Effect of chemical softening of coconut fibres on structure and properties of its blended yarn with jute     

Leena Mishra  Gautam Basu  Ashish Kumar Samanta 《Fibers and Polymers》2017,18(2):357-368

Coconut fibres were subjected to chemical treatment to obtain softer and finer fibres, suitable to blend with other finer fibre like jute. The chemical softening recipe was optimized using Box-Behnken design of experiments as 40 % Na₂S, 10 % NaOH and 6 % Na₂CO₃, which notably reduced the fineness (33 %) and flexural rigidity (74 %) and improved tensile property of coconut fibre. Effect of softening of coconut fibre on its process performance was studied in high speed mechanized spinning system at different blend ratios with jute. Blending with jute assists in spinning of coconut fibre to produce yarn of 520 tex at production rate of 5-6 kg/h, as compared to 15 kg/day for hand spun 5300 tex raw coconut fibre yarn in manual system. Analysis of blended yarn structure in terms of packing density, radial distribution of fiber components (SEM) and mass irregularity were investigated. SEM shows yarns made from softened coconut fibre -jute blends are more compact than raw coconut fibre -jute blend yarns. Coconut fibres were preferentially migrated to core of the yarn. Major yarn properties viz., tensile strength, and flexural rigidity of raw and chemically softened blended yarns were compared against their finest possible 100 % coconut fibre yarn properties. Yarn made up to 50:50 chemically softened coconut fibre-jute blend showed much better spinning performance, and having superior property in terms of reduced diameter, higher compactness, strength, initial modulus and less flexural rigidity than 100 % raw, 100 % chemically softened coconut fibre rope, and raw coconut fibre-jute blend yarns.  相似文献   

Fine root production and turnover in forest ecosystems in relation to stand and environmental characteristics   总被引：1，自引：0，他引：1  

Leena Finér  Mizue OhashiKyotaro Noguchi  Yasuhiro Hirano 《Forest Ecology and Management》2011,262(11):2008-2023

The production and turnover of fine roots (diameter ?2 mm) contributes significantly to carbon cycling in forest ecosystems. We compiled an up-to-date global database covering 186 stands from the literature and estimated fine root production (FRP) and fine root turnover (FRT) for boreal, temperate and tropical forests in order to study the relationships between FRP or FRT and environmental and stand variables. FRP for all plants (trees + understorey) was 311 ± 259 (n = 39), 428 ± 375 (n = 71) and 596 ± 478 g m⁻² a⁻¹ (n = 32) in the boreal, temperate and tropical forests, respectively, and the corresponding annual FRT rates were 0.77 ± 0.70, 1.21 ± 1.04 and 1.44 ± 0.76, respectively. When the FRP and FRT of trees were estimated separately for boreal and temperate forests the differences between the two biomes were insignificant. The mean FRP of trees for the two biomes combined was 306 ± 240 g m⁻² a⁻¹ (n = 86) and the annual FRT was 1.31 ± 1.43. Fine root biomass (FRB) was the most significant factor explaining the variation in FRP, and more so at the tree level than at the stand level, explaining 53% of the variation in FRP for trees at the tree level. The corresponding proportions at the stand level were 21% for all plants and 12% for trees. Latitude, mean annual temperature and annual precipitation each explained <20% of the variation in FRP or FRT. Fine root production and FRT estimates are highly dependent on the species included in the sampling, the sampling depth and the methods used for estimating FRP or calculating FRT. The results indicate that the variation in FRP on a global scale can be explained to a higher degree if we focus on tree roots separately from the roots of the understorey vegetation and on FRP at the tree level instead of FRP at the stand level or on FRT.  相似文献   

Enhanced separation and characterization of gluten polymers by asymmetrical flow field-flow fractionation coupled with multiple detectors     

Leena Pitkänen  Tuula Sontag-Strohm  Päivi Kanerva 《Journal of Cereal Science》2014

Asymmetrical flow field-flow fractionation (AsFlFFF) coupled with refractive index (RI) and multi-angle light scattering (MALS) detectors was used for macromolecular characterization of four different industrial wheat protein preparations (native, enzymatically hydrolyzed, physically separated, and denatured). The fractionation conditions were optimized separately for each protein sample and molar masses were determined from RI and MALS signals. Decaying cross-flow gradient seemed to produce best results for most of the gluten samples in terms of resolution and sample recovery. Sonication of the samples enabled the solubilization of the high-molar mass components with molar mass ranging from 8 × 10⁶ to 3.5 × 10⁸ g/mol. In case of lower-molar mass glutenins (α-gliadins, ω-gliadins, and high molecular weight glutenin subunits), AsFlFFF results were also compared with the results obtained with capillary gel electrophoresis.  相似文献   

Effect of clear-cutting and site preparation on the level and quality of groundwater in some headwater catchments in eastern Finland     

Hannu Mannerkoski  Leena Finr  Sirpa Piirainen  Michael Starr 《Forest Ecology and Management》2005,220(1-3):107-117

The impact of forest management (clear-cutting and site preparation) on stream hydrology has been studied in five small catchments in eastern Finland from 1991 and on groundwater levels and quality from 1994. The period 1992–1996 was a calibration period and in the autumn of 1996, 10% and 30% of the area of two of these catchments were clear-cut according to the forest management plan. Regeneration was carried out by disc-plowing in the autumn of 1998 and planting with Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) seedlings in the spring of 1999. The depth and quality of groundwater was monitored with four to nine groundwater wells installed in each catchment. There were 32 wells in all, 16 on upland mineral soils and 16 on peatlands (the perforated part of the pipe was totally put into the underlying mineral soil at eight sites). Sampling was made monthly during spring (March–May) and autumn (November–December) and bimonthly during summer (June–October). The samples were chemically analyzed for pH, electrical conductivity, and concentrations of total P and Fe (before filtration), and total N, NO₃⁻-N, NH₄⁺-N, total P, PO₄³⁻-P, SO₄²⁻-S, Ca²⁺, Mg²⁺, K⁺, Na⁺, Mn, Zn, Fe, Al³⁺, Cl⁻ (after filtration through 0.45 μm membrane filter). Data collected until the end of 2001 are reported. Groundwater was found in the down-slope wells in lower-lying areas, but not in those installed on the slopes with a thin (1–2 m) soil layer. Clear-cutting did not significantly affect groundwater levels in the wells. Nitrate N concentrations increased from 0.03 mg L⁻¹ level after clear-cutting and again after site preparation in the wells on upland soils and peatlands receiving water from the managed parts of the catchment. In one well at the lower edge of the managed area NO₃⁻-N concentrations reached 1–1.4 mg L⁻¹ in 2001 (fifth year after clear-cutting, third after disc-plowing), but mean concentrations remained <0.3 mg L⁻¹. Chloride concentrations also increased (50–100%) after treatments but the concentrations of other solutes showed no significant effect of treatment. It was concluded that changes in groundwater quality and quantity related to the clear-cutting were small and did not represent a danger to water quality or quantity.  相似文献   

Adaptation of the regional forestry administration to national forest, climate change and rural development policies in Finland     

Leena A. Leskinen 《Small-Scale Forestry》2006,5(2):231-247

This paper examines the process of adaptation of the regional forestry administration in Finland to cross-scale socio-ecological changes in national policies and in the forest ecosystem. Self-organisation and knowledge building are the key elements employed in this case study conducted in the Southern Ostrobothnia Forestry Centre to analyse how the knowledge claims and networks are created in order to implement wood energy development projects. The case study method and the theory of adaptive co-management are found to be useful in explaining and understanding policy implementation and outcomes at the regional and local levels. A wood energy project met the forest, climate change and rural development policy targets by facilitating the establishment of a small heating business producing renewable energy from young forest thinnings. The practical outputs at the local level were energy generation from a renewable source; an increase in the area of young forest management; and increased rural entrepreneurship and employment. The unintentional output was that a new wood market arose. As a result of the case study, a two-level network has been introduced as an adaptive policy implementation practice.  相似文献   

Variation in the amount and quality of litterfall in a Pinus sylvestris L. stand growing on a bog     

Leena Finr 《Forest Ecology and Management》1996,80(1-3):1-11

The amount and nutrient content of the above-ground litterfall was followed for 9 years in an unfertilized, PKMgB and NPKMgB fertilized Scots pine stand growing on a drained ombrotrophic bog in eastern Finland. The annual litterfall on unfertilized plots was 1995 kg ha⁻¹, of which needles accounted for 74%. The effective temperature sum (threshold value + 5°C) explained 99% of the annual variation in the amount of needle litterfall when the data from one atypical year were excluded from the analysis. Nutrient concentrations were, except for Fe, higher in needle litter than in the other litterfall fractions. Nitrogen, P and K concentrations were low in autumn, and those of Ca and Mn high, possibly owing to variation in the mobility of elements during senescence. The annual litterfall input of N to the soil was 12.4 kg ha⁻¹, and the corresponding values for P and K were 0.08 kg ha⁻¹ and 1.81 kg ha⁻¹, respectively. Fertilization reduced needle litterfall in the first year after treatment, but had no effect thereafter. The amount of other litterfall fractions was not affected by fertilization in any of the 9 years of the study. Nitrogen, P, K and B concentrations increased in the needle litter after both fertilization treatments. The results indicate long-term cycling of fertilizer nutrients on the site.  相似文献   

沙棘油对过敏性皮炎患者皮肤表层粗糙程度的影响     

杨宝茹  Kirsti O.Kalimo  Leena M.Mattila  Heikki P.Kallio 《国际沙棘研究与开发》2004,2(1):44-47

为验证沙棘籽油和沙棘果油对过敏性皮炎患者皮肤表层粗糙程度的影响，进行了有安慰剂对照的平行性研究。16位患者在4个月内每日分别服用5g沙棘籽油，沙棘果油或石蜡油。本研究包括皮肤表面粗糙程度的测量方法和测量参数的优化选择以及服油前、后手背和肩部非病变区皮肤表面的粗糙程度的测量。实验结果表明，服油前后皮肤表面的粗糙程度无明显统计学变化，说明沙棘油对过敏性皮炎患者非病变区皮肤的影响小于对病变区皮肤的影响。由于本研究中患者人数有限，此结论有待进一步验证。用表面光度测量仪可明显指示不同部位皮肤表层结构和粗糙程度的差异，在对皮肤的研究方面有广泛的应用前景。  相似文献   

Comparison of Conventional,Integrated and Organic Potato Production in Field Experiments in Finland     

Eero Varis  Leena Pietilä  Kauko Koikkalainen 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(1):41-48

Abstract

In 1987, a potato research project called “Minimized use of chemical inputs in potato production” was started in all five Scandinavian countries. In this paper, the results of one field trial series carried out at the Potato Research Institute, Lammi, Finland, during the years 1987–90 are reported. The main plots in a split-plot designed trial series consisted of three cropping systems: conventional, integrated and organic. The subplots included three cultivars differing especially in their late blight (Phythophtora infestans, (Mont.) de Bary) resistance: Bintje, Record and Matilda.

Canopy measurements showed differences that can be attributed to different nitrogen supply in decreasing order from conventional to integrated to organic system. The trial sites were very heavily infested with potato scab, resulting in a very low percentage of I-class yield in susceptible cultivars Bintje and Matilda. Late blight was a serious problem in organically grown Bintje, as expected.

Total yields in the integrated and organic systems were 10% and 36% lower, respectively, than in the conventional system. There was an interaction between cropping system and cultivar in favour of Bintje and the conventional system and Record in the organic system. The percentage of I-class yield was lowest in the conventional system. Some of the quality characteristics were slightly improved in the integrated and/or organic systems. Storage losses, caused mainly by tuber blight, were high in organically grown potatoes.

There were no large differences in production costs between the cropping systems. The main determinants of the unit production cost of potatoes were total yield and yield of I-class potatoes. The average unit costs were 1.76 FIM kg^?1 in the conventional, 1.68 FIM kg^?1 in the integrated and 2.36 FIM kg^?1 in the organic system. Record showed the lowest unit production costs in all systems ?1.33, 1.37 and 1.80 FIM kg^?1, respectively.  相似文献   

Ovipositional responses of the pulse beetle, Bruchus chinensis (Coleoptera: Bruchidae) to extracts and compounds of Capparis decidua     

Upadhyay RK  Rohatgi L  Chaubey MK  Jain SC 《Journal of agricultural and food chemistry》2006,54(26):9747-9751

Extracts of Capparis decidua stems and flowers showed insecticidal and oviposition inhibitory activities against Bruchus chinensis. The LC50 values of these extracts were found to increase with the increase in the polarity of the extract at different exposure periods. For instance, after 96 h, the LC50 values were found to be 3.619, 7.319, and 10.151 microg for CD1, CD2, and CD3, respectively. Extract CD7 was effective only at higher doses. The toxicity was found to be dose- and time-dependent. The females laid lesser number of eggs, when exposed to sublethal doses of different extracts and pure compounds, as compared to control. The maximum oviposition deterrence index was found for extract CD1 followed in decreasing order by CD2, CD3, and CD7. From extract CD1, two compounds were isolated and characterized as triacontanol (C1) and 2-carboxy-1,1-dimethylpyrrolidine (C2). When the females were exposed to sublethal doses of these compounds, they laid lesser number of eggs as compared to the control. C2 was found to have a slightly greater oviposition inhibition effect than C1. From fraction CD7, one novel compound labeled as CDF1 has been isolated and identified as 6-(1-hydroxy-non-3-enyl)tetrahydropyran-2-one. CDF1 has also shown insecticidal and oviposition inhibitory activities against B. chinensis at low concentrations.  相似文献   

Demodex gatoi -associated contagious pruritic dermatosis in cats - a report from six households in Finland     

Seppo AM Saari  Kirsi H Juuti  Joanna H Paloj?rvi  Kirsi M V?is?nen  Riitta-Liisa Rajaniemi  Leena E Saijonmaa-Koulumies 《Acta veterinaria Scandinavica》2009,51(1):40

Background

Demodex gatoi is unique among demodectic mites. It possesses a distinct stubby appearance, and, instead of residing in the hair follicles, it dwells in the keratin layer of the epidermis, causing a pruritic and contagious skin disease in cats. Little is known of the occurrence of D. gatoi in Europe or control of D. gatoi infestation.

Case presentation

We describe D. gatoi in 10 cats, including five Cornish Rex, two Burmese, one Exotic, one Persian and one Siamese, living in six multi-cat households in different locations in Finland containing 21 cats in total. Intense pruritus was the main clinical sign. Scaling, broken hairs, alopecia and self-inflicted excoriations were also observed.Diagnosis was based on finding typical short-bodied demodectic mites in skin scrapings, skin biopsies or on tape strips. Other pruritic skin diseases, such as allergies and dermatophytoses, were ruled out. In one household, despite finding several mites on one cat, all six cats of the household remained symptomless.Amitraz used weekly at a concentration of 125-250 ppm for 2-3 months, proved successful in three households, 2% lime sulphur weekly dips applied for six weeks in one household and peroral ivermectin (1 mg every other day for 10 weeks) in one household. Previous trials in four households with imidacloprid-moxidectin, selamectin or injected ivermectin given once or twice a month appeared ineffective.

Conclusion

D. gatoi-associated dermatitis is an emerging contagious skin disease in cats in Finland. Although pruritus is common, some cats may harbour the mites without clinical signs. In addition, due to translucency of the mites and fastidious feline grooming habits, the diagnosis may be challenging. An effective and convenient way to treat D. gatoi infestations has yet to emerge.  相似文献