A study and investigation on the influence of static and dynamic loading on the properties of handmade persian carpet (I)

The paper reports the physical and mechanical properties of hand-woven carpets, which have been put under static force. Two groups of wool fibres, from two parts of Iran, were prepared to spin pile yarns for the carpets. Each group of the fibres included both conventional and tanned wool. Then two yarn counts, N_m=4/2 and 6/2, were spun for two different knot densities. After weaving the carpets, they were put under static force and their thickness variations were measured and plotted against time, in logarithm scale. The resiliency of the carpets piles after eliminating the static force, were measured and plotted against time, in logarithm scale, too. The results were compared to each other and analysed with respect to parameters such as the type and quality of the wool fibres as well as knot density of the carpets.     

Molding process influence on pull-off performance of composite stiffened panels

Two types of molding process of composite stiffened panels which are co-curing and secondary-bonding are investigated, and pull-off experiment was designed to obtain the load-carrying capability and failure modes. The results show that the main failure mode of the secondary-bonded composite stiffened panels is adhesive debonding between the skin and stiffener. The failure mode of co-cured stiffened panels is complex, which includes skin-stiffener debonding, fiber damage, delamination and so on. The performances of the co-cured stiffened panels are better than that of secondary-bonded stiffened panels. The debonding initiation and propagation were simulated by using the nonlinear finite element method. Using user subroutine and cohesive interface, Hashin and B-K failure criterion were applied to simulate co-cured stiffened panels and secondary-bonded stiffened panels respectively, and the simulation results agreed well with experimental results.     

An investigation into the grazing efficiency of perennial ryegrass varieties

The objective of this study was to compare the grazing efficiency of 30 perennial ryegrass varieties, differing in ploidy and heading date. Plots were grazed by lactating dairy cows and managed under a rotational grazing system with 19 grazing events occurring over two years. Pre-grazing and post-grazing compressed sward heights were measured with a rising plate meter. A mixed model was used to predict the post-grazing sward height of each variety based on year, grazing event, block and pre-grazing sward height. Residual grazed height (RGH) was derived as the difference between the actual and predicted post-grazing sward height and was used as the measure of grazing efficiency. Negative RGH values indicated that the actual herbage removed was greater than that predicted and so indicated a superior grazing efficiency. Varieties differed in their level of grazing efficiency (p < .001), with RGH values ranging from −0.38 to +0.34 cm. Tetraploid varieties exhibited significantly greater grazing efficiency performance than diploids (p < .001), with average RGH values of −0.13 and +0.13 cm respectively. A significant difference in grazing efficiency was found among recommended perennial ryegrass varieties that are not being recorded by mechanically harvested simulated grazing protocols. A variety reappraisal that included grazing efficiency could identify varieties capable of improving on-farm livestock productivity from grass.     

An investigation into the use of ranked set sampling on grass and grass-clover swards

Four experiments were conducted to assess the performance of ranked set sampling relative to random sampling for the estimation of herbage mass and clover content in grazed swards. The expected theoretical efficiencies were not observed due to the method of selection of quadrats and the nature of the distribution of herbage mass. Nevertheless there should be worthwhile improvement in precision over random sampling, provided that the quadrats within a set are as well spaced as possible, allowing, if necessary, for visual comparison.     

An investigation into the effect of cultures of lactic acid bacteria on fermentation in silage

Twenty-one strains of lactic acid bacteria were subjected to a range of tests based on established criteria to ascertain their suitability for use as inoculants for silage. The tests included a monitor of their growth in the presence of representatives of the microflora of forage crops with which they might have to compete for substrate, and their ability to effect rapid acidification and achieve a low pH in conditions which simulate low and high ensiling potential. In addition, their ability to produce acid from sugars and their action against organic acids found in forage crops, together with their tolerance of acid, elevated temperatures and conditions of low moisture availability (e.g. in wilted material) and possible proteolytic and amylolytic activities were examined. None or these cultures satisfied all of these criteria. However, three strains ( Streptococcus durans str. 1024, Lactobacillus acidophilus , str. 2356 and Lactobacillus plantarum str. 6) had a greater potential than the others.     

Layer by layer assembly of nanosilver for high performance cotton fabrics

High performance cellulosic fabrics are of increasing attention as a wearable fabric with special functions. The current report deals with preparation of multifunctional cotton fabrics by using simple and facile layer by layer technique. Firstly, silver nitrate was reacted with carboxymethyl cellulose to prepare Ag nanoparticles-carboxymethyl cellulose composite. Multi-layers of the so-obtained composite were applied on the cotton fabrics using pad-dry-cure method. Ag nanoparticles were deposited with mean size of 18.2 nm onto cotton fabrics which served as a cross linker between carboxymethyl cellulose macromolecules and cotton macromolecular blocks. Application of composite multilayers brought new properties for the finished cloths such like coloration, ultraviolet resistance, electrical resistance and biocidal action. The ultraviolet transmission radiation was significantly reduced to 7-10 % after applying ten composite layers. Valuable antibacterial textiles which are required in different medical purposes could be successfully produced, as excellent antibacterial activities were achieved by using the reported method. The developed process can be easily adapted to the existing textile machinery, making it industrially viable to produce fabric’s versatility.     

Effect of feed space allowance and period of access to food on dairy cow performance

Two experiments were conducted to examine the ‘long‐term’ effect of feed space allowance and period of access to feed on dairy cow performance. In Experiment 1, three horizontal feed space allowances (20, 40 and 60 cm cow^?1) were examined over a 127‐d period (14 cows per treatment). In Experiment 2, 48 dairy cows were used in a continuous design (10‐week duration) 2 × 2 factorial design experiment comprising two horizontal feed space allowances (15 and 40 cm cow^?1), and two periods of access to feed (unrestricted and restricted). With the former, uneaten feed was removed at 08·00 h, while feeding took place at 09·00 h. With the latter, uneaten feed was removed at 06·00 h, while feeding was delayed until 12·00 h. Mean total dry‐matter (DM) intakes were 19·0, 18·7 and 19·3 kg cow^?1 d^?1 with the 20, 40 and 60 cm cow^?1 treatments in Experiment 1, and 18·1 and 18·2 kg cow^?1 d^?1 with the ‘restricted feeding time’ treatments, and 17·8 and 18·1 kg d^?1 with the ‘unrestricted feeding time’ treatments (15 and 40 cm respectively) in Experiment 2. None of milk yield, milk composition, or end‐of‐study live weight or condition score were significantly affected by treatment in either experiment (P > 0·05), while fat + protein yield was reduced with the 15‐cm treatment in Experiment 2 (P < 0·05). When access to feed was restricted by space or time constraints, cows modified their time budgets and increased their rates of intake.     

中国茶叶在日本市场发展"空间"的探讨

20世纪80年代初,中国茶叶开始“正规”进入日本市场,20多年的努力成效显著,至今已得日本市场“三分天下”。2000年,中国向日本出口各类茶叶44435吨(含台湾和香港,下同),占日本国内年茶叶消费总量的29.51%。其中绿茶16758吨,占其国内茶叶生产总量的18.66%,占其进口量的94.47%;乌     

A theoretical investigation on the generation of strength in staple yarns

In this article, an attempt has been made to explain the failure mechanism of spun yarns. The mechanism includes the aspects of generation and distribution of forces on a fibre under the tensile loading of a yarn, the free body diagram of forces, the conditions for gripping and slipping of a fibre, and the initiation, propagation, and ultimate yarn rupture in its weakest link. A simple mathematical model for the tenacity of spun yarns has been proposed. The model is based on the translation of fibre bundle tenacity into the yarn tenacity.     

An investigation into the cytotoxic effects of 13-acetoxysarcocrassolide from the soft coral Sarcophyton crassocaule on bladder cancer cells

Active compounds from natural products have been widely studied. The anti-tumor effects of 13-acetoxysarcocrassolide isolated from Formosan soft coral Sarcophyton crassocaule on bladder cancer cells were examined in this study. An MTT assay showed that 13-acetoxysarcocrassolide was cytotoxic to bladder female transitional cancer (BFTC) cells. We determined that the BFTC cells underwent cell death through apoptosis by flow cytometry. Due to the highly-migratory nature of the BFTC cells, the ability of 13-acetoxysarcocrassolide to stop their migration was assessed by a wound healing assay. To determine which proteins were affected in the BFTC cells upon treatment, a comparative proteomic analysis was performed. By LC-MS/MS analysis, we identified that 19 proteins were up-regulated and eight were down-regulated. Seven of the proteins were confirmed by western blotting analysis. This study reveals clues to the potential mechanism of the cytotoxic effects of 13-acetoxysarcocrassolide on BFTC cells. Moreover, it suggests that PPT1 and hnRNP F could be new biomarkers for bladder cancer. The results of this study are also helpful for the diagnosis, progression monitoring and therapeutic strategies of transitional cell tumors.     

云南红碎茶制造工艺初探

世界茶叶贸易中90％以上为红茶,其中又以红碎茶为主。我国为了出口创汇,于1957年开始试制红碎茶,1964年试行出口、红碎茶曾一度成为我国茶叶生产的增长点。但我国传统制法的红碎茶茶黄素含量在0.7％以下,很少达到1％,只相当于国际上的中、下档茶水平,竞争力不强。因此,自我国外贸体制改革以来,我国红茶出口逐年减少,到2000年,我国出口红茶29450t,出口均价1.22美元/kg,仅占世界红茶出口总量的2.6％,价格只有印度、斯里兰卡、肯尼亚的50％左右。     

自然生态与名茶品第成因关系的调研

为科学论证“高山好水出好茶”这一理念,针对本县名茶发展的新态势,如何合理配置资源,发挥优质资源优势,打造产品区域品牌,这是确保优质、立稳“名牌品牌”的关键。     

An experimental investigation into the mechanical behaviour of 3D woven fabrics for structural composites

3D woven composites provide efficient delamination suppression, enhanced damage tolerance, superior impact, ballistic and blast performance characteristics over 2D fabric laminates. At the same time, this type of composites, having practically straight in-plane fibers, show significantly better in-plane stiffness and strength properties than respective properties of conventional composites. But, how the in-plane elastic and strength characteristics of this type of fabrics compare with respective in-plane properties of equivalent 2D woven fabrics. This paper presents a comprehensive experimental study of the comparison of in-plane tensile, bending, crimp interchange properties of UD, 2D, 3D orthogonal, 3D angle-interlock and 3D warp interlock multi-layer structures woven from E-glass tow. The results depict that the 3D woven fabrics have considerably superior mechanical properties with much lesser crimp compared to 2D fabrics.     

681A不育胞质对杂种一代农艺性状的影响

利用681A×714和681B×714F1作材料,比较胞质对杂种一代农艺性状的影响。结果表明:681A不育胞质对杂种一代的株高、角果粒数和千粒重有显著影响。     

略谈茶叶抗癌作用的研究与应用

近年来国内外的大量研究表明,茶叶具有抗癌、抗衰老、抗氧化、降血压、降血脂、降血糖乃至抗艾滋病等多种奇特功效。这里重点介绍茶叶的抗癌作用。一、茶叶抗癌研究概况近些年,世界上用茶叶做实验材料进行抗癌研究的有中国、日本、美国、英国、法国、俄罗斯、加拿大、土耳其、韩国等。日美两国的研究结果表明,茶具有抑制肺癌、胃癌和膀胱癌的功效。据报道,日本成年男子的吸烟率高达59%,美国是30%,但肺癌的发生率和死亡率都是日本低于美国。原因何在?美国一家研究机构用鼠进行绿茶抑制致癌效果的研究,得出了喂绿茶的鼠比不喂绿茶的鼠,肺癌发…     

The influence of seed rate and pesticides on the establishment and growth of white clover slot-seeded into a permanent pasture

The establishment and growth of white clover (cv. Grasslands Huia) was investigated in two experiments with seeds sown in slots cut in old permanent pasture in early May 1982. In the first experiment, fully protected from pests and diseases, either 50 (low), 100 (medium) or 200 (high) seeds were sown evenly per metre length of slot; 100 seeds were also sown in a clumped pattern unevenly. In the second experiment, the effects of various combinations of molluscicide, insecticide and fungicide were investigated.
Nine weeks after sowing there were 27, 37, 34 and 62 seedlings m⁻¹ on the low, medium even, medium uneven and high seed-rate treatments, representing percentage establishments of 54, 37, 34 and 31 respectively. By September, however, there were no significant differences between the dry weights m^−l of any of the treatments. In the second experiment, damage by slugs occurred early in treatments without molluscicide and caused a mean reduction of 70% in seedling establishment. As a result significantly smaller dry weights m⁻¹ of clover were recorded in September in these than in other treatments. Failure to protect against insects resulted in smaller seedlings.
The results indicated that variations in seed rate within the range investigated were not critical but that failure to protect against pests decreased percentage establishment and subsequent growth.     

An investigation into the factors influencing sugar levels in UK grown potatoes (cv. Record)

Summary Reducing sugar and sucrose content of potato tubers (cv. Record) grown in Tayside (northern United Kingdom (UK)) and Lincolnshire (southern UK) were monitored during the 1984 growing season and after two months storage at 10°C. Neither latitude nor agronomic factors were shown to affect sugar content. Significant correlations were found between the post storage reducing sugar content and the sugar contents measured at harvest. Regression analyses indicated that in immature tubers sucrose breakdown was responsible for reducing sugar accumulation during storage.     

生态园林城市的建设探讨

简述生态园林城市的内涵、特点及其功能,分析国内昆明、福州等城市在生态园林城市建设中出现的问题,针对这些问题初步提出建设生态园林城市的思路。     

中国有机茶商调查

近年来,中国有机茶发展呈现良好势头,本文通过对中国有机茶生产贸易商的调查,在取得一定数据资料的基础上,对中国有机茶生产贸易商的生产、加工、销售、出口等行为及存在的问题进行了原因分析,最后对有机茶发展趋势进行了展望。