Bundle Strength Research Articles

PAN monofilament in nanoscale: a novel approach

AbstractA novel electrospinning setup was employed for producing aligned polyacrylonitrile (PAN) monofilament in nanoscale. Unlike conventional method, the PAN monofilaments is collected using a rotating drum with various linear speed from bulk of nanofibers. it originates from two syringe infusion pumps contain 14wt% PAN/DMF solution which passes through two separate high voltage electric field. Various collecting drum speed were examined to clarify its effect on degree of alignment, internal structure and mechanical properties. Image process technique used to illustrate the best degree of alignment for nano-monofilament collected at take up velocity of 59.5 m/min. The amount of Crystallization Index (C.I) and orientation parameter calculated respectively from FTIR spectra and Raman spectra also supports the results demonstrated by image processing techniques. The ultimate strength and elastic modulus of nano-monofilament bundles increase with increase of take up velocity. They approach respectively to a maximum of 73.7 MPa and 4.2 GPa at take up velocity of 59.5 m/min. Results acquired by differential scanning calorimetry (DSC) show no significant effect on glass transition temperature with increasing take up velocity. However, minimum value of evolved heat caused by chemical reaction was obtained at surface speed of 59.5 m/min.

The mechanical properties of bamboo and vascular bundles

Abstract

Bundle and chirality influences on properties of carbon nanotubes studied with van der Waals density functional theory

AbstractWe study the binding strength and intertube distance of carbon nanotube bundles in dependence of their structure (chirality) with van der Waals density functional theory. We try to understand the bundling and debundling process of nanotube bundles and test whether an influence of chirality exists. The distance between the nanotubes in the bundles vary only in a small range within 3.3 and 3.4 Å, without any chiral angle and diameter dependence. We find an increase of van der Waals energy per length with increasing diameter of the nanotubes ${\left( {E_{{\rm vdW}}^{{\rm length}} {\propto} d\,{\rm or}\,\sqrt {d} } \right)}$ for tubes with diameters between 5.6 and 27.3 Å, but no obvious correlation between the chirality of the tubes and the van der Waals energy per length. The van der Waals energy per atom is decreasing with increasing tube diameter ${\left( {E_{{\rm vdW}}^{{\rm atom}} {\propto} 1/d\,{\rm or}\,1/\sqrt {d} } \right)}$.

Strength Test of Parallel Carbon Fiber Bundle for Prestressed Bridge

Because of good mechanical properties of the fiber composites, the fiber bundles without the resin curing process and with the features of high modulus, high strength and good performance of creasing resistance etc, can be used in prestressed structures. According to the strength properties of the fiber, the tensile characteristic function of the fiber bundles is derived. The tensile test is designed and the parameters of the weibull distribution are estimated based on the result of the test. The ultimate strength of fiber is inversely proportional to the length of fiber. The calculating strength should be reduced in design, because the discreteness of the strength of the fiber bundle in test is much larger than the calculated values.

Registration of TAM 04WB‐33s Upland Cotton with Improved Fiber and Yarn Properties

TAM 04WB‐33s upland cotton (Gossypium hirsutum L.) germplasm line (Reg. No. GP‐940, PI 662041) was developed by the Cotton Improvement Laboratory, Department of Soil and Crop Sciences, Texas A&M AgriLife Research and released in 2010 as part of an ongoing effort to create germplasm with combinations of improved fiber‐quality parameters, especially upper half mean length (UHML) and fiber bundle strength (FBS), that contribute to the production of improved yarn. TAM 04WB‐33s exhibited high volume instrument (HVI) UHML and FBS greater than the comparison cultivars when grown under irrigated culture at multiple locations in central and south Texas during 2007, 2008, and 2009. Limited yarn evaluation indicated that TAM 04WB‐33s produced 30‐count carded yarn that was 27% stronger and required 43% more force to break than either ‘DP 491’ or ‘FiberMax 832’. This germplasm line is competitive in all other fiber properties and in yield potential with current upland cotton cultivars adapted to central and south Texas.

Registration of ‘Tamcot 73’ Upland Cotton Cultivar

Tamcot 73’ upland cotton (Gossypium hirsutum L.) cultivar (Reg. No. CV‐128, PI 662044) was developed by the Cotton Improvement Laboratory, Department of Soil and Crop Sciences, Texas A&M AgriLife Research. Tamcot 73 was derived from a complex of crosses that date across several decades of the upland cotton improvement program at Texas AgriLife Research. The breeding lines 93WB‐57s and 95WE‐48, which are closely related to TAM 0155 and TAM 2055, respectively, were crossed in 1999. The F1 and F2 generations were advanced at College Station, TX in 2000 and 2001, with an F3 plant selected in 2002. The F3:4 progeny row was bulked with subsequent generations treated as a pure line for seed increase and performance testing. Tamcot 73 is a conventional cultivar that is competitive in yield potential with the current upland cultivars available for production in central and south Texas. Tamcot 73 exhibited a high–volume‐instrument upper half mean length equal to or greater than the comparison cultivars in four of five comparisons when grown under irrigated and nonirrigated culture in central and south Texas during 2005 through 2009. Uniformity of fiber length and fiber bundle strength of Tamcot 73 exceeded that of most of the commercial comparison cultivars in all environments, and micronaire was within accepted limits in all comparisons. The lint percentage of Tamcot 73 is acceptable yet below that of most current upland cultivars. Tamcot 73 provides producers with a competitive, high‐quality, conventional cultivar.

Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cottonization. There was a monotonically decreasing relationship between the strength and the number of processing steps, which was well fitted by an exponential regression line. The reduction factor was determined to be 0.27, indicating that the fiber bundle strength was on average reduced by 27% per processing step at the applied conditions. No large changes in cellulose content and crystallinity were observed, so the reduction in strength must be explained by other changes in the fiber ultrastructure. Altogether, the study presents a quantitative basis for reduction in strength of cellulosic fibers due to processing.

Morphological Diversity and per se Performance in Upland Cotton (Gossypium hirsutum L.)

A field experiment was conducted to find out the morphological diversity and per se performance of yield component traits, yield and a fibre quality traits eleven genotypes (four G. hirsutum cultivars viz., MCU 5, MCU 12, SURABHI and SVPR 2 and seven G. hirsutum genetic accessions viz., F 776, F 1861, SOCC 11, SOCC 17, TCH 1641, TCH 1644 and TCH 1646) during kharif 2005-06. Morphological traits of each genotype were measured on five randomly chosen plants in each replication. Significant differences were recorded for all the fourteen traits observed. The cultivar MCU 12 produced maximum yield (95.33 gm/plant) due to more number of sympodia (24.17/ plant), number of bolls (25.17/plant), boll weight (4.20 g), ginning outturn (35.43 %), lint index (6.12 g) and seed index (10.44 g). Among the eleven genetic accessions, most of them expressed lowest value in yield and quality traits except SOCC17 superior in micronaire (4.60?g/inch-1), SOCC11superior in fibre elongation (9.60 %) and TCH 1641 had high number of sympodia (28.97/plant) and number of seeds per boll (32). The cultivar SURABHI possess significantly more number of bolls (26.47/ plant), high ginning outturn (36.24 %), 2.5% span length (32.90 mm) and bundle strength(22.9 g/tex-1). The morphological traits data were used for assessing genetic diversity in the 11 cotton genotypes. NTSYS software was used to determine the genetic similarities and construct a dendrogram. The matrix of average taxonomic distance was estimated using Euclidian distance. The average taxonomic distance ranged from 0.1 to 1.4. At a Euclidean distance of 0.8, the 11 genotypes were grouped into IV clusters at 0.43% similarity level. Among the different clusters, the cluster size varied from one to four genotypes. The maximum number of genotypes was included in cluster I (four genotypes) and the minimum number in cluster II having only one genotype. The cluster III & IV each had three genotypes. The analysis of variance revealed significant divergences among all the genotypes for all characters. In future, greater morphological diversity shown among the genotypes can be used to generate potential and promising hybrids.

Fiber density between rhinal cortex and activated ventrolateral prefrontal regions predicts episodic memory performance in humans

The prefrontal cortex (PFC) is assumed to contribute to goal-directed episodic encoding by exerting cognitive control on medial temporal lobe (MTL) memory processes. However, it is thus far unclear to what extent the contribution of PFC-MTL interactions to memory manifests at a structural anatomical level. We combined functional magnetic resonance imaging and fiber tracking based on diffusion tensor imaging in 28 young, healthy adults to quantify the density of white matter tracts between PFC regions that were activated during the encoding period of a verbal free-recall task and MTL subregions. Across the cohort, the strength of fiber bundles linking activated ventrolateral PFC regions and the rhinal cortex (comprising the peri- and entorhinal cortices) of the MTL correlated positively with free-recall performance. These direct white matter connections provide a basis through which activated regions in the PFC can interact with the MTL and contribute to interindividual differences in human episodic memory.

Study of strength and its reliability of SiC fiber bundle by experimental and Monte-Carlo simulation approach

Tensile tests and Monte-Carlo simulation on the strength and its reliability of the SiC CVD (formed by chemical vapor deposition) fiber bundle were performed. The experimental and simulation results were compared and analyzed by fiber bundle strength theories. The experimental results showed that the strength of the SiC CVD fiber bundle was decreased as the number of fibers in the bundle was increased; while in the process, Weibull shape parameter of the bundle strength was increased. The experimental results were in good agreement with the Monte-Carlo simulation. In addition, Monte-Carlo simulation was used to clarify the detailed relationship between the strength of the SiC CVD bundle and the number of fibers in the bundle and the simulation results were compared with that of Coleman theory. The comparison revealed that the strength of the SiC CVD bundle converged to the value of Coleman theory as the number of fibers in the bundle increased; at the same time, the rate of convergence was increased as Weibull shape parameter was increased. Furthermore, the relationship between the strength of the SiC CVD fiber bundle and Weibull shape parameter of the SiC CVD fiber strength was also examined. It was found that the strength of the SiC CVD fiber bundle increased as Weibull shape parameter was increased although the number of fibers in the bundle was countable. Finally, the breaking-down process and the number of broken-fibers in the bundle depended on the number of fibers the bundle and Weibull shape parameter of the SiC CVD fiber strength.

Effects of Bond Primers on Bending Strength and Bonding of Glass Fibers in Fiber-Embedded Maxillofacial Silicone Prostheses

To evaluate the effect of three commonly used bond primers on the bending strength of glass fibers and their bond strength to maxillofacial silicone elastomer after 360 hours of accelerated daylight aging. Eighty specimens were fabricated by embedding resin-impregnated fiber bundles (1.5-mm diameter, 20-mm long) into maxillofacial silicone elastomer M511 (Cosmesil). Twenty fiber bundles served as control and did not receive surface treatment with primers, whereas the remaining 60 fibers were treated with three primers (n = 20): G611 (Principality Medical), A-304 (Factor II), and A-330-Gold (Factor II). Forty specimens were dry stored at room temperature (23 ± 1°C) for 24 hours, and the remaining specimens were aged using an environmental chamber under accelerated exposure to artificial daylight for 360 hours. The aging cycle included continuous exposure to quartz-filtered visible daylight (irradiance 760 W/m(2) ) under an alternating weathering cycle (wet for 18 minutes, dry for 102 minutes). Pull-out tests were performed to evaluate bond strength between fiber bundles and silicone using a universal testing machine at 1 mm/min crosshead speed. A 3-point bending test was performed to evaluate the bending strength of the fiber bundles. One-way Analysis of Variance (ANOVA), Bonferroni post hoc test, and an independent t-test were carried out to detect statistical significances (p < 0.05). Mean (SD) values of maximum pull-out forces (N) before aging for groups: no primer, G611, A-304, A-330-G were: 13.63 (7.45), 20.44 (2.99), 22.06 (6.69), and 57.91 (10.15), respectively. All primers increased bond strength in comparison to control specimens (p < 0.05). Primer A-330-G showed the greatest increase among all primers (p < 0.05); however, bonding degraded after aging (p < 0.05), and pull-out forces were 13.58 (2.61), 6.17 (2.89), 6.95 (2.61), and 11.72 (3.03). Maximum bending strengths of fiber bundles at baseline increased after treatment with primers and light aging in comparison with control specimens (p < 0.05), and were in the range of 917.72 to 1095.25 and 1124.06 to 1596.68 MPa at both baseline and after 360 hours aging (p < 0.05). The use of A-330-G primer in conjunction with silicone Cosmesil M511 produced the greatest bond strength for silicone-glass fiber surfaces at baseline; however, bond strength was significantly degraded after accelerated daylight aging. Treatment with primer and accelerated daylight aging increased bending strength of glass fibers.

Enhancing Productivity of Summer Irrigated Cotton Through Plant Growth Regulator and Foliar Nutrition 248

A field experiment was conducted at Agricultural College and Research Institute, Madurai to study the influence of plant growth regulator (NAA 40 ppm) and foliar nutrition (DAP 2%, KCl 1%) on summer irrigated cotton for enhancing the productivity along with recommended dose of fertilizers 60:30:30 Kg N,P 2 O 5 ,K 2 O ha -1 . The growth characters of cotton such as plant height, leaf area index and plant dry matter production at various stages crop growth (60,90 and 120 DAS) were greatly influenced by application of RDF NPK with NAA 40 ppm and DAP 2% foliar spray either at peak flowering and boll development stages or at squaring peak flowering stages. Yield attributes of cotton viz., number of symbodial branches plant-1 , fruiting points plant -1 , bolls plant -1 and boll weight were increased in the alone promising treatments as compared to control and other treatments. As a result, higher seed cotton yield (19.29 q ha-1 ) was obtained in cotton receiving RDF and sprayed with NAA 40 ppm and DAP 2% either at square formation and peak flowering or peak flowering and boll development stage. Quality characters of cotton like seed index, lint index, ginning percentage, Bartlett's index, bundle strength and fibre finess were not influenced.

Experimental Investigation on Mechanical Behavior of Moso Bamboo Vascular Bundles

Bamboo is a typical natural fiber reinforced composite material with superior mechanical strength and toughness. As a typical hierarchical material, the macroscopic properties of bamboo are determined by its microscopic structure. The vascular bundles are the reinforce phase in bamboo composite. There was little research on the variation of mechanical properties of bamboo vascular bundles. In this work, the mechanical properties of Moso vascular bundles along the axial direction were investigated by tensile test. It is shown that the longitudinal Young’s modulus and strength of the Moso vascular bundles are linearly increased from inner zone to outer surface.

TAM 04 O‐16L Long‐Staple Upland Cotton with Improved Strength

TAM 04 O‐16L (Reg. No. GP‐926, PI 659441) upland cotton (Gossypium hirsutum L.) germplasm line was developed by the Cotton Improvement Laboratory, Department of Soil and Crop Sciences, Texas AgriLife Research, Texas A&amp;M University, and released in 2009 as part of an ongoing effort to create germplasm with combinations of improved fiber quality parameters, especially upper half mean length (UHML) and fiber bundle strength (FBS). TAM 04 O‐16L exhibited high volume instrument UHML greater than 32.0 mm in five of six location‐years, which is the minimum UHML to be classified as extra‐long upland cotton according to Cotton Incorporated (Cotton Incorporated, 2009), and in one test TAM 04 O‐16L exceeded the minimum UHML of 34.8 mm for pima (G. barbadense L.). Fiber bundle strength exceeded that of ‘Deltapine 491’ and ‘FiberMax 832’, both of which exhibit excellent FBS among current non‐Acala upland cultivars.

TAM B139–17 ELS Upland Cotton

Extra‐long staple upland cotton (Gossypium hirsutum L.) germplasm lines have been developed by the Cotton Improvement Laboratory, Department of Soil and Crop Sciences, Texas AgriLife Research, Texas A&amp;M University, as part of an ongoing effort to create germplasm and/or cultivars with combinations of improved fiber quality parameters, especially upper half mean length (UHML) and fiber bundle strength. TAM B139–17 ELS (Reg. No. GP‐927, PI 659699) resulted from the cross of TAM 94L‐25 (PI 631440) and PD 6992 (PI 606812). This germplasm line exhibits high volume instrument UHML greater than the minimum for pima (G. barbadense L) combined with fiber bundle strength greater than ‘Fibermax 832’ and other non‐Acala upland cultivars.

Environmental Impact on the Combining Ability of Fiber Traits and Seed-Cotton Yield in Cotton

Hybrids are widely accepted in all crops to improve yield, but genotype × environment interaction plays an important role in achieving high yield and superior quality traits. Three cytoplasmic genetic male sterile lines and seven testers of Gossypium hirsutum L. varying in seed cotton yield and fiber traits were assessed for hybrid vigor using a line × tester system across three different locations. The objectives of this study were to estimate 1) level of heterosis and specific combining ability (SCA) for fiber traits and seed‐cotton yield; 2) correlation between general combining ability (GCA) and line per se, as well as correlation between genetic distance and SCA; and 3) influence of environmental factors on combining ability estimates and trait correlations in parents and hybrids. The level of heterosis was acceptable for seed-cotton yield (32.46%) and fiber traits except uniformity ratio and fiber elongation. Combining-ability analysis across environments showed significant (P < 0.01) effects for genotypes, GCA, SCA, genotype × environment, GCA × environment, and SCA × environment interactions. Combining-ability variance revealed predominance of non-additive gene effects for seed-cotton yield, gin turnout, and micronaire, and additive gene effects for bundle strength and fiber elongation. A positive relationship was found between GCA effects and mean performance of parents, midparent value, and hybrid performance, with emphasis on the dominant gene effect for most of the traits studied. Positive correlation was found between GD and SCA effect. Environmental factors significantly affected the expression of fiber traits and seed‐cotton yield. The correlations among fiber traits and seed-cotton yield emphasized the possibility for improving both yield and fiber properties.

Impact of three hours of discotheque music on pure-tone thresholds and distortion product otoacoustic emissions

The aim of this study was to investigate whether distortion product otoacoustic emissions (DPOAEs) are a suitable means for detecting changes in outer hair cell (OHC) functionality due to exposure to three hours of discotheque music and whether efferent reflex strength of the medial olivocochlear bundle is able to predict the ear's susceptibility to high-level noise. High-resolution DPOAEs (Δf(2)=47 Hz) were recorded between 3.5 and 4.5 kHz at close-to-threshold primary tone levels. For comparison, high-resolution pure-tone audiometry was conducted in the same frequency range. Efferent reflex strength was measured by means of DPOAEs at a specific frequency with and without contralateral acoustic stimulation. A significant deterioration of more than 10 dB was found for pure-tone thresholds and DPOAE levels indicating that three hours of high-level noise exert a considerable influence on hearing capability and OHC functionality. A significant correlation between shifts in pure-tone threshold and shifts in DPOAE level occurred when removing data with differing calibration across measurements. There was no clear correlation between efferent reflex strength and shifts in pure-tone threshold or shifts in DPOAE level suggesting that the applied measures of efferent reflex strength may not be suitable for quantifying individual vulnerability to noise.

Registration of Four Exotic Germplasm Lines Derived from an Introgressed Population of Cotton

John Cotton (JC) cotton germplasm was developed from multiple crosses between Gossypium hirsutum L. and G. barbadense L. JC14 (Reg. No. GP‐921, PI 658308), JC32 (Reg. No. GP‐922, PI 658309), JC60 (Reg. No. GP‐923, PI 658310), and JC65 (Reg. No. GP‐924, PI 658311) were released by the USDA‐ARS in 2009 for their exceptional fiber quality or desirable combinations of lint yield and fiber properties. These lines were tested for agronomic performance and fiber quality in 2006, 2007, and 2008 at three locations. JC14 and JC60 averaged 277 and 281 kN m kg−1, respectively, for bundle strength over 3 yr compared with 258 kN m kg−1 for the high quality check ‘Phytogen 72’ (PHY72). The properties of 50% span length, short fiber content, and fineness in these two lines were also superior to those of PHY72. Lint yield of JC65 averaged 1190 kg ha−1, compared with 1565 and 1090 kg ha−1 for ‘Deltapine 555BG/RR’ and PHY72, respectively. Elongation (8.06%), short fiber content (3.46%), and fineness (174 mg km−1) in JC65 were all superior to those of PHY72. Lint yield of JC32 averaged 1161 kg ha−1 with 8.21% elongation, 3.52% short fiber content, and 174 mg km−1 fineness. The superior traits in these lines can be incorporated into Upland cotton cultivars for genetic improvement of both lint yield and fiber quality.

Simulation of Small Filament Bundles Breaking Process

The strength of fibers and fibrous bundles is a very important parameter, especially for industrial applications of textile structures. It is possible to use simulations, particularly for smaller samples. This paper describes the bundle strength of PET filaments from a statistical point of view. The small bundles from 2 till 10 filaments were tested. The simulation-based bundle breaking process combined with bootstrapping was used for estimating bundle strength.

Effects of Accelerated Artificial Daylight Aging on Bending Strength and Bonding of Glass Fibers in Fiber‐Embedded Maxillofacial Silicone Prostheses

The purpose of this study was to test the effect of different periods of accelerated artificial daylight aging on bond strength of glass fiber bundles embedded into maxillofacial silicone elastomer and on bending strength of the glass fiber bundles. Forty specimens were fabricated by embedding resin-impregnated fiber bundles (1.5-mm diameter, 20-mm long) into maxillofacial silicone elastomer. Specimens were randomly allocated into four groups, and each group was subjected to different periods of accelerated daylight aging as follows (in hours); 0, 200, 400, and 600. The aging cycle included continuous exposure to quartz-filtered visible daylight (irradiance 760 W/m(2)) under an alternating weathering cycle (wet for 18 minutes, dry for 102 minutes). Pull-out tests were performed to evaluate bond strength between fiber bundles and silicone using a universal testing machine at 1 mm/min crosshead speed. Also a three-point bending test was performed to evaluate bending strength of the fiber bundles. One-way ANOVA and Bonferroni post hoc tests were carried out to detect statistical significance (p < 0.05). Mean (SD) values of maximum pull-out forces (in N) for groups 1 to 4 were: 13.63 (7.45), 19.67 (1.37), 13.58 (2.61), and 10.37 (2.52). Group 2 exhibited the highest pull-out force that was statistically significant when compared to the other groups. Maximum bending strengths of fiber bundles were in the range of 917.72 MPa to 1124.06 MPa. Bending strength significantly increased after 200 and 400 hours of aging only. After 200 hours of exposure to artificial daylight and moisture conditions, bond strength between glass fibers and heat-cured silicones is optimal, and the bending strength of the glass fiber bundles is enhanced.