scholarly journals Diffusion of water in palm leaf materials

2021 ◽  
Vol 18 (185) ◽  
Author(s):  
Debapriya Pinaki Mohanty ◽  
Anirudh Udupa ◽  
Koushik Viswanathan ◽  
Christopher J. Gilpin ◽  
Srinivasan Chandrasekar ◽  
...  
Keyword(s):  
Water Transport ◽  
Mass Gain ◽  
Leaf Sheath ◽  
Image Correlation ◽  
Plant Materials ◽  
Order Of Magnitude ◽  
Strength And Stiffness ◽  
Material Swelling ◽  
Palm Leaf

Diffusion of water into plant materials is known to decrease their mechanical strength and stiffness but improve formability. Here, we characterize water diffusion through areca palm leaf-sheath—a model plant material, with hierarchical structure, used in eco-friendly foodware. The diffusion process is studied using mass gain measurements and in situ imaging of water transport. By treating the areca sheath as homogeneous ensemble, and incorporating effects of material swelling due­ to water absorption, a factor typically neglected in prior studies, the diffusion coefficient D w for water is estimated as (6.5 ± 2.2) × 10 −4 mm 2 s −1 . It is shown that neglecting the swelling results in gross underestimation of D w . Microstructural effects (e.g. fibre, matrix) on the diffusion are characterized using in situ imaging of the water transport at high resolution. The observations show that the water diffuses an order of magnitude faster in the matrix (8.63 × 10 −4 mm 2 s −1 ) than in the fibres (7.19 × 10 −5 mm 2 s −1 ). This non-uniformity is also reflected in the swelling-induced strain in the leaf, mapped by image correlation. Lastly, we vary salt concentration by controlled additions of NaCl and note a non-monotonic dependence of the diffusion on concentration. Implications of the results for improving foodware manufacturing processes and product life are discussed.

BEHAVIOR OF PLASTIC DEFORMATION AND CRACK PROPAGATION ON FULLY LAMELLAR GAMMA-TiAl ALLOY

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2958-2963
Author(s):  
MING SONG ◽  
GUANGJIE MAO ◽  
YUE MA ◽  
SHENGKAI GONG
Keyword(s):  
Plastic Deformation ◽  
Plastic Zone ◽  
Strain Field ◽  
Tial Alloy ◽  
Image Correlation ◽  
Deformation Region ◽  
Order Of Magnitude ◽  
Plastic Deformation Region ◽  
Fully Lamellar

Practical residual strain field around the microcrack tip of fully lamellar γ- TiAl alloy was estimate the by digital image correlation (DIC) technology with in-situ SEM observation. And the macro plastic deformation before fracture of such low ductility alloys was observed. The results showed that the size of plastic zone around microcrack tip was 2 ~ 10µ m which was much more smaller than the calculated value by fracture mechanics. During the magnified observation on the plastic deformation region, a series of microcracks were observed in the specimen without macro cracking. Furthermore, the size of distribution region of the microcracks were in the same order of magnitude with the calculated plastic zone near primary crack tip which just reflected the comprehensive effect of microcracks and the plastic deformation on the tips of them.

In Situ Formation of Poly(ethylene naphthalate) Microfibres in Polyethylene and Polypropylene during Extrusion

2007 ◽  
Vol 334-335 ◽  
pp. 161-164 ◽  
Author(s):  
Ka Lok Leung ◽  
Allan J. Easteal ◽  
Debes Bhattacharyya
Keyword(s):  
Tensile Strength ◽  
Scanning Electron Micrographs ◽  
Polyolefin Blends ◽  
Extrusion Die ◽  
Order Of Magnitude ◽  
Poly Ethylene ◽  
Strength And Stiffness ◽  
The Relationship ◽  
Fibre Morphology

Tensile properties and morphology of poly(ethylene naphthalate)/polyolefin blends and the relationship with the extrusion die size were investigated. Scanning electron micrographs of the blends reveal that the fibre morphology is developed during extrusion through the die. Skin-core morphology has been observed. As die diameter decreases, a droplet-to-fibre transition in morphology increases tensile strength and stiffness. After microfibrillization, up to 100% increase in the tensile stiffness was observed and the tensile strength could increase by one order of magnitude.

In situ short-term growth rates of a cold-water coral

2013 ◽  
Vol 64 (7) ◽  
pp. 631 ◽  
Author(s):  
C. Jantzen ◽  
J. Laudien ◽  
S. Sokol ◽  
G. Försterra ◽  
V. Häussermann ◽  
...  
Keyword(s):  
Growth Rates ◽  
Cold Water ◽  
Mass Gain ◽  
Natural Environments ◽  
Lower Growth ◽  
Order Of Magnitude ◽  
Desmophyllum Dianthus ◽  
Flow Through ◽  
Water Coral

Cold-water corals are known to grow much slower than their tropical counterparts. However, this assumption is mainly based on laboratory measurements exposing specimens to conditions that differ from their natural environments. The cosmopolitan scleractinian Desmophyllum dianthus forms dense banks below 18 m in northern Patagonia, Chile. So as to measure in situ growth rates of this cold-water coral, specimens were collected from two sites, weighed and deployed on holders in their natural headlong orientation at the respective collecting site. Corals exhibited a calcium carbonate (CaCO3) mass increase of 5.44 ± 3.45 (mg (cm2 projected calyx area)–1 day–1) after 2 weeks, equivalent to a mass gain of 0.25 ± 0.18 s.d. % day–1. In comparison, D. dianthus specimens from the same collection sites maintained in an on-site flow-through aquarium system showed lower growth rates that were third of the in situ rates. In situ CaCO3 precipitation of D. dianthus extrapolated for 1 year (kg m2 year–1) displays the same order of magnitude as reported for massive growing tropical scleractinians, e.g. Porites sp.

scholarly journals Localization of Ruminal Cellulolytic Bacteria on Plant Fibrous Materials as Determined by Fluorescence In Situ Hybridization and Real-Time PCR

2007 ◽  
Vol 73 (5) ◽  
pp. 1646-1652 ◽  
Author(s):  
Takumi Shinkai ◽  
Yasuo Kobayashi
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Real Time ◽  
Real Time Pcr ◽  
Leaf Sheath ◽  
Phylogenetic Group ◽  
Gene Copy ◽  
Plant Materials ◽  
Group 1

ABSTRACT To visualize and localize specific bacteria associated with plant materials, a new fluorescence in situ hybridization (FISH) protocol was established. By using this protocol, we successfully minimized the autofluorescence of orchard grass hay and detected rumen bacteria attached to the hay under a fluorescence microscope. Real-time PCR assays were also employed to quantitatively monitor the representative fibrolytic species Fibrobacter succinogenes and Ruminococcus flavefaciens and also total bacteria attached to the hay. F. succinogenes was found firmly attached to not only the cut edges but also undamaged inner surfaces of the hay. Cells of phylogenetic group 1 of F. succinogenes were detected on many stem and leaf sheath fragments of the hay, even on fragments on which few other bacteria were seen. Cells of phylogenetic group 2 of F. succinogenes were often detected on hay fragments coexisting with many other bacteria. On the basis of 16S rRNA gene copy number analysis, the numbers of bacteria attached to the leaf sheaths were higher than those attached to the stems (P < 0.05). In addition, R. flavefaciens had a greater tendency than F. succinogenes to be found on the leaf sheath (P < 0.01) with formation of many pits. F. succinogenes, particularly phylogenetic group 1, is suggested to possibly play an important role in fiber digestion, because it is clearly detectable by FISH and is the bacterium with the largest population size in the less easily degradable hay stem.

Atomic Layer Deposition of LiF and Lithium Ion Conducting (AlF3)(LiF)x Alloys Using Trimethylaluminum, Lithium Hexamethyldisilazide and Hydrogen Fluoride

2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Atomic Layer ◽  
Mass Gain ◽  
Alloy Film ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Ion Conducting ◽  
Good Agreement

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>

scholarly journals Digital Image Correlation for Evaluation of Cracks in Reinforced Concrete Bridge Slabs

2021 ◽  
Vol 6 (7) ◽  
pp. 99
Author(s):  
Christian Overgaard Christensen ◽  
Jacob Wittrup Schmidt ◽  
Philip Skov Halding ◽  
Medha Kapoor ◽  
Per Goltermann
Keyword(s):  
Reinforced Concrete ◽  
Digital Image Correlation ◽  
Crack Initiation ◽  
Laboratory Test ◽  
Digital Image ◽  
Crack Detection ◽  
Image Correlation ◽  
In Situ Tests ◽  
Stop Criterion

In proof-loading of concrete slab bridges, advanced monitoring methods are required for identification of stop criteria. In this study, Two-Dimensional Digital Image Correlation (2D DIC) is investigated as one of the governing measurement methods for crack detection and evaluation. The investigations are deemed to provide valuable information about DIC capabilities under different environmental conditions and to evaluate the capabilities in relation to stop criterion verifications. Three Overturned T-beam (OT) Reinforced Concrete (RC) slabs are used for the assessment. Of these, two are in situ strips (0.55 × 3.6 × 9.0 m) cut from a full-scale OT-slab bridge with a span of 9 m and one is a downscaled slab tested under laboratory conditions (0.37 × 1.7 × 8.4 m). The 2D DIC results includes full-field plots, investigation of the time of crack detection and monitoring of crack widths. Grey-level transformation was used for the in situ tests to ensure sufficient readability and results comparable to the laboratory test. Crack initiation for the laboratory test (with speckle pattern) and in situ tests (plain concrete surface) were detected at intervals of approximately 0.1 mm to 0.3 mm and 0.2 mm to 0.3 mm, respectively. Consequently, the paper evaluates a more qualitative approach to DIC test results, where crack indications and crack detection can be used as a stop criterion. It was furthermore identified that crack initiation was reached at high load levels, implying the importance of a target load.

Methodology for in situ stress intensity factor determination on cracked structures by digital image correlation

2010 ◽  
Vol 1 (4) ◽  
pp. 344-357 ◽  
Author(s):  
V. Richter‐Trummer ◽  
P.M.G.P. Moreira ◽  
S.D. Pastrama ◽  
M.A.P. Vaz ◽  
P.M.S.T. de Castro
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Digital Image Correlation ◽  
Intensity Factor ◽  
Digital Image ◽  
Strain Field ◽  
Image Correlation ◽  
Content Type ◽  
Cracked Structures

PurposeThe purpose of this paper is to develop a methodology for in situ stress intensity factor (SIF) determination that can be used for the analysis of cracked structures. The technique is based on digital image correlation (DIC) combined with an overdetermined algorithm.Design/methodology/approachThe linear overdeterministic algorithm for calculating the SIF based on stress values around the crack tip is applied to a strain field obtained by DIC.FindingsAs long as the image quality is sufficiently high, a good accuracy can be obtained for the measured SIF. The crack tip can be automatically detected based on the same strain field. The use of the strain field instead of the displacement field, eliminates problems related to the rigid body motion of the analysed structure.Practical implicationsIn future works, based on the applied techniques, the SIF of complex cracked plane stress structures can be accurately determined in real engineering applications.Originality/valueThe paper demonstrates application of known techniques, refined for other applications, also the use of stress field for SIF overdeterministic calculations.

In Situ Biaxial Mechanical Testing at the Neutron Time-of-Flight Diffractometer POLDI

2013 ◽  
Vol 768-769 ◽  
pp. 60-65 ◽  
Author(s):  
Julia Repper ◽  
Markus Niffenegger ◽  
Steven van Petegem ◽  
Werner Wagner ◽  
Helena van Swygenhoven
Keyword(s):  
Steel Sample ◽  
Mechanical Tests ◽  
Image Correlation ◽  
Uniaxial Deformation ◽  
Spatially Resolved ◽  
Neutron Diffractometer ◽  
Neutron Time ◽  
Strain Paths ◽  
Biaxial Mechanical Testing

Complex strain paths are often applied to materials during production processes. This paper shows the first successful in-situ biaxial mechanical tests during neutron diffraction performed on a cruciform steel sample and reports on the differences compared to uniaxial deformation. Digital image correlation is demonstrated to be an appropriate tool to monitor spatially resolved the macroscopic straining. The new, modular biaxial machine that will be installed at the neutron diffractometer POLDI is presented.

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