scholarly journals Maize brace root biomechanics are determined by geometry within a genotype and material properties between genotypes

2019 ◽  
Author(s):  
Lindsay Erndwein ◽  
Elahe Ganji ◽  
Ashley N. Hostetler ◽  
Adam Stager ◽  
Megan L. Killian ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Zea Mays ◽  
Material Properties ◽  
Growth Stage ◽  
Yield Loss ◽  
Mechanical Stability ◽  
Bending Tests ◽  
Bending Modulus ◽  
Root Biomechanics

ABSTRACTCrop plants are susceptible to yield loss by mechanical failure, which is called lodging. In maize (Zea mays), aerial nodal brace roots impart mechanical stability to plants, with previous studies showing that the lowest whorl of brace roots contributes the most. The features of brace roots that determine their contribution to mechanical stability are poorly defined. Here we tested the hypothesis that brace root mechanical properties vary between whorls, which may influence their contribution to mechanical stability. 3-point bending tests were used to determine that brace roots from the lowest whorl have the highest structural mechanical properties regardless of growth stage, and that these differences are largely due to brace root geometry within a genotype. Analysis of the brace root bending modulus determined that differences between genotypes are attributable to both geometry and material properties. These results support the role of brace root biomechanics to determine the brace root contribution to mechanical stability.HIGHLIGHTBrace root biomechanics vary within and between genotypes. These results support the importance of biomechanics to define the contribution of brace roots to mechanical stability.

Safening Influence of LAB 145 138 on Nicosulfuron, Terbufos and Bentazon Interactions in Sweet Corn (Zea mays)

Weed Science ◽  
1996 ◽  
Vol 44 (2) ◽  
pp. 339-344 ◽  
Author(s):  
Darren K. Robinson ◽  
David W. Monks ◽  
James D. Burton
Keyword(s):  
Zea Mays ◽  
Seed Treatment ◽  
Growth Stage ◽  
Yield Loss ◽  
Sweet Corn ◽  
Leaf Growth ◽  
Growth Stages ◽  
Height Reduction ◽  
Reduced Height ◽  
Previously Treated

LAB 145 138 (LAB) was evaluated as a safener to improve sweet corn tolerance to nicosulfuron applied POST alone or with terbufos applied in the planting furrow or bentazon applied POST. To ensure enhanced injury for experimental purposes, nicosulfuron was applied at twice the registered rate alone or mixed with bentazon at the six- to seven-leaf growth stage of corn previously treated with the highest labeled rate of terbufos 15 G formulation. LAB applied as a seed treatment (ST) or POST at the two- to three-, four- to five-, or six- to seven-leaf growth stages reduced height reduction and yield loss from nicosulfuron applied POST in combination with terbufos applied in-furrow. LAB applied POST at the four- to five-leaf growth stage was most effective in preventing injury from this treatment, with yield reduced only 8% compared with 54% from the nicosulfuron and terbufos treatment. LAB applied POST at the eight- to nine-leaf growth stage did not alleviate injury. With the nicosulfuron, terbufos, and bentazon combination, LAB applied POST at the three- to four- or six- to seven-leaf growth stages decreased height reduction and yield loss caused by this combination, with LAB at the three- to four-leaf growth stage being most effective.

Modification of DABA/BMI Composites by Silane Compound and Fumed SiO2

2012 ◽  
Vol 622-623 ◽  
pp. 1006-1013
Author(s):  
Nazakat Alia ◽  
Qiu Yu Zhang ◽  
Yin Wu ◽  
Ying Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Thermal Properties ◽  
Fumed Silica ◽  
Heat Stability ◽  
Nano Composite ◽  
Bending Modulus ◽  
Scanning Electron

In this present investigation, at first, Dially bisphenol A (DABA)/Bismaleimide (BMI) system was modified with gamma-aminopropyltriethoxy silane (KH550). The objective of the work was to study the effect of addition of various weight percentages of KH550 into BMI/DABA composites on its mechanical properties, thermal properties and morphorogy. Further modification was carried out with fumed silica. The role of KH550 was discussed in these composites prepared. Nancomposites were characterized by differential DSC, TGA, and scanning electron microscopy SEM. TGA results confirmed that the heat stability of the nano composite DABA/BMI/KH550 is improved compared with DABA/BMI system. SEM results indicated that the fumed silica dispersed homogeneously in DABA/BMI/KH550 matrix on nanoscale. Mechanical results shows that newly developed system has improved bending modulus to 4.0GPa, while with incorporation of fumed SiO2 impacted strength also improved to 20.60kJ/m2.

scholarly journals Analysis of Woven Fabric at the Place of the Sewn Seam

2018 ◽  
Vol 18 (3) ◽  
pp. 216-220 ◽  
Author(s):  
Beti Rogina-Car ◽  
Ivana Schwarz ◽  
Stana Kovačević
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Raw Material ◽  
Woven Fabric ◽  
Breaking Force ◽  
Time Intervals ◽  
Elongation At Break ◽  
Test Conditions ◽  
Stretching Intensity

Abstract Key importance and the role of sewn seam in the woven fabric are presented. Fabric properties in the places joined with the sewn seam on which garment durability, applicability, appearance and quality depend are highlighted. Seam location is usually the weakest spot on the garment, especially when the great loads are present at these places. Mechanical properties of the sewn fabrics were investigated in different test conditions. The influence of the load on the sewn seam is analyzed in time intervals. Sample with seam have approximately 70% lower breaking properties (breaking force and elongation at break) than the sample without seam. By preloading the seam fabrics with 30%, 50% and 70% of elongation at break, for a 3-h period, the effect on mechanical properties were tested and the differences in pre-stretching intensity were observed. By conducting such test, it is expected that the fabric experience further degradation and that breaking properties further reduce, but the exact opposite occurred (breaking properties, by increasing the preload, increase even more), because of various material properties (structural fabric properties, raw material characteristics, seam characteristics).

scholarly journals Mechanical Properties of Flexible TPU-Based 3D Printed Lattice Structures: Role of Lattice Cut Direction and Architecture

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2986
Author(s):  
Victor Beloshenko ◽  
Yan Beygelzimer ◽  
Vyacheslav Chishko ◽  
Bogdan Savchenko ◽  
Nadiya Sova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lattice Structure ◽  
Pore Space ◽  
Thermoplastic Polyurethane ◽  
Bending Tests ◽  
Three Point Bending ◽  
Lattice Materials ◽  
3D Printed ◽  
Anisotropy Of Mechanical Properties

This study addresses the mechanical behavior of lattice materials based on flexible thermoplastic polyurethane (TPU) with honeycomb and gyroid architecture fabricated by 3D printing. Tensile, compression, and three-point bending tests were chosen as mechanical testing methods. The honeycomb architecture was found to provide higher values of rigidity (by 30%), strength (by 25%), plasticity (by 18%), and energy absorption (by 42%) of the flexible TPU lattice compared to the gyroid architecture. The strain recovery is better in the case of gyroid architecture (residual strain of 46% vs. 31%). TPUs with honeycomb architecture are characterized by anisotropy of mechanical properties in tensile and three-point bending tests. The obtained results are explained by the peculiarities of the lattice structure at meso- and macroscopic level and by the role of the pore space.

scholarly journals Mechanical properties of solid glass bricks

2019 ◽  
Author(s):  
Jiří Fíla ◽  
Martina Eliášová ◽  
Zdeněk Sokol
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Building Materials ◽  
Flat Glass ◽  
Structural Elements ◽  
Compression Tests ◽  
Bending Tests ◽  
Load Bearing ◽  
Three Point Bending ◽  
Solid Glass

Glass as one of the oldest building materials has been used for centuries to fill window openings. In recent years is it increasingly used also for load-bearing structural elements such as beams, columns, ribs, railings, etc. In addition to flat glass and hollow glass blocks, which have been used historically for non-load-bearing partitions and facades, new load bearing structures from solid glass bricks are arising. Their greater use is hampered by a lack of knowledge of their material properties. Also, their joining is difficult, as can be seen from the realized structures and published works focused on the glass bricks masonry. Most often, transparent adhesives or special mortars are used on the joint between glass bricks. In addition to some examples of completed glass brick structures, the paper is aimed at determining the material properties of glass bricks, which are a prerequisite for the design of safe structures. Two sets of experiments were performed. There were made three-point bending tests and compression tests to determine the bending tensile strength, modulus of elasticity and compressive strength of glass bricks.

scholarly journals The structural role of bacterial eDNA in the formation of biofilm streamers

2021 ◽  
Author(s):  
Eleonora Secchi ◽  
Giovanni Savorana ◽  
Alessandra Vitale ◽  
Leo Eberl ◽  
Roman Stocker ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Polymeric Substances ◽  
Bacterial Resistance ◽  
Mechanical Stability ◽  
Antimicrobial Treatment ◽  
Geometric Constraints ◽  
Extracellular Dna ◽  
Clinical Settings ◽  
Biofilm Matrix

Across diverse habitats, bacteria are mainly found as biofilms, surface-attached communities embedded in a self-secreted matrix of extracellular polymeric substances (EPS), which enhances bacterial resistance to antimicrobial treatment and mechanical stresses. In the presence of flow and geometric constraints such as corners or constrictions, biofilms take the form of long, suspended threads known as streamers, which bear important consequences in industrial and clinical settings by causing clogging and fouling. The formation of streamers is thought to be driven by the viscoelastic nature of the biofilm matrix. Yet, little is known about the structural composition of streamers and how it affects their mechanical properties. Here, using a microfluidic platform that allows growing and precisely examining biofilm streamers, we show that extracellular DNA (eDNA) constitutes the backbone and is essential for the mechanical stability of Pseudomonas aeruginosa' s streamers. This finding is supported by the observations that DNA-degrading enzymes prevent the formation of streamers and clear already formed ones, and that the antibiotic ciprofloxacin promotes their formation by increasing the release of eDNA. Furthermore, using mutants for production of the exopolysaccharide Pel, an important component of P. aeruginosa' s EPS, we reveal a new, although indirect role of Pel, in tuning the mechanical properties of the streamers. Taken together, these results highlight the importance of eDNA and of its interplay with Pel in determining the mechanical properties of P. aeruginosa streamers, and suggest that targeting the composition of streamers can be an effective approach to control the formation of these biofilm structures.

scholarly journals Atomistic insights into the anisotropic mechanical properties and role of ripples on the thermal expansion of h-BCN monolayers

RSC Advances ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 1238-1246 ◽  
Author(s):  
Siby Thomas ◽  
Sang Uck Lee
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Mechanical Stability ◽  
Conducting Material ◽  
Anisotropic Mechanical Properties

2D h-BCN is a novel planar semi-conducting material akin to graphene and h-BN with high thermal mechanical stability suitable for the design of h-BCN-based composite materials.

Effect of Diabetes Mellitus on the Material Properties of the Distal Tibia

2006 ◽  
Vol 96 (2) ◽  
pp. 91-95 ◽  
Author(s):  
John G. Fleischli ◽  
Terese J. Laughlin ◽  
Kyriacos Athanasiou ◽  
Dan R. Lanctot ◽  
Lawrence Lavery ◽  
...  
Keyword(s):  
Yield Strength ◽  
Material Properties ◽  
Distal Tibia ◽  
Small Sample ◽  
Bending Tests ◽  
Three Point Bending ◽  
Bending Modulus ◽  
Human Male ◽  
Constant Rate ◽  
Strength And Stiffness

This investigation evaluates the effects of diabetes on the mechanical properties of human bone, specifically, the tibia. Seven diabetic and seven nondiabetic human (male) cadaveric distal tibiae were used in this study. The average age of the diabetic cadaveric samples was 51 years (range, 46–61 years), and the average age of the nondiabetic cadaveric samples was 75 years (range, 67–85 years). Three-point bending tests for strength and stiffness were performed on a small sample of each distal tibia. Each specimen was loaded at a constant rate until failure. From the recorded curve of load versus displacement, the ultimate and yield strength of bone and the bending modulus of bone were calculated. The diabetic samples were generally weaker than the older, nondiabetic samples, but no statistically significant differences were found in the elastic modulus (P = .29), yield strength (P = .90), ultimate strength (P = .46), and fracture toughness (P = .78), leading to speculation that diabetes has an effect similar to that of aging on the musculoskeletal system. (J Am Podiatr Med Assoc 96(2): 91–95, 2006)

scholarly journals Tensile Mechanical Properties and Dynamic Collagen Fiber Re-Alignment of the Murine Cervix Are Dramatically Altered Throughout Pregnancy

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Carrie E. Barnum ◽  
Jennifer L. Fey ◽  
Stephanie N. Weiss ◽  
Guillermo Barila ◽  
Amy G. Brown ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Preterm Birth ◽  
Material Properties ◽  
Time Course ◽  
Collagen Fiber ◽  
Structural Changes ◽  
Tensile Load ◽  
Primary Objective ◽  
Spontaneous Preterm Birth

The cervix is a unique organ able to dramatically change its shape and function by serving as a physical barrier for the growing fetus and then undergoing dramatic dilation allowing for delivery of a term infant. As a result, the cervix endures changing mechanical forces from the growing fetus. There is an emerging concept that the cervix may change or remodel “early” in many cases of spontaneous preterm birth (sPTB). However, the mechanical role of the cervix in both normal and preterm birth remains unclear. Therefore, the primary objective of this study was to determine the mechanical and structural responses of murine cervical tissue throughout a normal gestational time course. In this study, both tissue structural and material properties were determined via a quasi-static tensile load-to-failure test, while simultaneously obtaining dynamic collagen fiber re-alignment via cross-polarization imaging. This study demonstrated that the majority of the mechanical properties evaluated decreased at midgestation and not just at term, while collagen fiber re-alignment occurred earlier in the loading curve for cervices at term. This suggests that although structural changes in the cervix occur throughout gestation, the differences in material properties function in combination with collagen fiber re-alignment as mechanical precursors to regulate term gestation. This work lays a foundation for investigating cervical biomechanics and the role of the cervix in preterm birth.

An Artificial Neural Network Model to Predict Material Characteristics From the Results of Miniature Disk Bending Tests

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
A. K. Ghosh ◽  
Vishnu Verma ◽  
G. Behera
Keyword(s):  
Neural Network ◽  
Mechanical Properties ◽  
Inverse Problem ◽  
Artificial Neural Network ◽  
Material Properties ◽  
Artificial Neural Network Model ◽  
Large Database ◽  
Bending Tests ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

The inverse problem of evaluating mechanical properties of material from the observed values of load and deflection of a miniature disk bending specimen is discussed in this paper. It involves analysis of large amplitude, elasto-plastic deformation considering contact and friction. The approach in this work is to first generate—by a finite element (FE) solution—a large database of load-displacement (P-w) records for varying material properties. An artificial neural network (ANN) is trained with some of these data. The errors in the various values of the parameters during testing with additional known data were found to be reasonably small.

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