7,487 research outputs found
The Potential Use of Organically Grown Dye Plants in the Organic Textile Industry: Experiences and Results on Cultivation and Yields of Dyers Chamomile (Anthemis tinctoria L.), Dyers Knotweed (Polygonum tinctorium Ait.) and Weld (Reseda luteola L.)
The organic cultivation of dye plants for the certified natural textiles industry is an emerging and promising sector of organic farming. In 1999 a field trial was done with different provenances of Dyer’s Chamomile (Anthemis tinctoria L.), Dyer’s Knotweed Polygonum tinctorium Ait.), and Weld (Reseda luteola L.) on two organic farms in Lower Austria. Yields, dyestuff content, and quality parameters were analyzed. Dry matter yields of Weld ranged between 0.7 and 2.7 t ha-1, of Dyer’s Chamomile (flower heads) between 1.1 and 1.8 t ha-1. Significant differences were found between seed Weld provenances as well as between those of Dyer’s Chamomile. The total leaf dry matter of Dyer’s Knotweed (2 cuts) ranged at both sites on average 3.1 t ha-1. Seed provenances did not show differences. The total flavonoid content of Weld ranged between 1.53 and 4.00%, of Dyer’s Chamomile between 0.84 and 1.5%. The content of indican in Dyer’s Knotweed ranged between 0.50 and 1.45% of leaf dry matter, the calculated theoretical content of indigo ranged between 0.22 and 0.64% of leaf dry matter. The general use fastness properties differ according to species and provenance. Both high and low values were achieved. The data on the cultivation of dye plants in organic farming show promising results. Research should address improvement in yields and quality, development of dyestuff extracts, and optimization of dyeing methods. Research on dye plants needs a systemic look at the whole chain including producers, processors, trade,
and consumers
Dry matter and fibre yields, and the fibre characteristics of five nettle clones (Urtica dioica L.) organically grown in Austria for potential textile use
The aim of the field trial was to quantifiy yield, fibre content and fibre quality of 5 fibre nettle clones cultivated according to the principles of organic farming. The field trial started in 1997 and was organized in a randomised block design with 4 replications per clone. The field trial was situated in Neulengbach, Lower Austria. Since fibre nettle does not provide sufficient yields in the first cultivation year, the harvest of the second and third cultivation year (1998 respectively 1999) was used for calculation of yield per hectar and for the analysis of fibre content and quality.
The dry matter yield (stalks) of the 5 nettle clones in the second cultivation year (1998) lies between 2,3 – 4,7 t/ha. Clone 1 and Clone 7 achieve the highest yields. This result was statistically significant. The dry matter yields of that year correspond with the dry matter yield achieved under extensive cultivation conditions (without nitrogen fertilizer) as described by SCHMIDKE ET AL. (1998). The dry matter yields of the third cultivation year (5,6 – 9,7 t/ha), however, are more than twice as high as those of the second cultivation year. They are also higher than the yields from the nitrogen intensive cultivation system described by VETTER ET AL. (1996) with 200 kg N/ha + 100 kg N/ha after the first cutting (per year; the fertilizer used was calcium ammonium nitrate). This large increase in yield in the third cultivation year is caused by an increase in the height (20 – 40 cm higher) and by the production of runners: the number of stalks per plot more than doubled in the third cultivation year. Additionally the undersowing of clover (Trifolium repens) seems to have had a positive effect on the growing of fibre nettle.
The fibre yields lie between 335 – 411 kg/ha in the second cultivation year and between 743 – 1.016 kg/ha in the third cultivation year. Clones with a high dry matter yield have a low fibre content and vice versa. Therefore the differences between the clones in dry matter yield/ha and fibre content are balanced and there is no more difference between the fibre yield/ha of the clones.
The fibre content after chemical processing lies in both the second and the third cultivation year between 8 – 16 % drymatter (stalks). This result confirms the maximum fibre contents reported in recent literature (DREYER ET AL. 1996, DREYER & DREYLING 1997, SCHMIDTKE ET AL. 1998, KÖHLER ET AL. 1999, FRANCKEN-WELZ ET AL. 1999). Clone 8 and Clone 9 have the highest fibre content in 1998 (16,0 respectively 14,5 %), and Clone 8 (15,7 %) in 1999.
There is no significant difference between the fibre quality (fibre strength, elongation, fibre fineness, lenght of fibre) of the five nettle clones. In general the fibre material is very inhomogeneous, which is caused by the differing consistence of the upper and the lower part of the stalk and by fibre processing methods. In principle, nettle fibres are suitable for textile use, however, the further developement of an economic and functional method for processing along with high yields is essential.
The results show that higher yields and fibre contents were achieved in the third cultivation year under the described cultivation conditions of organic farming than other authors (BREDEMANN 1959, VETTER ET AL. 1996, DREYER ET AL. 1996, SCHMIDTKE ET AL 1998, FRANCKEN-WELZ ET AL. 1999). The yields of the third cultivation year are higher than the minimum for economic cultivation as defined by DREYER & DREYLING (1997). The cultivation of fibre nettle under the conditions of organic farming in Austria is therefore possible, as long as fibre processing plants and consumer demand exists.
There is a need for further research in optimizing cultivation methods in organic farming (undersowing of leguminosae, manuring with slurry, row width, crop rotation) as well as in optimizing fibre processing methods for the quality of raw materials available and taking into account further processing into textiles (e.g. production of a pure yarn or a mixed yarn with cotton). There is also a need for research into possibilities to use fibres from different parts of the nettle plant for different purposes (e.g. textile and industrial uses)
Production and processing of organically grown fiber nettle (Urtica dioica L.) and its potential use in the natural textiles industry: A review
In Europe, the perennial stinging nettle was cultivated during the 19th century until the Second World War and has a long history as a fiber plant. Clone varieties dating back to the early 20th century are still maintained at European research institutions. The fiber content of clones ranges from 1.2 to 16% dry matter, and fiber yields range from 0.14 to 1.28 Mg/ha. Varietal purity of fiber nettle can only be achieved by planting cuttings. The harvesting of fiber starts in the second year of growth and the crop may produce well for several years. Several agronomic practices influence fiber quality, but causal relations are not yet well understood. Various parts of the fiber nettle plant can be used as food, fodder and as raw material for different purposes in cosmetics, medicine, industry and biodynamic agriculture. Organically produced fibers are in demand by the green textile industry and show potential that is economically
promising
On the Determination of the Polarized Sea Distributions of the Nucleon
The possibilities to determine the flavor structure of the polarized sea
(antiquark) distributions of the nucleon via vector boson production at high energy polarized hadron--hadron colliders, such as the
Relativistic Heavy--Ion Collider (RHIC), are studied in detail. In particular
the perturbative stability of the expected asymmetries in two representative
models for the (un)broken flavor structure are investigated by confronting
perturbative QCD leading order predictions of the expected asymmetries with
their next--to--leading order counterparts.Comment: 28 pages, LaTe
Estimating the demand for risk reduction from foodborne pathogens through food irradiation
In this study the response of US consumers to irradiation in meat processing is examined. Despite scientific evidence of the effectiveness and safety of irradiation, meat processors and retailers have been slow to market irradiated beef products due to uncertainty about consumer acceptance. The objective of this study was therefore to examine the factors influencing consumer demand for irradiation using data from a contingent valuation (CV) survey with 819 households in eight midwestern US states. The analysis focused on the value of reduced risk from Escherichia coli O157:H7 and Salmonella in ground beef consumption. Respondents were on average willing to pay a price premium of 22 cents/lb. for safer ground beef. Willingness to Pay (WTP) amounts were influenced by protective actions at home and varied partly with the scope of the risk reduction.food safety, irradiation, Willingness to Pay (WTP), Contingent Valuation (CV), Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Risk and Uncertainty,
Novel Method to Process Cystic Fibrosis Sputum for Determination of Oxidative State
Background: Induced sputum is the most commonly used method to analyze airway inflammation in cystic fibrosis (CF) patients ex vivo. Due to the complex matrix of the sample material, precise and reliable analysis of sputum constituents depends critically on preanalytical issues. Objectives: Here we compared the commonly used method for sputum processing by dithiothreitol (DTT) with a novel mechanical method in regard to basal cellular parameters, neutrophil markers and glutathione (GSH) levels. Methods: Sputum samples from CF patients were processed in parallel with or without the use of DTT. The key improvement of the mechanical method was the processing in many very small aliquots. Cellular and humoral markers were assessed and compared according to Bland-Altman. Results: Total cell count, cell viability, differential cell count, neutrophil elastase levels and flow cytometrically analyzed neutrophil markers (CD63, CD11b, DHR) did not differ between the two methods. Intracellular and extracellular GSH levels were significantly higher in DTT-treated samples (p = 0.002). Conclusion: The mechanical sputum-processing method presented had a similar yield of cells and fluids as the conventional DTT method and the advantage of omitting the introduction of reducing agents. This method allows a more reliable analysis of redox-dependent airway inflammation in sputum cells and fluid from CF patients than methods utilizing DTT. Copyright (C) 2009 S. Karger AG, Base
A Resource-Constrained Optimal Control Model for Crackdown on Illicit Drug Markets
In this paper we present a budget-constrained optimal control model aimed at finding the optimal enforcement profile for a street-level, illicit drug crackdown operation. The objective is defined as minimizing the number of dealers dealing at the end of the crackdown operation, using this as a surrogate measure of residual criminal activity. Analytical results show that optimal enforcement policy will invariably use the budget resources completely. Numerical analysis using realistic estimates of parameters shows that crackdowns normally lead to significant results within a matter of a week, and if they do not, it is likely that they will be offering very limited success even if pursued for a much longer duration. We also show that a ramp-up enforcement policy will be most effective in collapsing a drug market if the drug dealers are risk-seeking, and the policy of using maximum enforcement as early as possible is usually optimal in the case when the dealers are risk averse or risk neutral. The work then goes on to argue that the underlying model has some general characteristics that are both reasonable and intuitive, allowing possible applications in focussed, local enforcement operations on other similar illegal activities.crackdown enforcement;illicit drug markets;optimal control
Transport of proteins into the various subcompartments of mitochondria
The import of proteins into mitochondria is an intricate process comprised of multiple steps. The first step involves the sorting of cytosolically synthesized precursor proteins to the mitochondrial surface. There precursor proteins are recognized by specific receptors which deliver them to the general import site present in the outer membrane. The second stage of import involves a series of complex intraorganelle sorting events which results in the delivery of the proteins to one of the four possible submitochondrial destinations, namely the outer and inner membranes, the matrix and intermembrane space. Here in this review, we discuss the current knowledge on these intramitochondrial sorting events. We especially focus on targetting of proteins to the intermembrane space. Sorting to the intermembrane space represents a particularly interesting situation, as at least three separate targetting pathways to this subcompartment are known to exist
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