Analytical Algorithms for the Blend Ratios by Fibre-bundle Tensile Curves Part I: Typical Tensile Curve and the Strength and Work Methods

The blend ratio and tensile properties are vital important characteristics of blended fibre bundles. Fibre-bundle tensile behaviour has been measured by means of the Sirolan-Tensor in order to derive a typical specific stress — extension curve. According to the typical tensile curve, the relationships between the blend ratio and the tensile parameters are discussed and established. Two new algorithms, so-called the strength method and the work method, have been developed for the blend-ratio estimation of blended fibre bundles. The relevant blend-ratios and calculations of the two methods are defined in detail. Also, the characteristics have been explained for every calculation and compared to each others. The experimental results show that the blend ratios estimated from the theoretical methods are high coincidence with the measured results. Meanwhile, the specific stress — extension curve of blended fibre bundles depends directly on the blend ratios of the fibre bundles.

Analytical Algorithms for the Blend Ratios by Fibre-bundle Tensile Curves Part Ⅱ: Calculations of the Modulus Method and the Percentage Method

The principles for the modulus method and the percentage method are established and discussed in the part following Part Ⅰ of the series papers, in which we proposed the various algorithms of the strength method and the work method. The samples of Wool/PET blended fibre bundles, the method of fibre-bundle tensile tests and the typical specific stress-extension curves from the fibre bundles with different blend ratios are the same as in Part Ⅰ. It can be found that the theoretical results estimated by the modulus and percentage methods accord with the experimental values highly though the calculations of the two methods are slightly more complex than those of the strength and work methods. Especially, using the modulus method can not only avoid the influence of the error caused by the determination of the tensile curve of no fibre breaking in stretching, Y(e), but also need not to know the tensile curves of mono-component fibre bundles in certain calculation. The latter advantage of the modulus method exists in the percentage method too, but it should adopt the improved calculation of ones.

Analytical Algorithms for the Blend Ratios by Fibre-bundle Tensile Curves Part Ⅲ: The Definition Method and the Relationships between the Blend Ratio and Tensile Parameters Calculated from Different Ways

The algorithms of the strength, work, modulus and percentage methods have been introduced and discussed in Part Ⅰ and Part Ⅱ of the series papers. As the following, the percentage-function calculation and the frequency-function calculation of the definition method are defined and developed in detail. Meanwhile, the procedures to find the tensile parameters are analysed experimentally and involve “ED” being the average values of the corresponding tensile parameters of each bundle tensile curve measured; “EC” being the tensile parameters obtained from the averaged experimental tensile curve; and “TC” being the parameters of the theoretical tensile curve according to the corresponding nominal blend ratio. The theoretical and experimental results indicate that the blend ratio estimated by the definition method from wool/polyester blended fibre bundles has a high correlation with the actual blend ratio though the variables to be known in this method are the most of all the methods and there exist the difficulty to solve fibre bundle tensile behaviour without fibre broken in accuracy and that there are high correlations between the EC and TC data and the tensile parameters should be calculated using the EC method rather than the ED method with the exception of the bundle initial modulus. The relationships between blend ratios and the tensile properties of blended fibre bundles can be used to select the optimum blend ratio of blended tops or yarns.

Effects of pyrolyzed semi-char blend ratio on coal combustion and pollution emission in a 0.35 MW pulverized coal-fired furnace

The effects of blend ratio on combustion and pollution emission characteristics for co-combustion of Shenmu pyrolyzed semi-char (SC), i.e., residuals of the coal pyrolysis chemical processing, and Shenhua bituminous coal (SB) were investigated in a 0.35 MW pilot-scale pulverized coal-fired furnace. The gas temperature and concentrations of gaseous species (O2, CO, CO_(2), NO_(x) and HCN) were measured in the primary combustion zone at different blend ratios. It is found that the standoff distance of ignition changes monotonically from 132 to 384 mm with the increase in pyrolyzed semi-char blend ratio. The effects on the combustion characteristics may be neglected when the blend ratio is less than 30%. Above the 30% blend ratio, the increase in blend ratio postpones ignition in the primary stage and lowers the burnout rate. With the blend ratio increasing, NO_(x) emission at the furnace exit is smallest for the 30% blend ratio and highest for the 100% SC. The NO_(x) concentration was 425 mg/m^(3) at 6% O_(2) and char burnout was 76.23% for the 45% blend ratio. The above results indicate that the change of standoff distance and NO_(x) emission were not obvious when the blend ratio of semi-char is less than 45%, and carbon burnout changed a little at all blend ratios. The goal of this study is to achieve blending combustion with a large proportion of semi-char without great changes in combustion characteristics. So, an SC blend ratio of no more than 45% can be suitable for the burning of semi-char.

Blending Ratio Analysis of Akund / Cotton Blended Yarn Based on Micro Projection

A microscope method was developed for testing the blending ratio of akund/cotton blended yarns. Fiber characteristics such as diameter, longitudinal feature, and hollow structure were observed to identify akund and cotton. Therefore, the measurement of the blending ratio for akund/cotton blended yarns based on each fiber's amount, moisture regain, and metric count was available. The results show that using specimen's longitudinal section is more effective during the fiber counting than specimen's transverse section benefiting from the separation of the fibers.

The Hydration of Blended Cement at Low W/B Ratio

The hydration process,hydration product and hydration heat of blended cement paste mixed with mineral admixture and expansive agent at low W/B ratio are studied by XRD,thermo analysis,and calorimetry instrument,and they were compared with those of pure cement paste.The results show that pure cement and blended cement at low W/B ratio have the same types of hydration products,but their respective amounts of hydration products of various blended cements at same ages and the variation law of the amount of same hydration products with ages are different;The joint effect of tumefaction of gel-ettringite due to water absorption and the expansive pressure on the pore and rift caused by the crystalloid ettringite is the impetus of the volume expansion of cement paste,and the former effect is much greater than the latter one.

Effects of various donor:acceptor blend ratios on photophysical properties in non-fullerene organic bulk heterojunctions

The composition ratio of donor and acceptor materials in organic bulk heterojunction (BHJ) is one of the key parameters to govern the performance in organic solar cells (OSCs). Therefore, high-performance non-fullerene organic bulk heterojunction consisting of poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b' ]dithiophene))-co-(1,3-di(5-thiophene-2-yl)–5,7-bis(2-ethylhexyl) benzo[1,2-c:4,5-c']dithiophene-4,8-dione)] (PBDB-T) and 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))–5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2' ,3'-d' ]-s-indaceno[1,2-b:5,6-b' ]-dithio-phene (ITIC) are used to investigate the correlation among various donor: acceptor (D:A) ratios, photophysical properties and photovoltaic performance. Interestingly, the function of short-circuit current (Jsc) and D:A ratios demonstrates an axisymmetric trend. When the blending ratio of D:A deviates from the optimal ratio, the symmetrically decreased Jsc is derived from a reduction in the D:A interface or amorphous region. Research on the steady-state photoluminescence (PL), the time-resolved fluorescence spectroscopy measurements, atomic force microscopic (AFM) and grazing-incidence small angle X-rays scattering (GIWAXS) indicates no significant variation in energy loss in the process of changing D:A ratios in BHJs. With high donor or acceptor content, the domain size improves significantly, but the distance of π-π stacking corresponding to molecular packing has not changed significantly, and the bi-continuous percolation pathways were not obviously influenced.

Effect of Blending Ratio on the Properties of Ramie/Polyester Blended Yarn

The effects of the blending ratio on the properties of Ramie/Polyester blended yarns are discussed in this paper. The experimental results show that the elongation of the yarn with the polyester content more than 40% is better than that of others. There is a lowest tenacity of the yarn corresponding to the blending ratio of 50/50 or so. The other properties of the yarn, such as the evenness and hairiness, will be improved with the increasing of the polyester content.

ESTIMATION OF BLENDING RATIO OF TWO-COMPONENT FIBER BUNDLE FROM BUNDLE LOAD-ELONGATION CURVE

In this paper, two methods were developed to assess the blending ratio of two-componentfiber bundles. They were the peak-height method and the slope method. The relationship be-tween blending ratio and testing data was analysed, and the regression curves were obtained bystepwise regression method. It was pointed out that the testing errors of both methods were lessthan two percent. The validities of both methods were verified by experiments, All calculationsof both methods were completed by computer. The blending ratio was ascertained from the test-ing data of bundle fiber strength tester which was made by the authors themselves.

Blending Fineness Ratio of Fibers for Spinning Fine Denier Fibers

The paper deals with the theoretic relationship betweenfineness of man-made fibers blended with natural fibersand regularities of the yarns made from them.Throughestablishment of the theory model and digitally analysisusing Matlab software,the optimum fineness of the fi-bers could be figured out.

Investigation of the Effects of a Large Percentage of Dried Sludge on the Operation of a Coal-Fired Boiler

A 600 MW coal-fired boiler with a four-corner tangential combustion mode is considered here to study the combustion features and pollutant emissions at different loads for large-percentages of blending dried sludges.The influence of the over-fired air(OFA)coefficient is examined and the impact of the blending ratio on the boiler operation is explored.The results show that for low blending ratios,a slight increase in the blending ratio can improve the combustion of bituminite,whereas a further increase leads to the deterioration of the combustion of blended fuels and thus reduces the boiler efficiency.Enhancing the supporting capability of the secondary air effectively reduces the slagging degree in the bottom ash hopper and improves the burnout rate of coals.For a large-percentage blending case at full load,it is found that the OFA coefficient must be reduced appropriately,otherwise,a secondary high-temperature combustion zone can be generated in the vicinity of the furnace arches,causing high temperature slagging and superheater tube bursting.Considering the influences of combustion and pollutant emissions,the recommended OFA coefficient is 0.2.Blending dried sludge under low loads increases the flue gas temperature at the furnace exit.While reducing the flue gas temperature in the main combustion region,which is beneficial to the safe operation of the denitrification system.Increasing the blending ratio and reducing load lead to an increase in NOx concentration at the furnace exit Sludges with low nitrogen content are suggested for the practical operation of boilers.

天然气管道掺氢输送研究现状与分析

天然气管道掺氢输送是实现大规模、远距离和低成本氢气运输的手段之一,但氢气掺入天然气管道给管线运行工况、安全维护等带来了不容忽视的影响,具有一定的安全隐患。为此,围绕国内外天然气管道掺氢输送的技术研究与工程应用现状,讨论了影响天然气管道掺氢安全输送的主要因素,即掺氢引起的天然气物性改变、氢致失效和掺混不均,以及掺氢管道泄漏扩散和燃爆的安全问题。结果表明,天然气掺氢后,对现有管材提出了新要求,需开展相关实验以揭示氢致失效机理,掺氢天然气管道停输后是否发生气体分层与管道是否发生氢致失效密切相关。掺氢天然气管道泄漏扩散及自燃的安全范围、发生燃爆所需的最小掺氢比及燃爆机理尚不明晰,实验研究与实际运营存在差距。针对天然气管道掺氢输送的规范、标准及相关监管政策仍处于发展阶段,需要结合系统的研究数据及实践进一步完善。以上结果明晰了掺氢输送存在的风险,可为大规模掺氢混输的工程推广与实际运营提供参考。

New Contour Detection Model Working on Gray-Scale Image of Blended Yarn Cross-Section

The traditional Contour Tracing algorithm works on the binary image. It is developed that a new model called Facula Diffusion which can work directly on gray-scaled images according to the principle of human vision. The diffusion operation is controlled by four factors including approximation, closing, length-limiting, and hit-rate. Based on this model, three shape indices, i. e., dimension index, abnormity index, and fluctuation index, were put forward to describe the shape of objects. The rule of shape indices selection was discussed subsequently. Finally, the fibers in polyester/cotton blended yam are classified and the blending ratio is determined.

Investigation of the Physical Properties of Jute Blended Yarn Using a Novel Approach in Spinning Process

This work reports the successful outcomes to process the polyester, acrylic and wool fiber along with jute fiber exclusively using existing jute processing machineries for manufacturing the 241 tex jute blended yarn. The blending was performed at feeding stage of breaker carding machine and blending ratio of jute and polyester/acrylic/wool fibers is 80:20. Manufacturing of jute blended yarns will create a new opportunity for extending the uses of jute fibers in value added jute products. The present work is concerned with the investigation of physical properties such as tenacity, elongation % at break, quality ratio, unevenness, imperfections (thick, thin & neps) and hairiness of manufactured jute blended yarns. The jute-polyester (80/20) blended yarn shows the higher strength and more evenness compared to jute-acrylic (80/20), jute-wool (80/20) blended and 100% jute yarn.

The Strength of PLA Fiber/Tencel Blended Yarn

The PLA fiber is one of the green fibers.It is blended with Tencel fibers.The strength of the PLA fiber/Tencel blended yarn is tested.The relationship between the strength and the twist factor and the blended ratio is analyzed.The optimum blended ratio of the blended yarn is determined.

EFFECT OF PLASTICIZER ON THE MICROSTRUCTURE OF PS/PVC BLENDS

In this work, controlling of the particle size of PVC in PS/PVC blends was studied. It is shown that viscosity ratio and particle size can be changed by adding a third composition, such as plasticizers, and the distribution of the third composition in two phases plays a very important role in controlling viscosity ratio and particle size. When DOP was used as the plasticizer of PVC in PS/PVC blends, the particle size of PVC could not be reduced due to the transference of DOP into PS phase. When polycaprolactone (PCL) was used as the plasticizer of PVC in the same blends, the particle size of PVC could be descreased obviously because PCL does not migrate to PS phase.

控释掺混肥对小麦–玉米轮作体系产量、氮肥利用效率及氨挥发的影响

【目的】针对华北平原冬小麦-夏玉米轮作体系氮肥施用量大、氮肥利用率低、氮素损失严重等问题,探讨不同配比的控释掺混肥减氮和一次性施肥对周年作物产量、氨挥发损失和施肥经济效益的影响,确立麦玉轮作体系轻简高效和环境友好的施肥技术。【方法】于2022—2023年,在山东省德州市现代农业科技园区开展田间试验。冬小麦和夏玉米均设不施氮对照(CK)、农户习惯施氮(FFP)、优化施氮(OPT)、CRBF1(包膜尿素与普通尿素在冬小麦和夏玉米上的掺混比例分别为5∶5和3∶7)和CRBF2(包膜尿素与普通尿素在冬小麦和夏玉米上的掺混比例分别为7∶3和5∶5),共5个处理。基施和追施肥后,监测了氨挥发量、强度和损失率。分析了作物干物质积累和产量、氮素吸收量和氮肥利用效率,并计算了施肥经济效益。【结果】与FFP处理相比,CRBF1和CRBF2处理的夏玉米、冬小麦和周年产量差异不显著;CRBF1和CRBF2处理夏玉米氮肥偏生产力提高了8.87~9.86 kg/kg,CRBF2处理玉米氮肥回收率提高了48.4%(P<0.05);CRBF1和CRBF2处理冬小麦季氮肥回收率、氮肥农学利用率和氮肥偏生产力分别提高了30.3%~37.2%、5.22~5.77 kg/kg和6.52~7.06 kg/kg(P<0.05)。与FFP和OPT处理相比,CRBF1和CRBF2处理的肥料+施肥人工投入减少381~960元/hm^(2),周年净收入增加1208~2654元/hm^(2)。CRBF1和CRBF2处理的周年氨挥发损失量、损失强度和损失率较FFP处理分别降低了69.7%~71.9%、72.0%~74.5%和90.0%~94.1%(P<0.05)。【结论】包膜尿素与普通尿素在冬小麦、夏玉米季按照5∶5、3∶7,或者按照7∶3、5∶5的比例掺混一次性基施,均可在减少氮肥用量和施肥劳力投入的条件下,确保周年作物产量稳定,提高生产效益,并显著降低氨挥发损失,是华北平原冬小麦-夏玉米轮作系统高产高效、轻简施肥的有效氮肥施用技术。

胶粉/SEBS-g-MA共混比对复合材料粘弹行为的影响

研究了胶粉/SEBS-g-MA共混比对胶粉/SEBS-g-MA复合材料力学性能和粘弹行为的影响。结果表明:当共混比为60/40时,复合材料的力学性能最佳;随着胶粉用量的增加,应力松弛程度增大,随着热处理温度的升高,应力松弛可逆恢复程度先减小后增大;Mullins效应随着温度的升高逐渐减弱。

阻燃纤维/不锈钢纤维混纺纱线的力学性能分析

为探讨混纺比对纱线性能的影响,测试分析了5种不同混纺比的阻燃腈纶(A)/阻燃黏胶(R)/不锈钢纤维(G)(A90/G10、A70/R20/G10、A45/R45/G10、A20/R70/G10、R90/G10)混纺纱线的力学性能。结果表明:混纺纱线的拉伸断裂性能、弹性、蠕变性能、耐磨性能、扭转性能和弯曲性能随阻燃腈纶纤维混纺比的增加而提升;A45/R45/G10混纺纱线的疲劳性能较差,A90/G10混纺纱线的疲劳性能较好;在较大压力下,A70/R20/G10和R90/G10混纺纱线的压缩性能较好,在较小压力下,A20/R70/G10混纺纱线的压缩性能较好。

集输系统双管掺水工艺节能优化运行研究

某区块采用双管掺水集油工艺流程,由于现场无法判断掺水参数与现场工况的关系,导致回液温度远高于原油凝点,造成能源浪费,超出了经济运行成本区间。针对上述问题,利用Pipesim软件实现工艺建模,分析了掺水参数与工艺热能损失、井口回压、回液温度、工艺压能损失及能耗损失占比等参数的定量关系,得到了符合现场调控的一般性规律,并通过建立目标函数和约束条件,利用萤火虫算法实现了掺水比和掺水温度的自动调控。结果表明:掺水温度建议不超过75℃,掺水比不宜过高,现场调控应采用先调节掺水温度再调节掺水比的操作方式;随着掺水比和掺水温度的增加,单井运行费用存在最低值;经算法优化后,不同单井掺水比和掺水温度均有不同程度下降,预计每天可节约运行费用0.5万元~1万元。