The Experts below are selected from a list of 1134 Experts worldwide ranked by ideXlab platform
Jilei Zhang - One of the best experts on this subject based on the ideXlab platform.
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites iv effects of Fiber loadings and aspect ratios on composite tensile properties
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Charles U PittmanAbstract:Mechanically retted short kenaf Bast Fiber bundle (KBFB)–reinforced unsaturated polyester (UPE) composites were fabricated. The effects of Fiber loadings and aspect ratios on composite tensile properties were evaluated experimentally and theoretically. Tensile properties of KBFBs and the neat cured UPE were determined, and kenaf-UPE shear bonding strengths were measured. These measured properties were used to predict the tensile properties of the short KBFB-reinforced UPE composites using classical models in micromechanics. Theoretical tensile moduli predicted by Halpin–Tsai, Mori–Tanaka, and Self-Consistent models were in good agreement with experimental results. Theoretical tensile strengths predicted by the Kelly–Tyson model correlated well with experimental results at high Fiber aspect ratios. Both composite tensile moduli and strengths increased consistently with increasing Fiber loadings up to 75 percent (vol/vol).
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites iii statistical strength characteristics and cost performance analyses
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Charles U PittmanAbstract:The tensile, flexural, and impact strength distribution and the cost-effectiveness of kenaf Bast Fiber bundle (KBFB)- reinforced unsaturated polyester composites were studied. Probability models including normal, two-parameter Weibull, gamma, lognormal, exponential, Burr, Pareto, and inverse Gaussian models were fitted against measured composite strengths. Taking the 5th percentile values as the composite's strength design values, the two-parameter Weibull model provided the most conservative composite strength design values. A cost-effectiveness analysis showed these composites were more cost-effective than glass Fiber-reinforced sheet molding compounds (SMCs) for carrying tensile and flexural loads when their Fiber loadings reached 51.2 and 56.3 percent (wt/wt), respectively. The KBFB-reinforced unsaturated polyester composites were less cost-effective than glass Fiber-reinforced SMCs for carrying impact loads. This work suggests that natural Fiber-reinforced composites have the potential to be viable replacement materials in applications where impact resistance is not critical.
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites ii water resistance and composite mechanical properties improvement
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Chuji Wang, Charles U PittmanAbstract:Water resistance properties of kenaf Bast Fiber bundle (KBFB)–reinforced composites with either unsaturated polyester (UPE) or vinyl ester (VE) matrices, developed in previous research, were studied. The effects of styrene content in UPE resin on the neat UPE resin tensile properties and molding pressure on composite flexural properties were evaluated. The effect of laser and plasma radiation on Fiber-matrix interfacial shear strengths was studied. The composites exhibited high water uptake during short- and long-term water immersion. Encapsulation by surface coating and edge sealing improved composite water resistance. Statistical analyses indicated that molding pressures of 5 to 7 MPa were preferable to achieve the maximum composite mechanical properties, and 37.6 percent (wt/wt) styrene in the UPE resin gave the highest UPE matrix tensile properties in the studied range. Laser and plasma radiation of the KBFBs significantly improved Fiber-matrix interfacial bonding.
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites i processing techniques for high kenaf Fiber loading
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Charles U PittmanAbstract:The fabrication of kenaf Bast Fiber bundle/unsaturated polyester composites with high (60% to 67, wt/wt) Fiber contents was explored in this study. Mechanically ground kenaf Bast Fiber bundles were...
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temperature and loading rate effects on tensile properties of kenaf Bast Fiber bundles and composites
Composites Part B-engineering, 2008Co-Authors: Yicheng Du, Steve Elder, Kunpeng Wang, Jilei ZhangAbstract:Abstract This paper presents extensive experiments and micromechanics-based modeling to evaluate systematically the tensile properties of kenaf Bast Fibers bundle (KBFB) and kenaf Bast Fiber-reinforced epoxy strands. Uniaxial tension behaviors of KBFBs and KBFB-reinforced epoxy strands were evaluated statistically using large sample sets. The elastic modulus, tensile strength, as well as failure strains of KBFBs, displayed large scatter statistically ranging from 10% to 30%. The loading rate-dependency was evaluated at three strain rates ranging from approximately 10−4 ∼ 10−2/s. The tensile strength increases gradually as the loading rate increases, while the tensile modulus almost remains the same as the loading rate increases until the loading rate reaches 10−2/s, at which a much higher modulus was presented. The high temperatures (170–180 °C), possibly subjected during Fiber processing and composite fabrication, do not impose significant effects on the tensile properties of KBFBs if the duration is less than 1-h. The tensile properties of KBFB were not affected by the conditioning at 130 °C for 24-h, which mimics the severe service temperature of automotive front-end components. KBFB-epoxy composite strands were further evaluated at various loading rates. A micromechanics-based Mori–Tanaka model was implemented to predict the anisotropic elastic moduli of KBFB and KBFB-epoxy composite strands based on the microstructural compositions.
Dingxiang Peng - One of the best experts on this subject based on the ideXlab platform.
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transcriptome profiling and identification of transcription factors in ramie boehmeria nivea l gaud in response to peg treatment using illumina paired end sequencing technology
International Journal of Molecular Sciences, 2015Co-Authors: Jie Chen, Lunjin Dai, Bo Wang, Lijun Liu, Jingyu Zhang, Yiwen Liao, Dingxiang PengAbstract:Ramie (Boehmeria nivea L. Gaud), commonly known as China grass, is a perennial Bast Fiber plant of the Urticaceae. In China, ramie farming, industry, and trade provide income for about five million people. Drought stress severely affects ramie stem growth and causes a dramatic decrease in ramie Fiber production. There is a need to enhance ramie’s tolerance to drought stress. However, the drought stress regulatory mechanism in ramie remains unknown. Water stress imposed by polyethylene glycol (PEG) is a common and convenient method to evaluate plant drought tolerance. In this study, transcriptome analysis of cDNA collections from ramie subjected to PEG treatment was conducted using Illumina paired-end sequencing, which generated 170 million raw sequence reads. Between leaves and roots subjected to 24 (L2 and R2) and 72 (L3 and R3) h of PEG treatment, 16,798 genes were differentially expressed (9281 in leaves and 8627 in roots). Among these, 25 transcription factors (TFs) from the AP2 (3), MYB (6), NAC (9), zinc finger (5), and bZIP (2) families were considered to be associated with drought stress. The identified TFs could be used to further investigate drought adaptation in ramie.
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transcriptome profiling using pyrosequencing shows genes associated with Bast Fiber development in ramie boehmeria nivea l
BMC Genomics, 2014Co-Authors: Jie Chen, Zhihua Pei, Lunjin Dai, Bo Wang, Lijun Liu, Dingxiang PengAbstract:Ramie (Boehmeria nivea L.), popularly known as “China grass”, is one of the oldest crops in China and the second most important Fiber crop in terms of area sown. Ramie Fiber, extracted from the plant Bast, is important in the textile industry. However, the molecular mechanism of ramie Fiber development remains unknown. A whole sequencing run was performed on the 454 GS FLX + platform using four separately pooled parts of ramie Bast. This generated 1,030,057 reads with an average length of 457 bp. Among the 58,369 unigenes (13,386 contigs and 44,983 isotigs) that were generated through de novo assembly, 780 were differentially expressed. As a result, 13 genes that belong to the cellulose synthase gene family (four), the expansin gene family (three) and the xyloglucan endotransglucosylase/hydrolase (XTH) gene family (six) were up-regulated in the top part of the Bast, which was in contrast to the other three parts. The identification of these 13 concurrently up-regulated unigenes indicated that the early stage (represented by the top part of the Bast) might be important for the molecular regulation of ramie Fiber development. Further analysis indicated that four of the 13 unigenes from the expansin (two) and XTH (two) families shared a coincident expression pattern during the whole growth season, which implied they were more relevant to ramie Fiber development (Fiber quality, etc.) during the different seasons than the other genes. To the best of our knowledge, this study is the first to characterize ramie Fiber development at different developmental stages. The identified transcripts will improve our understanding of the molecular mechanisms involved in ramie Fiber development. Moreover, the identified differentially expressed genes will accelerate molecular research on ramie Fiber growth and the breeding of ramie with better Fiber yields and quality.
Charles U Pittman - One of the best experts on this subject based on the ideXlab platform.
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites iv effects of Fiber loadings and aspect ratios on composite tensile properties
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Charles U PittmanAbstract:Mechanically retted short kenaf Bast Fiber bundle (KBFB)–reinforced unsaturated polyester (UPE) composites were fabricated. The effects of Fiber loadings and aspect ratios on composite tensile properties were evaluated experimentally and theoretically. Tensile properties of KBFBs and the neat cured UPE were determined, and kenaf-UPE shear bonding strengths were measured. These measured properties were used to predict the tensile properties of the short KBFB-reinforced UPE composites using classical models in micromechanics. Theoretical tensile moduli predicted by Halpin–Tsai, Mori–Tanaka, and Self-Consistent models were in good agreement with experimental results. Theoretical tensile strengths predicted by the Kelly–Tyson model correlated well with experimental results at high Fiber aspect ratios. Both composite tensile moduli and strengths increased consistently with increasing Fiber loadings up to 75 percent (vol/vol).
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites iii statistical strength characteristics and cost performance analyses
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Charles U PittmanAbstract:The tensile, flexural, and impact strength distribution and the cost-effectiveness of kenaf Bast Fiber bundle (KBFB)- reinforced unsaturated polyester composites were studied. Probability models including normal, two-parameter Weibull, gamma, lognormal, exponential, Burr, Pareto, and inverse Gaussian models were fitted against measured composite strengths. Taking the 5th percentile values as the composite's strength design values, the two-parameter Weibull model provided the most conservative composite strength design values. A cost-effectiveness analysis showed these composites were more cost-effective than glass Fiber-reinforced sheet molding compounds (SMCs) for carrying tensile and flexural loads when their Fiber loadings reached 51.2 and 56.3 percent (wt/wt), respectively. The KBFB-reinforced unsaturated polyester composites were less cost-effective than glass Fiber-reinforced SMCs for carrying impact loads. This work suggests that natural Fiber-reinforced composites have the potential to be viable replacement materials in applications where impact resistance is not critical.
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites ii water resistance and composite mechanical properties improvement
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Chuji Wang, Charles U PittmanAbstract:Water resistance properties of kenaf Bast Fiber bundle (KBFB)–reinforced composites with either unsaturated polyester (UPE) or vinyl ester (VE) matrices, developed in previous research, were studied. The effects of styrene content in UPE resin on the neat UPE resin tensile properties and molding pressure on composite flexural properties were evaluated. The effect of laser and plasma radiation on Fiber-matrix interfacial shear strengths was studied. The composites exhibited high water uptake during short- and long-term water immersion. Encapsulation by surface coating and edge sealing improved composite water resistance. Statistical analyses indicated that molding pressures of 5 to 7 MPa were preferable to achieve the maximum composite mechanical properties, and 37.6 percent (wt/wt) styrene in the UPE resin gave the highest UPE matrix tensile properties in the studied range. Laser and plasma radiation of the KBFBs significantly improved Fiber-matrix interfacial bonding.
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kenaf Bast Fiber bundle reinforced unsaturated polyester composites i processing techniques for high kenaf Fiber loading
Forest Products Journal, 2010Co-Authors: Jilei Zhang, Hossein Toghiani, Thomas E Lacy, Yibin Xue, M F Horstemeyer, Charles U PittmanAbstract:The fabrication of kenaf Bast Fiber bundle/unsaturated polyester composites with high (60% to 67, wt/wt) Fiber contents was explored in this study. Mechanically ground kenaf Bast Fiber bundles were...
Michael K. Deyholos - One of the best experts on this subject based on the ideXlab platform.
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Transcriptome Assembly of the Bast Fiber Crop, Ramie, Boehmeria nivea (L.) Gaud. (Urticaceae)
Fibers, 2018Co-Authors: Louay Al-ani, Michael K. DeyholosAbstract:Ramie (Boehmeria nivea) is a perennial crop valued for its strong Bast Fibers. Unlike other major Bast Fiber crops, ramie Fiber processing does not include retting, but does require degumming, suggesting distinctive features in pectin and the development and composition of Fibers. A comprehensive transcriptome assembly of ramie has not been made available, to date. We obtained the sequence of RNA transcripts (RNA Seq) from the apical region of developing ramie stems and combined these with reads from public databases for a total of 157,621,051 paired-end reads (30.3 billion base pairs Gbp) used as input for de novo assembly, resulting in 70,721 scaffolds (≥200 base pairs (bp); N50 = 1798 bp). As evidence of the quality of the assembly, 36,535 scaffolds aligned to at least one Arabidopsis protein (BLASTP e-value ≤ 10−10). The resource described here for B. nivea will facilitate an improved understanding of Bast Fibers, cell wall, and middle lamella development in this and other comparative species.
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engineering Bast Fiber feedstocks for use in composite materials
Biocatalysis and agricultural biotechnology, 2014Co-Authors: Michael K. Deyholos, Simon PotterAbstract:Bast Fibers (i.e. the phloem Fibers of crops such as flax and hemp) have been used for millennia in textiles and cordage and are now promising feedstocks for the production of strong, light weight, renewable composite materials. Several factors limit the broad commercial application of Bast Fibers in composites, including: (i) variability of Fiber properties, (ii) their poor adhesion with conventional resins, (iii) moisture absorption by natural Fibers and (iv) cost of production, especially as this relates to extraction of high-quality Fibers. These problems will be discussed in the context of Fiber developmental biology and of potential solutions enabled by genomics and biotechnology.
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Bast Fiber of flax linum usitatissimum l biological foundations of its ancient and modern uses
Israel Journal of Plant Sciences, 2007Co-Authors: Michael K. DeyholosAbstract:Flax has attracted human attention since at least the New Stone Age (the Neolithic), as one of a few crops from which highly valued products can be extracted from both seeds and straw. In addition to its continued production for linen textiles, flax Fiber is finding new uses in industrial materials, which, along with reported health benefits of flax seed consumption, have created new interest in the biology of Bast Fiber development in this species. Bast Fibers are long and scientifically intriguing cells that undergo intrusive growth and a special process of secondary cell wall assembly. Biochemical and genetic studies are revealing new information about the development of Bast Fibers, and providing a foundation for further manipulation of these unusual cells through biotechnology.
Shouwei Tang - One of the best experts on this subject based on the ideXlab platform.
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de novo assembly and characterization of transcriptome using illumina paired end sequencing and identification of cesa gene in ramie boehmeria nivea l gaud
BMC Genomics, 2013Co-Authors: Touming Liu, Ping Chen, Siyuan Zhu, Qingming Tang, Shouwei TangAbstract:Ramie Fiber, extracted from vegetative organ stem Bast, is one of the most important natural Fibers. Understanding the molecular mechanisms of the vegetative growth of the ramie and the formation and development of Bast Fiber is essential for improving the yield and quality of the ramie Fiber. However, only 418 expressed tag sequences (ESTs) of ramie deposited in public databases are far from sufficient to understand the molecular mechanisms. Thus, high-throughput transcriptome sequencing is essential to generate enormous ramie transcript sequences for the purpose of gene discovery, especially genes such as the cellulose synthase (CesA) gene. Using Illumina paired-end sequencing, about 53 million sequencing reads were generated. De novo assembly yielded 43,990 unigenes with an average length of 824 bp. By sequence similarity searching for known proteins, a total of 34,192 (77.7%) genes were annotated for their function. Out of these annotated unigenes, 16,050 and 13,042 unigenes were assigned to gene ontology and clusters of orthologous group, respectively. Searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG) indicated that 19,846 unigenes were mapped to 126 KEGG pathways, and 565 genes were assigned to http://starch and sucrose metabolic pathway which was related with cellulose biosynthesis. Additionally, 51 CesA genes involved in cellulose biosynthesis were identified. Analysis of tissue-specific expression pattern of the 51 CesA genes revealed that there were 36 genes with a relatively high expression levels in the stem bark, which suggests that they are most likely responsible for the biosynthesis of Bast Fiber. To the best of our knowledge, this study is the first to characterize the ramie transcriptome and the substantial amount of transcripts obtained will accelerate the understanding of the ramie vegetative growth and development mechanism. Moreover, discovery of the 36 CesA genes with relatively high expression levels in the stem bark will present an opportunity to understand the ramie Bast Fiber formation and development mechanisms.
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genetic transformation of the Bast Fiber plant ramie boehmeria nivea gaud via agrobacterium tumefaciens
Plant Cell Tissue and Organ Culture, 2010Co-Authors: Shouwei Tang, Aiguo Zhu, Siyuan Zhu, Sandui Guo, Rui Zhang, Yanzhou Wang, Heping XiongAbstract:Hypocotyls and cotyledons of three ramie (Boehmeria nivea Gaud.) cultivars (Zhongzhu No.1, Zhongsizhu No.1 and NC01), important plants for textile Fiber, were pre-cultured on callus-inducing medium for 1 day before co-cultivation for 2 days with Agrobacterium tumefaciens strain LBA4404 harboring the plasmid pGBI4ABC carrying two insect resistance (CryIA and CpTI), gus, and neomycin phosphotransferase (npt II) genes. Calli were induced from both hypocotyl and cotyledon explants grown on a kanamycin selection medium. Regenerated shoots were obtained after two cycles of culture and transferred to rooting medium. Kanamycin-resistant plantlets were rooted in 2 weeks, and then transplanted to soil. Transgenic plants were subsequently confirmed by polymerase chain reaction, Southern blot hybridization, and GUS assays. More than 100 transgenic plants carrying insect-resistance genes were produced. A transformation frequency of 8.8 to 10.3% was obtained using hypocotyls as explants, which was higher than all previously reported transformation frequencies. The whole protocol, from transformation recovery of plants grown in soil, was completed within 2–4 months. Therefore, a simple, efficient, and robust Agrobacterium tumefaciens -mediated transformation system for ramie has been developed.