides additional improvements in genetic gain. However, the assessment of greasy wool handle is based on a tactile evaluation of the wool staple by sheep and wool classers, and its application is affected by a lack of framework that instructs assessors on a standard method of assessment. Once a reliable and repeatable protocol is developed, further understanding of the effect greasy wool handle has on final garment quality will be possible.

Nano titanium dioxide on wool keratin as UV absorber stabilized by butane tetra carboxylic acid (BTCA): a statistical prospect

Photo yellowing of wool is one of the most important problems which have negative impacts on various aspects of wool prompting scientists to find a solution over the past decades. In this research the protective features of nano-titanium dioxide particles against UV on wool fabric were discussed and the color variations of wool samples after UV irradiation were measured and reported. It was shown that nano TiO2 is a suitable UV absorber and its effect depends on the concentration. Also, it was assumed that butane tetracarboxylic acid plays a prominent role as a cross-linking agent to stabilize the nano-titanium dioxide as well as a polyanion to maintain negative charges on the wool surface for higher nano particles absorption. Also the variables conditions were optimized using response surface methodology (RSM).

Reducing photoyellowing of wool using nano TiO2

Wool is the most important animal fiber used in textile industries, but its photostability is very low. Scientists have searched for new ways to increase the photostability of wool. As TiO2 nano particles have features suitable for new applications, the UV-blocking power of nano TiO2 may be used for protecting fabrics against UV rays. Treatment of wool with TiO 2 can be effective for controlling photodegradation. This study focused on protecting wool fabric against UV rays using nano TiO2. To this end, oxidized and raw wool were treated with citric acid as the cross-linking agent and different concentrations of nano TiO2. The whiteness and yellowness of wool fabric samples were reported. XRD patterns proved the existence of TiO2 nano-particles on the wool surface. Finally, the results revealed that nano TiO2 is a suitable UV absorber on wool fabric and its effect depends on concentration.

Lusitanian Amphorae in Carthago Nova (Cartagena, Spain): Distribution and Research Questions

The presence of Lusitanian amphorae in the region of Carthago Nova (Cartagena, Spain) has been known for a few years, and yet it has never been the subject of a monographic study. Integrated in the commercial networks of the western Mediterranean, these products circulated within the harbour system of this city between the 1st and the 5th century AD. This paper aims to present a synthesised review of the main Lusitanian imports that were detected: Dressel 14 and Almagro 50, Almagro 51a-b and Almagro 51c. The difficulty in identifying the ceramic fabrics and the scarce documentation regarding some finds pose complex problems. This study extends to the hinterland of the colony and to other nearby settlements, such as Portmán and Puerto de Mazarrón.

Thermoregulatory response in hair sheep and shorn wool sheep

This study’s main goal was to evaluate the thermoregulatory responses velocity through the variation of rectal temperature (RT), related to the thermolytic pathways, respiratory rate (RR) and sweating rate (SR) among different sheep breeds. Ninety female sheep, eighteen of each breed: Santa Ines and Morada Nova (Brazilian hair breeds), Texel, Suffolk and Ile de France (wool breeds) were challenged during three non-consecutive summer days (22◦42′S, 47◦18′W, and 570m of altitude, maximum air temperature of 33.5◦C, average relative humidity of 52±6.9%). The physiological variables were registered at 0800h (T1), 1300 h (T2: after 2 h of shade rest), 1400 h (T3) (after one hour of sun exposure) and in the shade at 1415 h (T4), 1430 h (T5), 1445 h (T6) and 1500 h (T7) and a thermotolerance index (TCI) was calculated as (10-(T7 to T4)-T1). The statistical analysis was performed by a mathematical model including the fixed effects of breeds and time frames, and the interaction between these effects, besides random effects such as animal and day. The Santa Ines breed presented the lowest RT after sun exposure (39.3 ± 0.12 ◦ C; P < 0.05) and it was the only one to recover morning RT 60 min after heat stress (38.7 and 38.9 for 1300 h and 1500 h; P > 0.05). Hair breeds presented RR lower (P < 0.05) than wool breeds. Although thick wool or hair thickness differs among and within hair and wool breeds (P < 0.05), SR did not differ among breeds and time (227.7 ± 16.44 g m−2 h−1 ; P > 0.05). The thermotolerance index did not differ among breeds, but it showed similar response (P > 0.05) 45 min or 1 h of shade after sun exposure. One week post shearing is not enough to wool breeds present to show thermotolerance similar to hair breeds.