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Influence of Fabric Constructional Parameters and Thread Colour on UV Radiation Protection

Gabrijelčič H., Urbas R., Sluga F., Dimitrovski K.

Fibres & Textiles in Eastern Europe

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2009

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Vol. 17, no. 1 (72)

46--54

EN

The purpose of the research presented was to analyse the influence of the fabric surface cover factor and fabric colour values on the degree of UV ray transmittance and the UV protective factor (UPF). The research was carried out on lightweight coloured fabrics woven in sateen weave with different densities of warp and weft threads and with different colours in the weft. Measurements of the UPF were performed using the “in vitro” method in the range of UVA and UVB ray wavelengths, from 280 to 400 nm. The results of the research confirm the importance of the fabric surface openness for the UV protective factor and expose the influence of the fabric face and reverse sides as well as of colour values L*, C*ab, hab of warp and weft threads on the UPF in sufficiently closed woven constructions. Namely, constructions with less than the 5% surface openness offer excellent protection (UPF above 50), whereas constructions with less than 10% surface openness offer good to very good protection (a UPF above 20). At coverage higher than 95%, the fabrics analysed could be generally divided into three groups with respect to the effectiveness of their UV protection: fabrics of darker colours (black, blue) with extremely high UPF values, fabrics of chromatic lighter colours (yellow, red, green) with UPF values half of those of darker colours in general, and white fabrics (bleached) in which the desired UPF values are not reached regardless of the degree of the cover factor.

PL

Celem badań była analiza wpływu współczynnika wypełnienia powierzchniowego oraz kolorystyki tkaniny na przepuszczalność promieniowania UV i współczynnik ochrony (UPF) przed tym promieniowaniem. Badano tkaniny o małej masie powierzchniowej, o splocie atłasowym o różnej gęstości nitek osnowy i wątku oraz różnym kolorze nitek wątku. Mierzono współczynnik UPF metodą „in vitro” w zakresie promieniowania UVA i UVB, tzn. dla długości fal od 280 do 400nm. Wyniki badań potwierdziły dla tkanin dostatecznie zwartych, istotne znaczenie współczynnika wypełnienia tkaniny dla zabezpieczenia przed promieniowaniem UV oraz pozwoliły określić wpływ współczynnika strukturalnego tkaniny, struktur tkaniny od strony padania promieniowania i strony przeciwnej, oraz walorów kolorystycznych nitek osnowy i wątku, określonych poprzez parametry L*, C*ab, hab. na współczynnik UPF. Przy poniżej 5% nie pokrytej nitkami powierzchni tkaniny, otrzymujemy świetne zabezpieczenie (UPF>50), a przy<10% dobre lub bardzo dobre (UPF>20). Przy współczynniku pokrycia > 95%, tkaniny można podzielć na ciemne (czarne, niebieskie) o ekstremalnie dużym UPF, o jaśniejszych kolorach (żółty, zielony, czerwony) o UPF na ogół mniejszym o połowę niż dla tkanin ciemnych i białe lub bielone, dla których osiągnięcie efektu zabezpieczenia, przy rozważanym wypełnieniu jest niemożliwe.

2

Wpływ wybranych czynników na wykorzystanie mocy nominalnej elektrowni wiatrowej i wskaźniki ekonomiczne produkcji energii

Gumuła A., Stanisz K., Woźniak A.

Systems : journal of transdisciplinary systems science

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2008

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Vol. 13, spec. iss. 1/2

186--193

EN

The influence of the constructional parameters as well as the conditions of work of the wind power station on the economical rates of the production of energy were analysed in this paper. The constructional parameters were the following: the diameter of the rotor of the power station, the height of gondola (the axis of the rotor),the power of the installed generator (the installed power). Among the conditions of work the medium-annual wind speed was taken into account the size of production of energy was also considered, treating the following dimensions as the variable parameters when the remaining sizes were solid. After composition of size of the production of energy for some cases, the economical analysis was conduce The time of return of investment in the wind power station was also estimated, accepting the current prices of energy.

3

Wytyczne konstrukcyjno-eksploatacyjne dla systemów wykorzystujących pompę ciepła do ogrzewania obiektów ogrodniczych

Kurpaska S.

Inżynieria Rolnicza

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2008

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R. 12, nr 2(100)

155-162

PL

W pracy na podstawie wykonanych serii doświadczeń, opracowano nomogramy do określania parametrów konstrukcyjno-eksploatacyjnych systemów mono i biwalentnych wykorzystujących pompę ciepła do ogrzewania obiektów ogrodniczych. W nomogramie dla systemu biwalentnego, w zależności od sumy promieniowania słonecznego przedstawiono graficznie ilość ciepła zmagazynowanego w zbiorniku akumulacyjnym, zmniejszenie temperatury wody podczas pracy pompy ciepła oraz ilość dostarczonego ciepła do wnętrza obiektu ogrodniczego. Z kolei, dla systemu monowalentnego zobrazowano graficznie zapotrzebowanie mocy grzewczej kotła dla rozpatrywanego obiektu, moc ciepła wytwarzaną przez pompę grzewczą wraz wymaganą długością wymienników poziomych oraz liczbę odwiertów dla wymienników pionowych.

EN

On the basis of a series experiments performed, nomograms for determining constructional and operational parameters of monovalent and bivalent systems, using a heat pump to heat horticultural objects, have been developed. In the nomogram for the bivalent system, depending on the sum of the solar radiation, the amount of heat stored in an accumulation tank, the decrease in the temperature of water during pump operation and the amount of heat supplied to the interior of the horticultural object, have been graphically presented. For the monovalent system the heating power required by the boiler in the discussed horticultural object, thermal power produced by the heat pump, together with the required length of horizontal exchangers, and the number of boreholes for vertical exchangers have been graphically presented.

4

Correction of colour values of woven fabrics using changes to constructional parameters

Dimitrovski K., Gabrijelčič H.

Autex Research Journal

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2004

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Vol. 4, no. 4

186--192

EN

In practice it happens very frequently that yarn of certain fineness, which creates desired colour effect on the woven fabrics surface, is not available. In consequence an available yarn of different fineness has to be used instead, which can be observed on the woven fabrics as a colour deviation compared with the desired effect. The aim of this research is the possibility of colour values corrections of woven fabrics by changes of constructional parameters. Simulations of woven fabrics are used for this purpose. In the case described weft the yarn of higher fineness is substituted by the yarn of lower fineness and equal colour values. Three possible ways of colour values correction by changes of constructional parameters of the woven fabric are presented. In the first case, the colour difference is corrected by increase of the weft threads density, the second way of correction consists in the change of warp yarn fineness, and the third in decreasing of warp threads density. The basic purpose of all the three types of correction is the equally change of warp and weft contents in one colour rapport of the woven structure. In the experimental part of our work, the colour values L*, a* and b*, and colour differences DE*ab are investigated theoretically (using calculations on the basis of theoretical defined fractions, and L*, a*, and b* values of yarns), as well as spectrophotometrically, on the basis of printouts of simulations of woven fabrics prepared with the use of Arahne CAD system. Two ways of determination of colour values of simulations and three types of corrections are evaluated in the conclusions. It was find out that the correction with the increase of weft thread density is the most successful, and the DE*ab values are minimal.

5

Statistical method of verification significance of constructional parameters machine tool spindle units

Wolny R.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2002

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z. 58 [193]

331-339

EN

The paper discusses the problem of the significance of the design parameters of a machine tool spindle unit. A computational method has been developed that enables the significance of the design parameters of any arbitrary variant of a machine tool spindle unit to be determined. For the separation of the design parameters, statistical methods were employed, which are used in experimental studies. An analysis of the significance of the design parameters was performed for the model of the spindle unit of a medium-size machine tool.