INFLUENCE OF PLASMA TREATMENT ON SURFACE ENERGY OF UHMW-PE FIBRES

The fibre-resin adhesion has been reinforced by plasmatreatment on ultra-high molecular weight polythlene(UHMW-PE)fibres.This paper reports a study of the mechanism of the adhesion from thechanging of the surface energy.The experimental results show the surfaceenergy of the fibres has been greatly increased for plasma treatment andthus meets the prerequisite of fibre-resin adhesion.The fibres are comple-tely rinsed in the epoxy matrix.     

Effect of Nano-Al2O3 on the Properties of Ultra High MolecularWeight Polyethylene Engineering Material

The composite material of nano-Al 2O 3 and UHMW-PE was made by the way of pressing and agglomeration. Effect of nano-Al 2O 3 on the friction, wear characteristic of Ultra High Molecular Weight Polyethylene plastic was studied by using MPV-200 model friction and wear tester and caustic wear one. At the same time, the hardness of UHMW-PE was mensurated in sclerometer. The results showed that nano-Al 2O 3 not only decreases the friction coefficient of UHMW-PE, but also greatly reduce the wear of UHMW-PE.The hardness of UHMW-PE is improved. Which possesses important theoretic significance for optimizing of structure and property of UHMW-PE material.     

Selection Criteria for Short-fibre Flax

The industrial utilization of short fibres of Linum usitatissimum L. is advantageous for the environment and conserves natural resources due to savings in the production and waste management process. In 1990 a project was started to breed flax for short fibres in combination with oil production. In field experiments 22 (1990) and 20 (1991) varieties and progenies of earlier crosses, respectively, were tested. Phenotypic variation and linear correlations of parameters characterizing yield and its stability were examined with regard to their suitability as selection criteria. The results were as follows: A total harvest of 3 t/ha of short fibre and oil was produced, most of it fibre. The cross progenies tested in 1991 showed a high genetic potential for the combined use of fibre and oil, but their maturity needs to be synchronized better. Simultaneous selection of short-fibre flax genotypes for fibre content and seed yield on the one hand, or for oil content and fibre yield on the other, seems to be practicable. The plants should not exceed I m in height. Thousand-seed weight and oil content were not correlated in the progenies, thus making it possible to select for small-seeded genotypes.     

栽培株种纤维不同部位的电镜观察

应用扫描电镜对四个栽培棉种纤维的基部、中部、顶部位进行了观察研究，不同株种成熟纤维的形态差别以中部最为明显，表现出种间的遗传特征。在纤维表面观察到有似梭脊和沟槽的皱纹，它的分布和数量在二倍体棉种（亚洲棉和草棉）与四倍体棉种（海岛棉和陆地棉）间存在明显差异。棉纤维表面的皱纹能增加单纤维间的接触面和摩擦     

THE STUDY OF ANTI-SEISMIC BEHAVIOR OF THE TOP CORNER JOINTS OF REINFORCED CONCRETE FRAME WITH THE INCLUSION OF STEEL FIBRES

This paper first discusses the limited effect of steel fibre reinforcement on plain concrete and reinforced concrete. Then, making a comparison among the test results of three full-scale top corner joint assemblies of frame, in which only two of them are added with steel fibres in joint zone. The advantageous and disadvantageous influence in anti-seismic aspect is investigated after adding steel fibres in the joint zone. Finally, this paper gives an overall comment on the application future of using the steel fibres in every kinds of joint of anti-seismic reinforced concrete frame.     

Influence of Low Temperature Plasma Surface Treatment to UHMW-PE Composite on Its Impact Property

In this paper, the low-temperature plasma was applied to treat the surface of the fibers.The results show that the surface energy of the treated fibers increases greatly so that the fibers can be wetted very well by resin and the adhesion strength of the treated fibers to resin increases significantly.The mechanical characteristics of the PE composites are improved by the surface treatment of the fibers.In this paper, the mechanism of treatment has been discussed.The varieties of polar oxygen containing groups produced in the surface layer which form chemical bonding and the plasma etched pits spreading all over the surface of the treated fibers into which the resin penetrates to form the mechanical interlacing between fibers are the two reasons for the improvement.     

Friction and Wear Characteristics of Plastic Alloy Bearings under Different Lubricating Condition

Ultra High Molecular Weight Polyethylene (UHMW-PE) is a kind of high anti-wear engineering plastic with many excellent physical and mechanical performances. It has been widely applied in the field of mechanism such as bearing and pump. Effect of load, speed, time on friction and wear properties of Ultra High Molecular Weight Polyethylene(UHMW-PE)plastic alloy bearings under different Lubricating Condition are studied by using MPV-200 model friction and wear testing machine. The test results show that water lubrication reduces the friction coefficient of bearings but increases the wear rate as compared with dry friction. At the same time, wear mechanisms are analyzed systemically. It provides a theoretic basic for practical application of plastic alloy bearings     

Evaluation of Fibre Flax (Linum usitatissimum L.) Performance under Minimal and Zero Tillage in Eastern Canada

The feasibility of producing fibre flax in minimum tillage or zero tillage (ZT) systems was investigated. The results were variable between the sites, which differed in soil type and previous cropping history. Tillage regime had no impact on fibre flax phenological development including number of days to emergence, days to flowering and days to harvest at either site. However, tillage regime had a significant effect on mean stem diameter, dry matter content and plant height at all three sampling dates at the sandy loam site, and a significant effect on mid‐season plant height at the clay site. At the sandy loam site, ZT plots had the highest populations of plants with the finest stem diameters, the lowest branching ratios, but the shortest plants by the end of the season. Overall, plant densities were greater, stem diameters thinner, and biomass production higher in the heavier soil of the clay site. These results indicate that under the growing conditions present in 1998, fibre flax can successfully be grown in minimum or ZT systems on different soil types in Eastern Canada. Moreover, the growth of fibre flax in these systems does not compromise the proportion of tall plants having thin stems and minimal branching, a critical quality parameter for fibre flax production.     

A Prominent Role for Leaf Calcium as a Yield and Quality Determinant in Upland Cotton (Gossypium hirsutum L.) Varieties Grown Under Irrigated Mediterranean Conditions

Seven cotton (Gossypium hirsutum L.) accessions were tested over 2 years under irrigated Mediterranean conditions on a loamy soil with nitrogen (N) as the only nutrient input. The study aimed to identify the critical nutritional and physiological factors determining seedcotton yield and fibre quality. A suite of leaf physiological traits [chlorophyll content (assessed by SPAD), carbon isotope discrimination (Δ), ¹⁵N natural abundance (δ¹⁵N), leaf water potential, N and C concentrations, C/N ratio, K, Na, Ca and Mg concentrations, their sum and ratios] was assessed, and their interrelationships then analysed. It was found that physiological indices such as SPAD, Δ and δ¹⁵N failed to discern genotypes for yield and did not relate with fibre quality traits. At the same time, leaf Ca concentration was the trait that showed the strongest correlation with both seedcotton (SY) and lint yield (LY). An increase of K/Na ratio up to 5.74 was beneficial for SY but higher ratios impacted yield adversely. In this line, exclusion of K in favour of Ca (lower K/Ca ratios) increased both SY and LY. The above results could be explained by Ca²⁺ control over activity of tonoplast and plasma membrane cation channels, resulting in redistribution of K⁺ between cell compartments. It is suggested that Ca²⁺‐rich plants are more efficient in sequestering higher K⁺ quantities in leaf vacuoles, at the expense of cytosolic K⁺. Under K⁺‐limiting conditions, such redistribution may trigger programmed cell death and enhance leaf senescence. This would remobilize and translocate nutrients (e.g. N) and organic substances to sinks (seedcotton), contributing to higher yields reported in the present work.     

Histochemical and supramolecular studies in determining quality of hemp fibres for textile applications

Summary The composition and supramolecular structure of hemp primary bast fibres have been assessed using microscopy, compositional analysis, wide-angle X-ray diffractometry and CP-MAS ¹³C-NMR, in order to unambiguously define some quality parameters. The main components of the fibre wall were detected by histochemical reactions and modifications occurring during the plant growth have been pointed out. Some differences in fibre lignification degree were recorded among cultivars and confirmed by means of compositional and structural analysis. As for flax and kenaf, X-ray patterns revealed semicrystalline structure of hemp cellulose. NMR spectra and their probabilistic elaboration by MaxEnt method gave further insight on the presence of paracrystalline and amorphous phases and provided an accurate evaluation of polymeric components.     

European hemp industry: Cultivation, processing and product lines

Summary Two fibre plants are under cultivation in the European Union – flax on approximately 125,000 ha and hemp on approximately 15,500 ha in the year 2004. Seeds, hurds and especially fibres of hemp are used for further processing. The most important markets for hemp fibres produced in the EU are pulp and paper and the automotive industry. Just under 5% of the EU hemp fibres were used in the construction sector. Approximately 95% the whole production of 40,000 t of the hemp hurds are used as animal bedding and 95% of the estimated 6000 t per year hemp seeds are sold for animal feed, mainly as bird feed.     

THE DETERMINATION OF A CRACK IN STEEL FIBRE REINFORCED LIME-SAND CONCRETE

This paper studies the determination of a crack in steel fibre reinforced lime-sand concrete and its precision by acoustic emission(AE).The main AE paramters which influencethe precision of the determination of a crack are introduced,The properties of the lime-sand concretecan be increasted greatly with the steel fibre,The result in this paper can be used in the study of fi-bre re inforced cement concrete.     

Comparison of European Fibre Flax (Linum usitatissimum) Cultivars under Eastern Canadian Growing Conditions

Renewed interest in natural fibres, decreasing subsidies to European producers, and high production costs have led the move to reintroduce fibre flax (Linum usitatissimum L.) production into eastern Canada. Research was conducted at the Macdonald Campus of McGill University, Québec, Canada in 1998 and 1999 and at Winchester and Kemptville, Ontario, Canada in 1998, to assess the performance of seven European fibre flax cultivars. Parameters evaluated included plant density, branching ratio, stem diameter, fresh and dry biomass, and mean harvest height. Data from all sites and years were subjected to a pooled anova where appropriate. The cultivar main effect was detected for all parameters measured, with the exception of mean fresh weight and mean height at harvest. There was also a site main effect for all parameters except for branching ratio. A cultivar–site interaction was found for all parameters except for mean stem diameter and mean dry weight. Results indicate a strong potential for producing fibre flax in eastern Canada using currently available European cultivars.     

Changes in the microstructure and location of some bioactive compounds in persimmons treated by high hydrostatic pressure

Persimmon fruit are an important source of phenolic compounds, dietary fibre, and carotenoids. However, the location of these elements in the tissue is directly connected with processing techniques used. The aim of this work was to study the effect of high hydrostatic pressure (HHP) on the microstructure of persimmon fruit cv. ‘Rojo Brillante’ during different ripening stages and the relationship of this treatment with changes in the location of some bioactive compounds. Samples from persimmon fruit cv. ‘Rojo Brillante’ from two ripening stages, with and without deastringency treatment (95–98% CO₂), were treated by HHP at 200 and 400 MPa during 1, 3, and 6 min. A microstructural study using cryo-scanning electron microscopy, light microscopy, and confocal laser scanning microscopy (Cryo-SEM, LM, and CLSM) was carried out. Total soluble solid (TSS) content and some textural properties were also analyzed. The microstructural study showed that application of HHP caused cell wall disruption and intracellular component dispersion throughout the tissue, together with some nutritionally interesting compounds (tannins, fibres, and carotenoids). TSS content diminished in astringent samples when HHP was applied. This was attributed to precipitation of soluble tannins, which are responsible for fruit astringency. Therefore, it might be possible to omit a deastringency treatment with CO₂ before HHP treatments. HHP treatments caused an overall decrease in firmness for both ripening stages and an increase in cohesiveness (TPA analysis) in the more advanced stage.     

不同棉铃发育时期遮荫对棉纤维品质性状的影响

以中棉所41和鲁棉研18两品种为试材，设计3个遮荫时期（处理Ⅰ：棉铃发育0～20 d；处理Ⅱ：棉铃发育21～40 d；处理Ⅲ：棉铃发育41 d到吐絮），研究了遮荫对棉花纤维品质性状影响的规律。结果表明，遮荫使纤维长度变短，纤维伸长期增长，CK在25 d纤维达最大长度，处理Ⅰ、处理Ⅱ分别在35 d、30 d才达到最大长度，而处理Ⅲ对纤维伸长期没有影响；各时期遮荫都降低纤维断裂比强度和纤维成熟度，但使纤维细度增加，其中处理Ⅱ对纤维比强度、纤维成熟度和纤维细度的影响最大，与CK差异均达极显著水平；处理Ⅰ和处理Ⅲ影响较小。各时期遮荫对两品种纤维品质性状的影响趋势一致。     

Genetic variation, heritability and progeny testing in meadow bromegrass

Meadow bromegrass is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. Because relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate genetic parameters and assess breeding methodologies for meadow bromegrass. Forty half‐sib (polycross and open‐pollinated) and full‐sib (selfed) progenies were evaluated for dry matter and seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fibre and acid detergent fibre. Genetic variation for seed yield, harvest index, and plant height was significant in the open‐pollinated and selfed tests. Genetic variation estimates for dry matter yield were negative (polycross), not significant (open‐pollinated), or significant (selfed). Estimates of genetic variation for quality traits were not significant, except for acid detergent fibre (selfed). Correlations among characters indicated that it is possible to simultaneously improve seed and forage yield. Rankings of progenies by the half‐sib tests for forage and seed yield were not altered by the use of the synthetic parental value (SV_i), which includes information from selfed progeny. The polycross progeny test did not discriminate parents as well as the open‐pollinated and selfed tests; this may have been a result of non‐random pollination in the polycross. Correlation among the progeny tests, showed that open‐pollinated and selfed progeny tests agreed for all characters, except for harvest index, while correlation between polycross and selfed tests were significant for six characters but not dry matter yield, and acid and neutral detergent fibres. The most dissimilar tests were polycross and open‐pollinated, with significant correlations found only for fertility index, height, spread and neutral detergent fibre. It was concluded that there was significant variation and moderate heritability for most traits in the meadow bromegrass populations evaluated, and that the open‐pollinated progeny test is the method of choice for selecting parents for synthetics of this species.     

Breeding for high yield and fibre quality in coloured cotton

In the present study, three types of coloured fibre cottons, i.e. white, brown and green, were compared for their fibre quality and yield. The comparison of fibre quality suggested that coloured fibre cotton was inferior as compared with white fibre cotton. To understand the effect of cellulose, mineral elements [nitrogen (N), phosphorus (P) and potassium (K)] and pH of fibre cells on the quality of fibre, these components were studied at different fibre cell developed stages in all three fibre cotton types. The cellulose content is closely associated with the quality of fibre. The higher fibre quality of white fibre cotton might be the result of the high cellulose content in it compared with coloured fibre cotton. A rapid and slow decrease in pH in white and coloured cottons, respectively, might have some effects on fibre elongation. Among the mineral contents, potassium is positively correlated with the fibre quality traits. The pigment development patterns in brown and green fibre cottons are not similar. In green fibre cotton it takes more time to deepen in colour as compared with brown fibre cotton. Possible strategies for the improvement in quality of coloured fibre cotton are discussed. The results of heterosis studies in coloured fibre cotton suggest that heterosis could improve yield and quality of coloured fibre cotton. In the present study, the hybrids between ZJU12A x ZJU05R and ZJU18A x ZJU01R, having an acceptable lint colour types plus better fibre quality and high yield performance, may be exploited further for their heterotic advantages.     

Effects of Deficit Drip Irrigation Ratios on Cotton (Gossypium hirsutum L.) Yield and Fibre Quality

Increasing irrigation costs and declining water availability compel producers to adapt irrigation strategies for maximum crop yield and water use efficiency. A field trial was conducted to observe the effects of various drip irrigation ratios (IR-0, IR-25, IR-50, IR-75 and IR-100) on water use efficiency (WUE), the irrigation water use efficiency (IWUE), lint yield, yield components and fibre quality at two upland cotton varieties during 2004 and 2005. WUE was found to increase from 0.62 to 0.71 kg m⁻³ as the irrigation water applied was reduced from 100 % to 75 % of soil water depletion. Deficit irrigation of cotton with drip irrigation at 75 % treatment level (IR-75) did not decrease seed cotton yield and yield components during 2 years, with the exception of the number of bolls in 2005. Among fibre quality parameters, no significant differences in fibre length, fineness, uniformity index and elongation were detected between the 100 % and 75 % irrigation levels in 2005. The results revealed that irrigation of cotton with a drip irrigation method at 75 % level had significant benefits in terms of saved irrigation water without reducing yield, and high WUE indicated a definitive advantage of employing deficit irrigation under limited water supply conditions.     

Optimisation of breeding for agronomic traits in fibre hemp (Cannabis sativa L.) by study of parent-offspring relationships

Summary In the framework of a comprehensive Dutch research project the feasibility of hemp cultivation for paper pulp production is being investigated. This project also includes a hemp breeding programme which was initiated at CPRO-DLO in 1990. Hemp breeding is primarily aimed at improving bast fibre production since bast fibre is qualitatively superior to woody core fibre for paper pulp production. The progress of the ongoing breeding programme is hampered by the lack of knowledge on the inheritance of agronomic traits.The following traits were examined on 252 parental plants in 1991 and subsequently on their progenies in 1992: fibre content, plant height, date of flowering, stem diameter and cannabinoid contents. For each trait heritabilities were estimated and direct and indirect effects of artificial selection were studied.The heritability of bast fibre content was high and mass selection proved to be an efficient method causing no undesirable influence on other characters. Characters not directly related to bast fibre yield such as date of flowering, plant height and stem diameter were shown to have disadvantages as selection criteria for the improvement of bast fibre yield.The cannabinoids THC and CBD were studied, as the acceptance of hemp cultivation requires a low level. The content of THC, the psychoactive component can be successfully reduced by mass selection, but it is not certain that mass selection is the most efficient method.