Ethephon Improved Stalk Strength of Maize (Zea Mays L.) Mainly through Altering Internode Morphological Traits to Modulate Mechanical Properties under Field Conditions

Stalk strength is critical for reducing maize stalk lodging and maintaining grain yield. Ethephon has been widely applied to molding compact plant-type to reduce the lodging risk in maize production. However, there is little information on how ethephon regulates internode mechanical properties to improve maize stalk strength. Multiyear field experiments (2013–2017) were conducted to determine the effects of foliar-applied ethephon on summer maize internode morphological, chemical and mechanical characteristics. The hypothetical structural equation model was used to analyze the contribution of ethephon-induced changes of internode morphological and chemical traits to stalk mechanical strength. Ethephon significantly reduced the basal internode length, while increasing internode diameters and breaking resistance. Meanwhile, ethephon significantly increased the ratio of structural dry matter to total dry matter and the amount of structural dry matter per unit length and volume. Mechanical assays suggested that ethephon significantly altered geometric properties and increased the maximum bending moment, maximum failure force, while depressing the material properties. Furthermore, correlation and path analyses revealed strong correlations and significant contribution of internode morphological properties to stalk mechanical strength, respectively. These results support the conclusion that ethephon-induced morphology alteration played a major role in improving maize internode strength.

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Effects of Cellulose Nanocrystal and Inorganic Nanofillers on the Morphological and Mechanical Properties of Digital Light Processing (DLP) 3D-Printed Photopolymer Composites

Applied Sciences ◽

10.3390/app11156835 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6835

Author(s):

Sang-U Bae ◽

Birm-June Kim

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Mechanical Strength ◽

Stress Transfer ◽

Cellulose Nanocrystal ◽

Morphological Properties ◽

Precipitated Calcium Carbonate ◽

Digital Light Processing ◽

3D Printed ◽

Cellulose Nanomaterials

Photopolymer composites filled with cellulose nanocrystal (CNC) and/or inorganic nanofillers were fabricated by using digital light processing (DLP) 3D printing. To investigate the effects of different CNC lyophilization concentrations and behaviors of CNC particles in the photopolymer composites, morphological and mechanical properties were analyzed. CNC loading levels affected the morphological and mechanical properties of the filled composites. Better CNC dispersion was seen at a lower lyophilization concentration, and the highest mechanical strength was observed in the 0.25 wt% CNC-filled composite. Furthermore, nano-precipitated calcium carbonate (nano-PCC) and nanoclay were added to photocurable resins, and then the effect of inorganic nanofillers on the morphological and mechanical properties of the composites were evaluated. By analyzing the morphological properties, the stress transfer mechanism of nano-PCC and nanoclay in the photopolymer composites was identified and related models were presented. These supported the improved mechanical strength of the composites filled with CNC, nano-PCC, and nanoclay. This study suggested a new approach using wood-derived cellulose nanomaterials and inorganic nanofillers as effective fillers for DLP 3D printing.

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Measurement of Multiple Mechanical Properties of Fabrics in One Test

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.4480 ◽

2011 ◽

Vol 110-116 ◽

pp. 4480-4486

Author(s):

Zhao Qun Du ◽

Gang Zheng ◽

Hua Shen ◽

Wei Dong Yu

Keyword(s):

Mechanical Properties ◽

Fuzzy Clustering ◽

Clustering Analysis ◽

Unit Length ◽

Bending Moment ◽

Wool Fabric ◽

Bending Rigidity ◽

Shear Properties ◽

Fuzzy Clustering Analysis ◽

Wool Fabrics

The compressibility, bending, weight, friction, tensile and shear properties of wool fabrics and yarns are of vital importance in the hung shape and virtual fitting of end-use textile products. A new apparatus has been developed for characterizing the above mechanical properties of wool fabrics and yarns through a single testing, and the corresponding modeling analysis for compressing, bending, weighting, friction, stretching and shearing properties were conducted and the corresponding characteristics were all measured just through one pulling out testing based on a three-point bending in principal. The compressing measurements for fabric and transversal cross-section yarn were conducted and could obtain the thickness under certain pressure and the low load and thickness curve. The bending modeling for small deflection was developed and adapted to the nonlinear relationship of bending moment and curvature, and the governing differential equation for bending rigidity was found. The weight of fabric in Gram per square meter and the linear density of yarn in Tex per unit length were both effectively and accurately calculated. The friction method was developed based on the Amonton’s Law, and the static and dynamic frictional coefficients were found. The tensile and shear properties under low stress were investigated and the corresponding characteristics, such as elastic modulus and shearing modulus, were obtained. Moreover, the fuzzy clustering analysis for handle of fabrics or yarns was utilized to classify and further verify the measured fabrics or yarns based on the mechanical properties mentioned above. Thereof, the comprehensive handle system for fabrics and yarns (briefly named CHS-FY) was necessarily self-designed and utilized to characterize the mechanical properties, which played a crucial role in quickly classifying the fabrics and yarns with different style. Meanwhile, the verifications of the comprehensive handle system for fabric and yarn was conducted, and indicated that there were in good agreement between theoretical and experimental results of mechanical properties of wool fabric and yarn, and showed that there existed high accuracy in classification with the fuzzy clustering analysis. Thereby, the comprehensive handle system for wool fabrics and yarns is effective and accurate in measuring the compressibility, bending, weight, friction, tensile and shear properties and fast classifying the handle of wool fabrics and yarns.

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Effect of Polymer Concentration on the Morphology and Mechanical Properties of Asymmetric Polysulfone (PSf) Membrane

Journal of Applied Membrane Science & Technology ◽

10.11113/amst.v21i1.107 ◽

2017 ◽

Vol 21 (1) ◽

Cited By ~ 1

Author(s):

N. M. Ismail ◽

N. R. Jakariah ◽

N. Bolong ◽

S. M. Anissuzaman ◽

N. A. H. M. Nordin ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Mechanical Strength ◽

Polymer Concentration ◽

Membrane Properties ◽

Morphological Properties ◽

Elongation At Break ◽

Membrane Morphology ◽

Tensile Tester ◽

Morphology And Mechanical Properties

Polymer concentration had been identified as one of the important parameters tailoring the membrane properties. In this work, the effects of polymer concentration on the morphological and mechanical properties of membrane were investigated at three different polymer concentrations, i.e., 20, 25 and 30 wt%. The viscosity of dope solutions were determined to estimate the optimum polymer concentration. The morphological properties of the fabricated membrane were determined using SEM whereas the mechanical properties of the membrane were investigated using tensile tester. Results show that an increase in the polymer concentration could lead to the improvement of the morphological and mechanical properties of the membrane. The tensile strength of the membrane determined for PSf-20, PSf-25 and PSf-30 are 5.73, 6.59 and 7.03 MPa, respectively whereas the elongation at break measured for the membranes are 46.99%, 69.18% and 36.27%, respectively. As shown in this work, the polymer concentration played a significant role to alter on membrane morphology and mechanical strength.

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Idiographic Dynamics of Positive Affect in GAD

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000580 ◽

2020 ◽

Vol 36 (3) ◽

pp. 500-509

Author(s):

Hannah G. Bosley ◽

Devon B. Sandel ◽

Aaron J. Fisher

Keyword(s):

Positive Affect ◽

Structural Equation ◽

Alternative Hypothesis ◽

Equation Model ◽

Aggregated Data ◽

Regulatory Strategy ◽

Constant State ◽

Automatic Search ◽

Time Lagged ◽

Exploratory Procedure

Abstract. Generalized anxiety disorder (GAD) is associated with worry and emotion regulation difficulties. The contrast-avoidance model suggests that individuals with GAD use worry to regulate emotion: by worrying, they maintain a constant state of negative affect (NA), avoiding a feared sudden shift into NA. We tested an extension of this model to positive affect (PA). During a week-long ecological momentary assessment (EMA) period, 96 undergraduates with a GAD analog provided four daily measurements of worry, dampening (i.e., PA suppression), and PA. We hypothesized a time-lagged mediation relationship in which higher worry predicts later dampening, and dampening predicts subsequently lower PA. A lag-2 structural equation model was fit to the group-aggregated data and to each individual time-series to test this hypothesis. Although worry and PA were negatively correlated in 87 participants, our model was not supported at the nomothetic level. However, idiographically, our model was well-fit for about a third (38.5%) of participants. We then used automatic search as an idiographic exploratory procedure to detect other time-lagged relationships between these constructs. While 46 individuals exhibited some cross-lagged relationships, no clear pattern emerged across participants. An alternative hypothesis about the speed of the relationship between variables is discussed using contemporaneous correlations of worry, dampening, and PA. Findings suggest heterogeneity in the function of worry as a regulatory strategy, and the importance of temporal scale for detection of time-lagged effects.

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Differential Item Functioning in Brief Instruments of Disordered Eating

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000472 ◽

2019 ◽

Vol 35 (6) ◽

pp. 823-833 ◽

Cited By ~ 4

Author(s):

Desiree Thielemann ◽

Felicitas Richter ◽

Bernd Strauss ◽

Elmar Braehler ◽

Uwe Altmann ◽

...

Keyword(s):

Differential Item Functioning ◽

Disordered Eating ◽

Structural Equation ◽

Young Female ◽

Eating Attitudes ◽

Equation Model ◽

German Population ◽

Test Fairness ◽

Item Functioning ◽

Multiple Indicator

Abstract. Most instruments for the assessment of disordered eating were developed and validated in young female samples. However, they are often used in heterogeneous general population samples. Therefore, brief instruments of disordered eating should assess the severity of disordered eating equally well between individuals with different gender, age, body mass index (BMI), and socioeconomic status (SES). Differential item functioning (DIF) of two brief instruments of disordered eating (SCOFF, Eating Attitudes Test [EAT-8]) was modeled in a representative sample of the German population ( N = 2,527) using a multigroup item response theory (IRT) and a multiple-indicator multiple-cause (MIMIC) structural equation model (SEM) approach. No DIF by age was found in both questionnaires. Three items of the EAT-8 showed DIF across gender, indicating that females are more likely to agree than males, given the same severity of disordered eating. One item of the EAT-8 revealed slight DIF by BMI. DIF with respect to the SCOFF seemed to be negligible. Both questionnaires are equally fair across people with different age and SES. The DIF by gender that we found with respect to the EAT-8 as screening instrument may be also reflected in the use of different cutoff values for men and women. In general, both brief instruments assessing disordered eating revealed their strengths and limitations concerning test fairness for different groups.

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The Influence of Cognitive and Affective Reactions to Feedback on Subsequent Goals

European Psychologist ◽

10.1027/1016-9040/a000011 ◽

2010 ◽

Vol 15 (2) ◽

pp. 121-131 ◽

Cited By ~ 20

Author(s):

Remus Ilies ◽

Timothy A. Judge ◽

David T. Wagner

Keyword(s):

Performance Feedback ◽

Business School ◽

Structural Equation ◽

Emotional Reactions ◽

Equation Model ◽

Proposed Model ◽

And Performance ◽

Dispositional Measure ◽

The Relationship ◽

Reactions To Feedback

This paper focuses on explaining how individuals set goals on multiple performance episodes, in the context of performance feedback comparing their performance on each episode with their respective goal. The proposed model was tested through a longitudinal study of 493 university students’ actual goals and performance on business school exams. Results of a structural equation model supported the proposed conceptual model in which self-efficacy and emotional reactions to feedback mediate the relationship between feedback and subsequent goals. In addition, as expected, participants’ standing on a dispositional measure of behavioral inhibition influenced the strength of their emotional reactions to negative feedback.

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Forced Zero Cross-Loading Misspecifications in Measurement Component of Structural Equation Models

Methodology ◽

10.1027/1614-2241/a000084 ◽

2014 ◽

Vol 10 (4) ◽

pp. 138-152 ◽

Cited By ~ 5

Author(s):

Hsien-Yuan Hsu ◽

Susan Troncoso Skidmore ◽

Yan Li ◽

Bruce Thompson

Keyword(s):

Structural Equation ◽

Structural Model ◽

Structural Equation Models ◽

Equation Model ◽

Model Fit ◽

Model Specification ◽

Simulation Design ◽

Measurement Models ◽

Fit Statistics ◽

Path Coefficients

The purpose of the present paper was to evaluate the effect of constraining near-zero parameter cross-loadings to zero in the measurement component of a structural equation model. A Monte Carlo 3 × 5 × 2 simulation design was conducted (i.e., sample sizes of 200, 600, and 1,000; parameter cross-loadings of 0.07, 0.10, 0.13, 0.16, and 0.19 misspecified to be zero; and parameter path coefficients in the structural model of either 0.50 or 0.70). Results indicated that factor pattern coefficients and factor covariances were overestimated in measurement models when near-zero parameter cross-loadings constrained to zero were higher than 0.13 in the population. Moreover, the path coefficients between factors were misestimated when the near-zero parameter cross-loadings constrained to zero were noteworthy. Our results add to the literature detailing the importance of testing individual model specification decisions, and not simply evaluating omnibus model fit statistics.

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