scholarly journals Effects of Morphological and Anatomical Characteristics of Banana Crown Vascular Bundles on Cutting Mechanical Properties Using Multiple Imaging Methods

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1199
Author(s):  
Lei Zhao ◽  
Haijun Yang ◽  
Heng Xie ◽  
Jieli Duan ◽  
Mohui Jin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Transition Region ◽  
Vascular Bundle ◽  
Small Range ◽  
Vascular Bundles ◽  
Anatomical Characteristics ◽  
Cutting Energy ◽  
Multiple Imaging ◽  
Central Stalk ◽  
X Ray Computed

To obtain the appropriate mechanized cutting region for banana dehanding, the methods of X-ray Computed Tomography (CT), Paraffin-embedded tissue section, and scanning electron microscopy (SEM) were adopted to observe the morphological and anatomical characteristics of vascular bundles of the banana crown. The results indicated that the crown can be divided into three regions, viz., the central stalk–crown transition region (CSCTR), the crown expansion region (CER), and the crown–finger transition region (CFTR). According to the obtained characteristics, the cutting mechanical properties are found to be affected by the relative angle between the vascular bundle and cutter (RAVBC) and the vascular bundle density. In CSCTR, due to the opposite change of RAVBC and density, the cutting mechanical properties become unstable and the cutting energy decreases gradually from 4.30 J to 2.57 J. While in CER, the cutting mechanical properties tend to be stable, and the cutting energy varies in a small range (2.83–2.92 J), owing to the small changes of RAVBC and density. When the vascular bundles cross from the CER to CFTR, the cutting energy increases with the increase of RAVBC and density, which varies from 3.37 to 4.84 J. Accordingly, the appropriate cutting region for dehanding, which can reduce the energy consumption and improve the cutting efficiency, is ascertained to be between CSCTR and CER.

scholarly journals Variation in Tensile Properties of Single Vascular Bundles in Moso Bamboo

2021 ◽  
Vol 71 (3) ◽  
pp. 246-251
Author(s):  
Lili Shang ◽  
Xing'e Liu ◽  
Zehui Jiang ◽  
Genlin Tian ◽  
Shumin Yang
Keyword(s):  
Mechanical Properties ◽  
Vascular Bundle ◽  
Longitudinal Direction ◽  
Functionally Graded ◽  
Moso Bamboo ◽  
Vascular Bundles ◽  
Fibrous Sheath ◽  
Bamboo Culm ◽  
Functionally Graded Composite ◽  
Bundle Structure

Abstract Moso bamboo (Phyllostachys edulis), an apt example of an anisotropic, functionally graded composite material, is the most important commercial bamboo species of China. This species has excellent mechanical properties due to its unique vascular bundle structure. This article examines the variation in mechanical properties of single vascular bundles with respect to their location within a bamboo culm. The mechanical exfoliation method was used to prepare the single vascular bundle. This study found that moso bamboo has superior stiffness and strength. Additionally, the variation in properties was large in the radial direction but minimal in longitudinal direction. The large variation in mechanical properties of vascular bundles can be ascribed to the synergistic effect of the fibrous sheath and parenchyma rather than to changes in fibrous sheath properties. This study provides a basis for the structure application for moso bamboo.

scholarly journals Correlation of the Areal Number Density of Vascular Bundles with the Mechanical Properties of Oil Palm Wood (Elaeis guineensis Jacq.)

2020 ◽  
Vol 9 (1) ◽  
pp. 4-7
Author(s):  
Rattana Choowang
Keyword(s):  
Mechanical Properties ◽  
Population Density ◽  
Vascular Bundle ◽  
Oil Palm ◽  
Elaeis Guineensis ◽  
Basic Density ◽  
Value Added ◽  
Modulus Of Rupture ◽  
Vascular Bundles ◽  
Elaeis Guineensis Jacq

Currently most of oil palm trunks in Thailand are left on the field to rot or are burnt in the field, not utilized as lumber. To promote such value-added uses, the objective of this study was to characterize the levels and variation within oil palm trunks of their key mechanical properties. In addition, the vascular bundle population was assessed, because this structural characteristic affected density and mechanical properties. The key ones being here were modulus of rupture (MOR), modulus of elasticity (MOE), and hardness. The 25 years old oil palm trunks were selected from a palm plantation in Surat Thani Province, in southern Thailand. The trees were cut down at 500 mm above ground, cut into dices, then sawn into small pieces in radial direction. Vascular bundle populations and basic densities were determined. Oil palm lumber was sawn from the logs between wood dices, and their mechanical properties were determined. The results indicated that the vascular bundle population density gradually decreased towards the central axis of trunks, and the population density positively correlated with basic density and mechanical properties. This was because the main component of a vascular bundle has fibers with thick cell walls. The data obtained may help select or create products that match the properties of oil palm wood (Elaeis guineensis Jacq.), or contributed to the sorting of wood raw material based on, for example, machine vision.

scholarly journals Knockout of Auxin Response Factor SlARF4 Improves Tomato Resistance to Water Deficit

2021 ◽  
Vol 22 (7) ◽  
pp. 3347
Author(s):  
Mengyi Chen ◽  
Xiaoyang Zhu ◽  
Xiaojuan Liu ◽  
Caiyu Wu ◽  
Canye Yu ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Vascular Bundle ◽  
Plant Resistance ◽  
Quantitative Polymerase Chain Reaction ◽  
Photochemical Efficiency ◽  
Differentially Expressed ◽  
Vascular Bundles ◽  
Aba Signaling ◽  
Auxin Response

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.

Preliminary Application of X-ray Computed Tomograph on Characterisation of Polish Gas Shale Mechanical Properties

2016 ◽  
Vol 49 (12) ◽  
pp. 4935-4943 ◽  
Author(s):  
M. Cała ◽  
K. Cyran ◽  
A. Stopkowicz ◽  
M. Kolano ◽  
M. Szczygielski
Keyword(s):  
Mechanical Properties ◽  
Gas Shale ◽  
X Ray ◽  
X Ray Computed ◽  
Computed Tomograph ◽  
Preliminary Application

scholarly journals Effect of Porosity on Mechanical Properties of 3D Printed Polymers: Experiments and Micromechanical Modeling Based on X-Ray Computed Tomography Analysis

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1154 ◽  
Author(s):  
Wang ◽  
Zhao ◽  
Fuh ◽  
Lee
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Micromechanical Model ◽  
Micromechanical Modeling ◽  
X Ray ◽  
Fused Deposition ◽  
3D Printed ◽  
X Ray Computed

Additive manufacturing (commonly known as 3D printing) is defined as a family of technologies that deposit and consolidate materials to create a 3D object as opposed to subtractive manufacturing methodologies. Fused deposition modeling (FDM), one of the most popular additive manufacturing techniques, has demonstrated extensive applications in various industries such as medical prosthetics, automotive, and aeronautics. As a thermal process, FDM may introduce internal voids and pores into the fabricated thermoplastics, giving rise to potential reduction on the mechanical properties. This paper aims to investigate the effects of the microscopic pores on the mechanical properties of material fabricated by the FDM process via experiments and micromechanical modeling. More specifically, the three-dimensional microscopic details of the internal pores, such as size, shape, density, and spatial location were quantitatively characterized by X-ray computed tomography (XCT) and, subsequently, experiments were conducted to characterize the mechanical properties of the material. Based on the microscopic details of the pores characterized by XCT, a micromechanical model was proposed to predict the mechanical properties of the material as a function of the porosity (ratio of total volume of the pores over total volume of the material). The prediction results of the mechanical properties were found to be in agreement with the experimental data as well as the existing works. The proposed micromechanical model allows the future designers to predict the elastic properties of the 3D printed material based on the porosity from XCT results. This provides a possibility of saving the experimental cost on destructive testing.

Nanoindentation Characterization of Lead-free Solders and Intermetallic Compounds under Thermal Aging

2010 ◽  
Vol 2010 (1) ◽  
pp. 000314-000318
Author(s):  
Tong Jiang ◽  
Fubin Song ◽  
Chaoran Yang ◽  
S. W. Ricky Lee
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Solder Joints ◽  
Lead Free ◽  
Small Range ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Aging Test ◽  
Free Solder ◽  
Lead Free Solders

The enforcement of environmental legislation is pushing electronic products to take lead-free solder alloys as the substitute of traditional lead-tin solder alloys. Applications of such alloys require a better understanding of their mechanical behaviors. The mechanical properties of the lead-free solders and IMC layers are affected by the thermal aging. The lead-free solder joints on the pads subject to thermal aging test lead to IMC growth and cause corresponding reliability concerns. In this paper, the mechanical properties of the lead-free solders and IMCs were characterized by nanoindentation. Both the Sn-rich phase and Ag3Sn + β-Sn phase in the lead-free solder joint exhibit strain rate depended and aging soften effect. When lead-free solder joints were subject to thermal aging, Young's modulus of the (Cu, Ni)6Sn5 IMC and Cu6Sn5 IMC changed in very small range. While the hardness value decreased with the increasing of the thermal aging time.

scholarly journals Mechanical behavior of 'Niagara Rosada' grape berry detachment

2011 ◽  
Vol 31 (6) ◽  
pp. 1115-1122 ◽  
Author(s):  
Daniel Gomes ◽  
Antonio C. de O Ferraz
Keyword(s):  
Mechanical Behavior ◽  
Vascular Bundle ◽  
Traction Force ◽  
Grape Berry ◽  
Vascular Bundles ◽  
Test Results ◽  
Deformation Curves ◽  
Considerable Portion ◽  
Surrounding Skin ◽  
Niagara Rosada

The 'Niagara Rosada' grape is the main Brazilian table grape belonging to the Labrusca family. It develops medium, cylindrical and compact bunches with berries presenting a pinkish skin and a foxy flavor that is valued in the Brazilian market. These berries are tender and have a pedicel-berry connection provided by the vascular bundles and surrounding skin. This cultivar is very susceptible to berry drop mainly caused by vibration and senescence. The objective of this study was to evaluate the temporal mechanical behavior of the pedicel-berry detachment, using resistance indexes extracted from traction force-deformation curves. Test results showed two different detachment types. In the first one, which exhibited higher average resistance, a considerable portion of the vascular bundle came out attached to the pedicel and in the second type; the vascular bundle was retained inside the berry. The proposed indexes based on maximum detachment force, force at 0.2; 0.5; 1.0 and 1.2 mm, and maximum force to corresponding deformation ratio did not discriminate the senescence of the berry.

Early ontogeny defines the diversification of primary vascular bundle systems in angiosperms

2020 ◽  
Author(s):  
Regine Claßen-Bockhoff ◽  
Doris Franke ◽  
Hansjörg Krähmer
Keyword(s):  
Vascular Bundle ◽  
Vascular Tissue ◽  
Three Dimensional ◽  
Early Ontogeny ◽  
Leaf Primordia ◽  
Dimensional System ◽  
Vascular Bundles ◽  
Histological Data ◽  
Molecular Aspects ◽  
The One

Abstract Understanding vascular bundle systems in angiosperms is a challenge. On the one hand, the vascular tissue is extremely important in reconstructing the evolution and survivability of plants, but on the other hand, it forms a complicated three-dimensional system of controversially discussed phylogenetic and ontogenetic origin. To increase clarity, in this paper we briefly summarize histological, phylogenetic and molecular aspects of primary vascular bundle formation in angiosperms, adding histological data on early stages of vascular bundle formation, proposing a concept combining the different views and providing simplified illustrations to improve the understanding of primary vascular systems in angiosperms. Based on the auxin hypothesis, vascular bundle formation is stimulated by the development of leaf primordia. Provascular domains appear at the base of the leaf primordia and develop into two directions (leaf, internode). The low vs. high number of internodal bundles, their circular vs. scattered arrangement and the open vs. closed bundle construction in eudicots vs. monocots can be deduced to be due to processes below the shoot apical meristem. The most important processes distinguishing monocots from eudicots are the isolated bundle initiation outside the primary meristem, the enormous expansion of the leaf bases associated with a high number of vascular bundles and the early onset of primary thickening passively dislocating vascular bundles.

Ab Initio Study on Continuous Evolution of Mechanical Properties in Phase‐Transition Region of Low‐Carbon Steel

2020 ◽  
Vol 91 (8) ◽  
pp. 2000070
Author(s):  
Songyuan Ai ◽  
Mujun Long ◽  
Wei Guo ◽  
Peng Liu ◽  
Dengfu Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transition ◽  
Carbon Steel ◽  
Ab Initio ◽  
Transition Region ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Ab Initio Study ◽  
Continuous Evolution ◽  
Phase Transition Region
Sign in / Sign up

Export Citation Format

Share Document