scholarly journals The influence of the multi-level structure under high drawing on the preparation of high strength Lyocell fiber

Cellulose ◽  
2022 ◽  
Author(s):  
Shiqiang Cui ◽  
Yang Zhang ◽  
Changjun Liu ◽  
Shanhao Lou ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Level Structure ◽  
High Strength ◽  
Lyocell Fiber ◽  
Multi Level

scholarly journals The Influence of the Multi-level Structure Under High Drawing on the Preparation of High Strength Lyocell Fiber

2021 ◽  
Author(s):  
Shiqiang Cui ◽  
Yang Zhang ◽  
Changjun Liu ◽  
Shanhao Lou ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Draw Ratio ◽  
Breaking Strength ◽  
Level Structure ◽  
High Strength ◽  
X Ray ◽  
Elementary Fibril ◽  
Lyocell Fiber ◽  
Multi Level

Abstract In order to research the multi-level structure of Lyocell fiber at different draw ratios and to reveal the limiting factors for preparing the high strength Lyocell fiber, the paper reports on the effect of draw ratio including low drawing (1–5), high drawing (6–11) and excessive drawing (12–20) on the multi-level structure and the mechanical properties of Lyocell fiber. The structure was determined by wide-angle X-ray diffraction, small-angle X-ray scattering and fibrillation test, and the result showed that, at low draw ratio stage, the breaking strength, yield strength and modulus of the fiber increased with the draw ratio owing to crystallinity as well as orientation increased while the micropore decreased, and there are almost no microfibrils on the fiber surface. At high draw ratio stage, the orientation of amorphous region increasing was the principal reason for the increase of fiber mechanical properties, and the micropores continued to decrease and a few short and thick microfibril was formed. At excessive draw ratio stage, the breaking strength remained constant mainly due to the basically unchanged crystallinity and orientation of the fibers, the yield strength and modulus decreased due to the slip of the highly crystallized and oriented elementary fibril. Meanwhile, the micropores still decreased and became much slenderer, the number of microfibrils increased and the microfibrils showed tenuous structure. It could be summarized that Lyocell fiber had the characteristics of multi-level structure, and the fundamental reason limiting the improvement of mechanical properties with draw ratio increase was the slip of elementary fibril.

scholarly journals Distribution and migration of moisture in round bamboo in response to microwave drying

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5915-5925
Author(s):  
Huang-fei Lv ◽  
Mei-ling Chen ◽  
Cai-ping Lian ◽  
Hui Li ◽  
Shu-min Yang ◽  
...  
Keyword(s):  
Water Content ◽  
Rapid Determination ◽  
Level Structure ◽  
High Strength ◽  
Moisture Distribution ◽  
Microwave Drying ◽  
Key Factor ◽  
Multi Level ◽  
And Migration

Characterized by its light weight, high strength, and good flexibility, round bamboo is a natural functional biomaterial with a multi-level structure. Cracking is a key factor hindering its wider application. Moisture changes cause cracking when the round bamboo is dried. Therefore, studying moisture variations in the drying process of round bamboo can effectively reduce or solve the cracking problem. In this study, microwave drying with computer tomography (CT) imaging technology was used to understand the distribution and migration of moisture in round bamboo in the course of drying. The results indicated that water content has a significant correlation with the CT value, which can be used to achieve rapid determination of water content. The radial water content of samples gradually decreased from bamboo green (outer) to bamboo yellow (inner). The axial water content was high in the middle and low on both ends. As the water content decreased, the axial moisture distribution was consistent. The internode moisture mainly moved from the junction of bamboo yellow and bamboo partition, entered the adjacent cavity, and then gradually moved outward. Thus, the microwave drying method can effectively achieve industrial drying of round bamboo and prevent cracking.

HIGHER ORDER CELLULAR AUTOMATA

2005 ◽  
Vol 08 (02n03) ◽  
pp. 169-192 ◽  
Author(s):  
NILS A. BAAS ◽  
TORBJØRN HELVIK
Keyword(s):  
Dynamical Systems ◽  
Cellular Automata ◽  
Level Structure ◽  
Higher Order ◽  
New Concepts ◽  
Multi Level

We introduce a class of dynamical systems called Higher Order Cellular Automata (HOCA). These are based on ordinary CA, but have a hierarchical, or multi-level, structure and/or dynamics. We present a detailed formalism for HOCA and illustrate the concepts through four examples. Throughout the article we emphasize the principles and ideas behind the construction of HOCA, such that these easily can be applied to other types of dynamical systems. The article also presents new concepts and ideas for describing and studying hierarchial dynamics in general.

1, 1'-Ferrocenedicarboxylic acid/tetrahydrofuran induced precipitation of calcium carbonate with multi-level structure in water

CrystEngComm ◽  
2021 ◽  
Author(s):  
Lihong Zhou ◽  
Guanghui Wang ◽  
Jie Du ◽  
Qinjiang Zhao ◽  
Xiang Pei
Keyword(s):  
Organic Chemistry ◽  
Calcium Carbonate ◽  
Organic Solvent ◽  
Metal Ions ◽  
Level Structure ◽  
Multi Level

The system of organic solvent and ligand had been successfully applied to regulate the coordination of metal ions in organic chemistry. Inspired by previous works, we had conducted the study...

Comparison of Fuzzy and Crisp Versions of an AHP and TOPSIS Model for Nontraditional Manufacturing Process Ranking Decision

2019 ◽  
Vol 18 (02) ◽  
pp. 167-192 ◽  
Author(s):  
Mustafa Yurdakul ◽  
Yusuf Tansel İç
Keyword(s):  
Fuzzy Ahp ◽  
Level Structure ◽  
Selection Procedure ◽  
High Strength ◽  
Fine Tuning ◽  
Attribute Selection ◽  
Machining Processes ◽  
Ranking Model ◽  
Order Preference ◽  
Fuzzy Weights

Nontraditional manufacturing processes (NTMPs) are especially preferred when it is necessary to machine very small and delicate parts, obtain complex shapes or process very hard and high strength materials. New NTMPs are developed continually and the total number of NTMPs being used in the machining industry is increasing so that ranking and selection of the most proper NTMP requires multi-level and systematic models. [M. Yurdakul and C. Cogun, Development of a multi-attribute selection procedure for non-traditional machining processes, Proc. Inst. Mech. Eng. J. Eng. Manuf.217 (2003) 993–1009] developed such an NTMP ranking model. The developed NTMP ranking model in [M. Yurdakul and C. Cogun, Development of a multi-attribute selection procedure for non-traditional machining processes, Proc. Inst. Mech. Eng. J. Eng. Manuf.217 (2003) 993–1009] had a two-level structure and used crisp Analytical Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) together to rank feasible NTMPs. This study aims to replace crisp (nonfuzzy) versions of the AHP and TOPSIS with the fuzzy ones. Application of the fuzzy NTMP ranking model is illustrated and its results are compared with the ones obtained in [M. Yurdakul and C. Cogun, Development of a multi-attribute selection procedure for non-traditional machining processes, Proc. Inst. Mech. Eng. J. Eng. Manuf.217 (2003) 993–1009] to evaluate the significance of the differences in ranking results. The comparisons show that using fuzzy AHP and TOPSIS approaches instead of the crisp ones in the ranking model provided considerable ranking differences. The fuzzy NTMP ranking model is studied furthermore in the paper by updating the NTMP list and fine-tuning fuzzy weights of the pertinent attributes.

scholarly journals Hierarchical Structure, Gelatinization, and Digestion Characteristics of Starch from Longan (Dimocarpus longan Lour.) Seeds

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3262
Author(s):  
Ziman Hu ◽  
Lei Zhao ◽  
Zhuoyan Hu ◽  
Kai Wang
Keyword(s):  
Amylose Content ◽  
Level Structure ◽  
Degree Of Polymerization ◽  
Raw Starch ◽  
Relative Crystallinity ◽  
Digestion Process ◽  
Gelatinized Starch ◽  
Multi Level ◽  
Longan Seed ◽  
Type Crystal

Starch was isolated from longan seeds of three widely distributed cultivars (Chuliang, Shixia, and Caopu) in China. Comparisons of the multi-level structure of the starch of longan seeds among various cultivars were made, and the relations between these structural and property characteristics are discussed. The isolated starch, accounting for 44.9–49.5% (w/w) in longan seeds, had an oval or an irregular polygonal shape with a smooth surface. Their chain-length distributions (CLDs) varied with longan cultivar; Chuliang showed a larger proportion of longer amylopectin chains with a degree of polymerization (DP) 30~100. This is attributed to the slightly higher relative crystallinity of Chuliang longan seed starch. Apparent differences were also detected in amylose structure. Caopu showed a higher amylose content than Chuliang and Shixia, resulting in its lower gelatinization temperatures and enthalpy change. All longan seed starch had a typical A-type crystal structure with relative crystallinity ranging 28.6–28.9%. For raw starch, Caopu showed the lowest digestion rate, followed by Chuliang; Shixia showed the highest. This is because Caopu had the highest amylose content. Chuliang had a more intact structure than Shixia, as suggested by its higher crystallinity, although they had similar amylose content. After being fully gelatinized, all starch showed a similar digestion process, indicating that the digestibility of gelatinized starch does not differ with starch source or structure.

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