Increasing Fiber Length Research Articles

Optical pulse evolution in the presence of a probe light in CW-pumped nonlinear fiber**Project supported by the National Natural Science Foundation of China (Grant No. 61505258) and the Scientific Research Project of National University of Defense Technology (Grant No. JC15-11-02).

We investigate theoretically and numerically the evolutions of optical pulses in the time domain due to modulation instability (MI), where CW pump accompanied with a probe is used as the input of nonlinear fiber. As the fiber length increases, we show that it exhibits beat frequency between the pump and the probe first when the probe lies outside the MI resonance region, and then gradually transforms into a pulse train resulting from spontaneous MI rather than induced MI. However, the regular pulse train is easier to generate in the whole fiber if the probe exists in MI resonance region, and the period of the pulse train is inversely proportional to the frequency spacing between the pump and the probe. It is emphasized that the pulse period can be adjusted only when the probe is in MI resonance region. The numerical simulations are in agreement with the theoretical results. The obtained results are guidable for generating and manipulating the optical pulse train in the fiber.

Steady-state Performance Analysis of Brillouin Fiber Optic Gyroscope Ring Resonator

Aiming at the requirement of Stimulated Brillouin fiber optic gyroscope, the characteristics of Stimulated Brillouin ring resonator are investigated, and obtain the stead-state performance when resonance. The relationship between the first stokes light power and input light is obtained after optimzation, and also analyze the influence of resonator on the characteristics of the Stokes light power. Simulation results show that when the input pump power reaches the Stimulated Brillouin threshold, first Stokes light is obtained. And the power of stokes light increases with increasing fiber length.

Effectiveness of recycled nylon fiber from waste fishing net with respect to fiber reinforced mortar

This paper discusses the utilization of recycle waste fishing nets in fiber reinforced mortar. Experimental test results compared the mechanical properties of such mortar made with recycled nylon fiber to those of such mortar made with recycled PET and PVA (polyvinyl alcohol) short fibers. The recycled nylon (R-Nylon) fibers were obtained by manually cutting of waste fishing nets to the lengths of 20mm, 30mm and 40mm. Two types of R-Nylon fibers were investigated that are straight and knotted types. The addition of straight R-Nylon fiber improved the flexural strength up to 41% in comparison with that of the knotted R-Nylon, recycled PET, and PVA fibers. The compressive strength of the mortar with R-Nylon fiber decreased with increase in fiber fraction and length. The post peak load, toughness and residual strength depended on the properties of fiber such as Young’s modulus, tensile strength, and geometry as well as the bond strength between fiber and matrix.

Fine mapping and candidate gene analysis of qFL-chr1, a fiber length QTL in cotton.

A fiber length QTL, qFL-chr1, was fine mapped to a 0.9cM interval of cotton chromosome 1. Two positional candidate genes showed positive correlation between gene expression level and fiber length. Prior analysis of a backcross-self mapping population derived from a cross between Gossypium hirsutum L. and G. barbadense L. revealed a QTL on chromosome 1 associated with increased fiber length (qFL-chr1), which was confirmed in three independent populations of near-isogenic introgression lines (NIILs). Here, a single NIIL, R01-40-08, was used to develop a large population segregating for the target region. Twenty-two PCR-based polymorphic markers used to genotype 1672 BC4F2 plants identified 432 recombinants containing breakpoints in the target region. Substitution mapping using 141 informative recombinants narrowed the position of qFL-chr1 to a 1.0-cM interval between SSR markers MUSS084 and CIR018. To exclude possible effects of non-target introgressions on fiber length, different heterozygous BC4F3 plants introgressed between SSR markers NAU3384 and CGR5144 were selected to develop sub-NILs. The qFL-chr1 was further mapped at 0.9-cM interval between MUSS422 and CIR018 by comparisons of sub-NIL phenotype, and increased fiber length by ~1mm. The 2.38-Mb region between MUSS422 and CIR018 in G. barbadense contained 19 annotated genes. Expression levels of two of these genes, GOBAR07705 (encoding 1-aminocyclopropane-1-carboxylate synthase) and GOBAR25992 (encoding amino acid permease), were positively correlated with fiber length in a small F2 population, supporting these genes as candidates for qFL-chr1.

Measurement for optical arbitrary waveforms using cross-phase modulation cross-correlation frequency-resolved optical gating in a single-mode fibre

A novel scheme of cross-correlation frequency-resolved optical gating (X-FROG) measurement for optical arbitrary waveforms based on the photo-elastic effect and cross-phase modulation (XPM) effect in a single-mode fibre is proposed. In this scheme, a variable delay is generated in the former part of the single-mode fibre by a uniform lateral pressure, and the XPM effect is achieved in the latter part of the fibre. The proposed scheme is very simple and easy to be realized. The amplitude and phase of optical arbitrary waveform to be measured is retrieved from the X-FROG trace using principal component generalized projects algorithm based on matrix. The impacts of the shape of gate pulse, fibre length, relative intensity between gate pulse and optical arbitrary waveform and the complexity of the optical arbitrary waveform on the accuracy of retrieved amplitude and phase are investigated. Simulation results show that, rectangular pulse is a better gate pulse due to lower errors. The accuracy of measurement is improved with the increase in fibre length, and relative intensity between gate pulse and optical arbitrary waveform. Moreover, this scheme also can be used to measure extremely complex optical arbitrary waveforms.

The cotton β-galactosyltransferase 1 (GalT1) that galactosylates arabinogalactan proteins participates in controlling fiber development.

Arabinogalactan proteins (AGPs) are highly glycosylated proteins that play pivotal roles in diverse developmental processes in plants. Type-II AG glycans, mostly O-linked to the hydroxyproline residues of the protein backbone, account for up to 95% w/w of the AGP, but their functions are still largely unclear. Cotton fibers are extremely elongated single-cell trichomes on the seed epidermis; however, little is known of the molecular basis governing the regulation of fiber cell development. Here, we characterized the role of a CAZy glycosyltransferase 31 (GT31) family member, GhGalT1, in cotton fiber development. The fiber length of the transgenic cotton overexpressing GhGalT1 was shorter than that of the wild type, whereas in the GhGalT1-silenced lines there was a notable increase in fiber length compared with wild type. The carbohydrate moieties of AGPs were altered in fibers of GhGalT1 transgenic cotton. The galactose: arabinose ratio of AG glycans was higher in GhGalT1 overexpression fibers, but was lower in GhGalT1-silenced lines, compared with that in the wild type. Overexpression of GhGalT1 upregulates transcript levels of a broad range of cell wall-related genes, especially the fasciclin-like AGP (FLA) backbone genes. An enzyme activity assay demonstrated that GhGalT1 is a β-1,3-galactosyltransferase (β-1,3-GalT) involved in biosynthesis of the β-1,3-galactan backbone of the type-II AG glycans of AGPs. We also show that GhGalT1 can form homo- and heterodimers with other cotton GT31 family members to facilitate AG glycan assembly of AGPs. Thus, our data demonstrate that GhGalT1 influences cotton fiber development via controlling the glycosylation of AGPs, especially FLAs.

Micromechanics constitutive modelling and optimization of strain hardening geopolymer composite

This paper investigates the micromechanics constitutive modelling and optimization of a fiber-reinforced strain-hardening geopolymer composite (SHGC) recently developed by the authors. Micromechanical parameters of the developed fly ash-based SHGC were independently measured or deduced to compute the analytical crack bridging (σ-δ) relation of the composite. The predicted σ-δ relation was compared with the experimental test results. It was confirmed that the previously developed micromechanics-based model can reasonably predict the σ-δ relation of fly ash-based SHGCs. Using the verified model, a parametric study was then performed to evaluate the effects of fiber length, fiber surface oil-coating, and matrix fracture toughness on critical (minimum) fiber content required to exhibit saturated pseudo strain-hardening (PSH) behavior. The results indicated that the critical fiber content in fly ash-based SHGCs is mainly governed by the energy-based criterion. It was demonstrated that the fiber surface oil coating, the increase of fiber length and the reduction of matrix fracture toughness are effective approaches to reduce the critical fiber content. Using the model, it was demonstrated that fly ash-based SHGCs can be systematically optimized by proper tailoring of the material constituents to achieve saturated PSH behavior with the lowest amount of fiber, and thereby the lowest cost.

Feasibility of Reducing the Fiber Content in Ultra-High-Performance Fiber-Reinforced Concrete under Flexure.

In this study, the flexural behavior of ultra-high-performance fiber-reinforced concrete (UHPFRC) is examined as a function of fiber length and volume fraction. Straight steel fiber with three different lengths (lf) of 13, 19.5, and 30 mm and four different volume fractions (vf) of 0.5%, 1.0%, 1.5%, and 2.0% are considered. Test results show that post-cracking flexural properties of UHPFRC, such as flexural strength, deflection capacity, toughness, and cracking behavior, improve with increasing fiber length and volume fraction, while first-cracking properties are not significantly influenced by fiber length and volume fraction. A 0.5 vol % reduction of steel fiber content relative to commercial UHPFRC can be achieved without deterioration of flexural performance by replacing short fibers (lf of 13 mm) with longer fibers (lf of 19.5 mm and 30 mm).

A modified method for determining the focal ratio degradation and length properties of optical fibres in astronomy

Focal ratio degradation (FRD) is a major contributor to throughput and light loss in a fibre spectroscopic telescope system. We combine the guided mode theory in geometric optics and a well-known model, power distribution model (PDM), to predict and explain the FRD dependence properties. We present a robust method by modifying the energy distribution method (EDM) with \emph{f-intercept} to control the input condition. This method provides a way to determine the proper position of the fibre end on the focal plane to improve energy utilization and FRD performance, which lifts the relative throughput up to 95\% with variation of output focal ratio less than 2\%. And this method can also help to optimize the arrangement of the position of focal-plane plate to enhance the coupling efficiency in a telescope. To investigate length properties, we modified PDM by introducing a new parameter, focal distance \emph{f}, into the original model to make it available for multi-position measurement system. The results show that the modified model is robust and feasible for measuring the key parameter \emph{d}$_0$ to simulate the transmission characteristics. The output focal ratio in the experiment does not follow the prediction trend but shows an interesting phenomenon that the output focal ratio increases at first to the peak, then decreases and remains stable finally with increasing fibre length longer than 15m, which provides a reference for choosing appropriate length of fibre to improve the FRD performance for the design of the fibre system in a telescope.

Effect of fiber length on formation and strength efficiency in twin-wire roll forming

A change in fiber length is known to change fiber flocculation and formation of machine-made paper, but it has been unclear how a change in formation through fiber length affects strength efficiency. (The strength efficiency reflects how well the furnish strength, as indicated by the handsheet strength, is utilized in the machine-made paper.) The effect of fiber length on strength efficiency in twin-wire roll forming was presently investigated by examining two furnishes with different average fiber length, prepared from the same batch of softwood kraft pulp, over a wide range of headbox consistencies on a pilot machine. An increase in fiber length resulted not only in worse Ambertec formation over the whole range of headbox consistencies but also in faster relative deterioration of the formation with increasing consistency. Tensile strength efficiency and Z-strength efficiency were both reduced when the formation was impaired through increased fiber length, and the effect was similar to the effect of a corresponding change in formation through headbox consistency. A given change in formation, through fiber length or headbox consistency, had a larger relative effect on Z-strength efficiency than on tensile strength efficiency.

Effects of Coir Fiber Loading on the Physio-mechanical and Morphological Properties of Coconut Shell Powder Filled Low Density Polyethylene Composites

Coconut shell filled composites were prepared from recycled low density polyethylene polymer matrix containing up to 15% weight of coconut shell powder as filler. The effect of coir fiber loading on the properties of the composites was then investigated. It was shown that the values of tensile strength, flexural strength and hardness increased up to 7.1MN/m2,18.0GPa and 92.7 respectively. Impact energy decreased with increase in fiber length. With the introduction of fiber length from zero to 10mm, a decrease in density and increase in water absorption was observed.

Carrier Suppressed Return-to-Zero (CSRZ) and Modified Duobinary Return- to- Zero (MDRZ) Advance Optical Modulation Formats Analysis for Long Haul Rural Coverage

The rapid increase in the usage of data communication and data consuming devices demands higher data rate and reliable communication. In order to meet these demands new technologies are required which will be able to provide optimal quality of service and higher data rates. Next-Generation optical networks promise fast and flexible connectivity to resolve above challenging demands and can provide enough capacity for the next few years but the increase in data rate and transmission distance causes increase in dispersion. It occurs when different frequencies or mode of light in optical fiber are received by the terminals at different time and it increases, with an increase in fiber length. This is the major cause for breaking down quality of signal in optical fiber. Different modulation techniques are used to reduce the effect of dispersion, and improve the performance of the optical system. In this work, Performance of Carrier Suppressed Return-to-Zero (CSRZ) & Modified Duobinary Return-to-Zero (MDRZ) Advance Optical Modulation Formats are investigated in terms of Eye Height, Bit Error Rate (BER) and Quality Factor at 2Gbps for two different lengths of fiber in Optisystem. It found that MDRZ gives dispersion less transmission and less BER for long distance transmission.

Carrier Suppressed Return-to-Zero (CSRZ) and Modified Duobinary Return- to- Zero (MDRZ) Advance Optical Modulation Formats Analysis for Long Haul Rural Coverage

The rapid increase in the usage of data communication and data consuming devices demands higher data rate and reliable communication. In order to meet these demands new technologies are required which will be able to provide optimal quality of service and higher data rates. Next-Generation optical networks promise fast and flexible connectivity to resolve above challenging demands and can provide enough capacity for the next few years but the increase in data rate and transmission distance causes increase in dispersion. It occurs when different frequencies or mode of light in optical fiber are received by the terminals at different time and it increases, with an increase in fiber length. This is the major cause for breaking down quality of signal in optical fiber. Different modulation techniques are used to reduce the effect of dispersion, and improve the performance of the optical system. In this work, Performance of Carrier Suppressed Return-to-Zero (CSRZ) & Modified Duobinary Return-to-Zero (MDRZ) Advance Optical Modulation Formats are investigated in terms of Eye Height, Bit Error Rate (BER) and Quality Factor at 2Gbps for two different lengths of fiber in Optisystem. It found that MDRZ gives dispersion less transmission and less BER for long distance transmission.

Effect of polyamines on mechanical and structural properties of Bombyx mori silk.

Silkworm, Bombyx mori (B. mori) belongs to the Lepidoptera family. The silk produced from this insect, mulberry silk, gained lot of importance as a fabric. Silk is being exploited as a biomaterial due to its surprising strength and biocompatibility. Polyamines (PA) are important cell growth regulators. In the present work the effect of treatment of polyamines, putrescine (Put), spermidine (Spd), and spermine (Spm) on the quantity and quality of silk produced was assessed. Results showed that exogenous feeding of Spd at a concentration of 50 µM increased fiber length significantly. Analysis by Fourier transform infrared (FTIR) on the properties of silk obtained from Spd treated silkworms revealed an increase in percentage of absorption with no difference in peak positions of amide I and amide III groups. Scanning electron microscopy (SEM) revealed an increase in diameter of silk. Further, analysis at molecular level showed an increase in fibroin expression in Spd treated silk glands. However, the Spd treatment showed no significant difference with respect to fibroin to sericin ratio per unit weight of cocoon, silk tenacity, and percent elongation. Thus, the present results show that polyamine treatment would influence silk quality at structural, mechanical, and molecular level in the Bombyx mori, which can be exploited in silk biomaterial production.

In silico investigation of factors affecting the MV imaging performance of a novel water-equivalent EPID

PurposeA Geant4 model of a novel, water-equivalent electronic portal imaging device (EPID) prototype for radiotherapy imaging and dosimetry utilising an array of plastic scintillating fibres (PSFs) has been developed. Monte Carlo (MC) simulations were performed to quantify the PSF-EPID imaging performance and to investigate design aspects affecting performance for optimisation. MethodsUsing the Geant4 model, the PSF-EPID’s imaging performance for 6 MV photon beams was quantified in terms of its modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE). Model parameters, including fibre dimensions, optical cladding reflectivity and scintillation yield, were varied to investigate impact on imaging performance. ResultsThe MC-calculated DQE(0) for the reference PSF-EPID geometry employing 30mm fibres was approximately nine times greater than values reported for commercial EPIDs. When using 10mm long fibres, the PSF-EPID DQE(0) was still approximately three times greater than that of a commercial EPID. Increased fibre length, cladding reflectivity and scintillation yield produced the greatest decreases in NPS and increases in DQE. ConclusionsThe potential to develop an optimised next-generation water-equivalent EPID with MV imaging performance at least comparable to commercial EPIDs has been demonstrated. Factors most important for optimising prototype design include fibre length, cladding reflectivity and scintillation yield.

Analisa Kekuatan Tarik dan Bending pada Komposit Widuri-Polyester

The purpose of this study to analyze the tensile strength and flexural strength of widuri fiber reinforced polyester. Treatment with 5% NaOH for 1 hour. Directions random fiber orientation with a fiber size of 1 cm, 3 cm and 5 cm. The test specimen is printed with a printing press method, the fiber volume fraction of 30%, polyester resin binder. The test specimens were performed according to ASTM testing standard ASTM D638 to for tensile and D790 to flexural test. The calculation result obtained an increase in the tensile strength fiber length of 5 cm is 43.0809 MPa. While the value of the highest tensile modulus of elasticity of the fiber length of 3 cm. While testing the flexural obtained the highest bending strength in the fiber length of 3 cm is 62.8874 MPa and flexural strength values were lower in fiber length of 5 cm. While the value of the highest flexural modulus of elasticity of 3.1325 MPa with a fiber length of 5 cm and the lowest fiber length of 3 cm, for the highest value of 6509.916 Nmm flexural moments on the fiber length of 3 cm and the lowest value of flexural moment of the fiber length of 1 cm. From the results of photo fracturing shape tensile test specimens showed that the fiber length of 1 cm, 3 cm, 5 cm is a fault caused by a failure in the weight-bearing matrix. The images form flexural fracture test specimens showed that the fiber length of 5 cm is a fault caused by a failure in the weight-bearing matrix, whereas the fiber length of 1 cm and 3 cm showed the form fracture caused by the failure of fiber in weight-bearing

An experimental study on random fiber mixed granular pile

Granular pile (GP) is one of the ground improvement techniques. Randomly mixed fiber GP in place of plain GP is a new development. In this paper some parametric studies on randomly mixed fiber GP have been presented in order to evaluate the effect of fiber content, fiber length and depth of sand-random fiber mixture in GP on load carrying capacity and other characteristics of GP. Significant improvement in load carrying capacity of soft clay bed has been observed with the increase in fiber content, fiber length and depth of sand-random fiber mixture in the GP. An equation has been developed by regression analysis to estimate the load carrying capacity of randomly mixed fiber GP. The findings of this model study indicate that the random fiber-reinforced GP may open a new option in the field of ground improvement techniques.

Femtosecond laser inscribed Bragg grating arrays in long lengths of polymer optical fibres; a route to practical sensing with POF

The first practical demonstration of readily useable fibre Bragg gratings in long lengths (>20 m) of polymer optical fibres (POFs) is reported; this is an increase in fibre length that exceeds two orders of magnitude for use in the C-band. A low loss perfluorinated fibre and a femtosecond-laser, direct-write method to inscribe gratings at two different wavelengths are used. Gratings are fabricated to operate at ∼800 nm, where the optical loss is minimal, and in the C-band, commonly used with traditional optical fibres for the majority of telecommunication applications. The development of POF Bragg gratings inscribed in long fibre lengths is the first important step for the integration of practical sensing devices and could promote the use of multiplexed POF sensors. The sensors were tested and characterised and demonstrate their compatibility with a commercial Bragg grating demodulator.

Within‐Season Growth and Spectral Reflectance of Cotton and their Relation to Lint Yield

Within‐season measurements of cotton (Gossypium hirsutum L.) growth and development in response to moisture deficit stress can provide insight into how management practices impact plant health and yield. The objectives were to investigate responses of leaf area index (LAI), normalized difference vegetation index (NDVI), normalized difference water index (NDWI), and crop water stress index (CWSI) and their relation to the lint yield of four cotton cultivars (PHY499, DP1044, PHY375, and FM9170) grown under various irrigation levels for two consecutive growing seasons at Chillicothe, TX. Plants exposed to water stress showed significant LAI, NDVI, and NDWI decrease and CWSI increase compared with well‐watered plants. The NDVI reached a plateau value of 0.89 at 82 d after planting (DAP), while NDWI increased steadily to the end of the growing seasons for the high irrigation level. The high irrigation level had the greatest lint yield of 1670 and 1846 kg ha−1 in 2013 and 2014, respectively. Fiber length, strength, and micronaire showed significant differences among irrigation levels. Compared with dryland, an average 8% increase in fiber length and strength and 10% decrease in micronaire were observed by the high irrigation level. High positive correlations of LAI, NDVI, and NDWI with lint yield were observed in both years. The CWSI differentiated low vs. high irrigated plants and was negatively correlated with lint yield. The results indicated that these measurements at different growth stages are useful to detect growth and water status for cotton in the semiarid Texas Rolling Plains.

Application of an Automatic Yarn Dismantler to Track Changes in Cotton Fiber Properties during Full Scale Processing of Cotton into Carded Yarn

ABSTRACTChanges in Upland cotton fiber properties from lint to carded yarn, during full scale processing, were tracked, using a newly developed automatic yarn dismantler for dismantling short staple ring-spun yarns. Opening and cleaning increased fiber neps significantly, and short fiber content (SFC) slightly, and decreased fiber length slightly, whereas the card increased fiber length, and decreased neps substantially. Fiber length decreased during spinning, indicating significant fiber breakage. The length of fibers from dismantled yarn was higher, and SFC lower, than that in the twistless strand before twist insertion, indicating that, during twist insertion, short fibers were lost as fly and through suction. Fiber linear density and maturity showed similar trends, changing little during opening and cleaning, but then increasing consistently up to the roving stage.