scholarly journals Embolism resistance in petioles and leaflets of palms

2019 ◽  
Vol 124 (7) ◽  
pp. 1173-1183 ◽  
Author(s):  
Thaise Emilio ◽  
Laurent J Lamarque ◽  
José M Torres-Ruiz ◽  
Andrew King ◽  
Guillaume Charrier ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Xylem Embolism ◽  
Phylogenetic Relatedness ◽  
X Ray ◽  
Xylem Pressure ◽  
Palm Species ◽  
Embolism Resistance ◽  
Increasing Temperature

Abstract Background and aims Hydraulic studies are currently biased towards conifers and dicotyledonous angiosperms; responses of arborescent monocots to increasing temperature and drought remain poorly known. This study aims to assess xylem resistance to drought-induced embolism in palms. Methods We quantified embolism resistance via P50 (xylem pressure inducing 50 % embolism or loss of hydraulic conductivity) in petioles and leaflets of six palm species differing in habitat and phylogenetic relatedness using three techniques: in vivo X-ray-based microcomputed tomography, the in situ flow centrifuge technique and the optical vulnerability method. Key results Our results show that P50 of petioles varies greatly in the palm family, from −2.2 ± 0.4 MPa in Dypsis baronii to −5.8 ± 0.3 MPa in Rhapis excelsa (mean ± s.e.). No difference or weak differences were found between petioles and leaf blades within species. Surprisingly, where differences occurred, leaflets were less vulnerable to embolism than petioles. Embolism resistance was not correlated with conduit size (r = 0.37, P = 0.11). Conclusions This study represents the first estimate of drought-induced xylem embolism in palms across biomes and provides the first step towards understanding hydraulic adaptations in long-lived arborescent monocots. It showed an almost 3-fold range of embolism resistance between palm species, as large as that reported in all angiosperms. We found little evidence for hydraulic segmentation between leaflets and petioles in palms, suggesting that when it happens, hydraulic segregation may lack a clear relationship with organ cost or replaceability.

I1̄ – I2/c ferroelastic phase transition in the Ca0.2Pb0.8Al2Si2O8 feldspar as a function of temperature

2000 ◽  
Vol 64 (2) ◽  
pp. 285-290 ◽  
Author(s):  
P. Benna ◽  
M. Tribaudino ◽  
E. Bruno
Keyword(s):  
Room Temperature ◽  
Monoclinic Phase ◽  
Strain Tensor ◽  
Spontaneous Strain ◽  
Linear Coupling ◽  
X Ray ◽  
Ferroelastic Phase Transition ◽  
Increasing Temperature ◽  
Alkali Feldspars

AbstractFeldspar of composition Ca0.2Pb0.8Al2Si2O8 (PbF80An20) was synthesized from melt and subsequently isothermally annealed at T = 960°C for 4 days. In situ HT X-ray powder spectra of PbF80An20 feldspar, triclinic I1̄ at room temperature, were collected in the temperature range 20–800°C, and a displacive continuous ferroelastic transition to a I2/c monoclinic phase was observed. An analysis of the symmetry-required components of the spontaneous strain tensor reveals the second order character (β = 0.46 ± 0.02) of the transition with TC = 680 ± 15°C. A linear coupling was observed between the e4 and e6 components of the spontaneous strain. The transition is analogous to those observed, with increasing temperature, along the join An–SrF and in disordered Na-rich alkali feldspars. A comparison with Ca0.2Sr0.8Al2Si2O8 feldspar (TC = 680°C, McGuinn and Redfern, 1997) shows that PbF80An20 has a higher spontaneous strain (εs = 0.028 in PbF80An20vs 0.020 in Ca0.2Sr0.8Al2Si2O8) and a higher e4 component, possibly related to the higher distortion of the non-tetrahedral polyhedron in lead feldspar.

scholarly journals Development of a sticker sealed microfluidic device for in situ analytical measurements using synchrotron radiation

2021 ◽  
Author(s):  
ITAMAR NECKEL ◽  
Lucas F. de Castro ◽  
Flavia Callefo ◽  
Verônica Teixeira ◽  
Angelo Gobbi ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Green Energy ◽  
X Rays ◽  
Electrical Measurements ◽  
X Ray ◽  
Electrochemical Nucleation ◽  
Synchrotron Light

Abstract Shedding synchrotron light on microfluidic systems, exploring several contrasts in situ operando at the nanoscale, like X-ray fluorescence, diffraction, luminescence, and absorption, has the potential to reveal new properties and functionalities of materials across diverse areas, such as green energy, photonics, and nanomedicine. In this work, we present the micro-fabrication and characterization of a multifunctional polyester/glass sealed microfluidic device well-suited to combine with analytical X-ray techniques. The device consists of smooth microchannels patterned on glass, where three gold electrodes are deposited into the channels to serve in situ electrochemistry analysis or standard electrical measurements. It has been efficiently sealed through an ultraviolet-sensitive sticker-like layer based on a polyester film, and The burst pressure determined by pumping water through the microchannel(up to 0.22 MPa). Overall, the device has demonstrated exquisite chemical resistance to organic solvents, and its efficiency in the presence of biological samples (proteins) is remarkable. The device potentialities, and its high transparency to X-rays, have been demonstrated by taking advantage of the X-ray nanoprobe Carnaúba/Sirius/LNLS, by obtaining 2D X-ray nanofluorescence maps on the microchannel filled with water and after an electrochemical nucleation reaction. To wrap up, the microfluidic device characterized here has the potential to be employed in standard laboratory experiments as well as in situ and in vivo analytical experiments using a wide electromagnetic window, from infrared to X-rays, which could serve experiments in many branches of science.

Static X-Ray Scans on the Titanium Hydride (TiH2) Powder during Dehydrogenation

2013 ◽  
Vol 795 ◽  
pp. 124-127 ◽  
Author(s):  
Nur Farhana Hayazi ◽  
Yu Wang ◽  
Mohd Noor Mazlee ◽  
Sammy Lap Ip Chan
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Isothermal Heating ◽  
X Ray ◽  
Refinement Method ◽  
Increasing Temperature

This work investigates the dehydrogenation of TiH2 powder during isothermal heating at 600°C using the static x-ray scans of high temperature x-ray diffraction (XRD). As-received TiH2 powder with a particle size of 5 μm and purity of 99.1% was used for this measurement. With increasing temperature, phase transformations occurred because of dehydrogenation and it happened very fast. It was found that during the phase transformation of TiH2 to titanium, some transitional phases observed and occurred. This finding confirmed the in-situ determination of TiH2 powder dehydrogenation by using Rietveld Refinement Method from our previous research. This study is useful for the fabrication of titanium-based composites and titanium alloys from TiH2 powder because the different phases in TiH2 will affect the final mechanical properties in titanium.

scholarly journals An Experimental Study of the Formation of Talc through CaMg(CO3)2–SiO2–H2O Interaction at 100–200°C and Vapor-Saturation Pressures

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ye Wan ◽  
Xiaolin Wang ◽  
I-Ming Chou ◽  
Wenxuan Hu ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Fused Silica ◽  
X Ray Diffraction ◽  
In Situ Raman Spectroscopy ◽  
X Ray ◽  
In Situ Raman ◽  
Geological Processes ◽  
Partial Pressures ◽  
Increasing Temperature

The metamorphic interaction between carbonate and silica-rich fluid is common in geological environments. The formation of talc from dolomite and silica-rich fluid occurs at low temperatures in the metamorphism of the CaO–MgO–SiO2–CO2–H2O system and plays important roles in the formation of economically viable talc deposits, the modification of dolomite reservoirs, and other geological processes. However, disagreement remains over the conditions of talc formation at low temperatures. In this study, in situ Raman spectroscopy, quenched scanning electron microscopy, micro-X-ray diffraction, and thermodynamic calculations were used to explore the interplay between dolomite and silica-rich fluids at relatively low temperatures in fused silica tubes. Results showed that talc formed at ≤200°C and low CO2partial pressures (PCO2). The reaction rate increased with increasing temperature and decreased with increasingPCO2. The major contributions of this study are as follows:(1)we confirmed the formation mechanism of Mg-carbonate-hosted talc deposits and proved that talc can form at ≤200°C;(2)the presence of talc in carbonate reservoirs can indicate the activity of silica-rich hydrothermal fluids; and (3) the reactivity and solubility of silica require further consideration, when a fused silica tube is used as the reactor in highP–Texperiments.

X-ray Visible and Uniform Alginate Microspheres Loaded with in Situ Synthesized BaSO4 Nanoparticles for in Vivo Transcatheter Arterial Embolization

2015 ◽  
Vol 16 (4) ◽  
pp. 1240-1246 ◽  
Author(s):  
Qin Wang ◽  
Kun Qian ◽  
Shanshan Liu ◽  
Yajiang Yang ◽  
Bin Liang ◽  
...  
Keyword(s):  
Transcatheter Arterial Embolization ◽  
Arterial Embolization ◽  
X Ray

scholarly journals A Study of Recrystallization and Phase Transitions in Intermetallic Titanium Aluminides by In Situ High-Energy X-Ray Diffraction

2007 ◽  
Vol 539-543 ◽  
pp. 1519-1524 ◽  
Author(s):  
Klaus Dieter Liss ◽  
A. Bartels ◽  
Helmut Clemens ◽  
S. Bystrzanowski ◽  
A. Stark ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Titanium Aluminides ◽  
Strain Relaxation ◽  
High Energy ◽  
Internal Stresses ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Heating ◽  
Increasing Temperature

High-energy synchrotron X-ray diffraction is a novel and powerful tool for bulk studies of materials. In this study, it is applied for the investigation of an intermetallic γ-TiAl based alloy. Not only the diffraction angles, but also the morphology of reflections on the Debye-Scherrer rings are evaluated in order to approach lattice parameters and grain sizes as well as crystallographic relationships. An in-situ heating cycle from room temperature to 1362 °C has been conducted starting from massively transformed γ-TiAl which exhibits high internal stresses. With increasing temperature the occurrence of strain relaxation, chemical and phase separation, domain orientations, phase transitions, recrystallization processes, and subsequent grain growth can be observed. The data obtained by high-energy synchrotron X-ray diffraction, extremely rich in information, are interpreted step by step.

scholarly journals On the Structural Peculiarities of Self-Reinforced Composite Materials Based on UHMWPE Fibers

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1408
Author(s):  
Dmitry Zherebtsov ◽  
Dilyus Chukov ◽  
Isabelle Royaud ◽  
Marc Ponçot ◽  
Ilya Larin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Compaction Pressure ◽  
Polarized Light ◽  
Tensile Tests ◽  
X Ray ◽  
Hot Compaction ◽  
The Matrix ◽  
Uhmwpe Fibers ◽  
Increasing Temperature

The structure of self-reinforced composites (SRCs) based on ultra-high molecular weight polyethylene (UHMWPE) was studied by means of Wide-Angle X-ray Scattering (WAXS), X-ray tomography, Raman spectroscopy, Scanning Electron Microscopy (SEM) and in situ tensile testing in combination with advanced processing tools to determine the correlation between the processing conditions, on one hand, and the molecular structure and mechanical properties, on the other. SRCs were fabricated by hot compaction of UHMWPE fibers at different pressure and temperature combinations without addition of polymer matrix or softener. It was found by WAXS that higher compaction temperatures led to more extensive melting of fibers with the corresponding reduction of the Herman’s factor reflecting the degree of molecular orientation, while the increase of hot compaction pressure suppressed the melting of fibers within SRCs at a given temperature. X-ray tomography proved the absence of porosity while polarized light Raman spectroscopy measurements for both longitudinal and perpendicular fiber orientations showed qualitatively the anisotropy of SRC samples. SEM revealed that the matrix was formed by interlayers of molten polymer entrapped between fibers in SRCs. Moreover, in situ tensile tests demonstrated the increase of Young’s modulus and tensile strength with increasing temperature.

scholarly journals Development of a sticker sealed microfluidic device for in situ analytical measurements using synchrotron radiation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Itamar T. Neckel ◽  
Lucas F. de Castro ◽  
Flavia Callefo ◽  
Verônica C. Teixeira ◽  
Angelo L. Gobbi ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Green Energy ◽  
X Rays ◽  
Electrical Measurements ◽  
X Ray ◽  
Electrochemical Nucleation ◽  
Synchrotron Light

AbstractShedding synchrotron light on microfluidic systems, exploring several contrasts in situ/operando at the nanoscale, like X-ray fluorescence, diffraction, luminescence, and absorption, has the potential to reveal new properties and functionalities of materials across diverse areas, such as green energy, photonics, and nanomedicine. In this work, we present the micro-fabrication and characterization of a multifunctional polyester/glass sealed microfluidic device well-suited to combine with analytical X-ray techniques. The device consists of smooth microchannels patterned on glass, where three gold electrodes are deposited into the channels to serve in situ electrochemistry analysis or standard electrical measurements. It has been efficiently sealed through an ultraviolet-sensitive sticker-like layer based on a polyester film, and The burst pressure determined by pumping water through the microchannel(up to 0.22 MPa). Overall, the device has demonstrated exquisite chemical resistance to organic solvents, and its efficiency in the presence of biological samples (proteins) is remarkable. The device potentialities, and its high transparency to X-rays, have been demonstrated by taking advantage of the X-ray nanoprobe Carnaúba/Sirius/LNLS, by obtaining 2D X-ray nanofluorescence maps on the microchannel filled with water and after an electrochemical nucleation reaction. To wrap up, the microfluidic device characterized here has the potential to be employed in standard laboratory experiments as well as in in situ and in vivo analytical experiments using a wide electromagnetic window, from infrared to X-rays, which could serve experiments in many branches of science.

Real time In Situ X-Ray Topographic Observation of Deformation of Single Crystals and Thin Films

1998 ◽  
Vol 524 ◽  
Author(s):  
Z. B. Zhao ◽  
J. Hershberger ◽  
A. Chiaramonti ◽  
Z. U. Rek ◽  
J. C. Bilello
Keyword(s):  
Real Time ◽  
X Ray ◽  
Mechanical Cycling ◽  
Experimental Apparatus ◽  
Tensile Data ◽  
Deformation Behaviors ◽  
Deformation Processes ◽  
Increasing Temperature ◽  
Increasing Load

ABSTRACTAn experimental apparatus, which is capable of performing real time in situ X-ray topographic observation of deformation process via synchrotron white beam topography, has been developed. This device enables both tensile data (load-displacement) and topographic images to be recorded simultaneously. It has been utilized to study the deformation behaviors of crystals of Mo and W.These specimens have been subject to mechanical cycling with increasing load, and their deformation processes have been observed in real time and in situ via x-ray topography. This leads to the observation of several phenomena, which would have been difficult to reveal by other experimental techniques. They include stress concentration, microyielding, reversible variation of contrasts and stress relaxation. In addition, the deformation behaviors of small angle grain boundaries have also been examined. Furthermore, the specimens can be heated through a heating device attached to the tensile stage, which allows high temperature topography to be performed in real time. The technique has been applied to the Ta films on Si (100) substrates. With increasing temperature, the topographic observations have revealed that the Ta films yield, fracture and then proceed to delaminate from their substrates.

Effects of osmotic gradients on water and solute transport: in vivo studies in rat duodenum and ileum.

1979 ◽  
Vol 237 (4) ◽  
pp. E389 ◽  
Author(s):  
D L Miller ◽  
S A Hamburger ◽  
H P Schedl
Keyword(s):  
Sodium Chloride ◽  
Hydraulic Conductivity ◽  
In Vivo Studies ◽  
Sodium Absorption ◽  
Solute Movement ◽  
Rat Duodenum ◽  
Water Secretion ◽  
Water And Solute Transport

We examined effects of luminal osmolality on net water and solute movements in rat duodenum and ileum. Solutions of sodium chloride (permeating solute) or mannitol (nonpermeating solute) at hypo-, iso-, or hyperosmotic concentrations were recirculated through in situ segments. Luminal osmolality increased towards that of plasma with hyposmotic solutions of both solutes. With isosmotic solutions, luminal osmolality did not change with sodium chloride, but increased with mannitol. With hyperosmotic solutions, luminal osmolality always decreased toward that of plasma with sodium chloride; with mannitol, however, decreases were significant only when initial concentrations were above 400 mosmol/kg. The decrease in osmolality of hyperosmotic sodium chloride resulted from sodium absorption and water secretion. Thus, both hypo- and hyperosmotic solutions of sodium chloride adjusted toward isomolality with plasma by the usual mechanisms of water and solute movement. With mannitol, however, osmotic adjustment of hypertonic luminal contents was restricted or even absent due to movement of sodium down its concentration gradient and reduced hydraulic conductivity of the gut.

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